kab mob ntshav liab yog dab tsi? Cov kab mob no yog pigmented nrog bacteriochlorophyll a lossis b nrog rau ntau yam carotenoids uas muab lawv cov xim xws li ntshav, liab, xim av thiab txiv kab ntxwv. Qhov no yog ib pawg neeg sib txawv. Lawv tuaj yeem muab faib ua ob pawg: cov kab mob ntshav qab zib thiab cov kab mob ntshav yooj yim (Rhodospirillaceae). 2018 Frontiers in Energy Research daim ntawv thov siv lawv li bio-resources.
Biology
Cov kab mob ntshav liab feem ntau yog photoautotrophic, tab sis chemoautotrophic thiab photoheterotropic hom kuj paub. Lawv yuav yog mixotrophs muaj peev xwm ua pa aerobic thiab fermentation.
Photosynthesis ntawm cov kab mob ntshav qab zib tshwm sim hauv cov chaw tshuaj tiv thaiv ntawm cov cell membrane qhov chaw photosynthetic pigments (piv txwv li bacteriochlorophyll, carotenoids) thiab pigment-binding proteins tau nkag mus rau hauv invagination los tsim cov vesicles, tubules, lossis ib leeg-pair lossis stacked lamellar nplooj ntawv. Qhov no hu ua intracytoplasmic membrane (ICM), uas muaj qhov lojthaj chaw saum npoo kom ua kom pom lub teeb pom kev zoo.
Physics thiab chemistry
Piv txwv kab mob siv cyclic electron hloov pauv los ntawm cov tshuaj tiv thaiv redox. Lub teeb sib sau ua ke nyob ib puag ncig lub chaw tshuaj tiv thaiv (RC) khaws cov photons hauv daim ntawv ntawm lub zog resonant, ntes P870 lossis P960 chlorophyll pigments nyob hauv RC. Zoo siab electrons voj voog ntawm P870 mus rau quinones QA thiab QB, ces mus rau cytochrome bc1, cytochrome c2 thiab rov qab mus rau P870. Qhov txo qis quinone QB nyiam ob cytoplasmic protons thiab dhau los ua QH2, nws thiaj li raug oxidized thiab tso protons mus rau hauv lub periplasm los ntawm cytochrome bc1 complex. Qhov txiaj ntsig sib koom ntawm cytoplasm thiab periplasm tsim lub zog tsav proton siv los ntawm ATP synthase los tsim ATP zog.
Piv txwv kab kab mob kuj hloov hluav taws xob los ntawm lwm tus neeg pub dawb ncaj qha rau cytochrome bc1 los tsim NADH lossis NADPH siv rau anabolism. Lawv yog cov crystals ib leeg vim tias lawv tsis siv dej ua cov khoom siv hluav taws xob los tsim cov pa oxygen. Ib hom kab mob ntshav liab, hu ua ntshav sulfur kab mob (PSB), siv sulfide los yog sulfur ua cov khoom siv hluav taws xob. Lwm hom, hu ua cov kab mob ntshav qab zib uas tsis yog sulfur, feem ntau siv hydrogen los ua cov khoom siv hluav taws xob, tab sis kuj tseem tuaj yeem siv sulfide lossis organic compounds ntawm qis dua piv rau PSB.
kab mob violetTsis muaj cov khoom siv hluav taws xob sab nraud txaus los txo qis NAD(P) + rau NAD(P)H, yog li lawv yuav tsum siv lawv cov quinones txo kom txo NAD(P) + enanghorously. Cov txheej txheem no yog tsav los ntawm lub zog tsav ntawm proton thiab hu ua qhov rov qab ntws ntawm electrons.
Sulfur es tsis txhob oxygen
Cov kab mob ntshav tsis muaj sulfur yog thawj cov kab mob uas pom tau tias muaj photosynthesis tsis muaj oxygen raws li cov khoom lag luam. Hloov chaw, lawv cov khoom los ntawm cov khoom yog sulfur. Qhov no tau raug pov thawj thaum cov tshuaj tiv thaiv kab mob mus rau qhov sib txawv ntawm cov pa oxygen tau tsim ua ntej. Cov kab mob tau pom sai sai txav deb ntawm cov kab me me ntawm cov pa oxygen. Tom qab ntawd lawv tau ua ib qho kev sim uas lawv siv ib lub tais ntawm cov kab mob, thiab lub teeb tau tsom mus rau ib feem ntawm nws, thiab lwm qhov tau tso rau hauv qhov tsaus ntuj. Vim cov kab mob tsis tuaj yeem muaj sia nyob tsis muaj lub teeb, lawv txav mus rau hauv lub voj voog ntawm lub teeb. Yog tias cov khoom lag luam ntawm lawv lub neej yog cov pa oxygen, qhov kev ncua deb ntawm tib neeg yuav loj dua vim tias cov pa oxygen ntau ntxiv. Tab sis vim yog tus cwj pwm ntawm cov kab mob ntshav thiab ntsuab hauv lub teeb tsom, nws tau txiav txim siab tias cov khoom los ntawm cov kab mob photosynthesis tsis tuaj yeem yog oxygen.
Cov kws tshawb fawb tau pom tias qee cov kab mob ntshav qab zib niaj hnub no cuam tshuam nrog mitochondria, cov kab mob symbiotic hauv cov nroj tsuag thiab tsiaj hlwb uas ua raws li cov kab mob. Kev sib piv ntawm lawv cov qauv protein qhia tau hais tias muaj ib tug poj koob yawm txwv ntawm cov qauv no. Ntshav ntsuab kab mob thiab heliobacteria kuj muaj cov qauv zoo sib xws.
