I-atikili le yingcenye yesihloko serhubhululo esithi “Amathekhnoloji athuthukileko wokulungisa izinto eziphilako kanye neenkambo zokubuyisela kabutjha amakhompawundi wezinto eziphilako (i-SOC)”. Qala woke ama-atikili ali-14
Ama-polycyclic aromatic hydrocarbons (ama-PAH) anesisindo esiphasi afana ne-naphthalene kanye nama-naphthalenes athathelwe indawo (i-methylnaphthalene, i-naphthoic acid, i-1-naphthyl-N-methylcarbamate, njll.) asetjenziswa khulu emabubulweni ahlukahlukeneko begodu ayi-genotoxic, ayi-mutagenic kanye/noma ayi-carcinogenic. Amakhompawundi wezinto eziphilako (ama-SOC) nofana ama-xenobiotics athathwa njengezinto ezisilaphazako eziqakathekileko begodu abeka ingozi ekulu emvelweni wephasi loke nepilo yomphakathi. Ukuqina kwemisebenzi yabantu (isib. ukukhiqizwa kwamalahle, ukucwengisiswa kwamafutha, ukukhutjhwa kwekhaboni ngeenkoloyi nokusetjenziswa kwezokulima) kunquma ukugxila, isiphetho nokuthuthwa kwamakhompawundi la akhona yoke indawo begodu aphikelelako. Ngaphezu kweendlela zokulapha/ukususa ngamakhemikhali, ubuchwepheshe obuhlaza nobungani ibhoduluko obufana ne-bioremediation, obusebenzisa ama-microorganisms akghona ukuwohloka ngokupheleleko ama-POC nofana ukuwatjhugulula abe mikhiqizo enganabuthi, sele ivele njengenye indlela ephephileko, engabiziko nethembisako. Iinhlobo ezihlukahlukeneko zamabhaktheriya ezivela e-phyla Proteobacteria (i-Pseudomonas, i-Pseudomonas, i-Comamonas, i-Burkholderia, kanye ne-Neosphingobacterium), i-Firmicutes (i-Bacillus ne-Paenibacillus), kanye ne-Actinobacteria (i-Rhodococcus ne-Arthrobacter) emhlabathini zitjengise amandla wokuwohloka kwezinto eziphilako ezihlukahlukeneko. Iimfundo ze-metabolic, i-genomics, nokuhlaziywa kwe-metagenomic kusisiza sizwisise ubudisi be-catabolic nokuhlukahluka okukhona eentweni ezilula eziphilako, ezingasetjenziselwa ukuwohloka kwezinto eziphilako. Ubukhona besikhathi eside bama-PAH bubangele ukuvela kwama-phenotypes wokuwohloka ngokusebenzisa ukudluliselwa kwezakhi zofuzo okuvundlileko kusetjenziswa izinto zofuzo ezifana nama-plasmid, ama-transposon, ama-bacteriophages, iinhlenge ze-genomic, kanye nama-elementi ahlanganisiweko. Isayensi yebhayoloji kanye nobunjiniyela bezakhi zofuzo bezinto ezithileko ezihlukanisiweko nofana imiphakathi yamamodeli (ama-consortia) kungenza bona kube nokulungiswa okupheleleko, okurhabako nokuphumelelako kwama-PAH la ngokusebenzisa imiphumela yokusebenzisana. Kulokhu kubuyekezwa, sidzimelele eendleleni ezihlukileko zokugaya ukudla nokuhlukahluka, ukwakheka kwezakhi zofuzo nokuhlukahluka, kanye neempendulo zamaseli/ukutjhuguluka kwe-naphthalene kanye namabhaktheriya atjhugulula i-naphthalene. Lokhu kuzokunikela ilwazi le-ekholoji lokusetjenziswa ensimini kanye nokwenza ngcono imihlobo yokulungiswa kwezinto eziphilako.
Ukuthuthukiswa okurhabako kwamabubulo (amakhemikhali we-petroleum, ezolimo, imithi, idayi yezindwangu, izithambiso, njll.) kube nomthelela ekuphumeleleni komnotho wephasi loke kanye namazinga wokuphila ngcono. Ukuthuthukiswa okukhulu lokhu kuphumele ekukhiqizeni inani elikhulu lamakhompawundi wokwenziwa (ama-SOC), asetjenziselwa ukwenza imikhiqizo ehlukileko. Amakhompawundi la wangaphandle nofana ama-SOC afaka hlangana ama-polycyclic aromatic hydrocarbons (ama-PAH), ama-pesticides, ama-herbicides, ama-plasticizer, ama-dayi, ama-pharmaceuticals, ama-organophosphates, ama-flame retardants, ama-volatile organic solvents, njll. imiphumela ema-bioforms ahlukahlukeneko ngokutjhugulula izakhiwo ze-physicochemical kanye nesakhiwo somphakathi (u-Petrie et al., 2015; Bernhardt et al., 2017; Sarkar et al., 2020). Iingcolisa ezinengi ezinamakha zinomthelela onamandla nobhubhisako eensetjenzisweni ezinengi eziphilako/eendaweni ezinengi eziphilako (isib. amadwala wamakhorali, amaqhwa we-Arctic/Antarctic, amachibi weentaba eziphakemeko, iinhlabathi ezijulileko zelwandle, njll.) (Jones 2010; Beyer et al. 2020; Nordborg et al. 2020). Iimfundo ze-geomicrobiology zamva nje zitjengise bona ukubekwa kwezinto eziphilako ezenziweko (isib. izinto ezisilaphazako ezinamakha) kanye nezinto ezivela kizo phezu kwezakhiwo zokwenziwa (indawo eyakhiweko) (isib. iindawo zamagugu wamasiko kanye neenkhumbuzo ezenziwe nge-granite, ilitje, iinkuni kanye nensimbi) kurhabisa ukuwohloka kwazo (Gadd Liu et al. 2017; 2018). Imisebenzi yabantu ingaqinisa begodu yenze kumbi ukuwohloka kwezinto eziphilako kweenkhumbuzo nezakhiwo ngokusilaphazeka komoya nokutjhuguluka kobujamo bezulu (Liu et al. 2020). Iinsilaphazi eziphilako lezi ziphendula nomhwamuko wamanzi emkhathini bese zihlala esakhiweni, okwenza bona izinto zibe nokuwohloka ngokwemvelo nangokwekhemikhali. Ukuwohloka kwezinto eziphilako kwaziwa khulu njengamatjhuguluko angathandekiko ekubukekeni nezakhiweni zezinto ezibangelwa zizinto eziphilako ezithinta ukulondolozwa kwazo (u-Pochon no-Jaton, 1967). Isenzo esingezelelweko sama-microbial (ukugaya ukudla) kwamakhompawundi la kungehlisa ubuqotho besakhiwo, ukusebenza kokulondolozwa kanye nenani lamasiko (Gadd, 2017; Liu et al., 2018). Ngakelinye ihlangothi, kezinye izehlakalo, ukutjhuguluka kwama-microbial nokuphendula ezakhiweni lezi kutholakele bona kuyazuzisa njengombana zakha ama-biofilms namanye ama-crust avikelako aphungula izinga lokubola/ukubola (Martino, 2016). Ngalokho-ke, ukuthuthukiswa kwamaqhinga asebenzako wesikhathi eside wokulondolozwa kweenkhumbuzo zamatje, zensimbi kanye namaplanka kutlhoga ukuzwisisa okuzeleko kweenkambo eziqakathekileko ezibandakanyeka kilenkambo. Nayiqathaniswa neenkambo zemvelo (iinkambo ze-geology, imililo yamahlathi, ukuqhuma kweentabamlilo, ukusabela kweentjalo namabhaktheriya), imisebenzi yabantu ibangela ukukhutjhwa kwamavolumu amakhulu wama-polycyclic aromatic hydrocarbons (ama-PAH) kanye neminye i-organic carbon (OC) eendaweni eziphilako. Ama-PAH amanengi asetjenziswa kwezokulima (izibulala-zinambuzane nezibulala-zinambuzane ezifana ne-DDT, i-atrazine, i-carbaryl, i-pentachlorophenol, njll.), embonini (amafutha ahlanzekileko, idaka lamafutha/imfucuza, amaplastiki avela ku-petroleum, ama-PCB, ama-plasticizer, ama-detergent, ama-infectant, ama-fumigants, ama-preservatives womuntu mathupha), nemikhiqizo yokutlhogomela amakha (ama-sunscreen, ama-infectant, ama-insect repellents kanye nama-polycyclic musks) kanye nezikhali (iziqhumane ezifana ne-2,4,6-TNT) zizinto ezingaba yi-xenobiotics ezingaba nomthelela empilweni yeplanethi (Srogi, 2007; Vamsee-Krishna no-Phale, 2008; Petrie et al., 2015). Irhelo leli linganwetshwa lifake amakhompawundi avela ku-petroleum (amafutha wephethiloli, amafutha wokuthambisa, ama-asphaltenes), ama-bioplastics anesisindo esiphezulu samamolekhuli, kanye nama-ionic liquids (Amde et al., 2015). Ithebula 1 libala izinto ezihlukahlukeneko ezingcolisako ezinamakha nokusetjenziswa kwazo emabubulweni ahlukahlukeneko. Eminyakeni esanda kwedlula, ukukhutjhwa kwabantu kwezinto eziphilako ezivuthako, kanye ne-carbon dioxide neminye imimoya ye-greenhouse, sele ithome ukwanda (u-Dvorak et al., 2017). Kodwana, imithelela eyenziwa babantu idlula khulu leyo yemvelo. Ukungezelela, sithole bona inani lama-SOC lihlala eendaweni ezinengi zebhoduluko begodu likhonjwe njengezinto ezisilaphazako ezivelako ezinemiphumela emimbi ema-biome (Umfanekiso 1). Iinhlangano ezivikela ibhoduluko ezifana ne-United States Environmental Protection Agency (USEPA) zifake ezinengi zezinto ezisilaphazako erhelweni lazo eliqakatheke khulu ngebanga lezakhiwo zazo ezibulala amaseli, ezibulala amajini, ezitjhugulula ukutjhuguluka, kanye nezakhiwo zomdlavuza. Ngalokho-ke, imithetho eqinileko yokulahla kanye namaqhinga asebenzako wokuhlanza/ukususwa kwemfucuza eendaweni ezisilapheleko ziyatlhogeka. Iindlela ezihlukahlukeneko zokulapha ngamakhemikhali ezifana ne-pyrolysis, ukulapha okutjhisako, ukufaka umoya emoyeni, ukulahla iimfesi, ukutjhisa, njll. Ngokwanda kokuqaphela ibhoduluko ephasini loke, iinlwanyane ezincani ezikwazi ukuwohloza iinsilaphazi kanye nezinto ezivela kizo (ezifana ne-halogenated, nitro, alkyl kanye/nofana i-methyl) zidosa ukutjhejwa okukhulu (Fennell et al., 2004; Haritash and Kaushik, 2009; Phale et al., 2002; Sarkar et al., 2020; Sarkar et al., 2020; Sarkar et al., 2002; Schwanemann et al., 2020). Ukusetjenziswa kwama-microorganisms la wodwa nofana ngamasiko ahlanganisiweko (amakoloni) ukususa ukusilaphazeka okunamakha kunezinzuzo malungana nokuphepha kwebhoduluko, iindleko, ukusebenza kuhle, ukusebenza kuhle, nokusimama. Abarhubhululi baphinde bahlole ukuhlanganiswa kweenkambo ze-microbial neendlela ze-electrochemical redox, okutjho i-bioelectrochemical systems (BES), njengethekhnoloji ethembisako yokuhlanza/ukususa ukusilaphazeka (Huang et al., 2011). Ithekhnoloji ye-BES idose ukutjhejwa okukhulu ngebanga lokusebenza kwayo okuphezulu, iindleko eziphasi, ukuphepha kwebhoduluko, ukusebenza ngezinga lokutjhisa legumbi, izinto ezihambisana nezinto eziphilako, nekghono lokubuyisa imikhiqizo eqakathekileko (isib., igezi, amafutha, namakhemikhali) (Pant et al., 2012; Nazari et al., 2020). Ukufika kokulandelana kwe-genome okuphezulu kanye namathulusi/iindlela ze-omics kunikele ngolwazi olutjha olunengi ngokulawulwa kwezakhi zofuzo, i-proteomics, kanye ne-fluxomics yokusabela kweenlwanyana ezihlukahlukeneko eziwohlokako. Ukuhlanganisa amathulusi la nebhayoloji yamasistimu kuthuthukise ukuzwisisa kwethu ukukhethwa nokulungiswa kweendlela eziqothelweko ze-catabolic eenlwaneni ezincani (okutjho, ukuklanywa kwe-metabolic) ukufikelela ukuwohloka kwezinto eziphilako okusebenzako nokuphumelelako. Ukuklama amaqhinga asebenzako wokulungisa izinto eziphilako ngokusebenzisa iinlwanyane ezincani ezifaneleko, kufuze sizwisise amandla we-biochemical, ukuhlukahluka kwe-metabolic, ukwakheka kwezakhi zofuzo, kanye ne-ecology (autoecology/synecology) yama-microorganisms.
