Production & Characterization of a Unique Dextran from an Indigenous Leuconostoc mesenteroides CMG713

Abstract

On the basis of high enzyme activity a newly isolated strain of L. mesenteroides CMG713 was selected for dextran production. For maximum yield of dextran, effects of various parameters such as pH, temperature, sucrose concentration and incubation period were studied. L. mesenteroides CMG713 produced maximum dextran after 20 hours of incubation at 30°C with 15% sucrose at pH 7.0. The molecular mass distribution of dextran produced by this strain showed that its molecular mass was about 2.0 million Da. Dextran analysis by 13 C-NMR spectrometry showed no signals corresponding to any other linkages except α-(1→6) glycosidic linkage in the main chain, which has not been reported before. Physico-chemical properties of this unique dextran were also studied. These optimised conditions could be used for the commercial production of this unique high molecular weight dextran, which have significant industrial perspectives.

An alternative method for screening lactic acid bacteria for the production of exopolysaccharides with rapid confirmation

“…medium (CERNING et al, 1994;SARWAT et al, 2008), both of which require a great amount of medium and glassware. Table 1 shows the result of screening lactic acid bacteria isolated under different growing conditions.…”

Comparative influence of immobilization medium and mutation on EPS - production by L. Plantarum MK 02 isolated from fermented milk

“…Among them, the best known are L. casei, L. acidophilus, L.brevis, L. curvatus, L. delbrueckii, L. helveticus, L. rhamnosus, L plantarum and L. johnsonii (5). Dextran (synthesized by certain LAB such as Leuconostoc mesenteroides) was the first microbial polysaccharide to be commercially exploited and to receive authorization for use in foods (6).…”

Biosynthesis, Purification and Biotechnological Use of Exopolysaccharides Produced by Lactic Acid Bacteria

“…Lc. mesenteroides CMG713 produces the highest concentration of dextran after 20 hours of incubation at 30°C in the presence of 15% sucrose at pH 7.0, with an EPS yield of 6 g L -1 (Sarwat et al, 2008). Recently, Capek et al (2011) reported an exceptionally high production of this HoPS (50 g L -1 ) by Lc.…”

“…The depletion of the sucrose source would cause the arrest of the enzymatic reaction of the dextransucrases. It has been reported that high producers of dextran are primarily Leuconostoc, but many other strains of LAB are able to produce this bacterial polysaccharide (Sarwat et al, 2008). The importance of improving its production is related to the industrial applications in the food, pharmaceutical and chemical industries as adjuvant, emulsifier, carrier or stabilizer (Goulas et al, 2004).…”