HIGHLY EFFICIENT PRODUCTION OF L (+)-LACTIC ACID USING MEDIUM WITH POTATO, CORN STEEP LIQUOR AND CALCIUM CARBONATE BY Lactobacillus rhamnosus ATCC 9595

Abstract The objective of this study was to optimize the composition of the fermentation medium through a Central Composite Rotational Design (CCRD) for the production of L (+)- latic acid (LA) using Lactobacillus rhamnosus ATCC 9595 and potato, corn steep liquor (CSL) and calcium carbonate as raw materials. A CCRD with three independent variables (potato flour (PF), CSL and CaCO3 concentrations) was performed for a total of 17 treatments. Kinetic studies were conducted, and samples were taken at time intervals of 0 to 72 h. Cell count, pH, reducing sugars and LA concentrations were determined. LA productivity and yield, sugar consumption and cell growth factor were calculated. The highest concentration of LA was 183.8 g/L, with 2.553 g/L.h productivity, 94.2% yield and 96.1 % sugar consumption.

摘要：本研究旨在采用中心复合旋转设计（Central Composite Rotational Design, CCRD）优化发酵培养基组成，以鼠李糖乳杆菌（Lactobacillus rhamnosus）ATCC 9595为发酵菌株，以马铃薯、玉米浆（corn steep liquor, CSL）及碳酸钙为原料，生产L(+)-乳酸（L (+)- lactic acid）。本研究设置包含3个自变量（马铃薯粉（potato flour, PF）浓度、玉米浆浓度及碳酸钙浓度）的中心复合旋转设计，共开展17组处理实验。随后进行动力学研究，于0至72 h内定时取样，测定细胞计数、pH值、还原糖浓度及乳酸浓度，并计算乳酸产率、得率、糖耗率及细胞生长因子。最终获得的最高乳酸浓度为183.8 g/L，产率达2.553 g/(L·h)，得率为94.2%，糖耗率达96.1%。