Quitosana é um polímero de baixa toxicidade, biodegradável e biocompatível, obtido pela desacetilação heterogênea de quitina, que é um polissacarídeo encontrado abundantemente na biomassa. Em meios aquosos de acidez moderada, a quitosana também exibe comportamento de polieletrólito catiônico, reunindo, assim, características que favorecem a sua aplicação em diversas áreas, dentre elas, agricultura, medicina, indústrias alimentícia e de cosméticos. As principais limitações ao uso da quitosana em grande escala estão relacionadas à dificuldade em conciliar os custos de produção e a obtenção de quitina/quitosana com características uniformes e presença reduzida de impurezas. De modo geral, os métodos físicos e químicos propostos na literatura favorecem a obtenção de quitosanas mais desacetiladas e com distribuição mais uniforme de unidades, no entanto, são pouco viáveis, principalmente do ponto de vista econômico, para aplicações em escala industrial. Neste trabalho, as alomorfas &alpha;- e &beta;-quitina foram extraídas da biomassa, i. e., cefalotórax de Macrobrachium rosenbergii e gládios de Loligo plei e L. sanpaulensis, respectivamente, e usadas como matérias-primas para obtenção de quitosana empregando diferentes procedimentos. Assim, diferentes metodologias de desacetilação de quitina foram executadas, a saber, a desacetilação heterogênea, a desacetilação precedida pela execução de ciclos térmicos (método FPT) e a desacetilação assistida por ultra-som. Também foi realizado um estudo cinético da reação de desacetilação assistida por ultra-som. Com base nos resultados de %GA das amostras de quitina e de quitosana, os quais foram obtidos por espectroscopia de RMN 1H, análise elementar e titulação condutimétrica, pôde ser observado que o uso de ultra-som favoreceu o processo de desacetilação. Além disso, os resultados do estudo cinético da reação assistida por ultra-som a 100°, 110° e 120°C indicaram que o domínio cinético da reação foi abreviado para tempos inferiores a 30 min e que o patamar de velocidade constante corresponde a uma desacetilação mais completa (GA< 20%) do que aquele atingido com o uso do método de desacetilação heterogênea (20% < %GA < 45%). Estas conclusões estão de acordo com as caracterizações por difração de raios X, as quais revelaram a progressiva destruição dos domínios cristalinos à medida que os produtos foram mais desacetilados. Dessa forma, a desacetilação assistida por irradiação de ultra-som de alta potência possibilitou, de um modo mais simples e rápido, a obtenção de quitosanas com características semelhantes às obtidas após o emprego do método FPT, sendo que este último é relatado na literatura como o método mais eficiente para produção de quitosanas extensivamente desacetiladas. É proposto que a irradiação de ultra-som de alta potência contribuiu para aumentar acentuadamente a área superficial das partículas de quitina, propiciando pleno acesso do hidróxido de sódio aos grupos acetamida do polímero e promovendo a sua desacetilação homogênea. / Chitosan is a low toxicity, biodegradable and biocompatible polymer which is obtained by deacetylating chitin, an abundant polysaccharide. The applications of chitosan in several areas, such as agriculture, food and cosmetic industries, are favored by its cationic polyelectrolyte character, conferred by dissolving chitosan in moderately acid aqueous media. The main limitation to the widespread use of chitosan concerns the compromise between the production costs and the accomplishment of uniform characteristics and reduced amount of impurities. However, the physical and chemical methods currently proposed to deacetylate chitin which allow the production of chitosan with such characteristics are not feasible for large scale production. In this work, the allomorphs &alpha;- and &beta;-chitin were extracted from the biomass, i. e., the cephalothoraxes of Macrobrachium rosenbergii and squid pens from Loligo plei and L. sanpaulensis, respectively, and then they were used as raw materials to produce chitosan. Thus, different methods for deacetylating chitin were used, such as the heterogeneous deacetylation, the freeze - pump out - thaw method (FPT method) and the ultrasound assisted deacetylation. Also, the kinetics of the ultrasound assisted chitin deacetylation was studied. From the values of average degree of acetylation (%DA) of chitin and chitosan samples, which were determined by 1H NMR spectroscopy, elemental analysis and conductimetry, it was observed that the ultrasound treatment favored the deacetylation of chitin. Moreover, the study on the kinetics of the ultrasound assisted chitin deacetylation at 100°, 110° and 120°C showed that the kinetics domain was shortened to times lower than 30 min as compared to the heterogeneous reaction. Additionally, the plateau of constant DA attained at this time corresponds to a more efficient deacetylation (DA< 20%) as compared to the heterogeneous deacetylation (20% < DA < 45%). Accordingly, the X-rays diffraction experiments revealed the progressive destruction of the crystalline domains as the deacetylation reaction progressed. This work showed that the ultrasound assisted chitin deacetylation is a faster and simpler process to produce chitosan as compared to the methods currently used. Moreover, it allows the preparation of chitosans with characteristics similar to those produced by applying the FPT method, a process reported as the most efficient ever developed to promote the deacetylation of chitin, and it allows that in a simpler and faster manner as well. It is proposed that as a consequence of the ultrasound irradiation the superficial area of the chitin particles increased dramatically, increasing the accessibility to the acetamida groups and promoting a nearly homogeneous deacetylation of chitin.

