Efficient production of l-lactic acid by newly isolated thermophilic Bacillus coagulans WCP10-4 with high glucose tolerance

• Published in: Applied microbiology and biotechnology 2013-05, Vol.97 (10), p.4309-4314
• Main Authors: Zhou, Xingding, Ye, Lidan, Wu, Jin Chuan
• Format: Article
• Language: English
• Subjects: Acid production; Analysis; Bacillus - metabolism; Bacillus coagulans; Bacteria; Base Sequence; Biomedical and Life Sciences; Biosynthesis; Biotechnological Products and Process Engineering; Biotechnology; Chemical synthesis; Dextrose; DNA Primers; Enzymes; Fermentation; Glucose; Glucose - metabolism; Hydrogen-Ion Concentration; Lactic Acid - biosynthesis; Life Sciences; Microbial Genetics and Genomics; Microbiology; Organic acids; Productivity; Starch; Starch - metabolism; Studies; Yeast
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-013-4710-7

A thermophilic Bacillus coagulans WCP10-4 with tolerance to high concentration of glucose was isolated from soil and used to produce optically pure l -lactic acid from glucose and starch. In batch fermentation at pH 6.0, 240 g/L of glucose was completely consumed giving 210 g/L of l -lactic acid with a yield of 95 % and a productivity of 3.5 g/L/h. In simultaneous saccharification and fermentation at 50 °C without sterilizing the medium, 200 g/L of corn starch was completely consumed producing 202.0 g/L of l -lactic acid. To the best of our knowledge, this strain shows the highest osmotic tolerance to glucose among the strains ever reported for lactic acid production. This is the first report of simultaneous saccharification and fermentation of starch for lactic acid production under a non-sterilized condition.