异常威客汉姆酵母产酯酶培养基优化及发酵液香气物质分析

Optimization of esterase production medium and analysis of aromatic substances in the fermented broth by Wickerhamomyces anomalus

通过响应面法对异常威客汉姆酵母Y-1培养基组分进行优化,以达到提高产酯酶活力的目的。先通过单因素实验确定培养基适宜碳源为玉米淀粉,氮源为酵母膏和NH 4Cl,再利用Box-Behnken实验、响应面法对主要影响因素进行优化。实验结果表明:利用优化后的培养基进行发酵,测得该菌株所产酯酶活力为0.263 U/mL,是优化前的4.3倍。采用固相微萃取法(SPME)对发酵液挥发性成分进行提取,并结合气质联用仪(GC-MS)对其定量分析,检测出酯类物质共17种,相对质量分数占总高级挥发成分的86.23%,其中己酸乙酯、乙酸苯乙酯、辛酸乙酯和庚酸乙酯等乙酯类为主要成分。

Response surface methodology(RSM)was used to optimize the composition of abnormal Wickerhamomyces anomalus Y-1 medium to improve the activity of esterase production.First,the optimal carbon source of the medium was corn starch,yeast extract and NH4Cl by single factor test.Then,the main influencing factors were optimized by Box-Behnken test and response surface methodology.The experimental results showed that using the optimized medium for fermentation,the esterase activity of this strain was 0.263 U/mL that was 4.3 times higher than that before optimization.By using solid phase microextraction(SPME)to extract of fermented liquor volatile components,and combining with GC instrument(GC-MS)for the quantitative analysis,a total of 17 species of ester matters were detected with 86.23%relative content of the total high volatile component.Among them,phenyl ethyl acetate,ethyl caproate acrylic acid ethyl ester,heptanoic acid ethyl ester,and ethyl ester were the main ingredients.