Raws li hom khoom noj khoom haus, txhua yam kab mob uas muaj sia nyob tau muab faib ua ob hom loj: hetero- thiab autotrophs. Ib qho tshwj xeeb ntawm yav tas los yog lawv lub peev xwm los tsim cov ntsiab lus tshiab los ntawm cov pa roj carbon dioxide thiab lwm yam khoom siv tsis zoo.
Cov peev txheej ntawm lub zog uas txhawb nqa lawv cov haujlwm tseem ceeb txiav txim siab lawv faib rau hauv photoaphtotrophs (qhov chaw yog lub teeb) thiab chemoautotrophs (qhov chaw yog cov zaub mov). Thiab nyob ntawm lub npe ntawm cov substrate oxidized los ntawm chemoauthorthophytes, lawv muab faib ua hydrogen thiab nitrifying kab mob, nrog rau cov kab mob sulfur thiab hlau.
Zaj lus no yuav mob siab rau ntau pawg ntawm lawv - cov kab mob nitrifying.
Discovery keeb kwm
Txawm tias nyob rau hauv nruab nrab ntawm lub xyoo pua 19th, German kws tshawb fawb tau ua pov thawj tias cov txheej txheem ntawm nitrification yog lom. Empirically, lawv tau pom tias thaum chloroform tau ntxiv rau cov dej phwj tuaj, oxidation ntawm ammonia nres. Tab sis piav qhia vim li cas qhov no tshwm sim, lawv tsis uaua tau.
Qhov no tau ua tiav ob peb xyoos tom qab los ntawm Lavxias tus kws tshawb fawb Vinogradsky. Nws tau txheeb xyuas ob pawg kab mob uas maj mam koom nrog cov txheej txheem nitrification. Yog li, ib pab pawg tau ua kom cov oxidation ntawm ammonium rau nitrous acid, thiab pawg thib ob ntawm cov kab mob yog lub luag haujlwm rau nws hloov mus rau nitric acid. Tag nrho cov kab mob nitrifying koom nrog hauv cov txheej txheem no yog Gram-negative.
Txhim kho cov txheej txheem oxidation
Cov txheej txheem ntawm nitrite tsim los ntawm ammonium oxidation muaj ob peb theem, thaum lub sij hawm uas nitrogen-muaj cov tebchaw nrog txawv degrees ntawm oxidation ntawm pawg NH yog tsim.
thawj cov khoom ntawm ammonium oxidation yog hydroxylamine. Feem ntau, nws yog tsim los ntawm kev suav nrog cov pa oxygen molecular hauv NH 4 pawg, txawm tias cov txheej txheem no tsis tau raug pov thawj thaum kawg thiab tseem muaj kev sib cav.
Tom ntej no, hydroxylamine hloov mus rau nitrite. Piv txwv li, cov txheej txheem yog ua los ntawm kev tsim NOH (hyponitrite) nrog kev tso tawm ntawm nitrous oxide. Hauv qhov no, cov kws tshawb fawb xav txog kev tsim cov nitrous oxide tsuas yog los ntawm cov khoom sib txuas, vim tias txo cov nitrite.
Ntxiv rau kev tsim cov tshuaj lom neeg, ntau lub zog raug tso tawm thaum denitrification. Zoo ib yam li qhov tshwm sim nyob rau hauv heterotrophic aerobic kab mob, nyob rau hauv cov ntaub ntawv no lub synthesis ntawm ATP molecules yog txuam nrog redox txheej txheem, vim hais tias ntawm cov electrons yog pauv mus rau oxygen.
Thaum nitrite yog oxidized, cov txheej txheem ntawm kev thauj rov qab ua lub luag haujlwm tseem ceebelectrons. Kev suav nrog nws cov hluav taws xob hauv cov saw hlau tshwm sim ncaj qha hauv cytochromes (C-hom thiab / lossis A-hom), thiab qhov no yuav tsum muaj lub zog loj. Raws li qhov tshwm sim, chemoautotrophic nitrifying kab mob tau muab tag nrho nrog lub zog tsim nyog, uas yog siv rau cov txheej txheem ntawm lub tsev thiab assimilating carbon dioxide.
Nyob ntawm cov kab mob nitrifying
Plaub genera ntawm nitrobacteria koom nrog thawj theem ntawm nitrification:
- nitrosomonas;
- nitrocystis;
- nitrosolubus;
Nitrosospira Y
Los ntawm txoj kev, koj tuaj yeem pom cov kab mob nitrifying hauv daim duab qhia (daim duab hauv qab lub tshuab ntsuas).
