Universiẗat, Diss., 2002--Jena.

Orientador: Katia Cristina Kupper / Banca: Ben-Hur Mattiuz / Banca: Sérgio Florentino Pascholati / Resumo: Dentre as principais doenças que ocorrem na pós-colheita em citros destacam-se o bolor verde, bolor azul e a podridão azeda, ocasionadas pelos fungos Penicillium digitatum, P. italicum e Geotrichum candidum, respectivamente. Uma alternativa para o controle destas doenças se dá por meio da utilização de leveduras. Sendo assim, objetivou-se no presente estudo isolar, selecionar e identificar leveduras de solos, folhas, flores e frutos de citros de diferentes regiões produtoras do estado de São Paulo, com potencial de aplicação como agentes de biocontrole aos fitopatógenos de pós-colheita. Foram obtidos 95 isolados de leveduras de 14 municípios do estado de São Paulo, sendo o filoplano a fonte de 90,5% dos isolados. Nos ensaios in vitro realizados com G. candidum, o ACBL-77 proporcionou o maior valor de inibição do crescimento micelial do fungo (35%) e os isolados ACBL-68 e ACB-K1 (Saccharomyces cerevisiae), os que proporcionaram maiores valores de inibições na germinação de conídios, 83 e 82%, respectivamente. Quando se avaliou o controle da podridão azeda em frutos de Laranja Pêra, três isolados (ACBL-23, ACBL-44 e ACBL-77) foram os mais eficientes no controle da doença de maneira preventiva e curativa. Em ensaios realizados in vitro com P. digitatum, cinco isolados de levedura (ACBL-76, ACBL-82, ACBL-84 e ACBL-87) proporcionaram valores de inibições do crescimento da colônia do fungo acima de 80%. Entretanto, in vivo somente dois isolados (ACBL-82 e ACBL-86) foram capazes de controlar o progresso e também a incidência da doença, quando utilizados preventivamente. Na avaliação da inibição do crescimento micelial in vitro do P. italicum, oito isolados proporcionam valores de inibições acima de 80%, sendo que o ACBL-04 proporcionou 100% de controle. Nos ensaios in vivo, quatro isolados (ACBL-04, ACBL-05, ACBL-08 e ACBL-11) foram eficientes na diminuição ... / Abstract: Among the major diseases that occur in citrus post-harvest stand out green mold, blue mold and sour rot, caused by Penicillium digitatum, Penicillium italicum and Geotrichum candidum, respectively. An alternative for the control of these diseases is through the use of yeasts. Thus, the aim of the present study was to isolate, select and identify yeasts from soil, leaves, flowers and fruits of different citrus producing regions of the São Paulo State, with potential application as biocontrol agents for postharvest pathogens. Ninety-five yeast isolates were obtained from 14 counties in the São Paulo State. The phylloplane was the source of 90.5% of the isolates. Tests conducted in vitro, with G. candidum showed that ACBL-77 presented the highest inhibition of mycelial growth (35%) and both strains ACBL-68 and ACB-K1 (Saccharomyces cerevisiae), provided the highest values of inhibitions of conidia germination, 83 and 82%, respectively. When the control of sour rot in fruits of 'Pera' sweet Orange was evaluated, three isolates (ACBL-23, ACBL-44 and ACBL-77) were the most effective in controlling the disease in a preventive and curative way. In in vitro assays with P. digitatum, five yeast strains (ACBL-76, ACBL-82, ACBL-84 and ACBL-87) inhibited the mycelial growth with values above 80%. However, when the ability of yeast to control green mold was evaluated on orange fruits, only two isolates (ACBL-82 and ACBL-86) were able to decrease the progress and also the incidence of the disease when used preventively. Eight isolates inhibited the mycelial growth of P. italicum above 80%, and the isolate ACBL-04 provided 100% of inhibition. In in vivo assays, four isolates (ACBL-04, ACBL-05, ACBL-08 and ACBL-11) were effective in reducing the progress of blue mold as well as in inhibiting the incidence of disease when applied preventively / Mestre

