Insight into the Functionality of Microbial Exopolysaccharides by NMR Spectroscopy and Molecular Modeling

Abstract

Microbial polysaccharides represent an important class of microbial polymers with diverse functions such as biofilm formation, thickening, and gelling properties as well as health-promoting properties. The broad range of exopolysaccharide (EPS) functionalities has sparked a renewed interest in this class of molecules. Chemical, enzymatic as well as genetic modifications by metabolic engineering can be used to create large numbers of analogous EPS variants with respect to EPS functionality. While this top–down approach is effective in finding new candidates for desired functionality, there seems to be a lack of the corresponding bottom–up approach. The molecular mechanisms of the desired functionalities can be established from Nuclear Magnetic Resonance (NMR) and molecular models and it is proposed that these models can be fed back into the biotechnology by using a quantitative structure–property approach. In this way it will be possible to tailor specific functionality within a given design space. This perspective will include two well-known commercial microbial EPS examples namely gellan and diutan and show how even a limited use of multiphase NMR and molecular modeling can increase the insight into their different properties, which are based on only minor structural differences.

Metabolomics Deciphered Metabolic Reprogramming Required for Biofilm Formation

“…Bacterial cells in biofilm mode have extraordinary survival ability 21 to resist the environmental stress largely via the protective EPS. Amino acid metabolism, carbohydras metabolism and glycolipid metabolism in bacteria were not only responsible for the biosynthesis and storage of accessible energy but also were utilized for synthesizing the secreted components such as amino acids, sugars, lipids, uridines and organic acids, which are essential for EPS production during biofilm formation 22 . Those metabolic pathways were highlighted in this study to have significantly metabolic reprogramming that triggered the biofilm formation from metabolic perspective (Fig.…”

Exopolysaccharides from Marine and Marine Extremophilic Bacteria: Structures, Properties, Ecological Roles and Applications

“…Mono- and two-dimensional spectra of both 1 H and 13 C nuclei provide essential and definitive information on the primary structure of a carbohydrate chain. The detailed use of NMR in carbohydrates structural elucidation have been extensively reviewed in dedicated papers [ 53 , 54 , 55 , 56 ].…”

Mass Spectrometry based Metabolomics Deciphered Metabolic Reprogramming That Was Required for Biofilm formation in UropathogenicEscherichia coli

“…Bacterial cells in biofilm mode have extraordinary survival ability (Chauret, 2011) to resist the environmental stress largely via the protective EPS. Amino acid metabolism, carbohydras metabolism and glycolipid metabolism in bacteria were not only responsible for the biosynthesis and storage of accessible energy but also were utilized for synthesizing the secreted components such as amino acids, sugars, lipids, uridines and organic acids, which are essential for EPS production during biofilm formation (Larsen and Engelsen, 2015). Those metabolic pathways were highlighted in this study to have significantly metabolic reprogramming that triggered the biofilm formation from metabolic perspective (Figure 4).…”