产碱性脂肪酶热带假丝酵母LYSC-3的筛选、鉴定及发酵条件的优化

Screening,identification of Candida tropicalis LYSC-3 excreting lipase and optimization of fermenting conditions

以橄榄油为唯一碳源,以溴钾酚紫为显色剂,采用琼脂平板法从富含油脂的土壤中筛选到一株产碱性脂肪酶野生型菌株LYSC-3。经形态学、生理生化和分子生物学的鉴定,确定菌株LYSC-3为热带假丝酵母(Candida tropicalis)。经发酵条件优化,菌株LYSC-3的最佳产碱性脂肪酶的发酵条件为:橄榄油10g·L-1、蛋白胨5g·L-1、蔗糖20g·L-1、(NH4)2SO40.5g·L-1、MgSO4·7H2O0.2g·L-1,K2HPO40.2g·L-1,pH8.0,35℃,150r·min-1摇床振荡培养3d,获得碱性脂肪酶最高酶活力达38.6U·mL-1。

A strain of LYSC 3 was screened by bromocresol purple media agar plate from oil rich soil. LYSC 3 was identified as Candida tropicalis by methods of morphology,physiology and molecular biology. Fermentation conditions were also optimized through single factor. Results indicated that lipase activity reached 38. 6U·mL-1 when Candida tropicalis LYSC 3 was cultured on the media of olive oil 10g·L-1,peptone 5g·L-1,sugar 20g·L-1,（NH4）2SO4 0. 5g·L-1,MgSO4·7H2O 0. 2g·L-1,K2HPO4 0. 2g·L-1,pH8. 0,rotated at 150r·min-1 at 35℃ for 3d.