title: Detection of secreted antimicrobial peptides isolated from cell-free culture supernatant of Paenibacillus alvei AN5.
abstract: An antimicrobial substance produced by the Paenibacillus alvei strain AN5 was detected in fermentation broth. Subsequently, cell-free culture supernatant (CFCS) was obtained by medium centrifugation and filtration, and its antimicrobial activity was tested. This showed a broad inhibitory spectrum against both Gram-positive and -negative bacterial strains. The CFCS was then purified and subjected to SDS-PAGE and infrared spectroscopy, which indicated the proteinaceous nature of the antimicrobial compound. Some de novo sequencing using an automatic Q-TOF premier system determined the amino acid sequence of the purified antimicrobial peptide as Y-S-K-S-L-P-L-S-V-L-N-P (1,316 Da). The novel peptide was designated as peptide AN5-1. Its mode of action was bactericidal, inducing cell lysis in E. coli ATCC 29522 and S. aureus, and non-cell lysis in both S. marcescens and B. cereus ATCC 14579. Peptide AN5-1 displayed stability at a wide range of pH values (2-12) and remained active after exposure to high temperatures (100 °C). It also maintained its antimicrobial activity after incubation with chemicals such as SDS, urea and EDTA.
authors.affiliation: Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors.forename: Bassam
authors.initials: B
authors.lastname: Alkotaini
authors.forename: Nurina
authors.initials: N
authors.lastname: Anuar
authors.forename: Abdul Amir Hassan
authors.initials: AA
authors.lastname: Kadhum
authors.forename: Asmahani Azira Abdu
authors.initials: AA
authors.lastname: Sani
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D017077:Culture Media, Conditioned / Q000737:chemistry*; D005285:Fermentation; D008826:Microbial Sensitivity Tests; D056507:Paenibacillus / Q000737:chemistry* / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D017077:Culture Media, Conditioned; D010455:Peptides