Computational tools play an important role in the description of biological systems. Scientists describe and study structure, conformational changes and interactions between molecules in silico, often as a cheaper and faster alternative for biosynthesis. The simulated dynamic behavior in time of a molecular system is a straight forward source of information about substrate-enzyme interactions at the atomic level, and a powerful tool for the identification of molecular properties important in enzymatic reactions. Our study is focused on the computational investigation of structure and substrate specificity of hydrolases important in biotransformation. The computational work was performed in close collaboration with biochemists-experimentalists from Charles University and the Microbiological Institute of the Academy of Sciences of the Czech Republic. Hydrolases have great a potential in the chemoenzymatic synthesis of modified carbohydrates with regulated properties. Carbohydrates, as substrates of hydrolases, are important in normal functionality of many organisms. They have a dual role in immune response regulation: some carbohydrates (like GlcNAc and ManNAc) participate in activation and some (like GalNAc) in suppressing immunity; glycosidase deficiency is associated with a number of lysosomal disorders. We used homology modeling, computational docking and molecular dynamics simulation (MD) methods for the complex study of fungal hydrolases: alpha-galactosidase/alpha-N-acetylgalactosaminidase from Aspergillus niger; beta-N-acetylhexosaminidases (HEX) (from Aspergillus oryzae and Penicillium oxalicum); nitrilase from Aspergillus niger. Our structural study unambigously demonstrates that the enzyme encoded by genes variant A (aglA) from A. niger is able to accept alpha-N-acetylgalactosamine as its substrate and explains structural features responsible for its specificity. Homology models of HEXs from P. oxalicum and A. oryzae were built and compared. Homology models were used to study the role of protein glycosylation, disulfide bonds, dimer formation and interaction with natural and modified substrates. Model of nitrilase from Aspergillus niger helped to analyze multimer formation.

New drugs, particularly antibiotics, are urgently required to combat the increasing problem of antibiotic resistant human pathogens. Due to the scarcity of products available today, the pharmaceutical industry is now under pressure to reassess compounds derived from plants, soil and marine organisms. Pharmaceutical companies are showing renewed interest in marine biotechnology as the oceans represent a rich source of both biological and chemical diversity of novel molecular structures with anti-cancer, anti-inflammatory and antibiotic properties. Formerly unexplored locations, such as deep ocean sediments, show great potential as a source of genetically novel microorganisms producing structurally unique secondary metabolites. In this research, a metabolite producing marine Pseudoalteromonas strain, known as AP5, was initially used to develop methods for the detection, optimisation of production and extraction of bioactive metabolites from other potentially novel marine isolates. Two hundred and seventy six (276) marine isolates from water and sediment samples from the Antarctic Ocean and Marion Island were isolated. Ten visually different isolates were screened for bioactivity against Gram-positive and -negative bacteria, fungi and yeast. Three out of the 10 isolates, WL61 , WL 114 and WL 136, appeared to be novel Streptomyces spp. showing activity against different test organisms. Many of these marine microorganisms are difficult to culture in the laboratory, particularly when they are cultivated continuously in shake flasks as they can stop producing bioactive compounds. The cultivation of marine isolates in bioreactors may be a more beneficial process for the optimisation of metabolite production compared to conventional liquid fermentation techniques whereby the solid-liquid-air interface of membrane bioreactors can imitate the natural environment of microbes. The membrane bioreactor system is a stable growth environment with low shear that supports steady-state biofilm growth consisting of a high cell density due to a high mass transfer of nutrients and oxygen to the cells. This approach was employed and isolates WL61, WL114 and WL136 were immobilised onto ceramic membranes using Quorus single fibre bioreactors (SFR). The SFRs were used to establish the most suitable growth medium for continuous secondary metabolite production. The best growth conditions were applied to the Quorus multifibre bioreactor (MFR) for scale up of biologically active metabolites, highlighting the potential of bioreactor technology for use in bioprospecting for isolating and screening novel and known organisms for new and interesting natural products. Furthermore, the Quorus MFR was shown to be suitable for the production of high yields of antimicrobial metabolites and is an efficient new fermentation production system. Purification by HPLC fractionation was used to characterise four major compounds from isolate WL 114 extracts. NMR structure elucidation identified one of the two primary compounds as Bisphenol A. The complete chemical structure for the second potent bioactive compound could not be determined due to the low concentration and volume of material. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

