Showing papers on "Arabitol published in 1993"

Conditions of formation, purification, and characterization of an alpha-galactosidase of Trichoderma reesei RUT C-30.

Abstract: Trichoderma reesei RUT C-30 formed an extracellular alpha-galactosidase when it was grown in a batch culture containing lactose or locust bean gum as a carbon source. Short-chain alpha-galactosides (melibiose, raffinose, stachyose), as well as the monosaccharides galactose, dulcitol, arabinose, and arabitol, also induced alpha-galactosidase activity both when they were used as carbon sources (at a concentration of 1%) in batch cultures and in resting mycelia (at concentrations in the millimolar range). The addition of 50 mM glucose did not affect the induction of alpha-galactosidase formation by galactose. alpha-Galactosidase from T. reesei RUT C-30 was purified to homogeneity from culture fluids of galactose-induced mycelia. The active enzyme was a 50 +/- 3-kDa, nonglycosylated monomer which had an isoelectric point of 5.2. It was active against several alpha-galactosides (p-nitrophenyl-alpha-D-galactoside, melibiose, raffinose, and stachyose) and galactomannan (locust bean gum) and was inhibited by the product galactose. It released galactose from locust bean gum and exhibited synergism with T. reesei beta-mannanase. Its activity was optimal at pH 4, and it displayed broad pH stability (pH 4 to 8). Its temperature stability was moderate (60 min at 50 degrees C resulted in recovery of 70% of activity), and its highest level of activity occurred at 60 degrees C. Its action on galactomannan was increased by the presence of beta-mannanase. Images

The water relations of growth and polyhydroxy alcohol production by ascomycetous yeasts

Abstract: Summary: The response of 31 ascomycetous yeasts to a reduction in water activity (aW) adjusted with D-glucose or NaCl was investigated. The growth of most yeasts was more tolerant to glucose than to NaCl at equivalent aW. Zygosaccharomyces rouxii was the most osmotolerant yeast examined. Natural abundance 13C-NMR spectroscopy and HPLC analyses of eight yeasts indicated that glycerol and arabitol or mannitol were accumulated intracellularly in response to aW. reduction. Pichia sorbitophila, Candida cacaoi, Candida magnoliae and Zygosaccharomyces bisporus responded to reduced aW by a decrease in specific growth rate and cell volume, and an accumulation of glycerol. The other polyol accumulated did not increase in concentration with aW reduction to the same degree as glycerol. A polyol concentration ratio (intra/extracellular) as high as 800-fold was attained across the membrane. Greater amounts of polyols were produced at equivalent aW values when adjusted with glucose than with NaCl. The ability to accumulate high concentrations of polyols appears to be the most important criterion in determining osmotolerance.

Combination of sugars with animo acids and other drugs

Abstract: A material which has the ability to effect it's passage, at least in part, and the ability to transport other materials through the blood-brain barrier which includes any one or more pure sugars or pure amino sugars from the group consisting of meso erythritol, zylitol, D(+) galactose, D(+) lactose, D(+) xylose, dulcitol, myo-insoitol, L(-) fructose, D(-) mannitol, sorbitol, D(+) glucose, D(+) arabinose, D(-) arabinose, celloboise, D(+) maltose, D(+) raffinose, L(+)rhamnose, D(+) melibiose, D(-) ribose, adonitol, D(+) arabitol, L(-) arabitol, D(+) fucose, L(-) fucose, D(-) lyxose, L(+) lyxose, L(-) lyxose, D(+) glucosamine, D mannosamine, and D galactosamine; and any one or more amino acids from the group consisting of arginine, asparagine, aspartic acid, cysteine, glutamic acid, glycine, histidine, leucine, methionine, phenylalanine, proline, serine, threonine, glutamine, lysine, tryptophan, tyrosine, valine, and taurine. For use in the research or treatment of a subject that material is combined with one or more of the substances beta carotene, xanthophyll, lecithin, calcium, somatostatin, vasopressin, endorphin, enkephalin, acetyl-L-carnitine, GABA, dynorphin, L-tryptophan, choline, thiamine, pyridoxine, niacin, L-arginine, hydroxyproline, NGF, methionine, cystine, potassium, phosphorus, chlorine, sodium, vitamins A, B, C, D and E, tricalcium phosphate, omega 3 and omega 6 both of which are high linolenic acids, oats, rice, apple fiber, acidophilus, and selenium.

D-arabitol metabolism in Candida albicans: studies of the biosynthetic pathway and the gene that encodes NAD-dependent D-arabitol dehydrogenase.

