The 4th European Meeting of the International Society for Microbial Electrochemistry and Technology (EU-ISMET 4) focused to highlight the latest breakthroughs in microbial electrochemistry research and applications of bioelectrochemical systems (BES), covering topics from fundamentals to scale-up processes, bioremediation and resource recovery.
Mira Sulonen and Antonella Marone participated and presented their work in the EU-ISMET conference. The oral presentation entitled “Enhancing the bioelectrochemical treatment of acid mine drainage via microbial electrosynthesis” by Mira Sulonen, David Gabriel, Juan A. Baeza and Albert Guisasola discussed the possibility to enhance the treatment of acid mine drainage with combined biological sulfate reduction and microbial electrosynthesis. Acid mine drainage (AMD) is a significant environmental risk due to its high metal content, sulfate content and acidity. Biological treatment of AMD with sulfate reducing bacteria enables simultaneous sulfate removal, metal precipitation as metal sulfides and neutralization. With bioelectrochemical systems, the substrates for sulfate reducing bacteria can be produced on site and microbial electrosynthesis can potentially improve the substrate availability, electrical efficiency and stability of the process.
The poster entitled “Start me up! On the choice of a proper inoculum for treating industrial wastewater” by Antonella Marone, Clement Flayac, Eric Trably, Nicolas Bernet, Juan Antonio Baeza and Albert Guisasola resulted from the join collaboration between GENOCOV and the LBE (Laboratory of Environmental Biotechnology), University of Montpellier, INRA. This work copes with the necessity of establishing an effective syntrophic consortium between fermenters and electroactive bacteria (EAB) to treat real industrial wastewater by Bioelectrochemical Systems. With this objective, the use of sludge from industrial wastewater treatment plant as inoculum was compared with anaerobic sludge from urban wastewater treatment plant, as the most common used inoculum in BES, and with an EAB (Electroactive Bacteria) enriched culture. Different mixtures of the three inocula and the use of the wastewater itself were also evaluated. The results of an in-depth microbial ecology analysis carried-out with the objective of investigating the relationship between the diversity of mixed-species microbial consortia, their electrogenic potential and their effectiveness in treating industrial wastewater in BES, showed the establishement of very complex microbial communities networks. In particular, it was shown that when working with real wastewater in BES the inoculum source has a high impact in shaping microbial community and relative performances, being the sludge from the industrial WWTP the most performant inoculum. Moreover, the microorganisms from wastewater also affect the community structure. Finally, although only few dominant species, both planktonic and of biofilm, were probably responsible for electrochemical performances it was shown that also low abundant species can act as key stone species allowing performance improvement. The resulting new insights provide some guidelines to enhance the selection of effective electricity-driving communities for industrial wastewaters treatment.