Abstract: The present invention relates to a novel alcohol/aldehyde dehydrogenase (hereinafter referred to as AADH), a process for producing the same and a process for producing aldehydes, carboxylic acids and ketones, especially 2-keto-L-gulonic acid (hereinafter referred to as 2-KGA) utilizing said enzyme.

Abstract: The present invention relates to a novel alcohol/aldehyde dehydro-genase (hereinafter referred to as AADH), a process for producing the same and a process for producing aldehydes, carboxylic acids and ketones, especially 2-keto-L-gulonic acid (hereinafter referred to as 2-KGA) utilizing said enzyme.

Abstract: The present invention is directed to methods for the production of ascorbic acid by culturing organisms of the genus Prototheca and recovering ascorbic acid from the fermentation medium.

Abstract: An expression vector containing both a DNA encoding an L-sorbose dehydrogenase and a DNA encoding an L-sorbosone dehydrogenase; a transformant having an ability to produce 2-keto-L-gulonic acid (hereinafter 2KLGA) at high yields from D-sorbitol, which is prepared by transforming, with said expression vector, a microorganism capable of producing L-sorbose at high yields from D-sorbitol, which has no or low 2KLGA-decomposing activity or a host microorganism having, in addition to the above-mentioned properties, no or low L-idonic acid-producing activity; and a process for producing 2KLGA, which comprises culturing said transformant in a medium containing D-sorbitol. According to the present invention, 2KLGA useful for the production of L-ascorbic acid can be produced with ease and in larger amounts by a single operation of culture.

Abstract: The present invention relates to a process for the production of 2-keto-L-gulonic acid by fermentative conversion of L-sorbose and/or D-sorbitol. The present invention further relates to novel bacterial strains useful in this process.

Abstract: An expression vector containing both a DNA encoding an L-sorbose dehydrogenase and a DNA encoding an L-sorbosone dehydrogenase; a transformant having an ability to produce 2-keto-L-gulonic acid (hereinafter 2KLGA) at high yields from D-sorbitol, which is prepared by transforming, with said expression vector, a microorganism capable of producing L-sorbose at high yields from D-sorbitol, which has no or low 2KLGA-decomposing activity or a host microorganism having, in addition to the above-mentioned properties, no or low L-idonic acid-producing activity; and a process for producing 2KLGA, which comprises culturing said transformant in a medium containing D-sorbitol. According to the present invention, 2KLGA useful for the production of L-ascorbic acid can be produced with ease and in larger amounts by a single operation of culture.

Abstract: A method is disclosed for preparing 5-ketogluconate, which comprises the steps of:(a) genetically modifying a microorganism capable of microbiologically producing 5-ketogluconate to increase gluconate NADP.sup.+ -5-oxidoreductase gene expression of said microorganism;(b) culturing said microorganism in a medium to produce 5-ketogluconate; and(c) recovering 5-ketogluconate from said medium.

Abstract: Mutants of 2,5-diketo-D-gluconic acid reductase A an enzyme used to produce 2-keto-L-gluconic acid, a precursor of ascorbic acid (vitamin C), are prepared by site-directed mutagenesis. These mutants may exhibit one or more of the following characteristics: improved temperature stability, increased resistance to substrate inhibition, increased turnover of the substrate by the enzyme and increased affinity for the substrate.

Abstract: The present invention is directed to methods for the production of ascorbic acid by culturing organisms of the species C. protothecoides and recovering ascorbic acid from the fermentation medium.

Abstract: An aldehyde dehydrogenase having the physico-chemical properties: molecular weight: 91,000.+-.5,000; substrate specificity:active on aldehyde compounds; inhibition: by Cu.sup.2+, Zn.sup.2+, Ni.sup.2 + and ethylenediamine tetraacetic acid; optimum pH: 6.0-8.5; optimum temperature: 20.degree.-40.degree. C.; and stimulator: Ca.sup.2+ and pyrroloquinoline quinone, is derived from a microorganism belonging to the genus Gluconobacter. Said aldehyde dehydrogenase can be produced by cultivating a microorganism of the genus Gluconobacter which is capable of producing an aldehyde dehydrogenase having the above properties, in an aqueous nutrient medium under aerobic conditions, disrupting the cells of the microorganism and isolating and purifying the aldehyde dehydrogenase from the cell-free extract of the disrupted cells of the microorganism.

