In this study we sampled Lake Rotsee, Greifensee, Zug and Lugano to derive general patterns of methane-oxidizing bacteria in proximity to the oxygen-methane interface of these four stratified lakes. We used Illumina amplicon sequencing for the analysis of the 16S rRNA and the 16S rRNA gene as well as pmoA gene and transcripts together with potential methane oxidation rates based on incubations with 13C-CH4.