餐饮垃圾堆肥中蜡样芽孢杆菌的灭活规律

Inactivation Regularity of Bacillus cereus on Composting Waste of Catering Food

摘要: 目的：通过建立处理含有蜡样芽孢杆菌食物垃圾的堆肥，考察堆肥发酵过程中致病芽孢杆菌的灭活情况，评价利用堆肥技术处理含致病芽孢杆菌餐饮垃圾的安全性和可行性。方法：运用牛粪和秸秆建造静态堆肥体系。检测堆制过程中堆体的温度、pH值、含水量；制作混有蜡样芽孢杆菌的食物垃圾样本，在不同堆制时间取样，检测该微生物数量。结果：建造堆体的第2天，温度已超过55℃，并能持续6天；堆体湿度维持在59%~69%，pH值范围在8.5~9.0。平板计数与验证实验显示，堆肥温度下与堆料混合的蜡样芽孢杆菌在第12天被灭活，并且在第40天温度下降后依然检测不到。堆肥中仅承受热压力组蜡样芽孢杆菌在第18日依然存在。结论：本研究结果说明所建立的处理含有蜡样芽孢杆菌的静态堆肥系统能够有效杀灭病原微生物，热压力及堆肥内微生物的及堆料性质共同起到灭活作用。

Abstract: Objective: This thesis focuses on building small-scale processing of domestic waste contained Bacillus cereus biosafety static compost, and exploring the degradation efficiency of Bacillus cereus to evaluate the safety and feasibility of this compost system. Method: Caw manure and straw were used as major material to build a composting system to dispose chicken carcasses. We examined temperature, pH value and moisture to evaluate this system. Result: By using domestic wastes and Bacillus cereus mixture as model, we enumerated Bacillus cereus in both samples in compost piles and in room temperature controls. During the forty-day composting period, the temperature reached 50˚C on second day after composting. It had maintained above 55 for 6 continuous days. The physical and chemical properties, moisture (59% - 69%) and pH (8.5 - 9.0) are suitable for composting. The results of enumeration and certification test shows that, Bacillus cereus mixed with manure in composting condition were inactive within 12 days. Even when the temperature of composting pile dropped below 40˚C, the existence of this pathogen was still negative. In those samples mixed without manure in compost piles, Bacillus cereus survived after 18 days. Conclusion: For Bacillus cereus are fully inactive rapidly, this inexpensive and relatively simple composting system shows its advantage to be a solution of domestic wastes contaminated by Bacillus cereus. The factors of inactivity are the whole condition pressure of composting including heat, the activity of microbes and the change of the character of composting material.