Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The need for a cost-effective and environmentally friendly substitute for fossil fuels has resulted in significant attention to the production of bioethanol. Lignocellulose being the most abundant renewable resource on the planet consists of cellulose, hemicelluloses and lignin. It can be exploited as a source of fermentable sugars for the conversion to ethanol which may serve as the ultimate fossil fuel replacement. Hemicelluloses, contributing one third of lignocellulose, consists of xylan and mannan. Mannan consists of glucomannan, galactomannan and galactoglucomannan. A cocktail of enzymes are required for its complete hydrolysis, including β-mannanase, β-mannosidase, α-galactosidase, β-glucosidase and acetyl-mannan esterases. A need has arisen for the development of a recombinant microorganism capable of converting lignocelluloses to bioethanol through an economically feasible process. The yeast Saccharomyces cerevisiae naturally ferments hexose sugars into ethanol and has been used in various industrial applications due to its robustness in industrial processes, its well-developed expression systems, its frequent use as a model organism for heterologous gene expression and its current GRAS (Generally Regarded As Safe) status. This yeast is unable to naturally utilise complex lignocelluloses. Recombinant biotechnology can be implemented to overcome this limiting factor. Due to certain restraints by the yeast S. cerevisiae such as hyperglycosylation and poor secretion capacity, alternative hosts such as Aspergillus niger has also been considered for heterologous protein production. The Aspergillus aculeatus β-mannanase (man1) and Talaromyces emersonii α-galactosidase (Agal) genes were expressed in S. cerevisiae Y294. The cDNA of A. niger β-mannosidase (cAnmndA) and synthetic Cellvibrio mixtus β-mannosidase (CmMan5A) were expressed in A. niger. The sequence coding for the native secretion signal from CmMan5A was removed and replaced with the XYNSEC sequence (yielding XYNSEC-CmMan5A) and expressed in E. coli DH5α. The recombinant Man1, Agal, cAnmndA, CmMan5A and XYNSEC-CmMan5A displayed optimal pH of 5.47, 2.37, 3.4, 3.4 and 5.47, respectively, and optimal temperatures of 70°C for Man1, Agal, cAnmndA and CmMan5A and 50°C for XYNSEC-CmMan5A. Activity levels of Man1, Agal, cAnmndA, CmMan5A and XYNSEC-CmMan5A peaked at 36.08, 256.83, 11.61, 7.58 and 2.14 nkat/ml, respectively. Co-expression of Agal and man1 led to a decrease in enzyme secretion and therefore individual expression of these genes should be considered rather than co-expression. The enzymatic activity of Man1, Agal and CmMan5A resulted in a significant decrease in the viscosity of galactomannan when used synergistically. This study confirmed successful production of galactomannan hydrolysing enzymes by the yeast S. cerevisiae and the fungus A. niger, as well as providing insight into the synergistic effect of these enzymes on the viscosity of galactomannan. / AFRIKAANSE OPSOMMING: Die behoefte vir 'n koste-effektiewe en omgewingsvriendelike plaasvervanger vir fossielbrandstowwe het tot 'n beduidende belangstelling in die produksie van bio-etanol gelei. Lignosellulose synde die volopste hernubare hulpbron op die planeet bestaan uit sellulose, hemiselluloses en lignien. Dit kan as 'n bron van fermenteerbare suikers vir die omskakeling na etanol benut word, wat kan dien vir uiteindelike fossielbrandstofvervanging. Hemiselluloses, wat bydra tot 'n derde van lignosellulose, bestaan uit xilaan en mannaan. Mannaan bestaan uit glukomannaan, galaktomannaan en galaktoglukomannaan. 'n Mengsel van ensieme word vir die volledige hidroliese van mannaan benodig, insluitende β-mannanase, β-mannosidase, α-galaktosidase, β-glukosidase en asetiel-mannaan esterases. 'n Behoefte bestaan vir die ontwikkeling van 'n rekombinante mikroörganisme wat in staat is tot die omskakeling van lignoselluloses na bio-etanol deur middel van 'n ekonomies lewensvatbare proses. Die gis Saccharomyces cerevisiae kan heksoe suikers na etanol omskakel en word gebruik in verskeie industriële toepassings as gevolg van sy robuustheid in industriële prosesse, goed ontwikkelde uitdrukking sisteme, gereelde gebruik as 'n model-organisme vir heteroloë uitdrukking van gene en huidige GRAS (Generally Regarded As Safe) status. Die gis is nie daartoe in staat om komplekse lignosellulose te benut nie. Rekombinante biotegnologie kan egter geïmplementeer word om hierdie beperkende faktor te oorkom. As gevolg van sekere beperkinge van die gis S. cerevisiae soos hiperglikosilering en lae sekresie kapasiteit, is alternatiewe gashere soos Aspergillus niger ook oorweeg vir heteroloë proteïenproduksie. Die Aspergillus aculeatus β-mannanase (man1) en Talaromyces emersonii α-galaktosidase (Agal) gene is in S. cerevisiae Y294 uitgedruk. Die cDNA van A. niger β-mannosidase (cAnmndA) en sintetiese Cellvibrio mixtus β-mannosidase (CmMan5A) is in A. niger uitgedruk. Die DNA volgorde wat kodeer vir die natuurlike sekresiesein van CmMan5A is verwyder en vervang met die XYNSEC volgorde (gegewe XYNSEC-CmMan5A) en uitgedruk in E. coli DH5α. Die rekombinante Man1, Agal, cAnmndA, CmMan5A en XYNSEC-CmMan5A vertoon optimale pH kondisies van 5.47, 2.37, 3.4, 3.4 en 5.47, onderskeidelik, en die optimale temperatuur van 70°C vir Man1, Agal, cAnmndA en CmMan5A en 50°C vir XYNSEC-CmMan5A. Aktiwiteitsvlakke van Man1, Agal, cAnmndA, CmMan5A en XYNSEC-CmMan5A het 'n maksimum bereik op 36.08, 256.83, 11.61, 7.58 en 2.14 nkat/ml, onderskeidelik. Gesamentlike uitdrukking van Agal en man1 het tot 'n afname in ensiemsekresie gelei en dus moet individuele uitdrukking van hierdie gene eerder as gesamentlike-uitdrukking oorweeg word. Die ensiematiese aktiwiteite van Man1, Agal en CmMan5A het tot 'n beduidende afname in die viskositeit van galaktomannaan gelei wanneer dit sinergisties gebruik word. Hierdie studie bevestig suksesvolle produksie van galaktomannaan hidrolitiese ensieme in die gis S. cerevisiae en die fungus A. niger, en verskaf insig in die sinergistiese effek van hierdie ensieme op die viskositeit van galaktomannaan.