Microbiologia
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11840
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Item Cyrtopodium paludicolum germination with two Tulasnella isolates(Acta Botanica Brasilica, 2018-01) Carvalho, Otieres Cirino de; Paiva Neto, Vespasiano Borges de; Padilha, Daly Roxana Castro; Veloso, Tomás Gomes Reis; Bocayuva, Melissa Faust; Soares, Deanna Carla Oliveira; Kasuya, Maria Catarina MegumiSymbiosis between orchid seeds and mycorrhizal fungi has been reported to be a determining factor in the success of germination and protocorm development in vitro. Th e aim of this study was to isolate and identify by molecular analysis the mycorrhizal fungus associated with Cyrtopodium paludicolum, and to evaluate its effi ciency in facilitating seed germination and development. Germination experiments were carried out using a fungus isolated from C. paludicolum (CH01) and Epidendrum secundum (M65), which has been successfully used a number of times in symbiotic germination. Th e experiments were conducted in a completely randomized design with treatments of CH01, M65 as well as under asymbiotic conditions. Th e mycobiont CH01 was successfully isolated from Cyrtopodium paludicolum and identifi ed as Tulasnella sp. Treatments with both fungi reached a higher germination percentage than under asymbiotic conditions, indicating no specifi city in the relationship between Cyrtopodium paludicolum and the fungi. Th e results presented have the potential to advance research into the propagation and conservation of C. paludicolum, a native of the Cerrado biome.Item Agroecological coffee management increases arbuscular mycorrhizal fungi diversity(Plos One, 2019) Prates Júnior, Paulo; Moreira, Bruno Coutinho; Silva, Marliane de Cássia Soares da; Veloso, Tomas Gomes Reis; Stürmer, Sidney Luiz; Fernandes, Raphael Bragança Alves; Mendonça, Eduardo de Sá; Kasuya, Maria Catarina MegumiAgroecology aims to maintain ecosystem services by minimizing the impact of agriculture and promoting the use of biological potential. Arbuscular mycorrhizal fungi (AMF) are elements which are key to improving crop productivity and soil quality. It is pertinent to understand how agricultural management in the tropics affects the AMF spatio-temporal community composition, especially in crops of global importance, such as coffee (Coffea arabica L.). Soil and root samples were collected from three localities under three management systems (agroecological, conventional and forest fragment), during the phenological stages of coffee (flowering, grain filling, harvesting). Spores were extracted for morphological identification and molecular community analysis by PCR–DGGE. Dendrograms were prepared and the bands were sequenced and analyzed by bioinformatics. No differences were observed in the richness of morphospecies between management systems, localities and period, but little is known about tropical species. Molecular analysis showed that the agroecological management system was similar to natural forest and with a higher diversity indices than conventional management. Locality and period of sample affect AMF community composition. It is necessary to associate classical taxonomic evaluations with molecular biological techniques because different approaches can lead to different outcomes. This study contributes to the understanding of the impact of agriculture management systems on AMF and provides evidence that agroecology is a management system applicable to sustainable coffee production.Item Expression of the nifH gene in diazotrophic bacteria in Eucalyptus urograndis plantations(Canadian Journal of Forest Research, 2016-02) Silva, Marliane de Cássia Soares da; Mendes, Igor Rodrigues; Paula, Thiago de Almeida; Dias, Roberto Sousa; Paula, Sérgio Oliveira de; Silva, Cynthia Canedo; Bazzolli, Denise Mara Soares; Kasuya, Maria Catarina MegumiA large proportion of eucalypt plantations in Brazil are located in areas with low soil fertility. The actions of microorganisms are of great importance for the cycling of nutrients, including nitrogen (N), that are essential for plant metabolism. Denaturing gradient gel electrophoresis (DGGE) was used to monitor and identify the total and active microorganisms involved in the N cycle in both the soil