好氧－厌氧混合污泥启动微生物燃料电池产电性能及微生物群落动态特征

Electricity generation and dynamics characteristics of microbial community of microbial fuel cells started up with mixture of aerobic/anaerobic sludge

摘要:

摘要:【目的】为探讨好氧－ 厌氧混合污泥启动微生物燃料电池(Microbial fuel cell，MFC)产电性能以及MFC对微生物群落的选择作用，【方法】以乳酸为底物，应用不依赖于培养的微生物分子生物学技术解析单室MFC启动过程中微生物群落的组成和结构动态学特征。【结果】结果表明，MFC经过3个周期启动成功，最高输出电压230 mV。当MFC 外电阻为1656 Ω时，最大功率密度11.15 W/m3，电池运行稳定。混合污泥启动MFC以后，阳极生物膜微生物群落结构同种泥差异较大，且多样性降低。生物膜中微生物类群按丰度依次为β-变形菌纲(Betaproteobacteria) 24.90%、拟杆菌门(Bacteroidetes) 21.30%、厚壁菌门(Firmicutes)9.70%、γ-变形菌纲(Gammaproteobacteria) 8.50%、δ-变形菌纲(Deltaproteobacteria)7.90%、绿弯菌门(Chloroflexi)4.20%以及α-变形菌纲(Alphaproteobacteria) 3.60%。有利于生物膜形成与稳定的动胶菌属(Zoogloea)和不动杆菌属(Acinetobacter)序列丰度分别占生物膜群落的5.00%和3.90%，与MFC产电能力直接相关的地杆菌属(Geobacter)序列由混合污泥中的0.60%上升至阳极生物膜中的2.60%。【结论】本研究表明，MFC阳极生物膜在驯化过程中对污泥中的微生物进行淘汰和选择，最终驯化形成了有利于生物膜形成与稳定、有机物厌氧发酵与产电的微生物菌群。

Abstract:

Abstract:［Objective］To explore electricity generation and dynamic characteristics of microbial community of microbial fuel cells (MFC) started-up with mixed sludge of aerobic/anaerobic sludge.［Methods］ single-chamber MFCs were constructed and characteristics of microbial community composition and structure were investigated by culture-independent microbial molecular techniques.［Results］MFC started up successfully after three cycles’operation，and the maximum output voltage was up to 230 mV．The maximum power density reached 11.15 W/m3． at the outer resistance of 1656 Ω．The structure of microbial community on the anodic biofilm was different from that of seed sludge and microbial diversity reduced．The dominant microbial groups on anodic biofilm were Betaproteobacteria (24.90%)，Bacteroidetes(21.30%)，Firmicutes (9.70%)，Gammaproteobacteria (8.50%)，Deltaproteobacteria (7.90%)，Chloroflexi (4.20%) and Alphaproteobacteria (3.60%)．The biofilm-forming microbial genera Zoogloea and Acinetobacter accounted for 5.00% and 3.90% of total community．The abundance of electricity-producing bacteria Geobacter spp．increased from 0. 60% in mixed sludge to 2.60% on the biofilm.［Conclusion］Dominant microbial populations in mixed sludge were selected by long-term acclimation and finally a beneficial microbial group was built on the anodic biofilm．The populations group was helpful to form a functional and active biofilm，which consequently benefited to produce electricity under anaerobic condition by fermenting organic matter．