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Nos Ãltimos anos, um grande interesse na associaÃÃo de materiais magnÃticos e biolÃgicos tem sido relatado na literatura. A obtenÃÃo de novos compÃsitos constituÃdos de galactomanana (GM), nanopartÃculas magnÃticas (MNPs) de NiZn e glicerol (GL) foram produzidos em diferentes proporÃÃes com finalidade de potencializar as caracterÃsticas individuais de cada material para futuras aplicaÃÃes. Sendo assim, as propriedades estruturais, magnÃticas e dielÃtricas dos nanobiocompÃsitos foram investigadas por DifraÃÃo de Raios-X (DRX), Espectroscopia de AbsorÃÃo na RegiÃo de Infravermelho (FTIR), AnÃlise TÃrmica (TG), Calorimetria ExploratÃria Diferencial (DSC), Microscopia EletrÃnica de Varredura (MEV), Microscopia EletrÃnica de TransmissÃo (TEM), Medidas MagnÃticas e Medidas DielÃtricas. A estrutura de espinÃlio da ferrita de NiZn foi confirmada por DRX e TEM e a amostra GMGL apesar de ser um material amorfo apresentou em seus nanobiocompÃsitos picos caracteristicos da fase de NiZn. As bandas caracterÃsticas para as amostras foram confirmadas por FTIR. Estas por sua vez seguiram um perfil de degradaÃÃo de acordo com as quantidades de NiZn incorporados, confirmados nos termogramas de DSC. A caracterizaÃÃo por MEV foi importante para avaliaÃÃo da morfologia. Os resultados das medidas dielÃtricas apresentaram baixas perdas dielÃtricas e das medidas magnÃticas mostraram comportamento magnÃtico para todos os nanobiocompÃsitos. Portanto, os resultados da caracterizaÃÃo dos nanobiocompÃsitos foram satisfatÃrios para possÃveis aplicaÃÃes como biomaterias, dispositivos eletrÃnicos ou em Ãreas afins. / In recent years, a great interest in the association of magnetic and biological materials has been reported in the literature. New composite consisting of galactomannan (GM), magnetic nanoparticles (NPs) of NiZn and glycerol (GL) were produced in different proportions with the purpose of enhancing the individual characteristics of each material for future applications. Thus, the structural, magnetic and dielectric properties of nanobiocomposites were investigated by Absorption Spectroscopy in the Region of Infrared (FTIR), X-Ray Diffraction (XRD), Thermal Analysis (TG), Differential Scanning Calorimetry (DSC), Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Magnetic Measurements and Dielectric Measurements. The structure of spinel NiZn ferrite was confirmed by XRD and TEM. Sample GMGL despite being an amorphous material presented in their nanobiocomposites characteristic peaks of phase NiZn. The characteristic bands in the samples were confirmed by FTIR. These in turn followed a degradation profile in accordance with the amounts of NiZn incorporated, which was confirmed in the DSC thermograms. The characterization by SEM was important to assess the morphology. The results of dielectric measurements showed low dielectric loss and magnetic measurements showed magnetic behavior for all nanobiocomposites. Therefore, the results of the characterization of nanobiocomposites were satisfactory for potential applications as biomaterials, electronic devices or related areas.

This work seeks to develop a bionanocompÃsito drawn from galactomannan and crystals nanocelulose, both obtained from Prosopis juliflora. Initially, carob pods were subjected to grinding, milling, heating, filtration and centrifugation in order to yield a viscous solution which, with the addition of ethanol, the precipitate was possible galactomannan. So all fractions, and galactomannan fiber capsules were separated. The gum obtained was lyophilized and characterized, as its composition, as well as the fibrous fractions. Further, the fibers of the capsules underwent the hydrothermal process mesquite, followed by a bleaching with H2O2 and NaOH solutions) and acidic hydrolysis (H2SO4 60% v / v) for extracting nanocelulose. After hydrolysis one estÃvl suspension nanocelulose characterized by TGA, XRD, FTIR and zeta potential was obtained. Then galactomannan films were prepared, starting from a 5% (w / v) polysaccharide solution using glycerol as plasticizer. Movies, nanocelulose were added at concentrations of 3, 5 and 7%, and evaluated the influence of the addition of the nanocrystals in the mechanical, thermal and barrier properties to water vapor. The galactomannan extracted from mesquite presented, respectively, in protein, lipid, ash and moisture content of 5.3%, 2.3%, 4.0% and 5.2% and characteristic thermal behavior, showing exothermic event to 284.7  C, typical of his degradation. Their functional groups identified by FTIR, and determination of its mass and molar ratio mannose / galactose. The fiber showed considerable differences in their levels of cellulose, hemicellulose, lignin, insoluble lignin, extractives, ash and moisture, after treatments. These results were corroborated by analysis of FTIR, XRD and TGA. And through the characterizations of the films, it was proved that there were improvements in the thermal, mechanical and barrier properties, the obtained biocomposites, with the addition of nanocelulose. / Este trabalho busca o desenvolvimento de um bionanocompÃsito elaborado a partir de galactomanana e cristais de nanocelulose, ambos obtidos da algaroba (Prosopis juliflora). Inicialmente, vagens da algaroba foram submetidas à trituraÃÃo, moagem, aquecimento, filtraÃÃo e centrifugaÃÃo obtendo-se uma soluÃÃo viscosa onde, com a adiÃÃo de etanol, foi possÃvel precipitar a galactomanana. EntÃo as fraÃÃes de interesse, galactomanana e fibra das cÃpsulas, foram separadas. A goma obtida foi liofilizada e caracterizada, quanto a sua composiÃÃo, assim como as fraÃÃes fibrosas. Na sequÃncia, as fibras das cÃpsulas da algaroba sofreram processo hidrotÃrmico, seguido de dois branqueamentos com soluÃÃes de NaOH e H2O2, e hidrÃlise Ãcida (H2SO4 60% v/v) para extraÃÃo de nanocelulose. ApÃs a hidrÃlise, foi obtida uma suspensÃo estÃvel de nanocelulose, caracterizada por TGA, DRX, potencial zeta e FTIR. EntÃo foram preparados filmes de galactomanana, a partir de uma soluÃÃo 5% (m/v) do polissacarÃdeo, utilizando glicerol como plastificante. Aos filmes, foram adicionados nanocelulose, nas concentraÃÃes de 3, 5 e 7%, e avaliado a influÃncia da adiÃÃo dos nanocristais nas propriedades mecÃnicas, tÃrmicas e de barreira a vapor de Ãgua. A galactomanana extraÃda da algaroba apresentou, respectivamente, teores de proteÃna, lipÃdio, cinzas e umidade de 5,3%, 2,3%, 4,0% e 5,2% e comportamento tÃrmico caracterÃstico, apresentando evento exotÃrmico a 284,7ÂC, tÃpico de sua degradaÃÃo. Seus grupos funcionais identificados por FTIR, alÃm da determinaÃÃo de sua massa molar e razÃo manose/galactose. A fibra apresentou considerÃveis diferenÃas nos seus teores de celulose, hemicelulose, lignina solÃvel, lignina insolÃvel, extrativos, cinzas e umidade, apÃs os tratamentos. Esses resultados foram corroborados por anÃlises de FTIR, DRX e TGA. AtravÃs das caracterizaÃÃes dos filmes, ficou comprovado que a adiÃÃo de nanocelulose melhorou propriedades tÃrmicas, mecÃnicas e de barreira, dos biocompÃsitos obtidos.