Seleção direcionada da Saccharomyces cerevisiae por alta pressão hidrostática para produção de etanol de segunda geração de casca de coco verde

Abstract

Coconut palm cultivation covers about 90 countries and Brazil stands out in the production of green coconut, with approximately 50 thousand hectares planted with high productivity and production all year round. This factor, together with the expansion of industrialization, which increases the shelf life of coconut water, lead to an increase in waste generation, especially green coconut husk, which is toxic if disposed of in the environment. To employ this residual biomass to produce biofuel can reduce environmental impacts and increase the income of the green coconut production chain, mainly benefiting small producers. Some strains of the yeast Saccharomyces cerevisiae are modified to increase the yield and economic viability of the process of converting lignocellulosic biomass into biofuel. High hydrostatic pressure (HHP) is a tool capable of simulating stresses that occur during fermentation. Thus, HHP can be used as a tool for targeted selection to obtain a strain with greater resistance to fermentative stresses and, consequently, a better fermentative performance. The main objective of this work is to use HHP as selective pressure in G2-104 strain to obtain a new strain with a higher fermentative capacity in the green coconut husk medium. G2-104 is a genetically modified yeast strain capable of fermenting 5-carbon sugars but not adapted to inhibitors present in green coconut husk. Thus, it was intended to contribute to the increase of the yield of the second generation ethanol production process. The results obtained with this work demonstrated the possibility of using this tool to obtain a strain that produces a higher ethanol yield in the fermentation of green coconut medium