Mathematical Modeling 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 increasing 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.

Linking Engineered Gene Circuit Kinetic Modeling to Cellulose Biosynthesis Prediction in Escherichia coli: Toward Bioprocessing of Microbial Cell Factories

“…coli, as a well-characterized cell factory, represents the workhorse of choice for accomplishing controlled production of a variety of products due to its ease of reprogramming using synthetic biology tools and its robust bioprocessing capabilities. , Major concerns regarding the use of engineered gene circuits are related to the metabolic responses associated with recombinant expression, such as growth inhibition and protein synthesis leading to plasmid instability. , These responses result in heterogeneous cell populations in which differential growth of plasmid-bearing and plasmid-free cells occurs . Regarding BC biosynthesis, only a few studies have been published on mathematical modeling of naturally synthesized BC, which mainly concentrated on empirical microbial growth, glucose consumption, and substrate mass transfer prediction ignoring the regulatory mechanisms involved. , …”

“…30 Regarding BC biosynthesis, only a few studies have been published on mathematical modeling of naturally synthesized BC, which mainly concentrated on empirical microbial growth, glucose consumption, and substrate mass transfer prediction ignoring the regulatory mechanisms involved. 31,32 Herein, the rational modeling approach developed by Tsipa et al (2018) 18 was applied to the gene circuit of cellulose biosynthesis in the E. coli biosystem. Correlation between the levels of mRNAs transcribed and proteins translated is variable dependent on the specific gene and the transcription factors controlling gene expression.…”