Steering endogenous ethanol-based chain elongation by biochar amendment in a mixed synergistic fungi-bacteria microbiome: focusing on the role of hydrochar and pyrochar

In this study, the effects of hydrochar and pyrochar from digestate on caproate (C6-MCFA) production in a bacteria-fungi microbiome were systematically compared during complex organic wastewater treatment, which is made of liquified food waste. First, the effect of hydrochar and pyrochar dosage on caproate production was optimized. Then, the analysis of the ethanol production, acidification, CE, and related metabolic parameters (such as pH) provided a deep understanding of the fermentation pathways. The microbial community of fungi and bacteria, functional genes, and CE metabolic pathways with hydrochar and pyrochar amendment were also investigated by the sequencing of 16S rRNA, ITS, and metagenome.