Showing papers on "Arabitol published in 1999"

Production of xylitol by Candida peltata

Abstract: NRRL Y-6888 to ferment xylose to xylitol was evaluated under different fermentation conditions such as pH, temperature, aeration, substrate concentration and in the presence of glucose, arabinose, ethanol, methanol and organic acids. Maximum xylitol yield of 0.56 g g−1 xylose was obtained when the yeast was cultivated at pH 6.0, 28°C and 200 rpm on 50 g L−1 xylose. The yeast produced ethanol (0.41 g g−1 in 40 h) from glucose (50 g L−1) and arabitol (0.55 g g−1 in 87 h) from arabinose (50 g L−1). It preferentially utilized glucose > xylose > arabinose from mixed substrates. Glucose (10 g L−1), ethanol (7.5 g L−1) and acetate (5 g L−1) inhibited xylitol production by 61, 84 and 68%, respectively. Arabinose (10 g L−1) had no inhibitory effect on xylitol production.

Process for the separation of sugars

Abstract: Improved separations of xylose, mannose, galactose, arabinose, glucose, xylitol, arabitol, sorbitol, galactitol, or mannitol (and other monosaccharides and sugar alcohols) from other sugars and sugar alcohols may be achieved by chromatography over hydroxyl-form anion exchange surfaces prepared from anion exchange resins at relatively low hydroxyl concentrations. When a strong base anion exchange resin, such as a chloride-form strong base anion exchange resin, is conditioned with a low concentration of hydroxyl (for example, an NaOH solution with a concentration between 0.1 and 1000 nM, most preferably between 1 and 10 mM), the conditioned resin separates a number of sugars and sugar alcohols from one another, while still allowing ready desorption from the resin.

Overexpression of cyclodextrin glycosyltransferase gene from Brevibacillus brevis in Escherichia coli by control of temperature and mannitol concentration

Abstract: Expression of Brevibacillus brevis CD162 cyclodextrin glycosyltransferase (CGTase) gene using pET22b(+) vector in Escherichia coli BL21(DE3) resulted in the formation of inactive inclusion bodies under the usual induction conditions. However, by lowering the induction temperature to 30 °C and/or adding 0.5 M mannitol as an osmolyte, the formation of insoluble aggregates was prevented and about a 34-fold increase (8.51 U ml−1) in biologically active soluble form was achieved after 6 h induction. The active CGTase enzyme was estimated to comprise as much as 24% of the total soluble proteins. In addition, other polyols such as glycerol, erythritol, xylitol, sorbitol, and arabitol showed similar effects with mannitol on the production of active CGTase enzyme.

Characterisation of osmotolerant hybrids obtained by fusion between protoplasts of Saccharomyces cerevisiae and heat treated protoplasts of Torulaspora delbrueckii

Abstract: Saccharomyces cerevisiae was fused with heat-treated protoplasts of an osmotolerant yeast, Torulaspora delbrueckii, to obtain hybrids having increased tolerance to increased glucose concentrations (up to 700 g l−1). The production of glycerol and arabitol by the hybrids was within the range of those of the parental strains, but the production of ethanol was higher.

Admixtures for mineral binders based on (oxidised) sugar and hydrogenated sugar, admixture-containing mineral binders, and a process for the preparation thereof

Abstract: The invention relates to a novel admixture for mineral binders, composed of a composition containing at the same time a sugar or an oxidized sugar and a hydrogenated sugar The oxidized sugar may consist, in particular, of gluconic acid or one of its salts or an oxidized starch hydrolysate The hydrogenated sugar may consist in particular of maltitol, sorbitol, mannitol, xylitol, arabitol, or a hydrogenated starch hydrolysate containing at least 40% by weight of maltitol Within the admixture, this composition may be combined with conventional admixtures such as phosphates, borates, or amines The combination of a sugar or an oxidized sugar and a hydrogenated sugar within this composition makes it possible to obtain synergistic effects, particularly in terms of plasticity and mechanical properties of the mineral binders The admixtures claimed may be used equally well for admixing with cements, raw materials for cements as for admixing with mortars, slurries and concretes They may also be used in other sectors such as, for example, the plaster industry, particularly as complexing agents or hydration or dehydration controllers

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