The objectives of this study were to investigate the long-term effects of feeding increasing supplemental levels (20, 120, or 220 mg/kg) of dietary copper (Cu) as tribasic copper chloride (TBCC) or copper sulfate (CuSO4) on performance, antioxidant status, nutrient digestibility, and trace mineral deposition of sows and piglets; as well as to assess nursery dietary Cu levels on growth performance and response to immunological challenge in nursery pigs from sows fed either high or low Cu diets. In the long-term sow experiment, sows fed TBCC diets had greater adjusted weaning weight for litter and piglet (P < 0.10), as well as adjusted litter and piglet weight gain (P < 0.10) when compared to sows that received CuSO4 diets. Increasing dietary Cu level linearly increased live born piglet weight (P = 0.06). Sows fed TBCC diets had lower apparent total tract digestibility (ATTD) of ether extract (P = 0.01) during late gestation, but greater ATTD of dry matter, nitrogen, and phosphorous during lactation (P < 0.05). Increasing Cu levels linearly increased dry matter digestibility in lactating sows (P = 0.02). Milk from sows fed TBCC diets had a greater concentration of protein (P = 0.02) than that from sows fed CuSO4 diets. Increasing Cu levels increased levels of milk fat and Cu (linear, P < 0.05); but linearly decreased lactose and Zn levels (P < 0.05). Lactating sows fed TBCC diets had a greater activity of Cu/Zn superoxide dismutase (SOD) and ceruloplasmin in serum than those fed CuSO4 diets (P < 0.05). Increasing dietary Cu levels increased total and Cu/Zn SOD activity for lactating sows (linear, P < 0.05). Sows fed TBCC diets had lower concentrations of Cu (P = 0.04), but higher concentrations of iron and manganese (P < 0.05) in the liver, when compared to those fed with CuSO4 diets. In addition, liver Cu concentrations increased with increasing dietary Cu levels (linear and quadratic, P < 0.05). Increasing dietary Cu levels resulted in the elevation of concentrations and contents of Cu in the liver of weanling piglets (linear, P < 0.0001). In the nursery pig experiment, pigs from sows fed 120 mg/kg Cu diets had greater ADG from d 0 to 14 (P < 0.05), and tended to have greater ADG in the overall period (P < 0.08), when compared to pigs from sows fed 20 mg/kg Cu diets. During the lipopolysaccharide challenge period, the challenged pigs from sows fed 120 mg/kg Cu had a greater overall rectal temperature than those from sows fed 20 mg/kg Cu (P = 0.01). Also, the challenged pigs fed with 220 mg/kg Cu diets had greater serum tumor necrosis factor-alpha concentration over time as compared to those fed 20 mg/kg Cu diets (P = 0.03). In summary, the TBCC may be a superior Cu source compared to CuSO4 regarding reproductive performance, and higher dietary Cu levels result in greater birth weight of piglets; furthermore, high Cu levels in sow and nursery diets promote growth performance of nursery pigs and affects their responses to immunological challenge.

Two studies were conducted to evaluate the effectiveness of using copper sulfate (CuSO4) as a drench in Hampshire ewes to control stomach worms (Haemonchus contortus). A study was conducted to assess the effectiveness of CuSO4 to control gastrointestinal nematodes (GIN) over a three year period. Ewes were FAMACHA scored, hematocrit evaluated for packed cell volume (PCV), and fecal egg counts (FEC) were determined from 2007 through 2009. Ewes received only CuSO4 to control GIN. Ewes with FEC exceeding 6,000 eggs/g feces were drenched. A separate study during the summer of 2008 assessed the potential of CuSO4 drench to cause copper toxicity in Hampshire ewes. Eighty-four ewes were blocked to one of two treatments according to parity and balanced for FEC. One group received CuSO4 (D) and the other was not drenched (ND). Jugular blood samples were collected at pre-determined intervals after CuSO4 was administered to D ewes. Serum was analyzed for aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine kinase (CK). Elevated serum levels indicate copper toxicity. Results suggest CuSO4 has the potential to control stomach worms in Hampshire ewes without causing copper toxicity.

Thesis (M.S.)--University of Alabama at Birmingham, 2008. / Additional advisors: Marion Nipper, Robert A. Angus, Addison L. Lawrence. Description based on contents viewed May 30, 2008; title from title screen. Includes bibliographical references.

