title: Interfacial assembly at silver nanoparticle enhances the antibacterial efficacy of nisin.
abstract: Nisin is a well-recognised antimicrobial peptide (AMP) used in food industry. However, efficacy of the peptide has been compromised due to development of resistance in different bacterial strains. Here, efficacy of the peptide upon assembly at a silver nanoparticle (AgNP) interface has been characterized. To this end, experimental and simulation studies are done to characterize the interfacial assembly of nisin and underlie antibacterial mechanism. Being an AMP, efficacy of an intact nisin is explored against Gram-positive and Gram-negative bacteria, and compared with antibacterial propensity of the interfacially assembled nisin. Antibacterial propensity, upon the assembly, increases against both kinds of bacteria. Interestingly, the growth inhibition studies of the interfacially assembled nisin indicate that the originally nisin resistant Gram-negative bacteria become sensitive to the nanomolar nisin concentrations. Furthermore, reactive oxygen species (ROS) measurements together with confocal microscopy imaging indicate that the increase in interfacial and intracellular ROS production upon the treatment is underling mechanism of enhanced antibacterial propensity of the assembled nisin. Thus, the study observed that the interfacial assembly of nisin at AgNP interface enhances the efficacy of nisin against different spectrum of bacteria, where the intact nisin is largely ineffective for the studied concentrations.
authors.affiliation: Department of Life Science, National Institute of Technology Rourkela, Odisha 769008, India.
authors.forename: Manoranjan
authors.initials: M
authors.lastname: Arakha
authors.affiliation: Department of Molecular Biology and Biotechnology, Tezpur University, Assam 784028, India.
authors.forename: Sapna M
authors.initials: SM
authors.lastname: Borah
authors.affiliation: Department of Life Science, National Institute of Technology Rourkela, Odisha 769008, India.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Saleem
authors.affiliation: Department of Molecular Biology and Biotechnology, Tezpur University, Assam 784028, India.
authors.forename: Anupam N
authors.initials: AN
authors.lastname: Jha
authors.affiliation: Department of Life Science, National Institute of Technology Rourkela, Odisha 769008, India. Electronic address: jhas@nitrkl.ac.in.
authors.forename: Suman
authors.initials: S
authors.lastname: Jha
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009561:Nisin / Q000737:chemistry / Q000494:pharmacology*; D011514:Proteus vulgaris / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D017382:Reactive Oxygen Species / Q000819:agonists* / Q000378:metabolism; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D017382:Reactive Oxygen Species; D009561:Nisin; D012834:Silver
keywords: Antibacterial agent; Bacteria; Fluorescence microscope; Reactive oxygen species; Silver nanoparticle