Clostridium weizhouense sp. nov., an anaerobic bacterium isolated from activated sludge of petroleum wastewater

A Gram-stain-positive, anaerobic, spore-forming, rod-shaped (0.4-0.6 mu mx2.5-3.2 mu m), flagellated bacterium, designated strain YB-6(T), was isolated from activated sludge of an anaerobic tank at Weizhou marine oil mining wastewater treatment plant in Beihai. Guangxi, PR China. The culture conditions were 25-45 degrees C (optimum, 37 degrees C), pH 4-12 (pH 7.0) and NaCl concentration of 0-7% w/v (0%). Strain YB-6(T) grew slowly in petroleum wastewater and removed 68.2% of the total organic carbon in petroleum wastewater within 10 days. Concentrations of naphthalene. anthracene and phenanthrene at an initial concentration of 50 mg l(-1) were reduced by 32.8. 40.4 and 14.6%, respectively, after 7days. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain YB-6(T) belongs to Clostridium cluster I and is most closely related to Clostridium uliginosum CK55(T) (98.5% similarity). The genome size of strain YB-6(T) was 3.96 Mb, and the G+C content was 26.5 mol%. The average nucleotide identity value between strain YB-6(T) and C. uliginosum CK55(T) was 81.9%. The major fatty acids in strain YB-6(T) were C-14:0 FAME, C-16:0 FAME and summed feature 4 (unknown 14.762 and/or C-15:2 FAME). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine. five unidentified aminophospholipids, one unidentified glycolipid and one unidentified aminolipid. Diaminopimelic acid was not detected in the strain YB-6(T) cell walls. Whole-cell sugars mainly consisted of ribose and galactose. Based on the results of phenotypic and genotypic analyses, strain YB-6(T) represents a novel species of the genus Clostridium. for which the name Clostridium weizhouense sp. nov. is proposed. The type strain is YB-6(T) (=GDMCC 1.2529(T) =JCM 34754(T)).

Automated summary

Strain YB-6(T) is a Gram-stain-positive, anaerobic, spore-forming, rod-shaped bacterium that was isolated from activated sludge of an anaerobic tank at Weizhou marine oil mining wastewater treatment plant in Beihai, Guangxi, PR China. It grows at a temperature range of 25-45°C (optimum, 37°C), pH range of 4-12 (pH 7.0) and NaCl concentration of 0-7% w/v (0%). The strain can grow slowly in petroleum wastewater and remove organic carbon. Phylogenetic analysis indicates that strain YB-6(T) belongs to Clostridium cluster I and is closely related to Clostridium uliginosum CK55(T).