Bao Chengling, Liu Zhiyun, Zhong Xiaoxia, Guan Xiaofeng, Cao Yunhe, Huang Jinxiu
National Center of Technology Innovation for Pigs, Chongqing 402460, China.
Chongqing Academy of Animal Science, Chongqing 402460, China.
Int J Mol Sci. 2025 May 14;26(10):4702. doi: 10.3390/ijms26104702.
The efficient degradation of lignocellulose is essential for valorizing agricultural waste and reducing environmental pollution. An efficient degradation process requires an enzyme cocktail capable of comprehensively deconstructing lignocellulosic components. In this study, the secretome of Mafic-2001 induced by rice straw was examined, and the enzymatic composition and reaction conditions of were optimized. Mafic-2001 secreted an enzyme cocktail that included ligninolytic enzymes, cellulases, and hemicellulases. However, the relative abundances of endoglucanase (EG) and β-glucosidase (βG) were only 64.37% and 10.69%, respectively, compared with the relative abundance of cellobiohydrolase, which indicated a critical bottleneck in degradation efficiency. To overcome this limitation, the recombinant enzymes rEG1 and rβG1 were expressed in X-33. A functionally enhanced enzyme cocktail (rEG1-rβG1-Mafic-2001 = 0.05:0.09:0.86) was developed via a mixture design to achieve a reducing sugar yield of 2.77 mg/mL from Chinese distillers' grains (CDGs). Structural analyses revealed that the optimized enzyme cocktail disrupted the reticulated fiber architecture of CDGs and attenuated the characteristic Fourier-transform infrared spectroscopy peaks of lignin, cellulose, and hemicellulose. This study elucidates the synergistic lignocellulose deconstruction mechanism of Mafic-2001 and establishes a precision enzyme-supplementation strategy for efficient CDG bioconversion, providing a scalable platform for the valorization of lignocellulosic biomass.
木质纤维素的高效降解对于农业废弃物的资源化利用和减少环境污染至关重要。高效的降解过程需要一种能够全面解构木质纤维素成分的酶混合物。在本研究中，对稻草诱导的Mafic - 2001的分泌蛋白组进行了检测，并对其酶组成和反应条件进行了优化。Mafic - 2001分泌的酶混合物包括木质素分解酶、纤维素酶和半纤维素酶。然而，与纤维二糖水解酶的相对丰度相比，内切葡聚糖酶（EG）和β - 葡萄糖苷酶（βG）的相对丰度分别仅为64.37%和10.69%，这表明在降解效率方面存在关键瓶颈。为克服这一限制，重组酶rEG1和rβG1在X - 33中表达。通过混合设计开发了一种功能增强的酶混合物（rEG1 - rβG1 - Mafic - 2001 = 0.05:0.09:0.86），以从中国酒糟（CDG）中获得2.77 mg/mL的还原糖产量。结构分析表明，优化后的酶混合物破坏了CDG的网状纤维结构，并减弱了木质素、纤维素和半纤维素的特征傅里叶变换红外光谱峰。本研究阐明了Mafic - 2001协同解构木质纤维素的机制，并建立了用于高效CDG生物转化的精确酶补充策略，为木质纤维素生物质的资源化提供了一个可扩展的平台。