Umfanekiso 1. Imithombo neendlela zama-PAHs anamamolekhyuli aphasi ngeendawo ezihlukahlukeneko zebhoduluko kanye nezinto ezihlukahlukeneko ezithinta i-biota. Imigqa edabukileko ijamele ukusebenzisana hlangana kwezinto zemvelo.
Kulokhu kubuyekezwa, sizamile ukufingqa idatha yokuwohloka kwama-PAH alula afana ne-naphthalene kanye nama-naphthalenes afakwe esikhundleni ngamagciwani ahlukahlukeneko ahlanganisa iindlela zokugaya ukudla nokuhlukahluka, ama-enzayimu abandakanyeka ekuwohlokeni, ukwakheka kwamajini/okuqukethwe nokuhlukahluka, iimpendulo zamaseli kanye nezinto ezihlukahlukeneko zokulungiswa kwezinto eziphilako. Ukuzwisisa amazinga we-biochemical kanye nama-molecule kuzokusiza ekutholeni imihlobo efaneleko ye-host kanye nokuragela phambili nobunjiniyela bazo bezakhi zofuzo ukwenzela ukulungisa okuphumelelako kwezinto ezisilaphazako eziqakathekileko. Lokhu kuzokusiza ekuthuthukiseni amaqhinga wokusungulwa kweenhlangano zamabhaktheriya ezikhethekileko zendawo ukwenzela ukulungiswa kwezinto eziphilako okuphumelelako.
Ukuba khona kwenani elikhulu lamakhompawundi anobuthi nayingozi (okwanelisa umthetho we-Huckel 4n + 2π ama-elektroni, n = 1, 2, 3, …) kubeka ingozi ekulu eendaweni ezihlukahlukeneko zebhoduluko ezifana nomoya, ihlabathi, inkunkuma, kanye namanzi angaphezulu nangaphasi komhlabathi (Puglisi et al., 2007). Amakhompawundi la aneendandatho ze-benzene ezilodwa (ezifana ne-monocyclic) nofana ama-benzene amanengi (ama-polycyclic) ahlelwe ngokulandelana, nge-angular nofana i-cluster begodu atjengisa ukuzinza (ukuzinza/ukungazinzi) endaweni ngebanga lamandla aphezulu we-negative resonance kanye nokungasebenzi (ukungasebenzi), okungahlathulula ngokungabi namanzi nobujamo obuphasi. Lokha indandatho ye-aromatic nayithathelwa indawo yi-methyl (-CH3), carboxyl (-COOH), hydroxyl (-OH), nofana i-sulfonate (-HSO3) amaqembu, iyazinza, ibe nokuthandana okunamandla kuma-macromolecules, begodu iyabuthelela eenhlelweni zezinto eziphilako (Seo et al., 2009; Phale et al., 2020). Amanye ama-polycyclic aromatic hydrocarbons aphasi we-molecular weight (LMWAHs), afana ne-naphthalene kanye nezinto ezivela kiyo [i-methylnaphthalene, i-naphthoic acid, i-naphthalenesulfonate, kanye ne-1-naphthyl N-methylcarbamate (carbaryl)], zifakwe erhelweni lezinto eziphilako eziqakatheke khulu yi-US Environmental Agency i-genotoxic, i-mutagenic, kanye/nofana i-carcinogenic (Cerniglia, 1984). Ukukhutjhwa kwalesi sigaba sama-NM-PAHs emvelweni kungaba nomphumela wokubuthelelana kwamakhompawundi la kiwo woke amazinga wokudla, lokho kuthinte ipilo yemvelo (Binkova et al., 2000; Srogi, 2007; Quinn et al., 2009).
Imithombo neendlela zama-PAH ukuya e-biota ikakhulukazi ngokufuduka nokusebenzisana hlangana neengcenye ezihlukahlukeneko zemvelo ezifana nehlabathi, amanzi angaphasi komhlaba, amanzi angaphezulu, iintjalo kanye nomoya (u-Arey no-Atkinson, 2003). Umfanekiso 1 utjengisa ukusebenzisana nokusabalala kwama-PAH ahlukileko anesisindo esiphasi samamolekhyuli eendaweni eziphilako kanye neendlela zawo zokuvezwa kwe-biota/ebantwini. Ama-PAH abekwa phezu kwendawo ngebanga lokusilaphazeka komoya begodu ngokufuduka (ukutjhuguluka) kokukhishwa kweenkoloyi, amagesi we-exhaust webubulo (ukukhiqizwa kwamalahle, ukutjhiswa kanye nokukhiqizwa kwe-coke) nokubekwa kwawo. Imisebenzi yamabubulo efana nokwakhiwa kweengubo zokwenziwa, amadayi namapende; ukulondolozwa kweenkuni; ukusetjenziswa kwerabha; imisebenzi yokwenza isamenti; ukukhiqizwa kwemithi yokubulala iintwala; begodu ukusetjenziswa kwezokulima zimithombo emikhulu yama-PAH eenhlelweni zephasi nezamanzi (u-Bamforth no-Singleton, 2005; u-Wick et al., 2011). Iimfundo zitjengise bona ihlabathi eendaweni ezisemadorobheni, eduze nemigwaqo emikhulu, kanye nasemadorobheni amakhulu zithambekele khulu kuma-polycyclic aromatic hydrocarbons (ama-PAH) ngebanga lokukhishwa kwekhaboni elivela eentjalweni zamandla, ukufuthumala kwezindlu, umthwalo womoya nomgwaqo, kanye nemisebenzi yokwakha (Suman et al., 2016). (2008). Ngokufanako, amazinga we-PAH aphezulu ukuya ku-300 μg/kg abikwe eendaweni eziseduze neendawo zokukhiqiza amalahle emadorobheni amanengi we-US (Kanaly no-Harayama, 2000; Bamforth no-Singleton, 2005). Ihlabathi elivela emadorobheni ahlukahlukeneko we-India njenge-Delhi (Sharma et al., 2008), i-Agra (Dubey et al., 2014), i-Mumbai (Kulkarni no-Venkataraman, 2000) kanye ne-Visakhapatnam (Kulkarni et al., 2014) ibikwe bona ine-PAH ephezulu. Amakhompawundi we-aromatic adonswa lula eenhlayithini zehlabathi, izinto eziphilako kanye namaminerali wobumba, lokho kwenza bona kube ziinqhema ezikulu zekhabhoni eendaweni eziphilako (u-Srogi, 2007; Peng et al., 2008). Imithombo emikhulu yama-PAH eendaweni ezihlala emanzini yizulu (izulu elimanzi/elomileko kanye nomhwamuko wamanzi), ukugeleza kwamanzi emadorobheni, ukukhishwa kwamanzi angcolileko, ukugcwaliswa kwamanzi angaphasi komhlaba njll. (Srogi, 2007). Kulinganiselwa bona ama-PAH angaba ma-80% eendaweni eziphilako zaselwandle avela emvula, ukutjhinga kwehlabathi, nokulahlwa kwemfucuza (Motelay-Massei et al., 2006; Srogi, 2007). Ukugxila okukhulu kwama-PAH emanzini angaphezulu nofana ukugeleza okuvela eendaweni zokulahla iimfesi eziqinileko ekugcineni kuvuza emanzini angaphasi komhlaba, okwenza bona kube yingozi ekulu epilweni yomphakathi ngombana abantu abangaphezu kwama-70% eSewula neSewulapumalanga ye-Asia basela amanzi angaphasi komhlaba (Duttagupta et al., 2019). Irhubhululo lakamuva elenziwa ngu-Duttagupta et al. (2020). Amaphetheni wokusetjenziswa kwehlabathi ahlukileko kanye nokukhutjhwa kwamanzi ngaphasi komhlaba okungezelelweko kuthathwa njengezinto eziqakathekileko ezilawula ukuthuthwa okujameleko (ukutjhinga) kwama-PAH wesisindo esiphasi samamolekhyuli ngaphasi kwehlabathi. Ukugeleza kwamanzi wezokulima, ukulahlwa kwamanzi angcolileko kamasipala newebubulo, kanye nokulahlwa kwemfucuza eqinileko/imfucuza kutholakele bona kuthinteka ngama-PAHs emifuleni kanye neenhlabathi ezingaphasi kwehlabathi. Imvula emkhathini iragela phambili nokusilaphazeka kwe-PAH. Ukugxila okukhulu kwama-PAH kanye nama-alkyl derivatives wawo (ama-51 woke) kubikwe emilanjeni/eendaweni zamanzi ephasini loke, njenge-Fraser River, i-Louan River, i-Denso River, i-Missouri River, i-Anacostia River, i-Ebro River, kanye ne-Delaware River (Yunker et al., 2002; Motelay-Massei et al., 2006; Li et al., 2006; 2010; Amoako et al., 2011; Kim et al., 2018). Eenhlabathini ze-Ganges River basin, i-naphthalene ne-phenanthrene kwatholakala bona ziqakatheke khulu (zitholwe kuma-70% wamasampula) (Duttagupta et al., 2019). Ngaphezu kwalokho, iimfundo zitjengise bona ukufakwa kwe-chlorine emanzini wokusela kungarholela ekwakhiweni kwama-PAH anobuthi ane-oksijini ne-chlorine (uManoli no-Samara, 1999). Ama-PAH abuthelela emasiriyeli, iinthelo nemirorho ngebanga lokuthathwa ziintjalo ezivela ehlabathini elingcolileko, amanzi angaphasi kwehlabathi kanye nemvula (Fismes et al., 2002). Iinlwanyana ezinengi eziphila emanzini ezifana neemfesi, ama-mussel, ama-clams kanye nama-shrimp angcoliswe ma-PAH ngokudla ukudla okungcolileko namanzi welwandle, kanye nangokusebenzisa amathitjhu nesikhumba (u-Mackay no-Fraser, 2000). Iindlela zokupheka/zokusebenza ezifana nokupheka, ukuthosa, ukubhema, ukuthosa, ukomisa, ukubhaka nokupheka ngamalahle nakho kungaholela ekutheni kube nama-PAH amanengi khulu ekudleni. Lokhu kuyame khulu ekukhetheni izinto zokubhema, okuqukethwe kwe-phenolic/aromatic hydrocarbon, ikambiso yokupheka, umhlobo we-heater, okuqukethwe komswakama, ukunikelwa kwe-oksijini kanye nezinga lokutjhisa (Guillén et al., 2000; Gomes et al., 2013). Ama-polycyclic aromatic hydrocarbons (ama-PAH) nawo atholakele ebisi ngamazinga ahlukileko (0.75–2.1 mg/L) (Girelli et al., 2014). Ukubuthelela kwama-PAH la ekudleni nakho kuya ngobujamo be-physicochemical bokudla, ngesikhathi imiphumela yawo enobuthi ihlobene nemisebenzi yomzimba, umsebenzi wokugaya ukudla, ukumuncwa, ukusabalalisa nokusabalala komzimba (Mechini et al., 2011).
Ubuthi nemiphumela emimbi yama-polycyclic aromatic hydrocarbons (PAHs) sele kwaziwa isikhathi eside (Cherniglia, 1984). Ama-polycyclic aromatic hydrocarbons wesisindo esiphasi (ama-LMW-PAH) (amasongo amabili ukuya kwamathathu) angahlanganisa ama-macromolecules ahlukahlukeneko afana ne-DNA, i-RNA namaphrotheyini begodu abanga umdlavuza (u-Santarelli et al., 2008). Ngebanga lobujamo bazo bokuthanda amanzi, zihlukaniswe ziinqhema zamafutha. Ebantwini, ama-cytochrome P450 monooxygenases enza ama-PAH abe ma-epoxide, amanye wawo aphendula khulu (isib., i-baediol epoxide) begodu angadosela ekutjhugulukeni kwamaseli ajayelekileko abe ngama-malignant (Marston et al., 2001). Ukungezelela, imikhiqizo yokutjhuguluka yama-PAH afana nama-quinones, ama-phenols, ama-epoxides, ama-diols, njll. anobuthi ukudlula amakhompawundi womzali. Amanye ama-PAH kanye nama-intermediates wawo wokugaya ukudla angathinta amahomoni nama-enzyme ahlukahlukeneko ekugabeni ukudla, ngaleyo ndlela kuthinte kumbi ukukhula, uhlelo lwezinzwa oluphakathi, uhlelo lokuzala nokuzivikela komzimba (Swetha no-Phale, 2005; Vamsee-Krishna et al., 2006; Oostingh et al., 2008). Ukuvezwa kwesikhathi esifitjhani kuma-PAH wesisindo esiphasi kubikwe bona kubangela ukukhubazeka kokusebenza kwamaphaphu kanye ne-thrombosis ebantwini abanesifuba begodu kwandisa ubungozi bomdlavuza wesikhumba, wamaphaphu, wesinye kanye nomdlavuza wesisu (Olsson et al., 2010; Diggs et al., 2011). Iimfundo zeenlwana zibuye zitjengise bona ukuvezwa kwe-PAH kungaba nemiphumela emimbi ekusebenzeni nokuthuthuka kokuzala begodu kungabanga ukulimala kwe-cataract, ukulimala kwezinso nesibindi, kanye ne-jaundice. Imikhiqizo ehlukileko ye-PAH efana nama-diols, ama-epoxides, ama-quinones kanye nama-free radicals (ama-cations) atjengiswe bona akha ama-DNA adducts. Ama-adduct azinzileko atjengiswe bona atjhugulula imitjhini yokuphindaphinda i-DNA, lokha ama-adduct angazinzileko angakhipha i-DNA (khulukhulu ibe yi-adenine begodu kesinye isikhathi ibe yi-guanine); kokubili kungakhiqiza amaphutha arholela ekuguqukeni kwemihlobo (Schweigert et al. 2001). Phezu kwalokho, ama-quinones (benzo-/pan-) angakhiqiza imihlobo ye-oksijini esebenzako (ROS), okubangela umonakalo obulalako ku-DNA namanye ama-macromolecules, lokho kuthinte ukusebenza/ukuphila kwezicubu (Ewa no-Danuta 2017). Ukuvezwa isikhathi eside emazingeni aphasi we-pyrene, biphenyl kanye ne-naphthalene kubikwe bona kubanga umdlavuza eenlwaneni ezihlolwako (u-Diggs et al. 2012). Ngebanga lobuthi bawo obubulalako, ukuhlanza/ukususwa kwama-PAH la eendaweni ezithintekileko/ezisilapheleko kuyinto eqakathekileko.
