Deuteration selectivity of bacterial cellulose in D₂O-based culture media and isotope effects

Deuteration of cellulose is one of the most attractive approaches for clarifying its crystal structure, dissolving behavior in ionic liquids, and hydrogen bonding systems. However, current deuteration methods for cellulose have critical disadvantages in terms of the cost and efficiency of deuteration, large-scale production, and selectivity of the deuteration positions. Therefore, in this study, we aimed to produce deuterated bacterial cellulose (D-BC) using Komagaeibacter xylinum in culture media containing D₂O as the only source of deuterium. In addition, the physical properties of the D-BC samples obtained with different degrees of deuteration were investigated. Notably, this deuteration method successfully achieved hydrogen/deuterium exchanges (H/D exchange) at the hydroxyl groups and CH bonding on the glucopyranose ring. Moreover, owing to the isotope effect the thermal stability and ultraviolet resistance of D-BC samples increased. This is the first time to demonstrate that the H/D exchange position dependent on the D₂O concentration in the cultivation media. Overall, these findings provide comprehensive insights into the physiochemical properties of cellulose and the development of deuterated polymer materials.