Microbial Fuel Cells applied to the metabolically based detection of extraterrestrial life (II): photosynthetic metabolisms

FIGEREDO, FEDERICO; CORTÓN, EDUARDO; ABREVAYA X. C.

Guaruja

Workshop; 2nd Brazilian Workshop on Astrobiology; 2013

Universidad de Sao Paulo

In a previous work (Abrevaya et al., Astrobiology 10: 965-971, 2010) we explored the potential of Microbial Fuel Cells (MFCs) to be used as an in situ life detection method. In particular, we showed that MFCs could allow the detection of microbial life based on metabolism, which is a common signature of life as we know it. We tested that this method allowed the detection of heterotrophic microorganisms from the three domains of life: bacteria, archaea and eukarya. In the present work we test its capability extending the detection towards autotrophic forms of life, specifically testing phototrophic microorganisms of single laboratory cultures. As we previously shown in our previous work, our results indicate that the power and current density values obtained in MFCs using samples containing microorganisms from single cultures or communities are always several orders of magnitude larger than those obtained with samples that does not contain microorganisms or with sterilized samples of the same origin. Moreover, here MFCs are capable to detect a positive light response when measurements of the electric potential in continuum are done. Therefore, our results show that MFCs could be used to detect other metabolisms than the heterotrophic one. In conclusion we demonstrate that MFCs are also being capable to detect photosynthetic metabolism and therefore their corresponding life forms.