Of Acetobacter Xylinumnust4.2 Production Of Bacterial Cellulose Fermentation Kinetics Preliminary Study

Bacterial cellulose has wide applications in paper industry, medicine industry, biomedical engineering and food industry, because of its high purity, high water retention capability, favorable biocompatibility and biodegradable property. In this thesis, measurement method of cells concentration, optimization of fermentation conditions in shake flask, fermentation kinetic model, ventilation volume influence in the preliminary scaling up test in air-stirred fermentation tank during production of bacterial cellulose by Acetobacter xylinumNUST4.2, which is screened by ourselves was studied..In the measurement of cells concentration, it is better to degrade bacterial cellulose using cellulase fisrt, then the total cells could be measured by turbidimetric determination.The result of Plackett-Burman design showed signification factors were temperature, initial pH, liquid volume in turn. In the optimization of fermentation conditions in shake flask applied Response Surface Methodology, Box-Behnken design gave the best combination of temperature, initial pH and liquid volume, which were 28.50℃,5.86,49.06ml in turn, and the best theoretical production of 5.9994g/L, while average measured value was 6.1932g/L. Then a non-structure model of microorganism growth, a production formation model and a limited substrate of glucose consumption model were established.In the preliminary scaling up test in air-stirred fermentation tank, ventilation volume had great influence on growth of Acetobacter xylinumNUST4.2 and synthesization of bacterial cellulose. A suitable ventilation volume should meet the needs of cells growth and ensure energy towards bacterial cellulose synthesis.