Mathematical modelling of bacterial cellulose production by acetobacter xylinum using rotating biological fermentor

Abstract

Bacterial cellulose (BC) has a basic cellulose structure that gives high purity, high crystalline ability, high mechanical strength, and high water holding capacity. During the last few decades, BC has gained as an important biomaterial because of these unique physical and chemical characteristics. BC is synthesized by Acetobacter xylinum extracellularly in a suitable substrate media. Researchers have produced BC using a synthetic media or using coconut water and inoculating with Acetobacter xylinum in a static fermentation system. In order to eliminate shortcomings in static fermentation and to achieve increased cellulose production, agitated and aerated fermentation systems were experimented. Rotating Biological Fermentor (RBF) is an is aerated and agitated system, which gives continuous oxygen flux to the fermentation medium thereby ncreasing the yield of biomass and cellulose synthesized. In this study, a mathematical model for the synthesis of BC in a RBF system was developed. The growth of cellulose is considered as a biofilm from a mono culture. Glucose depletion, cellulose production and microbial growth in the fermentation medium were explained using the developed models. It was shown that the simulated and experimental results were in close agreement. In addition, the model was successful in predicting yield of cellulose at different rotational speeds of the RBF unit.