Esta tese foi conduzida com o objetivo de avaliar a exigência do micromineral cobre para matrizes de frangos de corte. Cento e vinte reprodutoras de frangos de corte Cobb 500, com 20 semanas de idade, foram distribuídas aleatoriamente em gaiolas individuais. Depois de alimenta-las por 4 semanas com a dieta deficiente em cobre, as galinhas receberam dietas com níveis graduados de suplementação de cobre (0,0; 3,5; 7,0; 10,5; 14, and 17,5 ppm), utilizando sulfato de cobre (CuSO4 5H2O), totalizando níveis de 2,67; 5,82; 9,38; 12,92; 16,83; 20,19 ppm de cobre analisado na dieta por 20 semanas. As estimativas da exigência de cobre foram feitas utilizando os modelos: exponencial assimptótico (EA), broken line com quadrática (BLQ), e quadrática polinomial (QP). Os requerimentos de cobre obtidos para a produção de ovos (%) e produção total de ovos incubáveis por galinha foram 6,2, 7,3, 12,9 ppm e 8,1, 9,0 e 13,4 ppm, respectivamente usando os modelos EA, BLQ e QP. O modelo QP foi o único que se ajustou para o número total de ovos por galinha, fornecendo 13,1 ppm de cobre como requerimento. A hemoglobina, hematócrito e concentração de cobre no soro das galinhas tiveram os requerimentos estimados em 13,9, 11,3, 18,5 ppm, e 14,6, 13,0, 19,0 ppm, e16,2, 14,6 e 14,2 ppm, respectivamente para os modelos EA, BLQ e QP. O modelo QP foi o único que se ajustou para o número total de ovos por galinha, fornecendo 13,1 ppm de cobre como requerimento. A hemoglobina, hematócrito e concentração de cobre no soro das galinhas tiveram os requerimentos estimados em 13,9, 11,3, 18,5 ppm, e 14,6, 13,0, 19,0 ppm, e16,2, 14,6 e 14,2 ppm, respectivamente para os modelos EA, BLQ e QP. A hemoglobina dos pintos recém-eclodidos não foi afetada pelos níveis de cobre da dieta, enquanto os requerimentos para o hematócrito, peso corporal e comprimento foram de 10,2, 12,3, 13,3 ppm usando os modelos EA, BLQ e QP, e 6,8, 7,1 ppm e 12,9, 13,9 ppm utilizando os modelos EA, BLQ e QP, respectivamente. A máxima resposta para peso do ovo, conteúdo de cobre na gema, espessura da membrana da casca do ovo foram obtidas usando 14,9, 12,7, 15,1 ppm, 15,0, 16,3, 15,7 ppm, e 7,3 7,8, 14,0 ppm de cobre, respectivamente para os modelos EA, BLQ e QP. As porcentagens de gema e albúmen foram ajustadas apenas pelo modelo QP e obtiveram requerimentos estimados em 11 ppm e 11,3 ppm, respectivamente, enquanto a espessura da camada mamilar da casca do ovo foi maximizada com 10,6, 10,1 e 14,4 ppm de cobre usando os modelos EA, BLQ e QP, respectivamente. A média de todos os requerimentos de cobre estimados no presente estudo foi 12,5 ppm. / This thesis was conducted with the objective of evaluating the Cu requirement of broiler breeder hens. One hundred and twenty Cobb 500 hens, 20 weeks of age were randomly allocated into individual cages with the objective of estimating Cu requirements. After being fed a Cu deficient diet for 4 wks, hens were fed diets graded increments of supplemental Cu (0.0; 3.5; 7.0; 10.5; 14, and 17.5 ppm) from Cu sulfate (CuSO4 5H2O), totalizing 2.67; 5.82; 9.38; 12.92; 16.83; 20.19 ppm analyzed Cu in feeds for 20 wks. Estimations of Cu requirements were done using exponential asymptotic (EA), broken line quadratic (BLQ), and quadratic polynomial (QP) models. Cu requirements obtained for hen day egg production and total settable eggs per hen were 6.2, 7.3, 12.9 ppm and 8.1, 9.0 and 13.4 ppm, respectively using EA, BLQ and QP models. The QP model was the only one having a fit for total eggs per hen with 13.1 ppm Cu as requirement. Hemoglobin, hematocrit and serum Cu from hens had requirements estimated as 13.9, 11.3, 18.5 ppm and 14.6, 13.0, 19.0 ppm and 16.2, 14.6, 14.2 ppm, respectively for EA, BLQ and QP models. Hatching chick hemoglobin was not affected by dietary Cu whereas requirements estimated for hatching chick hematocrit, body weight and length were 10.2, 12.3, 13.3 ppm using EA, BLQ and QP models, and 6.8, 7.1 ppm and 12.9, 13.9 ppm Cu using EA and BLQ models, respectively. Maximum responses for egg weight, yolk Cu content, and eggshell membrane thickness were 14.9, 12.7, 15.1 ppm, 15.0, 16.3, 15.7 ppm and 7.3, 7.8, 14.0 ppm Cu, respectively for EA, BLQ and QP models. Yolk and albumen percentage were only adjusted with the QP model and had requirements estimated at 11.0 ppm and 11.3 ppm, respectively, whereas eggshell mammillary layer was maximized with 10.6, 10.1 and 14.4 ppm Cu using EA, BLQ and QP models, respectively. The average of all Cu requirement estimates obtained in the present study was 12.5 ppm Cu.