Abstract: Candida albicans produces large amounts of the pentitol D-arabitol in culture and in infected mammalian hosts, but the functional and pathogenic significance of D-arabitol in C. albicans is not known. In this study, we sought to elucidate the pathway by which C. albicans synthesizes D-arabitol and to identify and characterize key enzymes in this pathway. C. albicans B311 produced D-[14C-1]arabitol from [14C-2]glucose; this finding implies on structural grounds that D-ribulose-5-PO4 from the pentose pathway is the major metabolic precursor of D-arabitol. NAD- or NADP-dependent pentitol dehydrogenases catalyze the final steps in D-arabitol biosynthesis in other fungi; therefore, lysates of C. albicans B311 were tested for enzymes of this class and were found to contain a previously unknown NAD-dependent D-arabitol dehydrogenase (ArDH). The ArDH structural gene was cloned by constructing a new D-arabitol utilization pathway in Escherichia coli. The C. albicans ArDH gene expressed in E. coli and Saccharomyces cerevisiae an enzyme that catalyzes the reaction D-arabitol + NAD D-ribulose + NADH; this gene was present as a single copy per haploid genome, and its deduced peptide sequence was homologous with sequences of several members of the short-chain dehydrogenase family of enzymes. These results suggest that (i) C. albicans synthesizes D-arabitol by dephosphorylating and reducing the pentose pathway intermediate D-ribulose-5-PO4 and (ii) ArDH catalyzes the final step in this pathway.

Intracellular polyol accumulation by yeastlike fungi of the genera Geotrichum and Endomyces in response to water stress (NaCl)

Abstract: The growth and intracellular accumulation of polyhydroxy alcohols (polyols) were studied in 10 yeastlike fungi of the genera Geotrichum and Endomyces in media with and without the addition of NaCl. The specific growth rate of all strains decreased when the NaCl concentration in the medium was higher than 0.25 M, and no growth occurred at concentrations higher than 1.50 M. High-performance liquid chromatography showed that mannitol was the main polyol accumulated during the late exponential and stationary phases of growth in media without added NaCl. In the presence of 0.75 or 1.0 M NaCl these organisms, with the exception of Geotrichum penicillatum IGC 3460, accumulated high levels of arabinitol (arabitol) as a compatible solute; mannitol was detected in trace amounts only in the late stationary phase of some strains. Geotrichum penicillatum IGC 3460, however, accumulated mannitol instead of arabinitol in response to an increase of NaCl in the growth medium. In this organism, the substitution of arabinito...

Polyol concentrations in Aspergillus repens grown under salt stress.

Abstract: Na+, K+ and the ratio of Na+/K+ were higher in cells of the halotolerant Aspergillus repens grown with 2 M NaCl than without NaCl. The osmolytes, proline, glycerol, betaine and glutamate, did not affect the Na+/K+ ratio, nor the polyol content of cells under any conditions. The concentrations of polyols, consisting of glycerol, arabitol, erythritol and mannitol, changed markedly during growth, indicating that they have a crucial role in osmotic adaptation.

Production of saccharide compound

Abstract: PURPOSE:To obtain a saccharified compound having a dental carries preventing effect and a sweetness in high purity from glucose-1-phosphoric acid and sugar alcohol by using sucrose phosphorylase without requiring any complicated isolation and purification treatment. CONSTITUTION:Glucose-1-phosphoric acid or sucrose is made to react with a sugar alcohol (e.g. xylitol or arabitol) using sucrose phosphorylase to provide the objective saccharide compound in which glucose and sugar alcohol are bound. The reaction is preferably carried out at 35-45 deg.C and pH6-7 for 8-15hr. Furthermore, as the sucrose phosphorylase, e.g. enzyme derived from Leuconostoc mesenteroides is used.

Method of xylitol producing

Abstract: FIELD: genetic engineering, microbiological industry, biotechnology. SUBSTANCE: yeasts or fungi producing arabitol are transformed with DNA encoding D-arabitol dehydrogenase forming D-xylose and DNA encoding xylitol dehydrogenase. Then transformed yeasts or fungi are cultured under conditions providing the synthesis of xylitol and xylitol is isolated. Yeasts are taken among Zygosaccharomyces rouxii, Candida polymorpha, Torulopsis candida, Pichia farinosa, Torulaspora hansenii. Fungi are taken among Dendryphiella salina and Schizophyllum commune. Method ensures to convert easily available carbon sources, for example, D-glucose to xylitol. EFFECT: improved method of producing. 21 cl, 13 dwg, 7 tbl, 15 ex