Extraction Of Waste Mycelium Of Aspergillus Niger And Partial Properties Of Chitosan

This paper aims to explore the feasibility of enzymatic extraction of chitosanfrom the waste Aspergillus niger mycelium; to optimize the technology which to getrid of Aspergillus niger mycelium cell wall by using Acid-heating extraction and toextract chitosan by using organic acids; to analyze the quality of chitosan which isobtained from comprehensive extraction process; to research the antibacterial activity,clarified and flocculation characteristics of the chitosan which had been changedifferent molecular weight through the electron beam irradiation. The results ofresearch were as follows:1. Based on single factor experiment Box-Behnken experimental design, theAcid-heating extraction of chitosan has been optimized. The results indicated that cellwall breaking temperature of100℃, cell wall breaking time of1.6h, andconcentration of hydrochloric acid of2.1%were the optimum condition. Theexperimental values of chitosan yield were10.87%, and the relative error with thetheoretical value11.06%was1.72%.2. Based on single factor experiment Box-Behnken experimental design, theOrganic acid process of chitosan has been optimized. The results indicated thatextraction temperature of100℃, extraction time of1.6h, and concentration of aceticacid of2.00%were the optimum condition. The experimental values of chitosan yieldwere10.91%, and the relative error with the theoretical value11.08%was1.53%.3. The chitosan’s extraction ratio was13.2%by using integrated process. Afterqualitative and quantitative analysis and quality analysis, as a result, extracts areβ-type chitosan, which content of87.1%. Its quality indicators meet the relevantstandards.4. After the electron beam degradation, this experiment has6groups of different molecular weights Chitosan. These Chitosan have been applied to Staphylococcusaureus antibacterial experiments. The result indicates that changes in molecularweight have important influence on its bacteriostatic ability. The content of chitosanantibacterial liquid and pH value and the type and concentration of antibacterial liquidsolvent have different effects on the bacteriostatic effect of chitosan.5. The dosage of chitosan, clarified temperature, clarified time, speed of agitatorand pH value of chitosan have varying degrees effects of clarification of sweetsorghum juice.