title: Microbial analysis in biogas reactors suffering by foaming incidents.
abstract: Foam formation can lead to total failure of digestion process in biogas plants. In the present study, possible correlation between foaming and the presence of specific microorganisms in biogas reactors was elucidated. The microbial ecology of continuous fed digesters overloaded with proteins, lipids and carbohydrates before and after foaming incidents was characterized using 16S rRNA gene sequencing. Moreover, the microbial diversity between the liquid and foaming layer was assessed. A number of genera that are known to produce biosurfactants, contain mycolic acid in their cell wall, or decrease the surface tension of the media, increased their relative abundance after foam formation. Finally, a microorganism similar to widely known foaming bacteria (Nocardia and Desulfotomaculum) was found to increase its relative abundance in all reactors once foam was observed, regardless of the used substrate. These findings suggest that foaming and specific microorganisms might have direct association which requires to be further investigated.
authors: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
authors: Panagiotis G
authors: PG
authors: Kougias
authors: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
authors: Davide
authors: D
authors: De Francisci
authors: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
authors: Laura
authors: L
authors: Treu
authors: Department of Biology, University of Padua, Via U. Bassi 58/b, 35131 Padova, Italy.
authors: Stefano
authors: S
authors: Campanaro
authors: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark. Electronic address: iria@env.dtu.dk.
authors: Irini
authors: I
authors: Angelidaki
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D002417:Cattle; D016000:Cluster Analysis; D005740:Gases / Q000737:chemistry*; D008055:Lipids / Q000032:analysis; D008372:Manure / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D056804:Biofuels; D005740:Gases; D008055:Lipids; D008372:Manure
keywords: Anaerobic digestion; Biogas; Foaming; High throughput sequencing; Microbial community