title: Alteration of bacterial communities and organic matter in microbial fuel cells (MFCs) supplied with soil and organic fertilizer.
abstract: The alteration of the organic matter (OM) and the composition of bacterial community in microbial fuel cells (MFCs) supplied with soil (S) and a composted organic fertilizer (A) was examined at the beginning and at the end of 3 weeks of incubation under current-producing as well as no-current-producing conditions. Denaturing gradient gel electrophoresis revealed a significant alteration of the microbial community structure in MFCs generating electricity as compared with no-current-producing MFCs. The genetic diversity of cultivable bacterial communities was assessed by random amplified polymorphic DNA (RAPD) analysis of 106 bacterial isolates obtained by using both generic and elective media. Sequencing of the 16S rRNA genes of the more representative RAPD groups indicated that over 50.4% of the isolates from MFCs fed with S were Proteobacteria, 25.1% Firmicutes, and 24.5% Actinobacteria, whereas in MFCs supplied with A 100% of the dominant species belonged to γ-Proteobacteria. The chemical analysis performed by fractioning the OM and using thermal analysis showed that the amount of total organic carbon contained in the soluble phase of the electrochemically active chambers significantly decreased as compared to the no-current-producing systems, whereas the OM of the solid phase became more humified and aromatic along with electricity generation, suggesting a significant stimulation of a humification process of the OM. These findings demonstrated that electroactive bacteria are commonly present in aerobic organic substrates such as soil or a fertilizer and that MFCs could represent a powerful tool for exploring the mineralization and humification processes of the soil OM.
authors.affiliation: CRA--Agrobiology and Pedology Research Centre, Piazza D’Azeglio, 30, 50121 Firenze, Italy. stefano.mocali@entecra.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Mocali
authors.forename: Carlo
authors.initials: C
authors.lastname: Galeffi
authors.forename: Elena
authors.initials: E
authors.lastname: Perrin
authors.forename: Alessandro
authors.initials: A
authors.lastname: Florio
authors.forename: Melania
authors.initials: M
authors.lastname: Migliore
authors.forename: Francesco
authors.initials: F
authors.lastname: Canganella
authors.forename: Giovanna
authors.initials: G
authors.lastname: Bianconi
authors.forename: Elena
authors.initials: E
authors.lastname: Di Mattia
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Dell'Abate
authors.forename: Renato
authors.initials: R
authors.lastname: Fani
authors.forename: Anna
authors.initials: A
authors.lastname: Benedetti
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D058448:Biota; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D004560:Electricity; D005308:Fertilizers; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009930:Organic Chemicals / Q000032:analysis*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D017422:Sequence Analysis, DNA; D012987:Soil
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005308:Fertilizers; D009930:Organic Chemicals; D012336:RNA, Ribosomal, 16S; D012987:Soil