Assessment of the biological potential of cell-free supernatant of Lysinibacillus odysseyi from buffalo milk

The cell-free supernatant of bacteria contains naturally produced secondary metabolites that have antibacterial, antioxidant, anti-inflammatory, and anticancer properties, which have significant results for the therapeutic field. The isolated strain was identified as Lysinibacillus odysseyi VSS53 (accession number PP112153) through biochemical and morphological analysis. An antibiotic susceptibility test using 14 antibiotics on the isolated bacterium showed sensitivity to eight, intermediate sensitivity to four, and resistance to two antibiotics. The biosafety assessment through hemolytic and gelatinase assays indicates that the isolated bacterium has been verified as safe. The chemical composition of the cell-free supernatant (CFS) was analyzed using UV–Vis, FT-IR, and GC-MS. The stability and size of the CFS were determined through zeta potential and particle size analysis. The maximum inhibition of antioxidant activity using DPPH (29.94 %), the phosphomolybdate antioxidant assay (68.63 %), the FRAP assay (67.4 %), and the nitric oxide activity (26.23 %). Additionally, the anti-inflammatory activity maximum inhibition is 61.3 %. The antibacterial activity against six pathogenic bacterial strains was examined, with the maximum zone of inhibition observed at 100 mg/mL, and antibiofilm activity results showed the highest percentage inhibition at the 0.1 mg/ml of CFS. The anticancer activity against the MDA-MB-231 cell line, with an IC₅₀ value of 0.00705 mg/ml. Toxicity analysis of the CFS using Artemia franciscana showed healthy growth after 24 and 48 h of observation. In conclusion, the CFS of L. odysseyi has therapeutic uses due to its ability to eliminate microorganisms and cancer cells. Future advancements in medicine could potentially harness these advantageous properties of the CFS of L. odysseyi.