Esta tese foi conduzida com o objetivo de avaliar a exigência do micromineral cobre para matrizes de frangos de corte. Cento e vinte reprodutoras de frangos de corte Cobb 500, com 20 semanas de idade, foram distribuídas aleatoriamente em gaiolas individuais. Depois de alimenta-las por 4 semanas com a dieta deficiente em cobre, as galinhas receberam dietas com níveis graduados de suplementação de cobre (0,0; 3,5; 7,0; 10,5; 14, and 17,5 ppm), utilizando sulfato de cobre (CuSO4 5H2O), totalizando níveis de 2,67; 5,82; 9,38; 12,92; 16,83; 20,19 ppm de cobre analisado na dieta por 20 semanas. As estimativas da exigência de cobre foram feitas utilizando os modelos: exponencial assimptótico (EA), broken line com quadrática (BLQ), e quadrática polinomial (QP). Os requerimentos de cobre obtidos para a produção de ovos (%) e produção total de ovos incubáveis por galinha foram 6,2, 7,3, 12,9 ppm e 8,1, 9,0 e 13,4 ppm, respectivamente usando os modelos EA, BLQ e QP. O modelo QP foi o único que se ajustou para o número total de ovos por galinha, fornecendo 13,1 ppm de cobre como requerimento. A hemoglobina, hematócrito e concentração de cobre no soro das galinhas tiveram os requerimentos estimados em 13,9, 11,3, 18,5 ppm, e 14,6, 13,0, 19,0 ppm, e16,2, 14,6 e 14,2 ppm, respectivamente para os modelos EA, BLQ e QP. O modelo QP foi o único que se ajustou para o número total de ovos por galinha, fornecendo 13,1 ppm de cobre como requerimento. A hemoglobina, hematócrito e concentração de cobre no soro das galinhas tiveram os requerimentos estimados em 13,9, 11,3, 18,5 ppm, e 14,6, 13,0, 19,0 ppm, e16,2, 14,6 e 14,2 ppm, respectivamente para os modelos EA, BLQ e QP. A hemoglobina dos pintos recém-eclodidos não foi afetada pelos níveis de cobre da dieta, enquanto os requerimentos para o hematócrito, peso corporal e comprimento foram de 10,2, 12,3, 13,3 ppm usando os modelos EA, BLQ e QP, e 6,8, 7,1 ppm e 12,9, 13,9 ppm utilizando os modelos EA, BLQ e QP, respectivamente. A máxima resposta para peso do ovo, conteúdo de cobre na gema, espessura da membrana da casca do ovo foram obtidas usando 14,9, 12,7, 15,1 ppm, 15,0, 16,3, 15,7 ppm, e 7,3 7,8, 14,0 ppm de cobre, respectivamente para os modelos EA, BLQ e QP. As porcentagens de gema e albúmen foram ajustadas apenas pelo modelo QP e obtiveram requerimentos estimados em 11 ppm e 11,3 ppm, respectivamente, enquanto a espessura da camada mamilar da casca do ovo foi maximizada com 10,6, 10,1 e 14,4 ppm de cobre usando os modelos EA, BLQ e QP, respectivamente. A média de todos os requerimentos de cobre estimados no presente estudo foi 12,5 ppm. / This thesis was conducted with the objective of evaluating the Cu requirement of broiler breeder hens. One hundred and twenty Cobb 500 hens, 20 weeks of age were randomly allocated into individual cages with the objective of estimating Cu requirements. After being fed a Cu deficient diet for 4 wks, hens were fed diets graded increments of supplemental Cu (0.0; 3.5; 7.0; 10.5; 14, and 17.5 ppm) from Cu sulfate (CuSO4 5H2O), totalizing 2.67; 5.82; 9.38; 