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Devido Ãs suas diferentes propriedades quÃmicas tais como capacidade de formar soluÃÃes viscosas ou gÃis em meio aquoso o isolamento e caracterizaÃÃo de galactomananas tÃm sido de grande importÃncia Nesse trabalho a galactomanana do endosperma da semente de Bauhinia pentandra foi isolada e caracterizada, apresentando-se homogÃnea por GPC Este polissacarideo foi demonstrado ser uma galactomanana clÃssica formada por uma cadeia linear de manose unidas por ligaÃÃes β(1-4) com substituiÃÃes de galactose em ligaÃÃo α(1-6) com uma proporÃÃo Man:Gal de 2 5.1 e viscosidade intrÃnseca em Ãgua de 10 1 dL/g A galactomanana foi avaliada quanto à capacidade de interagir com lectinas galactose ligante O polissacarÃdeo foi tratado com epicloridrina e o material obtido foi utilizado para a montagem de coluna cromatogrÃfica de afinidade Extratos ricos em lectinas de Artocarpus incisa Artocarpus integrifÃlia e Bauhinia pentandra foram aplicados e fraÃÃes lectinicas purificadas foram obtidas A capacidade da galactomanana de B. pentandra em reter a lectina (LBp) da mesma semente foi comparada com a matriz de galactomanana de Adenantera pavonina Caesalpinea pulcherrima Sophora japonica e com a matriz comercial Sepharose 4B Apesar da galactomanana de B. pentandra ter apresentado a menor capacidade de retenÃÃo frente Ãs demais, ela mostrou-se semelhante à matriz comercial sendo viÃvel a sua utilizaÃÃo / Due the chemicals properties diferences, such as the ability to make viscous solution or aqueous gels, the study of the galactomanans has been too important. In this study, the endospermic galactomannans from seeds of Bauhinia pentandra was isolated and partially characterized. This polysaccharide is a classical galalactomannan constituted by a linear chain of mannose linked by β(1-4) linkages with galactose substituintions linked by α(1-6) linkages, resulting in a Man:Gal ratio of 2.5:1, and water intrinsic viscosity equal to 10.1 dL/g. Galactomannan was evaluated in ability to interact with galactose-binding lectins. The polysaccharide was treated with epichlorohidrine and the material obtained was utilized to make the affinity chromatography matrix. Lectin-rich extracts from Artocarpus incisa, Artocarpus integrifolia and Bauhinia pentandra were applied and lectin fractions were obtained, thus, the affinity matrix showed to be efficient to isolate them. The retention capacity of the galactomannan from B. pentandra was compared with galactomannan matrix from Adenantera pavonina, Caesalpinea pulcherrima, Sophora japonica and commercial matrix of Sepharose 4B in regards to the isolation of the lectin from B. pentandra (LBp). Although the galactomannan matrix had been showed the smallest retention capacity in comparision with the others, it is equivalent to the commercial matrix, enabling your utilization

Diese Arbeit untersucht das Auftreten falschpositiver Mannan- und Galactomannanergebnisse bei hämatologischen Patienten nach allogener Stammzelltransplantation, die parenteral ernährt werden müssen oder eine antibiotische Therapie mit Piperacillin-Tazobactam erhalten. Die Kenntnis von Quellen, die die Spezifität des Platelia™ Candida Ag plus und den Platelia™ Aspergillus EIA beeinflussen, ist ein wichtiger Beitrag zur Diagnostik systemischer Pilzinfektionen. / This study investigates the occurrence of false-positive mannan and galactomannan results in hematological patients undergoing allogeneic hematopoietic cell transplantation with current parenteral nutrition or antibiotic treatment with piperacillin-tazobactam. The knowledge of sources influencing specificity of Platelia™ Candida Ag plus and Platelia™ Aspergillus EIA contributes to the diagnosis of invasive fungal infections.

MESQUITA, Ricardy Leonam Pontes. Síntese de nanopartículas de prata através de ultrassom utilizando galactomanana. 2016. 94 f. Dissertação (Mestrado em química)- Universidade Federal do Ceará, Fortaleza-CE, 2016. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-28T17:12:54Z No. of bitstreams: 1 2016_dis_rlpmesquita.pdf: 2439147 bytes, checksum: 18f53a2e3356343fac06a5df49665f6e (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-08-02T14:38:19Z (GMT) No. of bitstreams: 1 2016_dis_rlpmesquita.pdf: 2439147 bytes, checksum: 18f53a2e3356343fac06a5df49665f6e (MD5) / Made available in DSpace on 2016-08-02T14:38:19Z (GMT). No. of bitstreams: 1 2016_dis_rlpmesquita.pdf: 2439147 bytes, checksum: 18f53a2e3356343fac06a5df49665f6e (MD5) Previous issue date: 2016 / Silver nanoparticles (NPAg) have attracted considerable interest in the context of research in recent years due to numerous applications, such as a bactericide, sensors and catalysts. In this paper the use of galactomannan of fava danta (GFD) in obtaining NPAg by ultrasonic method was studied based on the principles of green chemistry without the use of conventional chemical reducing agent. This study aimed to evaluate the ultrasound employment in NPAg synthesis GFD solutions. The NPAg were obtained with the aid of an ultrasonic probe using AgNO3 aqueous solution in concentrations of 10, 40 and 100 mmol / L. The galactomannan in aqueous solution (0,032%, 0,32% and 0,0032% w/ v) was used as stabilizer of NPAg. The synthesis occurred at varying pH (10, 11, 12) and temperature (15, 25 and 35 °C). The characterizations were performed using techniques such as gel permeation chromatography (GPC), nuclear magnetic resonance of hydrogen (NMR1H), spectrophotometry UV-Vis, dynamic light scattering (DLS) and scanning electron microscopy (SEM). UV-Vis analysis for colloids formed during the synthesis at the three concentrations showed the emergence of the plasmon band (around 400 nm) suggesting the formation of NPAg. It was observed faster kinetic profile for concentration systems 10 mmol/ L AgNO3. The pH 11 and 12 provided the best conditions for synthesis of NPAg. The different concentrations of synthetic GFD showed satisfactory results, but the formed colloid concentration 0,0032% w/ v showed no stability. Two of the synthesized colloids were selected FDAg 10/12/25 and FDAg 100/12/25, to submit the study to estimate size during the time of formation of NPAg as were also objects of analysis by electron microscopy scan. DLS was evidenced by the two colloids have decreased the size NPAg during the synthesis time, reaching average sizes near 10 to 4 nm for FDAg 10/12/25 and FDAg 100/12/25 respectively. Monitoring the polysaccharide degradation by GPC analysis was conducted and it was observed the decrease in distribution of the molar masses of the same of 6,65 x 106 to 3,11 x 104 g/ mol during the degradation process. The mannose/ galactose ratio was observed for the GFD, from 1:1,23 to GFD unmodified to 1:2,14 for the GFD degraded in 420 minutes. Thus, this study showed that the ultrasonic path in conjunction with the