Use of bacterial cellulose (BC) from a mutated strain for BC-starch composite film preparation

Abstract

Bacterial cellulose (BC), as a promising biodegradable natural material, possesses great application potential in biodegradable composites as a substrate or filler. But, it is yet unclear whether BCs from different sources would affect the BC composite properties. Here, Komagataeibacter xylinus ATCC 53524 and its mutated strain CGMCC 21569 were used as BC-producing strains, and their BCs were applied to prepare BC-starch composite films. As a result, the BC from the mutated strain CGMCC 21569 had a higher molecular weight, crystallinity, fiber diameter, and thermal stability than that from its original strain ATCC 53524. The composite film prepared from the former showed a higher Young's modulus without the reduction of tensile strength and elongation at break. Comparative genome analysis between the two strains indicated that the genes bcsA_1, acsAB_1, epsJ_1 and bglB_1 might affect the biosynthesis of BC, specifically its chain length (molecular weight). The study provided interesting information for further genetically modifying the strain to produce customized BC for manufacturing excellent BC composite films.