<P><B>Abstract</B></P> <P>Trace element (TE) requirements of <I>Methanothermobacter okinawensis</I> and <I>Methanothermobacter marburgensis</I> were examined <I>in silico</I>, and using closed batch and fed-batch cultivation experiments. <I>In silico</I> analysis revealed genomic differences among the transport systems and enzymes related to the archaeal Wood-Ljungdahl pathway of these two methanogens. <I>M. okinawensis</I> responded to rising concentrations of TE by increasing specific growth rate (µ) and volumetric productivity (MER) during closed batch cultivation, and can grow and produce methane (CH<SUB>4</SUB>) during fed-batch cultivation. <I>M. marburgensis</I> showed higher µ and MER during fed-batch cultivation and was therefore prioritized for subsequent optimization of CO<SUB>2</SUB>-based biological CH<SUB>4</SUB> production. Multiple-parameter cultivation dependency on growth and productivity of <I>M. marburgensis</I> was finally examined using exponential fed-batch cultivation at different medium-, TE- and sulphide dilution rates, and different gas inflow rates. MER of 476mmolL<SUP>−1</SUP> h<SUP>−1</SUP> and µ of 0.69h<SUP>−1</SUP> were eventually obtained during exponential fed-batch cultivations employing <I>M. marburgensis.</I> </P> <P><B>Highlights</B></P> <P> <UL> <LI> The physiological role of trace elements was examined. </LI> <LI> <I>M. okinawensis</I> was grown in fed-batch cultivation mode. </LI> <LI> Exponential fed-batch cultivation was performed by employing <I>M. marburgensis</I>. </LI> <LI> The importance of a TE feeding strategy to achieve high MER is shown. </LI> <LI> A specific growth rate of 0.69h<SUP>−1</SUP> was obtained for <I>M. marburgensis.</I> </LI> </UL> </P>