研究玉米秸秆中微生物降解系统的驯化和降解特性

背景。木质纤维素是玉米秸秆中的重要生物资源，但其有效降解带来了挑战。<br>目的。本研究旨在提高木质纤维素的降解速率，以扩大玉米秸秆的效用。<br>方法。使用静态温度限制培养方法在 30°C 下适应能够降解玉米秸秆的微生物系统。<br>结果。在发酵生物降解过程中，有机酸浓度在第 3 天达到峰值，然后逐渐下降。同时，可溶性糖的浓度达到最大值 8.9 μ g ·mL -1 的 mL 值，而总糖含量从 4 mg ·mL -1 至 1.6 mg ·mL -1 在最初的 3 天内，随后稳定下来。糖苷水解酶 （GHs） 和糖基转移酶 （GTs） 作为两个关键酶组出现，分别由 4837 和 1882 个基因组成。值得注意的是，GHs 中的半纤维素酶和纤维素酶家族基因在分解半纤维素和纤维素中起着至关重要的作用。在 GHs 中鉴定出多种木质素纤维素降解酶。在最佳条件下，微生物系统对玉米秸秆的降解效率很高，木质素降解率为 56.83%，纤维素降解率为 39.45%，半纤维素降解率为 32.86%。<br>结论。这些发现进一步促进了玉米秸秆中木质纤维素资源的开发。

Background. Lignocellulose is an important biological resource in corn stover, but its efficient degradation poses challenges.
Objective. This study aims to improve the degradation rate of lignocellulose to expand the utility of corn stover.
Method. A static temperature-restricted culture method was used to acclimate a microbial system capable of degrading corn stover at 30°C.
Result. During the fermentative biodegradation process, the concentration of organic acids peaked on day 3 and then gradually decreased. Meanwhile, the concentration of soluble sugars reached a maximum of 8.9 μg·mL⁻¹, while the total sugar content decreased from 4 mg·mL⁻¹ to 1.6 mg·mL⁻¹ within the first 3 days before stabilizing. Glycoside hydrolases (GHs) and glycosyltransferases (GTs) emerged as two key enzyme groups, consisting of 4837 and 1882 genes respectively. Notably, the hemicellulase and cellulase family genes within GHs play a crucial role in decomposing hemicellulose and cellulose. Multiple lignocellulose-degrading enzymes were identified in GHs. Under optimal conditions, the microbial system exhibited high degradation efficiency against corn stover, with lignin degradation rate reaching 56.83%, cellulose degradation rate 39.45%, and hemicellulose degradation rate 32.86%.
Conclusion. These findings further promote the development of lignocellulose resources in corn stover.