Omics analysis and industrial application prospects of lignocellulose-degrading actinomycetes

Actinomycetes , a group of Gram-positive bacteria with high GC contents, play important roles in hyperthermal lignocellulose degradation in terrestrial habitats. A functional genomics analysis revealed that lignocellulose-degrading actinomycetes have more cellulases than hemicellulases and pectinases. Additionally, the enzymes capable of degrading cellulose were mainly cellobiohydrolases belonging to glycoside hydrolase family 6, with a small number of cellulases belonging to glycoside hydrolase families 9 and 48. In addition to glycoside hydrolases, large numbers of polysaccharide monooxygenases from auxiliary activity family 10 were also identified. Therefore, actinomycetes can efficiently degrade crystalline cellulose by continuous hydrolysis and oxidation mechanisms. Furthermore, some of these enzymes with multiple structural domains can be secreted quickly into the extracellular environment through the twin-arginine translocation system. These lignocellulolytic enzymes have excellent properties, such as high enzyme activity and high temperature and alkali resistance. Therefore, the characteristics and advantages of these actinomycetes in lignocellulose degradation and secondary metabolite production make them well suited for industrial applications.