In vitro prebiotic potential, digestibility and biocompatibility properties of laminari-oligosaccharides produced from curdlan by β-1,3-endoglucanase from .

Curdlan or laminarin, a β-1,3-glucan was hydrolysed by β-1,3-endoglucanase (Lam81A) from to produce laminari-oligosaccharides. TLC analysis of hydrolysed curdlan showed the presence of laminari-oligosaccharides of the degree of polymerization, DP2-DP7. This mixture of laminari-oligosaccharides displayed prebiotic properties. Laminari-oligosaccharides showed an increase in the growth of probiotic bacteria such as DM5 and , while they did not promote the growth of non-probiotic bacteria ( and ). Laminari-oligosaccharides showed higher prebiotic activity score of 0.92 ± 0.01 and 0.64 ± 0.08 for DM5 and NRRL B-4496, respectively, similar to those shown by inulin. Laminari-oligosaccharides showed higher resistance or low digestibility against α-amylase, artificial gastric juice and intestinal fluid than inulin indicating their bioavailability to the probiotic bacteria present in the gastrointestinal tract of human. The probiotic bacteria consumed laminaribiose and laminariotriose more readily than higher laminari-oligosaccharides as carbon source for their growth. The in vitro cytotoxicity assay of laminari-oligosaccharides (1 mg/ml) on human embryonic kidney (HEK 293) cells showed that the cell viability was not affected even after 72 h indicating their biocompatible nature. All the results amply indicated that laminari-oligosaccharides can serve as potential prebiotic additives for functional food products.