Made available in DSpace on 2016-06-02T20:34:09Z (GMT). No. of bitstreams: 1 1945.pdf: 15081924 bytes, checksum: 00974965287616958596ef07bc4deaa4 (MD5) Previous issue date: 2007-06-29 / Nowadays, the microorganisms are responsible for the production of several antibiotics, immunosuppressant and antitumors, furthermore they are extremely important in industrial process. This work describes the production process and the isolation of the citrinin (234,6 mg/L) and of the mycophenolic acid (371,2 mg/L) with high purity levels in the process of extraction of a fermentation of 8 and 12 days respectively of a cultivation in liquid in Czapek medium enriched with 0,2% of extract of yeast utilizing the fungi Penicillium Catl1.1 and Penicillium sp. Casp5, isolated of the Coffea arabica L. after asepsis, as well, the development of an analytical methodology to quantify this compounds using the NMR. Additionally, on this work, we describe the isolation and the structural elucidation of an new alkaloid from prodiginine class with modification on ring (C), from an extract produced by Streptomyces violaceusniger violaceusniger actinomycete, isolated as an endophyte from Zea mays L. leaves and identified by Costa (2005), which was able to inhibit the growing of phytopatogens with economic value (Pythium aphanidermatum, Rhizoctonia solani, Sclerotinia sclerotiorum, Phytophthora parasitica e Fusarium moniliforme). Therefore, Finally, due to the results obtained during the execution of this work, is able to conclude that the Nuclear Magnetic Resonance, beyond be presented like an efficient analytic technique in the quantification of the citrinin and of the mycophenolic acid in the extract fungi, was fundamental in the monitoring and optimization of the conditions of extraction during the period of 20 days of fermentation. Like this, to NMR is a technique that will be utilized in the process production and optimization of the substances produced by microorganisms in industrial scale. / Atualmente, os microrganismos são responsáveis pela produção de vários antibióticos, imunossupressores e anti-tumorais, além de serem importantíssimos em processos industriais. O presente trabalho descreve os processos de produção e isolamento da citrinina (234,6 mg/L) e do ácido micofenólico (371,2 mg/L) com alto grau de pureza no processo de extração de uma fermentação de 8 e 12 dias respectivamente de um cultivo em meio líquido Czapek enriquecido com 0,2 % de extrato de levedura utilizando os fungos Penicillium Catl1.1 e Penicillium sp. Casp5, isolados do Coffea arabica L. após assepsia, bem como, o desenvolvimento de uma metodologia de quantificação por RMN. Adicionalmente, neste trabalho foi feito o isolamento e a elucidação de um alcalóide inédito da classe das prodigininas (antibiótico oligopirrol-pigmentado) com modificação no anel C, a partir de um extrato produzido pela actinobactéria Streptomyces violaceusniger violaceusniger, isolado como endofítica de folhas de milho (Zea mays L.) e identificado por Costa (2005). Este antibiótico foi capaz de inibir o crescimento de fitopatógenos de interesse econômico tais como: Pythium aphanidermatum, Rhizoctonia solani, Sclerotinia sclerotiorum, Phytophthora parasitica e Fusarium moniliforme. Portanto, através dos resultados obtidos durante a execução deste trabalho, pode-se concluir que a Ressonância Magnética Nuclear, além de se apresentar como uma técnica analítica eficiente na quantificação da citrinina e do ácido micofenólico no extrato fúngico, foi fundamental no monitoramento e otimização das condições de extração durante o período de 20 dias de fermentação. Assim, a RMN é uma técnica que poderá ser utilizada na otimização de processos de produção de substâncias produzidas por microorganismos em escala industrial.

