Isolation and identification of a thermophilic bacterium from hotsprings in Changbai Mountains

Abstract:

[Objective] We studied physiological and biochemical properties of a thermophilic bacterium isolated from hot springs in Changbai Mountain. [Methods] The strain CBS-5 (=JCM 15484) from hot springs in Changbai Mountains was isolated by plating and screening on Olive-rich medium. It was characterized by the physiological and biochemical analysis, 16S rDNA sequencing and determination of (G+C)mol% contents. [Results] The cells were Gram-positive, non-motile rods, spore-forming and generally occurred singly or in pairs. The growth temperature ranges from 48℃ to 70℃, optimum at 65℃; growth pH ranges from 6.5 to 8.5, optimum at 7.7. The strain used glucose, sucrose, maltose, lactose and rhanmose as carbon and energy sources. The G+C content of DNA was 41.9 mol%. The major cellular fatty acids were iso-C15 : 0, C16 : 0 and iso-C17 : 0, respectively representing about 24.20%, 20.45% and 17.42% of total fatty acids. The 16S rDNA sequence analysis showed that the strain belonged to the Anoxybacillus genus, for the sequence similarity was 95.1%-98.5% to other known species of Anoxybacillus. [Conclusion] Strain CBS-5 was a member of Anoxybacillus.

Key words:Thermophilic bacterium; Anoxybacillus; fatty acid profiles; 16S rDNA