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The purpose of this study was to determine the effect of enrichment procedure on the performance and microbial diversity of an air-cathode microbial fuel cell (MFC) which was explored for simultaneous azo dye decolorization and electricity generation. Two different enrichment procedures in which glucose and Congo red were added into the MFCs sequentially (EP1) or simultaneously (EP2) were tested by operating parallel MFCs independently for more than 6 months. The power density, electrode potential, Congo red decolorization, biofilm morphology, and bacterial diversity of the MFCs under the two enrichment procedures were compared and investigated. The results showed that the enrichment procedures have a negligible effect on the dye decolorization, but significantly affected the electricity generation. More than 90% decolorization at dye concentration of 300 mg/L was achieved within 170 h for the two tested enrichment procedures. However, the MFC with EP2 achieved a maximum power density of 192 mW/m(2), which was 75% higher than that of the MFC with EP1 (110 mW/m(2)). The depressed surfaces of the bacteria in the MFC with EP1 indicated the allergic response caused by the subsequent addition of Congo red. 16S rRNA sequencing analysis demonstrated a phylogenetic diversity in the communities of the anode biofilm and showed clear differences between the anode-attached populations in the MFCs with a different enrichment procedure. This study suggests that the enrichment procedure is important for the MFC explored for simultaneous dye decolorization and electricity generation.

Vertical connections, constructed using inquiry, give students the skills to reach new heights in both their academic and local communities. In this article, the authors present inquiry projects, developed by middle level teachers, to ensure that students use higher-level thinking skills to improve the community. Each project is connected to the previous year's to give students a deeper understanding of how research can help citizens build a sustainable community. Teachers work together to plan field studies and guide students in presenting their findings to others in the community using models, PowerPoint presentations, a web accessible database, and reports from field investigations. The projects are as follows: (1) healthy marine ecosystems--sixth grade; (2) interdisciplinary science: biodiversity and development--seventh grade; and (3) collaborating to create a better biosphere--eighth grade. (Contains 1 figure and 4 online resources.)