and root systems of a forest of Eucalyptus urograndis with sections that were fertilized with N or unfertilized. Quantitative real-time PCR was used to examine the expression of the nifH gene in N-fixing bacteria present in both the soil and root systems. According to the DGGE analysis, in the total and active populations of N-fixing bacteria, the presence and expression of the nifH gene were influenced by the winter and summer seasons and (or) N fertilization, respectively. DGGE band sequencing from total DNA samples showed that the most abundant group of diazotrophic bacteria belonged to Alphaproteobacteria in both the soil and root systems. Quantitative real-time PCR revealed that nifH expression was higher in the soil samples, especially in those that did not receive N fertilization. The differences in the composition of the total and active diazotrophic populations highlight the importance of evaluating the active populations, because they are effectively responsible for the biogeochemical transformation of N and also control its' availability to plants.Item Morphological and molecular characterization of Tulasnella spp. fungi isolated from the roots of Epidendrum secundum, a widespread Brazilian orchid(Symbiosis, 2014-02) Pereira, Marlon Corrêa; Coelho, Irene da Silva; Valadares, Rafael Borges da Silva; Oliveira, Sabrina Feliciano; Bocayuva, Melissa; Pereira, Olinto Liparini; Araújo, Elza Fernandes; Kasuya, Maria Catarina MegumiTulasnella spp. are the main fungal symbionts of Brazilian Epidendrum orchids. The taxonomy of these fungi is largely based on ITS rDNA similarity, but culture dependent techniques are still essential to establish the true biological entity of the mycobiont. The aim of this study was to characterize morphologically and molecularly 16 Tulasnella spp. fungi isolated from three different populations of E. secundum and to test the coincidences between morphological and molecular characterization. Two uninucleate rhizoctonia fungi, obtained from Oncidium barbaceniae, and two phytopathogenic isolates were included as outgroups. Qualitative and quantitative morphological characteristics were analyzed using multivariate statistics and were able to distinguish Ceratobasidium, Tulasnella and Thanatephorus genera and separate the isolates of Tulasnella spp. into two groups. Analysis of RAPD (Random Amplified Polymorphic DNA) and ITS rDNA sequences validated the morphological data. Symbionts of O. barbaceniae presented identity to ITS sequences of Ceratobasidium genus, while E. secundum isolates presented identity to two species of Tulasnella. We observed homogeneity among Tulasnella spp. obtained from a single population and from neighboring populations, but there was higher variability among isolates obtained from populations of regions that were farther apart. Morphological data associated with multivariate statistics proved to be a useful tool in the multi-level taxonomy of these orchid-associated fungi and in estimating the diversity of orchid mycorrhizal fungi.Item Production of edible mushroom and degradation of antinutritional factors in jatropha biodiesel residues(LWT - Food Science and Technology, 2013-03) Luz, José Maria Rodrigues da; Paes, Sirlaine Albino; Torres, Denise Pereira; Nunes, Mateus Dias; Silva, Juliana Soares da; Mantovani, Hilário Cuquetto; Kasuya, Maria Catarina MegumiThe elimination of antinutritional factors of the Jatropha curcas L. seed cake is important for decreasing environmental damage and adding economic value to this residue of the biodiesel industry. In this study, we analyzed the ability of Pleurotus ostreatus to degrade antinutritional factors and produce edible mushrooms using different proportions of the J. curcas seed cake as substrate. After 60 d of incubation at 25 °C, we observed 95% phytic acid and 85% tannins reductions, and high mushrooms productivity. There was no evidence of tannins or phytic acid in these mushrooms. Furthermore, the phorbol ester concentration observed in these mushrooms was around 1000-fold lower than that found in the non-toxic variety of J. curcas. Thus, P. ostreatus can degrade the antinutritional factors found in J. curcas seed cake. The jatropha seed cake can potentially be used for mushroom production, with high nutritional value, and