发酵液中3-羟基丁酮的乙醇-磷酸氢二钾双水相体系分离

Separation of Acetoin from Fermentation Broth Using Ethanol-dipotassium Hydrogen Phosphate Aqueous Two-phase System

摘要:

微生物发酵法生产3-羟基丁酮亟待解决的一个问题是它的下游分离工艺的确定，双水相萃取技术作为一种高效而温和的分离技术，已经在有机物质的分离提取中得到了广泛的应用，本文开展了该双水相萃取技术分离发酵液中3-羟基丁酮的研究，考察了双水相体系的种类以及组成比例对3-羟基丁酮萃取的影响，确定最佳的双水相体系为无水乙醇/磷酸氢二钾，当无水乙醇的质量浓度为26%（m/m），磷酸氢二钾的质量浓度为25%（m/m），此时的3-羟基丁酮分配系数为16.81，回收率高达98.2%，放大操作表明该双水相体系的稳定性较好，体系规模的改变不会影响到3-羟基丁酮的分配系数和回收率，适用于大规模工业化生产，并且通过减压蒸馏和结晶得到了3-羟基丁酮二聚体产品，进一步验证了该工艺在3-羟基丁酮分离中的应用潜力。

Abstract:

The downstream separation process during acetoin production by microbial fermentation has long required investigation. Aqueous two-phase system (ATPS) is a highly efficient and mild separation technology, used extensively in the separation of organic substances. The application of ATPS in the separation of acetoin from fermentation broths was investigated, the effects of the types and compositions of ATPS on the extraction of acetoin were explored, and the ethanol/dipotassium hydrogen phosphate system was determined as the optimal ATPS. The highest partition coefficient (16.81) and recovery (98.2%) of acetoin were obtained, when the mass concentrations of dipotassium hydrogen phosphate and ethanol were 25% (m/m) and 26% (m/m), respectively. A pilot experiment indicated that the ATPS showed good stability, and changes in the scale of the system did not affect the partition coefficient and recovery for acetoin. This shows that the ethanol/dipotassium hydrogen phosphate ATPS can be applied to large-scale industrial production. Finally, acetoin dimers were produced using vacuum distillation and crystallization, further demonstrating the potential application of this ATPS process for acetoin separation from fermentation broth.