Effect of deletion and overexpression of tryptophan metabolism genes on growth and fermentation capacity at low temperature in wine yeast.
Low-temperature fermentations produce wines with greater aromatic complexity, but the success of these fermentations greatly depends on the adaptation of yeast cells to cold. Tryptophan has been previously reported to be a limiting amino acid during Saccharomyces cerevisiae growth at low temperature. The objective of this study was to determine the influence of the tryptophan metabolism on growth and fermentation performance during low-temperature wine fermentation. To this end, we constructed the deletion mutants of the TRP1 and TAT2 genes in a derivative haploid of a commercial wine strain, and the TAT2 gene was overexpressed in the prototroph and auxotroph (Δtrp1) backgrounds. Then we characterized growth and fermentation activity during wine fermentation at low and optimum temperatures. Our results partially support the role of this amino acid in cold yeast growth. Although deletion of TRP1 impaired amino acid uptake and the growth rate at low temperature in synthetic must, this growth impairment did not affect the fermentation rate. Deletion of TAT2 endorsed this strain with the highest nitrogen consumption capacity and the greatest fermentation activity at low temperature. Our results also evidenced reduced ammonium consumption in all the strains at low temperature.
Dept. de Biotecnología de los alimentos, Inst. de Agroquímica y Tecnología de los Alimentos (CSIC), Avda, Agustín Escardino, 7, E-46980-Paterna, Valencia, Spain; Dept. de Bioquímica i Biotecnologia, Biotecnologia Enològica, Facultat d'Enologia, Universitat Rovira i Virgili, Marcel·li Domingo s/n, 43007, Tarragona, Spain.
María
M
López-Malo
Estefani
E
García-Rios
Rosana
R
Chiva
José Manuel
JM
Guillamon
María
M
Martí-Raga
D019747:Aldose-Ketose Isomerases / Q000235:genetics* / Q000378:metabolism; D026905:Amino Acid Transport Systems / Q000235:genetics* / Q000378:metabolism; D064751:Ammonium Compounds / Q000378:metabolism; D005285:Fermentation; D015966:Gene Expression Regulation, Fungal; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D013696:Temperature; D014364:Tryptophan / Q000235:genetics* / Q000378:metabolism; D014920:Wine / Q000382:microbiology
D026905:Amino Acid Transport Systems; D064751:Ammonium Compounds; D029701:Saccharomyces cerevisiae Proteins; C429825:TAT2 protein, S cerevisiae; D014364:Tryptophan; D019747:Aldose-Ketose Isomerases; C490353:TRP1 protein, S cerevisiae
TAT2; cold; mutant; nitrogen; overexpressing strains; wine; yeast