Melibiose

About: Melibiose is a research topic. Over the lifetime, 1002 publications have been published within this topic receiving 27300 citations. The topic is also known as: Melibiose.

Raffinose metabolism and a novel mode of sucrose synthesis in corynebacterium murisepticum

Abstract: In C. murisepticum, a constitutive extracellular invertase hydrolyzes raffinose to melibiose and fructose. During growth on raffinose plus glucose, an unexpected appearance of sucrose was discovered in the growth medium. The enzyme preparation from raffinose-grown culture supernatant could synthesize in vitro, sucrose, and difructose from raffinose plus glucose or difructose from raffinose alone. The results thus bring to light a novel attribute of the extracellular invertase, of catalyzing the transfer of the fructose moiety of raffinose to glucose and fructose, thereby achieving the synthesis of sucrose, and difructose, respectively.

Detection of gentiobiose and sophorose in cultures of certain micro-organisms growing in defined glucose-containing media.

Abstract: THE ability of cellulose-forming species of Acetobacter to produce from glucose a mixture of melibiose, cellobiose, cellotriose, cellotetraose and fructose, together with higher oligosaccharides some of which yield fructose on hydrolysis, has been reported in recent communications1–3. We have now examined the behaviour, in comparable conditions, of Acetobacter aceti N.C.I.B. 8554, Acetobacter rancens N.C.I.B. 7214, Acetobacter acidum-mucosum N.C.I.B. 8133, and Acetobacter acetosum var. nairobiense N.C.I.B. 7212, none of which produces cellulose. A. aceti was grown in a medium containing (gm./l.): (NH4)2SO4, 3; MgSO4.7H2O, 2; KH2PO4, 3; glucose, 30. The same ingredients with addition (gm./l.) of: DL-alanine, 0.1; asparagine, 0.1; calcium D-pantothenate, 0.002; riboflavin, 0.002 and biotin, 0.0003, were employed to make up the medium for the three other species. These media were dispensed in volumes of 200 ml. in sixteen Glaxo flasks, four flasks for each species. After inoculation and incubation for 10 days at 28° C. the contents of each set of four flasks were Seitz-filtered and concentrated to about 50 ml. in presence of a little barium carbonate in vacuo at 35°. Each concentrate was filtered and treated in the following manner in all four cases. It was added to a column (4.5 cm. diameter) filled with a charcoal–‘Celite’ (50 : 50, w/w) mixture. The column was eluted with water (5 l.) and then with aqueous ethanol solutions containing, respectively, 5, 15, 20 and 35 per cent (v/v) of ethanol. The aqueous ethanolic eluates were combined (4 l.), concentrated under low pressure at 35° C. to 500 ml. and treated successively with ‘Zeo-Karb 225’ (H+ form) and ‘De-Acidite E’ (OH− form).

A galactosyltransferase from Erwinia amylovora and its possible role in biosynthesis of polysaccharide in infected tissues

Abstract: A galactosyltransferase (UDP galactose: D-glucose 4-β-galactosyl transferase; E.C. 2.4.l.22) was partially purified by 30 to 75% ammonium sulfate fractionation, QAE-Sephadex and Sephadex G 150 column chromatography from a soluble fraction (40 000 g) of sonicated bacterial cells of Erwinia amylovora (ATCC 19381). The enzyme activity was assayed in a 0·l ml aqueous reaction mixture containing 5 μmol of Tris-HCI buffer, pH 7·2, 4 μmol of manganese chloride, 47 pmol of UDP-(1'C) galactose (2·7 x 104 dpm), 2 μmol of acceptor and enzyme preparation. This enzyme transferred galactose from UDP-galactose to glucose in the presence of α-lactalbumin and to N-acetylglucosamine and amylovorin primer in the absence of α-lactalbumin. n -Acetylgalactosamine, maltose and melibiose were not galactose acceptors. The specificity of the enzyme suggests that the galactosyltransferase may play an important role in the production of amylovorin, a galactose-rich polysaccharide, found in the exudates on the surface of apple and pear tissues infected by E. amylovora.

Characteristics and Fatty Acid Composition of Yeast Isolated from the Intestines of Rainbow Trout

Abstract: A species of yeast was isolated from the intestines of rainbow trout Onco rhynchus mykiss fed with pelleted diets in two different aquaculture stations. The yeast isolates were found to multiply by budding, not to form spore and any pigment and identified as Candida sp. The yeast isolates fermented glucose, galactose, sucrose, fructose, inulin and trehalose but not lactose, mannitol, malt ose, inositol, melibiose, cellobiose and starch. The isolates grew poorly on Z-AII agar without glucose, whereas they grew very well on Z-AII agar with glucose (ZAG agar). The representative strain Y91-01 grew in a temperature range of 13 to 34X3, in a pH range of 2 to 9, and in a NaCl concentration range of 0 to 7%. Strain Y91-01 required biotin as incubated in glucose-(NH4)2S04 medium. The total lipids extracted from strain Y91-01 cells contained Ci6:i, Ci6:o, Cw:i and Ci8:o as major fatty acids.

[Identification and metabolism characterization of a Clostridium lituseburense strain isolated from high-altitude soil].

Abstract: Objective We studied the physiological, biochemical properties and metabolism of Clostridium lituseburense P4-1 from soil in Namucuo. Methods We adopted Hungate anaerobic technique to get Strain P4-1 from soil in Namucuo. Through physiological, biochemical and phylogenetic analysis, we identified the strain P4-1. Results Cells were Gram-positive and spore-forming. It grew between 13 and 40 degrees C (optimum at 37 degrees C), between pH value 5.0 and 10.O (optimum at 7.5-8.0), and with the presence of NaCl between 0%-5%. Strain P4-1 could metabolize many carbon sources including glucose, melibiose and mannitol. Metabolites of glucose were acetate, butyrate, propionate, CO2, and little H2. Based on 16S rDNA studies, strain P4-1 was most close to Clostridium lituseburense DSM 797 (M59107) with 98.7% similarity. Strain P4-1 could degrade p-toluene sulfonate. Conclusion Strain P4-1 tolerated low temperature, salt and could degrade p-toluene sulfonate. Its metabolites produced by fermentation of glucose could improve the soil micro-environment. It was significant for strain P4-1 to be utilized in the wastewater treatment.