摘要
为探究鼠李糖乳杆菌(Lactobacillus rhamnosus)对河豚毒素(tetrodotoxin,TTX)免疫活性的消减作用方式和可能作用位点,分别采用活化、热灭活和破碎的鼠李糖乳杆菌以及去除胞外多糖、原生质体、细胞壁和肽聚糖的分离样品,与TTX标准品在37℃孵育1 h,使用竞争性酶联免疫吸附法分析作用前后TTX的免疫活性变化。通过化学处理掩蔽鼠李糖乳杆菌表面的羧基和氨基,采用傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)分析菌体表面的化学键振动类型和官能团变化情况。结果发现,活化、热灭活和破碎后的鼠李糖乳杆菌均可消减TTX的免疫活性,因此TTX免疫活性的变化和鼠李糖乳杆菌的活性无关。各分离样品对TTX的消减作用表明肽聚糖成分对TTX免疫活性的消减率最高可达到47%。FTIR分析发现鼠李糖乳杆菌表面羧基掩蔽后可显著降低TTX免疫活性的消减率至18%,而掩蔽氨基则对作用前后的TTX消减率影响无显著差异(P>0.05)。实验表明,消减TTX免疫活性的原因可能为TTX与鼠李糖乳杆菌表面肽聚糖上的羧基结合。
In order to explore the mode and possible sites of action of Lactobacillus rhamnosus in reducing the immunologic activity of tetrodotoxin(TTX),activated cells,heat-inactivated cells,broken cell debris,extracellular polysaccharide-deficient cells,protoplasts,cell walls and cell wall peptidoglycans of L.rhamnosus were separately incubated together with TTX standard at 37℃for 1 h,and the changes in the immunologic activity of TTX before and after the treatment were analyzed by competitive enzyme linked immunosorbent assay(C-ELISA).The carboxyl and amino groups on the surface of L.rhamnosus cells were masked by chemical treatment,and Fourier transform infrared spectroscopy(FTIR)was used to analyze changes in the chemical bond vibration and functional groups on the cell surface.The results showed that activated,thermally inactivated and broken L.rhamnosus cells could reduce the immunologic activity of TTX,indicating no correlation between the cell activity and the changes in the immunologic activity of TTX.Extracellular polysaccharide-deficient cells,protoplasts,cell walls and cell wall peptidoglycans could reduce the immunologic activity of TTX by up to 47%.Masking of carboxyl groups on the cell surface of L.rhamnosus significantly decreased the percentage reduction in the immunologic activity of TTX to 18%,while masking of amino groups had no significant effect(P>0.05).The binding of TTX to carboxyl groups of peptidoglycan in the cell wall of L.rhamnosus probably contributed to the reduction of TTX immunologic activity.
作者
叶精勤
肖叶
阎俊
许长华
汪立平
卢瑛
YE Jingqin;XIAO Ye;YAN Jun;XU Changhua;WANG Liping;LU Ying(Laboratory of Quality and Safety Risk Assessment for Aquatic Product on Storage and Preservation,Ministry of Agriculture and Rural Affairs,Shanghai Aquatic Products Processing and Storage Engineering Technology Research Center,College of Food Sciences and Technology,Shanghai Ocean University,Shanghai 201306,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2021年第14期103-109,共7页
Food Science
基金
上海市科委地方院校能力建设项目(15320502100)。
关键词
河豚毒素
鼠李糖乳杆菌
消减作用
免疫活性
tetrodotoxin
Lactobacillus rhamnosus
reduction
immunologic activity
