Interaction of Organogermanium Compounds with Saccharides in Aqueous Solutions: Promotion of Aldose-to-ketose Isomerization and Its Molecular Mechanism.

This review discusses sugar isomerization with organogermanium compounds. Organogermanium compounds markedly increase the aldose-ketose (glucose-fructose or lactose-lactulose) isomerization ratio, double the initial reaction rate, and significantly reduce the base-catalyzed degradation of sugars. H-nuclear magnetic resonance analysis reveals that the affinity of organogermanium compounds with a 3-(trihydroxygermyl)propanoic acid (THGP) structure toward ketoses is 20-40 times stronger than that toward aldoses; thus, such organogermanium compounds form complexes more readily with ketoses than with aldoses.

An Organogermanium Compound Enhances the Initial Reaction Rate of Alkaline Isomerization of an Aldose into a Ketose through Enediol Complex Formation.

We previously demonstrated that the organogermanium compound 3-(trihydroxygermyl)propanoic acid (THGP) enhances the enzymatic and alkaline isomerization of an aldose to a ketose through -diol complex formation by multiple mechanisms. Its higher affinity for the ketose than the aldose protects the ketose complex from alkaline decomposition. Furthermore, it has been reported that the aldose-ketose alkaline isomerization pathway includes 1,2-enediol.

Erythritol: Another C4 Platform Chemical in Biomass Refinery.

The potential of erythritol as a platform chemical in biomass refinery is discussed in terms of erythritol production and utilization. Regarding erythritol production, fermentation of sugar or starch has been already commercialized. The shift of the carbon source from glucose to inexpensive inedible waste glycerol is being investigated, which will decrease the price of erythritol.

Efficient Continuous Production of Lactulose Syrup by Alkaline Isomerization Using an Organogermanium Compound.

Lactulose, a keto-type disaccharide widely used in pharmaceuticals and functional foods, is produced by the isomerization of lactose. The organogermanium compound poly--[(2-carboxyethyl) germasesquioxane] (Ge-132) is an effective reaction promoter for the conversion of lactose to lactulose because of its high affinity to ketoses. Herein, an effective method for the continuous production of lactulose syrup was developed using Ge-132 through the alkaline isomerization of lactose in a bench-scale plant.

Aspergillus luchuensis fatty acid oxygenase ppoC is necessary for 1-octen-3-ol biosynthesis in rice koji.

Awamori is a distilled spirit produced in Okinawa Prefecture, in southern Japan. Awamori contains the volatile organic compound 1-octen-3-ol, an important flavor component. Here, using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GCMS), we demonstrate that the black koji mold Aspergillus luchuensis produces 1-octen-3-ol in rice koji.

Generation of Mutant with Enhanced Xylanase Activity by Using Disparity Mutagenesis.

In the current study, we attempted to enhance the xylanase activity of ATCC66589 by using disparity mutagenesis, wherein a plasmid harboring proofreading-impaired DNA polymerase δ was inserted. Following selection on xylan-rich media and successive plasmid curing, a mutant showing conidiospores strikingly different from those of the parent strain, with many small humped-surface spheres, was generated. Xylanase and β-xylosidase activities of the mutant XM1, cultivated in xylan medium, were 15.

Efficient Alkaline Isomerization of Lactose to Lactulose in the Presence of an Organogermanium Compound.

Lactulose, a disaccharide widely used in pharmaceuticals and functional foods, is produced by lactose isomerization. Lactose and lactulose have an aldose-ketose relationship. Less than 25 % conversion of lactose into lactulose is achieved using the Lobry de Bruyn-Alberda van Ekenstein transformation with heating, whereas the conversion is increased to 80 % by the addition of an approximately equimolar concentration of the organogermanium compound 3-(trihydroxygermyl)propanoic acid (THGP) to the reaction mixture.

Production of rice straw hydrolysis enzymes by the fungi Trichoderma reesei and Humicola insolens using rice straw as a carbon source.

Rice straw was evaluated as a carbon source for the fungi, Trichoderma reesei and Humicola insolens, to produce enzymes for rice straw hydrolysis. The enzyme activity of T. reesei and H.

