Study of genetics and alcoholgenic potential of wild yeasts isolated from several Brazilian regions aiming the production of bioethanol

Abstract

Ethanol has received lately more and more attention from researchers, companies and governments. This is due to the prospects of the depletion of non-renewable sources as well as the concerns about air pollution and green house effects. The extremely ambitious plans for ethanol consumption for the next years, mainly in developing countries, need a substantial increase in ethanol production and, accordingly, it stimulates the developing of new process production, using new raw materials to be converted into ethanol, including the lignocellulosic biomass. However, lignocellulosic residues, which are quite abundant, like sugar cane bagasse, are not converted to ethanol because they are complexes polymers not metabolized by yeasts. Therefore, if a yeast is intended to be used in the ethanol production directly from lignocellulosic sources, it is necessary to change genetically the production yeast, by removing undesirable genetic characteristics and add new genes in it (from other microorganism), so that it can degrade polymers and reducing them to single sugars and, by this way, to converted them to ethanol. Facing this, the main goal of this work is to study the lignocellulolitic properties of wild yeasts both collected and selected from different Brazilian regions, as well as to study its genetic characteristics aiming the bioethanol production. Yeasts are a poorly studied class of lignocellulolitc microorganisms concerning the natural production of cellulases, so from these yeasts, a strain with good potential for cellulase production will be selected. Afterwards, the genetic identification and characterization will be accomplished at the Laboratório de Genômica e Proteômica do Instituto de Biologia da UNICAMP. Once the specific genes of cellulases identified, they will be isolated, sequenced and expressed in Saccharomyces cerevisiae. At last, fermentations will be carried out with this genetically modified microorganism aiming the production of bioethanol from cellulose. (AU)