use of the galactomannan of fava danta in aqueous solution provides a versatile synthetic route for NPAg with good stability. / Nanopartículas de prata (NPAg) têm atraído bastante interesse no âmbito da pesquisa durante os últimos anos devido às inúmeras aplicações, tais como agente bactericida, sensores e catalisadores. Neste trabalho o uso de galactomanana da fava danta (GFD) na obtenção das NPAg por método ultrassônico foi estudado com base nos princípios da química verde sem a utilização de redutores químicos convencionais. Este estudo teve como objetivo, avaliar o emprego do ultrassom na síntese de NPAg em soluções de GFD. As NPAg foram obtidas com auxílio de uma sonda ultrassônica, utilizando solução aquosa de AgNO3 nas concentrações 10, 40 e 100 mmol/L. A galactomanana em solução aquosa (0,032%, 0,32% e 0,0032% m/v) foi utilizada como estabilizante das NPAg. As sínteses ocorreram com variação de pH (10, 11 e 12) e de temperatura (15, 25 e 35 °C). As caracterizações foram realizadas através de técnicas como Cromatografia de permeação em gel (GPC), Ressonância magnética nuclear de hidrogênio (RMN 1H), Espectrofotometria UV-Vis, Espalhamento de luz dinâmico (DLS) e Microscopia eletrônica de varredura (MEV). As análises de UV-Vis para os coloides formados durante as sínteses nas três concentrações mostraram o surgimento da banda de plasmon (em torno de 400 nm) evidenciando a formação das NPAg. Observou-se perfil cinético mais rápido para os sistemas de concentração 10 mmol/L de AgNO3. Os valores de pH 11 e 12 proporcionaram as melhores condições de síntese das NPAg. As diferentes concentrações de GFD apresentaram resultados de síntese satisfatórios, porém o coloide formado em concentração 0,0032% m/v não apresentou estabilidade. Dois dos coloides sintetizados foram selecionados, FDAg 10/12/25 e FDAg 100/12/25, a se submeterem a estudo para estimativa de tamanho durante todo o tempo de formação das NPAg, assim como também foram objetos de análise por Microscopia eletrônica de varredura. Por DLS foi evidenciado que os dois coloides tiveram diminuição de tamanho das NPAg no decorrer do tempo de síntese, atingindo tamanhos médios próximos de 10 e 4 nm para FDAg 10/12/25 e FDAg 100/12/25 respectivamente. Foi realizado o acompanhamento da degradação do polissacarídeo através de análise por GPC, tendo sido observado a diminuição da distribuição das massas molares do mesmo de 6,65 x 106 para 3,11 x 104 g/mol durante o processo de degradação. A razão manose/galactose foi verificada para a GFD, passando de 1:1,23 para a GFD não modificada para 1:2,14 para a GFD degradada em 420 minutos. Sendo assim, este estudo mostrou que a via ultrassônica em conjunto com a utilização da galactomanana da fava danta em solução aquosa proporciona uma rota sintética bastante versátil para as NPAg com boa estabilização.

Universidade Federal do Cearà / Silver nanoparticles (NPAg) have attracted considerable interest in the context of research in recent years due to numerous applications, such as a bactericide, sensors and catalysts. In this paper the use of galactomannan of fava danta (GFD) in obtaining NPAg by ultrasonic method was studied based on the principles of green chemistry without the use of conventional chemical reducing agent. This study aimed to evaluate the ultrasound employment in NPAg synthesis GFD solutions. The NPAg were obtained with the aid of an ultrasonic probe using AgNO3 aqueous solution in concentrations of 10, 40 and 100 mmol / L. The galactomannan in aqueous solution (0,032%, 0,32% and 0,0032% w/ v) was used as stabilizer of NPAg. The synthesis occurred at varying pH (10, 11, 12) and temperature (15, 25 and 35 ÂC). The characterizations were performed using techniques such as gel permeation chromatography (GPC), nuclear magnetic resonance of hydrogen (NMR1H), spectrophotometry UV-Vis, dynamic light scattering (DLS) and scanning electron microscopy (SEM). UV-Vis analysis for colloids formed during the synthesis at the three concentrations showed the emergence of the plasmon band (around 400 nm) suggesting the formation of NPAg. It was observed faster kinetic profile for concentration systems 10 mmol/ L AgNO3. The pH 11 and 12 provided the best conditions for synthesis of NPAg. The different concentrations of synthetic GFD showed satisfactory results, but the formed colloid concentration 0,0032% w/ v showed no stability. Two of the synthesized colloids were selected FDAg 10/12/25 and FDAg 100/12/25, to submit the study to estimate size during the time of formation of NPAg as were also objects of analysis by electron microscopy scan. DLS was evidenced by the two colloids have decreased the size NPAg during the synthesis time, reaching average sizes near 10 to 4 nm for FDAg 10/12/25 and FDAg 100/12/25 respectively. Monitoring the polysaccharide degradation by GPC analysis was conducted and it was observed the decrease in distribution of the molar masses of the same of 6,65 x 106 to 3,11 x 104 g/ mol during the degradation process. The mannose/ galactose ratio was observed for the GFD, from 1:1,23 to GFD unmodified to 1:2,14 for the GFD degraded in 420 minutes. Thus, this study showed that the ultrasonic path in conjunction with the use of the galactomannan of fava danta in aqueous solution provides a versatile synthetic route for NPAg with good stability. / NanopartÃculas de prata (NPAg) tÃm atraÃdo bastante interesse no Ãmbito da pesquisa durante os Ãltimos anos devido Ãs inÃmeras aplicaÃÃes, tais como agente bactericida, sensores e catalisadores. Neste trabalho o uso de galactomanana da fava danta (GFD) na obtenÃÃo das NPAg por mÃtodo ultrassÃnico foi estudado com base nos princÃpios da quÃmica verde sem a utilizaÃÃo de redutores quÃmicos convencionais. Este estudo teve como objetivo, avaliar o emprego do ultrassom na sÃntese de NPAg em soluÃÃes de GFD. As NPAg foram obtidas com auxÃlio de uma sonda ultrassÃnica, utilizando soluÃÃo aquosa de AgNO3 nas concentraÃÃes 10, 40 e 100 mmol/L. A galactomanana em soluÃÃo aquosa (0,032%, 0,32% e 0,0032% m/v) foi utilizada como estabilizante das NPAg. As sÃnteses ocorreram com variaÃÃo de pH (10, 11 e 12) e de temperatura (15, 25 e 35 ÂC). As caracterizaÃÃes foram realizadas atravÃs de tÃcnicas como Cromatografia de permeaÃÃo em gel (GPC), RessonÃncia magnÃtica nuclear de hidrogÃnio (RMN 1H), Espectrofotometria UV-Vis, Espalhamento de luz dinÃmico (DLS) e Microscopia eletrÃnica de varredura (MEV). As anÃlises de UV-Vis para os coloides formados durante as sÃnteses nas trÃs concentraÃÃes mostraram o surgimento da banda de plasmon (em torno de 400 nm) evidenciando a formaÃÃo das NPAg. Observou-se perfil cinÃtico mais rÃpido para os sistemas de concentraÃÃo 10 mmol/L