Effect of overexpression of partial TDH1 and TDH2/3 gene sequences in a starter strain of industrial bioethanol fermentation on the Brettanomyces bruxellensis contaminant growth.

This article focuses on the development of genetically modified strains of the commercial yeast starter Ethanol-Red (ER) to overexpress antimicrobial peptides (AMPs) derived from glyceraldehyde 3-phosphate dehydrogenase (GAPDH), aiming to inhibit the growth of Brettanomyces bruxellensis, a common contaminant in bioethanol fermentations. By inserting partial sequences of the TDH1 and TDH2/3 genes encoding these AMPs into ER strains, the modified yeasts demonstrated significantly enhanced inhibition of B. bruxellensis during fermentations in synthetic must and carob syrup, with ethanol production maintained at industrially relevant levels. This genetic approach offers a potential alternative to chemical biocides, potentially improving the microbial control, economic viability, and environmental sustainability of bioethanol production processes.