产氨基甲酸乙酯降解酶酵母菌的筛选鉴定及发酵条件优化

Screening and Identification of Yeasts Producing EC-Degrading Enzymes and Optimization of Fermentation Conditions

采用选择性培养基,从36株酵母菌中分离纯化得到4株(Y4、Y9、Y13、N6)产氨基甲酸乙酯降解酶酵母菌,通过ITS序列比对,均属于Pichia kudriavzevii。通过单因素试验和正交试验,对Y13菌株产EC水解酶的发酵条件进行优化。结果表明:最优条件是以10g/L麦芽糖为碳源;以30g/L酵母浸粉为氮源;接种量为6%;培养基中EC的底物浓度为5.00%,装液量为20%,初始pH为6,培养温度为28℃,培养时间为120h。

Four strains(Y4,Y9,Y13,N6)of yeasts producing EC-degrading enzymes are isolated and purified from 36 strains of yeasts by selective medium.The ITS sequence alignments belong to Pichia kudriavzevii.The fermentation conditions of EC hydrolase produced by Y13 strain are optimized by single factor test and orthogonal test.The results show that the optimum conditions are 10 g/L maltose as the carbon source;30 g/L yeast extract as the nitrogen source;the inoculum size is 6%;the substrate concentration of EC in the medium is 5.00%,the liquid volume is 20%,the initial pH is 6,the culture temperature is 28℃,and the culture time is 120 h.