Complementary function of two transketolase isoforms from Moniliella megachiliensis in relation to stress response.

Two transketolase isogenes, MmTKL1 and MmTKL2, isolated from Moniliella megachiliensis were investigated for their roles in stress response and erythritol biosynthesis. The encoded proteins were highly homologous in amino acid sequence and domain structure. Two stress response elements (STREs) were found upstream of MmTKL1, while no STRE was found upstream of MmTKL2.

The relationship between the violet pigment PP-V production and intracellular ammonium level in Penicillium purpurogenum.

Penicillium purpurogenum is the fungus that produces an azaphilone pigment. However, details about the pigment biosynthesis pathway are unknown. The violet pigment PP-V is the one of the main pigments biosynthesized by this fungus.

Efficient Conversion of D-Glucose to D-Fructose in the Presence of Organogermanium Compounds.

D-Glucose and D-fructose are isomers of commonly consumed monosaccharides. The ratio of conversion of D-glucose to D-fructose by glucose isomerase (xylose isomerase) is not more than 50 %. However, addition of an equimolar ratio of the organogermanium compound poly--[(2-carboxyethyl)germasesquioxane] (Ge-132) or its derivative increases the conversion ratio to 80 %.

Two glycerol 3-phosphate dehydrogenase isogenes from Candida versatilis SN-18 play an important role in glycerol biosynthesis under osmotic stress.

Two isogenes of glycerol 3-phosphate dehydrogenase (GPD) from Candida versatilis SN-18 were cloned and sequenced. These intronless genes (Cagpd1 and Cagpd2) were both predicted to encode a 378 amino acid polypeptide, and the deduced amino acid sequences mutually showed 76% identity. Interestingly, Cagpd1 and Cagpd2 were located tandemly in a locus of genomic DNA within a 262 bp interval.

PP-O and PP-V, Monascus pigment homologues, production, and phylogenetic analysis in Penicillium purpurogenum.

The production of pigments as secondary metabolites by microbes is known to vary by species and by physiological conditions within a single strain. The fungus strain Penicillium purpurogenum IAM15392 has been found to produce violet pigment (PP-V) and orange pigment (PP-O),Monascus azaphilone pigment homologues, when grown under specific culture conditions. In this study, we analysed PP-V and PP-O production capability in seven strains of P.

NP24 induces apoptosis dependent on caspase-like activity in Saccharomyces cerevisiae.

Tomato NP24 is a homolog of osmotin, a PR-5 protein from tobacco that can initiate apoptosis in yeast via PHO36 in the plasma membrane. We cloned and sequenced NP24 from tomato cv. Momotaro.

Generation of a glucose de-repressed mutant of Trichoderma reesei using disparity mutagenesis.

We obtained a novel glucose de-repressed mutant of Trichoderma reesei using disparity mutagenesis. A plasmid containing DNA polymerase δ lacking proofreading activity, and AMAI, an autonomously replicating sequence was introduced into T. reesei ATCC66589.

Metabolic correlation between polyol and energy-storing carbohydrate under osmotic and oxidative stress condition in Moniliella megachiliensis.

Moniliella megachiliensis, the osmo-tolerant basidiomycetous yeast was found to accumulate intracellularly energy-storing carbohydrates (trehalose and glycogen) along with polyols (glycerol and erythritol) up to stationary growth phase. In trehalose-loaded cell, osmotic-stress resulted in the rapid generation of glycerol, and oxidative stress with menadione resulted in the rapid generation of erythritol. Under either of these conditions, the levels of the energy-storing carbohydrates were depleted, while little glucose uptake was observed.

Construction of transformation system in Penicillium purpurogenum.

Penicillium purpurogenum attracts attention in the food industry and biomass degradation. We expressed green fluorescent protein (GFP) with pBPE, a novel vector, and constructed a transformation system for P. purpurogenum.

Two transaldolase isogenes from Moniliella megachiliensis behave in a different way depending on the stress class.

