非酿酒酵母菌的分离鉴定及产酯关键酶活性的研究

采用传统培养分离法从新疆葡萄表皮分离酵母菌，结合形态观察及WL培养基鉴定，选取代表性菌株进行分子生物学鉴定，并测定筛选菌株的产酯含量及产酯关键酶活性。结果表明，共分离出72株酵母菌株，筛选出33株代表性菌株，其中非酿酒酵母31株，归属于10个属，分别为红酵母属（Rhodotorula）、隐球酵母属（Cryptococcus）、有孢圆酵母属（Torulaspora）、克鲁维酵母属（Kluyveromyces）、有孢汉生酵母菌属（Hanseniaspora）、洛德酵母属（Lodderomyces）、梅奇酵母属（Metschnikowia）、棒孢酵母属（Clavispora）、毕赤酵母属（Pichia）和锁掷酵母属（Sporidiobolus），且Rhodotorula（16.13%）、Hanseniaspora（16.13%）和Pichia（19.35%）为主要非酿酒酵母。非酿酒酵母中Torulaspora XM2（5.22 g/L）、Pichia K3（4.91 g/L）、Hanseniaspora HE3（4.63 g/L）和Pichia ML3（4.57 g/L）总酯含量较高。通过对其产酯关键酶活性的测定推测乙酸酯水解酶及醇乙酰基转移酶对酯类物质的生成可能有极大地影响。

Isolation and identification of non-Saccharomyces cerevisiae and key enzyme activity for ester production

Yeasts were isolated from grape skin in Xinjiang by traditional culture and isolation methods, combined with morphological observation and WL medium identification, and the representative strains were selected and identified by molecular biology. The ester yield and key enzyme activity of the selected strains were determined. The results showed that a total of 72 yeast strains were isolated and 33 representative strains were screened. Among them, 31 strains of non-Saccharomyces cerevisiae belonged to 10 genera, namely Rhodotorula, Cryptococcus, Torulaspora, Kluyveromyces, Hanseniaspora, Lodderomyces, Metschnikowia, Clavispora, Pichia and Sporidiobolus; and Rhodotorula (16.13%), Hanseniaspora (16.13%) and Pichia (19.35%) were the main non-Saccharomyces cerevisiae strains. The total ester contents of Torulaspora XM2 (5.22 g/L), Pichia K3 (4.91 g/L), Hanseniapora HE3 (4.63 g/L) and Pichia ML3 (4.57 g/L) in non- Saccharomyces cerevisiae strains was higher. It was speculated that acetate hydrolase and alcohol acetyltransferase may have a great influence on the esters formation by measuring the key enzyme activities.