Made available in DSpace on 2016-06-02T20:34:51Z (GMT). No. of bitstreams: 1 Retido.pdf: 19733 bytes, checksum: 6aad255badc436a06364517de2344ab6 (MD5) Previous issue date: 2014-03-31 / Universidade Federal de Minas Gerais / The project "Metabolic, enzymatic and genetic studies of the endophytic fungus P. brasilianum" resulted in biosynthetic studies of bisphenylpropanoid amides, the brasilimides, confirming the origin of these substances via phenylpropanoid biosynthesis pathway, very unusual in fungi. PAL activity, the first enzyme involved in this biosynthetic route was successfully evaluated and the conditions of PAL production by P. brasilianum were optimized (culture medium and induction of PAL adding Phe to the culture), and the incubation conditions of the enzymatic reaction. The specificity of the PAL enzyme was studied, and the enzyme showed activity toward all substrates tested, including acting as TAL (tyrosine ammonia lyase). In vivo studies throught the addition of different substrates lead to N-acetylation confirmed by spectroscopy data. The genome of the fungus P. brasilianum was sequenced, and extensive studies through bioinformatics lead to the gene encoding PAL enzyme. From molecular biology studies, the enzyme was cloned and expressed as recombinant PAL fused to a SUMO protein and a his-tag at the N- terminus of the protein in pETSUMO vector expressed in E. coli BL21 (DE3) to obtain the best conditions for enzyme overexpression in its soluble form. The purification process of the recombinant enzyme was studied from a single purification step (affinity chromatography) by pH gradient elution, obtaining a high degree of purity confirmed by one-dimensional electrophoresis. The pure recombinant PAL enzyme obtained was characterized by MS and biochemically yielding Km values of 4,8 mM. Recent studies seem to point out that there is a relationship between the production of brasiliamides when the fungus is subjected to stress conditions. The PAL enzyme appears to be involved in defense mechanisms in this fungus, as has been described for plants. / O projeto "Estudos metabólicos, enzimáticos e genéticos do fungo endofítico P. brasilianum" tratou de investigações biossintéticas das amidas bisfenilpropanoídicas, as brasiliamidas, confirmando a origem fenilpropanoídica destas substâncias, muito incomum em fungos. A atividade da enzima Fenilalanina amônia-liase, primeira da rota biossintética, foi avaliada pela primeira vez no fungo em estudo, e as condições da produção de PAL por P. brasilianum foram otimizadas (meio de cultivo e indução ao adicionar fenilalanina ao cultivo), assim como as condições de incubação da reação enzimática. A especificidade da enzima foi determinada a qual se apresentou altamente promíscua em todos os substratos testados, inclusive atuando como TAL (tirosina amônia-liase). In vivo, a adição de diferentes precursores ao meio de cultivo levou a N-acetilação destes confirmado por dados espectroscópicos. O genoma do fungo P. brasilianum foi sequenciado, e através de extensos estudos de bioinformática pode-se determinar o gene que codifica a enzima PAL. A partir de estudos de biologia molecular foi possível clonar e expressar a enzima PAL recombinante fusionada a uma proteína SUMO e uma cauda polihis no N-terminal da proteína em vetor pETSUMO expresso em E. coli BL21(DE3) obtendo-se, dessa maneira, as melhores condições para superexpressão enzimática na forma solúvel. O processo de purificação da enzima recombinante foi estudado a partir de um único passo de purificação (coluna de afinidade) por gradiente de pH, obtendo alto grau de pureza comprovado através de eletroforese monodimensional. A enzima PAL recombinante pura obtida foi caracterizada por MS e bioquimicamente obtendose valores de Km de 4,8 mM. Estudos parecem deixar claro que exista uma relação entre a produção de brasiliamida A quando o fungo é submetido a situações de estresse, seguindo mesmo comportamento relatado em plantas e, portanto, a enzima PAL parece estar envolvida em mecanismos de defesa neste fungo.

Made available in DSpace on 2016-06-02T20:36:55Z (GMT). No. of bitstreams: 1 6548.pdf: 4383232 bytes, checksum: 8fc19ea524835c26efc13265b5ea37ad (MD5) Previous issue date: 2014-03-27 / Financiadora de Estudos e Projetos / Endophytic microorganisms have a great enzymatic potential to biotransformate substances of natural and synthetic origin due to strategies developed during colonization to coexist with the plant in an initial hostile environment. Microbial transformation of Diels-Alder cycloadducts were trailed by the endophyte P. brasilianum using intact cells and resulted in the production of several products (17). These products were identified as products of chlorination (Q4_F2_15), epoxidation (Q1A_CR_16, Q2A_CR_6, Q3A_CR_5), epoxidation and reduction of conjugated double bond (Q2A_CR_5), reduction of conjugated double bond (Q2A_CR_9, Q3A_CR_7_pico2, Q3A_CR_8, Q4A_CR_23), reduction of isolated double bond (Q1A_CR_26), oxidation of allilic methyl group and reduction of conjugated double bond (Q4A_CR_10), reduction of carbonyl and conjugated double bond (Q4A_CR_20), reduction of carbonyl and ether formation (Q5A_CR_15) and finally, reduction of carbonyl group (Q4A_CR_15 e Q5A_CR_18). The reduction of conjugated double bond can be performed by enzymes called Old Yellow Enzymes (OYE), also known as enoate reductase enzymes. The products of carbonilic or double bond reduction were also synthesized chemically and the enantioselectivity of both in vitro and in vivo process were compared. In all cases, microbiological transformations were more enantioselectivity. / Devido às estratégias usadas para a colonização do hospedeiro e à convivência com a planta em um ambiente inicialmente hostil, os micro-organismos endofíticos possuem um grande potencial enzimático para biotransformar substâncias de origem natural e seus análogos sintéticos. A transformação dos cicloadutos de Diels-Alder feitas pelo endofítico P. brasilianum utilizando-se células intactas resultou na produção de 17 produtos de biotransformação. Esses produtos foram identificados como sendo produtos de halogenação (Q4_F2_15), epoxidação (Q1A_CR_16, Q2A_CR_6, Q3A_CR_5), epoxidação e redução da olefina conjugada (Q2A_CR_5), redução da dupla ligação α, β- insaturada (Q2A_CR_9, Q3A_CR_7_pico2, Q3A_CR_8, Q4A_CR_23), redução da olefina isolada (Q1A_CR_26), oxidação alílica de metila e redução da dupla conjugada (Q4A_CR_10), redução carbonílica e dupla conjugada (Q4A_CR_20), redução carbonílica e formação de éter (Q5A_CR_15) e redução de grupos carbonílicos (Q4A_CR_15 e Q5A_CR_18). As reduções das olefinas pertencentes ao sistema α, β- insaturada podem ter sido catalisadas por enzimas da família Old Yellow Enzymes (OYE), também conhecidas por enoato redutases. Os produtos de redução C=C do sistema α, β- insaturado e redução carbonílica também foram sintetizados quimicamente e a enantiosseletividade de ambos os processos foram comparadas. Em todos os casos, as transformações microbiológicas apresentaram uma maior enantiosseletividade.

Made available in DSpace on 2014-11-10T11:09:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-21Bitstream added on 2014-11-10T11:57:41Z : No. of bitstreams: 1 000792114.pdf: 1360577 bytes, checksum: e30201b234dbc8d6d40a9a749ab8571e (MD5) / Dada à importância econômica e social que a citricultura representa para o país, e em particular, para o estado de São Paulo, as plantas cítricas podem ser afetadas por vários agentes fitopatogênicos que, agindo isoladamente, ou em conjunto, sob condições favoráveis, podem tornar-se limitantes à produção em várias regiões produtoras. Dentre tais agentes fitopatogênicos destacam-se Geotrichum candidum, Penicillium digitatum e P. italicum, responsáveis pelas doenças podridão azeda, bolor verde e bolor azul, respectivamente, que ocorrem na pós-colheita em citros. O método mais efetivo de controle destas doenças é o químico, porém, alternativas de controle são necessárias, de forma a diminuir os riscos ambientais e à saúde humana, em decorrência do uso indiscriminado de fungicidas. Dentre os métodos alternativos, o controle biológico tem emergido como um dos mais promissores para controle de doenças na pós-colheita. Diante do exposto, o presente trabalho teve como objetivo avaliar os mecanismos de ação de 24 isolados de leveduras que apresentam potencialidade de controle da podridão azeda e de bolores em frutos cítricos. Nosso estudo sugere que os múltiplos modos de ação, como apresentado pela maioria dos isolados de leveduras testados, como produção de enzimas hidrolíticas (quitinase e β-1,3-glucanase), atividade killer e inibição da germinação de conídios do fitopatógeno, foram importantes para o potencial de controle de Geotrichum candidum, Penicillium digitatum e P. italicum. Todos os isolados de leveduras apresentaram atividade killer, indicando ser esse o mecanismo de ação comum adotado pelos isolados no biocontrole / Because of the economic and social importance that citrus industry represent to the country, and in particular to the state of São Paulo, citrus plants can be affected by several pathogenic agents , acting alone or together , under favorable conditions may make limiting the production in some production areas. Among these pathogenic agents have more importance Penicillium digitatum, Penicillium italicum and Geotrichum candidum, responsible for diseases that occuring in the post - harvest citrus. The most effective method of controlling these diseases is by means of chemical control, but control alternatives are needed in order to reduce environmental and human health risks due to the indiscriminate use of fungicides. Among the alternative methods, biological control has emerged as one of the most promising for disease control. So the present study was to evaluate the mechanisms of action of 24 yeast isolates that have potential for control of sour rot and mold in citrus fruits. Our study suggests that multiple modes of action, as shown by the majority of yeast isolates tested, which showed production of hydrolytic enzymes (chitinase and β-1,3-glucanase), killer activity and inhibition of conidial germination of the pathogen were important for the potential control of Geotrichum candidum, Penicillium digitatum and P. italicum. All yeast isolates showed killer activity, indicating that this is the common mechanism adopted by the biocontrol isolates

