一株肠源枯草芽孢杆菌的生长、抗逆和产酶特性分析

本试验分析了一株肠源枯草芽孢杆菌生长特性,耐酸、胆盐、高温和重金属性能以及产蛋白酶、淀粉酶的能力。结果表明:菌株最大生长浓度出现在22 h左右。菌株在pH 3.0营养肉汤培养基中培养3 h,存活率为58.6%,培养时间延长至6 h,存活率仍能达到47.5%。在胆盐浓度为0.3%,培养4 h后枯草芽孢杆菌存活率为65.5%,8 h后的存活率仍能达到40.4%。在90℃下,处理10 min成活率为61.8%,处理20 min后仍能达到33.3%。当Cu离子和Zn离子浓度为500 mg/L时,菌株生长量相当于对照的107.6%和86.7%。菌株培养48 h后上清液的淀粉酶活性为1.89 U,蛋白酶活性达到655.2 U。结果表明,本枯草芽孢杆菌具备较好的生长与抗逆特性和较高的酶活力,具备作为益生菌的潜在特质。

Research on Growth Property,Resistance Characteristics and Enzyme Activity of Intestinal Bacillus Subtilis

The study was conducted to evaluate the growth characteristics,acid,bile salt,heat,heavy metal tolerance and protease and amylase activity of intestinal Bacillus subtilis.The result showed that the maximum growth of Bacillus subtilis was present at about 22 h.The survival rate of Bacillus subtilis cultured in pH3.0 medium for 3 h was 58.6%,and for 6 h still was up to 47.5%.The survival rate of Bacillus subtilis cultured in medium with 0.3% bile salt for 4 h was 65.5%,and for 8 h still was up to 40.4%.The survival rate of Bacillus subtilis treated under 90 ℃ for 10 min was 61.8%,and for 20 min still was up to 33.3%.The amount of growth of Bacillus subtilis cultured in medium with 500 mg/L copper or zinc was equivalent to 107.6% and 86.7% of that cultured in the control without heavy metal,respectively.The amylase and protease activity in the culture supernatant of Bacillus subtilis cultured for 48 h reached to 1.89 U and 655.2 U,respectively.The results indicated that the Bacillus subtilis had ideal growth property,resistance characteristics and enzyme activity,and could be used as a probiotic in animal production.