Inhibitory Effect of Purple Sweet Potato Pigments on some Microorganisms

Abstract:

Inhibitory effect of purple sweet potato pigments (PSPPs) on E. coli, Staph. aureus, Sacc. cerevisiae and Asp. niger was investigated in this paper. The results showed that E. coli and Staph. aureus could be inhibited strongly by PSPPs and dependent on the concentration of PSPPs, but no inhibitive effect of PSPPs on Sacc.cerevisiae and Asp. niger was observed. Observation under Transmission Electron Microscope was carried out and growth curve of E. coli was ploted out. It was indicated that PSPPs might change the permeability of cell membrane, make cell excrescent and inhibit cell division. As a result, cytoplasm could become thin, disassembled and even die. SDS-PAGE analysis suggested that PSPA have some influence on some proteins synthesis, but no disappearance of special protein lines be found.

Key words:Purple sweet potato, Anthocyanins, Antibacterial effect