Iindlela ezihlukahlukeneko zomzimba namakhemikhali zisetjenziselwe ukususa ama-PAH eendaweni/eendaweni ezisilapheleko. Iinqubo ezifana nokutjhisa, ukukhipha i-chlorine, ukukhipha i-UV oksijini, ukuqinisa, nokukhipha isisombululo zinobubi obunengi, okufaka hlangana ukwakheka kwemikhiqizo enobuthi, ubudisi bendlela, iindaba zokuphepha nezokulawula, ukusebenza kuhle okuphasi, kanye neendleko eziphezulu. Kodwana, ukuwohloka kwezinto eziphilako (okubizwa ngokuthi yi-bioremediation) yindlela ethembisako efaka hlangana ukusetjenziswa kwezinto eziphilako ezincani ngendlela yamasiko ahlanzekileko nofana amakoloni. Nayiqathaniswa neendlela eziphathekako nezamakhemikhali, ikambiso le ayilimazi ibhoduluko, ayihlaseli, ayibizi, begodu iyasimama. Ukulungiswa kwezinto eziphilako kungenziwa endaweni ethintekako (in situ) nofana endaweni elungiselelwe ngokukhethekileko (ex situ) begodu ngalokho kuthathwa njengendlela yokulungiswa esimeme ukudlula iindlela ezijayelekileko zomzimba nezamakhemikhali (Juhasz no-Naidu, 2000; Andreoni no-Gianfreda, 2007; Megharaj et al., 201; Phale et al., 2020; Phale et al., 2020; Sarkar et al., 2020).
Ukuzwisisa amagadango wokugaya ukudla kwama-microbial abandakanyeka ekuwohlokeni kwezinto ezingcolisako ezinamakha kunemithelela emikhulu yezesayensi nezomnotho ekusimameni kwemvelo nebhoduluko. I-2.1×1018 yamagremu wekhabhoni (C) agcinwe eenhlabathini kanye namakhompawundi we-organic (okutjho, amafutha, irhasi yemvelo, namalahle, okutjho, amafutha we-fossil) ephasini loke, okwenza igalelo elikhulu emjikelezweni wekhabhoni wephasi loke. Kodwana, ukukhiqizwa kweemboni okurhabako, ukukhiqizwa kwamafutha, nemisebenzi yabantu kuqeda amadamu wekhabhoni we-lithospheric, kukhupha i-5.5×1015 g yekhabhoni (njengezinto ezisilaphazako) emmoyeni qobe mnyaka (Gonzalez-Gaya et al., 2019). Inengi lekhabhoni ephilako ingena eendaweni eziphilako ephasini nezamanzi ngokusebenzisa ukutjhinga, ukuthuthwa, nokugeleza. Ukungezelela, izinto ezingcolisako ezitjha ezenziwe ngamafutha, ezifana namaplastiki, amaplastiki kanye namaplastiki (ama-phthalates nama-isomer wawo), angcolisa khulu iinlwana zaselwandle, zehlabathi kanye nezemvelo zamanzi kanye ne-biota yazo, lokho kwenza bona kube nobungozi bezulu bephasi loke. Imihlobo ehlukileko yama-microplastics, ama-nanoplastics, ama-fragments weplastiki kanye nemikhiqizo yawo enobuthi evela ku-polyethylene terephthalate (PET) ibuthelele eLwandle lwe-Pacific hlangana kwe-North America ne-Southeast Asia, yakha “i-Great Pacific Garbage Patch”, elimaza ukuphila kwaselwandle (Newell et al., 20202). Iimfundo zezesayensi zifakazele bona akukghonakali ukususa izinto ezisilaphazako/imfucuza nganoma ngiziphi iindlela eziphathekako nofana zamakhemikhali. Kulomongo, iinlwanyana ezincani eziwusizo khulu ngilezo ezikghona ukutjhugulula izinto ezisilaphazako zibe yi-carbon dioxide, amandla wamakhemikhali nezinye izinto ezingenabuthi ezigcina zingena kwezinye iinkambo zokujikeleza kwezakhamzimba (H, O, N, S, P, Fe, njll.). Ngalokho, ukuzwisisa i-ecophysiology yama-microbial ye-aromatic pollutant mineralization kanye nokulawulwa kwayo kwebhoduluko kuqakathekile ekuhloleni umjikelezo wekhabhoni we-microbial, isabelomali sekhabhoni kanye nobungozi bezulu besikhathi esizako. Njengombana kunetlhogeko ephuthumako yokususa amakhompawundi anjalo emvelweni, amabubulo ahlukahlukeneko we-eco agxile ebuchwephesheni obuhlanzekileko sele avele. Ngenye indlela, ukuqakathekiswa kwemfucuza yamabubulo/amakhemikhali wemfucuza abuthelelwe eendaweni zemvelo (okutjho indlela yokusebenzisa imfucuza ukuya emnothweni) kuthathwa njengenye yeensika zomnotho ojikelezako kanye nemigomo yentuthuko esimemeko (u-Close et al., 2012). Ngalokho-ke, ukuzwisisa ubujamo bokugaya ukudla, ubujamo be-enzymatic kanye nobujamo bezakhi zofuzo zalezi ezingaba khona zokuwohloka kuqakatheke khulu ekususweni okuphumelelako nokulungiswa kwezinto eziphilako ezingcolisako.
Hlangana nezinto ezinengi ezisilaphazako, sitjheja khulu ama-PAH anesisindo esiphasi afana ne-naphthalene kanye nama-naphthalenes athathelwe indawo. Amakhompawundi la ziingcenye eziqakathekileko zamafutha avela ku-petroleum, amadayi weentjhila, imikhiqizo yabathengi, iinbulalantwala (ama-mothballs nama-insect repellents), ama-plasticizer nama-tannins begodu ngalokho asabalalele eendaweni ezinengi (u-Preuss et al., 2003). Imibiko yakamuva iveza ukubuthelela kwe-naphthalene eenhlabathini ze-aquifer, emanzini angaphasi kwehlabathi kanye nehlabathi engaphasi kwehlabathi, eendaweni ze-vadose kanye nemifula, okusikisela ukubuthelela kwayo kwezinto eziphilako emvelweni (Duttagupta et al., 2019, 2020). Ithebula 2 lifingqa ubujamo be-physicochemical, ukusetjenziswa kanye nemiphumela yezamaphilo ye-naphthalene nezinto ezivela kiyo. Nayiqathaniswa namanye ama-PAH anesisindo esiphezulu, i-naphthalene kanye nezinto ezivela kiyo azithandi amanzi, zincibilika khulu emanzini begodu zisabalele khulu eendaweni eziphilako, njeke zivame ukusetjenziswa njengeendlela zokufunda ukugaya ukudla, izakhi zofuzo kanye nokuhlukahluka kokugaya ukudla kwama-PAH. Inani elikhulu lama-microorganisms akghona ukugaya i-naphthalene kanye nezinto ezivela kiyo, begodu ilwazi elipheleleko liyatholakala ngeendlela zazo zokugaya ukudla, ama-enzyme kanye nezinto ezilawulako (Mallick et al., 2011; Phale et al., 2019, 2020). Ukungezelela, i-naphthalene nezinto ezivela kiyo zikhethwe njengeenhlanganisela zokuthoma zokuhlola ukusilaphazeka kwebhoduluko ngebanga lobunengi bazo nokutholakala kwazo. I-Ejensi yokuVikelwa kweBhoduluko ye-US ilinganisela bona amazinga aphakathi we-naphthalene angama-5.19 μg nge-cubic meter evela emsini wegwayi, khulukhulu ukusuka ekutjhiseni okungakapheleli, begodu angama-7.8 ukuya ku-46 μg avela emsini we-sidestream, ngesikhathi ukuvezwa ku-creosote ne-naphthalene ku-100 ukuya ku-1000, phezulu (Preus et al. 2003). I-Naphthalene ikakhulukazi itholakale inobuthi bokuphefumula obuqondene nemihlobo, isifunda, kanye nobulili kanye nokubanga umdlavuza. Ngokuya ngeemfundo zezilwane, i-International Agency for Research on Cancer (IARC) ihlukanise i-naphthalene njenge-“carcinogen ebantwini engenzeka” (Isiqhema 2B)1. Ukuvezwa kuma-naphthalenes athathelwe indawo, khulukhulu ngokuphefumula nofana ngokuphathwa ngomlomo, kubangela ukulimala kwezicubu zamaphaphu begodu kwandisa izehlakalo zezimila zamaphaphu emagundvwaneni namagundwaneni (Ihlelo le-National Toxicology Program 2). Imiphumela ebukhali ifaka hlangana ukucasuka, ukuhlanza, ubuhlungu besisu, ukurhuda, ukuphathwa yihloko, ukudideka, ukujuluka okukhulu, umkhuhlane, i-tachycardia, njll. Ngakelinye ihlangothi, i-carbamate insecticide ebanzi i-carbaryl (1-naphthyl N-methylcarbamate) ibikwe bona iyingozi eenlwaneni ezihlala emanzini ezihlala emanzini, nabantu begodu kutjengiswe bona ivimbela i-acetylcholinesterase ebangela ukukhubazeka (Smulders et al., 2003; Bulen and Distel, 2011). Ngalokho-ke, ukuzwisisa iindlela zokuwohloka kwama-microbial, ukulawulwa kwezakhi zofuzo, ukusabela kwe-enzymatic kanye namaseli kuqakathekile ekuthuthukiseni amaqhinga wokulungisa izinto eziphilako eendaweni ezisilapheleko.
Ithebula 2. Ilwazi elinabileko ngezakhiwo ze-physicochemical, ukusetjenziswa, iindlela zokukhomba kanye namalwelwe ahlotjaniswa ne-naphthalene nezinto ezivela kiyo.
Eendaweni ezisilapheleko, izinto ezingcolisako ezithanda amanzi nezithanda amafutha zingabangela imiphumela ehlukileko yamaseli e-microbiome (umphakathi), njengokutjhuguluka kokugeleza kwe-membrane, ukungena kwe-membrane, ukuvuvuka kwe-lipid bilayer, ukuphazamiseka kokudluliswa kwamandla (i-electron transport chain/proton motive force), kanye nomsebenzi wamaphrotheyini ahlotjaniswa ne-membrane (Sikke et al. 1995). Ukungezelela, ezinye izinto eziphakathi ezincibilikako ezifana nama-catechols nama-quinones zikhiqiza imihlobo ye-oksijini esebenzako (ROS) begodu zakha ama-adducts nge-DNA namaphrotheyini (Penning et al., 1999). Ngalokho-ke, ubunengi bamakhompawundi anjalo eendaweni eziphilako bubeka umfutho okhethiweko emiphakathini yama-microbial bona ibe ziinsetjenziswa ezisebenza kuhle emazingeni ahlukahlukeneko womzimba, okufaka hlangana ukuthathwa/ukuthuthwa, ukutjhuguluka kwangaphakathi kwamaseli, ukuhlanganiswa/ukusetjenziswa, nokuhlukaniswa.