Abstract: A process is disclosed for preparing an organic acid and/or its salts from a solution obtained through fermentation. In this process, a pure carbohydrate-containing raw material is used. The acid-containing solution prepared by means of fermentation is supplied to a cell separation, and the acid-containing permeate is supplied to a protein precipitation, where it is mixed with a silicon-containing precipitant at temperatures between 2.degree. and 70.degree. C. The solution thus obtained is supplied to a protein separation, and the acid-containing permeate is concentrated and then supplied to a single- or multi-stage crystallization or a granulation.

Abstract: A novel L-sorbose dehydrogenase (SDH) and a novel L-sorbosone dehydrogenase both derived from Gluconobacter oxydans T-100, a DNA which encodes the SDH and/or SNDH, an expression vector which contains the DNA, a host cell transformed by the expression vector and a process for producing the SDH and/or SNDH, which comprises culturing the host cell in a medium and recovering the SDH and/or SNDH from the resulting culture. The SDH and SNDH of the present invention are useful enzymes having preferable properties for the production of 2-keto-L-gulonic acid, as well as L-ascorbic acid. According to the production method of the present invention, the SDH and SNDH having such preferable properties can be produced in large amounts by genetic engineering.

Abstract: In a microbial process for producing 2-keto-L-gulonic acid (hereinafter sometimes referred to as 2KGA) by fermentation or microbial cell reaction with at least one microorganism capable of producing 2KGA, wherein the improvement comprises taking out, from the fermentation broth or microbial cell reaction mixture, the produced 2KGA alone or together with a low molecular-weight cation as the counter ion by electrodialysis.

Abstract: A method for producing 2-keto-L-gulonic acid (hereinafter referred to as 2KGA) which comprises(1) culturing a microorganism capable of producing 2KGA from L-sorbose, in a liquid culture medium containing a substrate to produce 2KGA and(2) recovering the produced 2KGA, while recovering the microorganism in the culture broth,(3) inoculating the recovered microorganism to a new liquid culture medium for the following culture and(4) repeating said culture and recovering at least once.The present invention provides an industrially advantageous, versatile method for producing 2KGA that shortens the overall culture time, and reduces the amounts of starting medium materials and culture waste.

Abstract: A process for producing a saccharide carboxylic acid or a salt thereof characterized in that a microorganism belonging to the genus Pseudogluconobacter and capable of oxidizing a hydroxymethyl group and/or hemiacetal hydroxyl-associated carbon atom to a carboxyl group, or an artifact derived from the microorganism, is permitted to act on a hydroxymethyl and/or hemiacetal hydroxyl-containing saccharide or saccharide derivative to produce and accumulate the corresponding carboxylic acid and the carboxylic acid so accumulated is harvested and novel saccharide carboxylic acids produced by the above production method, and by the process, from a broad range of saccharides, saccharic acids having carboxyl groups derived from hydroxymethyl and/or hemiacetal OH groups can be produced with high selectivity and in good yield, the resultant saccharide acids are resistant to enzymatic degradation and have improved water solubility, among other characteristics.

Abstract: A process for producing a saccharide carboxylic acid or a salt thereof characterized in that a microorganism belonging to the genus Pseudogluconobacter and capable of oxidizing a hydroxymethyl group and/or hemiacetal hydroxyl-associated carbon atom to a carboxyl group, or an artifact derived from the microorganism, is permitted to act on a hydroxymethyl and/or hemiacetal hydroxyl-containing saccharide or saccharide derivative to produce and accumulate the corresponding carboxylic acid and the carboxylic acid so accumulated is harvested and novel saccharide carboxylic acids produced by the above production method, and by the process, from a broad range of saccharides, saccharic acids having carboxyl groups derived from hydroxymethyl and/or hemiacetal OH groups can be produced with high selectivity and in good yield, the resultant saccharide acids are resistant to enzymatic degradation and have improved water solubility, among other characteristics.

