大蒜汁对枯草芽孢杆菌抑制作用的研究

Inhibitory Activity of Garlic Juice to Bacillus subtilis

通过测定菌体浓度、抑菌圈直径和2,6-吡啶二羧酸(DPA)含量,研究大蒜汁对枯草芽孢杆菌(BS)的营养体及芽孢生长、发芽的影响,并采用响应面分析法优化确定大蒜汁抑菌适宜处理条件.结果表明:(1)大蒜汁对BS的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)分别为0.4%和1%;(2)大蒜汁抑制作用主要是延长了BS的生长延缓期,0.3%的大蒜汁可使BS延缓期增加12h;(3)大蒜汁对BS的芽孢和DPA形成有明显的抑制作用,但对芽孢的发芽无抑制作用;(4)加热温度超过35℃、时间大于5h时处理的大蒜汁,对BS的抑制作用明显降低.在pH3～8范围的大蒜汁都有很好的抑菌活性,但pH>8.5时抑菌活性急剧下降;(5)响应面试验分析法优化确立了大蒜汁对BS抑制的二次回归方程和适宜处理条件,即在pH4.5、温度45℃加热处理5h的大蒜汁抑菌效果最好.

To study the inhibitory activity of garlic juice to spore bacteria and develop safe food preservative used garlic. The effect on growth and germination of vegetative and spore of Bacillus subtilis by garlic juice were tested on cell concentration, zone of inhibition and content change of dipicolinic acid （DPA）. The treatment conditions of garlic juice for bacteriostasis were optimized by response surface analysis. The minimum inhibitory concentration （MIC） and the minimum bactericidal concentration （MBC） of garlic juice were 0. 4% and 1%, respectively; garlic juice inhibitory activity mainly delay the lag phase of B. subtilis,0.3% garlic juice can increase 12 h of the lag phase ; garlic juice delayed the formation of spore and DPA, but did not effect the germination of spore. When garlic juice treated more than 35℃ and 5 h,its inhibitory activity on B. subtilis was obviously reduced. Garlic juice have well inhibitory activity in pH 3-8, but the inhibitory activity obviously reduced when pHi8.5. The treatment conditions of garlic juice was optimized by response surface analysis. The result indicated that the best treatment condition of garlic juice for inhibition of B. subtilis was：temperature 45 ℃, time 5 h and pH 4.5.