Memoria para optar al Título Profesional de Ingeniero Agrónomo / El control de enfermedades de poscosecha es una problemática constante en la producción de uva de mesa, siendo Botrytis cinerea y Penicillium expansum, dos de los patógenos más importantes. El cuestionamiento a la cantidad máxima de residuos de agroquímicos permitidos en la fruta en los mercados de destino y la acotada cantidad de fungicidas disponibles en el mercado, han llevado a la búsqueda de alternativas a los fungicidas sintéticos, la cual se ha enfocado a productos naturales, amigables con el medio ambiente y libres de residuos. El principal objetivo de este estudio fue evaluar la actividad de 15 extractos de macrohongos en el control de ambos patógenos. Los macrohongos fueron colectados desde su ambiente natural, posteriormente secados, triturados y macerados en alcohol al 95%, y los extractos resultantes fueron utilizados en bioensayos de inhibición in vitro e in vivo. Para el control in vitro se enmendó agar papa dextrosa con cada extracto en etanol al 1% donde se sembró micelio y conidias de los patógenos. El control in vivo se realizó sobre bayas de uva de mesa del cv. Red Globe sometidas o no a desinfección previa con NaClO (0,5%). A las bayas se les realizó una herida y luego se aplicaron los extractos 1 y 24 horas antes de la inoculación con conidias de los patógenos. Los extractos con mayor efectividad inhibitoria in vitro del crecimiento miceliar de B. cinerea fueron Suillus luteus, Agarical sp. y Amanita sp. los que inhibieron en un 92,9, 71,0 y 69,4%, respectivamente. Para el control in vitro de P. expansum los dos extractos que tuvieron un mayor efecto fueron los de Agarical sp. y Agaricus arvensis con un 35,3 y 34,6% de inhibición del crecimiento miceliar, respectivamente. Los extractos con mayor efectividad en la inhibición de la germinación de conidias fueron: Agarical sp. y Macrolepiota rhacodes, para B. cinerea, y Agaricus arvensis y Laetiporus sulphureus para P. expansum. En el control in vivo solo el extracto de Amanita sp. tuvo un efecto en la inhibición de la pudrición causada por B. cinerea sobre las bayas, aplicado 24 horas antes de la inoculación, e igualmente en bayas sin desinfectar inoculadas con P. expansum. / Postharvest rots of table grapes are a constant problem for the industry with Botrytis cinerea and Penicillium expansum as the most important pathogens. Restrictions on the maximum amount of pesticide residues allowed on the fruit, and the limited number of fungicides registered in the markets have prompted the look for alternatives to the traditional chemical fungicides, focusing mainly on natural products environmentally friendly and free from residue restrictions. This study was aimed to evaluate the activity of 15 extracts of mushrooms in the control of both pathogens. The mushrooms were collected from their natural sources, dried, grounded and macerated in ethanol 95%, and the extracts obtained were evaluated in vitro and in vivo. Potato dextrose agar media was amended with the ethanol extracts at a rate of 1%, for the in vitro tests with mycelia or conidia of the pathogens. In vivo assays were conducted on Red Globe berries that were surface disinfected with NaOCl (0,5 %) or not disinfected at all. The berries were wound inoculated with a spore suspension of each pathogen 1 or 24 hours after the extracts treatments. The extracts that gave the greatest inhibition of the mycelial growth of B. cinerea were those of Suillus luteus, Agarical sp. and Amanita sp, which gave a 92.9, 71.0 and 69.4 % inhibition, respectively. While the extracts with the higher inhibition of the mycelial growth of P. expansum were those of Agarical sp. and Agaricus arvensis with 35.3 and 34.6 % inhibition, respectively. The extracts with the higher inhibition of the conidia germination were those of Agarical sp. and Macrolepiota rhacodes, for B. cinerea, and Agaricus arvensis and Laetiporus sulphureus for P. expansum. Only the extract of Amanita sp. reduced the rot caused by B. cinerea when applied 24 hours before berry inoculation and the rot caused by P. expansum on berries that were not disinfected.

