Pseudomonas denitrificans: Difference between revisions
| Line 21: | Line 21: | ||
=4. Cell structure= | =4. Cell structure= | ||
Pseudomonas denitrificans is a Gram-negative, aerobic, rod-shaped bacteria. The optimum growth temperature for P. denitrificans is 25°C.14 P. denitrificans colonies do not fluoresce, and they acquire a smooth off-white/tan color appearance. The cell sizes ranges around 1.05 x 0.8 µm, and can be composed of up to 48% lipids, depending on the strain.14 Further information of cell structure is still not clearly known for this particular Pseudomonas, and research studies are ongoing. | |||
=5. Metabolic processes= | =5. Metabolic processes= | ||
Pseudomonas denitrificans is one of the few microorganisms that can synthesize Vitamin B12 de novo under aerobic conditions.2 Vitamin B12, also known as cyanocobalamin, is an essential vitamin for the proper function of the animal nervous system1, and it is used as a coenzyme in many metabolic pathways, such as the conversion of l-methylmalonyl-coenzyme A (CoA) to succinyl-CoA, catalyzed by methylmalonyl-CoA mutase (MCM).15 Notably, deficiency has been associated with ataxia, spasticity, muscle weakness, dementia, psychosis, and Alzheimer’s disease.4 | Pseudomonas denitrificans is one of the few microorganisms that can synthesize Vitamin B12 de novo under aerobic conditions.2 Vitamin B12, also known as cyanocobalamin, is an essential vitamin for the proper function of the animal nervous system1, and it is used as a coenzyme in many metabolic pathways, such as the conversion of l-methylmalonyl-coenzyme A (CoA) to succinyl-CoA, catalyzed by methylmalonyl-CoA mutase (MCM).15 Notably, deficiency has been associated with ataxia, spasticity, muscle weakness, dementia, psychosis, and Alzheimer’s disease.4 | ||
Revision as of 21:47, 28 November 2018
1. Classification
a. Higher order taxa
Domain; Phylum; Class; Order; Family; Genus Include this section if your Wiki page focuses on a specific taxon/group of organisms
2. Description and significance
Pseudomonas denitrificans is a polar flagellated, rod-shaped, Gram-negative, aerobic, heterotrophic bacteria species with the ability to produce vitamin B12.1 P. denitrificans is one of the few microorganisms that can synthesize vitamin B12 under aerobic conditions.2 As the name suggests, P. denitrificans is also capable of performing denitrification as a part of nitrogen cycle, a process in which nitrate is reduced into nitrogen gas (N2).2
Despite the enormous knowledge known about of P. denitrificans, there is still a lot of information unknown. Its cytochrome cc’ protein, which is found in the mitochondria, is essential in the electron transport chain, but yet to be studied in depth for its relationship to similar proteins in photosynthetic bacteria.3 The evolutionary implications of conserved genes encoding for vitamin B12 production may yet reveal insights into the origin of metabolism, since the pathway is thought to have developed to support fermentation processes, but as of yet not conclusively proven.4 P. denitrificans’ medical and environmental significance, in terms of its industrial use for vitamin B12 production and potential nitrate toxicity or wastewater treatment applications, is also unavailable (Xia, Cusanovich, Rodionov, Martens, Paranova-Mancheva).(3-7)
Studying P. denitrificans can offer valuable insights because it is believed to be phylogenetically ancient, and so an opportunity for understanding metabolic evolution.4 Its vitamin B12 production can provide nutritional services to many life forms.4 In terms of more fundamental significance, its chemotrophic use of the cytochrome cc’ heme contrasts with purple bacteria photosynthetic use of a structurally and genetically similar protein, which indicates that it exists at a critical juncture in ATP production evolution.3 Its supplementation of oxidative phosphorylation with denitrification provides insights into how it fulfills and maintains a niche across fluctuating O and N levels in environments.8
Vitamin B12 production may also provide health services to humans, since it is a precursor to methionine synthase, responsible for regeneration of essential amino acids in humans and (R)-methylmalonyl-CoA, responsible for fatty acid catabolism.4 P. denitrificans may also be engineered to produce other commercial compounds, such as 3-hydroxypropionic acid.9.Its denitrification abilities have critical potential in wastewater management.7 Pathologically speaking, P. denitrificans may opportunistically cause meningitis in humans.10 P. denitrificans may also colonize the intestines of fish.11
3. Genome structure
Pseudomonas denitrificans has been assigned to the bacteria domain, Proteobacteria phylum, Gammaproteobacteria class, Pseudomonadaceae family, and Pseudomonas Pertucinogena group based on 16S rRNA sequence (Anzai, Tran).(12-13)
P. denitrificans ATCC 13867 genome consists of single circular chromosome with a genome size of 5,696,307 bps with 65.2% Guanine + Cytosine content.1 Its genome has 2,567 operons and 5,059 protein-encoding genes, where 59.56% of proteins are characterized as cytoplasmic and 19.41% non-cytoplasmic, while the the remaining percentage is still unknown.1 Its genome has genes for all 20 amino acids, with 63 transfer RNAs. It also contains 1,279 ribosome-binding sites, and 816 transcription terminators.1
In addition, P. denitrificans genome contains genes encoding 26 enzymes that are involved in the biosynthesis of vitamin B12, where the genes are divided in two different clusters on the chromosome.1 The first and second clusters encode genes that are involved in the vitamin B12 biosynthesis pathway.1 Additionally, P. denitrificans genome contains methionine synthase gene, a protein that catalyzes the synthesis of L-methionine, an essential amino acid that uses vitamin B12 as a cofactor.1
4. Cell structure
Pseudomonas denitrificans is a Gram-negative, aerobic, rod-shaped bacteria. The optimum growth temperature for P. denitrificans is 25°C.14 P. denitrificans colonies do not fluoresce, and they acquire a smooth off-white/tan color appearance. The cell sizes ranges around 1.05 x 0.8 µm, and can be composed of up to 48% lipids, depending on the strain.14 Further information of cell structure is still not clearly known for this particular Pseudomonas, and research studies are ongoing.
5. Metabolic processes
Pseudomonas denitrificans is one of the few microorganisms that can synthesize Vitamin B12 de novo under aerobic conditions.2 Vitamin B12, also known as cyanocobalamin, is an essential vitamin for the proper function of the animal nervous system1, and it is used as a coenzyme in many metabolic pathways, such as the conversion of l-methylmalonyl-coenzyme A (CoA) to succinyl-CoA, catalyzed by methylmalonyl-CoA mutase (MCM).15 Notably, deficiency has been associated with ataxia, spasticity, muscle weakness, dementia, psychosis, and Alzheimer’s disease.4
Because P. denitrificans is is an overproducer of Vitamin B12, it has been used in large scale industrial production, and engineered to produce even higher yields via fermentation.16 In P. denitrificans, Vitamin B12 is synthesized aerobically, requiring oxygen to promote ring-contraction, and requiring approximately 30 different enzymes.16
6. Ecology
Habitat; symbiosis; contributions to the environment.
7. Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
8. Current Research
Include information about how this microbe (or related microbes) are currently being studied and for what purpose
9. References
It is required that you add at least five primary research articles (in same format as the sample reference below) that corresponds to the info that you added to this page. [Sample reference] Faller, A., and Schleifer, K. "Modified Oxidase and Benzidine Tests for Separation of Staphylococci from Micrococci". Journal of Clinical Microbiology. 1981. Volume 13. p. 1031-1035.
