G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Prospect Nauki 5, Pushchino, Moscow region, 142290, Russia,
Appl Microbiol Biotechnol. 2013 Oct;97(19):8711-8. doi: 10.1007/s00253-013-5170-9. Epub 2013 Aug 16.
The replacement of chemical synthesis by environmentally friendly energy-efficient technologies for production of valuable metabolites is a principal strategy of developing biotechnological industry all over the world. In the present study, we develop a method for α-ketoglutaric acid (KGA) production from rapeseed oil with the use of Yarrowia lipolytica yeast. Sixty strains of Y. lipolytica yeasts were tested for their ability to produce KGA, and the strain Y. lipolytica 212 (Y. lipolytica VKM Y-2412) was selected as a promising KGA producer. Using a three-stage pH controlling, in which pH was 4.5 in the growth phase, then since 72 to 144 h, pH was maintained at 3.5 and in the later phase of acid production, the titration by KOH was switch off, selected strain produced 106.5 g l(-1) of KGA with mass yield of 0.95 g g(-1). KGA in the form of monopotassium salt was isolated from the culture broth and purified. The isolation procedure involved separation of biomass, extraction of residual triglycerides, filtrate bleaching, and acidification with mineral acid (to pH 2.8-3.4), concentration, precipitation of mineral salts, and crystallization of the product. The purity of KGA isolated from the culture filtrate reached 99.1 %.
用环保、节能的技术代替化学合成来生产有价值的代谢产物，是全世界发展生物技术产业的主要策略。本研究利用产朊假丝酵母开发了从菜籽油生产α-酮戊二酸（KGA）的方法。测试了 60 株产朊假丝酵母生产 KGA 的能力，选择产朊假丝酵母 212（产朊假丝酵母 VKM Y-2412）作为有前途的 KGA 生产菌。采用三阶段 pH 控制，在生长阶段 pH 为 4.5，72 至 144 小时后，pH 保持在 3.5，在产酸后期，停止用 KOH 滴定，选择的菌株生产 106.5 g/L 的 KGA，产率为 0.95 g/g。从发酵液中分离出 KGA 的单钾盐形式并进行了纯化。该分离过程包括生物质分离、残留甘油三酯的提取、滤液脱色、用矿物酸酸化（至 pH 2.8-3.4）、浓缩、无机盐沉淀和产物结晶。从发酵滤液中分离出的 KGA 的纯度达到 99.1%。
