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.