Ukusesha kwe-Ribosomal Database Project-II (RDP-II) kuveze bona inani lemihlobo yamabhaktheriya ayi-926 yahlukaniswa eendaweni ezihlukahlukeneko nofana amasiko wokunothisa angcoliswe yi-naphthalene nofana izinto ezivela kiyo. Isiqhema se-Proteobacteria besinenani eliphezulu labajameli (n = 755), kulandele i-Firmicutes (52), i-Bacteroidetes (43), i-Actinobacteria (39), i-Tenericutes (10), kanye nama-bacteria angakahlukaniswa (8) (Umfanekiso 2). Abajameleli be-γ-Proteobacteria (Pseudomonadales kanye ne-Xanthomonadales) babusa woke amaqembu we-Gram-negative ane-G+C ephezulu (54%), ngesikhathi i-Clostridiales ne-Bacillales (30%) bekumaqembu we-Gram-positive ane-G+C ephasi. Ama-Pseudomonas (inani eliphezulu, imihlobo ema-338) kwabikwa bona akghona ukuwohloza i-naphthalene kanye nama-methyl derivatives wayo eendaweni ezihlukahlukeneko ezisilapheleko (itala yamalahle, i-petroleum, i-oli ehlwengileko, udaka, ukuchitheka kwamafutha, amanzi angcolileko, i-organic waste kanye nama-landfill) kanye nama-ecosystems angapheliko (amanzi wemilambo, amanzi angaphasi kwehlabathi, amanzi angaphasi kwehlabathi) (Umfanekiso 2). Ngaphezu kwalokho, iimfundo zokunothisa nokuhlaziywa kwe-metagenomic kwezinye zezifunda kuveze bona imihlobo ye-Legionella ne-Clostridium engakakhuliswa ingaba namandla wokuwohloka, okutjengisa isidingo sokukhula kwamagciwane la ukufunda iindlela ezitjha nokuhlukahluka kwe-metabolic.
Umfanekiso 2. Ukuhlukahluka kwe-taxonomic kanye nokusabalala kwemvelo kwabajameleko bamagciwane eendaweni ezingcoliswe yi-naphthalene kanye ne-naphthalene derivatives.
Hlangana nama-microorganisms ahlukahlukeneko anamakha we-hydrocarbon, amanengi akghona ukuwohloka i-naphthalene njengomthombo owodwa wekhabhoni namandla. Ukulandelana kwezehlakalo ezibandakanyeka ekusebenzeni kwe-naphthalene kuchaziwe nge-Pseudomonas sp. (iinhlobo: NCIB 9816-4, G7, AK-5, PMD-1 kanye ne-CSV86), i-Pseudomonas stutzeri AN10, i-Pseudomonas fluorescens PC20 nezinye iinhlobo (ND6 kanye ne-AS1) (Mahajan et al., 1994; Resnick et al., 1996; Anweer et al., 2000; al., 2003; Dennis and Zylstra, 2004; Sota et al., 2006; Ukugaya ukudla kuthonywa yi-multicomponent dioxygenase [i-naphthalene dioxygenase (NDO), i-ring hydroxylating dioxygenase] ekhuthaza ukukhiqizwa kwe-oksijini kwenye ye-ring ye-aromatic ye-naphthale i-substrate, etjhugulula i-naphthalene ibe yi-cis-naphthalenediol (Umfanekiso 3). I-2-hydroxychromene-2-carboxylic acid i-enzymatic cis-trans isomerization ikhiqiza i-trans-o-hydroxybenzylidenepyruvate, ehlukaniswa yi-hydratase aldolase ibe yi-salicylic aldehyde ne-pyruvate. Indlela. Ngaphezu kwalokho, i-NAD+-dependent salicylaldehyde itjhugulula i-salicylaldehyde esigabeni lesi ibizwa ngokuthi "yindlela ephezulu" yokuwohloka kwe-naphthalene. hamburgii 2, ukuwohloka kwe-naphthalene kuthoma nge-naphthalene 2,3-dioxygenase ukwakha i-2,3-dihydroxynaphthalene (Annweiler et al., 2000).
Umfanekiso 3. Iindlela ze-naphthalene, i-methylnaphthalene, i-naphthoic acid, kanye nokuwohloka kwe-carbaryl. Inomboro eziyindilinga zijamele ama-enzayimu anesibopho sokutjhugulula ngokulandelana kwe-naphthalene nezinto ezivela kiyo zibe mikhiqizo elandelako. 1 — i-naphthalene dioxygenase (NDO); 2, cis-dihydrodiol dehydrogenase; 3, 1,2-dihydroxynaphthalene dioxygenase; 4, 2-hydroxychromene-2-carboxylic acid isomerase; 5, i-trans-O-hydroxybenzylidendepyruvate hydratase aldolase; 6, i-salicylaldehyde dehydrogenase; 7, i-salicylate 1-hydroxylase; 8, i-catechol 2,3-dioxygenase (C23DO); 9, 2-hydroxymuconate semialdehyde dehydrogenase; 10, 2-oxopent-4-enoate hydratase; 11, 4-hydroxy-2-oxopentanoate aldolase; 12, i-acetaldehyde dehydrogenase; 13, catechol-1,2-dioxygenase (C12DO); 14, i-muconate cycloisomerase; 15, i-muconolactone delta-isomerase; 16, β-ketoadipatenollactone hydrolase; 17, β-ketoadipate succinyl-CoA transferase; 18, β-ketoadipate-CoA thiolase; 19, i-succinyl-CoA: i-acetyl-CoA i-succinyltransferase; 20, i-salicylate 5-hydroxylase; 21 – i-gentisate 1,2-dioxygenase (GDO); 22, i-maleylpyruvate isomerase; 23, i-fumarylpyruvate hydrolase; 24, i-methylnaphthalene hydroxylase (NDO); 25, i-hydroxymethylnaphthalene dehydrogenase; 26, i-naphthaldehyde dehydrogenase; 27, 3-formylsalicylic acid oxidase; 28, i-hydroxyisophthalate decarboxylase; 29, i-carbaryl hydrolase (CH); 30, 1-naphthol-2-hydroxylase.
Ngokuya ngezinto eziphilako kanye nokwakheka kwazo kwezakhi zofuzo, i-salicylic acid ephumelako iragela phambili nokusetjenziswa ngendlela ye-catechol kusetjenziswa i-salicylate 1-hydroxylase (S1H) nofana ngendlela ye-gentisate kusetjenziswa i-salicylate 5-hydroxylase (S5H) (Umfanekiso 3). Njengombana i-salicylic acid iyinto ephakathi khulu ekusebenzeni kwe-naphthalene (indlela ephezulu), amagadango avela ku-salicylic acid ukuya e-TCA intermediate avamise ukubizwa ngokuthi yi-lower pathway, begodu amajini ahlelwe abe yi-operon eyodwa. Kuvamile ukubona bona amajini we-operon yendlela ephezulu (nah) kanye ne-operon yendlela ephasi (sal) alawulwa zizinto ezilawulako ezijayelekileko; isibonelo, i-NahR kanye ne-salicylic acid zisebenza njengeenthombe, zivumela zombili i-operons bona zisebenzise i-naphthalene ngokupheleleko (Phale et al., 2019, 2020).
Ukungezelela, i-catechol ihlukaniswa ngokujikelezako ibe yi-2-hydroxymuconate semialdehyde ngendlela ye-meta nge-catechol 2,3-dioxygenase (C23DO) (Yen et al., 1988) bese iphinde ihlatjhwe yi-2-hydroxymuconate semialdehyde hydrolase ukwakha i-2-hydroxymuconate semialdehyde, 24-24-dioxygenac. I-2-hydroxypent-2,4-dienoate itjhugululwa ibe yi-pyruvate ne-acetaldehyde nge-hydratase (2-oxopent-4-enoate hydratase) kanye ne-aldolase (4-hydroxy-2-oxopentanoate aldolase) bese ingena emzileni wekhabhoni (Umfanekiso 3). Ngenye indlela, i-catechol ihlukaniswa ibe yi-cis, cis-muconate ngendlela ye-ortho nge-catechol 1,2-oxygenase (C12DO). I-muconate cycloisomerase, i-muconolactone isomerase, kanye ne-β-ketoadipate-nollactone hydrolase itjhugulula i-cis, cis-muconate ibe yi-3-oxoadipate, engena endleleni yekhabhoni ephakathi nge-succinyl-CoA ne-acetyl-CoA (Nozaki et al., 1968) (Umfanekiso 33).
Endleleni ye-gentisate (2,5-dihydroxybenzoate), indandatho ye-aromatic ihlukaniswa yi-gentisate 1,2-dioxygenase (GDO) ukwakha i-maleylpyruvate. Umkhiqizo lo ungatjhugululwa ube yi-pyruvate ne-malate, nofana ungatjhugululwa ube yi-fumarylpyruvate, engatjhugululwa ube yi-pyruvate ne-fumarate (Larkin no-Day, 1986). Ukukhethwa kwenye indlela sele kubonakele emagciwaneni we-Gram-negative kanye nama-Gram-positive emazingeni we-biochemical newezakhi zofuzo (Morawski et al., 1997; Whyte et al., 1997). Amagciwani we-gram-negative (i-Pseudomonas) akhetha ukusebenzisa i-salicylic acid, okuyi-inducer ye-naphthalene metabolism, ukuyikhipha i-catechol ngokusebenzisa i-salicylate 1-hydroxylase (Gibson no-Subramanian, 1984). Ngakelinye ihlangothi, emagciwaneni we-Gram-positive (i-Rhodococcus), i-salicylate 5-hydroxylase itjhugulula i-salicylic acid ibe yi-gentisic acid, lokha i-salicylic acid ayinawo umphumela wokuthoma ekutlolweni kwamajini we-naphthalene (Grund et al., 1992) (Umfanekiso 3).
Kubikwe bona imihlobo efana ne-Pseudomonas CSV86, i-Oceanobacterium NCE312, i-Marinhomonas naphthotrophicus, i-Sphingomonas paucimobilis 2322, i-Vibrio cyclotrophus, i-Pseudomonas fluorescens LP6a, i-Pseudomonas kanye ne-Mycobacterium ye-moncinethynom dimethylnaphthalene (Dean-Raymond no-Bartha, 1975; Cane no-Williams, 1982; Mahajan et al., 1994; Dutta et al., 1998; Hedlund et al., 1999). Hlangana nazo, indlela yokuwohloka kwe-1-methylnaphthalene ne-2-methylnaphthalene ye-Pseudomonas sp. I-CSV86 ifundwe kuhle emazingeni we-biochemical kanye ne-enzymatic (Mahajan et al., 1994). I-1-Methylnaphthalene itjhugululwa ngeendlela ezimbili. Kokuthoma, indandatho ye-aromatic i-hydroxylated (indandatho engakafakwa esikhundleni se-methylnaphthalene) ukwakha i-cis-1,2-dihydroxy-1,2-dihydro-8-methylnaphthalene, ephinde i-oxidized ibe yi-methyl salicylate ne-methylcatechol, bese ingena emzileni wekhabhoni ophakathi ngemva kokuvela kwendandatho ye-clecle (Umfanekiso 3). Indlela le ibizwa ngokuthi "indlela yomthombo wekhabhoni". Endleleni yesibili "yokukhipha ubuthi", isiqhema se-methyl singafakwa nge-hydroxylated yi-NDO ukwakha i-1-hydroxymethylnaphthalene, ephinde i-oxidized ibe yi-1-naphthoic acid bese ikhutjhwa ibe yi-culture medium njengomkhiqizo ongapheliko. Iimfundo zitjengise bona umhlobo we-CSV86 awukwazi ukukhula ku-1- kanye ne-2-naphthoic acid njengomthombo wekhabhoni namandla, okuqinisekisa indlela yayo yokukhipha ubuthi (Mahajan et al., 1994; Basu et al., 2003). Ku-2-methylnaphthalene, isiqhema se-methyl sithola i-hydroxylase nge-hydroxylase ukwakha i-2-hydroxymethylnaphthalene. Ukungezelela, indandatho engakathathelwa indawo yeringi ye-naphthalene yenza i-ring hydroxylation ukwakha i-dihydrodiol, e-oxidized ibe yi-4-hydroxymethylcatechol ngokulandelana kwe-enzyme-catalyzed reactions bese ingena endleleni yekhabhoni ephakathi ngendlela ye-meta-ring cleavage. Ngokufanako, i-S. paucimobilis 2322 kwabikwa bona isebenzisa i-NDO ukwenza i-hydroxylate i-2-methylnaphthalene, ephinde i-oxidized ukwakha i-methyl salicylate ne-methylcatechol (Dutta et al., 1998).
Ama-esidi we-naphthoic (athathelwe indawo/angakathathelwa indawo) zizinto ezikhiqiza ubuthi/zokutjhugulula izinto eziphilako ezakhiwe ngesikhathi sokuwohloka kwe-methylnaphthalene, i-phenanthrene kanye ne-anthracene bese zikhutjhwa zibe sesikhungweni esisetjenzisiweko. Kubikwe bona i-Stenotrophomonas maltophilia CSV89 ehlukanisiweko yehlabathi ikghona ukutjhugulula i-1-naphthoic acid njengomthombo wekhabhoni (Phale et al., 1995). Ukugaya ukudla kuthoma ngokuhlukaniswa kwendandatho ye-aromatic ukwakha i-1,2-dihydroxy-8-carboxynaphthalene. I-diol ephumelako iyatjhugululwa ibe yi-catechol nge-2-hydroxy-3-carboxybenzylidenepyruvate, i-3-formylsalicylic acid, i-2-hydroxyisophthalic acid kanye ne-salicylic acid bese ingena endleleni yekhabhoni ephakathi ngendlela ye-meta-ring cleavage (Umfanekiso 3).
