Antimicrobial potential of secondary metabolites and DNA gyrase B blocking molecules produced by a halophilic bacterium Virgibacillus salarius (MML1918)
Manivannan Nandhagopal, Ramprasath Chandrasekaran, Mathivanan Narayanasamy- Applied Microbiology and Biotechnology
- General Medicine
- Biotechnology
Abstract
Aim
The present study aims to determine the antimicrobial potential of V. salairus (MML1918) against human pathogens and its In-vitro and In-silico properties.
Methods and results
In this present study totally 63 halophilic bacterial cultures were obtained and cultivated in nutrient broth medium containing 8% NaCl and the metabolites, were extracted using ethyl acetate and screened for their antimicrobial property by cell viability assay against twelve pathogenic bacteria and fungi, among 63 halophilic bacteria the Virgibacillus salaries (MML1918) found to be best producer for secondary metabolites production against clinical pathogens. The optimization of growth for important physio-chemical parameters was characterized and applied for different production media and based on its highest activity as 17.5 ± .07 mm Zone of Inhibition (ZOI) for Bacillus cereus followed by 17.5 ± 00 mm ZOI for Staphylococcus aureus the production medium ATCC1097 was chosen for mass production. The mass production of secondary metabolites from V. salaries MML1918 was carried out in a fermenter under controlled conditions and crude metabolites was extracted and condensed. The antimicrobial activity of crude metabolites showed B. cereus (19.3 ± 0.5 mm ZOI), S. aureus, and C. albicans (18.3 ± 0.5 mm ZOI) as the highest zone of inhibition in production media for halophilic bacteria ATCC1097. Further, the GC-MS analysis showed 24 compounds present in crude metabolites. Among the 24 compounds 4, four molecules were found to be important based on molecule percentage in crude and structural similarity. The molecular docking studies show that the selected four molecules effectively bind with the active region DNA Gyrase B.
Conclusion
V. salarius (MML1918) effectively showed antimicrobial activity against several pathogenic organisms and can be employed as a suitable candidate for producing novel antimicrobial agents.