Clinical Microbiology: Open Access

Comparative metabolomics and proteomics between Saccharomyces cerevisiae hybrids after adaptive evolution in the lignocellulosic substrate for bioethanol production

7^th Annual Summit on Microbiology: Education, R&D and Market

September 28-29, 2018 | San Antonio, USA

Thalita Peixoto Basso

University of Sao Paulo, Brazil

Posters & Accepted Abstracts: Clin Microbiol

Abstract:

In the search for alternative sources to fossil fuels, biofuels, such as bioethanol, are shown highly efficient. However, due to ethical issues regarding the use of foods such as sugar and corn in ethanol production, research has been carried out in search of by-products, such as lignocellulosic residues, which can be used in the production of bioethanol. Sugarcane bagasse is a promising by-product that can be used for this purpose, to be available in the plant, does not require transportation expenses, relatively be abundant and cheap. Nevertheless, lignocellulosic hydrolyzate from bagasse is constituted of non-naturally metabolizable sugars by Saccharomyces cerevisiae (employed microorganism for ethanol production), and the presence of inhibitors against microorganisms responsible for fermentation, as hydroxymethylfurfural, furfural and acetic acid formed during acid pretreatment of bagasse. The challenge of this work was to circumvent these difficulties through the use of S. cerevisiae hybrids tolerant to inhibitors found in the substrate for second-generation ethanol (2GE) production in Brazil. Such hybrids had been obtained in previous work by massal and direct crossings of mutagenized S. cerevisiae followed by adaptive evolution. These hybrids were genetically engineered with the cassette X123 containing the three genes responsible for xylose metabolism (xylose reductase, xylitol dehydrogenase, and xylulokinase), and then were followed by adaptive evolution (in YPX and hydrolysate media) in search of an optimal strain for pentose and hexose simultaneous fermentation. Therefore, the objective was to obtain strains with the potential of industrial use in the production of 2GE from sugarcane bagasse. The evolved strain was compared with the original by evaluating their physiological and technological traits. The proteomic and metabolomic analysis was performed in order to better understand the metabolic basis of any improvement observed.

Biography :

E-mail: tpbasso@usp.br