MICROBIAL PROCESSES

Author: ALVAREZ RODRIGUEZ M. LUISA.
Year: 2002.
University: EXTREMADURA [www.unex.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS - UNIVERSIDAD DE EXTREMADURA.

Summary: The cork cork taint or pollution is a serious problem affecting wines from around the world. It consists of the presence in the cork stopper metabolites of microbial origin, which came to pass to him flavorings and / or unpleasant flavors ruin their organoleptic properties of nature. Among the compounds responsible for cork taint highlights cloroanisoles and especially 2,4,6-tricloroanisol (2,4,6-TCA). In this work have been isolated from cork a total of 14 filamentous fungi, of which 11 are capable of producing 2,4,6-TCA when they grow directly on cork. The 2,4,6-TCA is formed in the fungus Trichoderma longibrachiatum by O methylation of pesticide clorofenólico 2,4,6-TCP, this reaction is catalyzed by a chlorophenol O-metiltransferasa CPOMT. This is an inducible enzyme specifically chlorophenol that can biometilar a wide range of halogenated phenols. This enzyme has been characterized in detail. The results have enabled us to design a possible solution biotechnology to combat the emergence of 2,4,6-TCA in cork stopper.

Author: SERRANO MORENO CONCEPCIÒâN.
Year: 2003.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE MEDICINA (UCM).
Place of preparation: FACULTAD DE MEDICINA DE LA UCM.

Summary: The possible contaminaciÃÂ ³ n microbial of water that are used in human communities poses a threat to the health PÃÂ fourth blica.Las Waters Mineromedicinales, both those that are ingested, such as those used to balneaciÃÂ ³ n, are subject by law to own criteria for monitoring its quality, and given that, in order to declare utility pÃÂ sixth Republic must emerge free gÃÂ © rmenes, and other contaminaciÃÂ ³ n, estÃÂ now a free treatments quÃÂmicos. The overall objective of this work is to experimentally evaluate the behavior Natural gÃÂ © rmenes potential contaminants from baÃÂ ± istas, water delos spas, in its forms and ATCC Isolated ClÃÂnico such as: E.aureus (coag. + ), E. Coli, P. Aeruginosa and L. Pneumophila and also assess the quality microbiolÃÂ ³ gica of spring waters and facilities crenoterÃÂ ¡spades of Spa Alenge, to the corresponding results could confirm the relevance of the citad exenciÃÂ ³ No official and adapt if necessary protocol hygiene for such a center termal.Siguiendo the sistemÃÂ ¡tica of anÃÂ ¡lisis microbiolÃÂ ³ gico and hidrologÃÂa mÃÂ © dica, and considering the meanings estadÃÂsticas the results were CONCLUDES: Waters Mineromedicinales do not facilitate the growth of gÃÂ © rmenes above, that within the gÃÂ © rmenes modify their enzymes, that the waters of Spa Alange for his condiciÃÂ ³ n oligomineral-radiactiva presented very good quality microbiolÃÂ ³ gica and that the waters of the central and asÃÂ as demÃÂ ¡s aquÃÂ studied may remain exempt treatments quÃÂmicos.

Author: LATATU NUÑEZ AINHOA.
Year: 2004.
University: PAÍS VASCO [www.ehu.es].
Place of defense: FACULTAD DE CIENCIA Y TECNOLOGIA.
Place of preparation: FACULTAD DE CIENCIA Y TECNOLOGIA.

