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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Biocontrole de fungos fitopatogênicos por actinobactérias isoladas de rizosfera de Araucaria angustifolia / Biocontrol of phytopathogenic fungi by actinobacteria isolated from rhizosphere of Araucaria angustifolia

Marina Yumi Horta Miyauchi 02 March 2012 (has links)
Algumas actinobactérias habitantes da rizosfera são produtoras de substâncias capazes de combater micro-organismos patogênicos às plantas, o que as torna potenciais agentes de controle biológico, passíveis de serem utilizadas como princípio ativo de inoculantes de sementes e mudas. O presente trabalho teve como objetivo isolar e avaliar o potencial de isolados de actinobactérias no controle de doenças causadas por fungos nas espécies arbóreas Araucaria angustifolia (Araucária) e Pinus elliottii (Pinus). Além disso, foi iniciado o estudo do processo de elaboração de inoculante a base de actinobactérias antagônicas. Foram isoladas 215 estirpes de actinobactérias do rizoplano da Araucária, das quais 13 apresentaram, em testes in vitro, potencial como antagonistas contra os fungos fitopatogênicos Fusarium oxysporum, Cylindrocladium candelabrum, C. pteridis e Armillaria sp., e apenas os isolados Ac136 e Ac202 apresentaram os maiores valores de inibição nos testes com os quatro patógenos. Na avaliação de produção de algumas substâncias antimicrobianas, apenas celulases, quitinases e sideróforos foram produzidas pelos isolados, sendo este último o mais frequente. Nos testes de interação com organismos foi verificado que, embora os isolados de actinobactéria tenham inibido a germinação de esporos do fungo micorrízico arbuscular (FMA) Gigaspora rosea em teste in vitro, no experimento in vivo, em que foi utilizado o milho como planta hospedeira para inoculação com o FMA e os isolados A43, Ac136 e Ac202, os isolados Ac136 e Ac202 estimularam a colonização das raízes pelo FMA. Estes mesmos isolados também estimularam a germinação de sementes e desenvolvimento inicial de plântulas de Pinus, porém prejudicaram a germinação e desenvolvimento inicial de Araucária. Estes mesmos isolados foram capazes de reduzir a mortalidade de plântulas de Pinus em cerca de 25%, e esta diminuição foi atribuída à inibição de Fusarium sp.. No teste de viabilidade dos isolados em diferentes veículos o isolado que mostrou maior sobrevivência foi o Ac202, mantendo um número de propágulos viáveis correspondente a 5,48 log UFC mL-1, enquanto que o veículo mais apropriado para a elaboração de inoculante com actinobactérias foi a glicerina. A análise molecular mostrou que os isolados mais promissores apresentaram maior similaridade com S. kasugaensis. Dentre todos isolados Ac202 (S. kasugaensis) foi o mais promissor obtido neste trabalho para o uso como agente de biocontrole de doenças causadas por fungos, apresentando forte antagonismo contra os quatro patógenos testados, promovendo a germinação e desenvolvimento inicial de Pinus e aumentando a sobrevivência de plântulas contaminadas com fungos fitopatogênicos. / Some actinobacteria that inhabits the rhizosphere are producers of substances that are capable of combating plant-pathogenic microorganisms, what makes them potential biological control agents, which can be used as the active ingredient of seeds and seedlings inoculants. This study aimed to isolate and evaluate the potential of actinobacteria isolates in controlling diseases caused by fungi in Araucaria angustifolia and Pinus elliottii. In addition, the study initiated the process of elaboration of an actinobacteria-based inoculant. 215 actinobacterial strains were isolated from the Araucarias rhizoplane, and 13 of them showed potential as antagonists against the phytopathogenic fungi Fusarium oxysporum, Cylindrocladium candelabrum, C. pteridis and Armillaria sp. in in vitro tests, and only the Ac136 and Ac202 strains showed the highest inhibition in the tests against the four pathogens. Among the antimicrobial substances tested, only cellulases, chitinases and siderophores were produced, with the latter being the most frequent. In the interaction tests with other organisms it was found that although the actinobacterial strains have inhibited the germination of the arbuscular mycorrhizal fungi (AMF) Gigaspora rosea spores on the in vitro test, the in vivo experiment, with maize as host plant, inoculated with the AMF and A43, Ac136 and Ac202 actinobacterial strains, Ac136 and Ac202 stimulated root colonization by AMF. These strains also stimulated Pinus seed germination and seedling early development, but hindered the germination and early development of Araucaria. In addition, the same strains were able to reduce the mortality of pine seedlings by about 25%, and this decrease was attributed to the inhibition of Fusarium sp.. In the viability test of the strains in different vehicles the strain that showed the greatest shelf-life was Ac202, with 5.48 log CFU mL-1, and the most appropriate vehicle for the actinobacteriabased inoculant development was glycerin. Molecular analysis showed that the most promising isolates showed the greatest similarity with S. kasugaensis. Among all strains Ac202 (S. kasugaensis) was the most promising one for the use as biocontrol agent of fungal diseases, exhibiting a strong antagonism against the four pathogens tested, promoting germination and early development of Pinus and increasing survival of seedlings infected with pathogenic fungi.
62

Influência da origem do inóculo e da adição de sulfato sobre a degradação de BTX em reator anaeróbio horizontal de leito fixo / Influence of different inoculum sources and sulphate addition on anaerobic BTX degradation in a packed-bed reactor

