应用菌落免疫印迹技术测定多菌株发酵乳中鼠李糖乳杆菌生长与存活特征

Application of the colony immunoblotting technique for characterizing Lactobacillus rhamnose growth and survival in multiple-strain fermented milk

应用菌毛蛋白多克隆抗体建立了鼠李糖乳杆菌特异性菌落免疫印迹检测方法,并结合常规的MRS平板计数对鼠李糖乳杆菌grx19在多菌株发酵牛乳中的生长与存活特征进行了研究。结果表明：建立的菌落免疫印迹法能够对鼠李糖乳杆菌进行选择性计数。鼠李糖乳杆菌grx19与常规酸奶发酵菌保加利亚乳杆菌LB和嗜热链球菌ST在42℃混合发酵中,grx19活菌增殖速度显著低于LB和ST（P〈0.01）,低接种量的grx19（106~107m L-1）对LB和ST增殖及产酸没有显著影响,但高接种量grx19（7×107m L-1）在发酵后期对LB和ST生长产生一定抑制作用。在4℃冷藏过程中,grx19呈缓慢下降趋势,第28 d存活率保持在30%~32%,显著高于LB和ST（7%~16%）,结果表明grx19具有较强的耐低温冷藏能力。

The specific colony immunoblotting（CIB） technique for Lactobacillus rhamnose was developed using polyclonal antibody against pi- li subunit, and the growth and survival characterization ofa Lactobacillus rhamnose strain grx19 in the multiple-strain fermented milk was deter- mined using CIB combined with MRS plating counting. The results showed that the CIB technique can be used for the selective counting Lactobacillus rhamnose strain. During the mixed fermentation with yoghurt starter culture L. bulgaricus （LB） and S.thermophilus （ST） at 42 ℃, the total number of strain grx19 slightly raised, which significantly slower than those of LB and ST （P〈0.01）. No siginificant inhibition effects on LB and ST growth and acid producing were observed during the mixed fermentation with lower inoculum （106-107 mL-1） of grx19. However, the growth of LB and ST were slightly inhibited in the late fermentation when co-culture with high inoculum of grx19 （7 × 107 mL-1）. During cold storage at 4 ℃, the number of viable grx19 decreased slowly, and the survival rate at 28 d were kept at 30% to 32%,which were significantly higher than those of LB and ST （7% - 16%）. The results showed that grx19 had higher survival viability during cold storage.