Volcanic and geothermal systems emit endoge-nous gases by widespread degassing from soils, including CH 4 , a greenhouse gas twenty-five times as potent as CO 2 . Recently, it has been demonstrated that volcanic or geother-mal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to con-sume 10–40 Tg of CH 4 a −1 and to trap more than 50 % of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emis-sion was previously estimated at about 2.5 Mg a −1 (t a −1). Laboratory incubation experiments with three top-soil sam-ples from Favara Grande indicated methane consumption values of up to 59.2 nmol g −1 soil d.w. h −1 . One of the three sites, FAV2, where the highest oxidation rate was de-tected, was further analysed on a vertical soil profile, the maximum methane consumption was measured in the top-soil layer, and values greater than 6.23 nmol g −1 h −1 were still detected up to a depth of 13 cm. The highest con-sumption rate was measured at 37 • C, but a still detectable consumption at 80 • C (> 1.25 nmol g −1 h −1) was recorded. The soil total DNA extracted from the three samples was probed by Polymerase Chain Reaction (PCR) using stan-dard proteobacterial primers and newly designed verrucomi-crobial primers, targeting the unique methane monooxyge-nase gene pmoA; the presence of methanotrophs was detected at sites FAV2 and FAV3, but not at FAV1, where harsher chemical–physical conditions and negligible methane oxi-dation were detected. The pmoA gene libraries from the most active site (FAV2) pointed to a high diversity of gammaproteobacterial methanotrophs, distantly related to Methylocaldum-Metylococcus genera, and the presence of the newly discovered acido-thermophilic Verrucomicrobia methanotrophs. Alphaproteobacteria of the genus Methy-locystis were isolated from enrichment cultures under a methane-containing atmosphere at 37 • C. The isolates grow at a pH range of 3.5 to 8 and temperatures of 18–45 • C, and consume 160 nmol of CH 4 h −1 mL −1 of culture. Soils from Favara Grande showed the largest diversity of methan-otrophic bacteria detected until now in a geothermal soil. While methanotrophic Verrucomicrobia are reported as dom-inating highly acidic geothermal sites, our results suggest that slightly acidic soils, in high-enthalpy geothermal sys-tems, host a more diverse group of both culturable and un-cultivated methanotrophs.