1株耐高温高盐生香酵母的选育及特性分析

Screening and characterization of aroma yeast with thermo-tolerant and salt-tolerance

以豆瓣酱为材料筛选出86株产酯菌,以期从中得到1株耐高温高盐生香酵母菌。通过耐高温、耐高盐和产酯能力试验,获得1株耐高温高盐生香酵母菌PX-8,其在温度高达40℃和Na Cl质量浓度高达180 g/L的条件下能正常生长。经过26S r DNA鉴定,确定菌株PX-8为鲁氏结合酵母(Zygosaccharomyces rouxii)。经过产酯发酵条件优化试验,菌株PX-8的最佳产酯培养条件为:葡萄糖80 g/L,酵母粉40 g/L,KH_2PO_41 g/L,Mg SO_40.5g/L,p H 6.0,32℃,150 r/min,发酵培养6 d,总酯产量高达2.615 g/L;在高温高盐条件下(发酵培养温度为40℃,盐质量浓度为180 g/L),发酵培养21 d,总酯产量可达1.518 g/L。

To obtain an aroma yeast strain with thermo-tolerance and salt-tolerance,86 strains was isolated from bean paste. Through thermo-tolerance test,salt-tolerance test and determination of yield of este,strain PX-8 was screened out because it could grow normally at temperature up to 40 ℃ and Na Cl concentration up to 180 g/L. According to 26 S r DNA sequence analysis,strain PX-8 was identified as Zygosaccharomyces rouxii. The optimum conditions for production of ester with strain PX-8 were fermentation in medium cotaining glucose 80 g/L,yeast extract 40 g/L,KH_2PO_41 g/L,Mg SO_40. 5 g/L,at p H6. 0,32 ℃,with 150 r/min shaking for 6 days. The yield of total ester was up to 2. 615 g/L. After fermentation under high temperature and high salt conditions（ fermentation temperature was 40 ℃,Na Cl concentration was 180 g/L） for 21 days,the yield of total ester could reach 1. 518 g/L. This study could provide useful reference for germplasm resources in the flavor promotion of fermented food such as soy sauce.