de AgNO3. Os valores de pH 11 e 12 proporcionaram as melhores condiÃÃes de sÃntese das NPAg. As diferentes concentraÃÃes de GFD apresentaram resultados de sÃntese satisfatÃrios, porÃm o coloide formado em concentraÃÃo 0,0032% m/v nÃo apresentou estabilidade. Dois dos coloides sintetizados foram selecionados, FDAg 10/12/25 e FDAg 100/12/25, a se submeterem a estudo para estimativa de tamanho durante todo o tempo de formaÃÃo das NPAg, assim como tambÃm foram objetos de anÃlise por Microscopia eletrÃnica de varredura. Por DLS foi evidenciado que os dois coloides tiveram diminuiÃÃo de tamanho das NPAg no decorrer do tempo de sÃntese, atingindo tamanhos mÃdios prÃximos de 10 e 4 nm para FDAg 10/12/25 e FDAg 100/12/25 respectivamente. Foi realizado o acompanhamento da degradaÃÃo do polissacarÃdeo atravÃs de anÃlise por GPC, tendo sido observado a diminuiÃÃo da distribuiÃÃo das massas molares do mesmo de 6,65 x 106 para 3,11 x 104 g/mol durante o processo de degradaÃÃo. A razÃo manose/galactose foi verificada para a GFD, passando de 1:1,23 para a GFD nÃo modificada para 1:2,14 para a GFD degradada em 420 minutos. Sendo assim, este estudo mostrou que a via ultrassÃnica em conjunto com a utilizaÃÃo da galactomanana da fava danta em soluÃÃo aquosa proporciona uma rota sintÃtica bastante versÃtil para as NPAg com boa estabilizaÃÃo.

Orientador: Marcos Silveira Buckeridge / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-12T18:38:24Z (GMT). No. of bitstreams: 1 Lisboa_CesarGustavoSerafim_D.pdf: 1945488 bytes, checksum: 831197d663c65044a02bdfd7ba13598f (MD5) Previous issue date: 2008 / Resumo: Aplicações biotecnológicas de polissacarídeos de plantas: uma estratégia sustentável para a produção em demanda. Atualmente, a busca por novas fontes de materiais pode levar ao depósito de patentes. Isto é importante para que novos produtos, que apresentem características inovadoras, potencial de redução de custos, rotas de produção ambientalmente corretas, partição de benefícios e, finalmente, possibilitem a exploração de novos mercados de maneira sustentável. Nesse contexto, o presente trabalho teve como objetivo avaliar o potencial de uso de polissacarídeos de plantas de diferentes fontes nos setores de alimentos, farmacosméticos e papel. Os resultados são apresentados na forma de um artigo e 4 patentes. Os xiloglucanos de sementes de espécies nativas de plantas (Hymenaea courbaril) e de plântulas de eucalipto foram aplicados no processo de confecção do papel, demonstrando que suas propriedades mecânicas podem ser melhoradas. Resultados similares foram obtidos com galactomananos de sementes de Sesbania virgata e Dimorphandra mollis. O xiloglucano de H. courbaril foi estudado mais profundamente e demonstrou-se que pode ser também aplicado em cosméticos, pois não é citotóxico, é capaz de espessar formulações e interfere na produção de colágeno pela pele. As propriedades reológicas do galactomanano de D. mollis foram estudadas em comparação a outros galactomananos já utilizados na indústria. Demonstrou-se que ele é apropriado para várias aplicações em alimentos. Como um todo, nossos resultados indicam que tanto os polissacarídeos de sementes de espécies nativas como o de eucalipto podem ser utilizados em várias aplicações de tal forma que possam fazer parte de programas de uso sustentável da biodiversidade, levando a benefícios tecnológicos e também sociais. / Abstract: Biotechnological applications of plant polysaccharides: a sutainable strategy for production and demand. Nowdays, the search for new sources of materials can lead to new patent deposits. This is important because new products that display innovative features, cost reduction potential, environmentally clean production routes, partition of benefits and finally, may turn possible to explore differential market shares. These may be excellent socio-environmental and market shares for biotechnology companies. In this context, the present work aimed at evaluating the potential of use of plant polysaccharides from different sources in the food, farmacosmetic and paper industrial sectors. In the present work, we present studies that focus on the use of seed polysaccharides on applications on paper, cosmetics and food industries. The results are presented in the form of one article and 4 patents. The xyloglucan from seeds of native tropical tree species (Hymenaea courbaril - jatobá, Copaifera langsdorffii - copaiba) and from seedlings of Eucalyptus grandis (eucalypt) were applied to paper making and we demonstrated that several properties of paper can be improved by using these xyloglucans during preparation. Similar results were obtained with galactomann ans from Sesbania virgata and Dimorphandra mollis, two fast-growing legume trees. The polymers increased paper resistance to mechanical stress so that they can be applied for applications where more resistant papers (such as rapping paper) are used. The xyloglucan from H. courbaril was studied more deeply, demonstrating that it can be applied in cosmetics as it is not cytotoxic and can be used to improve skin biochemistry such as collagen production. Galactomannan from D. mollis was studied from the rheological point of view and its properties were compared with other commercially used galactomannans. Our results showed that D. mollis galactomannan is appropriate to several applications in food industries. As a whole, our results indicate that both, native seeds and seeds of eucalyptus, might be used in several industrial applications so that these might be used as part of programs of sustainable use of biodiversity, leading to social and technological benefits to society. / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

