Identification and bio-corrosion behavior of Thermoanaerobacter CF1, a thiosulfate reducing bacterium isolated from Dagang oil field

摘要

A slightly curved rod strictly anaerobic, thermophilic bacterium was isolated from Dagang oil field, China. Its fundamental physiology and bio-corrosion characteristic were characterized. The growth of strain CF1 occurred at 45 to 78°C (optimum 60°C), pH 5.0 to 9.5 (optimum 7.1). The doubling time under optimal conditions was 45 min. Substrates that could be used included D-cellobiose, fructose, glucose,?maltose,?mannose,trehalose, melezitose, raffinose, ribose, sucrose, xylose and starch. 16S rRNA gene sequence analysis indicated that the isolate was most closely related toThermoanaerobacter uzonensis?(99.2%). The G+C content of the genomic DNA of strain CF1 was 33.5 mol%. The major cellular fatty acid contents were 14 : 0 (2.5%), 15 : 0 (65.8%), 16 : 0 (8.6%), 15-methyl 17:0 (8.1%), 14-methyl 17:0 (7.4%), 18 : 1v9c (1.7%) and 18 : 0 (4.8%). The strain reduced up to 1 M thiosulfate to elemental sulfur without sulfide formation. In the presence of thiosulfate, electrochemical method, weight loss and surface analysis showed the corrosion behavior of the isolate. A slight change of corrosion current was detected through electrochemical method. Elemental sulfur was found on the surface of the carbon steel, with less weight loss in the cultivation system.?Key?words:?Thiosulfate reduction, element sulfur, bio-corrosion, carbon steel.