Summary: ACUATICOS SYSTEMS IN THE DEPREDACION SELECTIVE TO THE EXERCISE PROTOZOA BACTERÍVOROS, ALONG WITH LARGE CAPACITY OF ADAPTATION OF PICOPLANCTON AND HIGH RATE OF GROWTH POTENTIAL, LEADING TO A QUICK SUCCESSION OF THE COMMUNITY PROCARIOTICA TOWARDS A COMMUNITY POTENTIALLY RESISTANT TO DEPREDACION. IN THIS WORK HAS BEEN ANALIZADO THE IMPORTANCE OF VARIOUS FACTORS ON THE DEVELOPMENT OF DIFFERENT MECHANISMS OF RESISTANCE FROM DEPREDACION, AS WELL AS ON THE IMPORTANCE OF EACH OF THESE ARRANGEMENTS. AS THE RESULTS OBTAINED MAY ECONTRAR A PROPORCION VARIABLE PROCARIOTAS POTENTIALLY RESISTENTES TO DEPREDACION IN VARIOUS ACUATICOS ECOSYSTEMS. THE COMPOSITION OF THE NUTRITION RESOURCES AVAILABLE, AS WELL AS THE TYPE OF DEPREDADOR PREDOMINANTE ARE TWO FACTORS INFLUENCING DIRECTLY IN THE STRUCTURE OF THE COMMUNITY PICOPLANCTONICA WITH THE DEVELOPMENT OF RESISTANCES TO DEPREDACION. BY LATEST GETS MANIFESTO FOR THE IMPORTANCE OF THE SIGNS OF CHEMICAL MECHANISM AS STRENGTH OF THE PROCARIOTAS IN PRIOR TO THE STAGE PROCESS OF DEPREDACION. IN REGARD TO THE COMPOSITION OF MAJOR GROUPS TAXONOMICOS THE COMMUNITY PROCARIOTICA NOT FIND AN CLARA RELATIONSHIP BETWEEN THE STRUCTURE TAXONOMICA AND DEVELOPMENT OF RESISTANCES TO DEPREDACION. FEATURES ECOLOGICAS ACUATICO SYSTEM AVAILABILITY OF NUTRIENTS AND CONCRETE FACTORS ARE MORE DIRECTLY RELATED TO THE COMPOSITION TAXONOMICA.

Author: TOLEDO ARANA ALEJANDRO.
Year: 2004.
University: PÚBLICA DE NAVARRA [www.unavarra.es].
Place of defense: INSTITUTO DE AGROBIOTECNOLOGÍA Y RECURSOS NATURALES.
Place of preparation: INST.DE AGROBIOTECNOLOGÍA Y RECURSOS NATURALES..

Summary: The biofilms are communities of microorganisms in a matrix that binds each other and live or inert substrates. Although they are widely distributed in nature and in many cases have beneficial effects, their study has been boosted after discovery of its relationship with chronic infections associated both medical implants and tissue (middle ear infections, prostate, pneumonia in patients with cystic fibrosis, osteomyelitis, etc.). In the interior of the biofilm, bacteria have an increased resistance to antibiotics, the opsonización by antibodies and phagocytosis, which explains the chronic nature of these infections. Although in recent years there has been an explosion in the number of articles describing new features of the biology of biofilms, the genetic mechanisms involved in the process of formation of biofilms are virtually unknown. With the conviction that only through a precise knowledge of the process we will be able to identify likely targets for the development of drugs to help us fight infections associated with biofilms, this Doctoral Thesis has focused on the characterization of the process of formation of biofilm of Staphy / ococcus aureus, one of the species most often associated with bacterial infections of medical implants. The starting point was the Bap protein (Biofilm associated protein), identified in a previous work by our research group through mutagenesis by transposition of the strain S. Aureus V329. Bap presents a structural organization similar to other surface proteins of unknown function in different species of bacteria such as: Esp E. Faecalis, mus20 of Pseudomonas putida, and sty2875 Sa / monel / a typhi. Taking into account the structural homology between Bap and Spa, we decided to examine whether there was a link between the presence of the esp gene and the ability to produce biofilm by E. Faecalis. The results showed that the ability of biofilm formation was widespread among clinical isolates of E. Faecalis and that the presence of the esp gene was involved in the formation processes of these biofilms. Continuing with the functional analysis of Bap, studies in sílico revealed the presence of calcium binding domains, which led us to investigate the effect of calcium on the role of Bap. The results showed that quantities milimolares calcium added to the culture medium inhibited the formation of biofilm strains Bap-positivas. The directed mutagenesis on two of the calcium binding domains, resulting in a mutant that retained the ability to form biofilm but now was not inhibited by the addition of calcium, indicating that the ion binds them to exercise their action. The fact that strains Bappositivas have only been isolated from animals with bovine mastitis and that the concentration of calcium which the biofilm is inhibited is similar to that found in the serum of milk, suggests specific mechanisms regulating biofilm never described to date. The results so far did intuit the existence of various mechanisms for forming biofilm depending on the origin of the strains, so we decided to make a new mutagenesis by transposition, this time using the strain of S. Aureus 15981, a clinical isolate from a human otitis media. For the identification of the genes involved in biofilm formation in this aisl'ado followed two different strategies. The first, following the usual methods, involved identifying mutants that had lost the ability to form biofilm in TSBg and / or B2, which is not 8 s permit cb2 would identify genes essential and positive regulators of the process. The results showed that a number of mutants had affected the ability of biofilm formation, which we can highlight the overall regulatory Sara, the operon icaADBC responsible for the synthesis of the main polysaccharide biofilm and SAl117. The study of regulatory SarA took place in the Doctoral Thesis of Jaione Valle-Turrillas. In this part of the job, we focused on the characterization of gene SA1117. The protein SA1117 presents a high similarity with polynucleotide fosforilasas of Bacil / us subti / is and Escherichia coli. Studies enzymatic activity of cellular extracts showed that the mutant SA1117 lacked activity 3-5 exorribonucleasa characteristic of polinucleotido fosforilasas and hence the gene was renamed as pnpA. The mutant in pnpA presented a marked decrease in the accumulation of PNAG, however transcription operon icaADBC was only slightly diminished. The reasons for the decrease in the accumulation of PNAG are still not clear. Also GeneChip Microarrays have been used to try and understand what the signaling cascade that relates to pnpA with the regulation of biofilm formation process. The second strategy arose during the development of an environment chemically defined to study how environmental signals affect the process of formation of biofilm. Unexpectedly, most of the clinical isolates of S. Aureus were unable to form biofilm in the synthetic one, we suggested that the process might be repressed in that medium. To identify these repressors, we conducted mutagenesis but this time selecting mutants biofilm positive in the middle synthetic strategy that had not been used previously. Thus we identified that the system of two components ArlSR is a negative regulator of biofilm formation of S. Aureus. Comprehensive studies of this mutant revealed that in the absence of arlRS it forms a biofilm independent exopolisacárido PIA / PNAG. This thesis has highlighted the complexities involved in the formation of bacterial biofilm, showing that multiple factors may be involved and may also be strictly regulated at various levels. Moreover, despite the exopolisacáridos are a major component in a lot of cases and parcel of the biofilm matrix, our results suggest that certain proteins also play an important role in this process.

