Research progress on antimicrobial activities of sophorolipids and their synergistic effects with other antimicrobial substances北大核心CSCD

Sophorolipids (SLs), secondary metabolites of non-pathogenic yeasts, are glycolipid biosurfactants with wide applications. Research on the pharmaceutical activities of sophorolipids is important. In recent years, an increasing number of researchers have been interested in the antimicrobial activity of sophorolipids. In this study, the effects of sophorolipids on bacteria, fungi, and their biofilms were reviewed. Sophorolipids cause greater damage and better inhibition of gram-positive bacteria, and lactonic sophorolipids show stronger effects than acid sophorolipids. In addition, sophorolipids can disperse and destroy resistant biofilms, which are difficult to handle. Second, the synergistic effects of sophorolipids in combination with commonly used antibiotics and antimicrobial materials were reviewed. When sophorolipids and antibiotics are used together, the effective dosage of the antibiotics is significantly reduced. Sophorolipids can enhance the antimicrobial effects when used to synthesize or coat antimicrobial materials. Finally, we investigated the problems and development of the antimicrobial activities of sophorolipids, further expansion of the antimicrobial spectrum of sophorolipids, in-depth analysis of mechanisms of antimicrobial and synergistic effects, development and modification of new sophorolipids, and exploration of the water-solubility of sophorolipids. © 2022 Authors. All rights reserved.     

石油降解菌的降解特性研究

以0#柴油为唯一碳源,对石油降解菌DSP菌的生长、疏水性、产表面活性剂、脱氢酶活性及降解能力进行研究。结果表明:DSP菌在生长过程中可产生糖脂类生物表面活性剂,对石油烃的降解有很好的促进作用,其脱氢酶活性与降解率有较好的相关性。当土壤中柴油含量为10%时,利用DSP菌经过40d的处理(30℃,pH值为6),油含量下降到1.82%,降解率最高可达65.4%。     

铜绿假单胞菌S6分泌的生物表面活性剂特性

研究了1株铜绿假单胞菌S6(Pseudomonas aeruginosa S6)分泌的生物表面活性剂的理化性质.该生物表面活性剂的临界胶束浓度为50mg·L-1,此时其表面张力为29.3mN·m-1.pH值对S6产表面活性剂有一定影响,在中性及弱碱性条件下,S6长势较好且表面活性剂表面张力较低.该生物表面活性剂对菲具有非常明显的增溶效应,使水中菲的溶解度增加了约23倍.原油的加入有利于S6产表面活性物质.与原油的相互作用说明该生物表面活性剂能够乳化原油且维持乳化液稳定性于80%以上;原油浓度为6%～8%时,能达到最佳乳化效果.HPLC-ESI-MS分析检出该生物表面活性剂含有13种鼠李糖脂同系物.     

产表面活性剂解烃菌的筛选及其降解条件研究

以原油为唯一碳源和能源,从新疆克拉玛依油田土壤中筛选出1株能产生物表面活性剂的高效解烃菌XJBM,经形态观察、生理生化特征和Biolog分析,初步鉴定该菌为铜绿假单胞菌(Pseudomonas Aeruginosa)。薄层色谱分析结果表明,XJBM产糖脂类生物表面活性剂,在最适发酵条件下,生物表面活性剂的产量可达2.25 g/L,可将发酵液表面张力从68.20 m N/m降低到32.50 m N/m,乳化指数(E24)达到81.8%。采用单因素试验对影响XJBM降解率的因素进行了研究,得出最适降解条件为p H 7.5,温度30℃,盐浓度5 g/L,接种量10%。在此条件下,菌株对1%石油烃的7d降解率为63.78%。