生物表面活性剂生产菌的鉴定及其发酵优化和产物性质研究

Production and characterization of lipopeptide biosurfactant

由中国科学院南海海洋研究所提供的一株生物表面活性剂生产菌,经菌落、菌体形态和16S rDNA序列分析,鉴定为芽孢杆菌属,命名为Bacillus SCUT09。初步优化了该菌株的培养条件,最佳碳、氮源分别为木薯淀粉、牛肉膏,最利于Bacillus SCUT09生长和生物表面活性剂积累的条件为:NaCl 1%,pH 6.5,28℃。经薄层色谱和傅里叶红外光谱分析,该菌株代谢产生的生物表面活性剂为脂肽类物质,能将水的表面张力降到27 mN/m,临界胶束浓度为0.2 g/L。

A biosurfactant- producing bacterium SCUT09 given by South China Sea Institute of Oceanology was classified as Bacillus sp. according to its 16S rDNA sequences. The cultural conditions of the strain were primarily optimized. The optimum carbon and nitrogen source were cassava starch and beef extract, respectively. Under the conditions of 1% NaCI, pH 6.5 and 28℃, the biomass and emulsifying ability reached the maximum values. Fourier transform infrared spectroscopy and thin layer chromatography analysis revealed that SCUT09 produced lipopeptide biosurfactant in the process of metabolism. It could reduce surface tension of water to 27 mN/m, and its critical micelle concentration （CMC） was 0.2 g/L.