Detection of secreted antimicrobial peptides isolated from cell-free culture supernatant of Paenibacillus alvei AN5

作者：Alkotaini Bassam; Anuar Nurina^*; Kadhum Abdul Amir Hassan; Sani Asmahani Azira Abdu

来源：Journal of Industrial Microbiology and Biotechnology, 2013, 40(6): 571-579.

DOI：10.1007/s10295-013-1259-5

• Paenibacillus alvei AN5
• Antimicrobial peptide AN5-1
• LC/ESI-MS
• Action mode
• Stability

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 A degrees C). It also maintained its antimicrobial activity after incubation with chemicals such as SDS, urea and EDTA.

• 出版日期2013-6