Research progress of carbohydrate-active enzymes on marine bacteria

Abstract:

Polysaccharides are the main components of macroalgae,phytoplankton,and microorganisms.Polysaccharide degradation products are the main source of marine organic matter.Carbohydrate-active enzymes (CAZymes),the typical functional enzymes for the degradation,modification,and generation of glycosidic bonds of carbohydrate compounds,are the basic functional units in carbohydrate metabolic pathways.Most heterotrophic bacteria are endowed with a complete CAZymes-encoding system,which is the main driving force for carbohydrate metabolism.However,owing to the diversity,complex structures,and functional specificity of CAZymes,there is a lack of a systematic understanding of the members in this family and the molecular mechanisms of action.The development of carbonhydrate chemistry,molecular ecology,microbiology,and bioinformatics allowed an in-depth understanding of the structures of polysaccharides,the degradation pathways,and the action mechanisms of the CAZymes.In this paper,the research advances of CAZymes were summarized.At first,this review introduced the types of polysaccharides in the marine environment and the corresponding methods of qualitative and quantitative analysis.Secondly,we summarized the latest progress of CAZymes and the database status and discussed polysaccharide utilization loci (PULs) and molecular degradation mechanisms of several marine polysaccharides.Finally,we presented a new conceptual model linking polysaccharide structural complexity to bacteria-driven polysaccharide utilization,and introduced the relationship between the polysaccharide degradation by heterotrophic bacteria and the algal bloom dynamics.The purpose of this paper is to enhance the systematic understanding of the molecular functions and ecological significance of CAZymes and deepen the understanding of carbohydrate metabolism in the marine environment.