Characterization of dextransucrases fromLeuconostoc mesenteroides NRRL B-1299

Some Aspects of Carbohydrate Metabolism and Production of Glycosyltransferases from Mutant StrainLeuconostoc MesenteroidesM2860

“…The highest growth rate was limited after pH 5.0, which led to inactivation of the synthesized GTFs from M2860. It is known that in a pH below 5.0, the metabolitic processes of Leuconostoc mesenteroides are direct to compensatory process of glucan synthesis when sucrose concentration is high or to reduction of fructose by the mannitol dehydrogenase into mannitol at low sucrose concentration (3,17,6,10,15). The profiles of the fermentation process after cultivation of M2860 in media with sucrose and glucose as a carbon source respectively, showed that the enzymes were secreted into the culture broth during growth.…”

“…at 30C in 20 mM sodium acetate buffer, pH 5.4, with 100 g of sucrose per liter, 0.05 g of CaCl 2 per liter, and 1 g of NaN 3 per liter. It was ascertained that the reducing sugar measured by DNS assay was due to glucosyltransferase and not to levansucrase, inveratase, or sucrose phosphorylase activity as described by Dols, et al (3,4). Glucose concentration was measured enzymatically by glucose oxidase, using a Beckman Glucose Analyzer 2.…”

Optimization of Exopolysaccharide Overproduction byLactobacillus confususin Solid State Fermentation under High Salinity Stress

“…26) In the case of Leuconostoc mesenteroides NRRL B-1299, sucrose concentrations, above 5 g/L in the medium induced dextran production, and did not support growth and acid formation, and the production of dextransucrase was directly related to the growth of the strain NRRL B-1299. 27) But in the case of Lactobacillus casei 23) and Lactobacillus LB 121, 1,25) an excess of carbon and a shortage of nitrogen resulted in a high EPS yield with low biomass production. These results agree with our as to the production of EPS under high salt concentrations.…”

Characterization of Glucansucrases and Fructansucrases Produced by Wild StrainsLeuconostoc MesenteroidesURE13 andLeuconostoc MesenteroidesLM17 Grown on Glucose or Fructose Medium as a Sole Carbon Source

“…According to Monsan et al (27), small differences in the molecular mass could be observed due to variations in the electrophoretic conditions, to proteolytic degradation, or to dextran contamination of the protein preparation. Dols et al (10) demonstrated that L. mesenteroides nRRl B1299 produced two similar GS (molecular mass of 183 kDa and 186 kDa) when cultivated in fructose medium. Smith and Zahnley (44) showed that eight strains of L. mesenteroides produced low but detectable GS when glucose, maltose or melibiose replaced sucrose as the growth substrate.…”

“…Several mutant strains of L. mesenteroides (nRRl B-1355, nRRl B-742 and nRRl B-512FMc) have been described to produce glucansucrase activity in a medium with glucose as a carbon source (3,19,20,21). SDS-PAGe analysis of enzyme preparations showed active bands of molecular masses 173 kDa, 184 kDa, and 240 kDa in a constitutive mutant of L. mesenteroides (nRRl B-1299) cultivated in glucose medium (10).…”