“…For instance, inhibitors of the enzyme methyl coenzyme-M reductase (which is involved in the last step of the methanogenic pathway), such as bromochoromethane (Denman et al, 2007), chloroform (Knight et al, 2011), or 3-nitrooxypropanol (Haisan et al, 2014), did not always result in a reduction of methanogen numbers (Romero-Perez et al, 2014. Other compounds known for their antimicrobial activities were also shown to induce reductions in both MeP and methanogen numbers (Kubo et al, 1993;Iwamoto et al, 2002). Examples of these are nitrates (van Zijderveld et al, 2010;Veneman et al, 2015), anacardic acid contained in cashew nut shell liquid (Shinkai et al, 2012), monensin (Shinkai et al, 2012), and isobutyrate (Wang et al, 2015).…”