Characterization of a novel antibacterial glycopeptide produced by Penicillium sp. M03

Abstract

Aims: To isolate a novel antibiotic termed AF from fermentation broth of Penicillium sp. M03 and to examine its antimicrobial activity, biological properties and structure characteristics. Methods and Results: Sephadex LH-20 and HPLC were used to purify AF from fermentation broth of Penicillium sp. M03. The antimicrobial activity of AF was evaluated with the agar diffusion test. Amino acid and monosaccharide composition of AF was analysed by a HITACHI 835 detector and HPLC assay, respectively. Matrix-assisted laser desorption time of flight mass spectrometry, FT-IR and 1H nuclear magnetic resonance spectra analyses were performed to examine the initial structure of AF. Eighty milligrams of AF was isolated as white powder from 1-l Penicillium sp. M03 fermentation broth. It consists of five amino acid and two monosaccharide residues and the molecular weight of it was 1017, and it was stable to β-lactamase, heat, acid and alkali. AF showed inhibitory activity to a wide range of bacteria, particularly to multidrug-resistant Staphylococcus aureus. Conclusions: AF was a novel antibacterial glycopeptide with a broad inhibitory spectrum to pathogenic bacteria including multidrug-resistant agents. Furthermore, it is difficult to generate bacteria resistant to AF. Significance and Impact of the Study: Characterization of AF made it a potential antibiotic to fight against antibiotic-resistant bacterial pathogens. © 2009 The Society for Applied Microbiology.