Qhov sib txawv tseem ceeb ntawm cov kab mob nitrogen-kho cov kab mob thiab cov kab mob denitrifying yog cov kab mob uas kho cov kab mob nitrogen hloov atmospheric nitrogen rau hauv ammonium lossis ammonia hauv av thaum denitrifying cov kab mob hloov nitrates hauv av rau hauv atmospheric nitrogen.
Lub voj voog nitrogen yog ib lub voj voog biogeochemical tseem ceeb. Muaj ob peb kauj ruam hauv lub voj voog nitrogen. Ntawm lawv, nitrogen fixation thiab denitrification yog ob theem. Hauv nitrogen fixation, nitrogen-fixing kab mob hloov atmospheric nitrogen rau hauv ammonia lossis ammonium ions hauv av. Hauv denitrification, cov kab mob denitrifying hloov nitrates hauv av rau hauv atmospheric nitrogen. Nitrogen-fixing kab mob ua rau cov av fertility. Hauv qhov sib piv, cov kab mob denitrifying txo cov av fertility.
Nitrogen-fixing Bacteria yog dab tsi?
Nitrogen-fixing bacteria yog ib pawg ntawm cov kab mob uas hloov atmospheric nitrogen los yog nitrogen gas rau hauv ammonia lossis ammonium ions hauv av. Azotobacter, Bacillus, Clostridium, thiab Klebsiella yog ob peb yam piv txwv ntawm cov kab mob kho nitrogen. N2 roj nyiaj rau kwv yees li 78% ntawm huab cua los ntawm ntim. Atmospheric nitrogen nkag mus rau hauv lub ntiaj teb no nyob los ntawm kev ua ntawm cov nitrogen-kho cov kab mob. Yog li ntawd, lawv hloov N2 roj rau NH3 thiab NH4+ ions. Ces cov NH3 thiab NH4+ ions ncig ntawm lub voj voog nitrogen, muab nitrogen rau tag nrho cov kab mob nyob. Nitrogen-fixing kab mob siv ib qho enzyme hu ua nitrogenase los hloov cov roj nitrogen rau hauv ammonia. Nitrogenase enzyme catalyzes hloov pauv ntawm atmospheric nitrogen rau hauv ammonia los ntawm kev rhuav tshem ntawm peb daim ntawv cog lus thiab sib ntxiv ntawm peb hydrogen atoms rau txhua nitrogen atom. Nitrogen-kho cov kab mob ua haujlwm tau zoo dua hauv qhov chaw anaerobic.
Daim duab 01: Nitrogen-Kho cov kab mob hauv cov hauv paus Nodules
Qee cov kab mob uas kho nitrogen yog cov kab mob hauv av dawb (Azotobacter) thiab cov kab mob dawb-nyob, thaum qee cov kab mob xws li Rhizobium thiab Bradyrhizobium, thiab lwm yam nyob hauv kev sib raug zoo nrog cov nroj tsuag leguminous. Nitrogen fixation yog qhov tseem ceeb rau cov nroj tsuag kev loj hlob, kev loj hlob thiab kev tsim khoom. Yog li ntawd, nitrogen-fixing kab mob nce av fertility thiab ua liaj ua teb productivity.
Dab tsi yog Denitrifying Bacteria?
Cov kab mob Denitrifying yog ib pawg ntawm cov kab mob uas hloov nitrates hauv av mus rau hauv atmospheric nitrogen gas. Cov txheej txheem no hu ua denitrification, thiab nws yog ib qho ntawm cov kauj ruam tseem ceeb ntawm lub voj voog nitrogen. Denitrifying cov kab mob koom nrog tso cov roj nitrogen ruaj khov rov qab rau hauv cov huab cua thiab ua tiav lub voj voog nitrogen. Cov kab mob no siv ntau cov enzymes, suav nrog nitrate reductase, nitrite reductase, nitric oxide reductase thiab nitrous oxide reductase. Cov kab mob xws li Pseudomonas, Alkaligenes, Bacillus thiab Clostridium, thiab lwm yam yog ob peb yam piv txwv ntawm cov kab mob denitrifying. Lawv yog cov facultative anaerobic heterotrophic kab mob. Lawv ua hauj lwm nyob rau hauv anaerobic los yog anoxic tej yam kev mob xws li waterlogged av. Tsis tas li ntawd, cov kab mob no nyob hauv ntau qhov chaw nyob, suav nrog thaj chaw huab cua uas muaj saline thiab kub heev.
Daim duab 02: Denitrifying Bacterium
Cov kab mob Denitrifying siv nitrate lossis oxidized nitrogen raws li lawv txoj kev ua pa substrate thaum tsis muaj oxygen raws li lub davhlau ya nyob twg electron txais. Yog li ntawd, nitrate yog tso tawm raws li gaseous nitrogen rau hauv cov huab cua. Nitrate yog cov nroj tsuag siv tau cov nitrogen hauv av. Txij li cov kab mob denitrifying tshem cov nitrate los ntawm cov av, lawv muaj lub luag haujlwm txo cov av fertility thiab kev ua liaj ua teb.
Dab tsi zoo sib xws ntawm Nitrogen-fixing Bacteria thiab Denitrifying Bacteria?
- Ob leeg kho cov kab mob nitrogen thiab cov kab mob denitrifying yog ib feem tseem ceeb ntawm lub voj voog nitrogen.
- Lawv yog cov kab mob hauv av.
- Lawv siv cov enzymes los hloov cov ntawv nitrogen.
- Ob leeg kho cov kab mob nitrogen thiab cov kab mob denitrifying nyiam ib puag ncig anaerobic.
Qhov txawv ntawm Nitrogen-fixing Bacteria thiab Denitrifying Bacteria yog dab tsi?
Nitrogen-fixing bacteria yog cov kab mob uas hloov cov pa nitrogen dawb rau hauv ammonia lossis ammonium hauv av. Cov kab mob denitrifying yog cov kab mob uas hloov nitrates nyob rau hauv cov av kom dawb atmospheric nitrogen. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm nitrogen-kho cov kab mob thiab cov kab mob denitrifying. Azotobacter, Bacillus, Clostridium, thiab Klebsiella yog ob peb hom kab mob uas kho nitrogen, thaum Pseudomonas, Alkaligenes, Bacillus, thiab lwm yam, yog ntau hom kab mob denitrifying.
Cov duab hauv qab no qhia ntau qhov sib txawv ntawm cov kab mob nitrogen-kho cov kab mob thiab cov kab mob denitrifying hauv daim ntawv.
Summary – Nitrogen-fixing Bacteria vs Denitrifying Bacteria
Nitrogen-fixing bacteria hloov atmospheric nitrogen rau ammonia hauv av. Denitrifying kab mob hloov nitrates nyob rau hauv cov av mus rau hauv atmospheric nitrogen dawb. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm nitrogen-kho cov kab mob thiab cov kab mob denitrifying. Txij li thaum nitrogen-kho cov kab mob ntxiv nitrogen rau hauv av, lawv pab ua kom cov av fertility thiab kev ua liaj ua teb. Hauv qhov sib piv, cov kab mob denitrifying pab txo cov av fertility thiab ua liaj ua teb productivity.