I-Carbaryl sibulala-zinambuzane se-naphthyl carbamate. Solo kwaba yi-Green Revolution e-India ngeminyaka yabo-1970, ukusetjenziswa kwamakhemikhali namakhemikhali wokubulala iinlwanyana kuholele ekwandeni kokukhishwa kwe-polycyclic aromatic hydrocarbon (PAH) evela emithonjeni yezokulima (Pingali, 2012; Duttagupta et al., 2020). Kulinganiselwa bona ama-55% (amahekthara ama-85,722,000) wendawo yokutjala e-India iphathwa ngamakhemikhali wokubulala iinlwanyana. Eminyakeni emihlanu edlulileko (2015 ukuya ku-2020), umkhakha wezokulima we-India usebenzise isilinganiso samathani ama-55,000 ukuya ku-60,000 wemithi yokubulala iinlwanyana qobe mnyaka (UmNyango wezamaBambiswano neNhlalakahle yabalimi, uMnyango wezokuLima, uRhulumende we-India, uRhoboyi 2020). Emathafeni we-Gangetic asenyakatho nephakathi (amazwe anenani eliphezulu labantu kanye nokuminyana kwabantu), ukusetjenziswa kwemithi yokubulala iinlwanyana eentjalweni kusabalele, begodu imithi yokubulala iinlwanyana inengi khulu. I-Carbaryl (1-naphthyl-N-methylcarbamate) mhlobo obanzi, onobuthi obuphakathi ukuya kobuthi obukhulu be-carbamate esetjenziswa kwezokulima kwe-India ngezinga eliphakathi lamathani ali-100 ukuya keli-110. Ivamise ukuthengiswa ngaphasi kwebizo lokurhweba elithi Sevin begodu isetjenziselwa ukulawula iinambuzane (ama-aphids, iintuthwane zomlilo, ama-fleas, ama-mites, iingwegwe kanye nezinye iinlwanyana ezinengi zangaphandle) ezithinta iintjalo ezihlukahlukeneko (ummbila, isoya, ikoteni, iinthelo nemirorho). Ezinye iinlwana ezincani ezifana ne-Pseudomonas (NCIB 12042, 12043, C4, C5, C6, C7, Pseudomonas putida XWY-1), i-Rhodococcus (NCIB 12038), i-Sphingobacterium spp. (CF06), Burkholderia (C3), Micrococcus kanye ne-Arthrobacter nazo zingasetjenziswa ukulawula ezinye iinambuzane. Kubikwe bona i-RC100 ingaqeda i-carbaryl (Larkin no-Day, 1986; Chapalamadugu no-Chaudhry, 1991; Hayatsu et al., 1999; Swetha no-Phale, 2005; Trivedi et al., 2017). Indlela yokuwohloka kwe-carbaryl sele ifundwe khulu emazingeni we-biochemical, we-enzymatic kanye newezakhi zofuzo ehlabathini elihlukanisiweko le-Pseudomonas sp. Iinhlobo ze-C4, C5 kanye ne-C6 (Swetha no-Phale, 2005; Trivedi et al., 2016) (Umfanekiso 3). Indlela yokugaya ukudla ithoma ngokuhlukaniswa kwe-ester bond nge-carbaryl hydrolase (CH) ukwakha i-1-naphthol, i-methylamine kanye ne-carbon dioxide. I-1-naphthol itjhugululwa ibe yi-1,2-dihydroxynaphthalene nge-1-naphthol hydroxylase (1-NH), eragela phambili nokutjhugululwa ngendlela ye-carbon ephakathi nge-salicylate ne-gentisate. Amanye amabhaktheriya ahlahla i-carbaryl abikwe bona ayayitjhugulula ibe yi-salicylic acid ngokuhlukaniswa kwe-catechol ortho ring (Larkin no-Day, 1986; Chapalamadugu no-Chaudhry, 1991). Ngokuphawulekako, amagciwane ahlahla i-naphthalene atjhugulula i-salicylic acid nge-catechol, kuthi amagciwane ahlahla i-carbaryl akhetha ukutjhugulula i-salicylic acid ngendlela ye-gentisate.
I-naphthalenesulfonic acid/disulfonic acid kanye ne-naphthylaminesulfonic acid derivatives zingasetjenziswa njengezinto eziphakathi ekukhiqizeni amadayi we-azo, ama-ejenti wokuthambisa, ama-dispersants, njll. Nanyana amakhompawundi la anobuthi obuphasi ebantwini, ukuhlolwa kwe-cytotoxicity kutjengise bona ayabulala iimfesi, i-daphim kanye ne-algaenia, et. 1994). Abajameleli bomhlobo we-Pseudomonas (ama-strain A3, C22) babikwe bona bathoma ukugaya ukudla ngokusebenzisa i-double hydroxylation ye-aromatic ring ene-sulfonic acid group ukwakha i-dihydrodiol, ephinde itjhugululwe ibe yi-1,2-dihydroxynaphthalene ngokuhlukaniswa kweqembu le-sulfite (BB et al., 1918). I-1,2-dihydroxynaphthalene ephumelako yenziwa ngendlela ye-naphthalene, okutjho bona, indlela ye-catechol nofana ye-gentisate (Umfanekiso 4). Kutjengisiwe bona i-aminonaphthalenesulfonic acid kanye ne-hydroxynaphthalenesulfonic acid zingatjhabalaliswa ngokupheleleko ziinhlangano ezihlangeneko zamabhaktheriya ezineendlela ezihambisanako (Nortemann et al., 1986). Kutjengiswe bona ilunga elilodwa le-consortium likhipha i-aminonaphthalenesulfonic acid nofana i-hydroxynaphthalenesulfonic acid nge-1,2-dioxygenation, ngesikhathi i-aminosalicylate nofana i-hydroxysalicylate ikhutjhwa ngaphakathi kwe-culture medium njenge-metabolite engapheliko begodu ngemva kwalokho ithathwe ngamanye amalunga we-consortium. I-Naphthalenedisulfonic acid ine-polar kodwana ayikwazi ukubola kuhle begodu ingatjhugululwa ngeendlela ezihlukileko. Ukukhipha i-sulfurization kokuthoma kwenzeka ngesikhathi sokukhetha i-dihydroxylation ye-aromatic ring kanye nesiqhema se-sulfonic acid; ukususwa kwesibili kwenzeka ngesikhathi sokukhiqizwa kwe-5-sulfosalicylic acid nge-salicylic acid 5-hydroxylase ukwakha i-gentisic acid, engena endleleni ye-carbon ephakathi (u-Brilon et al., 1981) (Umfanekiso 4). Ama-enzayimu anesibopho sokuwohloka kwe-naphthalene nawo anesibopho sokusebenza kwe-naphthalene sulfonate (Brilon et al., 1981; Keck et al., 2006).
Umfanekiso 4. Iindlela zokugaya ukudla zokuwohloka kwe-naphthalene sulfonate. Inomboro engaphakathi kwemibuthano ijamele ama-enzayimu anesibopho sokusebenza kwe-naphthyl sulfonate, afana/afana nama-enzayimu achazwe ku-FIG. 3.
Ama-PAH wesisindo esiphasi samamolekhyuli (ama-LMW-PAH) ayanciphiswa, awathandi amanzi begodu awancibiliki kuhle, begodu ngalokho awavunyelwa ukuwohloka/ukuwohloka kwemvelo. Nanyana kunjalo, iinlwanyana eziphilako eziphilako zikghona ukuyenza i-oksijini ngokumunya i-oksijini yamamolekhyuli (O2). Ama-enzyme la ikakhulukazi angesigaba sama-oxidoreductases begodu angenza ukusabela okuhlukahlukeneko okufana ne-aromatic ring hydroxylation (mono- nofana dihydroxylation), dehydrogenation kanye nokuhlukaniswa kwe-aromatic ring. Imikhiqizo etholakala kilokhu kuphendula isesigabeni esiphezulu se-oksijini begodu itjhugululwa lula ngendlela ye-carbon ephakathi (Phale et al., 2020). Ama-enzayimu asendleleni yokuwohloka abikwe bona angathonywa. Ukusebenza kwama-enzyme la kuphasi khulu nofana akutjhejwa lokha amaseli nakakhuliswa emithonjeni elula yekhabhoni efana ne-glucose nofana ama-organic acid. Ithebula 3 lifingqa ama-enzayimu ahlukahlukeneko (ama-oksigenasi, ama-hydrolase, ama-dehydrogenase, ama-oxidase, njll.) abandakanyeka ekusebenzeni kwe-naphthalene nezinto ezivela kiyo.
Ithebula 3. Iimfanelo zamakhemikhali wezinto eziphilako zama-enzayimu anesibopho sokuwohloka kwe-naphthalene nezinto ezivela kiyo.
Iimfundo ze-radioisotope (18O2) zitjengise bona ukufakwa kwe-molecule O2 emaringini we-aromatic ngama-oxygenases kuligadango eliqakatheke khulu ekusebenzeni ukuwohloka kwe-biodegradation yekhompawundi (Hayaishi et al., 1955; Mason et al., 1955). Ukufakwa kwe-athomu eyodwa ye-oksijini (O) evela ku-oksijini yamamolekhyuli (O2) ngaphakathi kwe-substrate kuthonywa ngama-monooxygenases wangaphakathi nofana wangaphandle (abizwa nangokuthi ma-hydroxylases). Enye i-athomu ye-oksijini yehliswa yaba mamanzi. I-exogenous monooxygenases yehlisa i-flavin nge-NADH nofana i-NADPH, kuthi kuma-endomonooxygenases i-flavin yehliswa yi-substrate. Ubujamo be-hydroxylation buphumela ekuhlukahlukeni ekwakhiweni komkhiqizo. Ukwenza isibonelo, i-salicylate 1-hydroxylase i-hydroxylate i-salicylic acid endaweni ye-C1, yakha i-catechol. Ngakelinye ihlangothi, i-multicomponent salicylate 5-hydroxylase (equkethe i-reductase, i-ferredoxin, kanye nama-oxygenase subunits) i-hydroxylate i-salicylic acid endaweni ye-C5, yakha i-gentisic acid (Yamamoto et al., 1965).
Ama-dioxygenases afaka ama-athomu amabili we-O2 ngaphakathi kwe-substrate. Ngokuya ngemikhiqizo eyakhiweko, ihlukaniswe yaba yi-ring hydroxylating dioxygenases kanye ne-ring cleaving dioxygenases. Ama-ring hydroxylating dioxygenases atjhugulula ama-aromatic substrates abe ma-cis-dihydrodiols (isib., i-naphthalene) begodu asabalalele hlangana namabhaktheriya. Bekube nje, kutjengisiwe bona iinlwana ezine-ring hydroxylating dioxygenases zikghona ukukhula emithonjeni ehlukileko yekhabhoni, begodu ama-enzyme la ahlukaniswe njenge-NDO (naphthalene), toluene dioxygenase (TDO, toluene), kanye ne-biphenyl dioxygenase (BPDO, biphenyl). Kokubili i-NDO ne-BPDO zingakhuthaza ukukhiqizwa kwe-oksijini kabili kanye ne-side chain hydroxylation yama-hydrocarbons ahlukahlukeneko we-polycyclic aromatic (i-toluene, i-nitrotoluene, i-xylene, i-ethylbenzene, i-naphthalene, i-biphenyl, i-fluorene, i-indole, i-methylnaphthalene, i-naphthalene, i-phenthalene, i-acetophenone, njll.) (Boyd no-Sheldrake, 1998; Phale et al., 2020). I-NDO lihlelo elineengcenye ezinengi eliqukethe i-oxidoreductase, i-ferredoxin, kanye ne-oksigenase enendawo esebenzako (u-Gibson no-Subramanian, 1984; u-Resnick et al., 1996). Iyunithi yokukhuthaza ye-NDO ineyunithi ekulu ye-α kanye neyunithi encani ye-β ehlelwe ngendlela ye-α3β3. I-NDO ingeyomndeni omkhulu wama-oxygenases begodu i-α-subunit yayo inendawo ye-Rieske [2Fe-2S] kanye ne-mononuclear non-heme iron, okunquma ubujamo be-substrate ye-NDO (Parales et al., 1998). Ngokuvamileko, emjikelezweni owodwa we-catalytic, ama-elektroni amabili avela ekwehliseni i-pyridine nucleotide adluliselwa ku-Fe(II) ion endaweni esebenzako nge-reductase, i-ferredoxin kanye nendawo ye-Rieske. Iinlinganiso ezinciphisako zivuselela i-oksijini yamamolekhyuli, okuyimfuneko yokuthoma ukukhiqizwa kwe-substrate (Ferraro et al., 2005). Bekube nje, ma-NDO ambalwa kwaphela ahlanjululwe begodu ahlanjululwe ngokunabileko ukusuka emihlobeni ehlukileko begodu ukulawulwa kwezakhi zofuzo kweendlela ezithintekako ekuwohlokeni kwe-naphthalene kufundwe ngokunabileko (Resnick et al., 1996; Parales et al., 1998; Karlsson et al., 2003). Ama-ring-cleaving dioxygenases (ama-enzyme we-endo- nofana we-ortho-ring-cleaving kanye nama-enzyme we-exodiol- nofana we-meta-ring-cleaving) asebenza kumakhompawundi we-hydroxylated aromatic. Ukwenza isibonelo, i-ortho-ring-cleaving dioxygenase yi-catechol-1,2-dioxygenase, kuthi i-meta-ring-cleaving dioxygenase yi-catechol-2,3-dioxygenase (Kojima et al., 1961; Nozaki et al., 1968). Ngaphezu kwama-oxygenase ahlukahlukeneko, kune-dehydrogenase ehlukahlukeneko enesibopho sokukhipha i-hydrogenation yama-aromatic dihydrodiols, ama-alcohols nama-aldehydes nokusebenzisa i-NAD+/NADP+ njengama-electron acceptors, okungamanye wama-enzyme aqakathekileko abandakanyeka ekusebenzeni kwe-metabolism (Gibson no-Subramanian, 1984; Shaw no-Harayama, 1900; Faraya et al., et al., et al., et al., et al., et al. 2020).
