Methanotrophic activity of coalbed rocks from "Bogdanka" coal mine (south-cast Poland)

Methane is an atmospheric trace gas, which is estimated to contribute about 20% to global warming. Coal mining used to be regarded as attributing considerably to the anthropogenic emissions of that potent greenhouse gas. Recently discovered methanotrophic abilities of coalbed rocks brought a new argument to the discussion about the environmental impact of the mining industry. In the present work, we determined the methanotrophic activity and maximum capacity (V_max) of methane oxidation originating from rocks surrounding seam 385/2 of the "Bogdanka" coal mine. Methane oxidation rates ranged from 0.231uM CH_4 g day in the rock from the middle of the seam to 0.619 uM CH_4 g day in the bottom rock (4.4 m depth). Methanotrophic activity and VmaJ increased with the distance to the coal body and with decreasing TOC content. Initial and terminal redox conditions (Eh>320 mV, pH 7.60-8.62) confirmed the oxic character of the methane oxidation process.