Figure 2.

β-glucan utilizing mechanisms in Gram-negative bacteria and Gram-positive. (A) Gram-negative bacteria can hydrolyze polysaccharides at the outer membrane tendered glycoside hydrolase (GH) and convert into oligosaccharides. Those polysaccharides first recognize by surface glycan-binding protein and facilitate endo-acting enzymes to cleave them. Generated oligosaccharides are again caught by SusD, and it allows them to enter the periplasmic space through TonB - dependent transporter (SusC homolog). Entered oligosaccharides further cleave into monosaccharide contents by periplasmic GH. Those monosaccharides pass to the cytoplasm via Major Facilitator Superfamily (MFS) transporter and produce bacterial metabolites (including SCFAs) through fermentation to promote the host’s health. HTCS, hybrid two-component system sensor/regulator. (B) Similarly to Gram-negative bacteria, Gram-positive bacteria hydrolyze polysaccharides at the outer membrane tendered GH and convert into oligosaccharides. Generated oligosaccharides enter into cytoplasmic space through MFS, the phosphoenolpyruvate (PEP)- carbohydrate phosphotransferase system (PTS), or ATP-binding cassette (ABC) transporters couple ATP hydrolysis. SCFAs: short-chain fatty acids.