Performance evaluation and bacteria analysis of AFB-MFC enriched with high-strength synthetic wastewater

In order to study the performance and bacterial communities of an anaerobic fluidized bed microbial fuel cell (AFB-MFC) system, the 16S rDNA gene sequencing was applied, and high-strength synthetic wastewater was treated by the AFB-MFC system. The high-strength synthetic wastewater, in which the concentrations of chemical oxygen demand (COD), nitrite nitrogen, and nitrate nitrogen were above 19,000, 2,516–3,871 and 927–1,427 mg/L, was treated by the AFB-MFC system. The removal efficiency of COD, nitrite nitrogen, and nitrate nitrogen reached 70–89, 98 and 98%, while the maximum voltage was 394 mV. The bacteria analysis revealed the presence of Alistipes putredinis, Carnobacterium sp., Victivallis vadensis, Klebsiella pneumoniae, Thauera sp., Parabacteroides merdae, Parvimonas micra, Parabacteroides sp., and Desulfomicrobium baculatum in the anode chamber. In addition, the Klebsiella pneumoniae was observed to have the capability of organic degradation and electricity generation, while the Thauera sp. has the capability of denitrification.

Detection of WWE2-relatedLentisphaeraeby 16S rRNA gene sequencing and fluorescence in situ hybridization in landfill leachate

We collected samples of anaerobic landfill leachate from municipal solid waste landfill (Vert-le-Grand, France) and constructed 16S rRNA clone libraries using primers targeting Planctomycetes and relatives (Pla46F and 1390R). Analyses of 16S rRNA gene sequences resulted in the abundant representation of WWE2-related Lentisphaerae, members of the phylum Lentisphaerae, in the clone library (98% of the retrieved sequences). Although the sequences that are phylogenetically affiliated with the cultured isolate Victivallis vadensis were identified (WWE2 subgroup II), the majority of the sequences were affiliated with an uncultured Lentisphaerae lineage (WWE2 subgroup I). We designed oligonucleotides probes targeting the specific 16S rRNA gene regions of those 2 subgroups. Fluorescence in situ hybridization confirmed the abundance of the uncultivated WWE2 subgroup I in our leachate samples.