枯草芽孢杆菌 B- 90 3菌株产生的抗菌物质 ,在偏酸性条件下能经受 1 2 1℃ (1 .4Pa/cm2 )高温 2 0分钟 ,仍保持原来的抗菌活性 ;在中性和偏碱性环境中不具备热稳定性。该抗菌物质在p H=4的溶液中 ,半年以上仍保持活性 ;但在碱性条件下 2个月即失活性 ,显示了其酸稳定性。在强酸 p H2～ 3条件下 ,可使有效物质从溶液中沉淀分离出来 ;调高 p H值又可使其重新溶于水中。 Bacillus subtilis B- 90 3 antibacterial substances produced by the strain, under acidic conditions can withstand 121 ℃ (1.4Pa / cm2) high temperature 20 minutes, still maintain the original antibacterial activity; in the neutral and alkaline Environment does not have thermal stability. The antibacterial substance in p H = 4 solution, more than six months remained active; but in alkaline conditions 2 months inactivation, showing its acid stability. In the strong acid p H2 ~ 3 conditions, the effective material can be precipitated from the solution isolated; raise p H value can make it re-dissolved in water.