微生物降解利用木质纤维素的协同作用

Synergistic systems for biodegradations of lignocellulose in microorganisms: a review

摘要:

木质纤维素复杂的结构组成，是制约高效降解利用这一资源、发展生物炼制的瓶颈。微生物的多酶 (菌) 体系可有效降解木质纤维素。除好氧微生物的游离酶协同系统之外，主要存在于厌氧细菌中的纤维小体也是有序、高效的协同降解纤维素的复合体系。近年来，在天然纤维小体研究的基础上，研究者们成功设计、构建了人工纤维小体，加深了对这一复合体系的组成单元的理性认识。另外，菌群共培养技术利用各组成菌株代谢途径的协同作用实现了木质纤维素的高效降解。最后，引入异源纤维素酶，可改造现有工程菌株的代谢网络，提高工程菌发酵生产终产物的能力。这些技术有利于实现一步转化生产乙醇的联合生物工艺，有助于提高生物炼制的产率、降低生产成本。

Abstract:

Lignocellulose is the most abundant natural biomass. Bioconversion of lignocelluloses becomes a bottleneck for biorefinery, because of its complex structures and heterogeneous composition. Besides screening or engineering approach for single free enzymes with improved properties, an alternative approach is to study synergistic pattern with hydrolysis systems or mimic natural cellulosome for better performance in cellulolytic substrate degradation. Besides, bacterial co-cultures provide another synergistic cellulolytic system. Engineered strains with modified metabolic network could facilitate consolidated bioprocess by increasing yields as well as reducing costs.