Bruna Soares Fernandes 11 March 2005 (has links)
O desenvolvimento industrial tem, como conseqüência, a maior geração de resíduos, muitos deles tóxicos aos seres vivos. Dentre esses, benzeno, tolueno e xilenos (BTX), derivados do petróleo, estão contaminando aqüíferos por acidentes no transporte e no armazenamento. Por esse motivo, diversas pesquisas têm sido realizadas buscando formas de biodegradar BTX. Esses trabalhos indicam que os principais fatores que podem influenciar a degradação biológica dos BTX são temperatura, pH, disponibilidade de nutrientes, concentração de tóxicos e diversidade de microrganismos. Visando contribuir com o estudo desses fatores, este trabalho teve por objetivo avaliar a influência do inóculo e de aceptores de elétrons no processo de degradação anaeróbia de BTX. Neste trabalho três inóculos foram pesquisados: 1- biomassa proveniente de reator anteriormente submetido à mistura de gasolina comercial e água; 2- biomassa proveniente de reator da estação de tratamento de esgoto da USP - São Carlos; 3- biomassa proveniente de reator tratando água residuária de abatedouro de aves. Os resultados obtidos comprovaram que a origem do inóculo foi fundamental na degradação anaeróbia de BTX, pois os inóculos apresentaram diferentes períodos de adaptação e porcentagens de degradação do tóxico. Depois de 93 dias de operação os inóculos 1, 2 e 3 apresentaram eficiência de remoção de BTX da ordem de 57%, 83% e 90%, respectivamente. O reator com o inóculo 3 foi submetido a condições metanogênica, sulfetogênica com presença e ausência de Ferro (III). Os resultados demonstraram que a degradação dos BTX foi influenciada pelas diferentes condições adotadas. A adição de Fe (III) melhorou a degradação dos BTX, do reator sob condições sulfetogênicas. / The industrial development has increased the generation of residues. Some of them are toxics and impact the environment. Benzene, toluene and xylenes (BTX), petroleum sub products, are examples of such toxic compounds. These compounds may contaminate aquifers as a result of accidents during transportation or of leakages of storage tanks. Several factors are reported to affect the biodegradation of BTX, such as: temperature, pH, availability of nutrients, concentration of toxics and diversity of microorganisms. This research aimed to study some of these factors, such as different inoculum sources and different electrons acceptors during BTX degradation processes in an horizontal-flow anaerobic immobilized biomass (HAIB) reactor. In this research three inocula were studied: 1- an adapted microbial community for BTX degradation; 2 - microorganisms collected from a pilot-scale UASB reactor treating domestic wastewater; and 3 - Microorganisms collected from an UASB treating poultry slaughterhouse industry wastewater. The results have shown that the inoculum sources were fundamental to the adaptation period for the toxic biodegradation, producing different BTX removal efficiencies. After 93 days of operation, the inocula 1, 2 and 3 showed BTX removal efficiency of 57, 83 and 90%, respectively. The inoculum 3 was submitted to conditions of methanogesis and sulfetogenesis in the presence and absence of Fe (III). The results demonstrated that BTX degradation was affected by the different conditions adopted, showing that the addition of Fe (III) improved biodegradation in the reactor under sulfate reduction condition.
63

Biocontrole de fungos fitopatogênicos por actinobactérias isoladas de rizosfera de Araucaria angustifolia / Biocontrol of phytopathogenic fungi by actinobacteria isolated from rhizosphere of Araucaria angustifolia

