Enhancing cellulose and hemicellulose degradation in wheat straw composting by inoculation with Glycomyces: key factors and microbial community dynamics.

Abstract

Actinobacteria are widely used in aerobic composting of straw waste because of their good degradation effect on lignocellulose. However, there are few studies on the degradation effect of Glycomyces on straw. In this study, six laboratory-scale treatments were conducted: corn straw composting with Glycomyces inoculation (CSI), rice straw composting with Glycomyces inoculation (RSI), and wheat straw composting with Glycomyces inoculation (WSI). Additionally, composting control groups were set up for each type of straw without inoculation: corn straw (CS), rice straw (RS), and wheat straw (WS). Subsequently, a series of chemical analyses and enzymological methods were used to assess the effects of Glycomyces inoculation on environmental variables, enzyme activities, and organic components. Also, high-throughput sequencing was employed to explore the microbial community composition that greatly contributed to the degradation rate of cellulose and hemicellulose during the degradation process of wheat straw. Finally, the factors influencing the cellulose and hemicellulose degradation in WSI were identified using structural equation models (SEMs). The results showed that cellulose and hemicellulose degradation rates were higher in the Glycomyces-inoculated treatment groups than in the non-inoculated groups. Importantly, the degradation rates of cellulose and hemicellulose in WSI were the highest, at 68.09% and 66.81%, respectively. Collectively, total nitrogen and the microbial community structure of the top 30 genera contributing to cellulose and hemicellulose degradation were important factors influencing the straw degradation of WSI. This study not only provides new insights into the regulation of wheat straw degradation, but also has great significance for environmental protection.