Abstract: A process for producing 2-keto-L-gulonic acid which comprises converting L-sorbose and/or D-sorbitol into 2-keto-L-gulonic acid with the aid of a microorganism or its cell free extract, said microorganism belonging to the species Gluconobacter oxydans capable of producing 2-keto-L-gulonic acid and having L-sorbose dehydrogenase activity. Also disclosed are specific microorganisms useful in such process.

Abstract: Microalgal biomass that comprises cells of Chlorella pyrenoidosa which contain greater than 2.0% by dry weight of L-ascorbic acid (Vitamin C), microorganisms and processes that form the biomass, and L-ascorbic acid enhanced animal feed compositions that contain the biomass are disclosed.

Abstract: 2-keto-L-gulonic acid is in high yield produced by contacting a microorganism of the genus Pseudogluconobacter, either as it is or after processing, with L-sorbose.

Abstract: A process for producing a saccharide carboxylic acid or a salt thereof characterized in that a microorganism belonging to the genus Pseudogluconobacter and capable of oxidizing a hydroxymethyl group and/or hemiacetal hydroxyl-associated carbon atom to a carboxyl group, or an artifact derived from the microorganism, is permitted to act on a hydroxymethyl and/or hemiacetal hydroxyl-containing saccharide or saccharide derivative to produce and accumulate the corresponding carboxylic acid and the carboxylic acid so accumulated is harvested and novel saccharide carboxylic acids produced by the above production method, and by the process, from a broad range of saccharides, saccharic acids having carboxyl groups derived from hydroxymethyl and/or hemiacetal OH groups can be produced with high selectivity and in good yield, the resultant saccharide acids are resistant to enzymatic degradation and have improved water solubility, among other characteristics.

Abstract: A novel coenzyme independent L-sorbosone dehydrogenase originating from a microorganism belonging to the genus Gluconobacter oxydans which acts on L-sorbosone to produce 2-keto-L-gulonic acid.The enzyme has the following physico-chemical properties:a) optimum pH: about 7.0,b) optimum temperature: about 30.degree. C. to about 40.degree. C.,c) molecular sturucture: consisting of one type of unit having a molecular weight of about 47,500.+-.5,000 as measured by sodium dodecyl sulfate polyacrylamide gel electrophoresis,d) thermostability: stable below 30.degree. C., ande) inhibition: by Cu.sup.2+ -ions.

Abstract: The present invention relates to a process for producing 2-keto-L-gulonic acid by fermentative conversion of D-sorbitol in high yield. 2-Keto-L-gulonic acid is an important intermediate for the production of L-ascorbic acid into which it can be converted.

Abstract: 2,5-Diketo-D-gluconic acid is prepared in high yield and in high broth concentration by cultivating newly isolated microorganisms of genus Erwinia in an aqueous nutrient medium in the presence of D-glucose. The production is also possibly by simple contact of said microorganisms or their processed products therefrom, with D-glucose.

Abstract: 2,5-Diketo-D-gluconic acid is prepared in high yield and in high broth concentration by cultivating newly isolated microorganisms of genus Erwinia in an aqueous nutrient medium in the presence of D-glucose. The production is also possible by simple contact of said microorganisms or their processed products therefrom, with D-glucose.

Abstract: A coenzyme-independent L-sorbosone dehydrogenase has been prepared from a microorganism belong to the genus Pseudomonas, which acts on L-sorbosone to produce 2-keto-L-gulonic acid. The enzyme is membrane bound and has a molecular weight of about 47,000 kDa. The enzyme is used to carry out the conversion of L-sorbosone to 2-keto-L-gulonic acid.

Abstract: A process of producing 2-keto-L-gulonic acid from sorbose via a recombinant bacteria including expression vectors and probes for producing said recombinant bacteria.

