Supplementary material from "Electrical output of bryophyte microbial fuel cell systems is sufficient to power a radio or an environmental sensor"

Plant microbial fuel cells are a recently developed technology that exploits photosynthesis in vascular plants by harnessing solar energy and generating electrical power. In this study, the model moss species <i>Physcomitrella patens</i>, and other environmental samples of mosses, have been used to develop a non-vascular bryophyte microbial fuel cell (bryoMFC). A novel three-dimensional anodic matrix was successfully created and characterized and was further tested in a bryoMFC to determine the capacity of mosses to generate electrical power. The importance of anodophilic microorganisms in the bryoMFC was also determined. It was found that the non-sterile bryoMFCs operated with <i>P. patens</i> delivered over an order of magnitude higher peak power output (2.6 ± 0.6 µW m<sup>-2</sup>) than bryoMFCs kept in near-sterile conditions (0.2 ± 0.1 µW m<sup>-2</sup>). These results confirm the importance of the microbial populations for delivering electrons to the anode in a bryoMFC. When the bryoMFCs were operated with environmental samples of moss (non-sterile) the peak power output reached 6.7 ± 0.6 mW m<sup>-2</sup>. The bryoMFCs operated with environmental samples of moss were able to power a commercial radio receiver or an environmental sensor (LCD desktop weather station).