Microbial enzyme systems for lignin degradation and their transcriptional regulation  

作　　者：Takanori FURUKAWA Fatai Olumide BELLO Louise HORSFALL 

机构地区：[1]School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, UK

出　　处：《Frontiers in Biology》2014年第6期448-471,共24页生物学前沿（英文版）

摘　　要：Lignocellulosic biomass is the most abundant renewable resource in nature and has received considerable attention as one of the most promising alternatives to oil resources for the provision of energy and certain raw materials. The phenolic polymer lignin is the second most abundant constituent of this biomass resource and has been shown to have the potential to be converted into industrially important aromatic chemicals after degradation. However, due to its chemical and structural nature, it exhibits high resistance toward mechanical, chemical, and biological degradation, and this causes a major obstacle for achieving efficient conversion of lignocellulosic biomass. In nature, lignin-degrading microorganisms have evolved unique extracellular enzyme systems to decompose lignin using radical mediated oxidative reactions. These microorganisms produce a set of different combinations of enzymes with multiple isozymes and isoforms by responding to various environmental stimuli such as nutrient availability, oxygen concentration and temperature, which are thought to enable effective decomposition of the lignin in iignocellulosic biomass. In this review, we present an overview of the microbial ligninolytic enzyme systems including general molecular aspects, structural features, and systematic differences in each microorganism. We also describe the gene expression pattern and the transcriptional regulation mechanisms of each ligninolytic enzyme with current data.Lignocellulosic biomass is the most abundant renewable resource in nature and has received considerable attention as one of the most promising alternatives to oil resources for the provision of energy and certain raw materials. The phenolic polymer lignin is the second most abundant constituent of this biomass resource and has been shown to have the potential to be converted into industrially important aromatic chemicals after degradation. However, due to its chemical and structural nature, it exhibits high resistance toward mechanical, chemical, and biological degradation, and this causes a major obstacle for achieving efficient conversion of lignocellulosic biomass. In nature, lignin-degrading microorganisms have evolved unique extracellular enzyme systems to decompose lignin using radical mediated oxidative reactions. These microorganisms produce a set of different combinations of enzymes with multiple isozymes and isoforms by responding to various environmental stimuli such as nutrient availability, oxygen concentration and temperature, which are thought to enable effective decomposition of the lignin in iignocellulosic biomass. In this review, we present an overview of the microbial ligninolytic enzyme systems including general molecular aspects, structural features, and systematic differences in each microorganism. We also describe the gene expression pattern and the transcriptional regulation mechanisms of each ligninolytic enzyme with current data.

关 键 词：lignocellulose biorefinery lignin degradation lignin peroxidases manganese peroxidases versatile peroxidases LACCASES 

分 类 号：X520.2[环境科学与工程—环境工程] TQ351.013[化学工程]