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In this study, sorghum meal underwent 2–10 kGy electron beam irradiation (EBI) to investigate alterations in its elemental composition, relevant physicochemical characteristics, and enzymatic hydrolysis fermentation properties. The results indicated a decrease in amylose content and an increase in reducing sugar content in sorghum meal after EBI, along with severe damage to the internal structure of starch granules, leading to increased solubility in water. Furthermore, irradiation enhanced the shear resistance and gelatinization stability of sorghum meal paste. Most importantly, EBI-induced degradation of sorghum starch molecules enhanced their susceptibility to interact with α-amylase, significantly improving the enzymatic hydrolysis and alcohol fermentation efficiency of sorghum meal. At an irradiation dose of 8 kGy, raw and cooked sorghum meal exhibited a 43.40% and 33.33% increase in ethanol concentration and a 43.44% and 30.29% increase in ethanol yield, respectively. This finding indicated that irradiation is an effective pretreatment method for starch-based ethanol fermentation. [Display omitted] • Using EBI as a pretreatment for sorghum meal ethanol fermentation. • Sorghum starch molecules degraded after EBI treatment. • EBI notably enhanced sorghum meal's enzymatic saccharification efficiency. • The ethanol concentration and yield peaked at an EBI dose of 8 kGy. • EBI coupled with high-temperature cooking notably improved fermentation efficiency. [ABSTRACT FROM AUTHOR]

Sugarcane molasses is one of the main raw materials for bioethanol production, and Saccharomyces cerevisiae is the major biofuel-producing organism. In this study, a batch fermentation model has been used to examine ethanol titers of deletion mutants for all yeast nonessential genes in this yeast genome. A total of 42 genes are identified to be involved in ethanol production during fermentation of sugarcane molasses. Deletion mutants of seventeen genes show increased ethanol titers, while deletion mutants for twenty-five genes exhibit reduced ethanol titers. Two MAP kinases Hog1 and Kss1 controlling the high osmolarity and glycerol (HOG) signaling and the filamentous growth, respectively, are negatively involved in the regulation of ethanol production. In addition, twelve genes involved in amino acid metabolism are crucial for ethanol production during fermentation. Our findings provide novel targets and strategies for genetically engineering industrial yeast strains to improve ethanol titer during fermentation of sugarcane molasses. • Screening 4797 gene mutants for ethanol fermentation titers of sugarcane molasses. • Forty-two genes involved in ethanol production in sugarcane molasses fermentation. • Seventeen mutants show increased, but 25 mutants exhibit reduced, ethanol yields. • Two MAP kinases Hog1 and Kss1 negatively regulate ethanol production. • Amino acid metabolism are crucial for ethanol production during fermentation. [ABSTRACT FROM AUTHOR]