Neste trabalho, amostras de beta-quitina extraída de gládios de lulas foram submetidas ao processo DAIUS, desacetilação assistida por irradiação de ultrassom de alta intensidade, visando à produção de quitosanas extensivamente desacetiladas e de massa molar elevada. Para isso, os parâmetros do processo, a saber, diâmetro do reator, tempo de pulsação da irradiação do ultrassom e tempo de pré-condicionamento visando o intumescimento das partículas de beta-quitina, foram variados utilizando um planejamento fatorial fracionário (23-1). Desse planejamento resultou a execução de quatro experimentos e a triplicata do ponto central. A beta-quitina de partida e as quitosanas obtidas foram caracterizadas por espectroscopia de RMN 1H, espectroscopia da região do infravermelho, difração de raios X, viscosimetria capilar, microscopia eletrônica de varredura e termogravimetria. O parâmetro de acetilação (PA) das quitosanas obtidas foi determinado a partir dos espectros de RMN 1H de modo a permitir a avaliação do tipo de distribuição das unidades GlcNAc e GlcN predominante nas cadeias. As quitosanas apresentaram parâmetro de acetilação variando no intervalo 0,61&lt;PA&lt;0,82, indicando o predomínio da distribuição randômica das unidades GlcNAc e GlcN. A determinação da solubilidade das quitosanas foi baseada na turbidez de suas soluções, sendo todas solúveis em pH &lt; 5, exceto a amostra QT2 que foi insolúvel. A beta-quitina apresentou maior estabilidade térmica em comparação com as quitosanas, devido à maior porcentagem de unidades GlcNAc nas suas cadeias. As características morfológicas da beta-quitina e das quitosanas foram determinadas pelo emprego da microscopia eletrônica de varredura, foi observado que as partículas das quitosanas apresentaram certa rugosidade aparente devido à ocorrência de um acentuado processo de descamação da superfície do polímero. A partir dos espectros no infravermelho foi possível identificar e diferenciar as bandas características, tanto da beta-quitina quanto das quitosanas. Os valores de grau médio de acetilação e de massa molar viscosimétrica média das amostras de quitosana variaram nos intervalos 42%&lt;<span style=\"text-decoration: overline\">GA&lt;62% e 1,25x105g.mol-1&lt;<span style=\"text-decoration: overline\">Mv&lt;2,93x105g.mol-1, respectivamente. Esses resultados revelam que o processo DAIUS foi eficiente na conversão de beta-quitina em quitosana, e que foram produzidas quitosanas com elevada massa molar viscosimétrica média, entretanto o intervalo de variação dos parâmetros do processo não resultou em variação importante do grau médio de acetilação das quitosanas produzidas. / In this project, &beta;-chitin samples extracted from squid pens were submitted to the USAD, ultrasound assisted deacetylation process aiming the production of extensively deactylated high molar mass chitosans. For that process parameters, as, diameter of the reactor, ultrasound irradiation pulsing time and pre-conditioning time seeking the swelling of the &beta;-chitin particles, they have been varied using a fractional factorial design (23-1). From this design resulted the performance of four experiments and the central point triplicate. The &beta;-chitin pattern and the obtained chitosans were characterized by 1H NMR spectroscopy, infrared spectroscopy, X-ray diffraction, capillary viscometry, scanning electron microscopy and thermogravimetry. The parameter of acetylation (PA) of the obtained chitosans was determined from the 1H NMR spectra, allowing the assessment to the distribution pattern of GlcNAc and GlcN units predominant in the chains. The chitosans presented parameter of acetylation ranging as 0,61&lt;PA&lt;0,82, indicating the predominance of random distribution of GlcNAc and GlcN units. The determination of the chitosans solubility was based on the turbidity of its solutions, all being soluble in pH &lt; 5, exept for QT2 sample that was insoluble. The &beta;-chitin showed higher thermal stability in comparisson to the chitosans, probably due to the higher content of GlcNAc units in their chains. The morphological characteristics of &beta;-chitin and chitosans were characterized by scanning electron microscopy, It was observed that the chitosans particles presented certain rugosity apparently due to the occurrence of a strong process of scaling of the polymer surface. From the infrared spectra it was possible to identify and to distinguish the characteristic bands either of the &beta;-chitin as the chitosans. The values of the average degree of acetylation and viscosity average molar mass from the chitosans samples vary in the intervals 42%&lt;<span style=\"text-decoration: overline\">GA&lt;62% e 1,25x105g.mol-1&lt;<span style=\"text-decoration: overline\">Mv&lt;2,93x105g.mol-1, respectively. These outcomes reveal that the USAD process was effective converting &beta;-chitin in chitosan and there were generated chitosans with high viscosity average molar mass, however the process parameters variation interval did not result in an important average degree of acetylation variation from the generated chitosans.

by Chan Chui Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 83-94). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Contents --- p.iv / List of Figures --- p.ix / List of Plates --- p.xi / List of Tables --- p.xii / List of Abbreviations --- p.xiv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Di(2-ethylhexyl)phthalate (DEHP) --- p.1 / Chapter 1.1.1 --- The chemical class of DEHP: Phthalate ester --- p.1 / Chapter 1.1.2 --- Characteristics of DEHP --- p.3 / Chapter 1.1.3 --- Sources of releases and environmental concentration --- p.4 / Chapter 1.1.4 --- Persistence of DEHP --- p.5 / Chapter 1.1.5 --- Routes of exposure --- p.6 / Chapter 1.1.6 --- Toxicity of DEHP --- p.7 / Chapter 1.1.6.1 --- Acute toxicity --- p.7 / Chapter 1.1.6.2 --- Chronic toxicity --- p.8 / Chapter 1.1.6.2.1 --- Adverse effects on reproduction system --- p.8 / Chapter 1.1.6.2.2 --- Carcinogenicity --- p.9 / Chapter 1.1.6.2.3 --- Developmental toxicity --- p.9 / Chapter 1.1.6.2.4 --- Endocrine disruption --- p.10 / Chapter 1.1.6.2.5 --- Hepatotoxicity --- p.10 / Chapter 1.1.7 --- Regulations --- p.10 / Chapter 1.2 --- Treatment of DEHP --- p.11 / Chapter 1.2.1 --- Conventional treatment technologies --- p.11 / Chapter 1.2.1.1 --- Physical method --- p.11 / Chapter 1.2.1.1.1 --- Adsorption --- p.11 / Chapter 1.2.1.1.2 --- Sonolysis --- p.12 / Chapter 1.2.1.2 --- Photochemical method --- p.13 / Chapter 1.2.1.2.1 --- Photocatalytic oxidation (PCO) --- p.13 / Chapter 1.2.1.3 --- Biological method --- p.13 / Chapter 1.2.1.3.1 --- Biodegradation --- p.13 / Chapter 1.2.1.3.2 --- Sewage treatment process --- p.14 / Chapter 1.2.2 --- Integrated treatment method in the present study --- p.15 / Chapter 1.2.2.1 --- Biosorption --- p.15 / Chapter 1.2.2.1.1 --- Definition of biosorption --- p.15 / Chapter 1.2.2.1.2 --- Advantages of biosorption --- p.16 / Chapter 1.2.2.1.3 --- Chitinous materials as biosorbents --- p.16 / Chapter 1.2.2.1.4 --- Advantages of using chitinous materials as biosorbents --- p.17 / Chapter 1.2.2.1.5 --- Modeling of biosorption --- p.19 / Chapter 1.2.2.2 --- PCO --- p.21 / Chapter 1.2.2.2.1 --- Definition of PCO --- p.21 / Chapter 1.2.2.2.2 --- Mechanism of PCO --- p.23 / Chapter 1.2.2.2.3 --- Advantages of PCO --- p.25 / Chapter 2 --- Objectives --- p.27 / Chapter 3 --- Materials and methods --- p.28 / Chapter 3.1 --- Materials --- p.28 / Chapter 3.1.1 --- Adsorbate --- p.28 / Chapter 3.1.2 --- Biosorbents --- p.28 / Chapter 3.1.2.1 --- Pretreatment of biosorbents --- p.29 / Chapter 3.1.3 --- Photocatalytic reactor --- p.29 / Chapter 3.1.4 --- Photocatalyst --- p.30 / Chapter 3.1.5 --- Electron scavenger --- p.31 / Chapter 3.2 --- Methods --- p.31 / Chapter 3.2.1 --- Determination of DEHP concentration --- p.31 / Chapter 3.2.2 --- Batch biosorption experiment --- p.32 / Chapter 3.2.2.1 --- Screening of biosorbents --- p.33 / Chapter 3.2.2.2 --- Optimization of biosorption conditions --- p.33 / Chapter 3.2.2.2.1 --- Effect of biosorbent concentration --- p.33 / Chapter 3.2.2.2.2 --- Effect of initial pH --- p.33 / Chapter 3.2.2.2.3 --- Effect of biosorption time --- p.34 / Chapter 3.2.2.2.4 --- Effect of temperature --- p.34 / Chapter 3.2.2.2.5 --- Effect of agitation rate --- p.34 / Chapter 3.2.2.2.6 --- Effect of initial DEHP concentration --- p.34 / Chapter 3.2.2.2.7 --- "Combinational effect of initial pH, chitin A concentration and initial DEHP concentration" --- p.35 / Chapter 3.2.3 --- Extraction of adsorbed DEHP from chitin A --- p.35 / Chapter 3.2.3.1 --- Screening of extraction agents --- p.36 / Chapter 3.2.3.2 --- Determination of extraction time --- p.36 / Chapter 3.2.4 --- Batch PCO experiment --- p.36 / Chapter 3.2.4.1 --- Optimization of PCO conditions --- p.38 / Chapter 3.2.4.1.1 --- Effect of reaction time --- p.38 / Chapter 3.2.4.1.2 --- Effect of UV-A intensity --- p.38 / Chapter 3.2.4.1.3 --- Effect of TiO2 concentration --- p.38 / Chapter 3.2.4.1.4 --- Effect of H2O2 concentration --- p.38 / Chapter 3.2.4.1.5 --- Effect of initial pH --- p.39 / Chapter 3.2.4.1.6 --- Combinational effect of H2O2 concentration and initial pH --- p.39 / Chapter 3.2.4.1.7 --- Effect of concentration factor --- p.39 / Chapter 3.2.4.2 --- Identification of intermediates/products of DEHP --- p.39 / Chapter 3.2.4.3 --- Evaluation for the toxicity of DEHP and the intermediates/products by the Microtox® test --- p.40 / Chapter 4 --- Results --- p.42 / Chapter 4.1 --- Batch biosorption experiment --- p.42 / Chapter 4.1.1 --- Screening of biosorbents --- p.42 / Chapter 4.1.2 --- Optimization of biosorption conditions --- p.42 / Chapter 4.1.2.1 --- Effect of biosorbent concentration --- p.42 / Chapter 4.1.2.2 --- Effect of initial pH --- p.42 / Chapter 4.1.2.3 --- Effect of biosorption time --- p.46 / Chapter 4.1.2.4 --- Effect of temperature --- p.46 / Chapter 4.1.2.5 --- Effect of agitation rate --- p.46 / Chapter 4.1.2.6 --- Effect of initial DEHP concentration --- p.46 / Chapter 4.1.2.7 --- "Combinational effect of initial pH, chitin A concentration and initial DEHP concentration" --- p.51 / Chapter 4.1.2.8 --- Summary of biosorption conditions before and after optimization --- p.54 / Chapter 4.2 --- Extraction of adsorbed DEHP from chitin A --- p.54 / Chapter 4.2.1 --- Screening of extraction agents --- p.54 / Chapter 4.2.2 --- Determination of extraction time --- p.55 / Chapter 4.3 --- Batch PCO experiment --- p.56 / Chapter 4.3.1 --- Optimization of PCO conditions --- p.56 / Chapter 4.3.1.1 --- Effect of reaction time --- p.56 / Chapter 4.3.1.2 --- Effect of UV-A intensity --- p.57 / Chapter 4.3.1.3 --- Effect of TiO2 concentration --- p.59 / Chapter 4.3.1.4 --- Effect of H2O2 concentration --- p.60 / Chapter 4.3.1.5 --- Effect of initial pH --- p.61 / Chapter 4.3.1.6 --- Combinational effect of H2O2 concentration and initial pH --- p.62 / Chapter 4.3.1.7 --- Effect of CF --- p.63 / Chapter 4.3.1.8 --- Summary of PCO conditions before and after optimization --- p.63 / Chapter 4.3.2 --- Identification of intermediates/products of DEHP --- p.64 / Chapter 4.3.3 --- Evaluation for the toxicity of DEHP and the intermediates/products by the Microtox® test --- p.66 / Chapter 5 --- Discussion --- p.68 / Chapter 5.1 --- Batch biosorption experiment --- p.68 / Chapter 5.1.1 --- Screening of biosorbents --- p.68 / Chapter 5.1.2 --- Optimization of biosorption conditions --- p.69 / Chapter 5.1.2.1 --- Effect of biosorbent concentration --- p.69 / Chapter 5.1.2.2 --- Effect of initial pH --- p.69 / Chapter 5.1.2.3 --- Effect of biosorption time --- p.70 / Chapter 5.1.2.4 --- Effect of temperature --- p.71 / Chapter 5.1.2.5 --- Effect of agitation rate --- p.71 / Chapter 5.1.2.6 --- Effect of initial DEHP concentration --- p.71 / Chapter 5.1.2.7 --- "Combinational effect of initial pH, chitin A concentration and initial DEHP concentration" --- p.73 / Chapter 5.2 --- Extraction of adsorbed DEHP from chitin A --- p.74 / Chapter 5.2.1 --- Screening of extraction agents --- p.74 / Chapter 5.2.2. --- Determination of extraction time --- p.74 / Chapter 5.3 --- Batch PCO experiment --- p.74 / Chapter 5.3.1 --- Optimization of PCO conditions --- p.74 / Chapter 5.3.1.1 --- Effect of reaction time --- p.74 / Chapter 5.3.1.2 --- Effect of UV-A intensity --- p.74 / Chapter 5.3.1.3 --- Effect of TiO2 concentration --- p.75 / Chapter 5.3.1.4 --- Effect of H2O2 concentration --- p.75 / Chapter 5.3.1.5 --- Effect of initial pH --- p.76 / Chapter 5.3.1.6 --- Combinational effect of H2O2 concentration and initial pH --- p.77 / Chapter 5.3.1.7 --- Effect of CF --- p.77 / Chapter 5.3.2 --- Identification of intermediates/products of DEHP --- p.78 / Chapter 5.3.3 --- Evaluation for the toxicity of DEHP and the intermediates/products by the Microtox test --- p.79 / Chapter 6 --- Conclusions --- p.80 / Chapter 7 --- References --- p.83

<div>The House Cricket (Acheta domesticus) is a promising alternative to traditional protein sources, as these insects produce over 12 times the mass of protein for a given mass of food/water when compared to cattle, while also producing lower amounts of greenhouse gases and NH3 emissions (Kim et al. 2017, Hanboonsong, Jamjanya and Durst 2013, Van Huis 2013). Additionally, previous studies have demonstrated significant emulsification and gelling properties of insect flours, such as from cricket, which has been attributed to the functional properties of the protein (Kim et al. 2017). Ground cricket flours contain significant quantities of both protein and fibrous polysaccharides, particularly chitin. Since chitin particles are also capable of preparing emulsions as a Pickering stabilizer, there remains a question on the relative role of the protein and chitin components in crickets for stabilizing emulsion products. Relative contributions of each component was identified by first isolating the water-soluble protein and water-insoluble chitin fractions from ground cricket flour and then determining their interfacial properties and stability of prepared oil-in-water emulsions. Dynamic interfacial tension measurements indicated significant surface activity of the protein fraction, while there was minimal evidence of significant surface pressure development in the presence of 5-10 μm chitin particles. 10 % (w/w) canola oil-in-water emulsions were prepared with 0.5-2% (w/w) of the water-soluble protein fraction and 5.29% (w/w) canola oil-in-water emulsions were prepared with 0.688% of the chitin fraction. Stability of the emulsions against creaming was between 75% and 90% for emulsions stabilized by the protein fraction over three weeks of storage and between 93% and 96% for emulsions stabilized by chitin over 24 hours of storage. Significant fractions of precipitate- and oil-layers found in chitin-stabilized dispersions was attributed to the presence of large chitin particles (79 μm volume weighted mean diameter) and inefficient adsorption to droplet interfaces during homogenization, respectively. Volume-weighted mean diameter of emulsified oil droplets remained at 17-24 μm among protein-stabilized (>1.5 wt%) emulsions over three weeks of storage but only 60 μm over 24 hours among chitin-stabilized emulsions. Light micrographs of emulsion droplets showed successful adsorption of chitin fractions to oil droplets in the emulsion layer, verifying their potential as Pickering stabilizers. These findings demonstrated that both water-soluble protein and chitin particles obtained from ground cricket flours are legitimate emulsion stabilizers, yet the chitin fraction is much less effective without a more intensive approach to reduce their particle size.</div>

Ng, Yiu Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 99-114). / Abstracts in English and Chinese. / Acknowledgements --- p.2 / Abstract --- p.3 / 摘要 --- p.5 / Content --- p.6 / List of abbreviations and symbols --- p.10 / Chapter Chapter 1 - --- Introduction --- p.13 / Chapter 1.1 --- Introduction to nanoparticles (NPs) --- p.13 / Chapter 1.2 --- How to treat solid cancers using nanoparticle drugs --- p.17 / Chapter 1.3 --- What is Chitosan (CS)? --- p.22 / Chapter 1.4 --- Possible peptide candidates to be trapped --- p.26 / Chapter 1.4.1 --- Luffin PI - Ribosome inactivating peptide --- p.26 / Chapter 1.4.2 --- Buforin lib (Bllb) - Antimicrobial peptide --- p.27 / Chapter 1.5 --- Aims of study --- p.30 / Chapter Chapter 2 - --- Materials and Methods --- p.31 / Chapter 2.1 --- Materials --- p.31 / Chapter 2.2 --- Methods --- p.31 / Chapter 2.2.1 --- Construction and expression of Luffin P1 --- p.31 / Chapter 2.2.2 --- Circular dichroism spectroscopy --- p.32 / Chapter 2.2.3 --- Static light scattering --- p.33 / Chapter 2.2.4 --- In vitro N-glycosidase assay --- p.34 / Chapter 2.2.5 --- Preparation of CS particles --- p.34 / Chapter 2.2.5.1 --- Preparation of positive CS NPs --- p.34 / Chapter 2.2.5.2 --- Preparation of negative CS NPs --- p.35 / Chapter 2.2.5.3 --- Preparation of buforin lib incorporated NPs --- p.35 / Chapter 2.2.5.4 --- Preparation of Cy5 incorporated NPs --- p.36 / Chapter 2.2.6 --- Characterization of CS NPs --- p.36 / Chapter 2.2.7 --- Buforin lib (Bllb) encapsulation efficiency and loading capacity --- p.36 / Chapter 2.2.8 --- In vitro release study --- p.37 / Chapter 2.2.9 --- Confocal Microscopy --- p.37 / Chapter 2.2.10 --- Cytotoxicity assay --- p.38 / Chapter 2.2.11 --- Statistical analysis --- p.38 / Chapter Chapter 3 - --- "Cloning, expression, purification and structural characterization of Luffin PI" --- p.39 / Chapter 3.1 --- Introduction --- p.39 / Chapter 3.2 --- Results --- p.41 / Chapter 3.2.1 --- Construction of Luffin PI plasmid --- p.41 / Chapter 3.2.2 --- Expression and purification of Luffin PI --- p.41 / Chapter 3.3.3 --- Molecular weight and secondary structure determination of Luffin PI --- p.43 / Chapter 3.3.4 --- 3D solution structure of Luffin PI --- p.45 / Chapter 3.3.5 --- In vitro N-glycosidase activity of Luffin PI --- p.49 / Chapter 3.3 --- Discussion --- p.51 / Chapter Chapter 4 - --- Generation of positively charged CS particles and Bllb incorporation --- p.60 / Chapter 4.1 --- Introduction --- p.60 / Chapter 4.2 --- Results --- p.62 / Chapter 4.2.1 --- Positively charged CS NPs generation --- p.62 / Chapter 4.2.2 --- Bllb incorporated +ve CS NPs generation --- p.68 / Chapter 4.2.3 --- In vitro release study --- p.70 / Chapter 4.2.4 --- In vitro cytotoxicity test --- p.72 / Chapter 4.3 --- Discussion --- p.74 / Chapter Chapter 5 - --- Generation of negatively charged CS particles and Bllb incorporation --- p.83 / Chapter 5.1 --- Introduction --- p.83 / Chapter 5.2 --- Results --- p.85 / Chapter 5.2.1 --- -ve CS NPs generation --- p.85 / Chapter 5.2.2 --- -ve CS-Bllb NPs generation --- p.88 / Chapter 5.2.3 --- In vitro release study --- p.91 / Chapter 5.2.4 --- Localization study of -ve CS-Bllb NPs --- p.93 / Chapter 5.2.5 --- In vitro cytotoxicity test --- p.96 / Chapter 5.3 --- Discussion --- p.98 / Chapter Chapter 6 - --- Conclusion and future work --- p.108 / Copyright --- p.110 / References --- p.111

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-03-26T15:15:34Z No. of bitstreams: 2 Dissertação - Jéssica Fernanda Bertolino - 2018.pdf: 1738703 bytes, checksum: 494fae0cabd867aa9612c7de9a5f3a96 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-03-27T12:09:19Z (GMT) No. of bitstreams: 2 Dissertação - Jéssica Fernanda Bertolino - 2018.pdf: 1738703 bytes, checksum: 494fae0cabd867aa9612c7de9a5f3a96 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-27T12:09:20Z (GMT). No. of bitstreams: 2 Dissertação - Jéssica Fernanda Bertolino - 2018.pdf: 1738703 bytes, checksum: 494fae0cabd867aa9612c7de9a5f3a96 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-01 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Recent researches in bioscience have been focusing in the development of biocompatible materials to replace parts or function of living organisms. Moreover, versatility, low cost and minimally tissue recctiveness are some of the major interest in biomaterial research. Several synthetic and natural resources have been developed. Biometareial components’ features and particularities must be thoroughly assessed to assure standardization and quality of the final product. The purpose of this research was to develop and assess physicochemical and biological features of a chitosan, pequi oil and gelatine based membrane for use in tissue regeneration. Components were mixed in a proportion that kept homogeneity and integrity of the membrane. Membrane’s thermal analysis, scanning electron microscopy, cytotoxicity and bactericidal/bacteriostatic and fungicidal/fungi- static features were evaluated. It was observed that the membrane presented compatible characteristics to be used in soft tissues and that there was no interaction between the components. The presence of pequi oil did not interfere in the biomaterial cytotoxicity. Tests with microorganisms revealed that there was no death or reduction of microorganism proliferation. It was concluded that the mixture of the components allows to obtain a material in the membrane format, however, new investigations are necessary to understand the mechanisms involved in the presented cytotoxicity, as well as the behavior towards the microorganisms in the presence of enzymes that degrade the material, simulating conditions of the animal organic fluid. / Nas últimas décadas houve aumento nas pesquisas para criação de materiais biocompatíveis que possam substituir parte ou função de organismos vivos, de maneira prática e de baixo custo, sem causar injúrias teciduais. O objetivo desse estudo foi o desenvolvimento, caracterização físico-química e biológica de membrana constituida por quitosana, óleo de pequi e gelatina, visando a possível utilização para auxiliar na regeneração tecidual. Para isto, foram obtidas misturas dos componentes em proporções que mantivessem o material homogêneo e não fragmentado. Para a caracterização, utilizou-se análise térmica, microscopia eletrônica de varredura, testes de citotoxicidade e atividade bactericida/bacteriostática e fungicida/fungiostática das membranas. Observou-se que a membrana apresentou características compatíveis para emprego em tecidos moles e que não houve interação química entres os componentes. A presença do óleo de pequi não interferiu na citotoxicidade do biomaterial. Os testes com microrganismos revelaram que não houve morte e nem redução da proliferação de micro-organismos. Concluiu-se que a mistura dos componentes permite a obtenção de um material no formato de membrana, no entanto são necessárias novas investigações para compreender os mecanismos envolvidos na citotoxicidade apresentada, bem como o comportamento frente aos micro-organismos na presença de enzimas que degradem o material, simulando condições do fluido orgânico animal.

Made available in DSpace on 2016-04-28T20:15:34Z (GMT). No. of bitstreams: 1 2009 - Vanessa Paulino da Cruz Vieira.pdf: 5069227 bytes, checksum: c261307b8ea09c79baed9a3f788934ca (MD5) Previous issue date: 2009-02-26 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study was realized with the objective of to evaluate the inhibitory activity of the insect growth regulator, fluazuron, on evolutive stages and adults of Ctenocephalides felis felis. Twelve beagle dogs were utilized divided into two groups of six animals on day 0 (treatment day). Group 1: Dogs were treated with a pour on formulation of 2.5% fluazuron, in the dosis of 10 mg/kg body weight and; Group 2: Dogs were maintained untreated (control). Each dog was infested with 200 specimens of C. felis felis. Reinfestations were performed on days +5, +12, +19, +26, +33, and +40. Seventy four hours after each infestation, animals were placed in individual pet transport boxes for four hours. Afterwards, the material present in the bottom of each box was collected and the found eggs were quantified. Half of the eggs were incubated with 0.5g of an artificial diet for larval maintenance in a BOD incubator in the temperature of 28?C and relative humidity of 75 ? 10%. Seven days after, the material were fixed in 70% ethanol and evaluated for larval eclosion. After 25 days, half rest were also fixed in 70% ethanol and evaluated for the emergency of adult fleas. Each dog was combed until complete removal of fleas. Thus, fleas were quantified sexed, being evaluated the interference caused by fluazuron on adult recovery, and possibly, a different effect per gender. In order to evaluate the activity of fluazuron on oviposition of C. felis felis, the ratio between egg production and number of recovered females. The efficacy of fluazuron on C. felis felis development from egg to larvae on days +8, +15, +22 and +29 was higher 80%. For the development from egg to adult, the efficacy remained above 80% for 22 days after treatment, reaching 100% on day +15. A significant aulticidal efficacy of fluazuron was observed on days +8; +22; +36 e +43. Regarding to female fleas was observed significant difference on days +8; +22 e +36 and, for males on days +8 and +36. The efficacy of fluazuron on the inhibition of oviposition did not presented significance throughout the 43 experimental days. Fluazuron has efficacy on the development from egg to larva and egg to adult of C. felis felis. However, it shows low adulticidal activity, and does not interfere on fleas?s oviposition. / Este trabalho foi realizado com o objetivo de avaliar a atividade inibit?ria do regulador de crescimento de insetos, fluazuron, sobre as formas evolutivas e adultos de Ctenocephalides felis felis. Foram utilizados 12 c?es da ra?a Beagle, e, no dia 0, dia do tratamento, foram divididos em dois grupos: Grupo 1. Seis c?es tratados com formula??o pour on , de fluazuron a 2,5 %, empregando-se a dose de 10 mg por Kg de peso corporal e Grupo 2. Seis c?es mantidos como controle, sem tratamento. Cada c?o foi infestado com 200 esp?cimes de C. felis felis. Novas infesta??es foram realizadas nos dias +5, +12, +19, +26, +33, e +40. Setenta e duas horas ap?s cada infesta??o, os c?es foram alocados em transportes para c?es, por quatro horas. Ap?s esse per?odo, o material foi coletado e os ovos quantificados. Metade dos ovos foi incubada com 0,5 grama de uma dieta para manuten??o das larvas, em c?mara climatizada mantida na temperatura de 28?C e umidade relativa de 75 ? 10%. Ap?s sete dias, o material foi fixado em ?lcool 70% e avaliado para eclos?o de larvas. Vinte cinco dias depois, a metade restante foi fixada tamb?m com ?lcool 70% e avaliada para emerg?ncia de pulgas adultas. Cada c?o foi penteado para retirada total das pulgas, que foram quantificadas e sexadas, sendo avaliada a interfer?ncia do fluazuron sobre a recupera??o de adultos e poss?vel atua??o diferenciada por sexo. Para a avalia??o da atividade do fluazuron sobre a oviposi??o de C. felis felis, foi calculada a rela??o entre a produ??o de ovos e o n?mero de f?meas recuperadas. A efic?cia do fluazuron sobre o desenvolvimento de ovo a larva de C. felis felis, nos dia +8; +15; +22 e +29, foi superior a 80%. No desenvolvimento de ovo a adulto de C. felis felis, a efic?cia permaneceu acima de 80% nos primeiros 22 dias ap?s o tratamento, e, no dia +15, o fluazuron alcan?ou 100% de efic?cia. No presente estudo, nos dias +8; +22; +36 e +43, foi constatada uma efic?cia adulticida significativa no grupo tratado com fluazuron. Em f?meas, houve diferen?a significativa nos dias +8; +22 e +36, e em machos nos dias +8 e +36. Ao longo dos 43 dias experimentais, a efic?cia do fluazuron na inibi??o da oviposi??o n?o apresentou signific?ncia. O fluazuron possui efic?cia sobre o desenvolvimento de ovo a larva e de ovo a adulto de C. felis felis. Entretanto, apresenta baixa atividade adulticida, e n?o interfere na oviposi??o das pulgas.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-04-20T11:39:08Z No. of bitstreams: 1 2012 - Vanessa Paulino da Cruz Vieira.pdf: 1181202 bytes, checksum: 7bfcf1b5c3509ddacbb033dcaf5448c3 (MD5) / Made available in DSpace on 2017-04-20T11:39:08Z (GMT). No. of bitstreams: 1 2012 - Vanessa Paulino da Cruz Vieira.pdf: 1181202 bytes, checksum: 7bfcf1b5c3509ddacbb033dcaf5448c3 (MD5) Previous issue date: 2012-03-29 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / This study was conducted to evaluate the activity of fluazuron administered orally in the control of R. sanguineus in dogs. A total of 12 beagle dogs which, on day 0, treatment day, were divided into two groups: Group 1. Six animals treated with oral formulation fluazuron at a dose rate of 20 mg / kg body weight and Group 2. Six dogs kept as control without treatment. On the same day, containment devices for ticks denim cloth were attached with glue to the back trichotomized dogs. After this procedure, three challenges were performed on days +1, +20 and +40, where the animals of both groups received infestations with the three stage of the tick R. sanguineus: approximately 2.500 larvae, 200 nymphs and 25 adult couples. Were used a climatic chamber with biochemical oxygen demand, BOD, at a temperature of 27 ? 1 ? C and relative humidity of 80 ? 10%. From the fourth to tenth day after each challenge, the devices were opened daily to the collection of engorged stages. Larvae and nymphs were counted and divided into syringes for evaluating the changes. The engorged females were collected and fixed in petri dishes to perform the posture that was weighed and placed in syringes, sealed with cotton, to calculate the hatchability. The efficacy of recovery fluazuron on larvae of A. sanguineus in dogs was 84.3% for day of challenge of the day +20 and 36% for the day +40. With regard to the recovery of engorged nymphs of R. sanguineus in dogs fluazuron achieved an efficacy of 82.4% and 51.7% on days +20 and +40. There was statistical difference between the mean number of engorged nymphs of R. sanguineus recovered on days +20 and +40 (p ? 0.05). The efficacy of recovery of the fluazuron engorged females was lower than 30.3% over the whole experimental period. The efficacy of treatment on reproductive performance of R. sanguineus was less than 12.4% in the three days of challenge. In inhibiting the change of larvae or nymphs ecdysis, fluazuron showed the effectiveness of 0%, 96.9% and 45.0% for days +1, +20 and +40, respectively. On day +20, there was a statistically significant difference between the mean engorged larvae to nymphs who underwent changes (p ? 0.05). The effectiveness of fluazuron on the inhibition of molting or ecdysis of nymphs to adults was 0%, 99.5% and 63.5% for days +1, +20 and +40, respectively, a statistically significant difference between mean the control and treated groups on days +20 and +40 (p ? 0.05). The growth regulator arthropod fluazuron is effective in helping control larvae and nymphs of R. sanguineus, when administered orally to dogs at a dose of 20mg/Kg. The same dose and route of administration, has no significant negative effect on female reproductive R. sanguineus. / O presente trabalho foi realizado com o objetivo avaliar a atividade do fluazuron administrado por via oral no controle de R. sanguineus em c?es. Foram utilizados 12 c?es da ra?a Beagle, que, no dia 0, dia do tratamento, foram divididos em dois grupos: Grupo 1. Seis c?es tratados com formula??o oral de fluazuron na dosagem de 20 mg/Kg de peso corporal e Grupo 2. Seis c?es mantidos como controle, sem tratamento. No mesmo dia, dispositivos para conten??o de ixod?deos de pano brim foram aderidos com cola ao dorso tricotomizado dos c?es. Ap?s esse procedimento, foram realizados tr?s desafios, nos dias +1, +20 e +40, onde os animais dos dois grupos receberam infesta??es com as tr?s fases do carrapato R. sanguineus: aproximadamente 2.500 larvas, 200 ninfas e 25 casais de adultos. Foi utilizada c?mara climatizada com demanda bioqu?mica de oxig?nio, tipo BOD, a uma temperatura de 27 ? 1oC e umidade relativa de 80 ? 10%. Do quarto ao d?cimo dia ap?s cada desafio, os dispositivos foram abertos diariamente para a coleta das fases ingurgitadas. As larvas e as ninfas foram contadas e separadas em seringas para a avalia??o da muda. As f?meas ingurgitadas foram coletadas e fixadas em placas de petri para realiza??o da postura que foi pesada e colocada em seringas, vedadas com algod?o, para o c?lculo da eclodibilidade. A efic?cia do fluazuron sobre a recupera??o de larvas de R. sanguineus em c?es foi de 84,3% para o desafio do dia +20 e 36% para o dia +40. Com rela??o ? recupera??o de ninfas ingurgitadas de R. sanguineus em c?es, o fluazuron obteve uma efic?cia de 82,4% e 51,7% nos dias +20 e +40. Houve diferen?a estat?stica entre os n?meros m?dios de ninfas ingurgitadas de R. sanguineus recuperadas nos dias +20 e +40 (p?0,05). A efic?cia do fluazuron sobre a recupera??o de f?meas ingurgitadas foi inferior a 30,3% durante todo o per?odo experimental. A efic?cia do tratamento sobre a efici?ncia reprodutiva de R. sanguineus se apresentou inferior a 12,4% nos tr?s dias de desafio. Na inibi??o da muda ou ecdise de larvas para ninfas, o fluazuron apresentou uma efic?cia de 0%, 96,9% e 45,0% para os dias +1, +20 e +40, respectivamente. No dia +20, observou-se diferen?a estat?stica significativa entre as m?dias de larvas ingurgitadas que realizaram muda para ninfas (p?0,05). A efic?cia do fluazuron sobre a inibi??o da muda ou ecdise de ninfas para adultos foi de 0%, 99,5% e 63,5% para os dias +1, +20 e +40, respectivamente, havendo diferen?a estat?stica significativa entre as m?dias dos grupos controle e tratado nos dias +20 e +40 (p?0,05). O regulador de crescimento de artr?podes fluazuron ? eficaz no aux?lio do controle de larvas e ninfas de R. sanguineus, quando administrado oralmente em c?es, na dose de 20mg/Kg. Na mesma dose e via de administra??o, n?o apresenta efeito negativo significativo na reprodu??o de f?meas de R. sanguineus.

Wong, Kin Shing Kinson. / Thesis submitted in: November 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 145-158). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.v / Contents --- p.viii / List of figures --- p.xv / List of plates --- p.xx / List of tables --- p.xxi / Abbreviations --- p.xxiii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Heavy metals --- p.1 / Chapter 1.1.1 --- Characteristics of heavy metals --- p.1 / Chapter 1.1.2 --- Heavy metal pollution in Hong Kong --- p.2 / Chapter 1.1.3 --- Common usage of heavy metals --- p.4 / Chapter 1.1.3.1 --- Copper --- p.4 / Chapter 1.1.3.2 --- Nickel --- p.4 / Chapter 1.1.3.3 --- Zinc --- p.5 / Chapter 1.1.4 --- Toxicity of heavy metals --- p.5 / Chapter 1.1.4.1 --- Copper --- p.6 / Chapter 1.1.4.2 --- Nickel --- p.7 / Chapter 1.1.4.3 --- Zinc --- p.7 / Chapter 1.1.5 --- Treatment techniques for metal ions --- p.8 / Chapter 1.1.5.1 --- Chemical precipitation --- p.9 / Chapter 1.1.5.2 --- Ion exchange --- p.10 / Chapter 1.1.5.3 --- Activated carbon adsorption --- p.10 / Chapter 1.2 --- Biosorption --- p.11 / Chapter 1.2.1 --- Definition of biosorption --- p.11 / Chapter 1.2.2 --- Mechanism --- p.12 / Chapter 1.2.3 --- Advantages of biosorption --- p.13 / Chapter 1.2.4 --- Selection of biosorbents --- p.15 / Chapter 1.3 --- Chitinous materials --- p.17 / Chapter 1.3.1 --- Background of chitin --- p.17 / Chapter 1.3.2 --- Structures of chitinous materials --- p.18 / Chapter 1.3.3 --- Sources of chitinous materials --- p.18 / Chapter 1.3.4 --- Application of chitinous materials --- p.20 / Chapter 1.3.5 --- Mechanism of metal ion adsorption by chitin --- p.22 / Chapter 1.4 --- Activated carbon --- p.25 / Chapter 1.4.1 --- Characteristics of activated carbon --- p.25 / Chapter 1.4.2 --- Applications of activated carbon --- p.26 / Chapter 1.4.3 --- Factors affecting adsorption ability of activated carbon --- p.27 / Chapter 1.4.4 --- Advantages and Disadvantages --- p.28 / Chapter 1.4.4.1 --- Advantages (Adsorption) --- p.28 / Chapter 1.4.4.2 --- Advantages (Regerneration) --- p.28 / Chapter 1.4.4.3 --- Disadvantages (Adsorption) --- p.28 / Chapter 1.4.4.4 --- Disadvantages (Regeneration) --- p.29 / Chapter 1.5 --- Cation exchange resin --- p.29 / Chapter 1.5.1 --- Usages of cation exchange resin --- p.29 / Chapter 1.5.2 --- Characteristics of cation exchange resin --- p.30 / Chapter 1.5.3 --- Disadvantages of using cation exchange resin --- p.30 / Chapter 1.6 --- Magnetite --- p.31 / Chapter 1.6.1 --- Reasons of using magnetite --- p.31 / Chapter 1.6.2 --- Characteristics of magnetite --- p.31 / Chapter 1.6.3 --- Immobilization by magnetite --- p.32 / Chapter 1.6.4 --- Advantages of using magnetite --- p.33 / Chapter 1.7 --- The biosorption experiment --- p.33 / Chapter 1.7.1 --- The batch biosorption experiment --- p.33 / Chapter 1.7.2 --- The adsorption isotherms --- p.34 / Chapter 1.7.2.1 --- The Langmuir adsorption isotherm --- p.34 / Chapter 1.7.2.2 --- The Freundlich adsorption isotherm --- p.36 / Chapter 2. --- Objectives --- p.38 / Chapter 3. --- Materials and methods --- p.39 / Chapter 3.1 --- Adsorbents --- p.39 / Chapter 3.1.1 --- Chitin A --- p.39 / Chapter 3.1.2 --- Pretreatment of chitin A --- p.39 / Chapter 3.1.3 --- Magnetite --- p.39 / Chapter 3.1.4 --- Activated carbon --- p.41 / Chapter 3.1.5 --- Cation exchange resin --- p.41 / Chapter 3.1.6 --- Pretreatment of cation exchange resin --- p.41 / Chapter 3.2 --- Chemicals --- p.43 / Chapter 3.2.1 --- Metal ion solution --- p.43 / Chapter 3.2.2 --- Buffer solution --- p.43 / Chapter 3.2.3 --- Standard solution --- p.43 / Chapter 3.3 --- Immobilization of chitin A by magnetite --- p.44 / Chapter 3.3.1 --- Effect of chitin A to magnetite ratio --- p.44 / Chapter 3.3.2 --- Effect of amount of chitin A and magnetite in a fixed ratio --- p.45 / Chapter 3.3.3 --- Effect of pH --- p.45 / Chapter 3.3.4 --- Effect of immobilization time --- p.46 / Chapter 3.3.5 --- Effect of temperature --- p.46 / Chapter 3.3.6 --- Effect of agitation rate --- p.46 / Chapter 3.3.7 --- Effect of salinity --- p.46 / Chapter 3.3.8 --- Mass production of magnetite-immobilized chitin A --- p.47 / Chapter 3.4 --- Batch adsorption experiment --- p.47 / Chapter 3.5 --- "Optimization of physicochemical condition on Cu2+，Ni2+ and Zn2+ adsorption by MCA, AC and CER" --- p.48 / Chapter 3.5.1 --- Effect of equilibrium pH --- p.48 / Chapter 3.5.2 --- Effect of amount of adsorbent --- p.49 / Chapter 3.5.3 --- Effect of retention time --- p.49 / Chapter 3.5.4 --- Effect of agitation rate --- p.49 / Chapter 3.5.5 --- Effect of temperature --- p.50 / Chapter 3.5.6 --- Effect of initial metal ion concentration --- p.50 / Chapter 3.5.7 --- Adsorption isotherms --- p.50 / Chapter 3.5.8 --- Dimensionless separation factor --- p.52 / Chapter 3.5.9 --- Kinetic parameters of adsorption --- p.52 / Chapter 3.5.10 --- Thermodynamic parameters of adsorption --- p.53 / Chapter 3.6 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden MCA" --- p.54 / Chapter 3.6.1 --- Performances of various solutions on metal ion recovery --- p.54 / Chapter 3.6.2 --- Multiple adsorption and desorption cycles of metal ions --- p.55 / Chapter 3.7 --- Statistical analysis of data --- p.55 / Chapter 4. --- Results --- p.56 / Chapter 4.1 --- Immobilization of chitin A by magnetite --- p.56 / Chapter 4.1.1 --- Effect of chitin A to magnetite ratio --- p.56 / Chapter 4.1.2 --- Effect of amount of chitin A and magnetite in a fixed ratio --- p.59 / Chapter 4.1.3 --- Effect of pH --- p.59 / Chapter 4.1.4 --- Effect of immobilization time --- p.59 / Chapter 4.1.5 --- Effect of temperature --- p.59 / Chapter 4.1.6 --- Effect of agitation rate --- p.64 / Chapter 4.1.7 --- Effect of salinity --- p.64 / Chapter 4.1.8 --- Mass production of magnetite-immobilized chitin A --- p.64 / Chapter 4.2 --- Batch adsorption experiment --- p.67 / Chapter 4.2.1 --- Screening of adsorbents --- p.67 / Chapter 4.3 --- "Optimization of physicochemical condition on Cu2+, Ni2+ and Zn2+ adsorption by MCA, AC and CER" --- p.70 / Chapter 4.3.1 --- Effect of equilibrium pH --- p.70 / Chapter 4.3.2 --- Effect of amount of adsorbent --- p.74 / Chapter 4.3.3 --- Effect of retention time --- p.78 / Chapter 4.3.4 --- Effect of agitation rate --- p.82 / Chapter 4.3.5 --- Effect of temperature --- p.82 / Chapter 4.3.6 --- Effect of initial metal ion concentration --- p.86 / Chapter 4.3.7 --- Summary of optimized conditions for three metal ions --- p.87 / Chapter 4.3.8 --- Cost analysis of metal ion removal by three adsorbents --- p.87 / Chapter 4.3.9 --- Performance of reference adsorbents (AC and CER) --- p.87 / Chapter 4.3.10 --- Adsorption isotherms --- p.99 / Chapter 4.3.11 --- Dimensionless separation factor --- p.103 / Chapter 4.3.12 --- Kinetic parameters of adsorption --- p.106 / Chapter 4.3.13 --- Thermodynamic parameters of adsorption --- p.113 / Chapter 4.4 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden MCA" --- p.113 / Chapter 4.4.1 --- Performances of various solutions on metal ion recovery --- p.113 / Chapter 4.4.2 --- Multiple adsorption and desorption cycles of metal ions --- p.117 / Chapter 5. --- Discussions --- p.121 / Chapter 5.1 --- Immobilization of chitin A by magnetite --- p.121 / Chapter 5.1.1 --- Effect of chitin A to magnetite ratio --- p.121 / Chapter 5.1.2 --- Effect of amount of chitin A and magnetite in a fixed ratio --- p.121 / Chapter 5.1.3 --- Effect of pH --- p.122 / Chapter 5.1.4 --- Effect of immobilization time --- p.122 / Chapter 5.1.5 --- Effect of temperature --- p.122 / Chapter 5.1.6 --- Effect of agitation rate --- p.123 / Chapter 5.1.7 --- Effect of salinity --- p.123 / Chapter 5.2 --- Batch adsorption experiment --- p.123 / Chapter 5.2.1 --- Screening of adsorbents --- p.123 / Chapter 5.3 --- "Optimization of physicochemical condition on Cu2+, Ni2+ and Zn2+ adsorption by MCA, AC and CER" --- p.124 / Chapter 5.3.1 --- Effect of equilibrium pH --- p.125 / Chapter 5.3.2 --- Effect of amount of adsorbent --- p.126 / Chapter 5.3.3 --- Effect of retention time --- p.127 / Chapter 5.3.4 --- Effect of agitation rate --- p.128 / Chapter 5.3.5 --- Effect of temperature --- p.128 / Chapter 5.3.6 --- Effect of initial metal ion concentration --- p.129 / Chapter 5.3.7 --- Summary of optimized conditions for three metal ions --- p.130 / Chapter 5.3.8 --- Cost analysis of metal ion removal by three adsorbents --- p.132 / Chapter 5.3.9 --- Performance of reference adsorbents (AC and CER) --- p.133 / Chapter 5.3.10 --- Adsorption isotherms --- p.133 / Chapter 5.3.11 --- Dimensionless separation factor --- p.135 / Chapter 5.3.12 --- Kinetic parameters of adsorption --- p.136 / Chapter 5.3.13 --- Thermodynamic parameters of adsorption --- p.139 / Chapter 5.4 --- "Recovery of Cu2+, Ni2+ and Zn2+ from metal ion-laden MCA" --- p.140 / Chapter 5.4.1 --- Performances of various solutions on metal ion recovery --- p.140 / Chapter 5.4.2 --- Multiple adsorption and desorption cycles of metal ions --- p.141 / Chapter 6. --- Conclusions --- p.143 / Chapter 7. --- References --- p.145

The potential value of the chitin biomass (e.g. food waste) is recently considered being ignored by landfill. Chitin can be a potential cheap carbon source for converting into value-added chemicals by microorganisms. Serratia marcescens is a chitinolytic bacterium that harbors endogenous chitinase systems. With goals of characterzing S. marcescens chitinolytic capabilities and applying S. marcescens to chemical production from chitin, my dissertation main content includes five chapters: 1) Chapter 1 highlights background information of chitin source, S. marcescens and potential metabolic engineering targets using chitin as a substrate; 2) Chapter 2 demonstrates that ChiR is a key regulator in regulating 9 chitinase-related genes in S. marcescens Db11 and manipulation of chiR can be a useful and efficient genetic target to enhance chitin utilization; 3) Chapter 3 reports the production of N-acetylneuraminic acid (Neu5Ac) from chitin by a bottom-up approach of engineering the nonconventional chitinolytic bacterium, Serratia marcescens, including native constitutive promoter characterization and transcriptional and translational pathway balancing; 4) Chapter 4 describes improvement of S. marcescens chitinolytic capability by an adaptive evolution approach; 5) Chapter 5 elucidates S. marcescens intracellular metabolite profile using a constraint-based genome-scale metabolic model (iSR929) based on genomic annotation of S. marcescens Db11. Overall, the dissertation work is the first report of demonstrating the concept of chitin-based CBP using S. marcescens and the computational model and genetic molecular tools developed in this dissertation are valuable but not limited to design-build-test of S. marcescens for contributing to the field of biological science and metabolic engineering applications.