12.92; 16.83; 20.19 ppm analyzed Cu in feeds for 20 wks. Estimations of Cu requirements were done using exponential asymptotic (EA), broken line quadratic (BLQ), and quadratic polynomial (QP) models. Cu requirements obtained for hen day egg production and total settable eggs per hen were 6.2, 7.3, 12.9 ppm and 8.1, 9.0 and 13.4 ppm, respectively using EA, BLQ and QP models. The QP model was the only one having a fit for total eggs per hen with 13.1 ppm Cu as requirement. Hemoglobin, hematocrit and serum Cu from hens had requirements estimated as 13.9, 11.3, 18.5 ppm and 14.6, 13.0, 19.0 ppm and 16.2, 14.6, 14.2 ppm, respectively for EA, BLQ and QP models. Hatching chick hemoglobin was not affected by dietary Cu whereas requirements estimated for hatching chick hematocrit, body weight and length were 10.2, 12.3, 13.3 ppm using EA, BLQ and QP models, and 6.8, 7.1 ppm and 12.9, 13.9 ppm Cu using EA and BLQ models, respectively. Maximum responses for egg weight, yolk Cu content, and eggshell membrane thickness were 14.9, 12.7, 15.1 ppm, 15.0, 16.3, 15.7 ppm and 7.3, 7.8, 14.0 ppm Cu, respectively for EA, BLQ and QP models. Yolk and albumen percentage were only adjusted with the QP model and had requirements estimated at 11.0 ppm and 11.3 ppm, respectively, whereas eggshell mammillary layer was maximized with 10.6, 10.1 and 14.4 ppm Cu using EA, BLQ and QP models, respectively. The average of all Cu requirement estimates obtained in the present study was 12.5 ppm Cu.

No description available.

Proteomic techniques were used to analyze the protein profile of earthworm, Lumbricus terrestris, coelomic fluid collected by either whole body dissection method or the coelomic cavity puncture method. Data demonstrated that collection of coelomic fluid using the coelomic cavity puncture method protocol resulted in a 32% reduction, 377 +/- 4.5 vs 253+/- 19.9 (p=0.0007), in the number of individual proteins. It was determined that the coelomic cavity puncture method yielded a "cleaner" preparation, one less contaminated with extraneous proteins from intestinal tissue, gut contents, and body wall materials. This protocol was used in all later studies. The same proteomic techniques were used to evaluate the effects that exposure to Cu (1.0 &#956;g/cm2) as CuSO4 had on the earthworm coelomic fluid profile. Comparison of protein profile from exposed earthworms demonstrated a significant reduction in the number of proteins expressed (184 ± 2.64 vs 253 ±19.9 p=0.0192) when compared to control organisms. Cu exposure also resulted in a modulation of the protein profile with treated earthworms expressing 47 new proteins that were not identified in unexposed worm coelomic fluid. Additionally, 116 proteins found in coelomic fluid collected from normal worms were absent in Cu exposed organisms. Finally, 137 proteins were conserved or found in both control and exposed organisms; however of these proteins, 24 were up-regulated, 105 were down-regulated, and 8 were unchanged as a result of Cu exposure.

No description available.

No description available.

