烃降解菌株T7-2产生的生物乳化剂和其.doc

烃降解菌株T7-2产生的生物乳化剂及其理化性质研究 李 丹 黄 磊 李国强 李召雨 马 挺 梁凤来* 刘如林 (南开大学生命科学学院 天津市微生物功能基因组学重点实验室 分子微生物学与技术教育部重点实验室 天津 300071) 摘 要: 从石油污染海域海底泥中筛选到的1株低温石油烃降解菌, 经鉴定为红平红球菌(Rhodococcus erythropolis), 命名为T7-2。该菌株能以十六烷为碳源代谢产生一种对柴油等烃类具良好乳化作用的生物乳化剂。研究表明, 该乳化剂主要由糖类、脂类和蛋白质组成, 其比例为55.43:31.24:12.65。进一步研究证实, 该乳化剂糖类的单糖组成为甘露糖和鼠李糖; 脂类由十碳、十二碳、十六碳及十八碳脂肪酸组成; 蛋白质由16种氨基酸构成。本文还对乳化剂的理化性质进行了分析, 发现它是一种性能稳定、乳化效率高、适应范围较为广泛的生物乳化剂, 对海洋污染生物修复及石油开采都具有潜在的应用价值。 关键词: 生物乳化剂, 红平红球菌, 生物修复, 烃降解菌 Study on the Bioemulsifier Produced by a Hydrocarbon-degrading Strain T7-2 and Its Physic-chemical Properties LI Dan HUANG Lei LI Guo-Qiang LI Zhao-Yu MA Ting LIANG Feng-Lai* LIU Ru-Lin (College of Life Sciences, Nankai University, Tianjin Key Laboratory of Microbial Functional Genomics, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071) Abstract: A low-temperature hydrocarbon-degrading strain T7-2, isolated from sea-mud of Bohai polluted area and identified as Rhodococcus erythropolis, was found to produce an extracellular, nondialyzable emulsifying agent (referred to as bioemulsifier) when grew with hexadecane as carbon source. The results showed that, this bioemulsifier which could remarkably emulsify hydrocarbons such as diesel oil, is consisted of three parts?carbohydrates, lipids and proteins, the proportion of which was 55.43:31.24:12.65. The monosaccharide compositions were identified as mannose and rhamnose; the lipid compositions included decanoic acid, lauric acid, hexadecanoic acid and stearic acid, and the protein constituents were composed of sixteen amino acids. Besides, according to the study of the physic-chemical properties of the bioemulsifier, it possesses the obvious advantages of character stability, high function efficiency and wide adaptation range, therefore this bioemulsifier is believed to have extensive application values for bioremediation of marine oil pollution, petroleum exploitation and etc. Keywords: Bioemulsifier, Rhodococ