Polyhexamethyl biguanide can eliminate contaminant yeasts from fuel-ethanol fermentation process

• Published in: Journal of industrial microbiology & biotechnology Vol. 35; no. 9; pp. 967 - 973
• Main Authors: Elsztein, Carolina, de Menezes, João Assis Scavuzzi, de Morais, Marcos Antonio Jr
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01-09-2008; Springer-Verlag; Springer; Oxford University Press
• Subjects: alcoholic fermentation; biguanides; Biguanides - chemistry; Biguanides - pharmacology; Biochemistry; Biofuel production; biofuels; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Contaminants; Contamination; Culture Media; decontamination; Dekkera bruxellensis; Distilleries; Drug Resistance, Fungal - drug effects; Energy; Ethanol; Ethanol - metabolism; Ethanol - pharmacology; ethanol fuels; Experiments; Fermentation; Fundamental and applied biological sciences. Psychology; Fungicides; Fungicides, Industrial - pharmacology; Genetic Engineering; Glucose - pharmacology; Gram-positive bacteria; Industrial applications and implications. Economical aspects; Industrial Microbiology; Industrial pollution; Inorganic Chemistry; Life Sciences; Methods. Procedures. Technologies; microbial contamination; Microbial engineering. Fermentation and microbial culture technology; Microbiology; Microorganisms; molasses; Original Paper; Pesticides; Pollution control; Population; Productivity; renewable energy sources; Saccharomyces; Saccharomyces cerevisiae; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharum officinarum; Studies; Sugarcane; Survival Analysis; Yeast; Yeasts; Yeasts - drug effects; Yeasts - growth & development; Yeasts - metabolism; PHMB; Ethanol fermentation; Fungicide; Contaminant yeast; Yeast; Ethanol; Pesticides; Biofuel; Ethanol fermentation . Fungicide; Fermentation; Operating process; Contaminant; Contaminant yeast .Dekkera bruxellensis
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1007/s10295-008-0371-4

Industrial ethanol fermentation is a non-sterile process and contaminant microorganisms can lead to a decrease in industrial productivity and significant economic loss. Nowadays, some distilleries in Northeastern Brazil deal with bacterial contamination by decreasing must pH and adding bactericides. Alternatively, contamination can be challenged by adding a pure batch of Saccharomyces cerevisiae--a time-consuming and costly process. A better strategy might involve the development of a fungicide that kills contaminant yeasts while preserving S. cerevisiae cells. Here, we show that polyhexamethyl biguanide (PHMB) inhibits and kills the most important contaminant yeasts detected in the distilleries of Northeastern Brazil without affecting the cell viability and fermentation capacity of S. cerevisiae. Moreover, some physiological data suggest that PHMB acts through interaction with the yeast membrane. These results support the development of a new strategy for controlling contaminant yeast population whilst keeping industrial yields high.