Fractionation and characterization of ɛ-poly- l -lysine from Streptomyces albulus CGMCC 1986

摘要: ɛ-Poly-l-lysine (ɛ-PLL) produced by Streptomyces albulus CGMCC 1986 was fractionated using ultra-filtration technique with 2 and 5 kDa cut-offs of membrane. The number-average molecular weight each fraction determined 1H nuclear magnetic resonance (NMR) method. weights the cutoffs filtrate are 4,230.95, 3,687.80, 1,900.82 Da, respectively. NMR indicates chemical shifts α-H, β-H, γ-H, δ-H, ɛ-H very similar to all fractions. Fourier transform-infrared (FTIR) spectra showed that ɛ-PLL solid samples obtained freeze-drying at pH higher than take on a β-turn conformation, however, smaller adopts random coil structure. antibacterial test proved between membranes behaves highest activity other fractions for strains Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Escherichia coli, Shigella.