Systematic understanding of the potential manganese-adsorption components of a screened Lactobacillus plantarum CCFM436
Systematic understanding of the potential manganese-adsorption components of a screened Lactobacillus plantarum CCFM436
复制标题
DOI：
10.1039/c6ra23877g
复制
发表时间：
2016-10
期刊：
影响因子：
3.9
通讯作者：
Y. Tong;Wang Gang;Qiuxiang Zhang;F. Tian;Xiaoming Liu;Jianxin Zhao;Hao Zhang;Wei Chen
中科院分区：
文献类型：
--
作者：
Y. Tong;Wang Gang;Qiuxiang Zhang;F. Tian;Xiaoming Liu;Jianxin Zhao;Hao Zhang;Wei Chen
锰是一种有毒的重金属，在过量暴露下对人体健康有多种不利影响。在此，我们从34株乳酸菌中筛选出一株对锰具有良好吸附能力的乳酸菌植物乳杆菌CCFM436，从其对锰的结合能力、抗氧化活性和对模拟胃肠道溶液的耐受性等方面进行了研究。植物乳杆菌CCFM436对锰的吸附主要由胞外组分(胞外多糖6.50%~7.22%，细胞壁26.87%~43.90%，壁膜间隙41.48%~47.51%)完成，而只有8.12%~18.40%的锰转移到胞内原生质体中。透射电子显微镜观察表明，随着锰胁迫水平的提高，胞外多糖分泌增多。傅里叶变换红外光谱表明，植物乳杆菌CCFM436的羧基和氨基对吸附能力的贡献最大。高效液相色谱分析表明，富含氨基/羧基的氨基酸(天冬氨酸、谷氨酸、精氨酸和赖氨酸)水平下降，半胱氨酸水平上升，进一步有利于耐受细胞内的锰胁迫。通过聚合酶链式反应-测序鉴定了锰转运子(Mntr)和锰转运子(mnth1/mnt2/mnt3)。此外，qRT-PCR分析证明，mnth1-3是潜在的锰进口体，受MntR负调控。本研究有助于我们对益生菌的健康益处有科学的认识，并为抗锰中毒的食品应用提供了新的潜在参考。
Manganese (Mn) is a toxic heavy metal that has a variety of adverse effects on human health under excess exposure. Here, we screened the lactic acid bacteria Lactobacillus plantarum CCFM436, which displayed a good potential Mn adsorption capacity, from 34 isolates via the Mn binding ability, antioxidative activity and tolerance in simulated gastrointestinal solution. The Mn adsorption of L. plantarum CCFM436 was mainly accomplished by extracellular components (extracellular polysaccharides 6.50–7.22%, cell wall 26.87–43.90%, wall-membrane space, and membrane 41.48–47.51%), whereas only 8.12–18.40% of Mn was transferred into intracellular protoplast. Transmission electron microscope observation indicated that more EPS was secreted with higher levels of Mn stress. Fourier transform infrared spectroscopy showed that the carboxyl and amino groups of L. plantarum CCFM436 made the greatest contribution to the Mn adsorption ability. High performance liquid chromatography analysis indicated that the levels of amino acids (aspartic, glutamic, arginine and lysine) rich in amino/carboxyl groups decreased and cysteine increased, further favorable to tolerance the intracellular Mn stress. The manganese transport operon (mntr) and manganese transporters (mnth1/mnt2/mnt3) were identified by PCR-sequencing. Moreover, qRT-PCR analysis proved that MntH 1–3 were the potential Mn importers and negatively regulated by MntR. This study contributes our scientific understanding of the health-benefits of probiotics and provides a new potential reference in food applications against Mn toxicity.