CARBOHYDRATE

Author: GALED CERESUELA GEMMA.
Year: 2004.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE CC. QUÍMICAS.
Place of preparation: INSTITUTO DE ESTUDIOS BIOFUNCIONALES DE LA UCM.

Summary: The need to find new materials for the purposes of the industry, the growing interest in manufacturing porductos manufactured in a manner consistent with the conservation of the environment and the high cost of some synthetic materials have resulted in a growing interest in the field of polymers natural. The chitin is an abundant polysaccharide in nature serving as material support exoskeletons of crustaceans, insects and arthropods as well as in the cell walls of plants (lower green algae and fungi). It consists of monomers 2-acetoamido-2deoxi- BD-glucopiranosa (N-acetilglucosamina) and 2-amino-2deoxi-BD-glucopiranosa (N-glucosamina). quitosano is derived desacetilado of laquitina and nature only found in the fungal mycelium belonging to the family Mucoraceae as Absidia, Mucor and Rhizopus.En the laboratory and in the industry is derived primarily from curstáceos due to the large amount of cáscadas available as a by-product of the food industry and fisheries. The quitosano has multiple applications, is used in the food industry, agricultural, cosmetics, pharmaceuticals (which are used as a biodegradable material in drug delivery system) and in the sectors biomédio (as hipolipidémico and hipocolesterolémico) and biotechnology (for immobilization of Enzymes). however, not all quitosanos are equal and not all are valid for all applications. In this thesis work has been carried out adjustment of the experimental conditions to obtain the optimum product for each apllicación.Se has worked with 6 species curstáceos from different parts of the world (P.granulosa, L.antarcticus, P.muelleri, C.sapidus and P.vannamei). Beginning of them have been isolated chitin and has obtained its derivative quitosano.Los chemical processes involved in obtaining both polymers will be influenced by a number of parameters, such as concentration alkali and acid, the temperature of porceso, reaction time, the atmosphere in which takes place primarily their place of origin. Subsequently were obtained by despolimerización chemical and enzymatic heterooligómeros of quitosanos producidos.La greater or lesser suitability of the products for each application, which has been dependent on the physicochemical characteristics of the polymer obtained (degree of desacetilación, intrinsic viscosity and molecular weight), which in turn comes from the place of growth of crustacean and the experimental conditions employed in each process.

Author: ALONSO CASAJÚS NORA.
Year: 2004.
University: NAVARRA [www.unav.es].
Place of defense: INSTITUTO DE AGROBIOTECNOLOGÍA.
Place of preparation: UNIVERSIDAD PÚBLICA DE NAVARRA.

Summary: The starch and glycogen are the main forms of energy reserves in plants and bacteria respectivamente.Además, amidón is essential raw material in multiple sectors of modern industry. This dissertation work has been divided into two partes.La first is related to bacterial glycogen degradation and biological function of this poliglucano.La information on the possible involvement of glycogen demonstrate that the glycogen acts ocmo a "carbon capacitor" that contributes to preserve osmotic homeostasis of the bacteria.La possible involvement of glycogen fosfirilasa (GlgP) in the degradation of glycogen now has been based on indirect evidence of biochemical kind, and never have been built and characterized bacteria with altered levels of GlgP. In this thesis work, production and characterization of bacteria with altered levels of GlgP has allowed me to show that 1) this enzyme plays a key role in the degradation of glycogen in the production of precursors for síntesisw of maltodextrins, 2) the control that GlgP exercises on the degradation glucógneo and biosynthesis maltodextrins, 2) control between different strains of E.coli and 3) GlgP acted during the process of accumulation of glycogen. The second part of the work is related to the biosynthesis of photosynthetic tissues in plantas.Según the classical model of biosynthesis of starch in photosynthetic tissues in plantas.Según the classical model of starch biosynthesis of the sacaroda, and starch are the products of two routes unidirectional taking place in the cytosol and the chloroplast respectivamente.Además, this model assumes that the ADP-glucose pirofosforilasa (AGP) is the only enzyme responsble for the biosynthesis of the parent molecule of starch, ADPglucosa (ADPG). however, over the past few years have appeared copious evidence to suggest the involvement of the sucrose synthase (SuSy) in the production of ADPG citosólido necessary for the synthesis of almidón.Para analyze which of the two models is correct, I have determined the subcellular localization of ADPG linked to the biosynthesis of alidón used as the cloroplasto.Los results made it possible to conclude that, contrary to what is suggested by the classical model, most ADPG accumulates in the citosol.La cytosolic localization of ADPG suggests that the enzyme responsible for the biosynthesis of ADPG is not the PGA plastidial but SuSy.Por therefore porcedí to construct and characterize plants superexpresan SuSy.Los results indicate that 1) the ADPG produced by SuSy is linked to the biosynthesis of starch, 2 ) SuSy exerts an important control on the process of biosynthesis of starch and 3) SuSy and not AGP catalyzes the production of ADPG that accumulates in the leaves.