一株产生生物表面活性剂的海洋细菌培养条件优化与产物特性研究

微生物代谢产生的生物表面活性剂在海洋环境污染的生物处理方面具有较大应用潜力。从青岛近岸海水中分离到一株生物表面活性剂产生菌株S-22，鉴定为球型节杆菌（Arthrobacter globiformis），通过摇瓶实验对其生长和产生生物表面活性剂的培养条件进行优化，最佳培养条件下6 h表面张力可降低至30.5 mN/m。该菌株产生生物表面活性剂的速度快，有利于大规模工业生产。综合薄层层析分析、傅立叶变换红外光谱分析和GC-MS分析，结果表明该生物表面活性剂是一种由海藻糖和两种脂肪酸（十六烷酸和9-双键十八烷酸）组成的海藻糖脂。该海藻糖脂表面活性高，临界胶束浓度为48.5 mg/L，具有良好的乳化能力，且耐盐和耐热能力较强，具有良好的应用前景。

Optimization of culture conditions of a biosurfactant-producing marine bacterium and characteristics research of its product

Microbial metabolism can produce biosurfactant, which have potential for biological treatment of marine environmental pollution. An Arthrobacter globiformis strain S-22 was isolated from the offshore seawater of Qingdao. The optimum conditions for its growth and production of biosurfactant were determined by shaking flask experiment. The surface tension decreased to 30.5 mN/m at optimum condition in 6 h. The synthesis of biosurfactant was fast in strain S-22, which was helpful for large scale industrial production. The results of TLC, FT-IR and GC-MS analyses showed that the biosurfactant was a glycolipid composed of trehalose and two fatty acids (hexadecanoic acid and 9-octadecanoic acid). The trehalose lipid, whose critical micelle concentration was as low as 48.5 mg/L, had a fine emulsification capacity with high surface-activity and strong endurance to heat and salts.