Thermotolerant Bacillus licheniformis TY7 produces optically active L-lactic acid from kitchen refuse under open condition

A thermotolerant L-lactic-acid-producing bacterium was isolated and identified as Bacillus licheniformis TY7. TY7 shows optimum growth at pH 6.5 at 30 degrees C and normal growth up to 65 degrees C. Using nonsterile kitchen refuse at 50 degrees C, the strain produced 40 g/l L-lactic acid with 97% optical activity and 2.5 g/l center dot h productivity.