【摘要】 通过耐铁实验及铁驯化实验研究耐受性黄酒酵母YS6.2.5转化铁的特性,通过摇瓶实验及发酵罐放大实验研究YS6.2.5转化铁工艺。结果表明:YS6.2.5具有较强的耐铁能力及转化铁潜力,500mL三角瓶摇瓶优化工艺为:接种量10%、装液量40%、初始Fe2+质量浓度1000mg/L、培养时间24h、初始pH4.0、培养温度28℃、摇床转速200r/min,培养结束生物量为(14.68±0.37)g/L,细胞铁含量为(30.15±0.70)mg/g;以摇瓶实验为基础,采用50L培养罐中试放大,调整接种量15%、装液量60%,在对数生长初期2h内恒速流加Fe2+,培养18h,总铁含量最高达674.79mg/L,是摇瓶培养的1.52倍,富集率为67.48%,有机化程度为97.81%,转化率为66.00%。更多还原

【Abstract】 The biotransformation of iron in Chinese rice wine yeast(Saccharomyces cerevisiae) YS6.2.5 was investigated by tolerance and acclimation tests and culture conditions for iron biotransformation in a shake flask and a fermentor were optimized.The strain had strong iron tolerance and potential for iron biotransformation.The optimal culture conditions in a 500-mL shake flask were determined as follows: an inoculum size of 10%,a medium loading of 40%,and initial pH 4.0 for culture at 28 ℃ for 24 h at a shaking speed of 200 r/min.At the end of the culture period,the biomass and iron content of yeast cells were(14.68 ± 0.37) g/L and(30.15 ± 0.70) mg/g,respectively.The optimal culture conditions in a 50-L fermentor were determined as follows: an inoculum size of 15%,a medium loading of 60%,and addition of Fe2+at a constant flow rate during the early logarithmic growth phase.After 18 h culture under these conditions,the iron content of yeast cells was as high as 674.79 mg/L,which was 1.52-fold higher than shake flask culture,and the enrichment factor,the percentage of organic iron and conversaion rate were 67.48%,97.81% and 66.00%,respectivley.更多还原