3-羟基丙酸高产菌株的筛选及诱变选育

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

摘要:

【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。

Abstract:

[Objective] 3-HP is an important bio-based platform compound. We wanted to isolate 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.