초록
<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>Microbial electrosynthesis (MES), a process by which microorganisms reduce carbon dioxide to multi‐carbon compounds using electrical current as energy source, has so far been demonstrated at temperatures ranging from 25 °C to 37 °C. Elevated operating temperatures, however, could improve overall performance and product recovery. Here the effect of temperature on MES by the acetogenic thermophiles <I>Moorella thermoacetica</I> and <I>Moorella thermoautotrophica</I> is investigated<I>.</I></P><P><B>RESULTS</B></P><P>Experiments were performed at operating temperatures ranging from 25 °C to 70 °C to determine the optimum operating temperature for MES. Optimal performance was observed to be close to the optimum growth temperatures reported for these strains. Production rate and activation energy of acetate at 60 °C was 6.9 ± 0.6 mM m<SUP>−2</SUP> d<SUP>−1</SUP> and 45.1 ± 3.8 kJ mol<SUP>−1</SUP> for <I>M. thermoacetica</I> and 11.6 ± 0.9 mM m<SUP>−2</SUP> d<SUP>−1</SUP> and 58.9 ± 2.5 kJ mol<SUP>−1</SUP> for <I>M. thermoautotrophica</I> with columbic efficiencies (CE) of 79 ± 15% and 72 ± 4%, respectively.</P><P><B>CONCLUSION</B></P><P>Considering CE and acetate production rate during MES, <I>M. thermoautotrophica</I> outperformed <I>M. thermoacetica</I> over a wide range of operating temperatures. Current‐dependent reduction of CO<SUB>2</SUB> also occurred below the minimum growth temperature of these strains, suggesting that MES is non‐growth associated. © 2016 Society of Chemical Industry</P>