Process development for the production of prebiotic galacto‐oligosaccharides from lactose using β‐galactosidase fromLactobacillussp.

Abstract

Galacto-oligosaccharides (GOS) are formed from lactose in discontinuous mode of conversion using beta-galactosidase from Lactobacillus sp. (beta-gal). The discontinuous process was optimized for technical application with regard to GOS yield, enzyme preparation, reaction temperature and substrate source. It proved to be advantageous to directly apply the crude cell-free enzyme extract for the conversion, since similar GOS yields and composition were obtained as when using the pure enzyme preparation, but expensive purification could be avoided. Reaction temperature was lowered to 17 degrees C to limit microbial contamination when using technical substrates. Thereby GOS yield decreased from 30% to 28% of total sugars and enzyme demand increased 2.7-fold. Whey permeate was compared to buffered lactose solution as a substrate source. The initial reaction rate was found to be 1.8 times higher for the whey permeate substrate; however, GOS yield was slightly lower (approximately 25% of total sugar at 17 degrees C) mainly due to smaller amounts of allolactose[beta-D-Galp-(1-->6)-D-Glc] and the trisaccharide beta-D-Galp-(1-->6)-D-Lac formed.

Galactooligosaccharide Production from Pantoea anthophila Strains Isolated from “Tejuino”, a Mexican Traditional Fermented Beverage

“…Based on the detailed analysis of the carbohydrate mixture profile, the permeabilized cells of P. anthophila strains display a high preference for the formation of galactosyl β(1 → 6) and β(1 → 3) linkages. This result was similar to that obtained with β-galactosidases from LAB [30][31][32]39].…”

Production of β-galactosidase from streptococcus thermophilus for galactooligosaccharides synthesis

“…It was reported that there is no obvious difference in the obtained GOS yields using either pure or crude β-galactosidase at 37°C (Splechtna et al 2007). Because of the GRAS status of S. thermophilus it is also safe to use the crude extract in food and feed applications.…”

“…Data gleaned from the literature showed that maximum GOS yield is largely influenced by initial lactose concentration (Cho et al 2003;Splechtna et al 2007;Valero 2009). This dependence on initial lactose concentration has at least two contributing factors: increased availability of saccharide galactosyl acceptors, and decreased availability of water.…”

“…The activity assay was carried out as described by Splechtna et al (2007) and Nguyen et al (2006) with some modifications. Th e chromoge nic substrate o-nitropheno l-β -Dgalactopyranoside (ONPG) (4 mg mL −1 ) was dissolved in 50 mM sodium phosphate buffer (pH 6.8).…”

“…The mobile phase was acetonitrile (75 % v/v) and distilled water (25 % v/v) filtered though a sterile micro-filter (0.45 μL) and deaerated for 20 min in ultrasonic equipment before use. Flow rate was kept at 1 mL min −1 (Neri et al 2009;MartinezVillaluenga et al 2008;Splechtna et al 2007).…”