Erwinia amylovora, a quarantine organism of the European Union (EU), is the causal agent of fire blight. This disease causes substantial economic losses in all countries where it is present and its control turns out difficult, due to the absence of effective chemical and biological treatments and the ability of persistence and dissemination of E. amylovora. Cupric treatments constitute the base of the integrated management of fire blight in the European Union countries, because the antibiotics, although have been proved useful against this disease, are forbidden in the EU for plant treatments. This thesis, mostly performed in a P2 security lab, is aimed to dilucidate molecular mechanisms implicated in the response of E. amylovora to copper sulfate as a stress factor, considering that copper is a well known toxic element for bacterial cells over a certain threshold concentration. The global objective was first addressed with the study of a selection of genes that have been related in other bacterial models with copper stress or with stress in general. The quantification of the rpoS gene expression in presence of copper showed that, at least in long-term survival, this gene may be involved in the E. amylovora response to copper stress. Second, a transcriptomic study was performed by microarray after subdue the bacteria to a copper shock treatment. The analysis of the microarray results showed that 44 genes were differentially expressed in presence of this metal. Each one of these genes was studied by gene ontology and, after comparing them with databases published in NCBI, they were classified in functional categories. The gene expression of twenty-five out of fourty-four differentially expressed genes was validated by real-time PCR. In the validation, copA gene was expressed more than 19-fold in presence than in absence of copper and, because of that, it was selected together with other seven genes (soxS, yjcE, ygcF, yhhQ, galF, arcB, EAM_3469), which also showed an increased expression, to generate mutants of E. amylovora. The responses of mutants to copper, and the fact that the wild phenotype was restored in the complemented mutants, has shown the role of copA, soxS, yjcE, ygcF, arcB and yhhQ genes in the E. amylovora in vitro survival against copper stress. Besides, the implication of copA gene has also been proved in planta, in copper treated shoots from pear trees. Finally, all the results obtained along this thesis have allowed to elaborate a putative model of the different genetic mechanisms that seem are involved in the interaction between E. amylovora and copper. The most important mechanism seems to be to face up reactive oxygen species (ROS) by the activation of the soxS and yjcE genes. The activity of these genes is supported by CopA protein, which pumps copper from inside the cell out to the periplasmic space. The activation of arcB gene, which allows the change from aerobic metabolism to anaerobic metabolism, would also help E. amylovora to reduce ROS. Taking together, the results of this thesis have allowed an approximation to the genetic basis of E. amylovora response to copper stress and they constitute a start point to move forward in the knowledge of the molecular mechanisms underlying that response. / Erwinia amylovora, organismo de cuarentena en la Unión Europea (UE), es el agente causal del fuego bacteriano. Esta enfermedad produce grandes pérdidas económicas en todos los países en los que está presente y su control resulta muy difícil, debido a la carencia de tratamientos químicos y biológicos eficaces y a la persistencia y facilidad de diseminación de E. amylovora. Los tratamientos con compuestos cúpricos constituyen la base de la gestión integrada del fuego bacteriano en los países de la UE, puesto que el uso de antibióticos, aunque se ha demostrado útil contra esta enfermedad, está prohibido en la UE para el tratamiento de bacteriosis en plantas. Esta tesis, realizada en su mayoría en un laboratorio de seguridad biológica P2, pretende dilucidar mecanismos moleculares implicados en la respuesta de E. amylovora al sulfato de cobre como factor de estrés, ya que este metal es un elemento tóxico para las células bacterianas por encima de una determinada concentración umbral. El objetivo global se abordó, en primer lugar, con el estudio de una selección de genes que se han relacionado en otros modelos bacterianos con el estrés que produce el cobre o con el estrés en general. La cuantificación de la expresión del gen rpoS en presencia de cobre mostró que este gen puede estar implicado en la supervivencia a largo plazo de E. amylovora para combatir el estrés que produce este metal. En una segunda aproximación, se realizó un estudio transcriptómico mediante microarray tras someter a la bacteria a un breve tratamiento de cobre. El análisis de los resultados del microarray reveló que 44 genes se expresaban de forma diferencial en presencia del metal. Cada uno de ellos se estudió mediante gene ontology y por comparación con las bases de datos publicadas en el NCBI, y así se clasificaron en categorías funcionales. Las categorías de estrés y transporte fueron las más abundantes, tanto respecto a los genes que aumentaron su expresión tras la aplicación de cobre como a los que la disminuyeron. De los 44 genes que se expresaron de forma diferencial, se validó la expresión de 25 de ellos por PCR