Development of a Saccharomyces cerevisiae strain for the bioconsolidated processing of Agave sisalana

Abstract

The production of feedstocks for the bioethanol industry faces two major challenges: i) the competition with food production, for land and water use; and ii) the decay in productivity of cultivations in the context of climate change. Thus, the search for biomasses that overcome such obstacles becomes essential to the advance of bioeconomy in a context of changes in the energetic paradigm. In this sense, agave (Agave sisalana) stands out as a promising option for biofuel production. Largely cultivated in brazilian northeastern hinterland, arid region and inadequate for other cultures planting, this plant is employed today almost exclusively for sisal fiber production in Brazil. However, agave is rich in inulin type fructans, which can be hydrolyzed to fructose and glucose monomers (fermentable sugars) by inulinase enzymes. The agave fermentation is currently commercially restricted to alcoholic beverages production, despite its biotechnological potential for the production of fuels. Hence, this project aims to enable the production of ethanol from a biomass that is underexploited and highly adaptable to extreme climate conditions. In order to do so, a modified strain of Saccharomyces cerevisiae for the consolidated bioprocessing of A. sisalana will be constructed, through the expression of a new exoinulinase for the simultaneous hydrolysis and fermentation of inulins. In parallel, natural S. cerevisiae strains from the Brazilian sugar and alcohol industry will be prospected for the fermentation of the thermic hydrolyzate of the juice of agave leaves.