The Preparation Of Chitosan By Fermenting Monascus Spp.

The culture medium for producing chitosan by fermenting monascus spp. were optimized. The effects of carbon source,nitrogen source,the their ratio on biomass and mycelia cell wall quantity were studied, so that gained the optimal carbon source,nitrogen source,the their ratio. From the experiments, adding to appropriate Mg2+ and biotin can increase biomass in evidence. The components of fermenting culture for monascus spp. were determined as follows: 4 % glucose, 2%peptone, 0.3% MgSO4 ?7H2O, 0.2%NaNO3,0.1 %KH2PO4, 1 % biotin. The fermentation conditions for producing chitosan was optimized, the optimal condition of fermentation was as follows: temperature 34℃, pH 6.0, amount of medium per flask 100ml/500ml, rotation speed of shaking bed 200rpm.The processing conditions of crashing cell and wiping protein , decolor , taking off acetyl in mycelia cell wall were studied, the optimal extracting processing routine was as follow: thallus→crush up→crashing cell and wiping protein(firstly 2% HC1, temperature 100℃, ratio of solid and liquid 1 : 6, disposing time 1h, centrifugal filtration, secondly 15%NaOH, temperature 100℃, ratio of solid and liquid 1 : 6, disposing time 1h) →centrifugal→filtration and washing to pH 7.0→decolor(10% H2O2 liquor(ratio of solid and liquid 1 : 20), 80℃, 1h)→not dissolve substance→drying→taking off acetyl(alkali concentration C_NaoH50%, temperature 130℃, ratio of solid and liquid 1 : 4, disposing time 3h) → centrifugal→filtration and washing to pH 7.0→taking up (2%acetic acid) →deposition(20%NaOH adjust to liquor's pH 9.0)→not dissolve substance→dryness→chitosan.The culture medium for producing chitosan by fermenting Aspergillus niger were optimized. The components of fermenting culture for Aspergillus niger were determined as follows: 4% glucose, 4%corn steep liquor , 0.3% MgSO4 ?7H2O, 0.2%NaNO3 ,0.1%KH2PO4. The optimal condition of fermentation was as follows: temperature 30℃, pH 6.0, rotation speed of shaking bed 200rpm.The experiments on abstracting chitosan from the waste monascus spp., Aspergillus niger and yellow wine mycilium were studied. The yield ratio for abstracting chitosan from hongqu rice that had abstracted hongqu pigments was 2.32%, the yield ratio for abstracting chitosan from monascus spp mycilium that had abstracted hongqu pigments was 5.37%, the yield ratio for abstracting chitosan from waste residue in citric acid fermentation was 6.65 % , and waste residue in yellow wine fermentation was 0.75 %.