Harnessing the nutritional potential of concentrated whey for enhanced galactose flux in fermentative yeast. (April 2021)

• Record Type: Journal Article
• Authors: Beniwal, Arun; Saini, Priyanka; De, Sachinandan; Vij, Shilpa
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 141(2021)
• Publication Date: 2021-04
• Subjects: CRISPR -- Whey -- Galactose -- Saccharomyces cerevisiae -- Ethanol; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2020.110840
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: The primary effluent of Indian dairy industries, cheese whey, and its main component lactose is considered an environmental pollutant due to its high chemical and biological oxygen demand. The model fermentative yeast, Saccharomyces cerevisiae, does not possess the necessary enzyme to utilize lactose in whey. In the present study, metabolic engineering of wild type S. cerevisiae strain with CRISPR Cas9 system was used to construct a cell factory that can flux higher galactose from the concentrated whey medium. The improved utilization of galactose confers fermentative metabolism with improved ethanol production rate. The strain provided a high titer of the ethanol (0.32 ± 0.007 g/g) with improved galactose flux from concentrated whey at the expense of the biomass, glycerol, and acetic acid. Our present study provides evidence that galactose to ethanol fermentation is a feasible alternative for industrial waste stream treatment in developing countries. Highlights: Wild type S.cerevisiae strain was genetically engineered by CRISPR Cas9 tool. The engineered strain had an enhanced utilization rate of galactose from cheese whey. The engineered strain had improved stability and productivity of ethanol. Gal80p was not responsible for catabolite repression in cheese whey medium.