Industrial fuel ethanol yeasts contain adaptive copy number changes in genes involved in vitamin B1 and B6 biosynthesis
- 1Department of Genetics, Stanford University, Stanford, California 94305-5120, USA;
- 2Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil
Abstract
Fuel ethanol is now a global energy commodity that is competitive with gasoline. Using microarray-based comparative genome hybridization (aCGH), we have determined gene copy number variations (CNVs) common to five industrially important fuel ethanol Saccharomyces cerevisiae strains responsible for the production of billions of gallons of fuel ethanol per year from sugarcane. These strains have significant amplifications of the telomeric SNO and SNZ genes, which are involved in the biosynthesis of vitamins B6 (pyridoxine) and B1 (thiamin). We show that increased copy number of these genes confers the ability to grow more efficiently under the repressing effects of thiamin, especially in medium lacking pyridoxine and with high sugar concentrations. These genetic changes have likely been adaptive and selected for in the industrial environment, and may be required for the efficient utilization of biomass-derived sugars from other renewable feedstocks.
Footnotes
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↵3 Corresponding authors.
E-mail sherlock{at}genome.stanford.edu; fax (650) 724-3701.
E-mail bstambuk{at}mbox1.ufsc.br; fax +5548-3721-9672.
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[Supplemental material is available online at http://www.genome.org. The microarray data from this study have been submitted to Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/) under accession no. GSE13875.]
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Article published online before print. Article and publication date are at http://www.genome.org/cgi/doi/10.1101/gr.094276.109.
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- Received March 24, 2009.
- Accepted September 24, 2009.
- Copyright © 2009 by Cold Spring Harbor Laboratory Press
