Ofufuza azindikira ndikupanga enzyme yomwe imatha kugaya ndikudya zina zomwe timaipitsa kwambiri. mapulasitiki kupereka chiyembekezo chobwezeretsanso ndi kumenyana kuipitsa
Kuipitsa mapulasitiki ndiye vuto lalikulu la chilengedwe padziko lonse lapansi mu mawonekedwe a pulasitiki kuipitsa ndipo njira yabwino yothetsera vutoli ikadali yovuta. Ambiri mapulasitiki amapangidwa kuchokera ku petroleum kapena gasi wachilengedwe omwe ndi zinthu zosasinthika zomwe zimachotsedwa ndikukonzedwa pogwiritsa ntchito njira zogwiritsa ntchito mphamvu zambiri. Chifukwa chake, kupanga ndi kupanga kwawoko kumawononga kwambiri zachilengedwe zosalimba. Kuwonongeka kwa pulasitiki (makamaka ndi kutentha) kumayambitsa mpweya, madzi ndi dziko kuipitsa. Pafupifupi 79 peresenti ya pulasitiki yopangidwa m'zaka 70 zapitazi idatayidwa, m'malo otayiramo zinyalala kapena m'malo wamba pomwe pafupifupi 51 peresenti yokha ndi yomwe imasinthidwanso ndikuwotchedwa. Njira yowotchayi imayika ogwira ntchito omwe ali pachiwopsezo kuzinthu zapoizoni zomwe zimaphatikizapo zinthu zomwe zimayambitsa khansa. M’nyanjayi akuti muli tinthu ting’onoting’ono tokwana XNUMX thililiyoni ndipo tikuwononga zamoyo zam’madzi pang’onopang’ono. Ena mwa ma microparticles a pulasitiki amawombedwa ndi mpweya wotsogolera kuipitsa ndipo ndizotheka kwenikweni kuti titha kuwapumira. Palibe amene akananeneratu m’zaka za m’ma 1960 kuti kubwera ndi kutchuka kwa mapulasitiki tsiku lina kudzakhala cholemetsa ndi zinyalala zazikulu zapulasitiki zopezeka zikuyandama m’nyanja zathu zokongola, mpweya ndi kutayidwa pa malo athu amtengo wapatali.
pulasitiki kulongedza katundu ndiye chiwopsezo chachikulu komanso kugwiritsa ntchito mwachinyengo kwambiri mapulasitiki. Koma vuto ndilakuti thumba la pulasitiki lili paliponse, limagwiritsidwa ntchito pazifukwa zilizonse zazing'ono ndipo palibe ulamuliro pakugwiritsa ntchito kwake. Pulasitiki yopangidwa ngati imeneyi siiwononga zinthu, m'malo mwake imangokhala ndikuunjikana m'malo otayirako zinyalala ndipo imathandizira ku chilengedwe. kuipitsa. Pakhala pali zoyeserera za "kuletsa kwathunthu kwa pulasitiki", makamaka polystyrene yomwe imagwiritsidwa ntchito popakira. Komabe, izi sizikubweretsa zotsatira zomwe mukufuna chifukwa pulasitiki ikadali ponseponse pamtunda, mpweya ndi madzi ndipo ikukula nthawi zonse. Ndi zotetezeka kunena kuti pulasitiki sangawonekere m'maso nthawi zonse koma ili paliponse! Ndizomvetsa chisoni kuti sitingathe kuthana ndi zobwezeretsanso zinthu zapulasitiki ndikutaya vuto.
Mu phunziro lofalitsidwa mkati Zokambirana za National Academy of Sciences USA, ofufuza apeza chilengedwe chodziwika bwino enzyme zomwe zimadya pulasitiki. Uku kunali kutulukira mwamwayi pamene ankafufuza mmene enzyme yomwe inapezeka mu zinyalala yokonzeka kukonzedwanso pamalo ena ku Japan. Enzyme iyi yotchedwa Ideonella sakaiensis 201-F6, imatha "kudya" kapena "kudyetsa" pulasitiki yovomerezeka ya PET kapena polyethylene terephthalate yomwe imagwiritsidwa ntchito kwambiri mu mamiliyoni a matani a mabotolo apulasitiki. Enzymeyi idalola kuti mabakiteriya awononge pulasitiki ngati chakudya chawo. Palibe njira zobwezeretsanso zomwe zilipo pano za PET ndi mabotolo apulasitiki opangidwa ndi PET akupitilira zaka mazana ambiri m'chilengedwe. Kafukufukuyu motsogozedwa ndi magulu aku University of Portsmouth ndi National Renewable Energy Laboratory (NREL) ku United States Department of Energy's wapereka chiyembekezo chachikulu.
