Synthesis of methyl Alpha-D-Glucoolicosaccharides by Entrapped Dextransucrase from Leuconostoc mesenteroides B-1299

The synthesis of methyl alpha-D-glucooligosaccharides, using sucrose as glucosyl donor and methyl alpha-D-glucopyranoside as acceptor, was studied with dextransucrase from Leuconostoc mesenteroides NRRL B-1299. The enzyme was immobilized by entrapment in alginate. By NMR and mass spectrometry we identified three homologous series (S1-S3) of methyl alpha-D-glucooligosaccharides. Series S2 and S3 were characterized by the presence of alpha(1-2) linkages, in combination with alpha(1-6) bonds. Two parameters, sucrose to acceptor concentration ratio (S/A) and the total sugar concentration (TSC) determined the yield of methyl alpha-D-glucooligosaccharides. The maximum concentration achieved of the first acceptor product, methyl alpha-D-isomaltoside, was 65 mM using a S/A 1:4 and a TSC of 336 g l-1. When increasing temperature, a shift of selectivity towards compounds containing alpha(1-2) bonds was observed. The formation of leucrose as a side process was very significant (reaching values of 32 g l-1) at high sucrose concentrations.We are very grateful to Profs. P. Monsan and M. Remaud-Simeon (INSA, Toulouse) for providing us with dextransucrase. We thank Prof. A. Cortés (ICP, CSIC) for helpful comments. We thank Gobierno Vasco and Instituto Danone for research fellowships. This work was supported by the Spanish Education and Science Ministry (Project BIO2004-03773-C04-01).Peer reviewe

Synthesis of methyl Alpha-D-Glucoolicosaccharides by Entrapped Dextransucrase from Leuconostoc mesenteroides B-1299

The synthesis of methyl alpha-D-glucooligosaccharides, using sucrose as glucosyl donor and methyl alpha-D-glucopyranoside as acceptor, was studied with dextransucrase from Leuconostoc mesenteroides NRRL B-1299. The enzyme was immobilized by entrapment in alginate. By NMR and mass spectrometry we identified three homologous series (S1-S3) of methyl alpha-D-glucooligosaccharides. Series S2 and S3 were characterized by the presence of alpha(1-2) linkages, in combination with alpha(1-6) bonds. Two parameters, sucrose to acceptor concentration ratio (S/A) and the total sugar concentration (TSC) determined the yield of methyl alpha-D-glucooligosaccharides. The maximum concentration achieved of the first acceptor product, methyl alpha-D-isomaltoside, was 65 mM using a S/A 1:4 and a TSC of 336 g l-1. When increasing temperature, a shift of selectivity towards compounds containing alpha(1-2) bonds was observed. The formation of leucrose as a side process was very significant (reaching values of 32 g l-1) at high sucrose concentrations.We are very grateful to Profs. P. Monsan and M. Remaud-Simeon (INSA, Toulouse) for providing us with dextransucrase. We thank Prof. A. Cortés (ICP, CSIC) for helpful comments. We thank Gobierno Vasco and Instituto Danone for research fellowships. This work was supported by the Spanish Education and Science Ministry (Project BIO2004-03773-C04-01).Peer reviewe

Procedimiento para la inmovilización covalente de dextransacarasa sobre soportes acrílicos de distinta porosidad con grupos oxirano

Referencia OEPM: P200302264.-- Fecha de solicitud: 01/10/2003.-- Titular: Consejo Superior de Investigaciones Científicas (CSIC).Procedimiento para la inmovilización covalente de dextransacarasa sobre soportes acrílicos de distinta porosidad con grupos oxirano. Se describe un procedimiento para la inmovilización de la enzima dextransacarasa de Leuconostoc mesenteroides NRRL B-512F sobre soportes acrílicos de distinta porosidad que contienen grupos oxirano. La unión que se establece con la enzima es covalente. Para favorecer la unión al soporte, se lleva a cabo un tratamiento previo de la enzima con dextranasa, con el fin de eliminar parte del dextrano envolvente. Se han variado una serie de parámetros en el proceso de inmovilización, concretamente las propiedades texturales del soporte, su contenido en grupos epóxido y la relación en peso enzima/soporte. En el presente procedimiento se reivindica la utilización de polímeros acrílicos activados con grupos epóxido para obtener biocatalizadores inmovilizados de dextransacarasa con una actividad por unidad de volumen superior a la obtenida por métodos de atrapamiento.Peer reviewe

