TAXONOMY: cellular organisms -> Bacteria -> Proteobacteria -> Betaproteobacteria -> Burkholderiales -> Oxalobacteraceae -> Oxalobacter
'Oxalobacter' is a genus of bacteria in the Oxalobacteraceae family. The species are chemoorganotroph and strictly anaerobic.Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual of Systematic Bacteriology, Volume Two: The Proteobacteria, Part C: The Alpha-, Beta-, Delta-, and Epsilonproteobacteria. New York, New York: Springer. ISBN 978-0-387-24145- 6. They are found in rumens of animals like cattle and in fecal of other animals and humans. Some are marine and some have been isolated from freshwater.
Straight or curved to vibrioid, Gram-negative, nonsporeforming rods 0.4–0.6 × 1.0–2.5 μm in length. Flagella may be present or absent. Strictly anaerobic. Chemoorganotroph. Oxalate is used as the major carbon and energy source. Oxamate may also be used, but neither carbohydrates nor any of a wide variety of other compounds will replace oxalate as the growth substrate. Acetate is assimilated for cell synthesis and is required by some, and perhaps by all, strains. Oxalate utilization is accompanied by alkalization of the medium, and formate is produced in approximately equimolar proportions to the amount of oxalate metabolized. Strains have been isolated from the rumens of cattle and sheep, from cecal and fecal samples from humans, guinea pigs, swine, domestic and wild rats, and from freshwater lake and marine sediments. It is probable that these bacteria colonize many other anaerobic habitats. Oxalobacter is currently classified in the class Betaproteobacteria, the order Burkholderiales, and the family Oxalobacteraceae. The mol% G + C of the DNA is: 48–52. Type species: Oxalobacter formigenes.
This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072] Mammals lack the ability to detoxify oxalate, relying instead on microbial biotransformation. Three microbial enzymes are known to participate in the catabolism of oxalate: an oxalate: formate antiporter, which allows oxalate to enter the bacterial cell; formyl-CoA transferase, which converts oxalate to oxalyl-CoA; and oxalyl-CoA decarboxylase, which yields formyl-CoA. Oxalobacter is one of the key bacteria responsible for this reaction: (a) it can use oxalate as a sole carbon source; (b) lack of O. formigenes is associated with increased risk of hyperoxaluria and kidney stones ; and (c) administration of O. formigenes reduces urinary oxalate concentrations. Decreased in metabolic disorders.