Author: VIDAL MAS JAUME.
Year: 2005.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE FARMACIA.

Summary: The lipoxigenses are a family of enzymes that are found in mammals and plants on a regular basis in various tissues. We also have begun to describe in lower organisms and lately in some microorganisms. The lipoxigenasa of Pseudomonas aeruginosa is the first lipoxigenasa described in prokaryotes. These are enzymes which convert the fatty acids in hydroxylated derivatives. The use of enzymes is increasingly widespread industrial level, with the aim of transforming substrates or to obtain products with high specificity. This és the goal of this dissertation, clone and express the lipoxigenasa Pseudomonas aeruginasa in E. Coli, in quantities sufficient to obtain such hydroxylated derivatives of fatty acids through the transformation by the lipoxigenasa. This study is framed within the project CTQ-0771-CO2-01/PPQ. We have generated and purified different forms of the protein through recombinant-DNA technology. One of these recombinant proteins has been characterized by determining the spectrum of substrates (being active to arachidonic acid, linoleic, linolenico i oleic), we reaction conditions such as pH optimum ara (dependent variable substrate in tre 6 i 8), optimal reaction temperature (25C) i thermal stability (active until the 50C). Have been determined by the inhibition product substrate existing i les kinetic constants (KM, Vmax, Kcat, catalytic efficiency i) together with the influence of ethanol on the enzyme activity. També studies have been carried out to conduct a pre-scaling of the production process of derivatives monohidroxilados determining the main parameters of the biotransformation, such as reaction time, concentration of substrate i influence of aeration in the transformation of the fatty acids .

Author: PÉREZ LORENZO MARÍA.
Year: 2005.
University: VIGO [www.uvigo.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTADE DE CIENCIAS DE OURENSE, CAMPUS DE OURENSE, UNIVERSIDADE DE VIGO.

Summary: The purpose of this study was to determine the in vivo effect of probiotic bacteria marine Roseobacter 27-4 in improving the survival of larvae turbot infected with the pathogen Vibrio (Listonella) anguillarum, at the pilot plant and the usual conditions of larval cultivation. The study was conducted in 3 phases: 1-Establishment of an experimental model (reproducible) infection larvae turbot with the pathogen. 2, - Confirmation of the safety Roseobacter 27-4 for the agencies cultivation (microalgae, rotifers and Artemia) and incorporation of probiotic in the larval cropping system. 3-Validating probiotic effect of Roseobacter 27-4 in larvae infected with V.anguillarum and establishment of a model application. Adding Roseobacter 27-4 (via rotífero) larvae infected with the pathogen (via rotífero) reduced mortality larval demonstrating a clear probiotic effect in vivo. The presence of Roseobacter 27-4 in the larvae could be detected at the level of intestinal lumen, but without colonization of the gut epithelium.