Beet sugar syrup and molasses as low-cost feedstock for the enzymatic production of fructo-oligosaccharides

Sugar syrup and molasses from beet processing containing 620 and 570 mg/ml sucrose, respectively, were assayed as low-cost and available substrates for the enzymatic synthesis of fructo-oligosaccharides (FOS). A commercial pectinase (Pectinex Ultra SP-L, from Aspergillus aculeatus) characterised by the presence of a transfructosylating activity, was used as biocatalyst. The FOS production increased when lowering the initial pH value of syrup (7.5) and molasses (8.9) to 5.5. Sugar syrup and molasses were diluted in order to reduce substrate viscosity; interestingly, the percentage of FOS with regards to total sugars remained almost constant, which indicated a high transferase to hydrolase ratio for this enzyme. Kinetics of FOS production was analysed. Using approx. 10 U transfructosylating activity per g sucrose, the FOS concentration reached a maximum of 388 mg/ml after 30 h using syrup and 235 mg/ml in 65 h with molasses. These values corresponded to approx. 56% and 49% (w/w), respectively, of the total amount of carbohydrates in the mixture. The enzyme was also covalently immobilised on an epoxy-activated polymethacrylate-based polymer (Sepabeads EC-EP5). We found that immobilised Pectinex Ultra SP-L can be efficiently applied to the synthesis of FOS using syrup and molasses as substrates.We are very grateful to Azucarera Ebro (Valladolid, Spain) for supplying beet sugar syrup and molasses. We thank Drs. Moreno Daminati and Paolo Caimi (Resindion S.R.L., Milan, Italy) for providing us Sepabeads EC polymers and for technical help. We are grateful to Ramiro Martínez (Novozymes A/S, Spain) for providing us with Pectinex Ultra SP-L.Peer reviewe

Nueva enzima para la obtención de oligosacáridos prebióticos

Filing Date: 2005-12-15.-- Priority Data: ES P 200402994 (2004-12-16).The invention relates to a method of producing industrially-viable prebiotic oligosaccharides using a novel enzyme of Xanthophyllomyces dendrorhous, which is characterised by having α-glucosidase activity. The invention also relates to a method of obtaining an enzymatic product with α-glucosidase activity and the substantially-pure enzyme with α-glucosidase activity. The enzymatic product and the enzyme offer the advantage of having a high performance spectrum and a high specific activity. Said prebiotic oligosaccharaides are used in food

Transformation of maltose into prebiotic isomaltooligosaccharides by a novel alpha-glucosidase from Xantophyllomyces dendrorhous

The transglycosylation activity of a novel alpha-glucosidase from the basidiomycetous yeast Xanthophyllomyces dendrorhous (formerly Phaffia rhodozyma) was studied using maltose as glucosyl donor. The enzyme synthesized oligosaccharides with alpha-(1-2), alpha-(1-4) and alpha-(1-6) bonds. Using 200 g/l maltose, the yield of oligosaccharides was 53.8 g/l, with prebiotic oligosaccharides containing at least one alpha-(1-6) linkage (panose, 6-O-alpha-glucosyl-maltotriose and 6-O-alpha-isomaltosyl-maltose) being the major products (47.1 g/l). The transglycosylatying yield was 3.6 times higher than the observed with the alpha-glucosidase from Saccharomyces cerevisiae (53.8 vs. 14.7 g/l). Moreover, when increasing the maltose concentration up to 525 g/l, the maximum production of tri- and tetrasaccharides reached 167.1 g/l, without altering the percentage of oligosaccharides in the mixture. Compared with other microbial alpha-glucosidases in which the main transglycosylation product is a disaccharide, the enzyme from X. dendrorhous yields a final product enriched in trisaccharides and tetrasaccharides.Projects BIO2004-03773-C04-01 and BIO2004-03773-C04-03 from Spanish Ministry of Education and Science, and a grant from Genoma España −the National Foundation for Promoting Genomics and Proteomics− supported this research. We thank CSIC and Universidad Autonoma de Madrid (UAM) for research fellowships. D.L. was supported by a Spanish FPU fellowship from the Spanish Ministry of Education and Science.Peer reviewe

