The Metabolic Control Breeding of L-Lactic Acid Fermentation and Optimization of Media and Cultivation Conditions

Abstract:

Based on the strain breeding theory and metabolic engineering theory, A high-yield mutant of Lactobacillus Thermophilus ATCC8317 was obtained through the compound inducements by the original Acetic acid-Sodium acetate plate and the productivity increased 210%.The best media components included saccharifying corn,malt powder 30g/L,peptone 5g/L.Based on the variety of specific cell growth rate and specific L-lactic acid production rate at different temperatures, the strategy of temperature control was obtained. The total product of L-lactic acid reached 135g/L besides the rate of glucose consumed and the average L-lactic acid productivity were up to 95% and 2.25g/(L·h) respectively.

Key words:L-lactic acid, Breeding, Optimization, Strategy of temperature control