Methane production from the anaerobic digestion of substrates from corn stover: Differences between the stem bark, stem pith, and leaves

This work evaluated the methane potential and methane production rate of the stem bark (SB), stem pith (SP), and leaves (LV) of corn stover from batch anaerobic digestion. The obtained cumulative methane potential and the hydrolysis kinetics constant were 0.201, 0.214, and 0.199 L g^-1 VS (volatile solids) and 0.090, 0.149, and 0.227 d^-1 for SB, SP, and LV, respectively. The chemical composition and the crystalline structure of the substrates as well as their changes during the anaerobic digestion were inspected, and their impacts on the characteristics of methane production were assessed. The methane production rate correlated positively with the hemicellulose and soluble compounds content and negatively with the cellulose and lignin content, but the degradation rates of hemicellulose and cellulose in the specific substrate were complex and comparable. The methane production has limit correlation with the crystalline structure of the substrates. Microbial community structure was analyzed to elucidate functional microorganism contributing to methane production of different substrate. The abundance of Bacteroidetes and Firmicutes was most affected by the substrate, and positively related to methane yields.