高产乙酸乙酯酵母菌的筛选、鉴定及发酵条件优化

Screening, identification and fermentation conditions optimization of high-yielding ethyl acetate yeast

该研究以产酯酵母为研究对象,通过气相色谱-质谱联用(GC-MS)技术测定菌株的乙酸乙酯产量并筛选高产乙酸乙酯的酵母菌株,通过形态学观察和分子生物学技术对其进行菌种鉴定,并以乙酸乙酯产量为响应值,通过单因素及响应面试验对其发酵条件进行优化。结果表明,筛选得到一株高产乙酸乙酯的酵母菌株P-3,乙酸乙酯产量为134.32 mg/L。菌株P-3被鉴定为库德里阿兹威毕赤酵母(Pichia kudriavzevii),其产乙酸乙酯的最佳发酵条件为:发酵温度30℃,乙醇体积分数18%,发酵时间4 d,在此条件下,乙酸乙酯产量达到281.47 mg/L,比优化前提高109.55%。

In this study,the ester-producing yeast was used as the research object,the ethyl acetate yield was determined by gas chromatography-mass spectrometry(GC-MS)technology,and the yeast strains with high ethyl acetate yield were screened.The strains were identified by morphological observation and molecular biology techniques,and the fermentation conditions were optimized by single factor and response surface experiments with the ethyl acetate yield as the response value.The results showed that a high-yielding ethyl acetate yeast strain P-3 was obtained,with an ethyl acetate yield of 134.32 mg/L.Strain P-3 was identified as Pichia kudriavzevii,and the optimal fermentation conditions for ethyl acetate production were obtained as follows:fermentation temperature 30℃,ethanol volume fraction 18%,and fermentation time 4 d.Under these conditions,the yield of ethyl acetate reached 281.47 mg/L,which was 109.55%higher than that before optimization.