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

Lang Zhou, Fan Guo, Shiyou Pan, Bing Lu, Liqin Du, Yutuo Wei

State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enzyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China.

Abstract

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.

Keywords: Anaerobic co-digestion, Banana pseudo-stems, Organic loading rate, Semi-continuous.