Biological alpha-ketoglutaric acid production by Yarrowia lipolytica using lignocellulosic hydrolysate: a potential feedstock for a bio-derived compound generation

Abstract

The global forestry sector, especially the pulp and paper industry segment, have increasingly sought the use of wood and waste components in its entirety for the production of new value-added products, such as organic acids. Woody biomass is comprised of at least four components: extractives, hemicellulose, lignin and cellulose. Considering this lignocellulosic biomass potential, a number of obstacles remain to be overcome, including non-optimal biomass degradation and limited tolerance of the candidate micro-organisms to inhibitory compounds produced after biomass pretreatment. As inhibitor detoxification procedures may raise process costs, an alternative option is to increase the robustness of the chosen micro-organism. In this context, the present internship project proposes to conduct an adaptive laboratory evolution (ALE) on the yeast Yarrowia lipolytica to increase its tolerance to the inhibitory-rich spent sulfite liquor (SSL) and to further evaluate the potential of ±-ketoglutaric acid (AKG) biosynthesis from spent sulfite liquor (SSL) by the adapted variant. Preliminary, we shall focus on screening the highest AKG producers among available Yarrowia species worldwide. After this step, the most promising strain will be submitted to the adaptation process consisting in repeated and successive batches with increasing percentage of lignocellulosic hydrolysate. Finally, yeast clones will be isolated from the adapted population and directed to physiological characterization for AKG production and tolerance to SSL. From this project regarding a bio-derived chemical compound production combined with batch fermentation operating procedures and microbiological approaches, an effective and applied method for sustainable innovation from wood and forestry waste lignocellulose-rich hydrolysate -including hexose and pentose fractions- is expected. The proposed internship in partnership with renowned Brazilian institutions (UNICAMP and CTBE), to be performed at the prestigious University of Lund, Sweden, will meet the policy and joint effort of the São Paulo Research Foundation (FAPESP), the Science, Technology and Innovation Ministry (MCTI) and the Education Ministry (MEC), to promote the consolidation, expansion and internationalization of science and technology, innovation and Brazilian competitiveness through the exchange and international mobility. (AU)