توصيفگر ها :
گلوكز آمين , موكور اينديكوس , هورمون ايندول , استيك اسيد , هورمون كينتين , فسفات , پتاسيم , فلزات كم مقدار , عصاره مخمر
چكيده انگليسي :
71 Optimization of Biological Production of Chitosan Zahra Safaei zs safaie@ce iut ac ir 15 January 2014 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Akram Zamani zamani akram@cc iut ac ir Keikhosro Karimi karimi@cc iut ac irAbstractChitosan is a copolymer of glucosamine GlcN and N acetyl glucosamine GlcNAc units that glucosamine unitsare predominant in that structure Chitosan has numerous applications in biotechnology food agriculture pharmacy and medical and commercially produce by deacetylation of chitin in shells of crustaceans Nowadaysthe alternative source of chitosan is cell wall of zygomycetes fungi in which chitosan appears naturally Laststudies show fungal cultivation conditions including formulation of culture media strongly influence the growthof zygomycetes and amount of chitosan in their cell wall In this study effects of phosphors potassium yeastextract trace metals and two plant growth hormones i e indole 3 acetic acid IAA and kinetin KIN wasstudied on chitosan production by M indicus At first a semi synthetic culture media was used and GlcN content was 14 At first step the effects of plantgrowth hormones were investigated Maximum content of GlcN was observed at 1 mg l of both hormones Increasing from 14 to 45 and 34 was obtained by using 1mg l of IAA and KIN respectively In the nextstep effects of phosphate on chitosan production was studied KH2PO4 was removed from culture media anddifferent concentration of phosphoric acid was added In this step potassium concentration was kept constant byadding 1 44 g l KOH to all of the samples The highest GlcN yield 32 was achieved at culture media withoutphosphate In the next step the effects of potassium concentration was acquired By using 2 5 g l KOH maximumGlcN content 0 42 was obtained Also the effect of using trace metals solution was determined in this step Theresults showed significant improvement in chitosan production Final step of this study was assigned to effects ofyeast extract in optimum amounts of phosphate potassium hormones and in presence of trace metals solution Remarkable increasing in chitin production and reduction in chitosan yield was resulted in absence of yeastextract or concentration of less than 2 g l while noteworthy intensifying in chitosan production was observed athigher concentration of yeast extract and maximum of GlcN yield 51 was obtained at 5 g l of it Higherconcentrations of yeast extract had negative effect on chitosan content and GlcN yield return to 17 20 again Key words chitosan glucosamine indole 3 acetic acid kinetin phosphate potassium tracemetals yeast extract
