| Chitosan is called as polyamino-D-glucose,and is the shucking acetyl off production from chitin, which is the exclusive alkaline amylase in the nature. Because of chitosan's special character, it is used wildly in medication, printing dye, chemical, food, agriculture, and so on. At present, the shell of shrimp and crab are used as the source of industrialized production chitosan. But this extraction way of production chitosan uses up substantive energy, pollutes environment,and the sources is restricted by season and location.Since the next century it was approved that the chitin exit in the wall of fungicidal cell, the reports of extracting chitosan from mycelium of fungal appeared more and more.. But the most part of research focused on the way of extraction, but is not much for research about filtrating high yield fungus and optimizing cultivate conditions. This experiment mainly used Boletus edulis to ferment liquor for getting effective composition and best cultivate conditions, and determining the extraction from ferment liquor. The mainly research content and results is :The experimental firstly optimized single factors, including: carbon source, nitrogen source and cultivate conditions. Confirmed the best basic culture medium to ferment Boletus edulis, glucose as the best carbon source, yeast extract as the best nitrogen source. The results of optimized cultivate conditions: initial pH was pH5.5, temperature was 28℃, broth content was 80mL, in 250mL flask for 6 days.Chosed glucose, nitrogen, initial pH, and broth content as four key factors based on single factor research. Research used DPS data manage software to design RSM method for optimizing cultivate best conditions of Boletus edulis ferment to produce chitosan. The results showed: glucose of 30.53g/l,yeast extract of 7.02g/l, optimal temperature was 28℃, initial pH at 5.64, the broth content of 77.42ml in 250ml flask for 6 days. The max quality of Chitosan is 3.81g/l, taking 15.43% the dry weight of mycelium.The experiment determined the production from Boletus edulis by IR and UV. Confirmed that the production from Boletus edulis was chitosan. And the chitosan was high DD and purity, reached good quality.Then used the chitosan of Boletus edulis to restrain bacteria develop. The results showed: the 2% concentration of chitosan acetic acid liquor have antibacterial ability for both bacteria. And the antibacterial ability to E.coli was better than B.subtilis. So established base for chitosan from Boletus edulis application in practice. |
