Purification and characterization of a novel bacteriocin produced by Acinetobacter movanagherensis AS isolated from goat rectum

Abstract

The present investigation focuses on the purification and characterization of a novel bacteriocin produced by Acinetobacter movanagherensis AS isolated from goat rectum, which demonstrated high antimicrobial activity against both gram-positive and gram-negative bacteria. It was identified as A. movanagherensis AS using biochemical and 16S rDNA sequencing. Tryptic soy broth supplemented with 1% yeast extract with pH 6.5 and incubation temperature of 37°C for 32 h were the optimal conditions for bacteriocin production. Bacteriocin was purified in three steps: 70% ammonium sulfate precipitation, ion-exchange chromatography with diethylaminoethyl-cellulose resin, and size exclusion chromatography with a Sephadex G75 column. Purified bacteriocin had a recovery of 7.93% with 23.43 purification fold, and a molecular weight of 12.11 kDa was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Its biochemical characterization showed good stability at a broad range of temperature (40–80°C) as well as pH (3–9). Inhibition of antimicrobial activity was observed after treatment with trypsin, pepsin, and protease, which confirmed the proteinaceous nature of the purified bacteriocin. Bioinformatic analysis suggests that the purified novel bacteriocin from A. movanagherensis AS may belong to the colicin family. Considering the antimicrobial potential of purified bacteriocin coated on low-density polyethylene film, we assume that it could be potentially exploited for food preservation in food processing industries.