厌氧真菌纤维降解酶及其应用潜力的研究进展

Fiber-degrading enzymes of anaerobic fungi and their potential for applications: a review

摘要:

反刍动物的瘤胃是已知的纤维降解能力最强的天然发酵罐，其发酵粗纤维的能力很大程度上依赖于其中栖息的各类微生物的功能。厌氧真菌作为瘤胃内的一类低丰度菌群，最先定殖到宿主动物摄入的纤维质饲料上，并通过分泌大量高效的碳水化合物活性酶降解粗纤维。然而，由于缺乏足够的基因组信息和有效的厌氧真菌遗传操作系统，目前国内外对厌氧真菌分泌的纤维降解酶及其降解机制的研究进展有限。本文对厌氧真菌的分类及已发表的基因组信息进行概述，介绍了各类纤维降解酶及纤维小体的组成结构和催化机制特点，并对纤维降解酶在生物质能、饲料处理、纺织造纸及食品加工等方面的应用进行总结。研究厌氧真菌纤维降解酶的作用特性，将有助于完善其在瘤胃环境中有效竞争资源并降解粗纤维的知识体系，也将进一步了解其生物技术应用潜力，为工业生产中应用酶制剂提供新思路。

Abstract:

The rumen of ruminants is known as a natural fermenter with the strongest fiber-degrading ability. The various microorganisms inhabiting the rumen confer it the ability to digest plant feed. As a group of microorganisms with low abundance in the rumen, anaerobic fungi are the first to colonize the cellulosic feed ingested by host animals and degrade lignocellulose by secreting massive efficient carbohydrate-active enzymes. However, due to the lack of sufficient genomic information and an effective genetic operating system for anaerobic fungi, the research on fiber-degrading enzymes secreted by anaerobic fungi and their degradation mechanisms is limited. This paper summarized the taxonomy and published genome information of the anaerobic fungi in the rumen, introduced the fiber-degrading enzymes and the structure and catalytic mechanism of cellulosomes, and recapitulated the applications of such enzymes in biomass energy, feed processing, textile, papermaking, and food processing. Studying the properties of fiber-degrading enzymes in anaerobic fungi will improve our understanding of their ability to degrade lignocellulose and their competition for resources in a highly complex rumen environment. Further, it will help us to learn the application potential of the enzymes in biotechnology and provide new strategies for the application of the enzymes in industries.