紫花地丁醇取物对食源性致病微生物的抑制作用

Inhibition of extracts from Viola yedoensis Makino on food-borne pathogens

以紫花地丁全株为原料,95%乙醇为提取溶剂,固液比1:30,50℃水浴浸提15 h后,浸提液经旋转蒸发、冷冻干燥、溶解,并对该醇提物的抑菌活性进行了研究。结果表明:紫花地丁醇提物对于供试的食源性致病细菌有强烈的抑制作用,且对G-菌株的抑制作用要优于G+菌株,对真菌的抑制作用有选择性,其中对供试霉菌无抑制作用。采用96孔板结合2倍梯度稀释法测定了紫花地丁醇提物对Escherichia coli,Vibrio parahaemolyticus,Staphylococcus aureus和Listeria monocytogenes的最小抑菌浓度(Minimum inhibitory concentration,MIC)均为25 mg/mL,最小杀菌浓度(Minimum bactericidal concentration,MBC)分别为100、100、200、100 mg/mL。紫花地丁醇提物对E.coli的杀菌效果显著,处理60 min,菌落数由6.74 log CFU/mL降低到1.85 log CFU/mL,处理90 min后无菌落出现;而且该醇提物稳定性较好,抑菌活性在(50~100)℃范围内无明显变化,在pH(2~12)范围内也无显著差异。研究结果说明紫花地丁全株醇提物具有稳定的抗细菌活性,在控制食源性致病细菌的食品污染方面有较高的应用潜力和开发前景。

In this study, taking the whole plant of Viola yedoensis Makino as raw material, 95% ethanol as extraction solvent with solid-liquid ratio of 1：30, at 50 ℃ for 15 h, the extract was prepared by spinevaporating, lyophilizing and re-dissolving. The antimicrobial activities of the extract were further studied. The results showed that the extract of Viola yedoensis Makino had a strong inhibitory effect on the food-borne pathogenic bacteria and the antibacterial activity on the G-strain was better than that on the G＋ strain. The inhibition against the fungi was selective and had no inhibitory effect on the tested mould. Using 96-well plates and double gradient dilution method to determine the minimal inhibitory concentrations of extract of Viola yedoensis Makino to E. coli, Vibrio parahaemolyticus, Staphylococcus aureus and Listeria monocytogenes. That were determined to be 25 mg/mL and the minimum bactericidal concentration were 100 mg/mL, 100 mg/mL, 200 mg/mL and 100 mg/mL, respectively. The bactericidal effect of the extract of Viola yedoensis Makino on E.coli was significant. The populations of E.coli were reduced from 6.74 log CFU/mL to 1.85 log CFU/mL within 60 min, and to non-detectable level（10 CFU/mL） within 90 min. The stability of the extract was good, the antibacterial activity was not changed in the range of（50~100）℃, and there was no significant difference in p H（2~12）. The results suggest that the extract of Viola yedoensis Makino has stable antibacterial activity and has a potential for application in control of food-borne pathogenic bacteria.