Orientated Bacterial Cellulose Culture Controlled by Liquid Substrate of Silicone Oil with Different Viscosity and Thickness

We report the effect of oxygen and viscoelasticity of culture interface on the orientation of bacterial cellulose (BC) fibril synthesized by Acetobacter xylimum (ATCC 53582) at a silicone oil/culture medium (liquid/liquid system) interface. In this work, we used the silicone oil with various kinematic viscosities, v ranging from 10 to 3000 centistokes (CS). We found that the birefringence, Delta n as a measure of degree of orientation, fibril width, w, swelling degree, q, and tensile modulus, E, increased as increase the thickness and viscosity of silicone oil. However, fracture stress, sigma(F) and fracture strain, lambda(F) decreased with increase the silicone oil thickness and viscosity. Further, we also found that viscoelasticity of culture interface plays an important role to determine the orientation alignment of BC fibrils. Meanwhile, oxygen did not show significant influence on orientation of BC fibrils.