Miyauchi, Marina Yumi Horta 02 March 2012 (has links)
Algumas actinobactérias habitantes da rizosfera são produtoras de substâncias capazes de combater micro-organismos patogênicos às plantas, o que as torna potenciais agentes de controle biológico, passíveis de serem utilizadas como princípio ativo de inoculantes de sementes e mudas. O presente trabalho teve como objetivo isolar e avaliar o potencial de isolados de actinobactérias no controle de doenças causadas por fungos nas espécies arbóreas Araucaria angustifolia (Araucária) e Pinus elliottii (Pinus). Além disso, foi iniciado o estudo do processo de elaboração de inoculante a base de actinobactérias antagônicas. Foram isoladas 215 estirpes de actinobactérias do rizoplano da Araucária, das quais 13 apresentaram, em testes in vitro, potencial como antagonistas contra os fungos fitopatogênicos Fusarium oxysporum, Cylindrocladium candelabrum, C. pteridis e Armillaria sp., e apenas os isolados Ac136 e Ac202 apresentaram os maiores valores de inibição nos testes com os quatro patógenos. Na avaliação de produção de algumas substâncias antimicrobianas, apenas celulases, quitinases e sideróforos foram produzidas pelos isolados, sendo este último o mais frequente. Nos testes de interação com organismos foi verificado que, embora os isolados de actinobactéria tenham inibido a germinação de esporos do fungo micorrízico arbuscular (FMA) Gigaspora rosea em teste in vitro, no experimento in vivo, em que foi utilizado o milho como planta hospedeira para inoculação com o FMA e os isolados A43, Ac136 e Ac202, os isolados Ac136 e Ac202 estimularam a colonização das raízes pelo FMA. Estes mesmos isolados também estimularam a germinação de sementes e desenvolvimento inicial de plântulas de Pinus, porém prejudicaram a germinação e desenvolvimento inicial de Araucária. Estes mesmos isolados foram capazes de reduzir a mortalidade de plântulas de Pinus em cerca de 25%, e esta diminuição foi atribuída à inibição de Fusarium sp.. No teste de viabilidade dos isolados em diferentes veículos o isolado que mostrou maior sobrevivência foi o Ac202, mantendo um número de propágulos viáveis correspondente a 5,48 log UFC mL-1, enquanto que o veículo mais apropriado para a elaboração de inoculante com actinobactérias foi a glicerina. A análise molecular mostrou que os isolados mais promissores apresentaram maior similaridade com S. kasugaensis. Dentre todos isolados Ac202 (S. kasugaensis) foi o mais promissor obtido neste trabalho para o uso como agente de biocontrole de doenças causadas por fungos, apresentando forte antagonismo contra os quatro patógenos testados, promovendo a germinação e desenvolvimento inicial de Pinus e aumentando a sobrevivência de plântulas contaminadas com fungos fitopatogênicos. / Some actinobacteria that inhabits the rhizosphere are producers of substances that are capable of combating plant-pathogenic microorganisms, what makes them potential biological control agents, which can be used as the active ingredient of seeds and seedlings inoculants. This study aimed to isolate and evaluate the potential of actinobacteria isolates in controlling diseases caused by fungi in Araucaria angustifolia and Pinus elliottii. In addition, the study initiated the process of elaboration of an actinobacteria-based inoculant. 215 actinobacterial strains were isolated from the Araucarias rhizoplane, and 13 of them showed potential as antagonists against the phytopathogenic fungi Fusarium oxysporum, Cylindrocladium candelabrum, C. pteridis and Armillaria sp. in in vitro tests, and only the Ac136 and Ac202 strains showed the highest inhibition in the tests against the four pathogens. Among the antimicrobial substances tested, only cellulases, chitinases and siderophores were produced, with the latter being the most frequent. In the interaction tests with other organisms it was found that although the actinobacterial strains have inhibited the germination of the arbuscular mycorrhizal fungi (AMF) Gigaspora rosea spores on the in vitro test, the in vivo experiment, with maize as host plant, inoculated with the AMF and A43, Ac136 and Ac202 actinobacterial strains, Ac136 and Ac202 stimulated root colonization by AMF. These strains also stimulated Pinus seed germination and seedling early development, but hindered the germination and early development of Araucaria. In addition, the same strains were able to reduce the mortality of pine seedlings by about 25%, and this decrease was attributed to the inhibition of Fusarium sp.. In the viability test of the strains in different vehicles the strain that showed the greatest shelf-life was Ac202, with 5.48 log CFU mL-1, and the most appropriate vehicle for the actinobacteriabased inoculant development was glycerin. Molecular analysis showed that the most promising isolates showed the greatest similarity with S. kasugaensis. Among all strains Ac202 (S. kasugaensis) was the most promising one for the use as biocontrol agent of fungal diseases, exhibiting a strong antagonism against the four pathogens tested, promoting germination and early development of Pinus and increasing survival of seedlings infected with pathogenic fungi.
64

Enhancing ecosystem services in vineyards to improve the management of Botrytis cinerea

Jacometti, Marco Alexander Azon January 2007 (has links)
Organic mulches and cover crops mulched in situ were assessed for their effects on B. cinerea primary inoculum and disease levels in inflorescences at flowering and/or bunches at harvest. Organic mulches were used to enhance biological degradation of vine debris to reduce levels of B. cinerea primary inoculum the following season. Four mulch types (anaerobically and aerobically fermented marc (grape pressings), inter-row grass clippings and shredded office paper) were applied under ten-year-old Riesling vines in a ten-replicate randomized block design in New Zealand over two consecutive years. Plastic mesh bags, each containing naturally infected vine debris, were placed under vines on bare ground (control) and at the soil-mulch interface, in winter (July) 2003 and 2004. In each year, half the bags were recovered at flowering (December) and the remainder at leaf plucking (February), for assessment of B. cinerea sporulation from the vine debris and debris degradation rate. Bait lamina probes, which measure soil biological activity, were placed in the soil-mulch interface three weeks before each of the two bag-recovery dates in both years and were then removed and assessed at the same times as were the bags. All mulches led to a reduction in B. cinerea sporulation. This reduction was significantly correlated with elevated rates of vine debris decomposition and increased soil biological activity. Over both years, compared with the controls, all treatments gave a 3-20-fold reduction in B. cinerea sporulation, a 1.6-2.6-fold increase in vine debris degradation and in the two marc and the paper treatments, a 1.8-4-fold increase in activity of soil organisms. The mulches also altered vine characteristics and elevated their resistance to B. cinerea through changes to the soil environment. Functional soil biological activity, as measured by Biolog Ecoplates and bait lamina probes, was increased 2-4 times in the two marc and paper treatments, compared with the control, an effect relating to the elevated soil moisture and reduced temperature fluctuations under these mulches. Soil nutrient levels and the C:N ratios were also affected in these treatments. The mulched paper lowered vine canopy density by up to 1.4 times that of the other treatments, an effect which probably led to elevated light penetration into the canopy and consequent increased canopy temperature, photosynthesis and lowered canopy humidity. These changes to soil and vine characteristics increased grape skin strength by up to 10% in the paper treatment and sugar concentrations by 1.2-1.4 °Brix in the two marc and paper treatments. The severity of B. cinerea infections in the anaerobic marc, aerobic marc and paper treatments were reduced to 12%, 3% and 2.2% of the control, respectively, in field assessments averaged over two consecutive harvests. Cover crops mulched in situ had similar effects to those of the organic mulches, increasing soil biological activity and reducing B. cinerea primary inoculum and the severity of B. cinerea infection in grapes at harvest (2006). Inter-row phacelia and ryegrass were mulched in winter 2005 and compared with a bare ground control, under 10-year-old Chardonnay vines in a ten-replicate randomized block design. Functional soil biological activity increased by 1.5-4.5 times in the two cover crop treatments compared with the control, an effect possibly related to elevated soil moisture in these treatments. This increase in soil moisture and soil biological activity increased vine debris degradation, reduced B. cinerea primary inoculum on the debris and decreased B. cinerea severity at flowering (December 2005) and harvest (April 2006). These results show the potential of organic mulches and cover crops mulched in situ to enhance soil ecosystem services and improve the sustainability of viticultural practices.
65