Cholinga choyambirira chinali kudziwa mawonekedwe a kristalo amitundu itatu ya enzyme yachilengedwe (yotchedwa PETase) ndikugwiritsa ntchito chidziwitsochi kuti mumvetsetse momwe enzymeyi imagwirira ntchito. Anagwiritsa ntchito kuwala kwamphamvu kwa X-ray - komwe kumawala kuwirikiza mabiliyoni 10 kuposa dzuwa - kuti amvetsetse momwe zimapangidwira ndikuwona maatomu amodzi. Miyendo yamphamvu yoteroyo inathandiza kumvetsetsa mmene enzyme imagwirira ntchito ndipo inapereka mapulani olondola kuti athe kupanga ma enzyme othamanga komanso achangu. Zinawululidwa kuti PETase imawoneka yofanana kwambiri ndi puloteni ina yotchedwa cutinase kupatula kuti PETase ili ndi chinthu chapadera komanso malo ogwirira ntchito "otseguka", omwe amaganiziridwa kuti amakhala ndi ma polima opangidwa ndi anthu (mmalo mwa chilengedwe). Kusiyana kumeneku kunawonetsa nthawi yomweyo kuti PETase ikhoza kusinthika makamaka m'malo okhala ndi PET motero imatha kutsitsa PET. Adasintha tsamba la PETase kuti liwoneke ngati cutinase. Chotsatira chinali zotsatira zosayembekezereka, PETase mutant inatha kutsitsa PET kuposa PETase yachilengedwe. Motero, pomvetsetsa ndi kuyesa kuwongolera mphamvu ya enzyme yachilengedwe, ofufuza adatha mwangozi kupanga puloteni yatsopano yomwe inali yabwino kuposa puloteni yachilengedwe pophwanya PET. mapulasitiki. Enzyme iyi imathanso kusokoneza polyethylene furandicarboxylate, kapena PEF, cholowa m'malo mwa bio-based PET plastics. Izi zidapanga chiyembekezo chothana ndi magawo ena monga PEF (Polyethylene Furanoate) kapena PBS (Polybutylene succinate). Zida zopangira uinjiniya wa ma enzyme ndi chisinthiko zitha kugwiritsidwa ntchito mosalekeza kuti ziwonjezeke. Ofufuza akuyang'ana njira yopititsira patsogolo enzyme kuti ntchito yake iphatikizidwe m'mafakitale akuluakulu amphamvu. Njira ya uinjiniya ndiyofanana kwambiri ndi ma enzymes omwe pakali pano akugwiritsidwa ntchito potsukira zotsukira kapena popanga mafuta. Ukadaulo ulipo ndipo motero kuthekera kwa mafakitale kuyenera kutheka m'zaka zikubwerazi.
Kafukufuku wina akufunika kuti timvetsetse mbali zina za kafukufukuyu. Choyamba, enzyme imaphwanya mapulasitiki akuluakulu kukhala tizidutswa tating'ono, motero amathandizira kukonzanso mabotolo apulasitiki koma pulasitiki yonseyi iyenera kubwezeretsedwanso. Pulasitiki "waung'ono" akapezeka atha kugwiritsidwa ntchito kuwatembenuza kukhala mabotolo apulasitiki. The enzyme sangathe kwenikweni "kupita kukapeza pulasitiki palokha" m'chilengedwe. Njira imodzi yomwe angagwiritsire ntchito ingakhale kubzala enzymeyi m'mabakiteriya ena omwe amatha kuswa pulasitiki pamlingo wokulirapo ndikupirira kutentha kwambiri. Komanso, mphamvu ya enzyme iyi iyenera kuganiziridwabe.
Zotsatira za njira yatsopano yotereyi yothanirana ndi zinyalala za pulasitiki zingakhale zapamwamba kwambiri padziko lonse lapansi. Takhala tikuyesera kuthana ndi vuto la pulasitiki kuyambira pomwe pulasitiki idayamba. Pakhala pali malamulo oletsa kugwiritsa ntchito pulasitiki imodzi komanso pulasitiki yokonzedwanso tsopano ndiyokondedwa kulikonse. Ngakhale masitepe ang'onoang'ono monga kuletsa matumba apulasitiki onyamulira m'masitolo akuluakulu akhala akufalikira pa TV. Mfundo ndi yakuti, tifunika kuchitapo kanthu mwamsanga ngati tikufuna kuti tisunge zinthu zathu dziko kuchokera ku pulasitiki kuipitsa. Ngakhale tikuyenera kupitiliza kugwiritsa ntchito zobwezeretsanso m'moyo wathu watsiku ndi tsiku kwinaku tikulimbikitsa ana athu kutero. Timafunikirabe yankho labwino la nthawi yayitali lomwe lingagwirizane ndi zoyesayesa zathu. Kafukufukuyu akuwonetsa chiyambi chothana ndi limodzi mwamavuto akulu omwe timakumana nawo dziko ikuyang'anizana.
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Kasupe (s)
Harry P et al. 2018. Makhalidwe ndi uinjiniya wa pulasitiki-owononga onunkhira polyesterase. Zokambirana za National Academy of Sciences. https://doi.org/10.1073/pnas.1718804115
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