生物表面活性剂对红球菌SY095降解正十六烷及细胞表面性质的影响

Effects of Biosurfactant Produced by Rhodococcus SY095 on the Biodegradation of n-Hexadecane and the Cell Surface Hydrophobicity

目的:研究红球菌SY095产生物表面活性剂对正十六烷的溶解性、微生物降解正十六烷的效率、菌体生长及菌体表面疏水性的影响。方法:测定添加不同生物表面活性剂的降解体系中菌体生物量、细胞表面疏水性、正十六烷含量的变化。结果:生物表面活性剂对疏水性底物正十六烷具有很强的增溶作用,可以显著提高正十六烷的表观溶解度;生物表面活性剂对正十六烷的生物降解具有促进作用,添加量为100 mg/L时,96 h正十六烷去除率达93.32%;生物表面活性剂能明显促进红球菌SY095生长,添加量为300 mg/L时,菌株32 h生物量为未添加生物表面活性剂对照组的2.7倍;生物表面活性剂还能引起红球菌SY095菌体表面疏水性明显增大,添加量为25 mg/L时,菌株对数生长期BATH值达66.94%,高于未添加生物表面活性剂对照组的42.99%。结论:生物表面活性剂可以增加菌体的表面疏水性,促进微生物对正十六烷的生物降解。

Objective： To study the effects of biosurfactant produced by Rhodococcus SY095 on the biodegradation efficiency of n-hexadecane, the solubility of n-hexadecane, the growth of bacteria and the cell surface hydrophobicity. Methods： The cell biomass of Rhodococcus SY095, cell surface hydrophobicity and n-hexadecane content in different biosurfactant degradation systems were determined. Results： The results showed that the solubility of n-hexadecane was enhanced significantly by biosurfactant. The degradation of n-hexadecane was accelerated with biosurfactant. With 100 mg/L of biosurfactant, the average degradation rate of n-hexadecane in 96 h could reach 93.32%. The biosurfactant could promote the growth of Rhodococcus SY095. Compared with the control group, the biomass of Rhodococcus SY095 increased 2.7 times in 32 h by adding 300 mg/L biosurfactant. The cell surface hydrophobicity of Rhodococcus SY095 was enhanced significantly also by adding biosurfactant. The cell surface hydrophobicity reached 66.94% in logarithmic growth phase by adding 25 mg/L biosurfactant, while that the absence of biosurfaetant was only 42.99%. Conclusion： The biosurfactants could enhance the cell surfaces hydro- phobieity of SY095 and promoted the biodegradation of the n-hexadecane.