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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. The expression host was a derivative strain of CHM43, which lacked the genes for GLDH and the membrane-bound alcohol dehydrogenase and consequently had minimal ability to oxidize primary and secondary alcohols. The membranes of the transformant exhibited considerable d -arabitol dehydrogenase activity, whereas the reference strain did not, even if it had PQQ-DH9-encoding genes in the chromosome and harbored the empty vector. This suggests that PQQ-DH9 is not expressed in the genome. The activities of the membranes containing PQQ-DH9 and GLDH suggested that similar to GLDH, PQQ-DH9 oxidized a wide variety of secondary alcohols but had higher Michaelis constants than GLDH with regard to linear substrates such as glycerol. Cyclic substrates such as cis -1,2-cyclohexanediol were readily oxidized by PQQ-DH9. [ABSTRACT FROM AUTHOR]

Due to the indigestibility, utilization of konjac taro, Amorphophallus konjac has been limited only to the Japanese traditional konjac food. Koji preparation with konjac taro was examined to utilize konjac taro as a source of utilizable carbohydrates. Aspergillus luchuensis AKU 3302 was selected as a favorable strain for koji preparation, while Aspergillus oryzae used extensively in sake brewing industry was not so effective. Asp. luchuensis grew well over steamed konjac taro by extending hyphae with least conidia formation. Koji preparation was completed after 3-day incubation at 30°C. D-Mannose and D-glucose were the major monosaccharides found in a hydrolyzate giving the total sugar yield of 50 g from 100 g of dried konjac taro. An apparent extent of konjac taro hydrolysis at 55°C for 24 h seemed to be completed. Since konjac taro is hydrolyzed into monosaccharides, utilization of konjac taro carbohydrates may become possible to various products of biotechnological interest. Plausible applications of konjac mannan into food, beverage, and chemical industries triggered by hydrolysis with konjac taro koji. [ABSTRACT FROM AUTHOR]

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 method proposed here should give a smart strategy for 5-keto-D-fructose production. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the physicochemical and kinetic properties of chlorogenate hydrolase (CHase) (EC 3.1.1.42) of Aspergillus niger AKU 3302 by induction in the presence of yerba mate extract. The data obtained could be applicable directly to mass processing for a plant scale production of quinic acid (QA) and caffeic acid (CA) with koji CHase. It is fundamentally significant to accumulate catalytic properties of CHase as much as possible with crude CHase, when koji CHase is directed to practical industrial processing of breakdown of chlorogenate (CGA). CHase exhibited a high thermal stability without appreciable loss after standing for 6 h at 50 °C and was stable in wide pH ranges from 2.0 to 9.0. The optimum pH and temperature of CHase activity were found at 6.5–7.0 and 45 °C, respectively. The V max and K m values for CGA hydrolysis were 1.996 unit mg −1 and 0.72 mM, respectively. The activation energy of CHase was estimated to be 26 kJ mol −1 . Thus, CHase induced with CGA revealed successful for the production of CA and QA, fine chemicals of high interest and commercial values, from natural plant resources rich in CGA such as yerba mate. Several advantageous merits obtained with a crude CHase for the practical formation of QA and CA from yerba mate or yerba mate extract are discussed. [ABSTRACT FROM AUTHOR]

A novel oxidation of D-pentonates to 4-keto-D-pentonates was analyzed withGluconobacter thailandicusNBRC 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 Ca2+. D-Pentonate 4-dehydrogenase was purified to two different subunits, 80 and 14 kDa. The absorption spectrum of the purified enzyme showed no typical absorbance over the visible regions. The enzyme oxidized D-pentonates to 4-keto-D-pentonates at the optimum pH of 4.0. In addition, the enzyme oxidized D-fructose to 5-keto-D-fructose, D-psicose to 5-keto-D-psicose, including the other polyols such as, glycerol, D-ribitol, D-arabitol, and D-sorbitol. Thus, D-pentonate 4-dehydrogenase was found to be identical with glycerol dehydrogenase (GLDH), a major polyol dehydrogenase inGluconobacterspecies. The reaction versatility of quinoprotein GLDH was notified in this study. [ABSTRACT FROM AUTHOR]

The potential of yerba mate ( Ilex paraguariensis ) to induce chlorogenate hydrolase (EC 3.1.1.42, CHase) activity in different fungal strains has been investigated. CHase was highly induced in mycelia of Aspergillus niger AKU 3302 grown in Czapek medium containing yerba mate extract as inducer. Different materials derived from yerba mate processing were examined as CHase activity inducers. All yerba mate samples produced CHase activity and a concentrated aqueous yerba mate extract was selected as the most convenient inducer. A response surface methodology was used to assess the simultaneous effect of inducer concentration and induction duration on enzyme production. The experimental design revealed that the optimum CHase production was achieved after long induction times (≥25 h) and low inducer concentrations (0.1–0.2% w/v, dry basis). [ABSTRACT FROM AUTHOR]

The article discusses the findings of a study which determined the role of genes in oxidative fermentation of D-sorbitol in Gluconobacter frateurii bacteria. The researchers described the oxidizing characteristic of the Gluconobacter in producing L-sorbose, 2- and 5-keto-D-gluconates, and the Miglitol drug. The experiment confirmed the identification and characterization of D-sorbitol dehydrogenase genes including sldR, xdhA, and perA.