animal ration, after treated by P. ostreatus, adding economic value to the biodiesel residue and avoiding inadequate disposal in the environment.Item Arbuscular mycorrhizal fungi (Glomeromycota) communities in tropical savannas of Roraima, Brazil(Mycological Progress, 2018-08-13) Kemmelmeier, Karl; Stürmer, Sidney Luiz; Moreira, Bruno Coutinho; Kasuya, Maria Catarina Megumi; Pereira, Gilmara Maria Duarte; Silva, Krisle daSavanna vegetation in the northern region of Brazil is jeopardized by several anthropogenic activities including cattle ranching and extensive agriculture, and soil biota of these ecosystems is virtually unknown. The soils in savannas are poor in nutrients, very acidic, and subject to drought, and under these conditions, arbuscular mycorrhizal fungi (AMF) are likely to play a key role on plant nutrition and improving soil structure. In this study, we surveyed AMF communities in five savanna locations in Roraima state, Northern Brazil. AMF species were identified using two approaches: field collected spores and trap cultures. Twenty-three AMF species were identified, including 21 species in field samples, 8 species in trap cultures, of which 15 and 2 were unique to field and trap culture samples, respectively. Gigaspora margarita, Dentiscutata heterogama, and Glomus sp1 were the most frequent species recovered from all locations. AMF communities were dominated by members of Gigasporaceae that accounted for 50 to 87% of the total species richness within each location. Spore numbers differed across locations and ranged from 5 to 25 spores 100 cm−3 soil. Redundancy analysis indicated that soil organic matter was the only selected predictor among soil parameters and correlated positively with occurrence of Glomus heterosporum. We conclude that savannas in Roraima harbor a high sporulating AMF species richness with communities dominated by members of Gigasporaceae and that organic carbon is an important edaphic factor influencing AMF community composition in this ecosystem.Item Effect of inoculation of symbiotic fungi on the growth and antioxidant enzymes’ activities in the presence of Fusarium subglutinans f. sp. ananas in pineapple plantlets(Acta Physiologiae Plantarum, 2016-09-06) Moreira, Bruno Coutinho; Prates Junior, Paulo; Jordão, Thuany Cerqueira; Silva, Marliane de Cássia Soares da; Stürmer, Sidney Luiz; Salomão, Luiz Carlos Chamhum; Otoni, Wagner Campos; Kasuya, Maria Catarina MegumiThe inoculation with symbiotic fungi, Arbuscular mycorrhizal fungi (AMF) and/or Piriformospora indica on the growth, nutrient absorption, and induction of antioxidant enzyme activities in plantlets of pineapple ‘Imperial’ (fusariosis-resistant) and ‘Pérola’ (fusariosis-susceptible) in the presence of Fusarium subglutinans f. sp. ananas was investigated. The experiment was comprised by two cultivars, with or without fungal inoculation (Claroideoglomus etunicatum, Rhizophagus clarus, and P. indica, a mixture of all the fungi, and the control—absence of fungal inoculation), with or without applying Fusarium conidia, and with four replicates. In both cultivars, nutrient absorption was higher in the AMF plantlets compared to those inoculated with P. indica or the control ones, although it was more efficient in ‘Imperial’ than in ‘Pérola’. Inoculation with AMF and/or P. indica as well as the pathogen influenced differently the activities of superoxide dismutase, catalase, glutathione reductase, peroxidase, and polyphenol oxidase, in the shoots or roots of pineapple plantlets in both cultivars. Inoculated plantlets with mixture of all the fungi also exhibited a better growth and nutrient absorption, and generally, the ‘Imperial’ responded better than ‘Pérola’. In addition, these plantlets developed better than the control even in the presence of pathogen, indicating that inoculation with AMF and/or P. indica may contribute to the production of more resistant propagative material. Increased antioxidant enzyme activity is a potential strategy for managing this plant for explore biological control as an alternative to reduce environmental and health impacts by reducing the use of fungicides.Item Arbuscular mycorrhizal fungal diversity in rhizosphere spores versus roots of an endangered endemic tree from Argentina: Is fungal diversity similar among forest disturbance types?