Efficient Production of Optically Pure d-Lactic Acid from Raw Corn Starch by Using a Genetically Modified l-Lactate Dehydrogenase Gene-Deficient and α-Amylase-Secreting Lactobacillus plantarum Strain

摘要: In order to achieve direct and efficient fermentation of optically pure d-lactic acid from raw corn starch, we constructed l-lactate dehydrogenase gene (ldhL1)-deficient Lactobacillus plantarum introduced a plasmid encoding Streptococcus bovis 148 α-amylase (AmyA). The resulting strain produced only glucose successfully expressed amyA. With the aid secreting AmyA, starch was accomplished. After 48 h fermentation, 73.2 g/liter lactic with high yield (0.85 g per consumed sugar) an optical purity 99.6%. Moreover, replacing ldhL1 amyA-secreting expression cassette constructed. Using this strain, accomplished in absence selective pressure by antibiotics. This is first report starch.