产脂肪酶菌株的筛选、鉴定与产酶条件优化

以橄榄油为唯一碳源,采用平板变色圈法,从土壤中筛选到1株脂肪酶高产菌XYU-6,经生理生化试验鉴定及16S rDNA序列分析,XYU-6被鉴定为洋葱假单胞菌(Burkholderia cepacia).设计单因素试验,对其产酶条件进行优化,优化后的培养条件为:葡萄糖1.00；,蛋白胨2.00；,豆油1.00；,KH2 PO40.35；,K2 HPO4 0.15；,MgSO40.05；,初始pH值为7.0,培养温度30℃,培养48 h,酶活可达24.1U·mL-1,是优化前的1.65倍.

The Screening and Identification of a Lipase-Producing Strain and Its Culture Condition Optimization

A lipase producing strain XYU-6 was isolated from the soil by the method of flat discolor circle with olive oil as sole carbon source.XYU-6 was identified as Burkholderia cepacia by 16S rDNA sequencing and its biochemical and physiological characteristics.The optimal conditions,glucose 1.0%,peptone 2.0%,soya-bean oil 1%,KH₂PO₄ 0.35%,K₂HPO4 0.15% and MgSO₄ 0.05% were obtained through one-factor experimental design.Furthermore,the highest lipase activity 24.1 U·mLwas achieved under the optimum conditions with initial pH 7.0,culture temperature 30 ℃ and culture time 48 h.These results indicated that the lipase activity was improved 1.65 fold compared to the original conditions.