Kev sim, ntawm lawv yog qhov nyuaj heev, thiab feem ntau tsis tuaj yeem ua tiav tag nrho ntawm ib qho ntawm cov kab lis kev cai, yog li lawv qhov kev xav tau yog qhov nyuaj heev. Tag nrho cov kab mob uas tau teev tseg muaj txog li 2-2.5 microns loj thiab feem ntau yog oval lossis puag ncig hauv cov duab (nrog rau kev zam ntawm nitrospira, uas muaj daim ntawv lo). Lawv muaj peev xwm ntawm binary fission thiab taw qhia txav vim flagella.
theem ob ntawm nitrification koom nrog:
- genus Nitrobacter;
- nitrospin yam;
Nyiaj teb Nitrococus.
Qhov kev tshawb fawb tshaj plaws ntawm cov kab mob ntawm cov genus Nitrbacter, muaj npe tom qab nws tus neeg nrhiav pom Vinogradsky. Cov kab mob nitrifying no muaj pear-puab hlwb, sib npaug los ntawm budding, nrog rau tsim ib lub xov tooj ntawm tes (vim lub flagellum) ntxhais cell.
qauv kab mob
Cov kab mob nitrifying tau kawm muaj cov qauv cellular zoo sib xws nrog lwm cov kab mob gram-tsis zoo. Ib txhia ntawm lawv muaj ib tug ncaj ncees tsim system ntawm lub puab daim nyias nyias uas tsim ib pawg nyob rau hauv nruab nrab ntawm lub cell, thaum nyob rau hauv lwm tus neeg lawv nyob rau hauv lub periphery los yog tsim ib tug qauv nyob rau hauv daim ntawv ntawm ib khob, muaj ob peb nplooj. Thaj, nws yog nrog cov formations uas enzymes yog txuam nrog rau hauv cov txheej txheem ntawm oxidation ntawm tej substrates los ntawm nitrifiers.
Nitrifying kab mob zaub mov hom
Nitrobacteria yog lub luag haujlwm autotrophs, vim tias lawv tsis tuaj yeem siv cov organic exogenous. Txawm li cas los xij, lub peev xwm ntawm qee hom kab mob nitrifying siv qee cov organic tebchaw tau raug sim qhia.
Nws tau pom tias cov substrate uas muaj cov poov xab autolysates, serine thiab glutamate nyob rau hauv qis concentrations, txhawb kev loj hlob ntawm nitrobacteria. Qhov no tshwm sim ob qho tib si nyob rau hauv lub xub ntiag ntawm nitrite thiab nyob rau hauv nws tsis muaj nyob rau hauv lub nutrient nruab nrab, txawm hais tias tus txheej txheem yog qeeb qeeb. Conversely, nyob rau hauv lub xub ntiag ntawm nitrite, oxidation ntawm acetate yog suppressed, tab sis kev koom ua ke ntawm nws cov carbon rau hauv cov protein, ntau yam amino acids, thiab lwm yam cellular Cheebtsam nce ho..
Raws li qhov tshwm sim ntawm ntau qhov kev sim, cov ntaub ntawv tau txais tias cov kab mob nitrifying tseem tuaj yeem hloov mus rau heterotrophic khoom noj khoom haus, tab sis yuav ua li cas tsim tau thiab ntev npaum li cas lawv tuaj yeem nyob hauv cov xwm txheej zoo li no tseem yuav pom. Ntev npaum li cov ntaub ntawv txaustsis sib haum los kos cov lus xaus kawg ntawm qhov teeb meem no.
Habitat thiab tseem ceeb ntawm nitrifying kab mob
Nitrifying kab mob yog chemoautotrophs thiab tau dav dav hauv cov xwm txheej. Lawv pom nyob txhua qhov chaw: hauv av, ntau yam substrates, nrog rau lub cev dej. Cov txheej txheem ntawm lawv cov haujlwm tseem ceeb ua rau muaj txiaj ntsig zoo rau lub voj voog nitrogen tag nrho hauv qhov xwm txheej thiab qhov tseeb tuaj yeem ncav cuag qhov loj me.
Piv txwv li, xws li cov kab mob xws li nitrocystis oceanus, cais tawm ntawm Dej Hiav Txwv Atlantic, belongs rau obligate halophiles. Nws tuaj yeem tsuas muaj nyob hauv dej hiav txwv lossis cov substrates uas muaj nws. Rau cov kab mob zoo li no, tsis tsuas yog qhov chaw nyob yog qhov tseem ceeb, tab sis kuj tseem muaj xws li pH thiab kub.
Txhua tus kab mob uas paub txog nitrifying yog cais raws li lub luag haujlwm aerobes. Lawv xav tau oxygen los oxidize ammonium rau nitrous acid thiab nitrous acid rau nitric acid.