Ama-enzayimu afana nama-hydrolases (ama-esterases, ama-amidases) mhlobo wesibili oqakathekileko wama-enzayimu asebenzisa amanzi ukuhlukanisa ama-covalent bonds begodu atjengise ukukhetheka okubanzi kwe-substrate. I-Carbaryl hydrolase namanye ama-hydrolase athathwa njengeengcenye ze-periplasm (transmembrane) emalungwini we-Gram-negative bacteria (Kamini et al., 2018). I-Carbaryl ine-amide ne-ester linkage; ngalokho-ke, ingahlanganiswa yi-esterase nofana yi-amidase ukwakha i-1-naphthol. I-Carbaryl ku-Rhizobium rhizobium strain AC10023 kanye ne-Arthrobacter strain RC100 kubikwe bona isebenza njenge-esterase ne-amidase, ngokulandelana. I-Carbaryl ku-Arthrobacter strain RC100 nayo isebenza njenge-amidase. I-RC100 itjengiswe bona yenza bona i-hydrolyze i-N-methylcarbamate class insecticides ezine ezifana ne-carbaryl, methomyl, mefenamic acid kanye ne-XMC (Hayaatsu et al., 2001). Kwabikwa bona i-CH ku-Pseudomonas sp. I-C5pp ingasebenza ku-carbaryl (100% yomsebenzi) kanye ne-1-naphthyl acetate (36% yomsebenzi), kodwana ingasi ku-1-naphthylacetamide, okutjengisa bona yi-esterase (Trivedi et al., 2016).
Iimfundo ze-biochemical, amaphetheni wokulawulwa kwama-enzyme, nokuhlaziywa kwezakhi zofuzo kutjengise bona amajini wokuwohloka kwe-naphthalene anamayunithi amabili alawulako nofana "ama-operons": nah ("indlela ephezulu", eguqula i-naphthalene ibe yi-salicylic acid) kanye ne-sal ("indlela eya phasi", eguqula ibe yi-salicylic acid ephakathi). I-Salicylic acid kanye nama-analogues wayo angasebenza njenge-inducers (u-Shamsuzzaman no-Barnsley, 1974). Nakukhona i-glucose nofana ama-organic acid, i-operon iyagandeleleka. Umfanekiso 5 utjengisa ukuhleleka okupheleleko kwezakhi zofuzo zokuwohloka kwe-naphthalene (ngefomu le-operon). Iinhlobo ezinengi ezibizwako/amafomu we-nah gene (ndo/pah/dox) sele zichaziwe begodu zitholakale zinokulandelana okuphezulu (90%) hlangana nazo zoke iinhlobo ze-Pseudomonas (Abbasian et al., 2016). Amajini wendlela ye-naphthalene ephezulu bekahlelwe ngokulandelana kokuvumelana njengombana kutjengiswe kuMfanekiso 5A. Elinye ijini, i-nahQ, nalo kwabikwa bona libandakanyeka ekusebenzeni kwe-naphthalene begodu belivamise ukutholakala hlangana ne-nahC ne-nahE, kodwana umsebenzi walo wamambala usazokucaciswa. Ngokufanako, ijini ye-nahY, enesibopho se-naphthalene-sensitive chemotaxis, yatholakala ekupheleni kwe-nah operon kwamanye amalunga. Ku-Ralstonia sp., isakhi sofuzo se-U2 esikhoda i-glutathione S-transferase (gsh) satholakala siphakathi kwe-nahAa ne-nahAb kodwana azange sithinte ubujamo bokusetjenziswa kwe-naphthalene (Zylstra et al., 1997).
Umfanekiso 5. Ukuhleleka kwezakhi zofuzo nokuhlukahluka okubonwe ngesikhathi sokuwohloka kwe-naphthalene hlangana nemihlobo yamabhaktheriya; (A) Indlela ye-naphthalene ephezulu, ukutjhuguluka kwe-naphthalene ukuya ku-salicylic acid; (B) Indlela ye-naphthalene ephasi, i-salicylic acid nge-catechol ukuya endleleni yekhabhoni ephakathi; (C) i-salicylic acid nge-gentisate ukuya endleleni yekhabhoni ephakathi.
Indlela "ephasi" (i-sal operon) ivamise ukuba ne-nahGTHINLMOKJ begodu itjhugulula i-salicylate ibe yi-pyruvate kanye ne-acetaldehyde ngendlela ye-catechol metaring cleavage. Ijini le-nahG (elikhoda i-salicylate hydroxylase) latholakala ligcinwe ekupheleni kwe-operon (Umfanekiso 5B). Nayiqathaniswa neminye imihlobo ebhidliza i-naphthalene, ku-P. putida CSV86 ama-operon we-nah ne-sal ahlangene begodu ahlobene khulu (ama-7.5 kb). Kwamanye amagciwani we-Gram-negative, afana ne-Ralstonia sp. U2, Polaromonas naphthalenivorans CJ2, kanye ne-P. putida AK5, i-naphthalene itjhugululwa njenge-metabolite yekhabhoni ephakathi ngendlela ye-gentisate (ngendlela ye-sgp/nag operon). Ikhasethi yezakhi zofuzo ivamise ukuvezwa ngefomu le-nagAaGHAbAcAdBFCQEDJI, lapho i-nagR (ekhoda umlawuli womhlobo we-LysR) itholakala ekupheleni okuphezulu (Umfanekiso 5C).
I-Carbaryl ingena emjikelezweni wekhabhoni ophakathi ngokusebenza kwe-1-naphthol, 1,2-dihydroxynaphthalene, i-salicylic acid, kanye ne-gentisic acid (Umfanekiso 3). Ngokuya ngeemfundo zezakhi zofuzo neze-metabolic, kuphakanyisiwe bona indlela le ihlukaniswe ibe “phezulu” (ukutjhugululwa kwe-carbaryl ibe yi-salicylic acid), “phakathi” (ukutjhuguluka kwe-salicylic acid ibe yi-gentisic acid), kanye “nezansi” (ukutjhuguluka kwe-gentisic acid ibe ziindlela eziphakathi zekhabhoni) (Sing et al., 2013). Ukuhlaziywa kwe-genomic ye-C5pp (supercontig A, 76.3 kb) kuveze bona isakhi sofuzo se-mcbACBDEF sibandakanyeka ekuguqulweni kwe-carbaryl ibe yi-salicylic acid, kulandelwe yi-mcbIJKL ekuguqulweni kwe-salicylic acid ibe yi-gentisic acid, kanye ne-mcbOQP ekuguqulweni kwe-central genmaratisic acid kanye nama-carbonitis acid ( pyruvate, Trivedi et al., 2016) (Umfanekiso 6).
Kubikwe bona ama-enzyme abandakanyeka ekuwohlokeni kwama-aromatic hydrocarbons (okufaka hlangana i-naphthalene ne-salicylic acid) angabangelwa ziinhlanganisela ezihambisanako begodu avinjelwe mithombo yekhabhoni elula efana ne-glucose nofana ama-organic acid (Shingler, 2003; Phale et al., 2019, 2020). Hlangana neendlela ezihlukahlukeneko zokugaya ukudla ze-naphthalene nezinto ezivela kiyo, iimpawu zokulawula ze-naphthalene ne-carbaryl zifundwe ngezinga elithileko. Nge-naphthalene, amajini womabili weendlela eziya phezulu nezaphasi alawulwa yi-NahR, umlawuli omuhle we-LysR-type trans-acting. Iyatlhogeka ekungenisweni kwejini ye-nah nge-salicylic acid kanye nokuvezwa kwayo okusezingeni eliphezulu (u-Yen no-Gunsalus, 1982). Ukudlula lapho, iimfundo zitjengise bona i-integrative host factor (IHF) kanye ne-XylR (sigma 54-dependent transcriptional regulator) nazo ziqakathekile ekusebenzeni kwe-transcriptional yamajini ku-naphthalene metabolism (Ramos et al., 1997). Iimfundo zitjengise bona ama-enzyme we-catechol meta-ring opening pathway, okutjho i-catechol 2,3-dioxygenase, akhuthazwa ebukhoneni be-naphthalene kanye/nofana i-salicylic acid (Basu et al., 2006). Iimfundo zitjengise bona ama-enzyme we-catechol ortho-ring opening pathway, okutjho i-catechol 1,2-dioxygenase, akhuthazwa ebukhoneni be-benzoic acid ne-cis, cis-muconate (Parsek et al., 1994; Tover et al., 2001).
Emhlobeni we-C5pp, amajini amahlanu, i-mcbG, i-mcbH, i-mcbN, i-mcbR kanye ne-mcbS, ikhoda iinlawuli ezivela emndenini we-LysR/TetR weenlawuli zokutlola ezilawula ukuwohloka kwe-carbaryl. Ijini elifanako mcbG latholakala lihlobene khulu nomlawuli we-LysR-type PhnS (58% we-amino acid identity) obandakanyeka ekusebenzeni kwe-phenanthrene ku-Burkholderia RP00725 (Trivedi et al., 2016). Ijini le-mcbH latholakala libandakanyeka endleleni ephakathi (ukutjhugululwa kwe-salicylic acid ibe yi-gentisic acid) begodu linge-LysR-type transcriptional regulator i-NagR/DntR/NahR ku-Pseudomonas ne-Burkholderia. Amalunga womndeni lo kwabikwa bona abona i-salicylic acid njenge-molecule ethileko yokwenza amajini wokuwohloka. Ngakelinye ihlangothi, amajini amathathu, i-mcbN, i-mcbR kanye ne-mcbS, engabalawuli bomhlobo we-LysR kanye ne-TetR, akhonjwa endleleni eya phasi (ama-metabolites wendlela ye-gentisate-central carbon).
Ema-prokaryotes, iinkambo zokudlulisa amajini (ukutholwa, ukutjhugululwa, nofana ukudluliswa) ngokusebenzisa ama-plasmid, ama-transposon, ama-prophages, ama-genomic islands, kanye nama-integrative conjugative elements (ICE) zizimbangela ezikulu zobuplastiki kuma-genomes wamabhaktheriya, okurholela ekuzuzeni nofana ekulahlekelweni kwemisebenzi/iimfanelo ezithileko. Ivumela amagciwani bona atjhuguluke msinyana ebujameni obuhlukahlukeneko bebhoduluko, okunikela iinzuzo ezitjhugulukako zokugaya ukudla emzimbeni, njengokuwohloka kwamakhompawundi anamakha. Amatjhuguluko we-metabolic avamise ukufezwa ngokulungiswa okuhle kwama-operons wokuwohloka, iindlela zawo zokulawula, kanye nobujamo bama-enzyme, okwenza kube lula ukuwohloka kwemihlobo ebanzi yamakhompawundi we-aromatic (Nojiri et al., 2004; Phale et al., 2019, 2020). Amakhasethi wezakhi zofuzo zokuwohloka kwe-naphthalene atholakele bona atholakala eentweni ezihlukahlukeneko ezihambako ezifana nama-plasmid (ahlanganisiweko nalawo angahlanganisiweko), ama-transposons, ama-genomes, ama-ICEs, kanye nokuhlanganiswa kwemihlobo ehlukileko yebhaktheriya (Umfanekiso 5). Ku-Pseudomonas G7, i-nah ne-sal operons ye-plasmid NAH7 itlolwe ngendlela efanako begodu yingcenye ye-transposon engakalungi edinga i-transposase Tn4653 ukobana ihlanganiswe (Sota et al., 2006). Ku-Pseudomonas strain NCIB9816-4, ijini latholakala ku-plasmid ye-pDTG1 njengama-operon amabili (alinganiselwa ku-15 kb ukusuka komunye nomunye) ebegade atlolwe ngendlela ehlukileko (u-Dennis no-Zylstra, 2004). Ku-Pseudomonas putida strain AK5, i-non-conjugative plasmid pAK5 ikhoda i-enzayimu enesibopho sokuwohloka kwe-naphthalene ngendlela ye-gentisate (Izmalkova et al., 2013). Ku-Pseudomonas strain PMD-1, i-nah operon itholakala ku-chromosome, kuthi i-sal operon itholakala ku-conjugative plasmid pMWD-1 (Zuniga et al., 1981). Kodwana, ku-Pseudomonas stutzeri AN10, woke amajini wokuwohloka kwe-naphthalene (ama-nah kanye nama-sal operon) atholakala ku-chromosome begodu kucatshangelwa bona aqatjhwe ngokusebenzisa izenzakalo zokudluliselwa, ukuhlanganiswa kabutjha, nokuhlela kabutjha (Bosch et al., 2000). Ku-Pseudomonas sp. I-CSV86, i-nah ne-sal operons zitholakala ku-genome ngendlela ye-ICE (ICECSV86). Isakhiwo sivikelwe yi-tRNAGly kulandele ukuphindaphinda okuqondileko okutjengisa iindawo zokuhlanganiswa/zokunamathela (i-attR ne-attL) kanye ne-integrase efana ne-phage etholakala emaphethelweni womabili we-tRNAGly, ngalokho isakhiwo sifana ne-ICEclc element (ICEclcB13 ku-Pseudomonas knackmusii ukuwohloka kwe-chlorocatechol). Kubikwe bona amajini ku-ICE angadluliselwa ngokuhlanganiswa ngefrekhwensi yokudlulisa ephasi khulu (10-8), ngaleyo ndlela kudluliselwe izakhiwo zokuwohloka komamukeli (Basu no-Phale, 2008; Phale et al., 2019).
