Bacterial Protease Inhibitors as Antibacterial agents to prevent Bacterial Infections Associated with Biofilms

Isolation of protease inhibitor producing bacteria from microbial mat and investigating its anti-biofilm potential against biofilm producing organism was selected as the main objective of the present study. Protease inhibitor (PI) was produced from bacterial isolates and purified using ammonium sulphate precipitation methods. Primary and secondary protease inhibitor assay was carried out separately to confirm the inhibition of protease enzyme activity both qualitatively and quantitatively. Antibacterial activity and anti-biofilm assay was performed to determine the biofilm prevention capabilities of PI. Three isolates (B1PI, B2PI and B3PI) were screened and B2PI bacterial culture was selected based on the results of primary and secondary protease inhibitor assay. Maximum trypsin inhibition of 77.5±0.25% was recorded for the isolate B2PI. Antibacterial activity of the B2PI protease inhibitor fractions exhibited inhibitory zones of 22.3±1.04mm and 20.2±0.25mm against Escherichia coli and Staphylococcus aureus respectively. Anti-biofilm assay of protease inhibitor fractions expressed 31.2μl/ml of MBIC against Escherichia coli and Staphylococcus aureus. The results conclude that, the protease inhibitor from the microbial mat isolate will be an effective alternative to the commercial antibiotics either alone or in combination with other drugs synergistically which shall be studied elaborately in future.