Abstract: The invention provides a process for preparing L-rhamnose by hydrolyzing a rhamnosidic bond of a glycoside having rhamnose in a terminal position, by enzymatically hydrolyzing the glucoside with an enzyme combination comprising biological structural material degrading enzyme and a naringinase preparation which has a higher rhamnosidase activity than beta-glucosidase activity. Preferably the enzyme combination having rhamnosidase activity together with additional enzyme activity is a selected partially purified enzyme preparation having high rhamnosidase activity and low glucosidase activity together with biological structural material degrading activity. More preferably the additional enzyme activity is derived from an enzyme of the group consisting of protease, lipase, pectinase, cellulase and hemicellulase.

Abstract: In recombinant microorganisms which were rendered capable of converting 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-keto-L-gulonic acid (2-KLG) by transfer of genetic material, the secondary metabolites and metabolic pathways leading to the metabolic diversion of 2-KLG and 2,5-DKG were determined, and the diversion of 2-KLG to L-iodonic acid (IA) or of 2,5-DKG to 5-keto-D-gluconate (5-KDH) was blocked.

Abstract: Methods for producing ascorbic acid using recombinant means comprising the transfer of genetic material by conjugation, a host cell lacking, entirely or to such an extent as not to be commercially useful, one or more enzymes in the metabolic path converting glucose to 2 keto-L-gulonic acid.

Abstract: A process for the preparation of 2-keto-L-gulonic acid (2-KLG) from 2,5-diketo-D-gluconic acid (2,5-DKG) using a DNA sequence encoding 2,5-DKG reductase. The 2-KLG is a precursor for the synthesis of ascorbic acid (Vitamin C).

Abstract: Improved production of ascorbic acid is obtained empolying Chlorella as a microorganism source and growing the culture under a controlled pattern of carbon source supply. Greatly improved ratios of ascorbic acid to total carbon supplied as well as enhanced ascorbic acid concentrations in the fermentor are obtained.C. pyrenoidosa UV101-158 was deposited at the A.T.C.C. on June 27, 1985 and given Accession No. 53170.

Abstract: 2-Keto-L-gulonic acid is separated from a fermented medium containing the calcium salt of 2-keto-L-gulonic acid, by carrying out the following operations: separation of insolubles; removal of inorganic cations; and separation of the 2-keto-L-gulonic acid.

Abstract: A process of producing 2-keto-L-gulonic acid by fermentative conversion of L-sorbose utilizing a fermentation system composed of component produced from a microorganism having the identifying characteristics of strain DSM No. 4025 and a yeast component.

Abstract: Disclosed is a fermentation process for the conversion of L-sorbose to 2-keto-L-gulonic acid, which is characterized in that a mixed culture of microorganisms is used, which comprises Gluconobacter oxydans and Bacillus megaterium.

Abstract: 2-Keto-L-gulonic acid is produced in a high yield by contacting L-sorbose with a microorganism of Pseudomonas sorbosoxidans, or a processed material thereof.

Abstract: Processes for the bioconversion production of L-ascorbic acid (Vitamin C), and to microorganisms (e.g., Candida Norvegensis MF-56, ATCC 20686 and Candida Norvegensis MF-78, ATCC 20732) and bioconversion media which are specifically adapted for such bioconversion.

Abstract: The present invention relates to novel enzyme having L-sorbosone dehydrogenase activity and a process for producing the same. This L-Sorbosone dehydrogenase enzyme provided by the present invention catalyzes the oxidation of L-sorbosone to 2-keto-L-gulonic acid in the presence of nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate as a coenzyme. 2-KGA is an important precursor for the production of vitamin C.

Abstract: 2-Keto-L-gulonic acid is produced in a high yield by contacting L-sorbose with a microorganism of Pseudomonas sorbosoxidans, or a processed material thereof.

Abstract: 2,5-Diketo-D-gluconic acid is prepared in high yield and in high broth concentration by cultivating newly isolated microorganisms of genus Erwinia in an aqueous nutrient medium in the presence of D-glucose. The production is also possible by simple contact of said microorganisms or their processed products therefrom, with D-glucose.

Abstract: An improved process for producing 2-keto-L-gulonic acid which comprises culturing a microorganism belonging to the genus Pseudogluconobacter which has an ability to oxidize L-sorbose to 2-keto-L-gulonic acid in a culture medium supplemented with a rare earth element in the presence of L-sorbose.