We cloned and sequenced two transaldolase genes from Moniliella megachiliensis, a microorganism known to produce a significant amount of erythritol under hyper-osmotic stress. The amino acid sequences encoded by these two genes (MmTAL1, MmTAL2) showed 72% homology to each other. An AP-1 (ap response element) associated with oxidative stress was found in the promoter region of MmTAL1, while four STREs (stress response element) associated with osmotic stress were found in the promoter region of MmTAL2.

Tomato FRUITFULL homologs regulate fruit ripening via ethylene biosynthesis.

Certain MADS-box transcription factors play central roles in regulating fruit ripening. RIPENING INHIBITOR (RIN), a tomato MADS-domain protein, acts as a global regulator of ripening, affecting the climacteric rise of ethylene, pigmentation changes, and fruit softening. Previously, we showed that two MADS-domain proteins, the FRUITFULL homologs FUL1 and FUL2, form complexes with RIN.

Transcriptional regulation of fruit ripening by tomato FRUITFULL homologs and associated MADS box proteins.

The tomato (Solanum lycopersicum) MADS box FRUITFULL homologs FUL1 and FUL2 act as key ripening regulators and interact with the master regulator MADS box protein RIPENING INHIBITOR (RIN). Here, we report the large-scale identification of direct targets of FUL1 and FUL2 by transcriptome analysis of FUL1/FUL2 suppressed fruits and chromatin immunoprecipitation coupled with microarray analysis (ChIP-chip) targeting tomato gene promoters. The ChIP-chip and transcriptome analysis identified FUL1/FUL2 target genes that contain at least one genomic region bound by FUL1 or FUL2 (regions that occur mainly in their promoters) and exhibit FUL1/FUL2-dependent expression during ripening.

Evidence for the presence of lipid-free monomolecular apolipoprotein A-1 in plasma.

The first step in reverse cholesterol transport is a process by which lipid-free or lipid-poor apoA-1 removes cholesterol from cells through the action of ATP binding cassette transporter A1 at the plasma membrane. However the structure and composition of lipid-free or -poor apoA-1 in plasma remains obscure. We previously obtained a monoclonal antibody (MAb) that specifically recognizes apoA-1 in preβ1-HDL, the smallest apoA-1-containing particle in plasma, which we used to establish a preβ1-HDL ELISA.

Cell dispersion culture for the effective growth of Humicola insolens and efficient enzyme production.

We have developed a method for the effective growth of Humicola insolens conducive to efficient enzyme production using a medium containing glucose as a carbon source and extruded soybean meal (ExSBM) as a nitrogen source. Enzymes from Humicola sp. hold promise for biomass degradation, especially of lignocellulosic materials such as rice straw, wood chips, and corn stover.

Tomato FRUITFULL homologues act in fruit ripening via forming MADS-box transcription factor complexes with RIN.

The tomato MADS-box transcription factor RIN acts as a master regulator of fruit ripening. Here, we identified MADS-box proteins that interact with RIN; we also provide evidence that these proteins act in the regulation of fruit ripening. We conducted a yeast two-hybrid screen of a cDNA library from ripening fruit, for genes encoding proteins that bind to RIN.

Importance of the ammonia assimilation by Penicillium purpurogenum in amino derivative Monascus pigment, PP-V, production.

A fungal strain, Penicillium purpurogenum IAM 15392, produced the azaphilone Monascus pigment homolog when cultured in a medium composed of soluble starch, ammonium nitrate, yeast extract, and citrate buffer, pH 5.0. One of the typical features of violet pigment PP-V [(10Z)-12- carboxyl-monascorubramine] is that pyranoid oxygen is replaced with nitrogen.

Gene expression and function involved in polyol biosynthesis of Trichosporonoides megachiliensis under hyper-osmotic stress.

Among three erythritol reductase isogenes (er1, er2, and er3) in Trichosporonoides megachiliensis SN-124A, er1 and er2 each had one stress response element (STRE) approximately 2 kbp upstream of their respective initiator codon; in contrast, er3 had two STREs, 148 and 40 bp upstream from the initiator codon. Based on intracellular erythritol accumulation and gene expression profiles, er3 seemed to be highly responsive to stress than er1 or er2. Under hyper-osmotic conditions, intracellular glycerol production, increased significantly within 1.