Power generation at bioanodes of Pseudomonas aeruginosa for glycerol biotransformation was coupled to the carbon dioxide capture in biocathodes of Chlorella vulgaris in hybrid photosynthetic biofuel cells (HPSBC). Biochemical parameters such as microbial growth, substrate consumption, production of bacterial pigments and CO2 capture were studied. Also electrochemical parameters of maxima current densities (Id max), power output (Pd max) and coulombic efficiencies (C E) were studied. Initially, both systems were evaluated in separate against the corresponding Fe3+|Fe2+ redox pair. In bacterial systems, important results in terms of Id max of 42 ± 2.1 µA cm-2, C E of 48 ± 2.4% and Pd max of 350 ± 17.5 mW cm-2 were achieved. Likewise, for isolated algal cathode systems, Id max of 93 ± 4.65 µA cm-2, C E of 56 ± 2.8% and Pd max of 3.2 ± 0.16 mW cm-2, were achieved. In contrast, when both systems were coupled, a lower Id max of 48.5 ± 2.42 µA cm-2 was observed. Finally, bioelectrochemical conditions were improved based on substrate consumption, electrogenic products, cation transport and mediated electron transfer systems. Thus, higher average values for Id max of 80 ± 4.0 µA cm-2, C E of 71.5 ± 3.57% and Pd max of 650 ± 32.5 mW cm-2 were obtained.
Pseudomonas aeruginosa; Chlorella vulgaris; microbial fuel cells; bioelectrodes; glycerol biotransformation; carbon dioxide capture; electron shuttles
