A study on microbial mucin utilizers from healthy Indian adult human faeces

The human gut is sheltered by overwhelming number of complex microorganisms, including mucin utilizers that play a significant role in host health and diseases. It is speculated that only 0.9% of faecal flora participates in the degradation of mucin molecules, and less than 100 such bacterial strains have been identified and a few were reported as probiotic candidate. The knowledge of the bacterial population that facilitates mucin degradation is still in infancy, as a significant proportion of the microbiota in mucin neither been cultured nor fully elucidated till now. In present investigation, different human derived mucolytic bacteria have been isolated and characterized. The data exhibited different mucus utilizing strains viz. Enterococcus (3), Priestia (2), Shigella (3) and Escherichia (1) via meta-genomic technique. The amido black assay implies that these isolates produce a halo around the colony that manifests the release of mucin degrading enzyme. Further, the findings of decrease in carbohydrate concentration in the range of 45-77% and protein content of 4-24% in mucin enriched spent medium confirmed the ability of strains to degrade mucin. Additionally, the enzymatic data reveal our isolated secrete inconsiderable amount of sialidase, α- galactosidase, β-galactosidase, α- glucosidase and β-glucosidase, that cleave mucin oligosaccharide chains. Further, the cell hydrophobicity results revealed all culture show low hydrophobicity (2-30%) and antibiotic susceptibility data manifested variation in antibiotic resistance profile. Safety analysis parameters such as haemolytic assay, gelatinase and, antibiotic susceptibility showed that the E. gallinarium KS4 and P. flexa KS1 lack virulence traits. Also, better acclimatization of E. gallinarium KS4 and P. flexa KS1 strain under in vitro gut conditions suggests they could act as a prominent probiotic candidate for human and amend intestinal integrity.