Production Of Chitosan By Fermentation And It's Application

The fermentation conditions for producing chitosan were optimized. The components of slant culture for preserving Aspergillus niger were determined as follows: corn steep liquor 4.0%, glucose 2.0%, MgSO4 2.0%, agar 2.0%, tap water, nature pH(4.3). The components of fermentation culture medium were determined by the orthogonal design experiment as follows: corn steep liquor 4.0%, glucose 2.0%, MgSO4 2.0%, tap water, nature pH. We also made primary study on the characteristics of fermentation process in the fermentation tank(5L). The DCW, Dissolved Oxygen, pH, concentration of glucose, Mg2+ were measured and the varied curves were also described.The effects on KLa of single type and mixted type stirrer's were studied. Curved vane stirrer was selected. At the mean time, the effects on shear force to Aspergillus niger of every type stirrer were compared and the shear force of curved vane stirrer was the lest.The fed-batch was studied,however it couldn't markedly increase the DCW. The probable reasons were also analyzed.Microwave technique was used here to optimize the deacetylation in the process of extracting chitosan. This technique has the advantages of less alkali demanded , shortening of extracting time, and high molecular weight of chitosan. The chitosan separated was identified which has the same IR structure with that from shrimp and crab, but the purity is lower.Application of chitosan in flocculent of active sludge was studied. The result showed that the flocculent effect could be comparable of polyacrylamide , and better than poly-aluminium. Adsorption of Cr3+ using non-viable Aspergillus niger was conducted, the adsorption content was 236mgCr3+/g dry mycelium.