The article presents a study that attempts to identify the genes essential for growth at high temperature by transposon (Tn10) mutagenesis to elucidate the mechanism underlying the thermotolerance of mesophilic strains. It states that Acetobacter tropicalis SKU1100 is a thermotolerant acetic acid bacterium that dwells even at high temperatures. Results have further supported the partial overlap between the genes required for acetic acid resistance and those needed for thermotolerance.

The article presents a study concerning the formation of 4-Pentulosonates (4-Keto-D-pentonates) and 4-Keto-D-aldopentoses having unidentified membrane-bound enzymes coming from acetic acid bacteria. Study uses various methods to examine the formation including thin layer chromatography (TLC), centrifugation, and ethylenediaminetetraacetic acid (EDTA) treatment. Findings reveal the unidentified membrane-bound enzymes which contribute in the formation of 4-Pentulosonates and 4-Keto-D-aldopentoses.

The article presents a study on the production of 5-keto-D-gluconate (5KGA) derived from D-glucose by Gluconobacter. The study indicates that the effect of potential of hydrogen (pH) is essential in the production of 5KGA is correlative with the pH dependency of 5KGA. It notes that the 5KGA compound holds potential as an intermediate in the food industry.

The article focuses on the production of 4-keto-D-arabonate (4KAB) by Gluconacetobacter liquefaciens strains. It states that the strains accumulated 2,5-diketo-d-gluconate (25DKA) and oxidized D-gluconate, D-glucose, and 2-keto-D-gluconate (2KGA). It says that after the accumulation, 25DKA was converted into 4KAB and 4KAB remained stable in Gluconacetobacter liquefaciens. Moreover, a study of M. Ameyama and K. Kondo on carbohydrate metabolism of acetic acid bacteria assumed the 4KAB occurrence.

The article presents a study regarding the productiuon of 3-dehydroshikimate (DSA) from quinate by immobilixing the membrane fraction of the acetic acid bacteria Gluconobacter oxydans IFO 3244. The study used several methods to realize and examine the immobilization process including encapsulation, ionic binding, and physical adsorption. Results show a conversion rate of almost 100% from quinate to 3-dehydroshikimate.

The article presents a study concerning acetic acid fermentation of Acetobacter pasteurianus. The study involves the examination of the relationship between pellicle polysaccharide formation and acetic acid resistance. It shows that acetic acid resistance ability pellicle formation is primarily related to pellicle formation, thus is essential to acetic acid fermentation in A. pasteurianus strains.

The article presents a study that focuses on the purification and characterization of the membrane-bound 3-dehydroshikimate dehydratase (mDSD) and enzyme solubilization from the membrane fraction of gluconobacter oxydans IFO 3244. The results revealed that the mDSD in the membrane fraction suggests the mDSD's significance of aromatization, solubilized and purified to high homogeneity. It says that dehydroshikimate (DSA) was confirmed as a direct precursor of phenylcyclohexylamine (PCA).

The article discusses membrane-bound glucono-δ-lactonase (MGL) properties, solubility, and enzyme purification. It presents the process wherein MGL is purified from Gluconobacter oxydans. It also discusses that the involved acetic acid bacteria and aerobic bacteria in the oxidative fermentation contains a well-developed periplasmic oxydase system which yields bioenergy formation.

The article studies tightly-bound quinone functions in the ubiquinone reaction sites of the quinoprotein alcohol dehydrogenase (ADH) of the Gluconobacter suboxydans bacterium in acetic acid. It includes an in-depth analysis of the solubilization and purification of ADH with dodecyl maltoside, as well as a discussion on the issues' implications for biological chemistry.

The article presents a study which examines the purification and properties of dihydroxyacetone (DHA) reductases in gluconobacter suboxydans grown in gycerol. It states that two DHA reductases were detected in the same cytoplasm gluconobacter suboxydans. It notes that NADH-dependent appears inducible and labile in nature while the NADPH-dependent appears constitutive and stable. It also notes that the two DHARS were specific only to DHA reduction to glycerol.

The article reports on a study on the novel 3-dehydroquinate dehydrase (DQD) catalyzing extracellular formation of 3-dehydroshikimate by oxidative fermentation of Gluconobacter oxydans IFO 3244. The study showed that the same apparent molecular weights and same catalytic properties, but they were distinct from each other in subunit molecular mass.

The article discusses a study which investigated the energy metabolism and respiratory chain of Asaia bogorensis. A. bogorensis is a unique acetic acid bacterium with unusual properties including scanty acetic acid production and rapid growth. The found that A. bogorensis lacks quinoprotein alcohol dehydrogenase, but has sugar and sugar alcohol-oxidizing enzymes specific to the respiratory chain of Gluconobacter.

