Quantitative PCR of pmoA using a novel reverse primer correlates with potential methane oxidation in Finnish fen

We report a new reverse primer (A621r) for use with A189f in PCR amplification of pmoA alleles in type II methanotrophs. The new primer combination was used to successfully amplify pmoA in peat monolith samples of various depths taken from fen-type peatlands in Finland. In quantitative PCR, pmoA amplicons produced from two sets of three replicate monoliths showed a significant Pearson correlation coefficient (r = 0.77 and 0.61) with methane oxidation potential. The maximum methane oxidation potential and number of pmoA amplicons ranged between 8.8-40.5 μmol g (dry weight)−1 d−1 and 5.5 × 107-18.7 × 107 g (wet weight)−1, respectively, occurring in depths between 10 and 30 cm beneath the surface in the seven individual monoliths used in this study.