Whole-genome sequencing of the efficient industrial fuel-ethanol fermentative Saccharomyces cerevisiae strain CAT-1

Abstract

The Saccharomyces cerevisiae strains widely used for industrial fuel-ethanol production have been developed by selection, but their underlying beneficial genetic polymorphisms remain unknown. Here, we report the draft whole-genome sequence of the S. cerevisiae strain CAT-1, which is a dominant fuel-ethanol fermentative strain from the sugarcane industry in Brazil. Our results indicate that strain CAT-1 is a highly heterozygous diploid yeast strain, and the ~12-Mb genome of CAT-1, when compared with the reference S228c genome, contains ~36,000 homozygous and ~30,000 heterozygous single nucleotide polymorphisms, exhibiting an uneven distribution among chromosomes due to large genomic regions of loss of heterozygosity (LOH). In total, 58 % of the 6,652 predicted protein-coding genes of the CAT-1 genome constitute different alleles when compared with the genes present in the reference S288c genome. The CAT-1 genome contains a reduced number of transposable elements, as well as several gene deletions and duplications, especially at telomeric regions, some correlated with several of the physiological characteristics of this industrial fuel-ethanol strain. Phylogenetic analyses revealed that some genes were likely associated with traits important for bioethanol production. Identifying and characterizing the allelic variations controlling traits relevant to industrial fermentation should provide the basis for a forward genetics approach for developing better fermenting yeast strains.

Simultaneous cold hydrolysis and fermentation of fresh sweet potato

“…in its lyophilized form. This strain was isolated from industrial processes for ethanol production by Fermentec and Escola Superior de Agricultura Luiz de Queiroz [34]. The lyophilized yeast was stored at a temperature between 1 C and 5 C. For the fermentations, it was weighed and inoculated directly without pre-cultivation.…”

Revisiting Mortimer’s Genome Renewal Hypothesis: Heterozygosity, Homothallism, and the Potential for Adaptation in Yeast

“…For example, Magwene et al (2011), based on whole genome sequencing of 11 diploid isolates plus genotyping of nine loci in 18 additional strains, concluded that approximately 60% of strains they examined had modest (> 5,000 sites) to extensive (> 15,000 sites) genomic heterozygosity. Subsequent genome sequencing of additional environmental isolates has led to similar findings (Akao et al, 2011; Babrzadeh et al, 2012; Hyma and Fay, 2013). …”

Draft genome sequence of a natural isolated Saccharomyces cerevisiae from Colombia

“…Bioethanol is an ecological, clean, and renewable biofuel that merge as an option to dismiss the environmental impact of fossil fuels [1]. The predominant microorganisms responsible for the efficient production of ethanol are selected strains of the yeast Saccharomyces cerevisiae [1].…”

“…The predominant microorganisms responsible for the efficient production of ethanol are selected strains of the yeast Saccharomyces cerevisiae [1]. In this work we characterize the genome of a natural isolated strain of S. cerevisiae that was selected from a group of yeast because its potential to produce ethanol of first and second generation, comparable with other natural isolated and commercial strains (like Red Fermentis®) [2].…”