Isolation and characterization of an Enterococcus strain from Tibetan alpine meadow soil

Abstract:

Abstract:［Objective］We studied the physiological，biochemical properties and metabolism of Enterococcus strain CJ-1 from high-altitude soil in Namtso，Tibet． ［Methods］Strain CJ-1T was isolated from the soil of Namtso alpine meadow soil by Hungate anaerobic technique． Through physiological，biochemical and phylogenetic analysis，we identified the strain CJ-1. ［Results］Strain CJ-1 was Gram-positive and facultative anaerobe，1－1.5μm in diameter． CJ-1T was atrichia nonmotile cocci，and always occurred in pairs． CJ-1T occurred in the presence of 0%－7% NaCl (optimum at 5%)，pH 5.0－8.5 (optimum 7.0) and temperature between 10℃ and 50℃ (optimum at 25℃)．CJ-1 could metabolize many carbon sources including cellobiose，melezitose and ribose． Metabolites of cellobiose were lactic acid，acetic acid，propionic acid，butyrate，CO2，and little H2 ． The mol% G + C content of the genomic DNA was 39.2 mol%．16S rRNA gene sequence analysis of the above strain showed the highest similarity of 95. 9% with its closest phylogenetic neighbor Enterococcus aquimarinus． The strain can degrade cellobiose which act as intermediate metabolites in the methane fermentation process． ［Conclusion］CJ-1T can degrade cellobiose． CJ-1T represents a novel species in the genus Enterococcus．