Haddad Namir I A, Wang Ji, Mu Bozhong
State Key laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai 200237, China.
Protein Pept Lett. 2009;16(1):7-13. doi: 10.2174/092986609787049358.
A biosurfactant-producing strain was isolated from the production water of an oil-field and was identified as Bacillus subtilis HOB2 by 16S rRNA gene sequencing. The production of biosurfactant by Bacillus subtilis HOB2 has been investigated using different carbon and nitrogen sources, under thermophilic and mesophilic conditions. The strain was able to grow and to produce surfactant, reducing the surface tension of medium to 27 mN/m on sucrose, and 28 mN/m on glucose after 24 h of cultivation. The strain was able to produce the maximum amount of biosurfactant when ammonium ions were used as nitrogen source. The surface-active compound was stable during exposure to elevate temperature (100degreesC), high salinity (25% NaCl) and a wide range of pH values (5.0-11.0). The biosurfactant was capable of forming a promising emulsification index (E(24)= 68%) with kerosene. The kinetic studies revealed that biosurfactant production is a cell growth-associated process. Preliminary chemical characterization revealed that the surfactant has a lipopeptide composition similar to surfactin as confirmed by TLC and IR analysis. Properties and characteristics of the biosurfactant produced by Bacillus subtilis HOB2 suggesting potential commercial applications, such as enhanced oil recovery, bioremediation of soil and marine environments, and food industries.
从某油田采出水中分离出一株产生物表面活性剂的菌株，通过16S rRNA基因测序鉴定为枯草芽孢杆菌HOB2。在嗜热和中温条件下，利用不同的碳源和氮源研究了枯草芽孢杆菌HOB2产生物表面活性剂的情况。该菌株能够生长并产生表面活性剂，培养24小时后，在蔗糖上可将培养基的表面张力降低至27 mN/m，在葡萄糖上可降低至28 mN/m。当以铵离子作为氮源时，该菌株能够产生最大量的生物表面活性剂。该表面活性化合物在高温（100℃）、高盐度（25% NaCl）和较宽的pH值范围（5.0 - 11.0）下都很稳定。该生物表面活性剂与煤油形成了良好的乳化指数（E(24)= 68%）。动力学研究表明，生物表面活性剂的产生是一个与细胞生长相关的过程。初步化学表征显示，经TLC和IR分析证实，该表面活性剂具有与表面活性素相似的脂肽组成。枯草芽孢杆菌HOB2产生的生物表面活性剂的性质和特征表明其具有潜在的商业应用价值，如提高原油采收率、土壤和海洋环境的生物修复以及食品工业等。
