3-羟基丙酸高产菌株的筛选及诱变选育

【目的】3-羟基丙酸是一种重要的化学平台化合物,期望得到一株能够高产3-羟基丙酸的菌株。【方法】从土壤及粪便筛选并对得到的菌株进行鉴定和复合诱变。【结果】得到了一株能够利用丙酸发酵生产3-羟基丙酸的酵母Y-11,经生理生化鉴定及18S rDNA序列分析确定其为Candida sp.(假丝酵母)。以Y-11为出发菌株,经紫外-亚硝基胍-60Coγ复合诱变得到了突变性状稳定且可遗传的高产菌株5-13B,其3-羟基丙酸的产量为11.78 g/L,是出发菌株的2.46倍。【结论】对出发菌株和突变株的发酵特性进行了比较,结果表明突变株的3-羟基丙酸产量、对底物丙酸的转化率、产物3-羟基丙酸的积累性能及丙酸的耐受性均优于出发菌株。

Isolation, identification and mutation breeding of 3-hydroxypropionic acid high production strain

Objective] 3-HP is an important bio-based platform compound.We wanted to iso1356 late a strain which can produce 3-HP.Methods] We isolated samples of soil(17) and feces(10) and did physiological-biochemical identification and 18S rDNA sequence analysis with Y-11.Then we used UV-NTG-60Coγ to generate mutations.Results] A yeast Y-11 which can use propionic acid to produce 3-HP was screened by us.It was identified as Candida sp..We used UV-NTG-60Coγ to generate mutations in Y-11 and got a genetic stability mutant,designated as 5-13B.The mutant 5-13B showed the productivity of 3-hydroxypropionic acid is 11.78 g/L,2.46 times as that of the primitive strain(Y-11).Conclusion] The fermentation characters of primitive strain and mutant strain were compared.The results showed that the consumption rate of propionic acid,accumulation of 3-hydroxypropionic acid and tolerance of propionic acid of mutant strain are better than primitive strain.