Pectic oligosaccharides hydrolyzed from orange peel by fungal multi-enzyme complexes and their prebiotic and antibacterial potentials.

Orange peel wastes were enzymatically depolymerized into pectic oligosaccharides (POS) by multi-enzyme complexes from Aspergillus japonicus PJ01. The hydrolyzate was fractionated via membrane separation into three fractions: POS1 <1 kDa; 1 kDa < POS2 < 3 kDa; POS3 > 3 kDa. Compositional analysis showed that these fractions were rich in glucose, arabinose, and galacturonic acid. The prebiotic potentials of these fractions were evaluated via single culture with Bifidobacterium infantis , Lactobacillus acidophilus , Clostridium perfringens , and Bacteroides fragilis . Results showed that POS2 had higher prebiotic property than POS1 and 3, and it was comparable to fructooligosaccharide. In mixed culture, POS2 showed positive effect on B. infantis , while negative effect on B. fragilis according to the results of real-time quantitative PCR analysis. The antimicrobial activities of the POS were examined by typical bacteria Staphylococcus aureus , Bacillus subtilis , and Escherichia coli. Results showed that POS1 and 2 had higher antimicrobial activities than POS3. [ABSTRACT FROM AUTHOR]