Cov kab mob Sulfur (cov kab mob sulfur)
Purple sulfur bacteria (PSB) yog ib feem ntawm Proteobacteria pab pawg muaj peev xwm ntawm photosynthesis, sib sau ua ke hu ua kab mob ntshav. Lawv yog cov anaerobic lossis microaerophilic thiab feem ntau pom muaj nyob rau hauv cov dej stratified, nrog rau cov dej kub, cov pas dej ua ke, thiab cov microbial aggregations hauv cov dej siab. Tsis zoo li cov nroj tsuag, algae, thiab cyanobacteria, ntshav sulfur kab mob tsis siv dej los ua tus neeg sawv cev txo qis thiab yog li tsis tsim cov pa oxygen. Hloov chaw, lawv tuaj yeem siv cov sulfur hauv daim ntawv sulfide lossis thiosulfate (thiab qee hom kuj tseem siv H2, Fe2+ lossis NO2-) ua ib qho khoom siv hluav taws xob hauv lawv txoj hauv kev photosynthesis. Sulfur yog oxidized los tsim cov hlau sulfur granules. Qhov no, nyob rau hauv lem, tuaj yeem oxidized los ua sulfuric acid.
Kev faib tawm
Cov kab mob ntshav qab zib tau muab faib ua ob tsev neeg: Chromatiaceae thiab Ectothiorhodospiraceae, uas tsim cov sulfur granules sab hauv thiab sab nraud raws li qhov sib txawv ntawm cov qauv ntawm lawv daim nyias nyias. Lawv tsim ib feem ntawm qhov kev txiav txim Chromatiales, suav nrog hauv gamma division Proteobacteria. Lub genus Halothiobacillus kuj suav nrog hauv Chromatiales hauv nws tsev neeg, tab sis nws tsis yog photosynthetic.
Nyob zoo
Cov kab mob ntshav qab zib feem ntau pom muaj nyob hauv thaj chaw illuminated anoxic ntawm cov pas dej thiab lwm qhov chaw nyob hauv dej uas hydrogen sulfide accumulates,thiab tseem nyob rau hauv "sulfur springs" qhov twg geochemically los yog biologically tsim hydrogen sulfide tuaj yeem ua rau cov kab mob ntshav sulfur tuaj yeem tawg. Photosynthesis xav tau cov mob anoxic; Cov kab mob no tsis tuaj yeem vam meej nyob rau hauv ib puag ncig oxygenated.
Meromictic (mus tas li stratified) pas dej yog qhov zoo tshaj plaws rau kev loj hlob ntawm cov kab mob ntshav sulfur. Lawv stratify vim hais tias lawv muaj denser (feem ntau physiological) dej nyob rau hauv qab thiab tsawg ntom (feem ntau yog cov dej tshiab) ze rau saum npoo. Kev loj hlob ntawm cov kab mob ntshav qab zib kuj tseem txhawb nqa los ntawm kev tso rau hauv cov pas dej holomictic. Lawv yog cov thermally stratified: thaum lub caij nplooj ntoos hlav thiab lub caij ntuj sov, cov dej saum npoo heats li, ua rau cov dej sab sauv tsawg dua qhov qis, uas muab kev ruaj khov stratification rau kev loj hlob ntawm cov kab mob ntshav sulfur. Yog tias muaj sulfate txaus los txhawb sulfation, cov sulfide tsim nyob rau hauv cov sediment diffuses nce mus rau hauv cov dej hauv qab anoxic uas cov kab mob ntshav sulfur tuaj yeem tsim cov cell loj.
Kawg
Cov kab mob ntshav liab kuj tuaj yeem pom thiab yog cov khoom tseem ceeb hauv cov kab mob nruab nrab ntawm cov kab mob. Cov pawg xws li Sippewissett microbial ntaub pua tsev muaj ib puag ncig zoo vim yog cov dej ntws thiab cov dej tshiab tuaj, ua rau muaj qhov sib txawv zoo ib yam li cov pas dej meromictic. Kev loj hlob ntawm cov kab mob ntshav sulfuryog activated raws li sulfur yog muab los ntawm kev tuag thiab decomposition ntawm microorganisms nyob saum lawv. Lub stratification thiab qhov chaw ntawm leej faj tso cai rau PSB kom loj hlob nyob rau hauv cov tidal basins uas aggregations tshwm sim. PSB tuaj yeem pab txhim kho microbial sediment los ntawm kev tso tawm ntawm cov khoom siv hluav taws xob ntxiv uas tuaj yeem khi cov sediment hauv cov dej ntws.
Ecology
Cov kab mob ntshav qab zib muaj peev xwm cuam tshuam rau ib puag ncig los ntawm kev txhawb nqa cov khoom noj khoom haus, siv lawv cov metabolism los hloov ib puag ncig. Lawv tuaj yeem ua lub luag haujlwm tseem ceeb hauv kev tsim thawj zaug los ntawm kev cuam tshuam cov pa roj carbon monoxide los ntawm kev kho cov pa roj carbon monoxide. Ntshav sulfur kab mob kuj tseem ua rau tsim cov phosphorus hauv lawv qhov chaw nyob. Los ntawm cov haujlwm tseem ceeb ntawm cov kab mob no, phosphorus, uas txwv tsis pub cov khoom noj hauv oxic txheej ntawm cov pas dej, tau siv dua thiab muab rau cov kab mob heterotrophic siv. Qhov no qhia tau hais tias txawm hais tias cov kab mob ntshav qab zib tau pom nyob rau hauv cov txheej txheem anoxic ntawm lawv qhov chaw nyob, lawv muaj peev xwm txhawb kev loj hlob ntawm ntau yam kab mob heterotrophic los ntawm kev muab cov as-ham inorganic rau cov txheej txheem oxide uas tau hais tseg.
