Bacteria make modified cellulose

Abstract

Cellulose is an abundant biopolymer made of strands of β-1,4-linked glucose units. It provides mechanical strength to plants and biofilms made by bacteria. A team led by Lynette Cegelski of Stanford University and Regine Hengge of Humboldt University of Berlin now reports that the cellulose made by bacteria is a chemically modified version (Science 2018, DOI: 10.1126/science.aao4096). Using solid-state nuclear magnetic resonance spectroscopy to analyze the structure of the cellulosic material, the researchers determined that it contains a phosphoethanolamine group (shown in blue) attached to the C6 position of a glucose ring in the repeating unit. The modification had not been observed before because standard HCl hydrolysis degrades the modification, leaving only glucose, glucose-6-phosphate, and ethanolamine. The researchers also identified the genes behind the modification. They propose that a protein known as BcsG acts as an enzyme that installs phosphoethanolamine and that two other proteins in the sa...