The aim of this work was to apply the evolutionary engineering to construct a mutant Saccharomyces cerevisiae HJ7-14 resistant on 2-deoxy-d-glucose and with an enhanced ability of bioethanol production from galactose, a mono-sugar in red algae. In batch and repeated-batch fermentations, HJ7-14 metabolized 5-fold more galactose and produced ethanol 2.1-fold faster than the parental D452-2 strain. Transcriptional analysis of genes involved in the galactose metabolism revealed that moderate relief from the glucose-mediated repression of the transcription of the GAL genes might enable HJ7-14 to metabolize galactose rapidly. HJ7-14 produced 7.4 g/L ethanol from hydrolysates of the red alga Gelidium amansii within 12 h, which was 1.5-times faster than that observed with D452-2. We demonstrate conclusively that evolutionary engineering is a promising tool to manipulate the complex galactose metabolism in S. cerevisiae to produce bioethanol from red alga.
Bibliographical noteFunding Information:
This work was financially supported by The Advanced Biomass R&D Center (ABC) of Korea Grant ( 2011-0031359 ) and also by the National Research Foundation of Korea ( NRF ) Grant ( 2013R1A2A2A01004806 and 2013M1A2A2072603 ) funded by the Korean Ministry of Science, ICT and Future Planning .
© 2015 Elsevier Ltd All rights reserved.
- Evolutionary engineering
- Red algae
- Saccharomyces cerevisiae
ASJC Scopus subject areas
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal