Genome structure of a Saccharomyces cerevisiae strain widely used in bioethanol production.
Bioethanol is a biofuel produced mainly from the fermentation of carbohydrates derived from agricultural feedstocks by the yeast Saccharomyces cerevisiae. One of the most widely adopted strains is PE-2, a heterothallic diploid naturally adapted to the sugar cane fermentation process used in Brazil. Here we report the molecular genetic analysis of a PE-2 derived diploid (JAY270), and the complete genome sequence of a haploid derivative (JAY291). The JAY270 genome is highly heterozygous (approximately 2 SNPs/kb) and has several structural polymorphisms between homologous chromosomes. These chromosomal rearrangements are confined to the peripheral regions of the chromosomes, with breakpoints within repetitive DNA sequences. Despite its complex karyotype, this diploid, when sporulated, had a high frequency of viable spores. Hybrid diploids formed by outcrossing with the laboratory strain S288c also displayed good spore viability. Thus, the rearrangements that exist near the ends of chromosomes do not impair meiosis, as they do not span regions that contain essential genes. This observation is consistent with a model in which the peripheral regions of chromosomes represent plastic domains of the genome that are free to recombine ectopically and experiment with alternative structures. We also explored features of the JAY270 and JAY291 genomes that help explain their high adaptation to industrial environments, exhibiting desirable phenotypes such as high ethanol and cell mass production and high temperature and oxidative stress tolerance. The genomic manipulation of such strains could enable the creation of a new generation of industrial organisms, ideally suited for use as delivery vehicles for future bioenergy technologies.
Argueso
Juan Lucas
JL
Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA. lucas.argueso@duke.edu
Carazzolle
Marcelo F
MF
Mieczkowski
Piotr A
PA
Duarte
Fabiana M
FM
Netto
Osmar V C
OV
Missawa
Silvia K
SK
Galzerani
Felipe
F
Costa
Gustavo G L
GG
Vidal
Ramon O
RO
Noronha
Melline F
MF
Dominska
Margaret
M
Andrietta
Maria G S
MG
Andrietta
Sílvio R
SR
Cunha
Anderson F
AF
Gomes
Luiz H
LH
Tavares
Flavio C A
FC
Alcarde
André R
AR
Dietrich
Fred S
FS
McCusker
John H
JH
Petes
Thomas D
TD
Pereira
Gonçalo A G
GA
D056804:Biofuels; D001938:Brazil; D015825:Chromosomes, Fungal; D004271:DNA, Fungal / Q000032:analysis; D004171:Diploidy; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D016681:Genome, Fungal / Q000235:genetics*; D006238:Haploidy; D007218:Industrial Microbiology; D008969:Molecular Sequence Data; D010641:Phenotype; D011110:Polymorphism, Genetic; D012441:Saccharomyces cerevisiae / Q000145:classification* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000235:genetics / Q000502:physiology
D056804:Biofuels; D004271:DNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol