A chitinolytic organism was cultured from a lotic habitat in central Indiana. It was isolated on the basis of its hydrolytic activity on chitin agar. It was subsequently identified as EF-4a. The chitinases of the EF-4a were isolated, purified and concentrated. A colloidal chitin suspension was then incubated with the enzyme. Samplings were taken at one minute, one hour and 24 hours. The samplings were filtered through a Swinney filtration unit and immediately after applied to a Beckman Ultrasil Amino column. It was eluted with acetonitrile: water (75:25) at a flow rate of 2 ml/min. The absorbance at 214 nm was monitored using the Beckman 160 UV detector. The chromatographs were analyzed for product elaboration. It was observed that EF-4a produced soluble, extracellular enzymes. The enzymes were a chitinase-chitobiase complex. The enzymes' action on chitin was immediate. There were varying reaction products including G1cN, GlcNAc, chitobiose, chitotriose and higher order oligomers. There was also chromatographic evidence suggesting a and B anomers of these saccharides.

No description available.

Chitin is a natural polymer which is extracted from a number of biological sources. This polymer is deacetylated to form the related polymer chitosan. The design and preparation of chitosan derivatives has been investigated to tailor the physical and chemical properties towards specific applications. To this end, this thesis describes the synthesis and characterisation of a number of chitosan derivatives. The prepared polymers contained either naphthalimide groups, thiol groups, poly(methyl methacrylate) side chains or poly(oligoethylene glycol methyl ether methacrylate) side chains. Chitin was successfully extracted and purified from squid pens by literature methods to give polymers with DD values from 12 to 23%. The Kurita method was used to obtain chitosan samples with a range of DD values from 75 to 91%. The prepared polymers were characterised by microanalysis, IR, �H NMR and solid-state ��C NMR spectroscopy. The MW distributions of the chitosan samples were determined by GPC in 0.3 M AcOH/0.2 M AcONa(aq) solution with dextran standards. The N-(naphthalimide)-chitosan derivatives were fluorescent materials and were typically prepared from the reaction of 4-bromonaphthalic anhydride with chitosan. This reaction was thoroughly investigated to find the optimal reaction conditions. The bromo groups were subsequently displaced by one of four nucleophiles: dimethylamine, piperidine, methoxide or vinylferrocene. The polymers were characterised by microanalysis, GPC, IR, �H NMR, UV-vis and fluorescence spectroscopy. The excitation and emission wavelengths and Stokes shifts were dependent on the substituent present in the naphthalimide group. Chitin and chitosan were sequentially reacted with tosyl chloride, potassium thioacetate and sodium methoxide to form the thiolated derivatives. The success of the tosylation reaction was dependent on the synthetic route used and the DD of the polysaccharide. The thiolated chitin polymers were well defined although the samples were completely insoluble. The thiolated chitosan polymers were also characterised and were highly swollen in acetic acid solution. These thiolated polysaccharides were used as macroinitiators for the free-radical polymerisation of MMA. The products obtained from the reaction of 6-mercaptochitin in DMSO with MMA were typically prepared with low yields and low amounts of grafting. The products prepared from 6-mercaptochitosan under the same conditions contained larger amounts of the synthetic polymers although the products were highly variable. MMA was subsequently polymerised with 6-mercaptochitosan in acetic acid buffer to form highly grafted copolymers. Chitosan was reacted with the monomer OEGMA by ATRP to form chitosan-graft-poly(OEGMA) copolymers. Two synthetic routes were investigated. The "grafting-from" route involved. the formation of a chitosan macroinitiator and polymerisation of OEGMA with this polymer. The polymers contained a large amount of grafted side chains as estimated from the �H NMR spectra. However, the purification was not satisfactory as determined by the presence of two peaks in the GPC traces. The "grafting-to", route involved the formation of poly(OEGMA) by ATRP with activated initiators and subsequent attachment to chitosan. The prepared copolymers showed large differences in their appearance with even very low amounts of grafting. The purification of the polymers prepared by this method was successful with no detectable homopolymer as determined by GPC analysis.

Chitin is a natural polymer which is extracted from a number of biological sources. This polymer is deacetylated to form the related polymer chitosan. The design and preparation of chitosan derivatives has been investigated to tailor the physical and chemical properties towards specific applications. To this end, this thesis describes the synthesis and characterisation of a number of chitosan derivatives. The prepared polymers contained either naphthalimide groups, thiol groups, poly(methyl methacrylate) side chains or poly(oligoethylene glycol methyl ether methacrylate) side chains. Chitin was successfully extracted and purified from squid pens by literature methods to give polymers with DD values from 12 to 23%. The Kurita method was used to obtain chitosan samples with a range of DD values from 75 to 91%. The prepared polymers were characterised by microanalysis, IR, �H NMR and solid-state ��C NMR spectroscopy. The MW distributions of the chitosan samples were determined by GPC in 0.3 M AcOH/0.2 M AcONa(aq) solution with dextran standards. The N-(naphthalimide)-chitosan derivatives were fluorescent materials and were typically prepared from the reaction of 4-bromonaphthalic anhydride with chitosan. This reaction was thoroughly investigated to find the optimal reaction conditions. The bromo groups were subsequently displaced by one of four nucleophiles: dimethylamine, piperidine, methoxide or vinylferrocene. The polymers were characterised by microanalysis, GPC, IR, �H NMR, UV-vis and fluorescence spectroscopy. The excitation and emission wavelengths and Stokes shifts were dependent on the substituent present in the naphthalimide group. Chitin and chitosan were sequentially reacted with tosyl chloride, potassium thioacetate and sodium methoxide to form the thiolated derivatives. The success of the tosylation reaction was dependent on the synthetic route used and the DD of the polysaccharide. The thiolated chitin polymers were well defined although the samples were completely insoluble. The thiolated chitosan polymers were also characterised and were highly swollen in acetic acid solution. These thiolated polysaccharides were used as macroinitiators for the free-radical polymerisation of MMA. The products obtained from the reaction of 6-mercaptochitin in DMSO with MMA were typically prepared with low yields and low amounts of grafting. The products prepared from 6-mercaptochitosan under the same conditions contained larger amounts of the synthetic polymers although the products were highly variable. MMA was subsequently polymerised with 6-mercaptochitosan in acetic acid buffer to form highly grafted copolymers. Chitosan was reacted with the monomer OEGMA by ATRP to form chitosan-graft-poly(OEGMA) copolymers. Two synthetic routes were investigated. The "grafting-from" route involved. the formation of a chitosan macroinitiator and polymerisation of OEGMA with this polymer. The polymers contained a large amount of grafted side chains as estimated from the �H NMR spectra. However, the purification was not satisfactory as determined by the presence of two peaks in the GPC traces. The "grafting-to", route involved the formation of poly(OEGMA) by ATRP with activated initiators and subsequent attachment to chitosan. The prepared copolymers showed large differences in their appearance with even very low amounts of grafting. The purification of the polymers prepared by this method was successful with no detectable homopolymer as determined by GPC analysis.

Thesis (M.S.) in Food Science and Human Nutrition--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 120-129 ).

Thesis (Ph.D.)--Washington State University, December 2005. / Includes bibliographical references.

Thesis (Ph.D.)--Washington State University, December 2005. / Includes bibliographical references (p. 115-117).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1980. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 215-221).

No description available.

No description available.