[ES] Esta tesis aborda la caracterización y posible utilización de la goma de alholva (Trigonella foenum-graecum) (FSG, por sus siglas en inglés) en la nutrición de gazapos durante el período posterior al destete como una alternativa al uso de antimicrobianos, centrándose en el comportamiento de la goma extraída con diferentes niveles de fibra dietaria, tanto in vitro como in vivo. En el primer experimento, a partir de una dieta basal comercial de conejo, se formularon tres dietas experimentales con niveles graduales de inclusión de FSG (0, 0.25, 0.50%) administrados a tres grupos de conejos desde el destete a los 31 días hasta el sacrificio a los 94 días. Se estudió el efecto de las dietas experimentales sobre la digestibilidad fecal en dos edades (38-41 días y 56-59 días), además de los parámetros de fermentación cecal al final del experimento. Por otro lado, a partir de la misma dieta comercial de conejo, se formularon cinco dietas experimentales que contenían 0. 0.125, 0.25, 0.50 y 100% de FSG, que se sometieron a incubación in vitro con inóculo cecal de conejo durante 72 h. Se midieron la producción de gas y las variables de fermentación. La digestibilidad fecal aparente y los parámetros de fermentación cecal no se vieron afectados significativamente por la inclusión in vivo de FSG hasta 0.5%. Sin embargo, los animales alimentados con FSG mostraron valores de pH cecal más bajos. La inclusión gradual en la dieta de FSG aumentó la concentración in vitro de ácidos grasos volátiles (VFA, por sus siglas en inglés), mientras que el FSG puro aumentó la producción asintótica de gas y la tasa máxima de degradación del sustrato y disminuyó el tiempo de incubación en el que se forma la mitad de la cantidad asintótica de gas. La incubación in vitro de FSG puro disminuyó el valor del pH, la concentración de ácido láctico y la concentración de N-NH3, y aumentó la de VFA. En el segundo experimento, el FSG se caracterizó para determinar su composición química, su contenido de galactosa y manosa y su potencial como prebiótico. Se evaluaron tanto FSG puro como niveles graduales (0, 5, 10, 15 y 20 g/kg) incluidos en dietas ricas en fibra soluble (SF, por sus siglas en inglés) de pulpa de remolacha (incluida al 10%) y dietas ricas en fibra insoluble (IF, por sus siglas en ingles) de semilla de uva desengrasada (incluida al 10%). Se sometieron a digestión enzimática con pepsina y pancreatina y luego sus fracciones indigestibles se sometieron a fermentación usando inóculo cecal. Se midieron las fracciones no digestibles después de la digestión enzimática, así como las fracciones no fermentables y las variables de fermentación después del tiempo de incubación (48 h). La FSG se compone principalmente de galactosa y manosa (630 g/kg) en una proporción de 1: 1 y un nivel moderado de proteínas (223 g/kg). El FSG puro se vio poco afectado por la digestión enzimática, ya que solo se disolvieron 145 g/kg. Sin embargo, desapareció casi por completo (984 g/kg) durante el proceso de fermentación. En consecuencia, FSG aumentó la concentración de VFA, disminuyó el valor de pH y la concentración de N-NH3. La inclusión gradual de FSG en las dietas de conejos afectó la digestión de algunos nutrientes, como las fracciones fibrosas, el almidón y las proteínas, además de aumentar la fracción fermentada en la dieta SF, pero sin ningún efecto relevante en el perfil de fermentación. En el tercer experimento, se formularon cuatro dietas de acuerdo con un diseño factorial 2 x 2: una dieta convencional de conejo (C), la misma dieta C suplementada con 10 g / kg de FSG, una dieta de bajo riesgo (LR, por sus siglas en inglés) y la misma dieta LR suplementada con 10 g/kg de FSG. Las dietas C y LR se diferenciaban en el nivel de SF y proteína bruta (CP, por sus siglas en inglés) (104 vs 205 y 156 vs 121 g/kg de SF y CP respectivamente para dietas C y LR). Doscientos dieciséis conejos de la línea LP se alojaron en jaulas individuales, se dividieron aleatoriamente entre los cuatro tratamientos y se les permitió el libre acceso al alimento y al agua. La mortalidad, la morbilidad, el índice de riesgo sanitario (HRi, por sus siglas en inglés), la ingestión diaria de pienso (DFI, por sus siglas en inglés), la ganancia media diaria (ADG, por sus siglas en inglés) y el índice de conversión alimenticia (FCR, por sus siglas en inglés) se controlaron hasta los 63 días de edad. El coeficiente de digestibilidad aparente total del tracto digestivo (CTTAD, por sus siglas en inglés) de los nutrientes se determinó en doce conejos por tratamiento, entre los 49 y 53 días de edad y finalmente se midió el ambiente cecal a los 63 días de edad. La inclusión de FSG en la dieta a 10 g/kg de alimento no afectó al rendimiento durante el cebo ni al CTTAD de los nutrientes, pero aumentó ligeramente la digestibilidad de la fibra neutrodetergente (NDF, por sus siglas en inglés) y la fibra ácido-detergente (ADF, por sus siglas en inglés) en las dietas C. Del mismo modo, los parámetros cecales no se vieron afectados por la inclusión de FSG, excepto la concentración de ácido caproico en las dietas C. Sin embargo, las dietas LR disminuyeron la mortalidad, HRi, DFI, ADG y CTTAD de materia orgánica y CP pero aumentaron FCR y CTTAD de NDF y ADF con respecto a las dietas C. Además, las dietas LR aumentaron la concentración de VFA, la proporción de ácido acético, isobutírico e isovalérico mientras que disminuyeron la materia seca del contenido cecal, NNH3 y la proporción de ácidos butírico, caproico y valérico. En resumen, la FSG responde perfectamente a las dos primeras condiciones para ser un prebiótico, ya que no es digestible por las enzimas gastrointestinales antes del ciego y es altamente fermentado una vez que alcanza el ciego. Parece afectar selectivamente a la microbiota cecal debido a su efecto sobre la concentración de VFA y N-NH3, además de su efecto sobre la proporción de caproico y valérico en dietas convencionales. FSG podría aumentar la viscosidad de la digesta limitando la solubilización de algunos nutrientes como el almidón y la proteína. FSG parece ser más efectivo en dietas comerciales convencionales que en dietas de bajo riesgo. Finalmente, se confirmó que las dietas con alto nivel de SF y bajo de CP podrían ser una buena herramienta contra la enteropatía epizoótica del conejo (ERE, por sus siglas en inglés) en un sistema de producción no medicado, a costa de peores parámetros de crecimiento. / [EN] This thesis tackles the possible characterisation and utilisation of fenugreek (Trigonella foenum-graecum) seed gum (FSG) in the nutrition of young rabbits during the post-weaning period as an alternative to antimicrobials uses. The study was focussed on the behaviour of the extracted gum with different dietary fibre levels, both in vitro and in vivo. In a first trial, starting from a basal commercial rabbit diet, three experimental diets were formulated with gradual levels of inclusion of FSG (0, 0.25, 0.50 %) given to three groups of rabbits starting from weaning at 31 days old to slaughter 94 days old. The effect of the experimental diets was studied on the faecal digestibility of the diet in two ages (38-41 days and 56-59days) and on the caecal fermentation parameters at the end of the experiment. On the other hand, starting from the same commercial rabbit diet five experimental diets were formulated containing 0, 0.125, 0.25, 0.50 and 100% of FSG that were submitted to in vitro incubation with rabbit caecal inoculum during 72h. Gas production and fermentation traits were measured. Apparent faecal digestibility and caecal fermentation parameters were not significantly affected by the in vivo inclusion of FSG up to 0.5%. However, animals fed with FSG