超高压处理对副溶血性弧菌细胞膜组成成分的影响

Effects of ultra-high pressure on membrane components in Vibrio parahaemolyticus

摘要:

摘要:【目的】探讨水产品中副溶血性弧菌基于细胞膜损伤和修复的耐超高压胁迫机制。【方法】以80－250 MPa超高压多次处理原始敏感菌株，从中筛选分离副溶血弧菌的耐压菌株，通过紫外分光光度法测定超高压处理前后细胞膜通透性的变化;采用SDS-PAGE 电泳技术分析原始敏感菌株与耐高压胁迫菌株细胞膜可溶性蛋白的差异，采用超微量Na + K + ATP 酶试剂盒分别测定原始菌株与耐压菌株的Na + K + ATP 酶活性，用GC-MS 法分析耐压菌株与原始菌株细胞膜脂肪酸组成的差异。【结果】分离获得的副溶血弧菌耐压菌株直接经250 MPa压力胁迫处理，存活量可较原始菌株提高103数量级。当处理压力大于400 MPa时，耐压菌株上清液中核酸物质泄露与原始菌株差异显著。耐压菌的可溶性膜蛋白在分子量为36 kDa 处浓度明显增加，Na + K + ATPase 酶活性比原始菌株提高了83. 3%，细胞膜不饱和脂肪酸含量由51. 57 % 变为54. 23%。【结论】原始的副溶血性弧菌在250 MPa 压力处理后存活率为0. 0008%，而耐高压胁迫菌株在250 MPa 压力处理后存活率可达到0. 28%。经超高压处理分离得到的耐压菌株细胞膜上低分子量可溶性膜蛋白含量高于原始菌株、Na + K + ATPase 酶活性显著高于原始菌株、不饱和脂肪酸比例加大，这些细胞膜上的主要成分含量的变化均与菌株耐压性有关。

Abstract:

Abstract:［Objective］We observed the changes in cell membrane of Vibrio parahaemolyticus which is a prevalent foodborne pathogen by high pressure treatments． ［Methods］Pressure-resistant mutant strains of V． parahaemolyticus were selected with repeated hydrostatic pressures treatment of 80－250MPa from a pressure-sensitive V． parahaemolyticus (ZJGSMC001)．The changes of soluble cell membrane protein，fatty acid profiles and the Na + K + ATPase activity in the pressure-resistant strains and its pressure-sensitive parent strain were determined． ［Results］The pressure-resistant strains had more soluble cell membrane protein of 36 KDa． The Na + K + ATPase of the pressure-resistant strains were 83. 3% more active than the parent strain． The proportion of unsaturated fatty acids in cell membranes was 54. 23% comparing to 51. 57 % (P＜0.05) in the pressure-sensitive strain． ［Conclusion］The pressure-resistant strains may have survived pressure treatments through expressing more low-molecular soluble cell membrane proteins，enhancing the activity of Na+K+ATPase，and increasing the content of unsaturated fatty acids in cell membrane．