Ecological and Chemical Aspects of White Oak Decline and Sudden Oak Death, Two Syndromes Associated With <i>Phytophthora</i> spp

Nagle, Annemarie Margaret January 2009 (has links)
No description available.
66

Optimization of Anaerobic Codigestion Processes of Lignocellulosic Materials of Difficult Degradation with Residues from Andean Livestock

Meneses Quelal, Washington Orlando 19 July 2022 (has links)
Tesis por compendio / [ES] El acceso a fuentes de energía moderna en las áreas rurales de la región andina es uno de los factores principales para disminuir la pobreza ya que su acceso proporcionaría beneficios ambientales, económicos y sociales. Pese a los esfuerzos de buscar fuentes alternativas para subsanar el déficit energético, aún existen millones de personas que sufren la falta de accesibilidad a fuentes de energía moderna, situación que se debe a los altos niveles de pobreza bajo los cuales se encuentran inmersos. Junto a este inconveniente se suma el enorme incremento de residuos agrícolas en las comunidades andinas. Residuos que provienen de las actividades agrícolas, y que podrían ser perjudiciales para el medio ambiente si no se toman medidas adecuadas. Lamentablemente, en muchos países en desarrollo donde se generan grandes cantidades de estos residuos, se sabe poco sobre sus posibles riesgos y beneficios si no se gestionan adecuadamente. Uno de los enfoques más interesantes para abordar esta problemática, es el desarrollo de la gestión sostenible de los residuos orgánicos agrícolas de la región, transformándolos en recursos para la generación de energía renovable (biogás) y fertilizantes orgánicos (digestato). Esta solución permitiría dar una valorización energética a los residuos de la agricultura de la zona, sobre la cual basan su economía, y a la vez contribuiría a una mayor gestión de los residuos evitando el incremento de la contaminación ambiental. Con la finalidad de contribuir al desarrollo energético y mejorar el paradigma de la gestión de residuos en el área andina de Guaranda (Ecuador), la presente Tesis Doctoral aborda la evaluación del potencial bioquímico de metano (BMP) de los residuos orgánicos agrícolas de la región. Se realiza una cuantificación sistemática de la producción de biogás mediante la transformación bioquímica de residuos orgánicos agrícolas, que comprenden: sustratos principales (residuos de estiércol de vicuña, llama y cuy, y residuos de matadero de ganado vacuno) y cosustratos (residuos de paja de amaranto, quinua y trigo). El objetivo general de esta investigación de doctorado se ha llevado a cabo en cuatro fases: (I) Caracterización de la materia prima mediante el análisis elemental y proximal a través de los cuáles se estimó el rendimiento teórico y la biodegradabilidad de los sustratos y cosustratos, (II) Rendimiento de la codigestión de residuos orgánicos agrícolas con mezclas de lodos de aguas residuales en biodigestores batch, (III) Análisis de los efectos sinérgicos y antagónicos durante la monodigestión y codigestión de las materias primas y (IV) Evaluación de la cinética microbiana de la digestión anaerobia mediante los modelos de Gompertz modificado, transferencia, ecuación logística, modelo del cono y Richards modificado. En la caracterización fisicoquímica se determinó que las relaciones SV/ST de los sustratos y cosustratos oscilaron entre 58 y 77% con una relación C/N entre 12 y 102, lo que indicó que estos residuos son materias primas adecuadas para la producción de metano. En todos los ensayos un aumento de la cantidad de inóculo mejoró la biodegradabilidad de los sustratos y por consiguiente la producción metano; así, en la monodigestión se tuvo incrementos de hasta 90% y en la codigestión incrementos del 71%. Todas las mezclas produjeron efectos sinérgicos, donde los mayores porcentajes de metano se dieron cuando las mezclas de residuos de amaranto, quinua y trigo fueron del 50 y 75% de sólidos volátiles. Independientemente de la SIR1:1 y la SIR 1:2 se mejoró la producción de metano de la codigestión al incrementar el porcentaje de cosustrato especialmente de residuos de amaranto y quinua. Los mejores resultados de todos los ensayos realizados se obtuvieron en los biodigestores compuestos por residuos de matadero y residuos de quinua, donde se obtuvieron producciones de metano entre 581 y 555 ml / [CA] L'accés a fonts d'energia moderna en les àrees rurals de la regió andina és un dels factors principals per a disminuir la pobresa ja que el seu accés proporcionaria beneficis ambientals, econòmics i socials. Malgrat els esforços de buscar fonts alternatives per a esmenar el dèficit energètic, encara existeixen milions de persones que pateixen la falta d'accessibilitat a fonts d'energia moderna, situació que es deu als alts nivells de pobresa sota els quals es troben immersos. Al costat d'aquest inconvenient se suma l'enorme increment de residus agrícoles en les comunitats andines. Residus que provenen de les activitats agrícoles, i que podrien ser perjudicials per al medi ambient si no es prenen mesures adequades. Lamentablement, en molts països en desenvolupament on es generen grans quantitats d'aquests residus, se sap poc sobre els seus possibles riscos i beneficis si no es gestionen adequadament. Un dels enfocaments més interessants per a abordar aquesta problemàtica, és el desenvolupament de la gestió sostenible dels residus orgànics agrícoles de la regió, transformant-los en recursos per a la generació d'energia renovable (biogàs) i fertilitzants orgànics (digestato). Aquesta solució permetria donar una valorització energètica als residus de l'agricultura de la zona, sobre la qual basen la seua economia, i alhora contribuiria a una major gestió dels residus evitant l'increment de la contaminació ambiental. Amb la finalitat de contribuir al desenvolupament energètic i millorar el paradigma de la gestió de residus en l'àrea andina de Guaranda (l'Equador), la present Tesi Doctoral aborda l'avaluació del potencial bioquímic de metà (BMP) dels residus orgànics agrícoles de la regió. Es realitza una quantificació sistemàtica de la producció de biogàs mitjançant la transformació bioquímica de residus orgànics agrícoles que comprenen: substrats principals (residus de fem de vicunya, flama i cuy, i residus d'escorxador de bestiar boví), *cosustratos (residus de palla d'amarant, quinua i blat). L'objectiu general d'aquesta investigació de doctorat s'ha dut a terme en quatre fases: (I) caracterització de la matèria primera mitjançant l'anàlisi elemental