Strain improvement of Saccharomyces cerevisiae by diethyl sulfate (DES) mutagenesis for efficient ethanol bioproduction

The present study focuses on the strain improvement of Saccharomyces cerevisiae NCIM1267 through chemical mutagenesis using diethyl sulfate (DES) to enhance ethanol bioproduction efficiency. Wild-type cultures were subjected to varying concentrations and exposure durations of DES to induce random genetic mutations. Mutagen-treated strains were screened for ethanol tolerance, fermentation efficiency, and sugar utilization rates under controlled fermentation conditions. Selected high-yielding mutants demonstrated improved ethanol productivity, reduced fermentation time, and enhanced tolerance to higher ethanol concentrations compared to the parental strain. Physiological and biochemical evaluations revealed increased fermentative activity, likely attributed to altered metabolic fluxes favoring ethanol synthesis. The optimized mutant strains achieved a significant increase in ethanol yield, indicating the potential of DES mutagenesis as a practical approach for industrial strain development. These findings contribute to the development of robust yeast. strains suitable for large-scale, cost-effective ethanol production from natural feedstocks. In the present study the impact of diethyl sulfate on strain improvement of Saccharomyces cerevisiae NCIM1267 has been explored. It has been found that DES mutagen acts as a modulator and stimulator and enhances the yield of ethanol to an extent of 14.776% higher in comparison to control when 25% of molasses solution is allowed to ferment at pH 5.2, temperature 300C and incubation period of 50 hrs.