Methanoplanus petrolearius sp nov, a novel methanogenic bacterium from an oil-producing well

A disc-shaped methanogenic bacterium designated strain SEER 4847(T) (T = type strain) was isolated from a sample collected from an African offshore oil field. Strain SEER 4847(T) was non-motile, had a G+C content of 50 mol% and produced methane from H-2+CO2, formate, and CO2 + propanol. Strain SEER 4847(T) grew optimally at 37 degrees C; no growth was observed at 25 degrees C or 45 degrees C. It grew in the presence of up to 50 g/l NaCl; 10-30 g/l was required for optimal growth. The optimum pH for growth was 7.0. Doubling time was about 10 h under optimal conditions. Based on 16S rRNA sequence analysis, the isolate was identified as a new species of the genus Methanoplanus and designated Methanoplanus petrolearius sp. nov. The type strain is SEER 4847(T) (= OCM 486).