Antibacterial activity of water-phase extracts from bamboo shavings against food spoilage microorganisms

Abstract

Water-phase extract of bamboo shavings (WEBS), by supercritical carbon dioxide extraction, was evaluated for its antimicrobial action against the range of food borne and food spoilage pathogens using agar disc diffusion assay in nutrient agar and Czapek Dox Agar media. The WEBS exhibited antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Aspergillus niger, Penicilliun citrinum and Saccharomyces cerevisiae with a concentration-dependent relationship. The minimum inhibitory  concentrations (MICs) of the WEBS against the tested bacterial strains were found in the range of 4.9 - 32 mg/ml using the two-fold dilution method. Different heat treatment conditions have no significant influence on the antibacterial activity. Emodin was taken as the standard sample to test for the content of total  anthraquinone compound and preliminarily verify its antibacterial mechanism, so as to lay a theoretical foundation for development of its natural preservatives.

Key words: Water-phase extract of bamboo shavings (WEBS), antimicrobial activity, natural preservative.