Habitat condition
Lwm qhov tseem ceeb uas cov kws tshawb fawb tau txheeb xyuas yog qhov chaw uas cov kab mob nitrifying nyob yuav tsum tsis muaj cov organic teeb meem. Txoj kev xav tau muab tso rau pem hauv ntej tias cov kab mob no, hauv paus ntsiab lus, tsis tuaj yeem siv cov organic tebchaw los ntawm sab nraud. Lawv txawm raug hu ua obligate autotrophs.
Tom qab ntawd, qhov cuam tshuam tsis zoo ntawm cov piam thaj, urea, peptone, glycerin thiab lwm yam organics ntawm cov kab mob nitrifying tau rov ua pov thawj, tab sis kev sim tsis nres.
Qhov tseem ceeb ntawm nitrifying kab mob rauav
Txog tsis ntev los no, nws tau ntseeg tias nitrifiers muaj txiaj ntsig zoo rau cov av, ua rau nws muaj txiaj ntsig los ntawm kev rhuav tshem ammonium rau nitrates. Cov tom kawg tsis yog tsuas yog absorbed zoo los ntawm cov nroj tsuag, tab sis kuj los ntawm lawv tus kheej nce solubility ntawm tej yam minerals.
Txawm li cas los xij, nyob rau xyoo tas los no, kev xav txog kev tshawb fawb tau hloov pauv. Cov txiaj ntsig tsis zoo ntawm cov kab mob tau piav qhia hauv av fertility tau tshwm sim. Nitrifying kab mob, tsim nitrates, acidify ib puag ncig, uas tsis yog ib txwm ib tug zoo tshaj plaws, thiab kuj provoke lub saturation ntawm av nrog ammonium ions mus rau ib tug ntau dua li nitrates. Ntxiv mus, nitrates muaj peev xwm txo tau rau N 2 (thaum lub sij hawm denitrification), uas ua rau cov av depletion hauv nitrogen.
Dab tsi yog qhov phom sij ntawm cov kab mob nitrifying?
Qee hom kab mob nitrobacteria nyob rau hauv lub xub ntiag ntawm cov organic substrate tuaj yeem oxidize ammonium, tsim hydroxylamine, thiab tom qab nitrites thiab nitrates. Tsis tas li ntawd, raws li qhov tshwm sim ntawm cov tshuaj tiv thaiv, hydroxamic acids tuaj yeem tshwm sim. Ntxiv mus, ntau tus kab mob ua cov txheej txheem ntawm nitrification ntawm ntau lub tebchaw uas muaj nitrogen (oximes, amines, amides, hydroxamates thiab lwm yam nitro compounds).
Qhov ntsuas ntawm heterotrophic nitrification nyob rau hauv qee yam mob tuaj yeem tsis tsuas yog loj, tab sis kuj muaj kev puas tsuaj loj heev. Qhov txaus ntshai nyob rau hauv qhov tseeb hais tias nyob rau hauv lub chav kawm ntawm xws transformation, tsim cov tshuaj lom, mutagens thiab carcinogens tshwm sim. Yog li ntawd, cov kws tshawb fawb nyob zetab tom kawm txog lub ncauj lus no.
Cov lim dej uas ib txwm nyob ntawm tes
Nitrifying kab mob tsis yog lub tswv yim paub daws teeb, tab sis ib hom kev ua neej zoo heev. Ntxiv mus, lawv feem ntau siv los ntawm tib neeg.
Piv txwv li, cov kab mob no yog ib feem ntawm cov lim dej rau cov thoob dej yug ntses. Hom kev tu no tsis tshua kim thiab tsis ua haujlwm hnyav li kev tu txhua yam, tab sis tib lub sijhawm nws yuav tsum ua raws li qee yam kev mob txhawm rau kom ntseeg tau tias kev loj hlob thiab kev ua haujlwm tseem ceeb ntawm cov kab mob nitrifying.
Qhov zoo tshaj plaws microclimate rau lawv yog qhov kub thiab txias (qhov no dej) ntawm qhov kev txiav txim ntawm 25-26 degrees Celsius, ib qho khoom noj tas li ntawm oxygen thiab muaj cov nroj tsuag dej.
Nitrifying kab mob hauv kev ua liaj ua teb
Yuav kom nce qoob loo, cov neeg ua liaj ua teb siv ntau yam chiv uas muaj cov kab mob nitrifying.
