Co-culture fermentations suggest cross-feeding among Bacteroides ovatus DSMZ 1896, Lactiplantibacillus plantarum WCFS1 and Bifidobacterium adolescentis DSMZ 20083 for utilizing dietary galactomannans

Galactomannans from sources like guar, fenugreek, locust bean, and copra form an important part of human diet. In this study, we have attempted to understand the cross-feeding and resource sharing between a generalist degrader and probiotic utilizers for utilizing dietary galactomannans. In mono-cultures, Bacteroides ovatus DSMZ 1896 grew maximally on substituted galactomannans and produced high amount of succinate. Polysaccharide break down products [β-manno-oligosaccharides; degree of polymerization (DP) 2–4] left after the growth of B. ovatus DSMZ 1896 in galactomannan supplemented media supported the growth of Lactiplantibacillus plantarum WCFS1 (DP2 and DP3) and Bifidobacterium adolescentis DSMZ 20083 (majorly DP3) and led to the production of lactate and acetate, respectively as the major end products. Co-cultures (bi- and tri-cultures) studies demonstrated cross-feeding being used as a strategy for resource sharing among B. ovatus DSMZ 1896, L. plantarum WCFS1 and B. adolescentis DSMZ 20083 while foraging galactomannans. Structure and DP of galactomannan substrates altered the SCFA and organic acid production patterns in co-cultures.