Fair Friend Institute of Intelligent Manufacturing, Hangzhou Vocational and Technical College, Hangzhou, 310018, China.
Hangzhou Huaxin Mechanical and Electrical Engineering Co., Ltd, Hangzhou, 310030, China.
Sci Rep. 2024 Oct 25;14(1):25364. doi: 10.1038/s41598-024-77136-9.
Anaerobic digestion is one of the most promising options for the disposal of biodegradable food waste. However, the relatively high content of oil in food waste inhibits the conversion efficiency of anaerobic digestion because of the accumulation of long-chain fatty acids (LCFAs). In this study, activated anaerobic sludge was acclimated to accommodate high-oil conditions. The methane yield of high-oil food waste digested by the acclimated sludge increased by 24.9% compared to that digested by the raw sludge. To determine the internal changes in the acclimated sludge, the shifts in the microbial communities during the acclimation period were investigated via high-throughput sequencing (HTS) based on the 16 S rRNA gene. The results indicated that Bacteroidetes, Firmicutes, Chloroflexi and Proteobacteria were the dominant bacteria at the phylum level. The acclimation time allows some functional bacterial taxa to proliferate, such as Clostridium and Longilinea, which are able to degrade LCFAs and turn them into small organic molecules that also have nutrient value for other bacteria. Among the archaeal communities, the hydrogenotrophic methanogen Methanobacterium nearly supplanted the acetotrophic methanogen Methanosaeta. The time profiles of volatile fatty acids (VFAs) and pH during this period provided additional evidence for the success of the acclimation. This study demonstrated the effectiveness of acclimation and the dynamic of microbial communities, which further contributed to the management and resource utilization of high-oil food waste.
厌氧消化是处理可生物降解食物垃圾最有前途的选择之一。然而，食物垃圾中相对较高的油含量会由于长链脂肪酸（LCFAs）的积累而抑制厌氧消化的转化效率。在本研究中，通过驯化活性厌氧污泥来适应高油条件。与原污泥消化相比，驯化污泥消化高油食物垃圾的甲烷产量增加了 24.9%。为了确定驯化污泥的内部变化，通过基于 16S rRNA 基因的高通量测序（HTS）研究了驯化期间微生物群落的变化。结果表明，拟杆菌门、厚壁菌门、绿弯菌门和变形菌门是门水平上的主要细菌。驯化时间允许一些功能细菌类群增殖，例如能够降解 LCFAs 并将其转化为具有营养价值的小分子的梭菌属和长螺旋菌属。在古菌群落中，产氢甲烷菌甲烷杆菌几乎取代了乙酸营养型甲烷菌产甲烷菌。在此期间挥发性脂肪酸（VFAs）和 pH 的时间曲线为驯化的成功提供了额外的证据。本研究证明了驯化的有效性和微生物群落的动态，这进一步有助于高油食物垃圾的管理和资源利用。