i proximal a través dels quals es va estimar el rendiment teòric i la biodegradabilitat dels substrats i cosustratos, (II) Rendiment de la codigestión de residus orgànics agrícoles amb mescles de llots d'aigües residuals en biodigestores batch, (III) Anàlisis dels efectes sinèrgics i antagònics durant la monodigestión i codigestión de les matèries primeres i (IV) Avaluació de la cinètica microbiana de la digestió anaeròbia mitjançant els models de Gompertz modificat, transferència, equació logística, model del con i Richards modificat. En la caracterització fisicoquímica es va determinar que les relacions SV/ST dels substrats i cosustratos van oscil·lar entre 58 i 77% amb una relació C/N entre 12 i 102, la qual cosa va indicar que aquests residus són matèries primeres adequades per a la producció de metà. En tots els assajos un augment de la quantitat d'inòcul va millorar la biodegradabilitat dels substrats i per consegüent la producció metà; així, en la monodigestión es va tindre increments de fins a 90% i en la codigestión increments del 71%. Totes les mescles van produir efectes sinèrgics, on els majors percentatges de metà es van donar quan les mescles de residus d'amarant, quinua i blat van ser del 50 i 75% de sòlids volàtils. Independentment de la SIR1:1 i la SIR 1:2 es va millorar la producció de metà de la codigestión en incrementar el percentatge de cosustrato especialment de residus d'amarant i quinua. Els millors resultats de tots els assajos realitzats es van obtindre en els biodigestores compostos per residus d'escorxador i residus de quinua, on es van obtindre produccions de metà entre 581 i 555 ml/g VS. / [EN] Access to modern energy sources in rural areas of the Andean region is one of the main factors to reduce poverty, since its access would provide environmental, economic and social benefits. Despite efforts to find alternative sources to correct the energy deficit, there are still millions of people who suffer from the lack of accessibility to modern energy sources, a situation that is due to the high levels of poverty under which they are immersed. Along with this inconvenience is added the enormous increase in agricultural residues in the Andean communities. Waste that comes from agricultural activities, and that could be harmful to the environment if adequate measures are not taken. Unfortunately, in many developing countries where large amounts of these wastes are generated, little is known about their potential risks and benefits if not managed properly. One of the most interesting approaches to address this problem is the development of sustainable management of agricultural organic waste in the region, transforming it into resources for the generation of renewable energy (biogas) and organic fertilizers (digestate). This solution would allow to give an energetic recovery to the agricultural residues of the area, on which they base their economy, and at the same time would contribute to a better management of the residues avoiding the increase of environmental pollution. To contribute to energy development and improve the paradigm of waste management in the Andean area of Guaranda (Ecuador), this Doctoral Thesis addresses the evaluation of the biochemical potential of methane (BPM) of agricultural organic waste in the region. A systematic quantification of biogas production is carried out through the biochemical transformation of agricultural organic waste that includes main substrates (vicuña, llama and guinea pig manure residues, and cattle slaughterhouse residues) and co-substrates (amaranth straw residues), quinoa and wheat). The general objective of this doctoral research has been carried out in four phases: (I) characterization of the raw material through elemental and proximal analysis through which the theoretical performance and biodegradability of substrates and co-substrates were estimated, (II) Performance of the co-digestion of agricultural organic waste with mixtures of sewage sludge in batch biodigesters, (III) Analysis of synergistic and antagonistic effects during monodigestion and co-digestion of raw materials and (IV) Evaluation of microbial kinetics of anaerobic digestion using modified Gompertz models, transfer, logistic equation, cone model and modified Richards. In the physicochemical characterization it was determined that the VS/TS ratios of the substrates and co-substrates ranged between 58 and 77% with a C/N ratio between 12 and 102, which indicated that these wastes are suitable raw materials to produce methane. In all the tests an increase in the amount of inoculum improved the biodegradability of the substrates and consequently the methane production; thus, in monodigestion there were increases of up to 90% and in co-digestion increases of 71%. All the mixtures produced synergistic effects, where the highest percentages of methane occurred when the mixtures of amaranth, quinoa and wheat residues were 50 and 75% volatile solids. Regardless of SIR1:1 and SIR 1:2, the production of methane from co-digestion was improved by increasing the percentage of co-substrate, especially amaranth and quinoa residues. The best results of all the tests carried out were obtained in the biodigesters composed of slaughterhouse waste and quinoa waste, where methane productions between 581 and 555 ml/g VS were obtained. Regarding the kinetic modelling of the anaerobic digestion process, it was found that all the models fit the experimental values quite well with the predicted ones. In the monodigestion, in all the logistic models, the calculated asymptotes were adjusted very precisely for the specific yield (Me / This work has been carried out within the framework of the project “Analysis of the implementation of biomass exploitation chains in rural communities in the province of Bolívar (Ecuador)” of the ADSIEO-COOPERATION program of the Universitat Politècnica de València (UPV). The Ecuadorian Energy Exploitation Research Network of Biomass (ECUMASA) and the IBEROMASA Network (719RT0586) of the IberoAmerican Program of Science and Technology for Development (CYTED) have participated in this program / Meneses Quelal, WO. (2021). Optimization of Anaerobic Codigestion Processes of Lignocellulosic Materials of Difficult Degradation with Residues from Andean Livestock [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/171722 / Compendio
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Microbial factors associated with the natural suppression of take-all wheat in New Zealand

