Codon-optimized glucoamylase sGAI of Aspergillus awamori improves starch utilization in an industrial yeast
Date
2012
Authors
Favaro L.
Jooste T.
Basaglia M.
Rose S.H.
Saayman M.
Gorgens J.F.
Casella S.
Van Zyl W.H.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The development of a yeast that converts raw starch to ethanol in one step (called consolidated bioprocessing) could yield large cost reductions in the bioethanol industry. The aim of this study was to develop an efficient amylolytic Saccharomyces cerevisiae strain suitable for industrial bioethanol production. A native and codon-optimized variant of the Aspergillus awamori glucoamylase gene were expressed in the S. cerevisiae Y294 laboratory strain. Codon optimization resulted to be effective and the synthetic sequence sGAI was then d-integrated into a S. cerevisiae strain with promising industrial fermentative traits. The mitotically stable recombinant strains showed high enzymatic capabilities both on soluble and raw starch (2425 and 1140 nkat/g dry cell weight, respectively). On raw corn starch, the engineered yeasts exhibited improved fermentative performance with an ethanol yield of 0.42 (g/g), corresponding to 75 % of the theoretical maximum yield. © Springer-Verlag 2012.
Description
Article
Keywords
Codon optimization, D-integration, Ethanol production, Industrial yeast, Raw starch
Citation
Applied Microbiology and Biotechnology
95
4
957
968
95
4
957
968