en tiempo real. En dicha validación, el gen copA se expresó 19 veces más en presencia que en ausencia de cobre, por lo que fue seleccionado, junto con siete genes más (soxS, yjcE, ygcF, yhhQ, galF, arcB, EAM_3469), en los que el incremento en la expresión fue menos pronunciado, para generar mutantes de E. amylovora. La respuesta de los mutantes a la presencia de cobre, y la restauración de fenotipos al complementar las mutaciones generadas, han revelado el papel de los genes copA, soxS, yjcE, ygcF, arcB y yhhQ en la supervivencia in vitro de E. amylovora frente al estrés por cobre. Además, la implicación del gen copA se ha demostrado también in planta en brotes de peral tratados con cobre. Finalmente, todos los resultados obtenidos han permitido elaborar un posible modelo de los diferentes mecanismos genéticos que parecen estar implicados en la interacción de E. amylovora con el cobre. El mecanismo más importante parece ser combatir las especies reactivas del oxígeno (ERO), mediante la activación de la expresión de los genes soxS e yjcE. La actividad de estos genes está apoyada, además, por la proteína CopA, que bombea cobre desde el interior celular al espacio periplásmico. La activación del gen arcB, que permite el cambio de un metabolismo aerobio a uno anaerobio, también ayudaría a la reducción de las ERO. En definitiva, los resultados han permitido una aproximación al sustrato genético de la respuesta de E. amylovora al estrés por cobre, y constituyen un punto de partida para avanzar en el conocimiento de los mecanismos moleculares implicados en dicha respuesta. / E. amylovora, organisme de quarantena a la Unió Europea (UE), és l'agent causal del foc bacterià. Aquesta malaltia produeix grans pèrdues econòmiques a tots els països on està present, i el seu control resulta molt difícil, a causa de l' absència de productes químics i biològics eficaços i també per la capacitat de persistència i disseminació d'E. amylovora. Els tractaments amb composts cúprics constitueixen la base de la gestió integrada del foc bacterià als països europeus, ja que l'ús d'antibiòtics, tot i que s'ha demostrat eficaç per a combatre aquesta malaltía, està prohibit a la UE per al tractament de bacteriosi en plantes. Aquesta tesi, realitzada majoritàriament a un laboratori de seguretat biològica P2, pretén dilucidar mecanismes moleculars implicats en la resposta d'E. amylovora davant del coure com a factor d'estrés, ja que el coure és un element tòxic per la cèl.lula per damunt d'una determinada concentració umbral. L'objectiu global es va abordar, en primer lloc, amb l'estudi d'una selecció de gens relacionats en altres models bacterians amb l'estrés que produeix el coure, o amb l'estrés en general. La quantificació de l'expressió del gen rpoS en presència de coure va mostrar que aquest gen pot estar implicat en la supervivència a llarg termini d'E. amylovora per a combatre l'estrés que produeix aquest metall. En una segona aproximació, es va realitzar un estudi transcriptòmic mitjançant microarrays després de sotmetre els bacteris a un breu tractament de coure. L'anàlisi dels resultats dels microarrays va revelar que 44 gens s'expressen de forma diferencial en presència del metall. Cadascun d'ells es va estudiar mitjançant gene ontology i, per comparació amb les bases de dades publicades al NCBI, es van classificar en categories funcionals. Les categories d'estrés i transport van ser les més enriquides, tant en els gens que augmentaren la seua expressió després de l'aplicació de coure com en aquells que la van reduir. Dels 44 gens que s'expressaren de forma diferencial, es va validar l'expressió de 25 d'ells per PCR a temps real. En la validació, el gen copA es va expressar 19 vegades més en presència que en absència de coure, per aquesta raó va ser seleccionat junt amb set gens més (soxS, yjcE, ygcF, yhhQ, galF, arcB, EAM_3469), en els que l'increment de l'expressió va ser menys pronunciada, per a generar mutants d'E. amylovora. La resposta dels mutants a la presència de coure, i la restauració dels fenotips originals al complementar les mutacions generades, han revelat el paper dels gens copA, soxS, yjcE, ygcF, arcB i yhhQ en la supervivència in vitro d'E. amylovora davant a l'estrés per coure. A més a més, la implicació del gen copA s'ha demostrat també in planta, en brots de perera tractats amb coure. Finalment, tots els resultats obtinguts han permès elaborar un possible model dels diferents mecanismes genètics que semblen estar implicats en la interacció d'E. amylovora amb el coure. El mecanisme més important sembla ser combatre les especies reactives de l'oxigen (ERO), mitjançant l'activació de l'expressió dels gens soxS i yjcE. L'activitat d'aquestos gens és recolzada també per l'acció de la proteïna copA, que bombeja coure des de l'interior cel.lular a l'espai periplàsmic. L'activació del gen arcB, que permet el canvi d'un metabolisme aerobi a un metabolisme anaerobi, també ajudaria a reduir la producción de les ERO. En conclusió, els resultats han suposat una aproximació al substrat genètic de la resposta d'E. amylovora a l'estrés per coure, i constitueixen un punt de partida per avançar en el coneixement dels mecanismes moleculars implicats en aquesta resposta. / Águila Clares, B. (2017). Elucidating the molecular basis of copper stress in Erwinia amylovora [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/81658