Ghaly A E, Alkoaik F, Snow A
Biological Engineering Department, Dalhousie University, Halifax, Nova Scotia, Canada B3J 2K9.
Appl Biochem Biotechnol. 2006 Apr;133(1):59-75. doi: 10.1385/abab:133:1:59.
The effectiveness of in-vessel thermophilic composting on the inactivation of Botrytis cinerea was evaluated. The bioreactor operated on an infected mixture of tomato plant residues, wood shavings, and municipal solid compost (1:1.5:0.28). Tap water and urea were added to adjust the moisture content and C:N ratio to 60% and 30:1, respectively. Used cooking oil was added as a bioavailable carbon source to compensate for heat losses from the system and extend the thermophilic composting stage. The controlled thermophilic composting process was successful in inactivating B. cinerea. During all experiments, the average reactor temperature increased gradually, reaching its peak after 31 h of operation. Temperatures in the range of 62.6-63.9 degrees C were maintained during the thermophilic stage by the intermittent addition of used cooking oil. The results of the enzyme-linked immunosorbent assay test indicated that the initial concentration of B. cinerea in the compost samples (14.6 mug of dried mycelium/g of compost) was reduced to 12.9, 8.8, and 2.4 mu/g after 24, 48, and 72 h of thermophilic composting, respectively. Plating assay indicated that the mold was completely inactivated in samples after 48 h of thermophilic composting. No significant reduction in B. cinerea was observed during the transient phase (first 30 h of rising temperature) because the temperature reached the lethal level of 55 degrees C after 23 h, thus allowing only 7 h of exposure to temperatures higher than 55 degrees C during this phase. The relatively short time required for complete inactivation of B. cinerea was achieved by maintaining a constant high temperature and a uniform distribution of temperature and extending the duration of the thermophilic stage by the addition of the proper amount of bioavailable carbon (used cooking oil).
评估了容器内热嗜温堆肥对灰葡萄孢菌灭活的有效性。生物反应器以番茄植株残体、木屑和城市固体堆肥的感染混合物（1:1.5:0.28）运行。添加自来水和尿素将水分含量和碳氮比分别调节至60%和30:1。添加用过的食用油作为生物可利用碳源，以补偿系统的热损失并延长嗜温堆肥阶段。受控的嗜温堆肥过程成功地灭活了灰葡萄孢菌。在所有实验过程中，反应器平均温度逐渐升高，运行31小时后达到峰值。通过间歇性添加用过的食用油，在嗜温阶段维持62.6 - 63.9摄氏度的温度。酶联免疫吸附测定试验结果表明，堆肥样品中灰葡萄孢菌的初始浓度（14.6微克干菌丝体/克堆肥）在嗜温堆肥24、48和72小时后分别降至12.9、8.8和2.4微克/克。平板测定表明，嗜温堆肥48小时后样品中的霉菌被完全灭活。在过渡阶段（温度上升的前30小时）未观察到灰葡萄孢菌有显著减少，因为温度在23小时后达到55摄氏度的致死水平，因此在此阶段仅允许7小时暴露于高于55摄氏度的温度下。通过保持恒定的高温和温度均匀分布，并通过添加适量的生物可利用碳（用过的食用油）延长嗜温阶段的持续时间，实现了灰葡萄孢菌完全灭活所需的相对较短时间。