Abstract: 2-Keto-D-glucaric acid is produced in high yield by contacting raw material saccharides (e.g. D-glucose) with a bacterium belonging to the genus Pseudogluconobacter or processed matters thereof.

Abstract: A process for preparing an optically active mercapto compound having asymmetrical centers having the formula: ##STR1## in which R.sub.1 represents an alkyl group, R represents a hydrogen atom or an alkyl group, C* represents an asymmetric carbon, n represents the value of 1 or 2, is disclosed. The process involves the reaction of a cultured microorganism having the ability of asymmetrically hydrolyzing ester bonds of the raw material, thus eliminating the need for protecting free mercapto groups which are unstable in the reaction conditions. The optically active mercapto compound is useful as a raw material for producing a compound having medicinal effects such as antihypertensive activity.

Abstract: Recombinant plasmids containing the gene encoding 2,5-diketogluconic acid reductase are prepared and used to transform microorganisms. 2,5,DKG reductase is expressed by the microorganisms.

Abstract: A novel reductase is produced from a microorganism which belongs to genus Corynebacterium and is useful as a catalyst which catalizes, in the presence of NADPH, reduction of 2, 5-diketo-D-gluconic acid or its salts to 2-keto-L-gulonate or the corresponding salts thereof. It also catalizes reduction of 5-keto-D-fructose to sorbose, in the presence of NADPH.

Abstract: 2-Keto-L-gulonic acid is prepared directly from D-glucose by microbial conversion utilizing mixed culturing on a medium containing D-glucose, employing two kinds of microorganisms; the first, a 2,5-diketo-D-gluconic acid producing microorganism which belongs to genus Erwinia and the second, a 2-keto-L-gulonic acid producing microorganism which belongs to genus Brevibacterium or Corynebacterium. The incubation of the microorganisms in a medium containing D-glucose is used in the disclosed process. By-production of 2-keto-D-gluconic acid, the undesired isomer of the intended product is effectively prevented by employing mixed culturing because of the co-existence of both microorganisms in the medium during at least part of the entire cultivation. Namely, 2-keto-D-gluconic acid produced by the second microorganism is utilized by the first microorganism to produce 2,5-diketo-D-gluconic acid which is subsequently converted into 2-keto-L-gulonic acid by the second microorganism.

Abstract: Processes for the fermentation production of L-ascorbic acid (Vitamin C), and to microorganisms (e.g., Candida Norvegensis MF-56, ATCC 20686) and fermentation media which are specifically adapted for such fermentation.

Abstract: Fermentative or enzymatic production of 2-keto-L-gulonic acid from 2,5-diketo-D-gluconic acid using living or processed mutants, being defective in metabolizing 5-keto-D-gluconic acid and incapable of producing 2-keto-D-gluconic acid. The mutant is derived from 2-keto-L-gluconic acid producing microorganisms of genus Corynebacterium. The production is carried out in the presence of nitrates and/or hydrogen donors in a preliminarily sterilized fermentation broth in which a 2,5-diketo-D-gluconic acid producing microorganism of genus Gluconobacter or Erwinia has been cultivated.

Abstract: A process for producing polysaccharide consisting of a partially acetylated variable block copolymer of D-mannuronic and L-guluronic acid residues comprises growing a biologically pure culture of a Pseudomonas mendocina microorganism selected from the group consisting of NCIB 11687, 11688, and 11689 in an aqueous nutrient medium by submerged aerobic fermentation of an assimilable carbon source and recovering the polysaccharide. Biologically pure cultures of the organisms are another feature of the invention.

Abstract: A process is described for the production of D-glucosone from glucose. An aqueous solution of glucose is converted substantially completely to D-glucosone by an enzymatic oxidation while removing or utilizing co-produced hydrogen peroxide. D-glucosone is a useful intermediate product which may then be converted to a desired end product.

Abstract: A process of producing 2-keto-L-gulonic acid from sorbose via a recombinant bacteria including expression vectors and probes for producing said recombinant bacteria.