盐度对腐败嗜水气单胞菌YCR17腐败特性的影响

Effect of Salinities on Spoilage Characteristics of Aeromonas hydrophila YCR17 Isolated from Spoiled Yellow River Carp

为探究盐度对黄河鲤鱼优势腐败菌Aeromonas hydrophila YCR17腐败特性的影响,在不同浓度NaCl(0,0.5%,1%,2%和3%)下,采用基于紫色杆菌CV026的生物传感器法测定N-Acylhomoserine Lactones(AHLs)的产生,结晶紫染色法测定A.hydrophila YCR17生物膜在96孔板和玻璃介质表面的形成,平板扩散法测定其泳动性,脱脂牛奶法和偶氮酪蛋白法测定其胞外蛋白酶的活性。结果表明,A.hydrophila YCR17菌株AHLs的产生随着NaCl浓度的升高呈现先增高(0~0.5%)后降低(0.5%~0.3%)趋势,在0.5%NaCl下达到最大值。A.hydrophila YCR17形成的生物膜在96孔板和玻璃介质表面表现出一致的变化规律,即在0.5%NaCl时达到最大值,2%和3%的NaCl能够极显著性地抑制生物膜形成(P<0.01),胞外蛋白酶活性也表现出相同的变化趋势。在2%和3%盐浓度下泳动性亦发生明显减弱现象。试验为黄河鲤鱼贮藏、加工过程中的腐败防控提供理论基础。

The present study aimed to evaluate the effect of salinities on the spoilage characteristics of A.hydrophila YCR17 isolated from Yellow River carp.Under different NaCl concentrations(0,0.5%,1%,2%and 3%),AHLs production was detected using biosensor assay with Chromobacterium violaceum 026,biofilms formed on the surface of 96-well plate and glass was tested by crystal violet staining method,swimming motility was measured by plate diffusion assay,besides,extracellular protease activity was detected as well,using skim milk and azocasein methods.The results showed that AHLs produced by A.hydrophila YCR17 was found increased with the rising of NaCl concentrations from 0 to 0.5%,and reduced from 0.5%to 3%.Biofilm formation on 96-well plate and glass reached to the maxmum at 0.5%NaCl,and then begin to decrease,which presented a remarkable inhibition on biofilm formation by high NaCl concentrations.In addition,extracellular protease activity of A.hydrophila YCR17 was also found significantly inhibited(P<0.01)by 2%and 3%NaCl.As for swimming mobility,obvious reduction was obtained at 2%and 3%salinities.A theoretical basis for the prevention of Yellow River carp spoilage during storage and transportation is provided.