茶多酚对植物乳杆菌、金黄色葡萄球菌和大肠杆菌生长的双向调节作用

Dual-directional Regulation of Tea Polyphenols on the Growth of Lactobacillus plantarum,Staphylococcus aureus,and Escherichia coli

增强益生菌产品中益生菌的活力,同时抑制食源性致病菌及腐败菌的生长能够提升产品品质稳定性。在单培养及共培养条件下,采用传统计数法和高通量测序比较研究了不同浓度的茶多酚对益生菌植物乳杆菌、致病菌金黄色葡萄球菌和大肠杆菌生长的影响。单培养结果显示,随着茶多酚浓度增加,植物乳杆菌活菌数先增加后降低,在浓度为2.0 mg/mL时活菌数最多,而两株致病菌的存活率不断降低,其中金黄色葡萄球菌更为明显。在共培养体系中(金黄色葡萄球菌/大肠杆菌-植物乳杆菌),随着培养时间延长,植物乳杆菌的生物量不断增加,而致病菌数量和培养基pH不断降低。此外,高通量测序进一步表明植物乳杆菌与致病菌共存时,在茶多酚的作用下,乳酸菌的相对丰度高于对照组,而致病菌的相对丰度则低于对照组。综上,适宜浓度(2~4 mg/mL)的茶多酚对植物乳杆菌和致病菌的生长具有双向调节作用,其可增殖植物乳杆菌,同时抑制致病菌。

Enhancing the vitality of probiotics in probiotic product while inhibiting the growth of food-borne pathogenic and spoilage bacteria can improve product quality stability.Under mono-culture and co-culture conditions,the effects of different concentrations of tea polyphenols on the growth of Lactobacillus plantarum,Staphylococcus aureus,and Escherichia coli were comparatively investigated by culture-dependent method and high-throughput sequencing.Mono-culture result showed that with the increase of tea polyphenols concentration,the viable count of L.plantarum first ascended and then decreased,reaching the maximum at the concentration of 2.0 mg/mL.However,the survival rate of the two pathogens decreased continuously,with S.aureus decreasing more significantly.In the co-culture system(S.aureus/E.coli-L.plantarum),the biomass of L.plantarum showed a significant increase with culture time,coupled with a general decrease in the number of the pathogen and pH of the medium.In addition,Illumina Miseq sequencing further showed that the relative abundance of Lactobacillus was higher than that of the control when coexisted with the pathogen in the presence of tea polyphenols,while the relative abundance of the pathogen was lower than that of the control.The results indicated that tea polyphenols at an appropriate concentration(2~4 mg/mL)had a dual-directional regulation on the growth of L.plantarum and pathogens,that was,proliferating L.plantarum while inhibiting the growth of pathogens.