Two NADPH-dependent 2-ketogluconate reductases involved in 2-ketogluconate assimilation in sp. strain CHM43.

Unlabelled: Incomplete oxidation of glucose by sp. strain CHM43 produces gluconic acid and then 2- or 5-ketogluconic acid. Although 2-keto-D-gluconate (2KG) is a valuable compound, it is sometimes consumed by itself via an unknown metabolic pathway.

Membrane-bound D-mannose isomerase of acetic acid bacteria: finding, characterization, and application.

D-Mannose isomerase (EC 5.3.1.

Relocation of dehydroquinate dehydratase to the periplasmic space improves dehydroshikimate production with Gluconobacter oxydans strain NBRC3244.

3-Dehydroshikimate (3-DHS) is a key intermediate for the synthesis of various compounds, including the antiviral drug oseltamivir. The Gluconobacter oxydans strain NBRC3244 intrinsically oxidizes quinate to produce 3-dehydroquinate (3-DHQ) in the periplasmic space. Even though a considerable activity is detected in the recombinant G.

The 5-Ketofructose Reductase of sp. Strain CHM43 Is a Novel Class in the Shikimate Dehydrogenase Family.

sp. strain CHM43 oxidizes mannitol to fructose and then oxidizes fructose to 5-keto-d-fructose (5KF) in the periplasmic space. Since NADPH-dependent 5KF reductase was found in the soluble fraction of spp.

Characterization of a cryptic, pyrroloquinoline quinone-dependent dehydrogenase of Gluconobacter sp. strain CHM43.

We characterized the pyrroloquinoline quinone (PQQ)-dependent dehydrogenase 9 (PQQ-DH9) of Gluconobacter sp. strain CHM43, which is a homolog of PQQ-dependent glycerol dehydrogenase (GLDH). We used a plasmid construct to express PQQ-DH9.

Three ATP-dependent phosphorylating enzymes in the first committed step of dihydroxyacetone metabolism in Gluconobacter thailandicus NBRC3255.

Dihydroxyacetone (DHA), a chemical suntan agent, is produced by the regiospecific oxidation of glycerol with Gluconobacter thailandicus NBRC3255. However, this microorganism consumes DHA produced in the culture medium. Here, we attempted to understand the pathway for DHA metabolism in NBRC3255 to minimize DHA degradation.

Taro of enabling hydrolysis of konjac polysaccharides to various biotechnological interest.

Due to the indigestibility, utilization of konjac taro, has been limited only to the Japanese traditional konjac food. preparation with konjac taro was examined to utilize konjac taro as a source of utilizable carbohydrates. AKU 3302 was selected as a favorable strain for preparation, while used extensively in brewing industry was not so effective.

5-Keto-D-fructose production from sugar alcohol by isolated wild strain CHM 43.

CHM 43 have D-mannitol dehydrogenase (quinoprotein glycerol dehydrogenase) and flavoprotein D-fructose dehydrogenase in the membranes. When the two enzymes are functional, D-mannitol is converted to 5-keto-D-fructose with 65% yield when cultivated on D-mannitol. 5-Keto-D-fructose production with almost 100% yield was realized with the resting cells.

The membrane-bound sorbosone dehydrogenase of Gluconacetobacter liquefaciens is a pyrroloquinoline quinone-dependent enzyme.

Membrane-bound sorbosone dehydrogenase (SNDH) of Gluconacetobacter liquefaciens oxidizes l-sorbosone to 2-keto-l-gulonic acid (2KGLA), a key intermediate in vitamin C production. We constructed recombinant Escherichia coli and Gluconobacter strains harboring plasmids carrying the sndh gene from Ga. liquefaciens strain RCTMR10 to identify the prosthetic group of SNDH.

Aldopentoses as new substrates for the membrane-bound, pyrroloquinoline quinone-dependent glycerol (polyol) dehydrogenase of Gluconobacter sp.

Membrane-bound, pyrroloquinoline quinone (PQQ)-dependent glycerol dehydrogenase (GLDH, or polyol dehydrogenase) of Gluconobacter sp. oxidizes various secondary alcohols to produce the corresponding ketones, such as oxidation of D-sorbitol to L-sorbose in vitamin C production. Substrate specificity of GLDH is considered limited to secondary alcohols in the D-erythro configuration at the next to the last carbon.

Improved heterologous expression of the membrane-bound quinoprotein quinate dehydrogenase from Gluconobacter oxydans.

Gluconobacter oxydans produces 3-dehydroquinate by oxidation of quinate through a reaction catalyzed by the quinate dehydrogenase (QDH), membrane-bound, pyrroloquinoline quinone (PQQ)-dependent dehydrogenase. We previously reported the nucleotide and deduced amino acid sequence of QDH and constructed a heterologous expression system of QDH in Pseudomonas sp. (A.

Membrane-bound glycerol dehydrogenase catalyzes oxidation of D-pentonates to 4-keto-D-pentonates, D-fructose to 5-keto-D-fructose, and D-psicose to 5-keto-D-psicose.

A novel oxidation of D-pentonates to 4-keto-D-pentonates was analyzed with Gluconobacter thailandicus NBRC 3258. D-Pentonate 4-dehydrogenase activity in the membrane fraction was readily inactivated by EDTA and it was reactivated by the addition of PQQ and Ca. D-Pentonate 4-dehydrogenase was purified to two different subunits, 80 and 14 kDa.

Reduction of L-phenylalanine in protein hydrolysates using L-phenylalanine ammonia-lyase from Rhodosporidium toruloides.

L-Phenylalanine ammonia-lyase (PAL, EC 4.3.1.

Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product.

Replacement of a terminal cytochrome c oxidase by ubiquinol oxidase during the evolution of acetic acid bacteria.

The bacterial aerobic respiratory chain has a terminal oxidase of the heme-copper oxidase superfamily, comprised of cytochrome c oxidase (COX) and ubiquinol oxidase (UOX); UOX evolved from COX. Acetobacter pasteurianus, an α-Proteobacterial acetic acid bacterium (AAB), produces UOX but not COX, although it has a partial COX gene cluster, ctaBD and ctaA, in addition to the UOX operon cyaBACD. We expressed ctaB and ctaA genes of A.

Overexpression of a type II 3-dehydroquinate dehydratase enhances the biotransformation of quinate to 3-dehydroshikimate in Gluconobacter oxydans.

Shikimate and 3-dehydroshikimate are useful chemical intermediates for the synthesis of various compounds, including the antiviral drug oseltamivir. Here, we show an almost stoichiometric biotransformation of quinate to 3-dehydroshikimate by an engineered Gluconobacter oxydans strain. Even under pH control, 3-dehydroshikimate was barely detected during the growth of the wild-type G.

Pentose oxidation by acetic acid bacteria led to a finding of membrane-bound purine nucleosidase.

D-Ribose and 2-deoxy-D-ribose were oxidized to 4-keto-D-ribonate and 2-deoxy-4-keto-D-ribonate respectively by oxidative fermentation, and the chemical structures of the oxidation products were confirmed to be as expected. Both pentoses are important sugar components of nucleic acids. When examined, purine nucleosidase activity predominated in the membrane fraction of acetic acid bacteria.

Draft Genome Sequence of Dihydroxyacetone-Producing Gluconobacter thailandicus Strain NBRC 3255.

Here, we report the draft genome sequence of the acetic acid bacterium Glucnobacter thailandicus strain NBRC 3255. The draft genome sequence is composed of 109 contigs in 3,305,227 bp and contains 3,225 protein-coding genes. Two paralogous sets of sldAB operons, which are responsible for dihydroxyacetone production from glycerol, were identified.

Characterization of genes involved in D-sorbitol oxidation in thermotolerant Gluconobacter frateurii.

Further upstream of sldSLC, genes for FAD-dependent D-sorbitol dehydrogenase in Gluconobacter frateurii, three additional genes (sldR, xdhA, and perA) are found: for a transcriptional regulator, NAD(P)-dependent xylitol dehydrogenase, and a transporter protein, a member of major facilitator superfamily, respectively. xdhA and perA but not sldR were found to be in the same transcriptional unit. Disruption of sldR resulted in a dramatic decrease in sldSLC promoter activity, indicating that it is an activator for sldSLC expression.

High-temperature sorbose fermentation with thermotolerant Gluconobacter frateurii CHM43 and its mutant strain adapted to higher temperature.

We succeeded in obtaining a strain adapted to higher temperature from a thermotolerant strain, Gluconobacter frateurii CHM43, for sorbose fermentation. The adapted strain showed higher growth and L-sorbose production than original CHM43 strain at higher temperature around 38.5-40 °C.

Enzymatic synthesis of 4-pentulosonate (4-keto-D-pentonate) from D-aldopentose and D-pentonate by two different pathways using membrane enzymes of acetic acid bacteria.

4-Keto-D-arabonate (D-threo-pent-4-ulosonate) and 4-keto-D-ribonate (D-erythro-pent-4-ulosonate) were prepared from D-arabinose and D-ribose by two successive reactions of membrane-bound enzymes, D-aldopentose 4-dehydrogenase and 4-keto-D-aldopentose 1-dehydrogenase of Gluconobacter suboxydans IFO 12528. Alternatively, they were prepared from D-arabonate and D-ribonate with another membrane-bound enzyme, D-pentonate 4-dehydrogenase. Analytical data confirmed the chemical structures of the 4-pentulosonates prepared.

Global analysis of the genes involved in the thermotolerance mechanism of thermotolerant Acetobacter tropicalis SKU1100.

Acetobacter tropicalis SKU1100 is a thermotolerant acetic acid bacterium that grows even at 42 °C, a much higher temperature than the limit for the growth of mesophilic strains. To elucidate the mechanism underlying the thermotolerance of this strain, we attempted to identify the genes essential for growth at high temperature by transposon (Tn10) mutagenesis followed by gene or genome analysis. Among the 4,000 Tn10-inserted mutants obtained, 32 exhibited a growth phenotype comparable to that of the parent strain at 30 °C but not at higher temperatures.

Formation of 4-keto-D-aldopentoses and 4-pentulosonates (4-keto-D-pentonates) with unidentified membrane-bound enzymes from acetic acid bacteria.

In our previous study, a new microbial reaction yielding 4-keto-D-arabonate from 2,5-diketo-D-gluconate was identified with Gluconacetobacter liquefaciens RCTMR 10. It appeared that decarboxylation and dehydrogenation took place together in the reaction. To analyze the nature of the reaction, investigations were done with the membrane fraction of the organism, and 4-keto-D-arabinose was confirmed as the direct precursor of 4-keto-D-arabonate.

Selective, high conversion of D-glucose to 5-keto-D-gluoconate by Gluconobacter suboxydans.

Selective, high-yield production of 5-keto-D-gluconate (5KGA) from D-glucose by Gluconobacter was achieved without genetic modification. 5KGA production by Gluconobacter suffers byproduct formation of 2-keto-D-gluconate (2KGA). By controlling the medium pH strictly in a range of pH 3.