Abstract

Without proper management, the wine industry produces a lot of byproducts and residues, which are bad for the environment. Vine shoots, wine lees, and surplus grape must have the potential to be utilized as renewable resources for the production of chemicals and energy. Saccharomyces cerevisiae is now recognized as an effective microbial cell factory for biorefineries thanks to efforts in metabolic engineering. The bioeconomy would clearly benefit if these biorefineries could effectively convert multiple feedstocks, but the current biorefineries designed for producing multiple products frequently rely on just one feedstock. Additionally, a biorefinery ought to be able to supplement the production of biofuel with the production of high-value products in order to maximize production economics and minimize the impact on the environment of fossil fuel consumption [1]. Through the biosynthesis of xylitol and ethanol, this study proposes an integrated strategy for the valorization of various wastes from winemaking processes. The xylose-rich hemicellulosic fraction of hydrothermally pretreated vine shoots was turned into xylitol with genetically modified S.cerevisiae strains, and the cellulosic fraction was used to make bioethanol. Additionally, sugar-rich grape must was
successfully utilized as a low-cost source for yeast propagation. In a Simultaneous Saccharification and Fermentation process configuration, the inoculum size and enzyme loading were adjusted to optimize xylitol production. Bioethanol was also produced from the glucan-rich cellulosic using a yeast strain with cellulases on the cell surface. High ethanol concentrations were achieved with the addition of wine lees or grape must, which are essential for the economic viability of distillation [2]. A synergistic alternative for reducing the amount of waste released into the environment while simultaneously converting a variety of winery wastes and by-products into biofuel and an added-value chemical is this integrated multi-feedstock valorization.