微生物降解木质素的研究进展

Research Progress on Lignin Degradation by Microorganism

木质纤维是地球上最丰富的可再生生物质资源,其三大成分之一的纤维素是生产生物基材料、生物燃料及生物基化学品的重要原料,但是木质素复杂的化学结构阻碍了木质纤维的应用。常规木质素的物理、化学及物理-化学等降解方法常需要高温、高压条件,并且易产生抑制物、造成高能耗和环境污染等问题。微生物介导的生物催化过程通常在温和条件下进行,可以降低能源投入,为木质素的利用提供了更具体、更有效的选择。传统生物降解以白腐菌等真菌为代表,存在预处理周期长、对环境适应性差等问题,而细菌繁殖迅速、环境适应能力强、易于基因操作,成为未来木质素降解菌株的潜在候选者。本文在介绍木质素化学结构的基础上,综述了近年来微生物降解木质素的研究进展,着重分析了降解木质素的微生物(真菌和细菌)、木质素降解酶(过氧化物酶和漆酶)和降解机制,以及微生物降解木质素在脂类、生物塑料、香兰素、废水处理中的应用,并对微生物降解木质素的未来发展进行了展望。

Lignocellulose is the most abundant renewable biomass resource on the earth and cellulose is one of the three components of lignocellulose and is important raw material for the production of bio-based materials,fuels and chemicals.However,the complex chemical structure of lignin limits the application of lignocellulose.Conventional physical,chemical and physical-chemical lignin degradation methods often require high temperature and high pressure conditions,resulting in high energy consumption,inhibitors and environmental pollution.The biocatalysis process mediated by microorganisms is usually carried out under mild conditions,which can reduce energy input and provide a more specific and effective choice for the utilization of lignin.The degradation of lignin by fungi,represented by white-rot fungi,presents the problems of long pretreatment cycle and poor adaptability to the environment.Bacterium becomes the future potential of lignin degradation,owing to its rapid proliferation,profound environmental adaptability and easy genetic manipulation.This review introduced the progress of microbial degradation of lignin on the base of chemical structure,and mainly analyzed the microorganisms(fungi and bacteria),degrading enzymes(peroxidase and laccase)as well as the degradation mechanism.Besides,the applications of microbial degraded lignin in lipids,bioplastics,vanillin and wastewater treatment were summarized and the future development was suggested.