In vitro bioefficacy of different antimicrobial peptides against different pathovers of xanthomonas using paper disc and micro-dilution broth method

In vitro bioefficacies of the different antimicrobial peptides (AMPs) were tested against three bacteria using paper disc and micro-dilution broth method. Nine different cationic AMPs viz. D4E1, PEP11, ESF1, ESF4, ESF5, ESF6, ESF12, ESF13 and ESF17 exhibiting variable amino acid compositions and charges, were used for the present investigation. Among the various AMPs tested against Xanthomonas axonopodis pv. punicae (Xap), Xanthomonas axonopodis pv. citri (Xac) and Xanthomonas axonopodis pv. malvacearum (Xam) ,the peptide D4E1 (net charge + 8) was the most effective AMP against all the three Xanthomonas sp. followed by PEP11, ESF12 and ESF1 having net charge +4. The peptide ESF13 was not effective against all the three bacteria while ESF4 was not effective against Xap and Xac whereas ESF6 was also not effective against Xac.AntiMicrobial peptides when tested in vitro through micro-dilution broth method showed that the inhibition growth per cent against Xap was greater than 90% ([MIC.sub.90]) for D4E1, PEP11, ESF17, ESF5 and ESF12. For Xac, D4E1, PEP11, ESF17, ESF5, ESF6, ESF1 and ESF12 showed the inhibition growth percent greater than 90% ([MIC.sub.90]). For Xam, the inhibition growth per cent was seen greater than 90% ([MIC.sub.90]) for D4E1, PEP11, ESF17, ESF1 and ESF12. The most promising peptide D4E1 exhibited better stability against endogenous proteases which recorded only 10.08% hemolysis at a very high i.e.100 [micro]M concentration.The D4E1 peptides appears to be a promising candidate to be explanted through gene manipulation to control bacterial blight of pomegranate. Keywords: Anti-Microbial Peptides, Bioefficacy, Xanthomonus sp., Inhibition.