Inengi lamajini anesibopho sokuwohloka kwe-carbaryl asema-plasmid. I-Arthrobacter sp. I-RC100 inama-plasmid amathathu (pRC1, pRC2 kanye ne-pRC300) lapho ama-plasmid amabili ahlangeneko, i-pRC1 ne-pRC2, akhoda ama-enzayimu atjhugulula i-carbaryl ibe yi-gentisate. Ngakelinye ihlangothi, ama-enzyme abandakanyeka ekutjhugululeni i-gentisate ibe zii-carbon metabolites eziphakathi zitholakala ku-chromosome (Hayaatsu et al., 1999). Ibhaktheriya yomhlobo we-Rhizobium. Umhlobo we-AC100, osetjenziselwa ukutjhugulula i-carbaryl ibe yi-1-naphthol, une-plasmid pAC200, ephethe isakhi sofuzo se-cehA esikhoda i-CH njengengcenye ye-Tnceh transposon ebhodwe ziinhlelo ezifana ne-insertion element (istA ne-istB) (Hashimoto et al., 2002). Ku-Sphingomonas strain CF06, ijini lokuwohloka kwe-carbaryl kukholelwa bona likhona kuma-plasmid amahlanu: pCF01, pCF02, pCF03, pCF04, kanye ne-pCF05. Ukufana kwe-DNA yama-plasmid la kuphezulu, okutjengisa ukuba khona komcimbi wokuphindaphindwa kwezakhi zofuzo (Feng et al., 1997). Ku-carbaryl-degrading symbiont eyakhiwe ziinhlobo ezimbili ze-Pseudomonas, i-strain 50581 iqukethe i-conjugative plasmid pCD1 (50 kb) ekhoda isakhi se-mcd carbaryl hydrolase gene, kuthi i-conjugative plasmid ku-strain 50552 ikhode i-1-naphhal-engrading engrameme (C Chaudhry, 1991). Ku-Achromobacter strain WM111, ijini le-mcd furadan hydrolase litholakala ku-100 kb plasmid (pPDL11). Ijini le itjengiswe bona ikhona kuma-plasmid ahlukileko (100, 105, 115 nofana 124 kb) emagciwaneni ahlukileko avela eendaweni ezihlukahlukeneko (Parekh et al., 1995). Ku-Pseudomonas sp. I-C5pp, woke amajini anesibopho sokuwohloka kwe-carbaryl atholakala ku-genome ethatha i-76.3 kb yokulandelana (Trivedi et al., 2016). Ukuhlaziywa kwe-genome (6.15 Mb) kuveze ubukhona bama-MGE ama-42 nama-GEI ama-36, lapho ama-MGE ali-17 bekatholakala ku-supercontig A (76.3 kb) nge-avareji ye-asymmetric G+C (54–60 mol%), okusikisela izehlakalo zokudluliswa kwezakhi zofuzo ezingaba khona (Trivedi et al., 2016). I-P. putida XWY-1 itjengisa ukuhleleka okufanako kwamajini we-carbaryl-degrading, kodwana amajini la ase-plasmid (Zhu et al., 2019).
Ngaphezu kokusebenza kuhle kwe-metabolic emazingeni we-biochemical kanye ne-genomic, ama-microorganisms nawo atjengisa ezinye izakhiwo nofana iimpendulo ezifana ne-chemotaxis, izakhiwo zokutjhugulula ubujamo bamaseli, ukuhlukaniswa, ukusetjenziswa okukhethwako, ukukhiqizwa kwe-biosurfactant, njll., okuzisiza bona zisebenzise kuhle izinto ezingcolisako ezinamakha eendaweni ezisilapheleko (Umfanekiso 7).
Umfanekiso 7. Amaqhinga ahlukileko wokuphendula kwamaseli wamagciwane alungele ukuwohloka kwe-hydrocarbon ukuwohloka okuphumelelako kwamakhompawundi wezinto ezisilaphazako.
Iimpendulo ze-chemotactic zithathwa njengezinto ezikhuphula ukuwohloka kwezinto ezingcolisako eziphilako eendaweni ezingcolileko ezihlukahlukeneko. (2002) watjengisa bona i-chemotaxis ye-Pseudomonas sp. I-G7 ukuya ku-naphthalene ikhuphule izinga lokuwohloka kwe-naphthalene eenhlelweni zamanzi. Umhlobo we-wild-type G7 wehlisa i-naphthalene msinya khulu ukudlula umhlobo omutjha onganawo ama-chemotaxis. Iprotheyini ye-NahY (ama-amino acid ama-538 ane-membrane topology) yatholakala bona itlolwe ngokubambisana namajini wendlela ye-metacleavage ku-NAH7 plasmid, begodu njengama-chemotaxis transducers, iphrotheyini le ibonakala isebenza njenge-chemoreceptor yokuwohloka kwe-naphthalene (u-Grimm no-Harwood 1997). Olunye ucwaningo olwenziwa ngu-Hansel et al. (2009) watjengisa bona iphrotheyini ine-chemotactic, kodwana izinga lokuwohloka kwayo liphezulu. (2011). Abarhubhululi basebenzise ukuziphatha kwamakhemikhali ukwenza ama-microbes azokukhuphula izinga lokuwohloka. Iimfundo zitjengise bona iindlela ze-chemosensory nazo zilawula eminye imisebenzi yamaseli njengokuhlukana kwamaseli, ukulawulwa komjikelezo wamaseli, kanye nokwakheka kwe-biofilm, ngaleyindlela kusize ukulawula izinga lokuwohloka. Kodwana, ukusebenzisa ubujamo lobu (i-chemotaxis) ukuwohloka okuphumelelako kuphazanyiswa ziinqabo ezinengi. Iinqabo ezikulu ngilezi: (a) ama-receptor ahlukileko abona amakhompawundi/ama-ligand afanako; (b) ukuba khona kwezinye iinthombe, okutjho, i-tropism enamandla; (c) umehluko oqakathekileko wokulandelana kwemikhakha yemizwa yomndeni ofanako we-receptor; kanye (d) nokutlhogeka kwelwazi ngamaphrotheyini amakhulu we-bacteria (Ortega et al., 2017; Martin-Mora et al., 2018). Kwesinye isikhathi, ukuwohloka kwama-hydrocarbons anamakha kukhiqiza ama-metabolites/ama-intermediates amanengi, okungaba yi-chemotactic kweqembu elilodwa lamabhaktheriya kodwana kube yinto enyanyekako kwabanye, okwenza bona ikambiso ibe budisi. Ukukhomba ukusebenzisana kwama-ligand (ama-aromatic hydrocarbons) nama-receptors wamakhemikhali, sakha amaphrotheyini we-sensor ahlanganisiweko (PcaY, McfR, kanye ne-NahY) ngokuhlanganisa ama-sensor kanye nama-signling domains we-Pseudomonas putida ne-Escherichia coli, okuqothe ama-receptors we-aromatic acids, i-TCA intermediates, naphthalene, ngokulandelana (Luthale et al., et al. 2019).
Ngaphasi kwethonya le-naphthalene namanye ama-polycyclic aromatic hydrocarbons (ama-PAH), ukwakheka kwe-bacteria membrane kanye nobuqotho bama-microorganisms kutjhuguluka khulu. Iimfundo zitjengise bona i-naphthalene iphazamisa ukusebenzisana kweketango le-acyl ngokusebenzisana kwamanzi, ngaleyindlela kwandisa ukuvuvuka nokugeleza kwe-membrane (Sikkema et al., 1995). Ukulwisana nomphumela omumbi lo, amagciwani alawula ukugeleza kwe-membrane ngokutjhugulula isilinganiso nokwakheka kwamafutha hlangana nama-iso/anteiso branched-chain fatty acids kanye nokwenza ama-cis-unsaturated fatty acids abe ma-trans-isomers ahambelanako (Heipieper no-de Bont, 1994). Ku-Pseudomonas stutzeri ekhuliswe nge-naphthalene, isilinganiso samafutha agcwele ukuya ku-unsaturated sakhula ukusuka ku-1.1 ukuya ku-2.1, kuthi ku-Pseudomonas JS150 isilinganiso lesi sakhuphuka ukusuka ku-7.5 ukuya ku-12.0 (Mrozik et al., 2004). Lokha nakhuliswa ku-naphthalene, amaseli we-Achromobacter KAs 3–5 atjengisa ukubuthelelana kwamaseli azungeze amakristalu we-naphthalene kanye nokwehla kwetjhaji yeseli (kusuka ku--22.5 ukuya ku--2.5 mV) okukhambisana nokuncibilika kwe-cytoplasmic kanye nokuvuvuka, okutjengisa amatjhuguluko esakhiweni seseli kanye nezakhiwo zeseli (Mohapa et al., 2019). Nanyana ukutjhuguluka kwamaseli/wephasi kuhlotjaniswa ngqo nokuthathwa okungcono kwezinto ezingcolisako ezinamakha, amaqhinga wobunjiniyela bezinto eziphilako afanelekako awakalungiswa ngokupheleleko. Ukutjhugulula ukwakheka kwamaseli akukavami ukusetjenziswa ukuthuthukisa iinkambo zezinto eziphilako (Volke no-Nikel, 2018). Ukususwa kwamajini athinta ukwahlukana kwamaseli kubangela amatjhuguluko ekubunjweni kwamaseli. Ukususwa kwamajini athinta ukwahlukana kwamaseli kubangela amatjhuguluko ekubunjweni kwamaseli. Ku-Bacillus subtilis, iphrotheyini ye-sell septum i-SepF itjengiswe bona iyabandakanyeka ekwakhiweni kwe-septum begodu iyatlhogeka emagadangweni alandelako wokuhlukaniswa kwamaseli, kodwana akusilo ijini eliqakathekileko. Ukususwa kwamajini akhoda ama-peptide glycan hydrolases ku-Bacillus subtilis kwabangela ukukhula kwamaseli, ukwanda kwezinga lokukhula elithileko, kanye nokuthuthukisa amandla wokukhiqiza ama-enzyme (Cui et al., 2018).
Ukuhlukaniswa kwendlela yokuwohloka kwe-carbaryl kuphakanyisiwe ukufikelela ukuwohloka okuphumelelako kwemihlobo ye-Pseudomonas C5pp ne-C7 (Kamini et al., 2018). Kuphakanyiswa bona i-carbaryl ithuthwa iye esikhaleni se-periplasmic nge-outer membrane septum kanye/nofana nge-diffusible porins. I-CH yi-enzyme ye-periplasmic ekhuthaza ukuhlukaniswa kwe-carbaryl ibe yi-1-naphthol, okuzinzileko, okungathandi amanzi begodu okunobuthi. I-CH isendaweni ye-periplasm begodu ine-affinity ephasi ye-carbaryl, ngaleyo ndlela ilawula ukwakheka kwe-1-naphthol, ngaleyo ndlela ivimbele ukubuthelela kwayo emaseli begodu yehlise ubuthi bayo emaseli (Kamini et al., 2018). I-1-naphthol ephumelako ithunyelwa ku-cytoplasm ngaphetjheya kwe-membrane yangaphakathi ngokuhlukaniswa kanye/nofana ngokurhatjheka, bese i-hydroxylated ibe yi-1,2-dihydroxynaphthalene nge-enzyme ephezulu ye-1NH ukuragela phambili nokusebenza kwe-metabolism endleleni ye-carbon ephakathi.
