预防犊牛腹泻复合微生态制剂3株菌种的配比优化

Optimizing the Ratio of Three Strains of Compound Microecological Preparations for Preventing Calf Diarrhea

试验旨在研究预防犊牛腹泻复合微生态制剂3株菌种的配比优化。通过研究嗜酸乳杆菌、布氏酵母菌、枯草芽孢杆菌不同浓度人工胃液、人工肠液、牛胆盐的耐受性及其对大肠杆菌、沙门氏菌、金黄色葡萄球菌的抑菌性,确定其生物学特性;以大肠杆菌K99为指示菌,研究3种益生菌不同配比对大肠杆菌K99的抑菌效果,以确定其最佳组合。结果表明:(1)3种益生菌在不同pH人工胃培养条件下都具有较好的耐受性,其中嗜酸乳杆菌、芽孢杆菌在pH为5时,存活率达到了118.75%、142.24%,布氏酵母菌对不同pH均表现成活率达到了100%以上。(2)3种益生菌在人工胃液中9 h存活率较高,与0 h的OD600相比,布氏酵母菌、枯草芽孢杆菌、嗜酸乳杆菌存活率分别为108.7%、129.73%、96.37%。(3)在含有不同浓度的牛胆盐培养基中,布氏酵母菌、嗜酸乳杆菌、枯草芽孢杆菌存活率较对照组的存活率最高为60.49%、85.1%、47.42%。(4)3株益生菌按照不同配比在培养12 h后,试验组第2、4、8组较对照组相比差异显著(P<0.05);培养24 h后,试验组第3、4、5、6较对照组差异显著(P<0.05),组间差异不显著(P>0.05);第8个处理组在培养12 h后对大肠杆菌K99的抑菌效果较好。综合分析,3株益生菌对人工胃液、人工肠液、牛胆盐具有较好的耐受性,并具对大肠杆菌K99、沙门氏菌、金黄色葡萄球菌等致病菌均有一定的抑菌特性。嗜酸乳杆菌、枯草芽孢杆菌、布氏酵母菌最佳的优化配比为3:3:1。

The purpose of this study was to optimize the ratio of three strains of compound microecological preparation for prevention of calf diarrhea.The biological characteristics of Lactobacillus acidophilus,Saccharomyces boulardii and Bacillus subtilis were determined by studying the tolerance of artificial gastric juice,artificial intestinal juice and bovine bile salt of different concentrations and their bacteriostasis against Escherichia coli K99,Salmonella and Staphylococcus aureus.The bacteriostasis effects of three probiotics with different proportions on Escherichia coli K99 were studied to determine the optimal combination.The results showed that:(1)the three probiotics had good tolerance under the conditions of different pH value of artificial stomach culture,in which the survival rate of Lactobacillus acidophilus and Bacillus reached 118.75%and 142.24%at pH 5,and the survival rate of Saccharomyces boulardii for different pH value reached more than 100%.(2)The survival rate of three probiotics in artificial gastric juice was higher in 9 hours.Compared with OD 600 in 0 hour,the survival rates of Saccharomyces boulardii,Bacillus subtilis and Lactobacillus acidophilus were 108.7%,129.73%and 96.37%,respectively.(3)In the medium containing different concentrations of bovine bile salt,the survival rate of Saccharomyces boulardii,Lactobacillus acidophilus and Bacillus subtilis was 60.49%,85.1%and 47.42%higher than that of the control group.(4)Three probiotics were cultured in different proportions for 12 hours,and the difference was significant(P<0.05)in experimental group 2,4 and 8 compared with the control group;after 24 hours of culture,the difference was significant(P<0.05)in group 3,4,5 and 6 compared with the control group,and the difference between the groups was not significant(P>0.05);the treatment group 8 had better bacteriostatic effect on E.coli K99 after 12 hours of culture.Comprehensive analysis showed that the three probiotics had good tolerance to artificial gastric juice,artificial intestinal juice and bovine bile salt,and had certain bacteriostatic characteristics against E.coli K99,Salmonella,Staphylococcus aureus and other pathogenic bacteria.The optimal ratio of Lactobacillus acidophilus,Bacillus subtilis and Saccharomyces Brady is 3∶3∶1.