Khoom noj khoom haus ntawm cov av hauv qhov no yog muab los ntawm nitrobacteria thiab azotobacteria. Cov kab mob no tshem tawm cov khoom tsim nyog los ntawm cov av thiab dej, uas tsim kom muaj zog txaus thaum lub sijhawm oxidation. Qhov no yog cov txheej txheem hu ua chemosynthesis, thaum lub zog tau txais yog siv los tsim cov molecules complex ntawm organic keeb kwm los ntawm carbon dioxide thiab dej.
Cov kab mob me me no tsis xav tau cov khoom noj los ntawm lawv ib puag ncig - lawv tuaj yeem tsim lawv tus kheej. Yog li, yog tias cov nroj tsuag ntsuab, uas tseem yog autotrophs, xav tauhnub ci, ces nws tsis tsim nyog rau cov kab mob nitrifying.
Tshuaj av tus kheej
Av yog qhov zoo tshaj plaws substrate rau kev loj hlob thiab kev loj hlob ntawm cov nroj tsuag, tab sis kuj muaj ntau yam kab mob. Yog li ntawd, nws cov mob ib txwm muaj thiab sib npaug sib npaug yog qhov tseem ceeb heev.
Nws yuav tsum nco ntsoov tias cov kab mob nitrifying kuj muab kev ntxuav cov av. Lawv, nyob rau hauv cov av, reservoir los yog humus, hloov ammonia, uas yog tso tawm los ntawm lwm yam kab mob thiab pov tseg organic cov ntaub ntawv, mus rau hauv nitrates (kom meej meej, mus rau hauv ntsev ntawm nitric acid). Tag nrho cov txheej txheem muaj ob kauj ruam:
- Oxidation ntawm ammonia rau nitrite.
- Oxidation ntawm nitrite rau nitrate.
Tib lub sijhawm, txhua theem yog muab los ntawm cov kab mob sib cais.
Vim lub siab phem
Kev ncig ntawm lub zog thiab kev saib xyuas lub neej hauv ntiaj teb yog ua tau vim kev ua raws li qee txoj cai ntawm kev muaj sia nyob ntawm txhua yam muaj sia. Thaum xub thawj siab ib muag, nws yog ib qho nyuaj rau to taub dab tsi yog nyob rau hauv ceg txheem ntseeg, tab sis qhov tseeb txhua yam yog heev yooj yim.
Cia li xav txog cov duab hauv qab no los ntawm phau ntawv kawm:
- Cov tshuaj tsis muaj kab mob yog ua tiav los ntawm cov kab mob thiab yog li tsim cov kev mob zoo hauv cov av rau kev loj hlob thiab kev noj haus ntawm cov nroj tsuag.
- Lawv, dhau los, yog qhov tseem ceeb ntawm lub zog rau feem ntau herbivores.
- Txoj kab txuas txuas ntxiv ntawm lub neej no yog cov tsiaj nyeg, lub zog uas yog,raws li lawv cov herbivorous counterparts.
- Tib neeg paub tias yog cov tsiaj txhu apex, txhais tau tias peb tuaj yeem tau txais lub zog ntawm ob lub ntiaj teb cog thiab tsiaj ntiaj teb.
- Thiab peb tus kheej lub neej tseem tshuav, nrog rau cov nroj tsuag thiab tsiaj txhu, ua cov as-ham substrate rau cov kab mob.
Yog li, lub voj voog vicious tau txais, ua haujlwm tsis tu ncua thiab muab txoj sia rau tag nrho lub neej hauv ntiaj teb. Paub txog cov ntsiab cai no, nws tsis yog nyuaj rau xav txog yuav ua li cas multifaceted thiab tiag limitless lub hwj chim ntawm xwm thiab tag nrho cov nyob.
Zoo kawg
Nyob rau hauv tsab xov xwm no, peb sim teb cov lus nug ntawm dab tsi nitrifying kab mob nyob rau hauv biology. Raws li koj tuaj yeem pom, txawm tias muaj pov thawj tsis txaus ntseeg ntawm cov haujlwm tseem ceeb, kev ua haujlwm thiab kev cuam tshuam ntawm cov kab mob no, tseem muaj ntau qhov teeb meem tsis sib haum xeeb uas xav tau kev tshawb fawb ntxiv.
Nitrifying kab mob yog cais raws li chemotrophs. Ntau yam minerals pab ua lub zog rau lawv. Txawm hais tias lawv qhov microscopic loj, cov kab mob no muaj kev cuam tshuam loj rau lub ntiaj teb nyob ib puag ncig lawv.
Raws li koj paub, chemotrophs tsis tuaj yeem nqus cov organic sib txuas uas nyob hauv substrate (av av lossis dej). Ntawm qhov tsis sib xws, lawv tsim cov khoom siv hauv tsev tsim kom muaj lub neej nyob thiab ua haujlwm ntawm tes.
