We have investigated an experiment in order to get ethanol free lactic acid since brittle PLA is reported often in industry, therefore an adh-ve strain of Lactobacillus delbrueckii has been developed by mutating the cells by UV mutagenesis. The mutant cells were tested for its stability on Allyl alcohol and one of the best stable strains out of several selections was named as U12-1. U12-1 strain thus produced more than 8 % lactic acid without any alcohol. Subsequently nitrogen component was optimized by using L18 DOE applying Taguchi methodology. There was almost 20 % increase in lactic acid as compared to wild type. The new finding in this article is replacement of costly yeast extract with CSL, and Vit-B12 and also ethanol free lactic acid was produced confirmed by Gas chromatography. Confirmed results under optimal conditions fall in the 95 % confidence interval, indicating the experiments are reproducible and reliable.