showed lower caecal pH values. Gradual dietary inclusion of FSG increased in vitro concentration of volatile fatty acids (VFA), while pure FSG increased the asymptotic gas production and the maximum substrate degradation rate and decreased the time after incubation at which half of the asymptotic amount of gas is formed. In vitro incubation of pure FSG decreased pH value, lactic acid concentration and N-NH3 concentration and increased that of VFA. In a second trial, FSG was characterised determining its chemical composition, galactose and mannose content and prebiotic potential. Pure FSG and gradual levels of FSG (0, 5, 10, 15 and 20 g/kg), included both in diets rich in soluble fibre (SF) from beet pulp (included at 10%) or in diets rich in insoluble fibre (IF) from defatted grape seeds (included at 10 %), were evaluated. They were submitted to enzymatic digestion with pepsin and pancreatin and then their indigestible fractions were submitted to fermentation using caecal inoculum. The indigestible fractions after enzymatic digestion were measured, as well as the nonfermentable fractions and the fermentation traits after incubation time (48 h). FSG was mostly composed of galactose and mannose (630 g/kg) in 1:1 ratio and a moderate protein level (223 g/kg). Pure FSG was weakly affected by enzymatic digestion, only 145 g/kg was dissolved. However, it was almost entirely disappeared (984 g/kg) during the fermentation process. Consequently, FSG increased VFA concentration and decreased both pH value and N-NH3 concentration. Th gradual inclusion of FSG in rabbit’s diets affected some nutrients digestion such as the fibre fractions, starch and protein, besides to increase the fermentation fraction in SF diet but without any relevant effect on the fermentation profile. In a last third trial, four diets were formulated according to 2 x 2 factorial design: a conventional rabbit diet (C), the same C diet supplemented by 10 g/kg of FSG, a low-risk diet (LR), and the same LR diet supplemented by 10 g/kg of FSG. C and LR diets differed in SF and crude protein levels (CP) (104 vs 205 and 156 vs 121 g/kg of SF and CP respectively for C and LR diets). Two hundred and sixteen weaned rabbits (28 days of age) of the LP line were allocated in individual cages and divided randomly between the four treatments and allowed free access to feed and water. Mortality, morbidity, health risk index (HRi), daily feed intake (DFI), average daily gain (ADG) and feed conversion ratio (FCR) were controlled until 63 days of age. Coefficient of total tract apparent digestibility (CTTAD) of nutrients, on twelve rabbits per treatment, was determined from 49 to 53 days of age and finally, caecal environment was measured at 63 days of age. FSG dietary inclusion at 10 g/kg did not affect performance or CTTAD of nutrients but did slightly increased neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) digestibility in C diets. Similarly, caecal parameters were not affected by FSG except caproic acid concentration in C diets. Nevertheless, LR diets decreased mortality, HRi, DFI, ADG and CTTAD of organic matter and CP but increased FCR and CTTAD of NDF and ADF respect to C diets. Moreover, LR diets increased VFA concentration, the proportion of acetic, isobutyric and isovaleric while decreased the dry matter of the caecal content, N-NH3 and the proportion of butyric, caproic and valeric acids. To summarise, FSG perfectly responds to the two first conditions to be prebiotic, being not digestible by gastrointestinal enzymes before the caecum and highly fermented once reached the caecum. It seems to affect selectively caecal microbiota due to its effect on VFA and N-NH3 concentration besides to its effect on caproic and valeric proportions in conventional diets. FSG could increase viscosity of digesta limiting the solubilisation of some nutrients such starch and protein. FSG seems to be more effective in conventional commercial diets than in low-risk diets. Finally, it was confirmed that diets with high SF level and low CP could be a good tool against epizootic rabbit enteropathy (ERE) in a nomedicated breeding system at the cost of impaired growth parameters. / [CA] Aquesta tesi aborda la caracterització i possible utilització de la goma de fenigrec (Trigonella foenum-graecum) (FSG, per les sigles en anglès) en la nutrició del conills durant el període posterior al deslletament com una alternativa a l'ús d'antimicrobians, centrant-se en el comportament de la goma extreta amb diferents nivells de fibra dietària, tant in vitro com in vivo. En el primer experiment, a partir d'una dieta basal comercial de conill, es van formular tres dietes experimentals amb nivells graduals d'inclusió de FSG (0, 0.25, 0.50%) administrats a tres grups de conills des del deslletament als 31 dies fins al sacrifici als 94 dies. Es va estudiar l'efecte de les dietes experimentals sobre la digestibilitat fecal en dues edats (38-41 dies i 56-59 dies), a més dels paràmetres de fermentació cecal a la fi de l'experiment. D'altra banda, a partir de la mateixa dieta comercial de conill, es van formular cinq dietes experimentals que contenien 0. 0.125, 0.25, 0,50 i 100% de FSG, que es van sotmetre a incubació in vitro amb inòcul cecal de conill durant 72 h. Es van mesurar la producció de gas i les variables de fermentació. La digestibilitat fecal aparent i els paràmetres de fermentació cecal no es van veure afectats significativament per la inclusió in vivo de FSG fins a 0.5%. No obstant això, els animals alimentats amb FSG van mostrar valors de pH cecal més baixos. La inclusió gradual en la dieta de FSG va augmentar la concentració in vitro d'àcids grassos volàtils (VFA, per les sigles en anglès), mentre que el FSG pur va augmentar la producció asimptòtica de gas i la taxa màxima de degradació del substrat i va disminuir el temps d'incubació en el qual es forma la meitat de la quantitat asimptòtica de gas. La incubació in vitro d'FSG pur va disminuir el valor del pH, la concentració d'àcid làctic i la concentració de N-NH3, i va augmentar la de VFA. En el segon experiment, el FSG es va caracteritzar per determinar la seva composició química, el seu contingut de galactosa i manosa i el seu potencial com prebiòtic. Es van avaluar tant FSG pur com nivells graduals (0, 5, 10, 15 i 20 g/kg) inclosos en dietes riques en fibra soluble (SF, per les sigles en anglès) de polpa de remolatxa (inclosa al 10%) i dietes riques en fibra insoluble (IF, per les sigles en anglès) de llavor de raïm desgreixada (inclosa al 10%). Es van sotmetre a digestió enzimàtica amb pepsina i pancreatina i després les fraccions indigeribles es van sotmetre a fermentació usant inòcul cecal. Es van mesurar les