产谷胱甘肽昆虫共生酵母菌的筛选、鉴定和培养条件优化

Screening,Identification and Cultural Condition Optimization of Glutathione-Producing Insect-Symbiotic Yeast

从水黾肠道中分离并筛选到1株产还原型谷胱甘肽(GSH)的酵母菌株SM3,经初步鉴定为Candida carpophila菌。通过正交实验优化菌株产GSH的最佳培养基成分:3%蔗糖为碳源,0.2%(NH4)2SO4为无机氮源,0.8%酵母浸粉为有机氮源,K2SO40.3%,KH2PO40.6%,MgSO40.15%。单因素实验表明其较佳培养条件为:接种量15%,培养时间36 h,摇床转速200 r/min,温度32℃,pH 6.0,装液量为20/250 mL。优化后GSH产量可达159.35 mg/L,较优化前提高了105.27%。

A reduced form glutathione （GSH） producing yeast strain SM3 was isolated from the intestine of pond skater （Aquarius elongatus）, and it was identified initially as Candida carpophila. The cultural substrates for the strain to produce GSH were optimized by orthogonal experiment with the components as follows： 3% sucrose as carbon source, 0.2% （NH4）2SO4 as inorganic nitrogen source, 0. 8% yeast extract as organic nitrogen source, 0. 3% K：SO4 , 0.6% KH2PO4 , 0.15% MgSO4. The single-factor experiments showed the optimized fermentation conditions were as follow： inoculation amount at 15% , culture for 36 h, filling volume at 20/250 mL, shaking at 200 r/min, temperature and pH were at 32℃ and 6.0 respectively. The GSH yield was as high as 159.35 mg/L after the optimization, increased by 105.27% as compared with that before optimization.