Exploring the production and functional properties of peptides derived from lysinibacillus fusiformis

Rhizospheric bacteria are an important reservoir of bioactive metabolites for biomedical purposes. In the present study, individual bacterial colonies were selected from rhizosphere soil, and a morphologically different isolate designated MGR 24 was obtained. Based on morphological and biochemical characteristics, along with 16S rRNA gene sequence analysis, the isolate was identified as Lysinibacillus fusiformis MGR 24. Growth optimization studies identified carbon, nitrogen, and micronutrient composition as the most influential factors affecting biomass formation and product yield. Antimicrobial peptide expression was associated with the growth phase, and maximal activity (≈3100 AU/mL) was observed at 11–12 h of incubation. SDS-PAGE analysis revealed a major extracellular protein component of approximately 96 kDa. Enzymatic management and digestion studies were carried out to ascertain the proteinaceous nature of the compound. The peptide was highly tolerant to temperature and pH and retained its original activity even after purification by cation-exchange chromatography, with a 40-fold enrichment of lyase and 80% recovery. LC–MS analysis revealed several peaks, including a major molecular ion at m/z 265.2663. These results emphasize L. fusiformis MGR 24 as a promising candidate for the stable isolation of antimicrobial peptides for further exploration of sensory properties.