Influence of support material properties on the adhesion and growth as a biofilm of a methanogenic consortium
Résumé
In anaerobic wastewater treatment systems, a complex microbial biomass including Archeae and Bacteria must be retained by attachment to solid supports as a biofilm. The aim of this study was to evaluate the impact of support material properties on early microbial adhesion and on colonisation. Seven different substrata (polyethylene, polypropylene, polyvinyl chloride, acrylonitrile butadiene styrene, polycarbonate, borosilicate glass and stainless steel 304L) were described in terms of topography by determining roughness and surface energies . Adhesion of a methanogenic consortium was tested in two hour batch experiments, and colonisation was measured after 15 and 30 days.The quantity of biomass is measured as a percentage of surface covered (after 2 hours) or as dry matter (after 15 and 30 days). The bacterial and archaeal community structures were assessed by molecular fingerprinting profiles (CE-SSCP). The overall adhesion on the tested supports was mostly influenced by the total surface energy. The adhered communities were different from the parent inocula, including the Archaea/Bacteria ratio. This could have a significant impact in the start-up of anaerobic digesters because tendencies observed with short term adhesion are confirmed during establishment of the biofilm after 15 and 30 days.