钙盐沉淀法从酮酸发酵液中提取α-酮戊二酸

Extraction of α-Ketoglutaric Acid from Fermentation Broth by Calcium Precipitation Method

摘要:

α-酮戊二酸作为一种重要的有机酸，在食品、化工、医药等领域具有广泛的用途。目前，发酵法是生产α-酮戊二酸最具优势的方法。但在解脂亚洛酵母发酵生产α-酮戊二酸的过程中，丙酮酸作为副产物总是大量积累。这2种酮酸物化性质相似，为下游分离提取过程造成了很大的困难。研究对比3种不同钙盐对酮酸分离的影响，建立了一种有效分离发酵液中α-酮戊二酸的钙盐沉淀方法。采用CaCO ₃为α-酮戊二酸的最佳沉淀剂，α-酮戊二酸的回收率和纯度分别为82.5%和98.89%。同时，结果表明在偏中性和高温作用下，丙酮酸的稳定性受到影响，丙酮酸分离不适用于钙盐沉淀法。该研究可为酮酸的分离提取过程提供重要的理论参考。

Abstract:

α-Ketoglutaric acid is widely used in food，chemical and pharmaceutical industries as an important organic acid. Fermentative production of α-ketoglutaric acid by Yarrowia lipolytica is currently a competitive method. The accumulation of pyruvic acid is unavoidable during the production of α-ketoglutaric acid by Y. lipolytica. The two keto acids have similar physical and chemical properties，which brings big challenge for the downstream separation process. In this study，effects of three different calcium salts on the separation of keto acids in the fermentation broth were compared. An effective precipitation method was established for the separation of α-ketoglutaric acid from fermentation broth. CaCO ₃ was the optimum precipitant of α-ketoglutaric acid. The recovery and purity rate of α-ketoglutaric acid were 82.5% and 98.89%，respectively. Meanwhile，the precipitation method could not be used for the separation of pyruvic acid，because pyruvic acid was unstable under the partial neutrality and high temperature. This study can thus provide an important theoretical reference for the separation and extraction of keto-acid.