Thermotrophy Exploratory Study

Abstract

The question of whether environmental heat energy could be utilized as a source ofenergy for biological metabolism is the center of this exploratory research. In 1979, thisauthor postulated a hypothesis for the existence of thermotrophs that could isothermallyutilize environmental heat energy as a source of their energy on Earth. Accordingto this hypothesis, the thermotrophs could be the first primitive forms of life in theearly Earth environment. The chemotrophs and phototrophs that we currently are allwell familiar with might have been evolved somehow from the primitive thermotrophs.Furthermore, all the organisms currently regarded as the “chemotrophs” and “phototrophs”could actually be the mixed trophy types containing thermotrophic features: thermo-chemotrophs and thermo-phototrophs. Energetic analysis with the thermodynamicfirst law indicated that the anaerobic acetate-utilizing methanogenic archaea Methanosarcinacould be a “living fossil specimen” of the thermotrophs. Experiments with enrichedacetate-utilizing methanogen, including Methanosarcina, has, for the first time,demonstrated that their anaerobic metabolism was indeed associated with isothermalenvironmental heat utilization, resulting in their liquid culture temperature to change(decrease) by about −0.10 oC and sometimes drop by as much as −0.45 oC observed inthe experiments. The mean temperature change (drop) was −0.25 ±0.06 oC.