title: Diversity of Methane-Oxidizing Bacteria in Soils from "Hot Lands of Medolla" (Italy) Featured by Anomalous High-Temperatures and Biogenic CO2Emission.
abstract: "Terre Calde di Medolla" (TCM) (literally, "Hot Lands of Medolla") refers to a farming area in Italy with anomalously high temperatures and diffuse emissions of biogenic CO2, which has been linked to CH4oxidation processes from a depth of 0.7 m to the surface. We herein assessed the composition of the total bacterial community and diversity of methane-oxidizing bacteria (MOB) in soil samples collected at a depth at which the peak temperature was detected (0.6 m). Cultivation-independent methods were used, such as: i) a clone library analysis of the 16S rRNA gene and pmoA (coding for the α-subunit of the particulate methane monooxygenase) gene, and ii) Terminal Restriction Fragment Length Polymorphism (T-RFLP) fingerprinting. The 16S rRNA gene analysis assessed the predominance of Actinobacteria, Acidobacteria, Proteobacteria, and Bacillus in TCM samples collected at a depth of 0.6 m along with the presence of methanotrophs (Methylocaldum and Methylobacter) and methylotrophs (Methylobacillus). The phylogenetic analysis of pmoA sequences showed the presence of MOB affiliated with Methylomonas, Methylocystis, Methylococcus, and Methylocaldum in addition to as yet uncultivated and uncharacterized methanotrophs. Jaccard's analysis of T-RFLP profiles at different ground depths revealed a similar MOB composition in soil samples at depths of 0.6 m and 0.7 m, while this similarity was weaker between these samples and those taken at a depth of 2.5 m, in which the genus Methylocaldum was absent. These results correlate the anomalously high temperatures of the farming area of "Terre Calde di Medolla" with the presence of microbial methane-oxidizing bacteria.
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna.
authors.forename: Martina
authors.initials: M
authors.lastname: Cappelletti
authors.forename: Daniele
authors.initials: D
authors.lastname: Ghezzi
authors.forename: Davide
authors.initials: D
authors.lastname: Zannoni
authors.forename: Bruno
authors.initials: B
authors.lastname: Capaccioni
authors.forename: Stefano
authors.initials: S
authors.lastname: Fedi
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics*; D058448:Biota; D002245:Carbon Dioxide; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D007558:Italy; D008697:Methane / Q000378:metabolism*; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000235:genetics; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D002245:Carbon Dioxide; D010105:Oxygenases; C021555:methane monooxygenase; D008697:Methane