Abstract: A process for the preparation of dihydroxypyrimidine derivatives of the general formula: in which R1 and R2 are identical or different and are a hydrogen atom, aryl group, or a C1-C4-alkyl group or an aryl group, starting from a compound of the general formula: in which R2 has the meaning mentioned above and R3 is —CN or COOR4, in which R4 is a C1-C4-alkyl group.

Abstract: A biologically pure culture of microorganisms capable of converting RS-&agr;-piperazinecarboxamides into the corresponding R-&agr;-piperazinecarboxylic acid. R-&agr;-piperazinecarboxamides is the only nitrogen source.

Abstract: Substituted pyridines of the general formula: ##STR1## wherein R.sup.1 is hydroxyl or chlorine, and a) X is hydrogen or chlorine, R.sup.2 and R.sup.3 together are .dbd.O, R.sup.4 is a group of the formula --OR.sup.5 and R.sup.5 is hydrogen, C.sub.1 -C.sub.4 -alkyl or benzyl orb) X is hydrogen and R.sup.2, R.sup.3 and R.sup.4 together are .dbd.N--NH--, orc) X and R.sup.2 each is hydrogen and R.sup.3 and R.sup.4 together are --O--, ord) X and R.sup.2 each is hydrogen, R.sup.3 is hydroxyl and R.sup.4 is amino or hydroxy.The compounds are obtained by subjecting nicotine to microbiological oxidation to give 5-succinoyl-2-pyridone, followed by chemical reactions. The compounds are suitable as intermediates for the preparation of pharmaceutically active compounds.

Abstract: Microorganisms of interest are capable of utilizing .alpha.-imino carboxamides, in the form of the racemate or of its optically active isomers, of the general formula ##STR1## wherein A together with --NH-- and --CH-- is an optionally substituted 5- or 6-membered saturated heterocyclic ring, as sole nitrogen source, and converting (RS)-.alpha.-imino carboxamides of Formula I into an S-.alpha.-imino carboxylic acid of the general formula ##STR2## These microorganisms are useful also for biconversion of an (RS)-.alpha.-imino carboxamide of Formula I into an S-.alpha.-imino carboxylic acid.

Abstract: Substituted pyridines of the general formula: ##STR1## wherein R.sup.1 is hydroxyl or chlorine, and a) X is hydrogen or chlorine, R.sup.2 and R.sup.3 together are .dbd.O, R.sup.4 is a group of the formula --OR.sup.5 and R.sup.5 is hydrogen, C.sub.1 -C.sub.4 -alkyl or benzyl, orb) X is hydrogen and R.sup.2, R.sup.3 and R.sup.4 together are .dbd.N--NH--, orc) X and R.sup.2 each is hydrogen and R.sup.3 and R.sup.4 together are --O--, ord) X and R.sup.2 each is hydrogen, R.sup.3 is hydroxyl and R.sup.4 is amino or hydroxyl.The compounds are obtained by subjecting nicotine to microbiological oxidation to give 5-succinoyl-2-pyridone, followed by chemical reactions. The compounds are suitable as intermediates for the preparation of pharmaceutically active compounds.

Abstract: A microbiological process for the preparation of a heteroaromatic carboxylic acid or one of its physiologically tolerated salts of the formulae I or II: ##STR1## wherein R.sub.1 and R.sub.2 are identical or different and each denotes a hydrogen or halogen atom, and X denotes a nitrogen atom or CH--, from a heteroaromatic nitrile of the formulae III or IV, respectively: ##STR2## First, a microorganism, Alcaligenes faecalis (DSM 6335), is cultured in the presence of an inducer, 2-cyanopyridine, and a carbon source such as a dicarboxylic acid, a tricarboxylic acid or a carbohydrate. Substrate III or IV is then reacted with the cultured microorganism. The biotransformation is carried out under anaerobic conditions for compounds of the formula I, and under aerobic conditions for compounds of the formula II.

Abstract: Microorganisms of interest are capable of utilizing .alpha.-imino carboxamides, in the form of the racemate or of its optically active isomers, of the general formula ##STR1## wherein A together with --NH-- and --CH-- is an optionally substituted 5- or 6-membered saturated heterocyclic ring, as sole nitrogen source, and converting (RS)-.alpha.-imino carboximides of Formula I into an S-.alpha.-amino carboxylic acid of the general formula ##STR2## These microorganisms are useful also for biconversion of an (RS)-.alpha.-imino carboxamide of Formula I into an S-.alpha.-amino carboxylic acid.

Abstract: A 2-halo-pyrimidine-4-carboxylic acid of formula: ##STR1## wherein X is a halogen atom, for example, 2-chloro-pyrimidine-4-carboxylic acid. A 2-substituted-pyrimidine-4-carboxylic acid derivative of formula: ##STR2## wherein R.sub.1 is a halogen atom, NH.sub.2 --, HO-- or a C.sub.1 -C.sub.4 alkoxy group and R.sub.2 is a C.sub.1 -C.sub.4 alkoxy group or a halogen atom with the proviso that, if R.sub.1 is a HO-- group, R.sub.2 is not a halogen atom and with the proviso that, if R.sub.2 is a halo group, R.sub.1 is not an amino group. A 2-substituted-pyrimidine-4-carboxylic acid derivative of formula III wherein R.sub.1 is a HO-- group and R.sub.2 is an ethoxy group.

