Transcriptomic analysis of Methanothermobacter marburgensis under different nickel concentrations.

This project investigates the transcriptomic response of the hydrogenotrophic methanogen Methanothermobacter marburgensis under different nickel concentrations. Under strictly nickel-limited conditions , two cytosolic [NiFe]-hydrogenases, F420-reducing hydrogenase and heterodisulfide reductase-associating hydrogenase are strongly down-regulated, in which a coupled reaction of [Fe]-hydrogenase (Hmd) with F420-reducing methylene-tetrahydromethanopterin dehydrogenase (Mtd) substitutes the function of Frh, and F420-electron donating protein complexes with Hdr and donates electrons from the reduced form of F420 to Hdr. Using RNA sequencing, we analyzed gene expression changes to better understand the regulation of methanogenesis and the essential role of Hmd under nickel limitation.