Methane-oxidizing bacteria (methanotrophs) have a ubiquitous distribution in the environment and play an important role in global climate warming by lowering methane emission into the atmosphere. “Terre Calde di Medolla” (literally, “Warm Earths of Medolla”) refers to a farming area, located near the town of Modena (Emilia-Romagna region, northern Italy), which has always been known for the relatively high temperatures of the soil. After the 2012 Emilia earthquake that affected this area, soil temperatures of 44°C were revealed (20–25°C above the local background value) together with diffuse soil fluxes of methane (CH4) and minor, though significant, of carbon dioxide (CO2). Ground heating and gas seepage appeared to be spatially correlated, thus suggesting a close relationship between the two phenomena.The aim of this work was to characterize the methanotrophic microbial community present in soil samples collected from this area using a cultivation-independent approach. We performed clone library analysis and terminal restriction fragment length polymorphism (T-RFLP) fingerprinting of the 16S rDNA and pmoA gene (coding for the alpha-subunit of the particulate methane monooxygenase). Results from 16S rDNA analysis showed that methanotrophic bacteria represented around 10% of the entire microbial community. In particular, bacteria belonging to Acidobacteria and Actinobacteria phyla were detected as well as members of Ammonifex, Sphingomonas and Bacillus genera. Through the analysis of pmoA gene, Methylococcus, Methylocaldum and Methylomonas were found to be the dominant genera (around 90%) of the methanotrophic community under analysis. In addition to these Gammaproteobacteria, Methylocystis spp. were detected which belong to Alphaproteobacteria class. Further studies will define the correlation between the composition and the role of the methanotrophic microbial community and the peculiar characteristics of “Terre Calde di Medolla” soil.
Characterization of methanotrophic microbial community in a soil sample from Terre Calde di Medolla (Italy)
GHEZZI, DANIELE;CAPPELLETTI, MARTINA;FEDI, STEFANO;CAPACCIONI, BRUNO;ZANNONI, DAVIDE
2015
Abstract
Methane-oxidizing bacteria (methanotrophs) have a ubiquitous distribution in the environment and play an important role in global climate warming by lowering methane emission into the atmosphere. “Terre Calde di Medolla” (literally, “Warm Earths of Medolla”) refers to a farming area, located near the town of Modena (Emilia-Romagna region, northern Italy), which has always been known for the relatively high temperatures of the soil. After the 2012 Emilia earthquake that affected this area, soil temperatures of 44°C were revealed (20–25°C above the local background value) together with diffuse soil fluxes of methane (CH4) and minor, though significant, of carbon dioxide (CO2). Ground heating and gas seepage appeared to be spatially correlated, thus suggesting a close relationship between the two phenomena.The aim of this work was to characterize the methanotrophic microbial community present in soil samples collected from this area using a cultivation-independent approach. We performed clone library analysis and terminal restriction fragment length polymorphism (T-RFLP) fingerprinting of the 16S rDNA and pmoA gene (coding for the alpha-subunit of the particulate methane monooxygenase). Results from 16S rDNA analysis showed that methanotrophic bacteria represented around 10% of the entire microbial community. In particular, bacteria belonging to Acidobacteria and Actinobacteria phyla were detected as well as members of Ammonifex, Sphingomonas and Bacillus genera. Through the analysis of pmoA gene, Methylococcus, Methylocaldum and Methylomonas were found to be the dominant genera (around 90%) of the methanotrophic community under analysis. In addition to these Gammaproteobacteria, Methylocystis spp. were detected which belong to Alphaproteobacteria class. Further studies will define the correlation between the composition and the role of the methanotrophic microbial community and the peculiar characteristics of “Terre Calde di Medolla” soil.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
