几株有益芽孢杆菌对温度、制粒工艺及pH值的耐受性

Endurance of Temperature,Processing Procedure and pH by Several Strains of Useful Bacillus

报道了实验室分离、筛选的 5株有益芽孢杆菌对温度、对虾饲料制粒工艺流程和pH值的耐受性。结果表明 ,5株芽孢杆菌经 80℃水浴 4 0min后全部存活 ,90℃水浴 2 0min有 35 %～ 70 %存活 ,10 0℃水浴 10min仍有 30 %～ 5 0 %存活 ,显示所筛选的 5株芽孢杆菌对高温有较强的耐受力 ;在对虾饲料中添加 5株芽孢杆菌 ,经整个生产工艺流程后芽孢杆菌存活 95 %,烘干后芽孢杆菌存活 93%,说明杆菌能够承受饲料制粒生产中压力、温度和水分的变化 ;当pH值为 3.8、4 .6、5 .2时 ,分别有 1、3、5株菌能繁殖 ,pH值 6 .0～ 8.5时 ,5株菌生长旺盛 ,将 5株菌经pH值 2 .2～ 4 .6处理1h ,再接种在pH值 7.2的培养基可以良好生长 ,说明杆菌在酸性环境中生长性能较差 ,在弱酸性和碱性环境中生长旺盛 ;能耐受酸性环境而存活 ,再给予适宜环境即能良好生长。 5株芽孢杆菌具有作为水产硬颗粒饲料专用益生素菌株的优势。

The endurance of temperature, processing procedure and pH by 5 strains of isolated Bacillus was studied. All bacilli could survive for 40 min in water at 80℃, 35%-70% of those could survive at 90 ℃ for 20 min ; 30%-50% could survive at 100 ℃ for 10 min. The result indicated that the bacillus could bear high temperature. 95% of the bacillus added to the shrimp feedstuff survived after the processing; 93% survived after being dried. When pH of culture medium is 3.8, 4.6 and 5.2,one, three and five strains bacillus can reproduce respectively, furthermore, these bacilli grew well with pH=6.0-8 5,During pH=2.2-4.6 for one hour, they were inoculated (pH=7.2) and grew well. The results showed that all strains can endure high temperature, the change of temperature, pressure and water during the processing. 5 strains of bacillus grew better with the basic environment of low acid than with weak acid environment. These bacilli had such advantages as live-probiotics.