Production, characterization, and prebiotic activity of oligosaccharides from konjac glucomannan by Bacillus amyloliquefaciens WX-1

Konjac glucomannan (KGM) oligosaccharides from KGM is a potentially and valuable prebiotics. A KGM degrading strain was screened and identified as Bacillus amyloliquefaciens WX-1. B. amyloliquefaciens WX-1 was shown to efficiently depolymerize KGM and produce a broad range of small molecule oligosaccharides. The strain efficiently processed KGM with 752.9 mg g−1 yields of KGM oligosaccharides (KGOS) at optimal conditions. The KGOS were characterized using TLC, MALDI-TOF-MS and NMR spectroscopy. The result of KGOS composition revealed that it contained a series of oligosaccharides with a degree of polymerization of 2–14 and the disaccharide structures of MM, MG and GM were assumed. The prebiotic function of KGOS to the growth of Lactobacillus was evaluated. This study showed that B. amyloliquefaciens WX-1 provided a basis for the further development as biocatalyst for direct conversion of polysaccharides derived from energy crops as well as agricultural residues to functional prebiotics.