Immobilisation of fructosyltransferase from Aspergillus aculeatus on epoxy-activated Sepabeads EC for the synthesis of fructo-oligosaccharides

9 pages, 7 figures.-- Printed version published Aug 1, 2005.The transfructosylating activity present in two commercial pectinase preparations (Pectinex Ultra SP-L, from Aspergillus aculeatus, and Rapidase TF, from Aspergillus niger) was studied. Pectinex Ultra SP-L, which has a high transferase/hydrolase ratio, was covalently immobilised on a polymethacrylate-based polymer (Sepabeads® EC) activated with epoxy groups. The influence of pore volume and average pore size on biocatalyst performance was studied for two of these carriers (Sepabeads EC-EP3 and EC-EP5). Several parameters that affect immobilisation such as buffer concentration, pH and amount (mg) of protein added per gram of support (varied over the range 30:1 to 200:1) were analysed. We found that Pectinex Ultra SP-L can be efficiently immobilised on these supports without adding any external salt or buffer. Using Sepabeads EC-EP5 –whose pore volume (1.67 cm3/g) and pore size (800 nm) are higher than those corresponding to Sepabeads EC-EP3– the activity towards sucrose reached 25.9 U/g biocatalyst. The immobilised fructosyltransferase was applied to the batch synthesis of fructo-oligosaccharides (FOS) using 630 g/l sucrose to shift activity towards transfructosylation in detriment of hydrolysis. The FOS concentration reached a maximum value of 387 g/l after 36 h (240 g/l 1-kestose, 144 g/l nystose and 3 g/l 1(F)-fructofuranosyl-nystose), which corresponds to 61.5% (w/w) of the total carbohydrates in the mixture. The features of these immobilised biocatalysts are very attractive for their application in batch and fixed-bed bioreactors.We thank Drs. Moreno Daminati and Paolo Caimi (Resindion) for providing us Sepabeads EC polymers and for technical help. We are grateful to Ramiro Martínez (Novozymes A/S, Spain) and Gemma Hernández (DSM, Spain) for enzyme samples. This research was supported by the Spanish CICYT (Project BIO2004-03773-C04-01). We thank the Spanish AECI, Gobierno Vasco and Instituto Danone for research fellowships.Peer reviewe

Production of Conjugated Linoleic and Conjugated α-Linolenic Acid in a Reconstituted Skim Milk-Based Medium by Bifidobacterial Strains Isolated from Human Breast Milk

This is an open access article distributed under the Creative Commons Attribution License.Eight bifidobacterial strains isolated from human breast milk have been tested for their abilities to convert linoleic acid (LA) and α-linolenic acid (LNA) to conjugated linoleic acid (CLA) and conjugated α-linolenic acid (CLNA), respectively. These bioactive lipids display important properties that may contribute to the maintenance and improvement human health. Three selected Bifidobacterium breve strains produced CLA from LA and CLNA from LNA in MRS (160-170 and 210-230 g mL-1, resp.) and, also, in reconstituted skim milk (75-95 and 210-244 g mL-1, resp.). These bifidobacterial strains were also able to simultaneously produce both CLA (90-105 g mL -1) and CLNA (290-320 g mL-1) in reconstituted skim milk. Globally, our findings suggest that these bifidobacterial strains are potential candidates for the design of new fermented dairy products naturally containing very high concentrations of these bioactive lipids. To our knowledge, this is the first study describing CLNA production and coproduction of CLA and CLNA by Bifidobacterium breve strains isolated from human milk in reconstituted skim milk. © 2014 María Antonia Villar-Tajadura et al.This work was supported by AGL2011-26713, CYTED-IBEROFUN, CSD2007-00063 (FUN-C-FOOD), AGL2009-13361-C02-02, ALIBIRD P2009/AGR-1469, and AGL2010-15420 projects.Peer Reviewe