strategy to prevent the occurrence of Lactobacillus strains using lactate-tolerant yeast Candida glabrata in bioethanol production

• Published in: Journal of industrial microbiology & biotechnology 2008-10, Vol.35 (10), p.1117-1122
• Main Authors: Watanabe, Itsuki, Nakamura, Toshihide, Shima, Jun
• Format: Article
• Language: English
• Subjects: alcoholic fermentation; Antibiotics; Bacteria; bacterial contamination; Biochemistry; Bioelectric Energy Sources - microbiology; Biofuels; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Candida glabrata; Candida glabrata - genetics; Candida glabrata - growth & development; Candida glabrata - isolation & purification; Candida glabrata - metabolism; Contamination; Ethanol; Ethanol - metabolism; ethanol production; Fermentation; Food contamination & poisoning; Fundamental and applied biological sciences. Psychology; Genetic Engineering; Glucose; Industrial Microbiology; Inorganic Chemistry; Laboratories; lactic acid; Lactic Acid - metabolism; Lactobacillus; Lactobacillus - growth & development; Lactobacillus - metabolism; Lactobacillus brevis; Lactobacillus fermentum; Life Sciences; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Microbiology; Original Paper; Research centers; Saccharomyces cerevisiae; Studies; Torulopsis glabrata; Yeast; Yeasts
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1007/s10295-008-0390-1

Contamination of Lactobacillus sp. in the fermentation broth of bioethanol production decreases ethanol production efficiency. Although the addition of lactate to the broth can effectively inhibit the growth of Lactobacillus sp., it also greatly reduces the fermentation ability of Saccharomyces cerevisiae. To overcome this conflict, lactate-tolerant yeast strains were screened. Candida glabrata strain NFRI 3164 was found to exhibit both higher levels of lactate tolerance and fermentation ability. Co-cultivation of C. glabrata was performed with Lactobacillus brevis and Lb. fermentum, which were reported as major contaminating bacteria during bioethanol production, in culture medium containing 2% lactate. Under these culture conditions, the growth of Lactobacillus strains was greatly inhibited, but the ethanol production of C. glabrata was not significantly affected. Our data show the possibility of designing an effective fuel ethanol production process that eliminates contamination by Lactobacillus strains through the combined use of lactate addition and C. glabrata.