The article reports on results of a study of physiological roles of two membrane-bound dehydrogenases responsible for d-sorbitol oxidation in Gluconobacter frateurii. A description of the study design and method is presented. The study concluded that pyroloquinoline quinone-dependent glycerol dehydrogenase (PQQ-GLDH) connects efficiently to cytochrome bo3 terminal oxidase.

The article reports on the results of a study of the occurrence of a novel NADH dehydrogenase (NADH-dh), distinct from the old yellow enzyme, in gluconobacter strains A description of the experimental set-up and measurement methods is presented. The study concluded that the N-terminal amino acid sequence of NADPH-dh matched a putative oxidoreductase containing the old yellow enzyme-like FMN-binding domain.

The article describes the preparation of two enzymes, 5-keto D-gluconate (5KGA) reductase (5KGR) and 2-keto D-gluconate (2KGA) reductase (2KGR) for quantification of 5KGA and 2KGA. According to the authors, the gene for 5KGR was found in the genome of Gluconobacter oxydans 621H and was identified as GOX2187, and the gene for 2KGR was identified as GOX0417 from the N-terminal amino acid sequence of the partially purified enzyme. The overexpression of 5KGR and 2KGR in Escherichia coli was noted.

The article examines the purification and properties of NADP-dependent shikimate dehydrogenase (SKDH) from Gluconobacter oxydans IFO 3244 and its application to enzymatic shikimate production. It showed a single protein band on native-polyacrylamide gel electrophoresis accompanying activity when SKDH was purified from Gluconobacter oxydans IFO 3244. It required NADP exclusively and catalyzed only the shuttle reaction between shikimate and 3-dehydroshikimate.

The article presents a study on the high shikimate (SKA) production from quinate with two enzymatic systems of acetic acid bacteria. 3-Dehydroshikimate was formed with a yield of 57 to 77 percent from quinate thru 3-dehydroquinate by two successive enzyme reactions, quinoprotein quinate dehydrogenase and 3-dehydroquinate dehydratase, in the cytoplasmic membranes of acetic acid bacteria. A strategy for high SKA production was proposed based on the data presented.

The article discusses the study about the conversion of capsular polysaccharide (CPS) to extracellular polysaccharide (EPS) by galE deletion in acetobacter tropicalis. A clone of the galE gene from Acetobacter tropicalis was performed. Results show that the cloned gene does not produce CPS, but secreted an EPS, which is purified and having a unique characteristic from the original CPS.

The article discusses the results of a study which examined membrane-bound NAD(P)-independent formaldehyde-oxidizing enzyme from Acetobacter sp. SKU 14. The enzyme was solubilized from the membrane fraction of glycerol-grown cells and was purified to homogeneity through column chromatographies. The purified enzyme was characterized as a quinoprotein alcohol dehydrogenase.

Examines the molecular properties of membrane-bound FAD-containing D-sorbitol dehydrogenase (SLDH) from thermotolerant Gluconobacter frateurii, an acetic acid bacteria. Industrial application of Gluconobacter strains; Role of SLDH in L-sorbose fermentation; Method used for the purification of FAD-SLDH from Gluconobacter frateurii.

Cites a study presenting the purification of type II NADH dehydrogenase of Corynebacterium glutamicum (NDH-2) from an ndh over-producing strain. Enrichment of NDH-2 by 6-fold higher specific activity of NADH after purification; Ability of the purified enzyme to catalyze electron transfer from NADH and NADPH to oxygen as well as various artificial quinone analogs; Presentation of C. glutamicum NDH-2 as a source of the reactive oxygen species, superoxide and hydrogen peroxide, concominant with NADH and NADPH oxidation.

Discusses 3-dehydroquinate production from quinate by oxidative fermentation with Gluconobacter strains of acetic acid bacteria and the further conversion of 3-dehydroquinate to the intermediates in the shikimate pathway. Quinate oxidation by acetic acid bacteria; Quinate oxidation by immobilized cells of acetic acid bacteria; Chromatographic detection of oxidative products.

Discusses the purification and characterization of membrane-bound quinoprotein quinate dehydrogenase (QDH). Occurrence of QDH in aerobic bacteria; Titration of apo-QDH with PQQ; Properties of purified QDH; Identification of quinate oxidation product by the membrane-bound QDH.

Investigates the molecular cloning of quinohemoprotein alcohol dehydrogenase (ADH IIB) from Pseudomonas putida HK5. Identification of a gene diverntly transcribed against qbdBA with NAD-dependent adelhyde dehydrogenase.

Describes the purification and characterization of two NAD-dependent alcohol dehydrogenase (ADH) from the soluble fraction of Acetobacter pasteurianus CN5-2. Homology of the ADH I and ADH II to the long-chain and short-chain ADH families; Difference in their kinetics on ethanol, acetaldehyde, NAD and NADH.