Abstract
Engineering of Saccharomyces cerevisiae to produce advanced biofuels such as isobutanol has received much attention because this yeast has a natural capacity to produce higher alcohols. In this study, construction of isobutanol production systemswas attempted by overexpression of effective 2-keto acid decarboxylase (KDC) and combinatorial overexpression of valine biosynthetic enzymes in S. cerevisiae D452-2. Among the six putative KDC enzymes from various microorganisms, 2-ketoisovalerate decarboxylase (Kivd) from L. lactis subsp. lactis KACC 13877 was identified as the most suitableKDCfor isobutanol production in the yeast. Isobutanol production by the engineered S. cerevisiae was assessed in micro-aerobic batch fermentations using glucose as a sole carbon source. 93 mg/L isobutanol was produced in the Kivd overexpressing strain, which corresponds to a fourfold improvement as compared with the control strain. Isobutanol production was further enhanced to 151 mg/L by additional overexpression of acetolactate synthase (Ilv2p), acetohydroxyacid reductoisomerase (Ilv5p), and dihydroxyacid dehydratase (Ilv3p) in the cytosol.
Original language | English (US) |
---|---|
Pages (from-to) | 1467-1475 |
Number of pages | 9 |
Journal | Bioprocess and Biosystems Engineering |
Volume | 35 |
Issue number | 9 |
DOIs | |
State | Published - Nov 2012 |
Bibliographical note
Funding Information:Acknowledgments This research was supported by the Advanced Biomass R&D Center (ABC) of Korea Grant funded by the Ministry of Education, Science and Technology (2010-0029799) and the Marine Biotechnology Program funded by the Ministry of Land, Transport and Maritime Affairs of Korean Government.
Keywords
- 2-Ketoisovalerate decarboxylase
- Engineered Saccharomyces cerevisiae
- Isobutanol
- Valine biosynthetic enzymes