Characterization of Halanaerocella petrolearia gen. nov., sp. nov., a new anaerobic moderately halophilic fermentative bacterium isolated from a deep subsurface hypersaline oil reservoir

摘要

An anaerobic, halophilic, and fermentative bacterium, strain S200 ~T, was isolated from a core sample of a deep hypersaline oil reservoir. Cells were rod-shaped, non-motile, and stained Gram-positive. It grew at NaCl concentrations ranging from 6 to 26% (w/v), with optimal growth at 15% (w/v) NaCl, and at temperatures between 25 and 47°C with an optimum at 40–45°C. The optimum pH was 7.3 (range 6.2–8.8; no growth at pH 5.8 and pH 9). The doubling time in optimized growth conditions was 3.5 h. Strain S200 ~T used exclusively carbohydrates as carbon and energy sources. The end products of glucose degradation were lactate, formate, ethanol, acetate, H _2, and CO _2. The predominant cellular fatty acids were non-branched fatty acids C _(16:1), C _(16:0), and C _(14:0). The G + C mole% of the DNA was 32.7%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain S200 ~T formed a distinct lineage within the family Halobacteroidaceae, order Halanaerobiales, and was most closely related to Halanaerobaculum tunisiense DSM 19997 ~T and Halobacteroides halobius DSM 5150 ~T, with sequence similarity of 92.3 and 91.9%, respectively. On the basis of its physiological and genotypic properties, strain S200 ~T is proposed to be assigned to a novel species of a novel genus, for which the name Halanaerocella petrolearia is proposed. The type strain of Halanaerocella petrolearia is strain S200 ~T (=DSM 22693 ~T = JCM 16358 ~T).