Nanyana ama-microorganisms anamandla wezakhi zofuzo kanye nokugaya ukudla ukuwohloka kwemithombo yekhabhoni ye-xenobiotic, isakhiwo sokusetjenziswa kwawo (okutjho, ukusetjenziswa okukhethekileko kwemithombo yekhabhoni elula kunaleyo eyinkimbinkimbi) kusithiyo esikhulu ekuwohlokeni kwezinto eziphilako. Ukuba khona nokusetjenziswa kwemithombo yekhabhoni elula kwehlisa amajini akhoda ama-enzayimu ahlasela imithombo yekhabhoni eyinkimbinkimbi/engakakhethwa njengama-PAH. Isibonelo esifundwe kuhle kukobana lokha i-glucose ne-lactose nayiphakelwa ku-Escherichia coli, i-glucose isetjenziswa kuhle ukudlula i-lactose (u-Jacob no-Monod, 1965). I-Pseudomonas ibikwe bona yehlisa ama-PAH ahlukahlukeneko kanye namakhompawundi we-xenobiotic njengemithombo yekhabhoni. Ukulandelana kokusetjenziswa komthombo wekhabhoni ku-Pseudomonas ku-organic acids > glucose > amakhompawundi we-aromatic (Hylemon and Phibbs, 1972; Collier et al., 1996). Kodwana, kunokuhlukileko. Ngokukarisako, i-Pseudomonas sp. I-CSV86 itjengisa isakhiwo esihlukileko esisebenzisa khulu ama-hydrocarbons anamakha (i-benzoic acid, i-naphthalene, njll.) kunokobana isebenzise i-glucose begodu isebenzisa ama-hydrocarbons anamakha nama-organic acid (Basu et al., 2006). Kulebhaktheriya, amajini wokuwohloka nokuthuthwa kwama-hydrocarbons anamakha awalawulwa phasi ngitjho nanyana kunomthombo wesibili wekhabhoni ofana ne-glucose nofana ama-organic acid. Lokha nayikhuliswa ngaphakathi kwe-glucose kanye nama-aromatic hydrocarbons, kwatjhejwa bona amajini wokuthutha i-glucose nokugaya ukudla bekalawulwa phasi, ama-aromatic hydrocarbons asetjenziswa esigabeni sokuthoma se-log, begodu i-glucose yasetjenziswa esigabeni sesibili se-log (Basu et al., 2006; Choudhary et al., 2017). Ngakelinye ihlangothi, ukuba khona kwama-asidi we-organic akuzange kuthinte ukuvezwa kwe-aromatic hydrocarbon metabolism, ngalokho-ke ibhaktheriya le ilindeleke bona ibe mhlobo okhethiweko weemfundo zokuwohloka kwezinto eziphilako (Phale et al., 2020).
Kuyaziwa bona ukutjhuguluka kwe-hydrocarbon kungabangela ukugandeleleka kwe-oxidative kanye nokulawulwa kwama-enzyme we-antioxidant eenlwaneni ezincani. Ukuwohloka kwe-naphthalene okungasebenziko kokubili emaseli wesigaba esijameleko kanye nalapho kukhona amakhompawundi anobuthi kurholela ekwakhiweni kwemihlobo ye-oksijini esebenzako (i-ROS) (Kang et al. 2006). Njengombana ama-enzyme awohloza i-naphthalene aneenqhema ze-iron-sulfur, ngaphasi kokugandeleleka kwe-oxidative, i-iron ku-heme kanye namaphrotheyini we-iron-sulfur azoku-oxidated, okurholela ekutheni amaphrotheyini angasebenzi. I-Ferredoxin-NADP+ reductase (Fpr), kanye ne-superoxide dismutase (SOD), ilamula ukusabela kwe-redox okubuyiselwa emuva hlangana ne-NADP+/NADPH kanye namamolekhyuli amabili we-ferredoxin nofana i-flavodoxin, ngaleyo ndlela ikhupha i-ROS begodu ibuyisele isikhungo se-iron-sulphur ngaphasi kokugandeleleka kwe-oxidative (Li et al. 2006). Kubikwe bona kokubili i-Fpr ne-SodA (SOD) ku-Pseudomonas ingabangelwa kugandeleleka kwe-oxidative, begodu imisebenzi ekhuphukileko ye-SOD ne-catalase yabonwa emihlobeni emine ye-Pseudomonas (O1, W1, As1, kanye ne-G1) ngesikhathi sokukhula ngaphasi kwemibandela ye-naphthalene (Kang et al., 2006). Iimfundo zitjengise bona ukungezelelwa kwama-antioxidants afana ne-ascorbic acid nofana i-ferrous iron (Fe2+) kungakhuphula izinga lokukhula kwe-naphthalene. Lokha i-Rhodococcus erythropolis nayikhula ngaphakathi kwe-naphthalene, ukutloliswa kwamajini we-cytochrome P450 ahlobene nokugandeleleka kwe-oxidative kufaka hlangana i-sodA (Fe/Mn superoxide dismutase), i-sodC (Cu/Zn superoxide dismutase), kanye ne-recA kwakhuphuka (Sazykin et al., 2019). Ukuhlaziywa kwama-proteomic okulinganiselweko kwamaseli we-Pseudomonas akhuliswe ku-naphthalene kutjengise bona ukulawulwa kwamaphrotheyini ahlukahlukeneko ahlotjaniswa nokuphendula kokugandeleleka kwe-oxidative liqhinga lokujamelana nokugandeleleka (Herbst et al., 2013).
Iinlwana ezincani zibikwe bona zikhiqiza ama-biosurfactants ngaphasi kwesenzo semithombo yekhabhoni engathandi amanzi. Ama-surfactants la ma-amphiphilic surface active compounds angakha ama-aggregates lapho kuhlangana khona amafutha namanzi nofana umoya namanzi. Lokhu kukhuthaza ukuncibilika okungasikho begodu kwenza kube lula ukumunywa kwama-hydrocarbons anamakha, okurholela ekuwohlokeni okusebenzako (u-Rahman et al., 2002). Ngebanga lezakhiwo lezi, ama-biosurfactants asetjenziswa khulu emabubulweni ahlukahlukeneko. Ukungezelelwa kwamakhemikhali we-surfactants nofana ama-biosurfactants emasikweni wamabhaktheriya kungakhuphula ukusebenza kuhle nezinga lokuwohloka kwe-hydrocarbon. Hlangana nama-biosurfactants, ama-rhamnolipids akhiqizwa yi-Pseudomonas aeruginosa afundwe khulu begodu ahlukaniswe (Hisatsuka et al., 1971; Rahman et al., 2002). Ukungezelela, eminye imihlobo yama-biosurfactants ifaka hlangana ama-lipopeptides (ama-mucins avela ku-Pseudomonas fluorescens), i-emulsifier 378 (evela ku-Pseudomonas fluorescens) (u-Rosenberg no-Ron, 1999), ama-lipid we-trehalose disaccharide avela ku-Rhodococcus (Ramdahl, 1988), i-Bachenlus no-Sacillus, 2002), kanye ne-surfactant evela ku-Bacillus subtilis (Siegmund no-Wagner, 1991) kanye ne-Bacillus amyloliquefaciens (Zhi et al., 2017). Ama-surfactants anamandla la atjengiswe ukwehlisa ukugandeleleka kwephasi ukusuka ku-72 dynes/cm ukuya ngaphasi kwama-30 dynes/cm, okuvumela ukumuncwa okungcono kwe-hydrocarbon. Kubikwe bona i-Pseudomonas, i-Bacillus, i-Rhodococcus, i-Burkholderia neminye imihlobo yamabhaktheriya ingakhiqiza ama-rhamnolipid ahlukahlukeneko kanye nama-biosurfactants asekelwe ku-glycolipid lokha nayitjalwe nge-naphthalene ne-methylnaphthalene (Kanga et al., 1997; Puntus et al., 2005). I-Pseudomonas maltophilia CSV89 ingakhiqiza i-Biosur-Pm ye-extracellular biosurfactant lokha nayikhuliswa emakhompawundini anamakha afana ne-naphthoic acid (Phale et al., 1995). I-kinetics yokwakheka kwe-Biosur-Pm itjengise bona ukwakheka kwayo yindlela ethembele ekukhuleni ne-pH. Kwatholakala bona inani le-Biosur-Pm elikhiqizwa maseli ku-pH engathathi ihlangothi beliphezulu kunaleyo ku-pH 8.5. Amaseli akhuliswe ku-pH 8.5 bekangathandi amanzi begodu ane-affinity ephezulu yamakhompawundi we-aromatic ne-aliphatic ukudlula amaseli akhuliswe ku-pH 7.0. Ku-Rhodococcus spp. I-N6, isilinganiso esiphezulu sekhabhoni ukuya ku-nitrogen (C:N) kanye nokulinganiselwa kwensimbi zizinto ezihle khulu zokukhiqiza ama-biosurfactants angaphandle kwamaseli (Mutalik et al., 2008). Kwenziwe imizamo yokuthuthukisa ukwakheka kwe-biosurfactants (ama-surfactins) ngokuthuthukisa imihlobo nokuvutshelwa. Kodwana, i-titer ye-surfactant emkhathini wokukhulisa iphasi (1.0 g/L), okubeka itjhijilo ekukhiqizeni okukhulu (Jiao et al., 2017; Wu et al., 2019). Ngalokho-ke, iindlela zobunjiniyela bezakhi zofuzo zisetjenziselwe ukwenza ngcono ukwakheka kwayo. Kodwana, ukutjhugululwa kwayo kwezobunjiniyela kunzima ngebanga lobukhulu be-operon (∼25 kb) kanye nokulawulwa kwe-biosynthetic okuyinkimbinkimbi kwehlelo lokuzwa ikhoramu (Jiao et al., 2017; Wu et al., 2019). Iintjhuguluko ezinengi zobunjiniyela bezakhi zofuzo zenziwe emagciwaneni we-Bacillus, khulukhulu okuhloswe ngakho ukwandisa ukukhiqizwa kwe-surfactin ngokufaka esikhundleni se-promoter (srfA operon), ukuveza khulu iphrotheyini ye-surfactin export YerP kanye nama-regulatory factors ComX kanye ne-PhrC (Jiao et al., 2017). Nanyana kunjalo, iindlela zobunjiniyela bezakhi zofuzo zifikelele ukutjhugululwa kwezakhi zofuzo okukodwa nofana okumbalwa begodu azikafiki ekukhiqizweni kwezokuthengisa. Ngalokho-ke, ukufunda okungeziweko kweendlela zokuthuthukisa ezisekelwe elwazini kuyatlhogeka.
Iimfundo zokuwohloka kwe-PAH zenziwa khulu ngaphasi kweemeko ezijayelekileko zelabhorethri. Kodwana, eendaweni ezisilapheleko nofana eendaweni ezisilapheleko, izinto ezinengi eziphilako neziphilako (amazinga womtjhiso, i-pH, i-oksijini, ukutholakala kwezakhi, ukutholakala kwe-substrate, ezinye iinhlobo ze-xenobiotics, ukuvinjelwa komkhiqizo wokugcina, njll.) kutjengiswe bona zitjhugulula begodu zithonya amandla wokuwohloka weenlwanyana ezincani.
Izinga lokutjhisa linefuthe elikhulu ekuwohlokeni kwe-PAH. Njengoba amazinga womtjhiso akhuphuka, ukugxila kwe-oksijini encibilikileko kuyancipha, okuthinta ukusebenza kwemithambo yezinto eziphilako, ngombana zitlhoga i-oksijini yamamolekhyuli njengenye yezinto ezisekela ama-oksijini enza ukusabela kwe-hydroxylation nofana ukuhlukaniswa kwendandatho. Kuvamise ukutjheja bona amazinga womtjhiso aphakemeko atjhugulula ama-PAH abe makhompawundi anobuthi, ngaleyindlela avimbela ukuwohloka kwezinto eziphilako (Muller et al., 1998).
Kutjhejwe bona iindawo ezinengi ezingcolileko ze-PAH zinamanani we-pH aphezulu khulu, njengeendawo ezingcolileko ze-acid mine drainage (i-pH 1–4) kanye neendawo ezingcoliswe nge-alkaline leachate (i-pH 8–12). Iimeko lezi zingathinta khulu ikambiso yokuwohloka kwezinto eziphilako. Ngalokho-ke, ngaphambi kokusebenzisa ama-microorganisms ukulungisa i-bioremediation, kunconywa ukulungisa i-pH ngokufaka amakhemikhali afaneleko (anekhono lokunciphisa i-oksijini eliphakathi nendawo ukuya eliphasi khulu) njenge-ammonium sulfate nofana i-ammonium nitrate ehlabathini eline-alkaline nofana ukufakwa nge-calcium carbonate nofana i-magnesium carbonate ye-acid sites (Bowta et Gulen et 1995; Sar 2020).
Ukunikelwa kwe-oksijini endaweni ethintekileko yinto ekhawulela izinga lokuwohloka kwe-PAH. Ngebanga lobujamo be-redox bebhoduluko, iinkambo zokulungisa izinto eziphilako endaweni zivame ukutlhoga ukungeniswa kwe-oksijini evela emithonjeni yangaphandle (ukulima, ukutjhisa umoya, nokungezelela amakhemikhali) (Pardieck et al., 1992). U-Odenkranz et al. (1996). Olunye ucwaningo lwaphenya ukuwohloka kwe-phenol ne-BTEX ngaphakathi kwe-aquifer engcolileko ngokufaka i-sodium nitrate nokwakha imithombo yokukhipha ukufezekisa ukulungiswa okusebenzako (u-Bewley no-Webb, 2001).