Chng, Soon Fang January 2009 (has links)
Take-all, caused by the soilborne fungus, Gaeumannomyces graminis var. tritici (Ggt), is an important root disease of wheat that can be reduced by take-all decline (TAD) in successive wheat crops, due to general and/or specific suppression. A study of 112 New Zealand wheat soils in 2003 had shown that Ggt DNA concentrations (analysed using real-time PCR) increased with successive years of wheat crops (1-3 y) and generally reflected take-all severity in subsequent crops. However, some wheat soils with high Ggt DNA concentrations had low take-all, suggesting presence of TAD. This study investigated 26 such soils for presence of TAD and possible suppressive mechanisms, and characterised the microorganisms from wheat roots and rhizosphere using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). A preliminary pot trial of 29 soils (including three from ryegrass fields) amended with 12.5% w/w Ggt inoculum, screened their suppressiveness against take-all in a growth chamber. Results indicated that the inoculum level was too high to detect the differences between soils and that the environmental conditions used were unsuitable. Comparison between the Ggt DNA concentrations of the same soils collected in 2003 and in 2004 (collected for the pot trial), showed that most soils cropped with 2, 3 and 4 y of successive wheat had reduced Ggt DNA concentrations (by 195-2911 pg g-1 soil), and their disease incidences revealed 11 of the 29 test soils with potential take-all suppressiveness. Further pot trials improved the protocols, such that they were able to differentiate the magnitudes of suppressiveness among the soils. The first of the subsequent trials, using 4% w/w Ggt inoculum level, controlled conditions at 16°C, 80% RH with alternate 12 h light/dark conditions, and watering the plants twice weekly to field capacity (FC), screened 13 soils for their suppressiveness against take-all. The 13 soils consisted of 11 from the preliminary trial, one wheat soil that had been cropped with 9 y of wheat (considered likely to be suppressive), and a conducive ryegrass soil. The results revealed that 10 of these soils were suppressive to take-all. However, in only four of them were the effects related to high levels of microbial/biological involvement in the suppression, which were assessed in an experiment that first sterilised the soils. In a repeat trial using five of the soils H1, H3, M2, P7 (previously cropped with 3, 3, 4 and 9 y successive wheat, respectively) and H15 (previously cropped with 5 y of ryegrass), three of them (H1, H3 and M2) had reduced Ggt DNA concentrations (>1000 pg g-1 soil reductions), and were confirmed to be suppressive to take-all. A pot trial, in which 1% of each soil was transferred into a γ-irradiated base soil amended with 0.1% Ggt inoculum, indicated that soils H1 and H3 (3 y wheat) were specific in their suppressiveness, and M2 (4 y wheat) was general in its suppressiveness. The microbial communities within the rhizosphere and roots of plants grown in the soils, which demonstrated conduciveness, specific or general suppressiveness to take-all, were characterised using PCR-DGGE, and identities of the distinguishing microorganisms (which differentiated the soils) identified by sequence analysis. Results showed similar clusters of microorganisms associated with conducive and suppressive soils, both for specific and general suppression. Further excision, re-amplification, cloning and sequencing of the distinguishing bands showed that some actinomycetes (Streptomyces bingchengensis, Terrabacter sp. and Nocardioides sp.), ascomycetes (Fusarium lateritium and Microdochium bolleyi) and an unidentified fungus, were associated with the suppressive soils (specific and general). Others, such as the proteobacteria (Pseudomonas putida and P. fluorescens), an actinomycete (Nocardioides oleivorans), ascomycete (Gibberella zeae), and basidiomycete (Penicillium allii), were unique in the specific suppressiveness. This indicated commonality of some microorganisms in the take-all suppressive soils, with a selected distinguishing group responsible for specific suppressiveness. General suppressiveness was considered to be due to no specific microorganisms, as seen in soil M2. An attempt to induce TAD by growing successive wheat crops in pots of Ggt-infested soils was unsuccessful with no TAD effects shown, possibly due to variable Ggt DNA concentrations in the soils and addition of nutrients during the experiment. Increasing numbers of Pseudomonas fluorescens CFU in the rhizosphere of plants, during successive wheat crops was independent of the Ggt DNA concentrations and disease incidence, suggesting that increases in P. fluorescens numbers were associated with wheat monoculture. This study has demonstrated that TAD in New Zealand was due to both specific and general suppressiveness, and has identified the distinguishing microorganisms associated with the suppression. Since most of these distinguishing microorganisms are known to show antagonistic activities against Ggt or other soilborne pathogens, they are likely to act as antagonists of Ggt in the field. Future work should focus on validating their effects either individually, or interactively, on Ggt in plate and pot assays and under field conditions.
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Produção de ácidos graxos voláteis por fermentação anaeróbia de manipueira e de permeado de soro de queijo / Production of volatile fatty acids by anaerobic fermentation of manipueira and cheese whey permeate

Zempulski, Denise Aparecida 22 February 2013 (has links)
Made available in DSpace on 2017-07-10T18:08:21Z (GMT). No. of bitstreams: 1 Denise A Zempulski.pdf: 2130382 bytes, checksum: 374994e9876ab99db94941e030ce4a28 (MD5) Previous issue date: 2013-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cassava is a crop widely throughout the national territory. In 2011, the national production of cassava was estimated at 27.1 million tons, achieving an increase of 9.2% compared to the 2010 harvest. Among the liquid waste processing cassava, cites the Manipueira, it is the water content of the root mass extracted in pressing grated, in making flour. Manipueira residue is more problematic, because it has high pollution load and toxic potential due to the presence of cyanogenic glycosides, may cause serious problems to the environment and aquatic life if released into waterways. Other big environmental waste when discarded improperly, are waste dairy industries. The fractionation of milk constituents by ultrafiltration results in derivatives with great nutritional value and commercial, such as the retentate (concentrate fraction composed of protein and fat) and permeates (fraction diluted comprising lactose, minerals, electrolytes, nitrogen and water). Recently there is a higher quest for use of agro-industrial waste in order to recover substances and/or materials and thus increase economic efficiency of production processes. The application of agro-industrial residues in bioprocesses is used like alternative substrate, and a help to solve the problem of pollution in the processes of industrialization, where anaerobic digestion stands out due to its many favorable characteristics. One way to minimize environmental impacts and add value to the effluent is its use in the production of volatile fatty acids (VFA) production via anaerobic fermentation, which is the main objective of this work. All fermentations were performed at 30 ° C and 80 rpm with pig inoculum. Initially made up four fermentations, changing the substrate used (cassava, starchy hydrolyzate, whey permeate and synthetic medium) where obtained better results of VFA concentrations with cheese whey permeated and Manipueira. So, with these two substrates, was done the test without light (dark fermentation), and this new detail was responsible to increase the production of VFA in 38% for the manipueira and 20% for the permeate. Following an experimental design 22 was carried out with in quadruplicate central point for Manipueira, where they were tested three levels of glucose concentration (9, 19 e 29 g.L-1) and sodium bicarbonate (0.21, 1.71 and 3.21 g.L-1), and glucose concentrations of 29 g.L-1 and bicarbonate 3.21 g.L-1 that resulted in the increased production of VFA (1941,4 mg L-1 in 23 h) representing an increase of 77,3% in production. For the cheese whey permeate also was done test changing the glucose (75, 45 e 25 g.L-1) and alkalinity (7,7, 8,14, 9,2, 10,26 e 10,7 g.L-1). The best levels founded in this work for the permeate are 45 g.L-1 of glucose and 10,26 g.L-1 of alkalinity, resulting in 4115,16 mg.L-1 of VFA in 41 h. / A mandioca é uma cultura amplamente difundida por todo o território nacional. Em 2011, a produção nacional de mandioca foi estimada em 27,1 milhões de toneladas, obtendo uma variação positiva de 9,2% em relação à safra de 2010. Entre os resíduos líquidos do processamento da mandioca, cita-se a manipueira, que caracteriza a água de constituição da raiz, extraída na prensagem da massa ralada, na confecção da farinha. A manipueira é o resíduo mais problemático, por possuir elevada carga poluente e potencial tóxico devido à presença de glicosídeos cianogênicos, podendo causar sérios problemas ao meio ambiente e à vida aquática quando descartada inadequadamente. Outros resíduos de grande impacto ambiental quando descartados incorretamente, são os resíduos de indústrias de laticínio. O fracionamento dos constituintes do leite por ultrafiltração resulta em derivados de grande valor nutricional e comercial, como o retentado (fração concentrada composta por proteínas e gordura) e o permeado (fração diluída composta por lactose, sais minerais, eletrólitos, compostos nitrogenados e água). Recentemente há uma maior busca pelo uso de resíduos agroindustriais visando recuperar substâncias e/ou materiais e deste modo aumentar a eficiência econômica dos processos de produção. A aplicação de resíduos agroindustriais em bioprocessos é uma alternativa observada na forma de substratos, e uma ajuda para solucionar o problema da poluição nos processos de agroindustrialização, onde a digestão anaeróbia destaca-se devido as suas diversas características favoráveis. Uma das maneiras de minimizar os impactos ambientais e agregar valor ao efluente é a sua utilização na produção de ácidos graxos voláteis (AGVs) via fermentação anaeróbia, sendo este o objetivo principal deste trabalho. Todas as fermentações foram realizadas a 30ºC e 80 rpm com inoculo suíno. Inicialmente fez-se 4 fermentações, variando o substrato utilizado (manipueira, hidrolisado amiláceo, permeado de soro de queijo e meio sintético) onde obteve-se maiores resultados de concentração de AGVs com a manipueira e o permeado. Seguiram-se os estudos com estes dois substratos, fazendo-se o teste de ausência de luminosidade (fermentação escura), sendo esta estratégia responsável pelo aumento de 38% na produção de AGVs para a manipueira e 20% para o permeado. A seguir foi realizado um planejamento experimental 22 com quadruplicata no ponto central para a manipueira, onde foram testados 3 níveis de concentração de glicose (9, 19 e 29 g.L-1) e bicarbonato de sódio (0,21, 1,51 e 3,21 g.L-1), sendo as concentrações de glicose de 29 g.L-1 e bicarbonato de 3,21 g.L-1 as que resultaram em maior produção de AGV (1941,4 mg.L-1 em 23 h) representando um acréscimo de 77,3% na produção. Para o permeado de soro de queijo também foram realizados testes variando níveis de glicose (75, 45 e 25 g.L-1) e alcalinidade do meio (7,7, 8,14, 9,2, 10,26 e 10,7 g.L-1). Os níveis que apresentaram melhor resultado foram 45 g.L-1 de glicose e 10,26 g.L-1 de alcalinidade, resultando em 4115,16 mg.L-1 de AGVs em 41h.
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Studi sulle dinamiche dell'inoculo di Guignardia bidwellii, agente causale del marciume nero della vite / STUDIES ON INOCULUM DYNAMICS OF Guignardia bidwellii, CASUAL AGENT OF GRAPE BLACK-ROT / Studies on inoculum dynamics of Guignardia bidwellii, causal agent of grape black-rot