(Applied Soil Ecology, 2016-02) Soteras, Florencia; Moreira, Bruno Coutinho; Grilli, Gabriel; Pastor, Nicolás; Mendes, Flávia Carneiro; Mendes, Daniele Ruela; Renison, Daniel; Kasuya, Maria Catarina Megumi; Souza, Francisco Adriano de; Becerra, AlejandraThe aim of this study was to compare the arbuscular mycorrhizal fungal (AMF) community of the rhizosphere and inside the roots of the perennial Polylepis australis tree. Three forest types differing in their structural complexity due to anthropogenic disturbances were chosen at three different sites at the high mountains of central Argentina. Rhizosphere spores and P. australis roots of four randomly selected trees were isolated from 36 soil samples, DNA was extracted and the 18S rDNA fragments were amplified by nested-PCR. The products were analyzed by DGGE and the bands were excised for sequencing. In total, 36 OTUs were defined from 56 DGGE bands successfully sequenced. Forest disturbance types showed similar communities of AMF, as rhizosphere spores and within the roots of P. australis. However, DGGE lustering showed mainly differences between rhizosphere spores and root-colonizing AMF. Members of Glomeraceae, Pacisporaceae, Acaulosporaceae and Gigasporaceae were shown in rhizosphere spore samples. Root samples showed only members of Acaulosporaceae and Gigasporaceae, which might be complementary in terms of soil resources exploration. The prevalence of the root system with their community of symbionts might explain the resilience of AMF soil communities to forests structural changes. This study presents evidence of a possible preference in the AMF–P. australis interaction.Item Enzymatic extract containing lignin peroxidase immobilized on carbon nanotubes: Potential biocatalyst in dye decolourization(Saudi Journal of Biological Sciences, 2016-02-11) Oliveira, Sabrina Feliciano; Luz, José Maria Rodrigues da; Kasuya, Maria Catarina Megumi; Ladeira, Luiz Orlando; Correa Junior, AryThe majority of the textile dyes are harmful to the environment and potentially carcinogenic. Among strategies for their exclusion, the treatment of dye contaminated wastewater with fungal extract, containing lignin peroxidase (LiP), may be useful. Two fungi isolates, Pleurotus ostreatus (PLO9) and Ganoderma lucidum (GRM117), produced the enzymatic extract by fermentation in the lignocellulosic residue, Jatropha curcas seed cake. The extracts from PLO9 and GRM117 were immobilized on carbon nanotubes and showed an increase of 18 and 27-fold of LiP specific activity compared to the free enzyme. Also, LiP from both fungi extracts showed higher Vmax and lower Km values. Only the immobilized extracts could be efficiently reused in the dye decolourization, contrary, the carbon nanotubes became saturated and they should be discarded over time. This device may offer a final biocatalyst with higher catalytic efficiency and capability to be reused in the dye decolourization process.Item Núcleo de Estudos em Microbiologia Agrícola (NEMA): integração e multiplicação de ações e conhecimentos(Revista ELO - Diálogos em Extensão, 2017-10-20) Prates Júnior, Paulo; Cerqueira, Alan Emanuel Silva; Veloso, Tomás Gomes Reis; Correia, Hilberty Lucas Nunes; Kasuya, Maria Catarina MegumiA troca de saberes tem grande importância para a ciência e estimula a dialética entre a razão e a emoção. Assim, surgiu o Núcleo de Estudos em Microbiologia Agrícola (NEMA) da Universidade Federal de Viçosa (UFV), com o objetivo de promover ações de ensino, pesquisa e extensão. O NEMA é subdividido em coordenações; essas despertam o voluntariado e a construção de um legado coletivo. O Dragon Dreaming tornou-se uma metodologia importante para a dinâmica do grupo, bem como os conceitos de Paulo Freire e Edgar Morin sobre conhecimento e respeito às diferenças. As atividades realizadas até o momento, como os Ciclos de Discussões em Bioinformática e Bioestatística, o Curso de Biossegurança, os Projetos "A importância da Microbiologia para a Agroecologia" e "Micro Cultural", são indicativos de avanços na integração do Departamento de Microbiologia e do nosso Programa de Pós-graduação e deste com a sociedade. Espera-se estimular o conhecimento crítico e ampliar as conexões entre ensino, pesquisa e extensão.