Marine Macroalga-associated Bacillus amyloliquefaciens as Prospective Probiotic

ABSTRACT

Heterotrophic Bacillus amyloliquefaciens (MTCC 12716) isolated from the red alga Hypnea valentiae exhibited promising antibacterial activity (minimum inhibitory concentration of ≤1.0 µg/mL) against clinically relevant pathogens. The bacterium displayed bile salt and acid tolerance up to 4 h in a simulated gastric fluid, along with a prospective antioxidant effect. This non-hemolytic bacterium was found to be sensitive to a panel of antibiotics and did not amplify the enterotoxin-specific genes. In order to analyze the possibilities of scaling up, we have optimized the growth of B. amyloliquefaciens by response surface methodology to realize maximum production of anti-infective agents in the fermentation medium and observed an increment of about 85% antibacterial activity against gastrointestinal pathogens. As probiotic treatment is useful due to its ability to recreate the natural intestinal microflora, this heterotrophic Bacillus could be contemplated to offer a prospective probiotic. Further studies are needed to assess its utility for commercial application.

KEYWORDS:

• Macroalga-associated Bacillus amyloliquefaciens
• probiotic effects
• gastrointestinal pathogens
• antibacterial activity
• enterotoxin specific genes

Acknowledgments

This work was supported by funding under Kerala State Council for Science, Technology and Environment (Grant No. 040/FSHP-LSS/2014/KSCSTE) and Indian Council of Agricultural Research (ICAR) under “Development of Bioactive Pharmacophores from Marine Organisms” (grant number MBT/HLT/SUB23). The authors thank the Director, Central Marine Fisheries Research Institute and Dean, Faculty of Marine Sciences, Lakeside Campus, Cochin University of Science and Technology for the support. Thanks are due to the Head, Marine Biotechnology Division, Central Marine Fisheries Research Institute for facilitating the research activities. V.K.K. expresses sincere thanks to Kerala State Council for Science, Technology and Environment for financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10498850.2021.1974140.

Additional information

Funding

This work was supported by the ICAR [MBT/HLT/SUB23]; Kerala State Council for Science, Technology and Environment [040/FSHP-LSS/2014/KSCSTE].