Composition and role of the attached and planktonic microbial communities in mesophilic and thermophilic xylose-fed microbial fuel cells.

A mesophilic (37 °C) and a thermophilic (55 °C) two-chamber microbial fuel cell (MFC) were studied and compared for their power production from xylose and the microbial communities involved. The anode-attached, membrane-attached, and planktonic microbial communities, and their respective active subpopulations, were determined by next generation sequencing (Illumina MiSeq), based on the presence and expression of the 16S rRNA gene. accounted for 65% of the anode-attached active microbial community in the mesophilic MFC, and were associated to electricity generation likely through direct electron transfer, resulting in the highest power production of 1.

High-rate ferric sulfate generation by a Leptospirillum ferriphilum-dominated biofilm and the role of jarosite in biomass retention in a fluidized-bed reactor.

The aims of this work were to develop a high-rate fluidized-bed bioprocess for ferric sulfate production, to characterize biomass retention, and to determine the phylogeny of the enrichment culture. After 7 months of continuous enrichment and air aeration at 37 degrees C, the iron oxidation rate of 8.2 g Fe(2+) L(-1)h(-1) (4.