COMPOSITIONS AND METHODS FOR REDUCTION OF LEVEL OF HS IN FERMENTED BEVERAGES Russian patent published in 2013 - IPC C12N1/19 C12N15/63 C12N15/09 C12N15/53 

FIELD: biotechnology.

SUBSTANCE: versions of modified yeast cells are presented. Each of the versions produces hydrogen sulfide at a reduced level and includes exogenous polynucleotide encoding a polypeptide MET10 which catalyses the transformation reaction of sulfite to sulfide at a reduced level, where the amino acid at the position 662 of the polypeptide MET10 is Ala, Asp, Glu, Phe, Gly, His, He, Lys, Leu, Asn, Gin, Arg, Val, Trp or Tyr (SEQ ID NO: 5). The expression vector is described comprising the said exogenous polynucleotide. The culture of the said cells is described. A method of preparing the said yeast cell is proposed, including the replacement of endogenous polynucleotide encoding a sulfide-active polypeptide MET10 to polynucleotide encoding MET10 with the said replacement at the position 662 SEQ ID NO: 5, and the parent yeast cell produces hydrogen sulfide. The method of reduction of H₂S level in fermentation medium is described, including the contact of the fermentation medium with the mentioned above yeast cell. The fermentation medium and the fermentation product are proposed containing the said cell or the cell culture.

EFFECT: invention enables to reduce the level of H₂S in the fermentation medium in production of fermented beverages.

56 cl, 8 dwg, 11 tbl, 4 ex