Degussa Aktiengesellschaft

Deutsche Gold- Und Silber-Scheideanstalt Vormals Roessler

Kernforschungsanlage Julich

Society for Biotechnical Research

Degussa Aktiengelleschaft

Gesellschaft Fur Biotechnologisch Forschung

Degussa Aktiengesellschaft and Gesellschaft Fur Biotechnologische

Wolfgang Leuchtenberger

Maria-Regina Kula

Werner Hummel

Horst Schutte

Christian Wandrey

Axel Kleemann

Werner Schwarze

Ulrich Groeger

Rolf Wichmann

Karlheinz Drauz

Walter Pfefferle

Michael Karrenbauer

Andreas Buckmann

Manfred Kircher

Hermann Sahm

Gerd Schreyer

Lothar Eggeling

Herbert Klenk

Heinz Friedrich

Horst Weigel

Jurgen Martens

Herbert Tanner

Hermann Lotter

Wolfram Binder

Heinz Haschke

Rudi E Moerck

Wolf-Dieter Deckwer

Eberhard Breuker

Toshihisa Ohshima

Rudi Moerck

Elisabeth Scheer

Kurt Klostermann

Henning Holldorff

Harald Voss

Holger Werning

Bernhard Schilling

Bernd Bachmann

Bernhard Muetze

A method of producing L-amino acids by fermentation. Microorganisms of the genus Corynebacterium which exhibit an auxotrophy relative to an amino acid are used as biocatalysts. The method is characterized in that the carbon source on the one hand and the limiting amino acid on the other hand are fed in two or more different infeed currents to the process. The infeed profiles have, for example, a concave (saccharose) and an exponential (amino acid) form or a convex (saccharose) and likewise a convex (amino acid) form, with specific differing degrees of increase of the currents relative to each other over time.

Method of producing L-amino acids by fermentation

The invention is relates to improved stirred-tank reactors which are suitable, due to special fittings, for converting the results of e.g. microbial or enzymatic processes obtained when they are used on a laboratory scale into an industrial scale. A shaft-driven disk agitator is provided, with at least one perforated disk being attached in the reactor above and/or below the disk agitator.

Stirred-tank reactors and method of use

An animal feed supplement and processes for its production which provide an inexpensive, not excessively hygroscopic or sticky supplement amino acid whose content should be standardizable. The animal feed supplement is based on a fermentation broth and contains the predominant proportion of its contents, optionally with the exclusion of part of the biomass. The biomass is preferably present in an amount of at most 10% by weight in the dry state. Proteins are preferably present in a maximum amount of 10% by weight. For the production, the sugar content is adjusted to a maximum of 4 g/l during fermentation, at least towards the end thereof, and at least part of the biomass is optionally removed during the working up.

Animal feed supplement based on a fermentation broth amino acid, a

The invention is directed to obtaining phenylalanine-dehydrogenase containing microorganisms by a special selection process comprising obtaining microorganisms, especially strains of Rhodococcus and the phenylalanine-dehydrogenase obtained in them. With the help of this enzyme there are obtained L-.alpha.-aminoacids from the corresponding ketocarboxylic acids by reductive amination.

Rhodococcus microorganisms that produce phenylalanine dehydroganase

A microbiologically produced, thermostable N-acylproline-acylase and a process for obtaining it from Comamonas testosteroni DSM 5416 and Alcaligenes denitrificans DSM 5417. The enzyme is useful for the synthesis of L-proline from various N-acyl-L-proline derivatives.

Method of making L-proline using an N-acyl-L-protine acylase

The invention is directed to a method of producing L-amino acids from .alpha.-ketocarboxylic acids by means of continuous fermentation with the aid of glutamate producing bacteria with biomass retention in which the cells are separated by microfiltration and/or centrifugal separators.

Method for the fermentative production of L-amino acids from

A substantially purified N-acyl-L-proline-acylase from Comamonas testosteroni DSM 5416 and Alcaligenes denitrificans DSM 5417. The enzyme is useful for the synthesis of L-proline from various N-acyl-L-proline derivatives.

Substantially purified N-acyl-L-proline acylase from Comamonas

A method for the fermentative production of L-isoleucine from D,L-.alpha.-hydroxybutyrate by means of mutants of the genus Corynbecaterium which utilize D-lactate.

