Anode-associated multispecies exoelectrogenic biofilms are essential for the function of bioelectrochemical systems (BESs). The individual activities of anodeassociated organisms and physiological responses resulting from coculturing are often hard to assess due to the high microbial diversity in these systems. Therefore, we developed a model multispecies biofilm comprising three exoelectrogenic proteobacteria, Shewanella oneidensis, Geobacter sulfurreducens, and Geobacter metallireducens, with the aim to study in detail the biofilm formation dynamics, the interactions between the organisms, and the overall activity of an exoelectrogenic biofilm as a consequence of the applied anode potential. The experiments revealed that the organisms build a stable biofilm on an electrode surface that is rather resilient to changes in the redox potential of the anode. The community operated at maximum electron transfer rates at electrode potentials that were higher than 0.04 V versus a normal hydrogen electrode. Current densities decreased gradually with lower potentials and reached half-maximal values at Ϫ0.08 V. Transcriptomic results point toward a positive interaction among the individual strains. S. oneidensis and G. sulfurreducens upregulated their central metabolisms as a response to cultivation under mixed-species conditions. G. sulfurreducens was detected in the planktonic phase of the bioelectrochemical reactors in mixed-culture experiments but not when it was grown in the absence of the other two organisms.IMPORTANCE In many cases, multispecies communities can convert organic substrates into electric power more efficiently than axenic cultures, a phenomenon that remains unresolved. In this study, we aimed to elucidate the potential mutual effects of multispecies communities in bioelectrochemical systems to understand how microbes interact in the coculture anodic network and to improve the community's conversion efficiency for organic substrates into electrical energy. The results reveal positive interactions that might lead to accelerated electron transfer in mixedspecies anode communities. The observations made within this model biofilm might be applicable to a variety of nonaxenic systems in the field.KEYWORDS bioelectrochemical systems, Shewanella, Geobacter, exoelectrogenic biofilm, transcriptome analysis S everal microorganisms have the ability to transfer respiratory electrons to an extracellular electron acceptor. Extracellular respiration is highly relevant for a number of biogeochemical cycles, because these electron transport chains were developed for reducing metal oxides as well as for nonmembrane-permeable environmental electron shuttles, such as humic substances (1-4). It is likely that the selective pressure to evolve terminal reductases that catalyze electron transfer to solid electron

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The article describes the air purifying device of the “OTPO-9” type, which implements the technology of hydrodynamic purification with a foam method where foam was produced by bubbling. The article considers it as the most environmentally efficient and energy-saving device, based on the results of implementation of the methodology of technology selection for purifying exhaust and effluent gases from toxic components of industrial, public and domestic power units up to 1000 kW developed by the authors. The full-scale laboratory studies of the semi-industrial model of the developed device were carried out by the authors. These studies allowed us to define the nitrogen oxide and sulfur removal efficiency depending on the electric voltage, the shape of the device’s side wall in layout, the submersion of inlet and outlet pipe side holes, the ratio of the anode total area to the cathode one. Moreover, the authors have revealed the device scope of application and its advantages. The article states that the proposed device provides environmental safety of the implementation process in comparison with the use of chemical alkaline solutions, which are dangerous for human health and environment.