Nisin Induced Morphological Changes and Disruption of Growth in Eschericia.Coli

Abstract

Nisin is a 34 residue long cationic lanthionine antibiotic produced by Lactococcus lactis and antimicrobial activity against a broad spectrum of gram-positive bacteria. During its antimicrobial action it is known to target intermediates in the bacterial cell wall biosynthesis, lipid II, and undecaprenyl pyrophosphate. Recent discoveries of lipid II as a target for nisin has brought nisin to the forefront, as a model case, in the battle against antibiotic resistance and assessing the combination of using conventional antibiotics with nisin remain to be explored. Here we evaluated the effect of antimicrobial activity of Nisin on E.coli by determining the MIC (Minimum inhibitory concentration), MBC (Minimum bactericidal concentration), Zeta potential (electrokinetic potential), SEM (Scanning electron microscopy), in the presence and absence of Ampicillin. We observe that increasing concentrations of Nisin drastically prolong the lag phase of E.coli and cause excessive delay in reaching the stationary phase.Nisin is highly active against gram positive bacteria, but it is quite pleasing finding that it is also effective in the case of E.coli which is a gram negative bacteria.