Made available in DSpace on 2014-06-11T19:27:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-12-06Bitstream added on 2014-06-13T19:55:56Z : No. of bitstreams: 1 000749700.pdf: 3868289 bytes, checksum: 9b3635588bdc5371eddfe626ebc297d8 (MD5) / Dentre as principais doenças que ocorrem na pós-colheita em citros destacam-se o bolor verde, bolor azul e a podridão azeda, ocasionadas pelos fungos Penicillium digitatum, P. italicum e Geotrichum candidum, respectivamente. Uma alternativa para o controle destas doenças se dá por meio da utilização de leveduras. Sendo assim, objetivou-se no presente estudo isolar, selecionar e identificar leveduras de solos, folhas, flores e frutos de citros de diferentes regiões produtoras do estado de São Paulo, com potencial de aplicação como agentes de biocontrole aos fitopatógenos de pós-colheita. Foram obtidos 95 isolados de leveduras de 14 municípios do estado de São Paulo, sendo o filoplano a fonte de 90,5% dos isolados. Nos ensaios in vitro realizados com G. candidum, o ACBL-77 proporcionou o maior valor de inibição do crescimento micelial do fungo (35%) e os isolados ACBL-68 e ACB-K1 (Saccharomyces cerevisiae), os que proporcionaram maiores valores de inibições na germinação de conídios, 83 e 82%, respectivamente. Quando se avaliou o controle da podridão azeda em frutos de Laranja Pêra, três isolados (ACBL-23, ACBL-44 e ACBL-77) foram os mais eficientes no controle da doença de maneira preventiva e curativa. Em ensaios realizados in vitro com P. digitatum, cinco isolados de levedura (ACBL-76, ACBL-82, ACBL-84 e ACBL-87) proporcionaram valores de inibições do crescimento da colônia do fungo acima de 80%. Entretanto, in vivo somente dois isolados (ACBL-82 e ACBL-86) foram capazes de controlar o progresso e também a incidência da doença, quando utilizados preventivamente. Na avaliação da inibição do crescimento micelial in vitro do P. italicum, oito isolados proporcionam valores de inibições acima de 80%, sendo que o ACBL-04 proporcionou 100% de controle. Nos ensaios in vivo, quatro isolados (ACBL-04, ACBL-05, ACBL-08 e ACBL-11) foram eficientes na diminuição... / Among the major diseases that occur in citrus post-harvest stand out green mold, blue mold and sour rot, caused by Penicillium digitatum, Penicillium italicum and Geotrichum candidum, respectively. An alternative for the control of these diseases is through the use of yeasts. Thus, the aim of the present study was to isolate, select and identify yeasts from soil, leaves, flowers and fruits of different citrus producing regions of the São Paulo State, with potential application as biocontrol agents for postharvest pathogens. Ninety-five yeast isolates were obtained from 14 counties in the São Paulo State. The phylloplane was the source of 90.5% of the isolates. Tests conducted in vitro, with G. candidum showed that ACBL-77 presented the highest inhibition of mycelial growth (35%) and both strains ACBL-68 and ACB-K1 (Saccharomyces cerevisiae), provided the highest values of inhibitions of conidia germination, 83 and 82%, respectively. When the control of sour rot in fruits of ´Pera´ sweet Orange was evaluated, three isolates (ACBL-23, ACBL-44 and ACBL-77) were the most effective in controlling the disease in a preventive and curative way. In in vitro assays with P. digitatum, five yeast strains (ACBL-76, ACBL-82, ACBL-84 and ACBL-87) inhibited the mycelial growth with values above 80%. However, when the ability of yeast to control green mold was evaluated on orange fruits, only two isolates (ACBL-82 and ACBL-86) were able to decrease the progress and also the incidence of the disease when used preventively. Eight isolates inhibited the mycelial growth of P. italicum above 80%, and the isolate ACBL-04 provided 100% of inhibition. In in vivo assays, four isolates (ACBL-04, ACBL-05, ACBL-08 and ACBL-11) were effective in reducing the progress of blue mold as well as in inhibiting the incidence of disease when applied preventively