[论文解读] Screening of antibacterial activity of lactic acid bacteria isolated from fermented vegetables against food borne pathogens

Mahnaz Kazemipoor, Che Wan Jasimah Wan Mohamed Radzi+2 more|arXiv (Cornell University)|Jun 25, 2012

Probiotics and Fermented Foods参考文献 36被引用 26

一句话总结

本研究从家庭自制发酵蔬菜中筛选了乳酸菌（LAB），以评估其对食源性病原体的抗菌活性。采用琼脂打孔法，四种LAB菌株——动物双歧杆菌（MF6）、鼠李糖乳杆菌（MF10）、发酵乳杆菌（MF13）和植脂菌（MF15）——对革兰氏阳性菌和革兰氏阴性菌病原体均表现出强抑制作用，其中MF6对大肠杆菌（ZOI：18.7–21.3 mm）的抑制效果最广且最强。

ABSTRACT

This study aims to screen the antibacterial activity of lactic acid bacteria (LAB) isolated from home-made fermented vegetables against common food borne pathogens. The antagonistic properties of these isolates against Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica and Bacillus cereus were examined using agar well diffusion method. Four LAB namely MF6, MF10, MF13, and MF15 identified as Lactobacillus animalis, Lactobacillus rhamnosus, Lactobacillus fermentum and Lactobacillus reuteri, respectively were effective against all selected pathogenic strains. Amongst the four isolates, MF6 exhibited the highest antibacterial activity, against all the indicator pathogens tested except Y. enterocolitic. Its activity was maximum against E.coli with a Zone of Inhibition (ZOI) ranging from 18.7 to 21.3 mm and least for Y. enterocolitica (10 \pm 1.1 mm). Isolate MF13 also showed antimicrobial property against all tested pathogens showing highest activity against Y. enterocolitica (14 \pm 1.7 mm) and least against E.coli (8 \pm 1.4 mm), which was in direct contrast to isolate MF6. Isolate MF15 showed greater activity against E.coli (12 \pm 0.8 mm) and least against S. aureus (8 \pm 1.7 mm). Least antimicrobial property was observed in isolate MF10, with a ZOI in the range of 2.5-7 mm. The degree of antimicrobial property among the isolates was in the order of MF6>MF13>MF15>MF10. Overall, the isolated LAB showed the remarkable inhibitory effect against both Gram positive and Gram negative pathogenic strains. However, the spectrum of inhibition was different for the isolates tested. These results suggest that this potent isolates could be used as a natural biopreservatives in different food products.

研究动机与目标

• 从家庭自制发酵蔬菜中分离并鉴定乳酸菌（LAB）。
• 评估这些LAB分离株对常见食源性病原体的抗菌活性。
• 确定不同LAB菌株对不同病原体的抑制谱和效力。
• 筛选适合用作食品体系中天然生物防腐剂的优良LAB候选菌株。
• 比较不同LAB分离株对革兰氏阳性和革兰氏阴性病原体的抗菌效力。

提出的方法

• 使用选择性培养基从家庭自制发酵蔬菜中分离乳酸菌（LAB）。
• 采用标准微生物学和生化方法将LAB分离株鉴定至种水平。
• 通过琼脂打孔法对四种食源性病原体（大肠杆菌、金黄色葡萄球菌、小肠结肠炎耶尔森菌和蜡样芽孢杆菌）进行抗菌活性筛选。
• 测量含有细菌上清液的孔周围抑菌圈（ZOI）大小，以量化抗菌活性。
• 对不同分离株和病原体的ZOI值进行统计比较，评估其相对效力。
• 根据抗菌谱和效力对分离株进行分类。

实验结果

研究问题

• RQ1 从发酵蔬菜中分离出的哪些乳酸菌对常见食源性病原体表现出显著的抗菌活性？
• RQ2 不同LAB分离株对革兰氏阳性和革兰氏阴性病原体的抗菌效力有何差异？
• RQ3 哪种LAB分离株对所测试病原体表现出最广谱且最强的抑制活性？
• RQ4 LAB分离株的种类与其抑制谱之间存在何种关系？
• RQ5 这些LAB分离株是否可作为食品产品中天然生物防腐的可行候选？

主要发现

• MF6（动物双歧杆菌）表现出最高的整体抗菌活性，对大肠杆菌的抑菌圈（ZOI）为18.7–21.3 mm，为所有测试分离株和病原体中的最高值。
• MF6对小肠结肠炎耶尔森菌表现出中等活性（ZOI：10 ± 1.1 mm），表明其抑制能力存在菌株特异性差异。
• MF13（发酵乳杆菌）对Y. enterocolitica的活性最强（ZOI：14 ± 1.7 mm），与MF6的模式相反，凸显了病原体特异性抑制特性。
• MF15（植脂菌）对大肠杆菌的活性最高（ZOI：12 ± 0.8 mm），而对金黄色葡萄球菌的活性最低（ZOI：8 ± 1.7 mm），表明其对不同病原体的效力存在差异。
• MF10（鼠李糖乳杆菌）表现出最弱的抗菌活性，其ZOI值在所有测试病原体中均介于2.5至7 mm之间。
• 各分离株抗菌效力的总体顺序为：MF6 > MF13 > MF15 > MF10，且所有四种分离株均对革兰氏阳性和革兰氏阴性病原体表现出显著的抑制作用。