For this purpose, three metabolic genes were selected to detect the inhibition effect of SMX on the homoacetogenesis, methanogenesis and, specifically, acetoclastic methanogenesis pathways; formyltetrahydrofolate synthetase (FTHFS), methyl-coenzyme M reductase (mcrA) and acetyl-coA synthetase (ACAS), respectively. Inhibition effects were determined by an mRNA-based approach.