植物乳杆菌NCU116抑菌性能的研究

以9种常见病原菌和非病原菌作为指示菌,采用牛津杯法对植物乳杆菌NCU116发酵液、菌体及代谢产物进行体外抑菌试验。结果显示,NCU116对其中3株乳酸菌无抑制作用,对大肠埃希氏菌ATCC 25922的抑制作用最强。进一步研究了不同浓度样品、不同有机酸、排除有机酸及过氧化氢干扰以及经pH调节、热处理、酶处理后对大肠埃希氏菌ATCC 25922的抑菌活性变化。结果表明,样品浓度对抑菌效果无明显影响;产生的抑菌物质中除有机酸外还有其他活性物质,如小分子多肽类细菌素、H2O2等;低pH是产生抑菌效果的一个必要条件。综合表明,植物乳杆菌NCU116主要起抑菌作用的是菌体及其代谢产物中的各种有机酸和小分子多肽类细菌素等。

Antibacterial Experiments of Lactobacillus plantarum NCU116

L.plantarum NCU116 fermentation liquor,bacterial itself and metabolic products were studied to detect the antibacterial activity in vitro based on oxford plate assay system,using 9 species of normal pathogen and nonpathogens as indicator organisms.It was found that L.plantarum NCU116 has the strongest inhibition to Escherichia coli ATCC 25922,but has no inhibition to 3 species of probiotics.Further study included the effect of samples of different concentrations,different organic acid,eliminating interference of organic acid and hydrogen peroxide,pH adjustment,heat and enzyme treatment to anti-Escherichia coli ATCC 25922 activity.Results showed that no significant differences were seen with samples of different concentrations.The antibacterial substance contains other active materials besides organic acid,such as,low molecular weight peptide bacteriocin and hydrogen peroxide.Low content of pH is a necessity for antibacterial activity.In conclusion,antibacterial activity of L.plantarum NCU116 was attributed to itself and all sorts of organic acid,low molecular weight peptide bacteriocin.