Related Research Articles
Anaerobic respiration is respiration using electron acceptors other than molecular oxygen (O2). Although oxygen is not the final electron acceptor, the process still uses a respiratory electron transport chain.
Denitrification is a microbially facilitated process where nitrate (NO3−) is reduced and ultimately produces molecular nitrogen (N2) through a series of intermediate gaseous nitrogen oxide products. Facultative anaerobic bacteria perform denitrification as a type of respiration that reduces oxidized forms of nitrogen in response to the oxidation of an electron donor such as organic matter. The preferred nitrogen electron acceptors in order of most to least thermodynamically favorable include nitrate (NO3−), nitrite (NO2−), nitric oxide (NO), nitrous oxide (N2O) finally resulting in the production of dinitrogen (N2) completing the nitrogen cycle. Denitrifying microbes require a very low oxygen concentration of less than 10%, as well as organic C for energy. Since denitrification can remove NO3−, reducing its leaching to groundwater, it can be strategically used to treat sewage or animal residues of high nitrogen content. Denitrification can leak N2O, which is an ozone-depleting substance and a greenhouse gas that can have a considerable influence on global warming.
Heliobacteria are a unique subset of prokaryotic bacteria that process light for energy. Distinguishable from other phototrophic bacteria, they utilize a unique photosynthetic pigment, bacteriochlorophyll g and are the only known Gram-positive phototroph. They are a key player in symbiotic nitrogen fixation alongside plants, and share a reaction center with green-sulfur bacteria.
Nitrosomonas is a genus of Gram-negative bacteria, belonging to the Betaproteobacteria. It is one of the five genera of ammonia-oxidizing bacteria and, as an obligate chemolithoautotroph, uses ammonia as an energy source and as a carbon source in presence of oxygen. Nitrosomonas are important in the global biogeochemical nitrogen cycle, since they increase the bioavailability of nitrogen to plants and in the denitrification, which is important for the release of nitrous oxide, a powerful greenhouse gas. This microbe is photophobic, and usually generate a biofilm matrix, or form clumps with other microbes, to avoid light. Nitrosomonas can be divided into six lineages: the first one includes the species Nitrosomonas europea, Nitrosomonas eutropha, Nitrosomonas halophila, and Nitrosomonas mobilis. The second lineage presents the species Nitrosomonas communis, N. sp. I and N. sp. II, meanwhile the third lineage includes only Nitrosomonas nitrosa. The fourth lineage includes the species Nitrosomonas ureae and Nitrosomonas oligotropha and the fifth and sixth lineages include the species Nitrosomonas marina, N. sp. III, Nitrosomonas estuarii and Nitrosomonas cryotolerans.
Denitrifying bacteria are a diverse group of bacteria that encompass many different phyla. This group of bacteria, together with denitrifying fungi and archaea, is capable of performing denitrification as part of the nitrogen cycle. Denitrification is performed by a variety of denitrifying bacteria that are widely distributed in soils and sediments and that use oxidized nitrogen compounds in absence of oxygen as a terminal electron acceptor. They metabolise nitrogenous compounds using various enzymes, turning nitrogen oxides back to nitrogen gas or nitrous oxide.
Microbial metabolism is the means by which a microbe obtains the energy and nutrients it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics. The specific metabolic properties of a microbe are the major factors in determining that microbe's ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles.
Paracoccus denitrificans, is a coccoid bacterium known for its nitrate reducing properties, its ability to replicate under conditions of hypergravity and for being a relative of the eukaryotic mitochondrion.
Hydrogen oxidizing bacteria are a group of facultative autotrophs that can use hydrogen as an electron donor.
Comamonas nitrativorans is a Gram-negative, oxidase- and catalase-positive bacterium from the genus Comamonas, which was isolated from a denitrifying reactor treating landfill leachate. C. nitrativorans has the ability to perform anoxic-reduction of nitrate, nitrite, and nitrous oxide to nitrogen.
Rhizobium hainanense is a Gram negative root nodule bacteria. Strain CCBAU 57015 (166) is the type strain.
Zoogloea caeni is a gram-negative, catalase and oxidase-positiv, facultatively aerobic, nitrogen-fixing, rod-shaped motile bacterium with a polar flagellum from the genus of Zoogloea which was isolated from activated sludge of a domestic wastewater treatment plant in Korea.
Acinetobacter nectaris is a gram-negative, oxidase-negative, catalase-positive, strictly aerobic nonmotile bacterium from the genus Acinetobacter isolated from floral nectar pollinated by Mediterranean insects in the Doñana National Park in the Huelva Province in Spain. Bacterial communities, including microbes identified as A. nectaris are closely associated with plant communities; other strains of bacteria have been found in environments that mother bees visit. This bacterium was first characterized in 2013.
Devosia neptuniae is a nitrogen-fixing bacteria that nodulates Neptunia natans. It is Gram-negative, strictly aerobic short rod-shaped and motile by a subpolar flagellum. The type strain of D. neptuniae is LMG 21357T.
Micromonospora gifhornensis is a Gram-positive bacterium from the genus Micromonospora. It is Gram-positive, aerobic and spore-forming, with type strain HR1-2T.
Lentibacillus salicampi is a moderately halophilic bacterium, the type species of its genus. It is Gram-variable, aerobic, endospore-forming and rod-shaped, with type strain SF-20(T).
Microvirgula is a Gram-negative bacteria genus from the family of Neisseriaceae. Up to now there is only one species of this genus known.
Aquaspirillum dispar is a species of Aquaspirillum that is also known as Microvirgula aerodenitrificans Patureau.
Acidithrix ferrooxidans is a heterotrophic, acidophilic and Gram-positive bacterium from the genus of Acidithrix. The type strain of this species, A. ferrooxidans Py-F3 was isolated from an acidic stream draining from a copper mine in Wales. This species grows in a variety of acidic environments such as streams, mines or geothermal sites. Mine lakes with a redoxcline support growth with ferrous iron as the electron donor. A. ferrooxidans grows rapidly in macroscopic streamer, producing greater cell densities than other streamer-forming microbes. Use in a bioreactors to remediate mine waste has been proposed due to cell densities and rapid oxidation of ferrous iron oxidation in acidic mine drainage. Exopolysaccharide production during metal substrate metabolism, such as iron oxidation helps to prevent cell encrustation by minerals.
Nitrospinae is a bacterial phylum. Despite only few described species, members of this phylum are major nitrite-oxidizing bacteria in surface waters in oceans. By oxidation of nitrite to nitrate they are important in the process of nitrification in marine environments.
Alkalihalobacillus is a genus of gram-positive or gram-variable rod-shaped bacteria in the family Bacillaceae from the order Bacillales. The type species of this genus is Alkalihalobacillus alcalophilus.
References
- ↑ LPSN lpsn.dsmz.de
- ↑ Patureau, D.; Godon, J.-J.; Dabert, P.; Bouchez, T.; Bernet, N.; Delgenes, J. P.; Moletta, R. (1998). "Microvirgula aerodenitrificans gen. nov., sp. nov., a new Gram-negative bacterium exhibiting co-respiration of oxygen and nitrogen oxides up to oxygen-saturated conditions". International Journal of Systematic Bacteriology. 48 (3): 775–782. doi: 10.1099/00207713-48-3-775 . ISSN 0020-7713. PMID 9734031.
