بهينه سازي فرمولاسيون محيط كشت قارچ موكوراينديكوس به منظور حداكثر كردن توليد كيتوزان

چكيده انگليسي :

Optimization of Culture Media Formulation of Mucor indicus for Maximization of Chitosan Production Marzieh Mohammadi mrz moh@yahoo com 21 January 2013 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Akram Zamani zamani akram@cc iut ac ir Keikhosro Karimi Karimi@cc iut ac ir Abstract Chitosan is a copolymer containing randomly distributed glucosamine GlcN and N acetyl glucosamine GlcNAc monomers GlcN is the dominant monomer in chitosan more than 60 Chitosan is a valuable biopolymer which is found in the cell wall of zygomycetes fungi such as Mucor indicus The chitosan content in the cell wall of these fungi strongly depends on the cultivation conditions To compare the chitosan production under various conditions it is necessary to use of an accurate easy and reproducible technique Nowadays different methods have been used for determination of chitosan in fungal cell wall In this study firstly performance of the best available method was investigated In this method chitin and chitosan were converted to anhydromannose through subsequent reactions with sulfuric and nitrous acids Then anhydromannose was converted to its blue colored complex by reaction with 3 methyl 2 benzothiozolone hydrazone hydrochloride MBTH and Iron III chloride FeCl3 The amount of this complex was measured according to colorimetric method However the colored complex was not stable and its absorbance was reduced significantly over time In contrast anhydromannose before conversion to colored complex was stable and concentration of this material was accurately measured employing high performance liquid chromatography HPLC Therefore a new method was presented in this work for accurate and time independent analysis of cell wall The next step of this thesis was changing the fungal cultivation conditions towards improvement of chitosan production in the cell wall of M inidus The new measuring method was used to investigate the effect of different morphologies of Mucor indicus on chitosan concentration in the cell wall Results showed that cells with filamentous morphology had the highest amount of GlcN 0 46 g g cell wall In contrast only half of this value was available in the cell wall of yeast like cells Additionally results showed that similarly the filamentous morphology had the highest amount of GlcNAc 0 18 g g cell wall In contrast it was reduced by changing the morphology into mostly yeast like and purely yeast like forms Moreover filamentous morphology had the lowest amount of phosphate 0 06 g g cell wall while this was increased by changing the morphology into mostly yeast like and purely yeast like forms Interestingly total phosphate and N acetyl glucosamine in three morphology was nearly constant and equal to 24 Therefore the rest of experiments was done using filamentous form of cells In the next step effect of phosphate content on chitosan production by this morphology was investigated Results showed that with increasing concentrations up to 0 5 g l of potassium dihydrogen phosphate in the culture media phosphate was entirely consumed by the fungus while at higher concentrations a significant fraction of phosphate remained intact In other words despite significant increase in the amount of phosphate in the culture media small changes were observed in the phosphate uptake by the fungus Additionally the major fraction of consumed phosphate was placed in the body of fungi while only trace amounts was stored in the cell wall about 0 01 g l Results showed that in culture containing no potassium dihydrogen phosphate the highest chitosan production was achieved key words Mucor indicus morphology chitosan HPLC phosphate PDF created with pdfFactory trial version www pdffactory com

محمدي، مرضيه

بهينه سازي فرمولاسيون محيط كشت قارچ موكوراينديكوس به منظور حداكثر كردن توليد كيتوزان

HPLC و فسفات