TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: (A) comprises 1-50 (preferably 1-10) mutated amino acids (preferably conservative amino acid substitutions) as compared to a wild-type cimA comprising SEQ ID NO: 89, where the mutation is at a residue, which is Ile-47 (preferably Ile-47-Val), His-126 (preferably His-126-Gln) and/or Thr-204 (preferably Thr-204-Ala). (A) is truncated following amino acid 373 of SEQ ID NO: 89, and comprises 373-491 amino acids (preferably the first 373 amino acids). In (A), the C-terminal 191 amino acids are missing compared to SEQ ID NO: 89. In (C2), the biosynthetic pathway for the production of an amino acid is modified for production of the alcohol, and where the 2-keto acid is 2-ketobutyrate. (C2) comprises: a deletion or knockout of an ethanol dehydrogenase gene (adhE), or its homolog or variant; a recombinant cimA, or its homolog or variant; or a 2-keto-acid decarboxylase. The 2-keto-acid decarboxylase is pyruvate decarboxylase (Pdc), Pdc1, Pdc5, Pdc6, Aro10, Thi3, alpha -ketoisovalerate decarboxylase (Kivd) or branched-chain keto-acid decarboxylase (KdcA), or their homolog or variant, or a polypeptide having at least 60% sequence identity to any one of the decarboxylases and having 2-keto-acid decarboxylase activity. The 2-keto-acid decarboxylase is encoded by a polynucleotide having at least 60% identity to a nucleic acid, which is pdc, pdc1, pdc5, pdc6, aro10, thi3, kivd (preferred), kdcA, or their homolog, variant or fragment. (C2) comprises at least one deletion or knockout in a gene encoding an enzyme that catalyzes: the conversion of acetyl-CoA to ethanol; the conversion of pyruvate to lactate; the conversion of fumarate to succinate; the conversion of acetyl-CoA and phosphate to CoA and acetyl phosphate respectively; the conversion of acetyl-CoA and formate to CoA and pyruvate respectively; the condensation of the acetyl group of acetyl-CoA with 3-methyl-2-oxobutanoate (2-oxoisovalerate); the isomerization between 2-isopropylmalate and 3-isopropylmalate; the conversion of alpha -keto acid to branched chain amino acids; the synthesis of phenylalanine, tyrosine, aspartic acid or leucine; the conversion of pyruvate to acetyl-Coenzyme A; the formation of branched chain amino acids; the formation of alpha -ketobutyrate from threonine; the first step in methionine biosynthesis; or the catabolism of threonine. (C2) comprises deletion of at least one gene, which is adhE, lactate dehydrogenase A (ldhA), fumarate reductase (frdB or C), fnr, phosphate acetyltransferase (pta), pyruvate formate lyase (pflB), branched-chain aminotransferases (ilvE, ilvB, ilvI, ilvA), tyrosine aminotransferase (tyrB), pyruvate oxidase (poxB), metA, threonine dehydrogenase (tdh), or their homologs or naturally occurring variants. (C2) comprises a genotype, which is a deletion or knockout of: delta -adhE, delta -ldhA, delta -pta, delta -poxB, delta -ilvB, delta -ilvI, delta -metA and/or delta -tdh, and comprises an expression or increased expression of kivd, threonine operon (ThrABC) comprising thrA, thrB and thrC, cimA and alcohol dehydrogenase 2 (adh2), where (C2) produces 1-propanol; delta -adhE, delta -ldhA, delta -frdB, delta -frdC, delta -fnr, delta -pta, delta -pflB, delta -leuA, delta -ilvE, delta -poxB and/or delta -ilvA, and comprises an expression or increased expression of kivd, ThrABC and adh2, where (C2) produces isobutanol; delta -adhE, delta -ldhA, delta -pta, delta -poxB, delta -ilvB, delta -ilvI, delta -metA and/or delta -tdh, and comprises an expression or increased expression of kivd, ThrABC, cimA and adh2, where (C2) produces 1-butanol; delta -metA and/or delta -tdh, and comprises an expression or increased expression of kivd, ThrABC, cimA and adh2, where (C2) produces 2-methyl-1-butanol; delta -adhE, delta -ldhA, delta -frdB, delta -frdC, delta -fnr, delta -pta, delta -pflB, delta -ilvE and/or delta -tyrB, and comprises an expression or increased expression of kivd, ThrABC and adh2, where (C2) produces 3-methyl-1-butanol; or delta -adhE, delta -ldhA, delta -frdB, delta -frdC, delta -fnr, delta -pta, delta -pflB, delta -leuA, delta -ilvE, delta -poxB and/or delta -ilvA, and comprises an expression or increased expression of kivd, ThrABC and adh2, where (C2) produces 2-phenylethanol. The ThrABC comprises a feedback resistant thrA. (C3) further comprises at least one gene knockout or disruption encoding an enzyme, which is an ethanol dehydrogenase, a lactate dehydrogenase, a fumarate reductase, a phosphate acetyltransferase and/or a formate acetyltransferase.    TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation (Disclosed): (A) is prepared by introducing conservative substitutions into isolated citramalate synthase using standard techniques. EXAMPLE - No suitable example given.