紫背天葵提取物的抑菌活性研究

Study on Antimicrobial Effect of the Extracts from Gynura

研究紫背天葵提取物对食品中常见腐败菌的抑菌效果.以大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、啤酒酵母、黑曲霉作为供试菌种,采用滤纸片扩散法和二倍稀释法进行抑菌试验.结果表明:紫背天葵提取物对细菌抑制作用明显,其次是酵母菌,对霉菌无抑制作用;水提取物抑菌效果优于80%乙醇提取物;在pH5～9范围内都具有抑菌活性,在明显碱性环境抑菌作用最强;有良好的热稳定性.

The inhibition of microorganisms by the extracts from Gynura was studied. Five microbial strains including Escherichia coil, Staphylococcus aureus, Bacillus subtilis, Saccharomyces cerevisiae, Aspergillus niger were chosen to investigate the antimicrobial activity by disk diffusion method and double dilution method. The results showed that the extracts had better effect on bacterium than yeast, and no effect on mould. It was also proved that the extracts had antibacterial effect in the pH range of 5 to 9, but that it can be more effective in alkaline condition. Furthermore, the extracts had good thermal stability.