Outstanding Enhancement of Caproate production with Microwave Pyrolyzed Highly Reductive Biochar Addition

The integration of biochar into Microbial Chain Elongation (CE) has proven to be an efficient method for generating high-value bio-based products. Our study introduces an innovative application of biochar, manufactured with the aid of microwave irradiation and carbon fiber cloth, into a CE system. Findings emphasize that microwave-produced biochar attained the highest CE efficiency, resulting in a threefold increase compared to systems without biochar. Investigations into the underlying mechanisms suggest that the reductive characteristics of the biochar surface enhance CE performance, concurrently promoting the growth of key bacterial genera such as Parabacteroides, Bacteroides, and Macellibacteroides. Metagenomic analyses further revealed that microwave biochar stimulated an upregulation of functional genes and enzymes vital to the CE process, including those implicated in ethanol oxidation, the reverse beta-oxidation pathway, and fatty acid synthesis. Consequently, this research successfully advanced caproate production through the implementation of a novel microwave biochar preparation technique.