近日，广东工业大学环境健康与污染控制研究院、环境科学与工程学院安太成教授团队在食品垃圾发酵过程中挥发性有机物的释放和微生物菌群结构变化及二者之间的相互影响方面取得最新进展，研究成果以《Odorous VOCs released from bio-decomposition and its interaction mechanism with bacteria: Compared inter-type with intra-type household garbage》为题发表在Journal of Cleaner Production （https://doi.org/10.1016/j.jclepro.2024.141523；2024，447：141523）上。论文的第一作者为梁志梳副教授，通讯作者为李桂英教授。该研究通过构建垃圾发酵反应器模拟6种食品垃圾发酵过程，阐明发酵过程中挥发性有机物(VOCs)的释放特征和微生物的演变规律，探究了不同种类食品垃圾之间的差异，揭示了释放VOCs与微生物在发酵过程中的相互作用机制。这些结果可以为食品垃圾处理过程中VOCs的控制提供技术指导。

 

食品垃圾在微生物发酵过程中产生的挥发性有机物（VOCs）和致病菌会造成恶臭和健康风险。因此，本研究在实验室中利用自制反应器进行了为期90天的发酵实验，比较6种种内和种间食品垃圾发酵过程中VOCs和发酵菌群的演变特征及其相互作用机制。结果表明：除鱼肉垃圾外，其他垃圾发酵产生的VOCs的排放通量均在第十天达到顶峰然后快速地下降直到趋于平稳。对于蔬菜垃圾而言，西洋菜比辣椒和洋葱垃圾释放出了更高浓度（2.5×10⁴−2.4×10⁶ μg/m³）和更大通量（5.4−508 μg•kg^-1·h^-1）的VOCs。在肉类垃圾中，鱼肉释放的VOCs（1.4×10⁵−8.4×10⁶ μg/m³ and 68.4−4.3×10³ μg•kg^-1•h^-1）多于猪肉和鸡肉垃圾。蔬菜垃圾释放的主要含硫类挥发性有机物和含氧类挥发性有机物为二甲基三硫醚（DMTS）与乙酸乙酯。肉类垃圾释放的主要含硫类挥发性有机物和含氧类挥发性有机物为DMTS与甲基丙烯酸甲酯。渗滤液的臭味主要来自于它释放出的含硫类化合物。主要的发酵菌群在种内垃圾间高度相似，但是在种间呈现出了明显的差异，乳杆菌（Lactobacillus）和丛毛单胞菌（Comamonas）以及嗜胨菌（Peptoniphilus）和污虫蝇单胞菌（Wohlfahrtiimonas）分别为蔬菜和肉类垃圾中的主要发酵菌群。发酵微生物与乙酸乙酯、DMDS和2-丁酮之间存在显著相关性。原核生物功能预测（FAPROTAX）表明：乳杆菌属（Lactobacillus）和杆菌属（Bacteroides）分别与含硫化合物转化和碳氢化合物的降解有关，即微生物群落在食品释放VOCs中具有重要的贡献。食品垃圾中的致病菌主要是肠球菌（Enterococcus）、变形菌（Proteobacteria）、分枝杆菌（Mycobacterium）和沙门菌（Salmonella）。因此，我们的研究结果将非常有助于相关部门制定垃圾处置对策减少发酵过程中排放VOCs。

 

论文网址：https://doi.org/10.1016/j.jclepro.2024.141523

 

图表摘要：

英文摘要：

Volatile organic compounds (VOCs) and pathogens that are generated during fermentation of food waste by microorganisms have caused odor annoyance and health risks. In this work, the evolution profiles of them during aerobic decomposition of inter-type and intra-type food waste were compared in laboratory-controlled reactors for three months. The emission fluxes of VOCs reached peak on the 10th day (except fish waste), then decreased sharply until leveled off. For vegetable waste, watercress emitted higher concentrations (2.5×10⁴−2.4×10⁶ μg/m³) and emission fluxes of VOCs (5.4−508 μg•kg^-1·h^-1) than pepper and onion. While for meat waste, the emitted VOCs from fish (1.4×10⁵−8.4×10⁶ μg/m³ and 68.4−4.3×10³ μg•kg^-1•h^-1) were higher than chicken and pork. Dimethyl trisulfide (DMTS) and ethyl acetate as well as DMTS and methyl methacrylate were dominant oxygenated VOCs and volatile organic sulfur compounds in vegetable and meat wastes, respectively. The odor from the leachate was attributed to the emitted sulfur-containing compounds. The main fermented bacteria in intra-type food waste were highly similar, but differed greatly between the inter-type food waste with Lactobacillus and Comamonas as well as Peptoniphilus and Wohlfahrtiimonas as the major fermented bacteria in vegetable and meat wastes, respectively. Significant correlations between microbial community and VOCs including ethyl acetate, DMDS and 2-butanone were observed. As predicted by functional annotation of prokaryotic taxa (FAPROTAX), Lactobacillus and Bacteroides were correlated with the respiration of sulfur-containing compounds and hydrocarbon degradation, respectively, suggesting that production of VOCs was contributed mainly by bacteria communities. Pathogenicity of food waste was mainly due to Enterococcus, Proteobacteria, Mycobacterium, and Salmonella. Our results are conductive to develop countermeasures to reduce VOC emission during food waste decomposition.

 

资助项目：本研究受到国家自然科学基金（U1901210, 42177410, 42130611），广州市基础与应用基础研究（202201010689），粤港澳污染物暴露与健康联合实验室（2020B1212030008）的资助。