Factors affecting the production of lactulose by Lactobacillus acidophilus NRRL 4495 β-galactosidase and its biological activity

Aim: Production of lactulose and other oligosaccharides by Lactobacillus acidophilus NRRL 4495 a-galactosidase andtheir biological activity. Methodology and Results: The transgalactosylation activity of Lactobacillus acidophilus NRRL 4495 B-galactosidase was investigated under different conditions for synthesis of lactulose and oligosaccharides. The synthesis was optimized with respect to pH; time; enzyme concentration and substrates ratio (lactose: fructose). Maximum production forlactulose was found to be 25 g/L at pH 6.6 with 40: 20% (w/v) lactose to fructose, respectively and enzyme concentration 4 IU/mL after 7 h. With respect to the other oligosaccharides the maximum yield (19 .68 g/L) was obtained under the same conditions but with enzyme concentration 2 IU/mL and after 10 h. As a new pharmaceutical application the produced lactulose and oligosaccharide and their sulfated derivative were found to have fibrinolytic activity, but theyfailed to act as anticoagulant. Conclusion significance and impact of study: the research leads to increase the production of lactulose and other oligosaccharides with a significant yield and discovered a new pharmaceutical application for all the products.