比较了NaCl含量为2.0％(低盐)和8.0％(高盐)的泡菜在自然发酵过程中pH值、菌落总数、大肠菌群以及乳酸菌数的变化趋势,并对高盐泡菜中的乳酸菌进行了分离鉴定,探讨了不同分离株在蔬菜汁模型中耐NaCl胁迫能力与产酸特性.结果表明,高浓度NaCl对蔬菜自然携带的菌群具有明显抑制作用,高盐泡菜的起始菌落总数、乳酸菌总数、大肠菌群数以及pH下降速度均显著低于低盐泡菜,但发酵144 h后两者均能使产品pH达到3.5 ～3.8,大肠菌群数≤90 MPN/100 g.从高盐泡菜不同发酵阶段的卤水中分离获得1株屎肠球菌(Enterococcus faecium,M0)和4株植物乳杆菌(Lactobacillus plantarum,M1、M3、M4和M6).菌株在0～10％ NaCl蔬菜汁中的生长动力学参数具有显著差异,其中E.faecium M0具有最高的生长速度和耐NaCl胁迫能力.以菌株E.faecium M0和L.plantarum M3按1∶1接种8.0％ NaCl蔬菜汁产酸速度最快,发酵48 h pH值降至3.5,显著低于对照组和其他菌株接种组(P＜0.05).%In this study,the changes of pH,total colony number,lactic acid bacteria and coliform count were determined and compared between pickles containing 2.0％ (low-salt) and 8.0％ (high-salt) of sodium chloride during the process of natural fermentation.The lactic acid bacteria strains isolated and identified from the high-salt pickle were analyzed for their salt tolerance and acid producing ability in the vegetable juice model.Results showed that high concentration of NaCl had inhibitory effect on the natural flora carried by vegetables.The initial total colony number,lactic acid bacteria,coliform and pH drop rate for high-salt pickle were significantly lower than those for lowsalt pickle,however both low-and high-salt pickles reached pH 3.5 ～ 3.8 after 144 h of fermentation with final coliform count ≤ 90 MPN/100g.One strain of Enterococcusfaecium (M0) and 4 strains of Lactobacillus plantarum (M1,M3,M4 and M6) were isolated from high-salt pickle brine.Isolates showed strain-dependant growth kinetic parameters and salt resistance in the vegetable juice model with different NaCl concentration,in which strain M0 showed the best growth characteristics and higher salt resistance.The inoculums with mixture of M0 and M3 by 1∶ 1 proportion in the vegetable juice containing 8.0％ of salt showed the best acidifying ability,with pH value reaching 3.5 after 48 h of fermentation,which was significantly lower than those of control group and the other strains inoculated group (P ＜0.05).
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