Abstract: The microbiological process for the production of hydroxy-heterocyclic carboxylic acid of formula ##STR1## wherein R.sub.1 means a hydrogen or a halogen atom and X means a nitrogen atom or a CR.sub.2 function, wherein R.sub.2 means a hydrogen or halogen atom, starting from the corresponding heterocyclic carboxylic acid. The process is performed so that an aerobic biomass which utilizes nicotinic acid, is cultivated in a molar ratio of nicotinic acid to mineral acid of 1 to 8. The ratio is assured over the entire cultivation phase. The the hydroxylation of the corresponding heterocyclic carboxylic acid of the general formula ##STR2## wherein R.sub.1 and X have the above-mentioned meanings, is performed with the biomass. Under these conditions, strain Pseudomonas acidovorans DSM 7205, strain Pseudomonas acidovorans DSM 7203, strain Alcaligenes faecalis DSM 7204 and strain Arthrobacter crystallopoietes DSM 7202 are concentrated in the cultivation phase.

Abstract: A new microbiological process for the production of hydroxy-nitrogen-heterocyclic-carboxylic acids or their soluble salts of the general formula: ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and each is a hydrogen atom, a halogen atom or a C.sub.1 -C.sub.4 alkyl group and X is a nitrogen atom or a CR.sub.3 function, wherein R.sub.3 is a hydrogen atom or a halogen atom, starting from the corresponding nitrogen-heterocyclic-carboxylic acids, as well as new microorganisms suitable for use in the process.

Abstract: A microbiological process for the production of 5-hydroxypyrazinecarboxylic acid and/or its salts with microorganisms of the strain Agrobacterium sp. DSM 6336 or descendants thereof or mutants thereof, utilizing 3-cyanopyridine.

Abstract: A new microbiological process for the production of hydroxy-nitrogen-heterocyclic-carboxylic acids or their soluble salts of the general formula: ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and each is a hydrogen atom, a halogen atom or a C.sub.1 -C.sub.4 alkyl group and X is a nitrogen atom or a CR.sub.3 function, wherein R.sub.3 is a hydrogen atom or a halogen atom, starting from the corresponding nitrogen-heterocyclic-carboxylic acids, as well as new microorganisms suitable for use in the process.

Abstract: A microbiological process for terminal hydroxylation of ethyl groups on aromatic 5- or 6-member ring heterocycles. The hydroxylation is performed with microorganisms which:(a) contain the genes of a Pseudomonas OCT plasmid which form an active alkane monooxygenase, and(b) form no active chromosomal or plasmid-coded alcohol dehydrogenase.

Abstract: Microorganisms which are capable of growing with 2,5-dimethylpyrazine as the sole carbon, nitrogen and energy source. These microorganisms hydroxylate heterocycles of general formula: ##STR1## to heterocycles of general formula: ##STR2## The latter compounds are accumulated in the growth medium.

Abstract: A microbiological process for the production of 5-hydroxypyrazinecarboxylic acid and/or its salts with microorganisms using nicotinic acid and/or its salts.

Abstract: The invention is a biologically pure culture of Alcaligenes faecalis DSM 6335. Furthermore, the culture or a mutant thereof, is capable of growing with 2-cyanopyridine as the sole carbon, nitrogen and energy source in order to produce 6-hydroxypicolinic acid. The specific reaction is the conversion of 2-cyanopyridine as the substrate into 6-hydroxypicolinic acid.

Abstract: A microbiological process for the production of 6-hydroxypicolinic acid starting from picolinic acid and/or its salts. The concentration of picolinic acid and/or its salts is selected so that the 6-hydroxypicolinic acid is not further metabolized. The process is performed either by microorganisms of genus Pseudomonas, Bacillus, Alcaligenes, Aerococcus, or Rhodotorula, or with biomass using picolinic acid, which grow with picolinic acid as the sole carbon, nitrogen and energy source.

Abstract: A microbiological process for the production of 6-hydroxynicotinic acid starting from 3-cyanopyridine. For this process, new microorganisms are used, which are capable of growing with 3-cyanopyridine as the sole carbon, nitrogen and energy source and of biotransforming it as substrate in 6-hydroxynicotinic acid.

Abstract: Microorganisms, which are capable of growing with pyrazine as the sole carbon, nitrogen and energy source. These microorganisms hydroxylate pyrazine derivatives of general formula: ##STR1## to hydroxylated pyrazine derivatives of general formula: ##STR2## and the latter are accumulated in the growth medium.

Abstract: A microbiological process for the production of 6-hydroxypicolinic acid starting from 2-cyanopyridine. For this process new microorganisms are used, which are capable of growing with 2-cyanopyridine as the sole carbon, nitrogen and energy source and of converting it as the substrate into 6-hydroxypicolinic acid.