平行启动的微生物燃料电池阳极微生物群落差异性解析

Comparison of anodic microbial communities in parallel-operated microbial fuel cells

为揭示平行操作的微生物燃料电池（MFC）产电效能出现差异的原因,应用高通量测序技术对3个平行启动和运行的MFC阳极微生物群落的组成、丰度及多样性进行分析,探讨其差异性与反应器效能的关系.结果表明：表面上控制条件完全一致的平行MFC,其运行状态存在较大差异,反应器Mfc-1和Mfc-3可获得220~240 m V电压及1.85~2.33 W/m3的功率密度;Mfc-2电压一直较低,最高仅为120 m V.同一底物富集的MFC阳极微生物群落组成和丰度差异明显,Mfc-1和Mfc-3中富集了高丰度的有利于产电的微生物种属Anaeromusa、Dechloromonas、Geobacter;Mfc-2则存在较独特的与产电无关的高丰度种属Acinetobacter,这种优势种属的差异最终导致Mfc-2产电效能较差.表面上操作条件相同的平行MFC其阳极微生物优势类群可能存在显著差异,进而决定MFC产电效率的不同.应用MFC探讨其产电效能与影响因子关系时,需运行至少3个平行MFC反应器,以减少潜在的操作失误或缺陷,提高数据可靠性.

The composition, MFCs,which inoculated with abundance and diversity of anodic activated sludge, were investigated microbial communities in three parallel-operated by 16S rDNA based high-throughput sequencing. The relationship between the microbial populations and MFC efficiency was evaluated. The efficiency of MFCs was markedly different even if these MFCs were started up and operated under the same conditions. Two of them （named after Mfc-1 and Mfc-3）arrived at the maximum voltage of 220 to 240 mV with power density of 1.85 to 2.33 W/m3. However, the maximum voltage of MFC Mfc-2 was relative low and kept at about 120 mV. Microbial community composition and abundance were significantly different even if they were enriched by the same substrate. Highly abundant bacteria, such as Anaeromusa,Dechloromonas, Geobacter, that are capable of producing electricity were enriched in Mfc- 1 and Mfc- 3. However, the genus Acinetobacter, a non-electrogen, existed at high abundance in the Mfc-2. This study concluded that divergence of dominant anodic microbial groups in MFCs, due to possible mismanagement and reactor design drawbacks, resulted in the difference of electricity-producing efficiency. To improve the reliability of experimental results during investigating the MFC function and its influencing factors, at least three parallel-operated MFCs were preferred.