fraccions no digestibles després de la digestió enzimàtica, així com les fraccions no fermentables i les variables de fermentació després del temps d'incubació (48 h). La FSG es compon principalment de galactosa i manosa (630 g/kg) en una proporció de 1: 1 i un nivell moderat de proteïnes (223 g/kg). El FSG pur es va veure poc afectat per la digestió enzimàtica, ja que només es van dissoldre 145 g/kg. No obstant això, va desaparèixer gairebé del tot (984 g/kg) durant el procés de fermentació. En conseqüència, FSG va augmentar la concentració de VFA, va disminuir el valor de pH i la concentració de N-NH3. La inclusió gradual de FSG en les dietes de conills va afectar la digestió d'alguns nutrients, com les fraccions fibroses, el midó i les proteïnes, a més d'augmentar la fracció fermentada en la dieta SF, però sense cap efecte rellevant en el perfil de fermentació. En el tercer experiment, es van formular quatre dietes d'acord amb un disseny factorial 2 x 2: una dieta convencional de conill (C), la mateixa dieta C suplementada amb 10 g/kg de FSG, una dieta de baix risc (LR, per les sigles en anglès) i la mateixa dieta LR suplementada amb 10 g/kg de FSG. Les dietes C i LR es diferenciaven en el nivell de SF i proteïna bruta (CP, per les sigles en anglès) (104 vs 205 i 156 vs 121 g/kg de SF i CP respectivament per a dietes C i LR). Doscents setze conills de la línia LP es van allotjar en gàbies individuals, es van dividir aleatòriament entre els quatre tractaments i se'ls va permetre el lliure accés a l'aliment i a l'aigua. La mortalitat, la morbiditat, l'índex de risc sanitari (HRi, per les sigles en anglès), la ingestió diària de pinso (DFI, per les sigles en anglès), el guany mitjá diari (ADG, per les sigles en anglès) i l'índex de conversió alimentària (FCR, per les sigles en anglès) es van controlar fins als 63 dies d'edat. El coeficient de digestibilitat aparent total del tracte digestiu (CTTAD, per les sigles en anglès) dels nutrients es va determinar en dotze conills per tractament, entre els 49 i 53 dies d'edat i finalment es va mesurar l'ambient cecal als 63 dies d'edat. La inclusió de FSG en la dieta a 10 g/kg d'aliment no va afectar el rendiment durant l'engreix ni el CTTAD dels nutrients, però va augmentar lleugerament la digestibilitat de la fibra neutre-detergent (NDF, per les sigles en anglès) i la fibra àcid-detergent (ADF, per les sigles en anglès) en les dietes C. De la mateixa manera, els paràmetres cecals no es van veure afectats per la inclusió de FSG, excepte la concentració d'àcid caproic en les dietes C. No obstant això, les dietes LR van disminuir la mortalitat, HRi, DFI, ADG i CTTAD de matèria orgànica i CP però van augmentar FCR i CTTAD de NDF i ADF pel que fa a les dietes C. A més, les dietes LR van augmentar la concentració de VFA, la proporció d'àcid acètic, isobutíric i isovalèric mentre que van disminuir la matèria seca del contingut cecal, N-NH3 i la proporció d'àcids butíric, caproic i valéric. En resum, la FSG respon perfectament a les dues primeres condicions per ser un prebiòtic, ja que no és digestible pels enzims gastrointestinals abans del cec i és altament fermentat un cop que arriba al cec. Sembla afectar selectivament a la microbiota cecal pel seu efecte sobre la concentració de VFA i N-NH3, a més del seu efecte sobre la proporció de caproic i valéric en dietes convencionals. FSG podria augmentar la viscositat de la digesta limitant la solubilització d'alguns nutrients com el midó i la proteïna. FSG sembla ser més efectiu en dietes comercials convencionals que en dietes de baix risc. Finalment, es va confirmar que les dietes amb alt nivell de SF i baix de CP podrien ser una bona eina contra la enteropatia epizoòtica del conill (ERE, per les sigles en anglès) en un sistema de producció no medicat, a costa d'pitjors paràmetres de creixement. / Jihed, Z. (2020). In vitro and in vivo characterization of galactomannanes extracted from fenugreek seeds (Trigonella foenum-graecum) for young rabbit nutrition [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153714 / TESIS

Astragalus gombo Bunge (Fabaceae) est une plante bien représentée dans le Sahara Septentrional Est Algérien (région de Ouargla, Algérie) et couramment utilisée comme fourrage pour les animaux ou en médecine traditionnelle. Malgré de nombreuses publications sur la richesse en polysaccharides d’autres espèces appartenant au genre Astragalus et la description de leurs propriétés biologiques putatives ou avérées, aucune étude ne s’est intéressée à l’espèce gombo. L’objectif de ce travail de thèse a donc été de réaliser des investigations sur plusieurs parties de cette plante en vue d’extraire, identifier et caractériser son contenu en polysaccharides. Dans un second temps les propriétés biologiques et rhéologiques de ces polymères ont été étudiées afin d’identifier d’éventuelles voies de valorisation. Les résultats obtenus ont permis de détecter la présence de composés pectiques et hémicellulosiques dans la tige d’Astragalus gombo et celle d’un galactomannane dans les graines. Le galactomannane est de haute masse moléculaire (1,1x106 Da) et est constitué d’une chaine principale de β-(1→4)-D-mannane ramifiée en α-(1→6) par des résidus Dgalactopyranoses avec un rapport M/G de 1,7. La caractérisation de ses propriétés rhéologiques a révélé un comportement typique rhéofluidifiant et des propriétés viscoélastiques. L’étude des activités biologiques associées à ce biopolymère a révélé son potentiel comme prébiotique et antioxydant. / Astragalus gombo Bunge (Fabaceae) is a terrestrial plant occuring in the East Septentrional Sahara (Ouargla, Algeria). It is commonly used as fodder or in traditional medicine by local populations. Despite numerous publications focusing on polysaccharidic contents of Astragalus species and the designation of their putative or proved biological activities, no study has examined those of A. gombo. The objective of this thesis was firstly to investigate several organs of this plant for their polysaccharide contents. In a second step, the biological and rheological properties of these biopolymers have been studied to identify ways of adding value. Results led to the identification of pectic compounds and hemicelluloses in the rods of Astragalus gombo whereas a galactomannan was detected in its seeds. This galactomannan was a high molecular weight macromolecule composed of a β-(1→4)-D-mannan skeleton ramified by residues of D-galactopyranoses. The M/G ratio was of 1.7. The characterization of its rheological behavior was typic of that of a rheofluidifiant fluid with viscoelastic properties. The study of its biological properties showed its potential as prebiotic and antioxidant agent.