Zamanzadeh Mirzaman, Hagen Live Heldal, Svensson Kine, Linjordet Roar, Horn Svein Jarle
Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P. O. Box 5003, N-1432, Ås, Norway.
Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, P.O. Box 14155-6446, Tehran, Iran.
Sci Rep. 2017 Dec 15;7(1):17664. doi: 10.1038/s41598-017-15784-w.
In this work, performance and microbial structure of a digestion (food waste-only) and a co-digestion process (mixture of cow manure and food waste) were studied at mesophilic (37 °C) and thermophilic (55 °C) temperatures. The highest methane yield (480 mL/g VS) was observed in the mesophilic digester (MDi) fed with food waste alone. The mesophilic co-digestion of food waste and manure (McoDi) yielded 26% more methane than the sum of individual digestions of manure and food waste. The main volatile fatty acid (VFA) in the mesophilic systems was acetate, averaging 93 and 172 mg/L for McoDi and MDi, respectively. Acetate (2150 mg/L) and propionate (833 mg/L) were the main VFAs in the thermophilic digester (TDi), while propionate (163 mg/L) was the major VFA in the thermophilic co-digester (TcoDi). The dominant bacteria in MDi was Chloroflexi (54%), while Firmicutes was dominant in McoDi (60%). For the mesophilic reactors, the dominant archaea was Methanosaeta in MDi, while Methanobacterium and Methanosaeta had similar abundance in McoDi. In the thermophilic systems, the dominant bacteria were Thermotogae, Firmicutes and Synergistetes in both digesters, however, the relative abundance of these phyla were different. For archaea, the genus Methanothermobacter were entirely dominant in both TDi and TcoDi.
在这项研究中,研究了中温(37°C)和高温(55°C)条件下单一消化(仅食物垃圾)和共消化过程(牛粪与食物垃圾混合物)的性能及微生物结构。在仅投喂食物垃圾的中温消化器(MDi)中观察到最高的甲烷产量(480 mL/g VS)。食物垃圾与牛粪的中温共消化(McoDi)产生的甲烷比牛粪和食物垃圾单独消化产生的甲烷总量多26%。中温系统中的主要挥发性脂肪酸(VFA)是乙酸盐,McoDi和MDi中的平均浓度分别为93和172 mg/L。乙酸盐(2150 mg/L)和丙酸盐(833 mg/L)是高温消化器(TDi)中的主要VFA,而丙酸盐(163 mg/L)是高温共消化器(TcoDi)中的主要VFA。MDi中的优势细菌是绿弯菌门(54%),而厚壁菌门在McoDi中占主导地位(60%)。对于中温反应器,MDi中的优势古菌是甲烷八叠球菌属,而甲烷杆菌属和甲烷八叠球菌属在McoDi中的丰度相似。在高温系统中,两个消化器中的优势细菌都是栖热袍菌门、厚壁菌门和互养菌门,然而,这些菌门的相对丰度不同。对于古菌,嗜热栖热甲烷杆菌属在TDi和TcoDi中均完全占主导地位。