Microbial community in the anodic biofilms on a bioelectrochemical system-based trickling filter reactor

The bacterial community structures of the biofilms adhering to the anodes of the two reactors were analyzed by amplifying the 16S rRNA genes of the microbial assemblage using the Illumina high throughput sequencing system. Total 18 samples was extracted. Bacteria obtained in the precipitate of the wastewater in the BES-TF reactor were considered to be samples of the planktonic cell (PC) fraction. The upper and lower anodes were scraped using disinfected spoons, and the biofilm samples obtained were considered as the outer biofilm from the upper (Up-Upper part-Outer; Up-Lower part-Outer) and lower (Low-Outer) anodes. The biofilms in the middle were also extracted from the upper (Up-Upper part-Middle; Up-Lower part-Middle) anodes. The part of the biofilm adhering tightly to the anodes were now considered as the inner layers of the upper (Up-Upper part-Inner; Up-Lower part-Inner) and lower (Inner-Low) anodes.