ARS | Publication request: Increased ethanol production with UV-C mutagenized Kluyveromyces marxianus capable of anaerobic growth at elevated temperature on pentose and hexose sugars using fermentation strategies with corn pericarp hydrolysates

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 30, 2012
Publication Date: August 30, 2012
Citation: Hughes, S.R., Kurtzman, C.P., Rich, J.O. 2012. Increased ethanol production with UV-C mutagenized Kluyveromyces marxianus capable of anaerobic growth at elevated temperature on pentose and hexose sugars using fermentation strategies with corn pericarp hydrolysates [abstract]. International Congress on Yeasts. IP175M.

Technical Abstract: Several novel Kluyveromyces marxianus strains were obtained by irradiation with UV-C (UV-C 234nm) to achieve an 80% mortality rate. The surviving cells were subsequently grown anaerobically for 5 months at 46C and resulted in two mutagenized strains that were able to grow anaerobically at elevated temperatures on all cellulosic sugars with higher ethanol production than wild type when grown on glucose or galacturonic acid. These more robust yeast strains derived from K. marxianus NRRL Y-1109 were produced specifically for anaerobic conversion of lignocellulosic sugar streams, including both pentose and hexose sugars, to fuel ethanol under industrial conditions at temperatures above 45C. The elevated temperature reduces possible contamination and is higher than that at which Saccharomyces cerevisiae can grow. This type of random mutagenesis offered the possibility of generating large numbers of mutations broadly over the whole genome of K. marxianus NRRL Y-1109. When all genes were subjected to irradiation and selected using automated plating strategies, changes were generated to produce genes that allowed improved utilization of sugars from lignocellulosic materials anaerobically in a shorter time frame at an elevated temperature with increased ethanol. Several biomass hydrolysates have been used for the production of cellulosic ethanol.