Understanding 3D Networks Structure during Biosynthesis of Cellulose from Bacteria

Materials sourced from renewable sources and synthesized under mild conditions offer coupled benefits in terms of sustainability, in contrast to petroleum-derived polymers, which are known contributors to pollution and adverse health consequences. Bacterial cellulose (BC) consists of high aspect ratio fibrils that bundle into fibers, forming 3D networks which can be influenced by growth conditions. BC pellicles, which are produced in static conditions and are often used in research and applications, exhibit a layered structure at the mesoscale. These layers form as successive entangled fiber networks are deposited extracellularly during BC growth. The layered structure is a distinctive feature of BC pellicles and contributes to their unique mechanical properties. The growth conditions during BC fiber synthesis significantly influence the alignment, crystallinity, and 3D morphology of the formed network. However, there is a lack of understanding of the fundamentals of cellulose fiber aggregation into network assemblies. Understanding how nanoscale fibrils bundle, entangle, and form larger structures at the mesoscale is crucial for tailoring BC's properties for various applications, from biotechnology to materials science. We investigate the intricate structural evolution of BC, spanning from the nanoscale to the mesoscale, with a specific focus on understanding entanglement phenomena. Furthermore, our investigation explores the significance of fibril entanglement in BC networks, providing insights into the intricate process by which individual nanofibrils interweave to construct the broader mesoscale framework. This research aims to provide a comprehensive understanding of BC's structural development.