Acclimation and degradation characteristic of the microbial system in corn straw.

Background: Lignocellulose represents a significant biological resource in corn straw, yet its efficient degradation presents challenges. Purpose: This study aimed to enhance the degradation rate of lignocellulose to expand the utility of corn straw. Methods: A microbial system capable of degrading corn straw was acclimatized at an initial temperature of 30 °C using a static temperature limiting cultivation method. Results: During the biodegradation process via fermentation, the concentration of organic acids peaked on the third day before gradually declining. Concurrently, the concentration of soluble sugars reached a maximum of 8.9 µg mL-1 on the third day, while the total sugar content swiftly reduced from 4 mg mL-1 to 1.6 mg mL-1 within the initial three days and subsequently stabilized. The glycoside hydrolases (GHs) and glycosyl transferases (GTs) emerged as two pivotal enzyme groups, comprising 4,837 and 1,882 genes, respectively. Notably, the hemicellulase and cellulase family genes within the GHs played a crucial role in breaking down hemicellulose and cellulose. A variety of lignocellulose-degrading enzymes were identified among the GHs. Under optimal conditions, the microbial system demonstrated a high efficiency in degrading corn straw, achieving degradation rates of 56.83% for lignin, 39.45% for cellulose, and 32.86% for hemicelluloses. Conclusion: The microbial system domesticated by the restrictive culture method has a good ability to degrade lignocellulose of corn straw, which can further promote the process of corn straw feed.