Eletrossíntese microbiana e caracterização microbiológica do melaço: uma rota sustentável para o sequestro de carbono

Abstract

The increasing emission of carbon dioxide (CO₂) caused by human activities generates serious environmental problems, such as global warming and climate change. This study evaluated the potential of sugarcane molasses as a culture medium for microbial electrosynthesis, targeting CO₂ capture and its conversion into energy-rich organic compounds. Microbiological analyses revealed a diverse microbial community, predominantly composed of Bacillus species, identified morphologically and confirmed at the molecular level through DNA extraction, 16S rRNA gene amplification by PCR, and agarose gel electrophoresis, ensuring the functional compatibility of the isolates with bioelectrochemical processes. Sugarcane molasses efficiently supported bacterial growth, and under the application of electrical current, the microorganisms exhibited increased metabolic activity and CO₂ assimilation. Electrochemical results demonstrated that biocathodes showed a progressive increase in current after inoculation, especially at potentials of -0.8 V and -1 V vs. Ag/AgCl, reaching negative current density peaks of -60 A/m², indicative of reduction reactions. FTIR analyses confirmed the formation of compounds such as acetate, while PCA and Venn diagrams highlighted the functional microbial diversity within the biofilms. The integration of microbiological and electrochemical data reinforces sugarcane molasses as a strategic substrate for bioelectrochemical processes, establishing microbial electrosynthesis as a sustainable approach for carbon capture, bioenergy production, and industrial waste valorization.