The Study On The Production Of Fungal Chitosan By Fermentation

Chitosan, the deacetylated form of chitin, has unique properties which make it useful for a variety of industrial applications. In this paper the author improved the technology of chitosan production, high quality chitosan has been prepared with the treatment of low concentration of NaOH and HCl. It is more advanced technology. Because the traditional technology of chitosan production from crab and prawn shells is limited currently with a high producing cost and serious pollution of high concentration of NaOH and HCl.In this paper, production of chitosan was conducted using Aspergillus oryzae 3.951. Chitosan was extracted from mycelia of A. oryaze in shake flask culture. The component of cultivation media in shake flask cultures has been confirmed. In the A. oryaze, chitosan was rapidly produced, while highest yield of extractable chitosan was found in 48 h, 28℃, 160 rpm of cultivation in submerged culture. The yield ratio of chitosan isolated from dry mycelia of A. oryaze was 19.10 %. The degree of deacetylation of chitosan was 87.46 %, and the purity of chitosan was 74.94 %. It is also proved that chitosan could extend vase-life, delay anthesis and climacteric of the cut chrysanthemum.The innovation of the paper is that, firstly, A. oryaze was used as the strain of chitosan production for the first time, which is proved to be becoming to producing chitosan. Secondly, the cultivation media of shake flask culture and a stirred tank fermenter was improved to increase the yield of chitosan. Finally, the technology with low concentration of NaOH and HCl which could reduce the pollution and cost must will be used in the future study and production.