Synergistic digestion of banana pseudo-stems with chicken manure to improve methane production: Semi-continuous manipulation and microbial community analysis.

[Display omitted] • A way to efficiently utilize BPS was found by batch and semi-continuous experiments. • AcoD showed synergistic effect, with best result noted with a BPS:CM ratio of 4:1. • The advantage of AcoD over AD is amplified with increasing OLR. • AcoD enhanced the coordination and efficiency among the key digestion bacteria. This study aimed to investigate the interactions between banana pseudo-stems (BPS) and chicken manure (CM) during anaerobic co-digestion (AcoD) in batch and semi-continuous experiments. The batch experiments results showed that the methane yield was the highest (193.7 mL/g VS) in AcoD with BPS: CM ratio of 4:1, which was increased by 57.2% and 66.1%, respectively. Semi-continuous experiments revealed that AcoD resulted in higher methane production. Monitoring of the system parameters indicated that AcoD could better adapt to the increasing organic loading rate, with better system stability and methane production efficiency. The microbial analysis illustrated that AcoD increased the relative abundance of hydrolytic bacteria such as Firmicutes, Patescibacteria, and Bacteroidetes. With regard to archaea, AcoD improved the abundance of Methanosaeta , the major acetoclastic methanogens. These changes in the microbial flora allowed AcoD to remain stable while efficiently producing methane and improved the BPS and CM processing efficiency. [ABSTRACT FROM AUTHOR]