AWWA WQTC64073

Since its first description by Ferdinand Cohn 136 years ago, C. polyspora has been known for mass developments in drinking water systems and affecting the drinking water quality. Since C. polyspora has never been cultured, its phylogenetic affiliation and physiological properties remained a secret until molecular methods revealed it to be a gammaproteobacterial methane oxidizer with a phylogenetically very unusual particulate methane monooxygenase (Stoecker et al, 2006). The results from molecular studies were supported by physiological experiments conducted with physically enriched biomass of C. polyspora from a drinking water treatment plant. The C. polyspora enrichment oxidized methane with concomitant decrease of oxygen and an increase of carbon dioxide. The methane oxidation rate at the temperature optimum of 20ºC followed a Michaelis Menten kinetic with a V_max of 1,548¿¿¿¿29 µmol CH₄ h^-1 [g_{dw biomass}]^-1 and a K_m of 3,901¿¿¿¿348 ppmv of methane. Thus, C. polyspora can be considered a low-affinity methane oxidizing bacterium. Includes 11 references.