酵母菌产乳化剂能力及其对含油废水降解性能的影响研究

Effects of emulsifier production and emulsification ability on biodegradation efficiency of oil-containing wastewater by different yeast strains

研究了3株酵母菌(Candida lipolytica、Candida tropicalis和Candida halophila)产乳化剂能力与废水降解性能的关系。研究结果表明,3株酵母菌在含油废水中生长良好,且均可产生乳化剂。培养5 d后,菌株Candida lipolytica和Candida tropicalis的油脂去除率达到了94%以上;培养第3天时废水溶液中的乳化剂含量最高,分别为21 g/L和34 g/L;菌体细胞产乳化剂最高量出现在培养的第1天,分别为17(ng.mL-1)/100 cfu和13.5(ng.mL-1)/100 cfu;Candida halophila产乳化剂能力较弱,溶液中乳化剂量和菌体细胞产乳化剂量最高分别为12 g/L、0.45(ng.mL-1)/100 cfu,油脂去除率最大为66%。研究表明,酵母菌株产乳化剂量及乳化能力直接影响到酵母菌对废水中油脂的降解效果。3株酵母菌对废水COD去除率均达到80%以上,差异不明显,可能与不同菌株对不同种类基质的利用效率有关。

Three yeast strains（Candida lipolytica,Candida tropicalis, Candida halophila）were employed to evaluate the relationship between their emulsifier production and emulsification ability and biodegradation capa- bility in oil-containing wastewater. The result shows that all yeast strains have a strong capability to adapt the high oily environment and produce emulsifier. After 5 days of culture, lipid removal rates of Candida lipolytica and Candida tropicalis was all up to 94% , the highest yield of emulsifier in solution were 21 g/L and 34 g/L, respectively, when cultured for 3 days; the emulsifier production by yeast cells were 17 （ng ·mL-1 ）/100 cfu and 13.5（ng · mL-1 ）/100 cfu, respectively on the first day, which were the highest during 5 day＇s culture. The emulsifier production ability of Candida halophila was weak, the highest emulsifier production in solution and produced by yeast cells were 12 g/L and 0.45 （ng·mL-1）/100 cfu, respectively; lipid removal rate was 66%. The studies show that emulsifiers production and emulsifying ability of yeast strainsdirectly affected the lipid degradation in wastewater. COD degradation rates of the three yeast strains were over 80 %. There was no significant difference. The reason may be related to different types of strains showing different substrate utilization efficiency characteristics.