Cellulolytic potential of probiotic Bacillus Subtilis AMS6 isolated from traditional fermented soybean (Churpi): An in-vitro study with regards to application as an animal feed additive

Abstract

The aim of the present study is to evaluate the probiotic attributes of Bacillus subtilis AMS6 isolated from fermented soybean (Churpi). This isolate exhibited tolerance to low pH (pH 2.0) and bile salt (0.3%), capability to autoaggregate and coaggregate. AMS6 also showed highest antibacterial activity against the pathogenic indicator strain Salmonella enterica typhimurium (MTCC 1252) and susceptibility towards different antibiotics tested. The isolate was effective in inhibiting the adherence of food borne pathogens to Caco-2 epithelial cell lines, and was also found to be non-hemolytic which further strengthen the candidature of the isolate as a potential probiotic. Further studies revealed B. subtilis AMS6 showed cellulolytic activity (0.54±0.05 filter paper units mL(-1)) at 37°C. The isolate was found to hydrolyze carboxymethyl cellulose, filter paper and maize (Zea mays) straw. The maize straw digestion was confirmed by scanning electron microscopy studies. The isolate was able to degrade filter paper within 96h of incubation. A full length cellulase gene of AMS6 was amplified using degenerate primers consisting of 1499 nucleotides. The ORF encoded for a protein of 499 amino acids residues with a predicted molecular mass of 55.04kDa. The amino acids sequence consisted of a glycosyl hydrolase family 5 domain at N-terminal; Glycosyl hydrolase catalytic core and a CBM-3 cellulose binding domain at its C terminal. The study suggests potential probiotic B. subtilis AMS6 as a promising candidate envisaging its application as an animal feed additive for enhanced fiber digestion and gut health of animal.

Bacillus As Potential Probiotics: Status, Concerns, and Future Perspectives

“…Bacillus strains are also getting recognition as potential probiotics which could promote human health by direct consumption of high concentrations of viable number of cells ( Abdhul et al, 2015 ; Manhar et al, 2016 ). Several Bacillus probiotic strains have been approved by regulatory agencies of different countries for human use and are popular as general health promoting pharmaceutical formulations in global market ( Table 1 ).…”

Molecular Identification of Lactic acid bacteria Isolated from Lactating Cattle Lower Gut as a Potential Probiotic Species

“…Enzymatic potential: To detect the cellulolytic ability of the isolate, media described by Manhar et al (2016) was used. To determine amylolytic activity, starch (1g) and nutrient agar (1g) were dissolved in distilled water (100 ml) and pure bacterial culture was grown on it.…”

“…Probiotic species have tendency to adapt to the environment in the cattle gut due to tolerance to bile acid, affinity to glycoprotein and intestinal mucosa. They also have properties of hydrophobicity, aggregation for colonization, mucin binding property and ability to adhere to intestinal epithelium of the host (Manhar et al, 2016). They synthesize bactericidal proteins and bacteriocins which are unfavorable for pathogens.…”

Draft genome sequence data of Lysinibacillus fusiformis strain GM, isolated from potato phyllosphere as a potential probiotic

“…We identified a gene encoding a cellulase (glycosylhydrolase family 5 (pfam00150)), responsible for the cleavage of cellulose in the external environment. Cellulase converts the highly recalcitrant cellulose to fermentable mono- and oligosaccharides that can be easily assimilated in the body, thereby improving utilization of dietary carbohydrate and enhancing digestion [3] . In addition to genes responsible for cellulolytic activity, the genes of other hydrolytic enzymes – proteinases – were identified.…”