title: Biochemical Properties and Mechanism of Action of Enterocin LD3 Purified from Enterococcus hirae LD3.
abstract: Enterocin LD3 was purified using activity-guided multistep chromatography techniques such as cation-exchange and gel-filtration chromatography. The preparation's purity was tested using reverse-phase ultra-performance liquid chromatography. The specific activity was tested to be 187.5 AU µg(-1) with 13-fold purification. Purified enterocin LD3 was heat stable up to 121 °C (at 15 psi pressure) and pH 2-6. The activity was lost in the presence of papain, reduced by proteinase K, pepsin and trypsin, but was unaffected by amylase and lipase, suggesting proteinaceous nature of the compound and no role of carbohydrate and lipid moieties in the activity. MALDI-TOF/MS analysis of purified enterocin LD3 resolved m/z 4114.6, and N-terminal amino acid sequence was found to be H2NQGGQANQ-COOH suggesting a new bacteriocin. Dissipation of membrane potential, loss of internal ATP and bactericidal effect were recorded when indicator strain Micrococcus luteus was treated with enterocin LD3. It inhibited Gram-positive and Gram-negative bacteria including human pathogens such as Staphylococcus aureus, Pseudomonas fluorescens, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Listeria monocytogenes, Escherichia coli O157:H7, E. coli (urogenic, a clinical isolate) and Vibrio sp. These properties of purified enterocin LD3 suggest its applications as a food biopreservative and as an alternative to clinical antibiotics.
authors.affiliation: Department of Genetics, Maharshi Dayanand University, Rohtak, Haryana, 124001, India.|Department of Bioscience and Biotechnology, Banasthali University, Tonk, Rajasthan, 304022, India.
authors.forename: Aabha
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Genetics, Maharshi Dayanand University, Rohtak, Haryana, 124001, India. santoshgenetics@gmail.com.|Department of Bioscience and Biotechnology, Banasthali University, Tonk, Rajasthan, 304022, India. santoshgenetics@gmail.com.|Health Promoting Naturals Laboratory, School of Environmental and Biological Sciences, Rutgers State University, New Brunswick, NJ, 08901, USA. santoshgenetics@gmail.com.
authors.forename: Santosh Kumar
authors.initials: SK
authors.lastname: Tiwari
authors.affiliation: Health Promoting Naturals Laboratory, School of Environmental and Biological Sciences, Rutgers State University, New Brunswick, NJ, 08901, USA.
authors.forename: Victoria
authors.initials: V
authors.lastname: Netrebov
authors.affiliation: Health Promoting Naturals Laboratory, School of Environmental and Biological Sciences, Rutgers State University, New Brunswick, NJ, 08901, USA.|Center for Digestive Health, New Jersey Institute for Food, Nutrition and Health, New Brunswick, NJ, 08901, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Chikindas
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects*; D001952:Bridged-Ring Compounds / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000070076:Enterococcus hirae / Q000737:chemistry / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001952:Bridged-Ring Compounds; C012306:enterocin
keywords: Bacteriocin; Biopreservation; Enterocin LD3; Enterococcus hirae LD3; Membrane potential