Method for the fermentative production of L-isoleucine from

The preparation of an L-amino acid, particularly valine, leucine, isoleucine, alanine and phenylalanine, from the corresponding .alpha.-keto carboxylic acid by bacterial fermentation in the presence of ammonium ions is carried out with the aid of thermophilic Bacillus strains at temperatures above 45.degree. C., in particular above 60.degree. C. Bacillus strains DSM 406, 452, 461, 42, 463, 465 and 466 are particularly suitable for this purpose. The greater solubility of the amino acid at the elevated fermentation temperature permits the separation out of the amino acid from the reaction mixture simply by cooling, whereafter the depleted reaction mixture can be pumped back into the fermenter. Especially favorable yields are achieved by supplying oxygen to the fermenter to an amount of less than about 20% dissolved oxygen.

Process for the fermentative preparation of L-amino acids from

A microbiologically produced .alpha.-acetylamino cinnamic acid acylase and a method for its production from Brevibacterium species NCIB 12246 or NCIB 12247. The new enzyme can be used as constituent of a coupled enzyme system for enzymatic conversions which run via the intermediary stage .alpha.-imino-.beta.-phenylpropionic acid or phenylpyruvic acid.

Microbiologically produced .alpha.-acetylamino cinnamic acid acylase,

L-amino acids present in cleavage solutions obtained in the acylase-catalyzed cleavage of N-acetyl-D,L-amino acids are isolated by use of a strongly acidic ion exchanger in H+ form. First, the mother liquor from a previous treatment cycle is fed to the ion exchanger, and then the cleavage solution and finally the wash water and the discharge from the ion exchanger which is pH-controlled is analyzed into an 'effluent water fraction', an 'N-acetyl-D-amino acid fraction' and an 'L-amino acid fraction'. The last fraction is adjusted by addition of fresh cleavage solution to a pH of between 4.0 and 6.0, and from the mixture which is thus obtained the L-amino acid is isolated by crystallization. The mother liquor which is obtained is recycled back into a subsequent treatment cycle.

Process for the isolation of L-amino acids

The subject matter of the invention is a new D(-)-mandelate-dehydrogenase and obtaining it from Lactobacillus curvatus DSM 20019 (obtainable from the German Collection of Microorganisms). The new enzyme can be used for the enzymatic conversion of D(-)-mandelic acid and various other D-2-hydroxycarboxylic acids into the corresponding 2-ketocarboxylic acids or from benzoyl formate and various other 2-ketocarboxylic acids conversion to the corresponding D-2-hydroxycarboxylic acids.

Microbiologically produced d(-)-mandelate-dehydrogenase process for

.alpha.-Hydroxycarboxylic acids are continuously converted into the corresponding optically active .alpha.- aminocarboxylic acids. The conversion is carried out in a membrane reactor in the presence of nicotinamide-adenine dinucleotide increased in molecular weight by bonding to a water soluble high molecular weight material, a dehydrogenase specific for the .alpha.-hydroxycarboxylic acid, a dehydrogenase specific for the corresponding .alpha.-amino-carboxylic acid and ammonium ions. There is continuously supplied to the membrane reactor an aqueous solution of the .alpha.-hydroxycarboxylic acid to be reacted, a substantially lesser amount of the corresponding .alpha.-ketocarboxy lic acid, and an amount of ammonium ion at least equivalent to the .alpha.-hydroxycarboxylic acid to be reacted. There is maintained over the membrane a difference in pressure 1 and 15 bar. Behind the membrane, there is continuously drawn off a filtrate stream containing the .alpha.-aminocarboxylic acid formed.

Process for the continuous enzymatic conversion of alpha-hydrocarboxylic

The reaction mixture obtained in the enzymatic reaction of fumaric acid to form L-malic acid contains the L-malic acid and unreacted fumaric acid as their salts. To recover pure solutions of L-malic acid the reaction mixture is treated at 50.degree. to 150.degree. C. with cation exchangers. The eluate after concentration to 30 to 80 weight % content of L-malic acid is filtered. The pure L-malic acid is recovered by evaporating the solutions, in a given case after treatment with activated carbon.

Process for the recovery of malic acid

The enzyme D-2-hydroxy-4-methylpentanoic acid dehydrogenase has been prepared by culturing readily available Lactobacillus or Leuconostoc, microorganisms, such as Lactobacillus casei ssp. pseudoplantarum and Leuconostoc mesenteroides. The microbiologically produced enzyme has special characteristics and is capable of converting D-2-hydroxycarboxylic acids, such as D-2-hydroxy-4-methylpentanoic acid to the corresponding 2-ketocarboxylic acid and is capable of enzymatically converting 2-ketocarboxylic acids, such as 2-keto-4-methylpentanoic acid and 2-ketobutyric acid to the corresponding D-2-hydroxycarboxylic acid.

Microbiologically produced D-2-hydroxy-4-methylpentanoic acid

Growing community of inventors

Bruchkobel, Germany

Wolfgang Leuchtenberger