Bio-physico-chemical characterization of BLIS from aquatic bacteria

Although more than 200 bacteriocins have been isolated yet numerous antimicrobial compounds or BLIS are still to be fully characterized. The aim of the current study was to characterize novel significant aquatic. Bacteriocins like inhibitory substance (BLIS). The two most significant and thermostable bacteriocinogenic aquatic strains were chosen out of previously isolated 10 strains for bio-physico-chemical characterization and identified as Bacillus coagulans and Bacillus spp. (ZP-108). Our findings showed that the bacteriocin was sensitive to trypsin as partially losing activity after enzyme treatment indicating the inhibitory substance contains the proteinaceous nature. The arbitrary units of Bacillus coagulans were 12500/mL having two weeks shelf life, while Bacillus spp. (ZP-108) having three weeks shelf life and 1250 arbitraty units/mL. Bacteriocinogenesis was optimum in Nutrient agar medium having 0.5% concentration of NaCl. Cell free neutralized supernatant (CFNS) of aquatic bacteriocinogenic strains exhibited activity within a wide pH range of 1-11 for Bacillus coagulans and 1-9 for Bacillus spp. (ZP-108). Bacillus spp. (ZP-108) was stable against organic solvents like methanol, acetone and chloroform while Bacillus coagulans against ethanol. Both strains were also resistant to the surfactant SDS. Even against other organic solvents and surfactants tested none of the strains lost more than 25% of their residual activity. Altogether the findings of the present study strongly suggest that both the thermostable bacteriocins having high titer and quite resistant to wide range of pH, organic solvents and surfactants can have a great potential for the broad based practical applications.