ONESTI, GIOVANNI 17 March 2016 (has links)
L’ascomicete Guignardia bidwellii, agente causale del marciume nero della vite, è un patogeno economicamente importante in alcuni areali viticoli. La conoscenza, disponibile sul marciume nero dell’uva, è stata recuperata dalla letteratura, analizzata e sintetizzata per sviluppare un modello meccanicistico del ciclo di vita del patogeno, guidata dalle variabili meteorologiche e dalla fenologia della vite, e basata sull'analisi dei sistemi. Il modello è stato poi valutato per la sua capacità di rappresentare il sistema reale e la sua utilità per la comprensione di epidemie di marciume nero su foglie e grappoli in un vigneto del Nord Italia, nel 2013 al 2015. Successivamente, le mancanze di conoscenza sono state analizzate, studiate e quindi colmate attraverso specifici esperimenti. In un primo passo, le dinamiche dell’inoculo primario e dei modelli di dispersione (di entrambi ascospore e conidi) da mummie svernate sono state studiate in un vigneto sperimentale per tre anni. In un secondo passo, l'effetto della temperatura e dell'umidità sulla formazione di picnidi di G. bidwellii e la successiva estrusione di cirri, nelle lesioni su foglia, la produzione e la germinazione dei conidi (inoculo secondario), e la lunghezza del periodo di latenza sono stati studiati sia in condizioni di campo che in ambiente controllato. In un terzo passo, sono stati condotti studi in ambiente controllato per studiare la produzione di conidi di G. bidwellii sulle lesioni di foglie, influenzata da lavaggi ripetuti e alternando periodi di secco ed umido. Il modello epidemiologico sviluppato in questa tesi può essere utilizzata da viticoltori come strumento predittivo per la pianificazione di trattamenti fungicidi nei vigneti. / The ascomycete Guignardia bidwellii, causal agent of black-rot on grapevines, is an economically important pathogen in some viticultural areas. The available knowledge on black-rot of grape was retrieved from literature, analyzed, and synthesized to develop a mechanistic model of the life cycle of the pathogen, driven by weather and vine phenology, and based on the systems analysis. The model was then evaluated for its ability to represent the real system and its usefulness for understanding black-rot epidemics on leaves and bunches in a vineyard of north Italy, in 2013 to 2015. Thereafter, weaknesses in our knowledge were analysed and studied through specific experiments. In a first step, dynamics of primary inoculum and dispersal patterns (both ascospores and conidia) from overwintered grape mummies were investigated in an experimental vineyard during three years. In a second step, the effect of temperature and humidity on the formation of G. bidwellii pycnidia and the extrusion of cirri in grape leaf lesions, production and germination of conidia (secondary inoculum), and the length of the latency period were studied under both environmental and controlled conditions. In a third step, environmental-controlled studies were conducted to investigate the production course of G. bidwellii conidia on grape leaf lesions as influenced by repeated washing events and alternate dry and wet periods. The model developed in this thesis can be used by vinegrowers as a predictive tool for scheduling fungicide sprays in the vineyards.

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