NOVELTY - Recombinant yeast microorganism comprising a metabolic pathway for the production of a pyruvate-derived metabolite, is new, where the metabolic pathway comprises at least one exogenous gene and/or at least one over expressed endogenous gene encoding an enzyme that catalyzes a pathway step in the production of the pyruvate-derived metabolite.    USE - The recombinant yeast microorganism is useful for producing a pyruvate-derived metabolite, which is isobutanol, 2-butanol, 1-butanol, 2-butanone, 2,3-butanediol, acetoin, diacetyl, valine, leucine, pantothenic acid, isobutylene, 3-methyl-1-butanol, 4-methyl-1-pentanol, coenzyme A, lactic acid or malic acid (all claimed).    ADVANTAGE - The recombinant yeast microorganism prepares the pyruvate-derived metabolite with improved growth properties in a cost effective manner.    DETAILED DESCRIPTION - Recombinant yeast microorganism comprising a metabolic pathway for the production of a pyruvate-derived metabolite, is new, where: the metabolic pathway comprises at least one exogenous gene and/or at least one over expressed endogenous gene encoding an enzyme that catalyzes a pathway step in the production of the pyruvate-derived metabolite; the recombinant yeast microorganism is engineered to comprise reduced pyruvate decarboxylase (PDC) activity; and the recombinant yeast microorganism is engineered to comprise at least one first modification which results in improved growth in the absence of 2C-supplementation as compared to the corresponding recombinant yeast microorganism without the first modification, and/or comprise at least one second modification which results in improved tolerance to high glucose concentrations as compared to the corresponding recombinant yeast microorganism without the second modification. INDEPENDENT CLAIMS are included for:    (1) producing the pyruvate-derived metabolite comprising providing the recombinant yeast microorganism, and cultivating the recombinant yeast microorganism in a culture medium containing a feedstock providing a carbon source, until the pyruvate-derived metabolite is produced; and    (2) an isolated nucleic acid molecule encoding the amino acid sequence of SEQ ID NO: 23 or SEQ ID NO: 28, where sequences not defined here may be found at ftp://ftp.wipo.int/pub/published-pct-sequences/publication.