2.3 Dissimilitary nitrate reduction According to Croal et al., (2004), bacteria such as Shewanella oneidensis can reduce Nitrate (NO3-) for the purpose of assimilation and in this research is consider only those that engage in dissimilatory nitrate reduction Ammonium (DNRA). Which is the process of using (NO3-) as a terminal electron acceptor in anaerobic respiration. (NO3-)-reducing bacteria is mainly have habitat in freshwater and marine environments. They play significantly affect in the biogeochemical cycling of carbon, hydrogen and variety of trace metal elements. Nitrate(NO3-)reducing bacteria are important for bioremediation purpose. It acts as oxidizing toxic organic compounds to carbon dioxide (CO2) and reduce immobilizing radionuclides
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The direct reduction of nitrate to ammonium (DNRA) can be implemented by organisms with the NRF-gene. Nuclear respiratory factor gene (NRF-gene) is functions as a transcription factor which activates the expression of metabolic genes regulating cellular growth and nuclear genes required for respiration in organisms. This is a less common method of nitrate reduction than denitrification in most ecosystems. Other genes involved in denitrification include NIR (nitrite reductase) and NOS (nitrous oxide reductase), which are possessed by such organisms as Shewanella …show more content…
It is a well known bacteria for having versatility respiratory system. Nitrate is reduce in dominant pathway through reduction of nitrate to nitrite and nitrite reduce to ammonium. According to Cruz-Garcia et al., (2007) the first important step of the respiratory nitrate ammonification is carried out by a NAP system, which lack of NapC and result of producing nitrite which can be further used in order to reduce into ammonium. Next step is catalyzed by an NRF system based on the periplasmic nitrite reductase presence encoded by nrfA. However, the experimental validation is deficient. CymA, which a c-type cytochrome is suggested for belonging to the NapC/NirT group where the same place for NapC and
The direct reduction of nitrate to ammonium (DNRA) can be implemented by organisms with the NRF-gene. Nuclear respiratory factor gene (NRF-gene) is functions as a transcription factor which activates the expression of metabolic genes regulating cellular growth and nuclear genes required for respiration in organisms. This is a less common method of nitrate reduction than denitrification in most ecosystems. Other genes involved in denitrification include NIR (nitrite reductase) and NOS (nitrous oxide reductase), which are possessed by such organisms as Shewanella …show more content…
It is a well known bacteria for having versatility respiratory system. Nitrate is reduce in dominant pathway through reduction of nitrate to nitrite and nitrite reduce to ammonium. According to Cruz-Garcia et al., (2007) the first important step of the respiratory nitrate ammonification is carried out by a NAP system, which lack of NapC and result of producing nitrite which can be further used in order to reduce into ammonium. Next step is catalyzed by an NRF system based on the periplasmic nitrite reductase presence encoded by nrfA. However, the experimental validation is deficient. CymA, which a c-type cytochrome is suggested for belonging to the NapC/NirT group where the same place for NapC and