Selenium is an important element in physiological and metabolic processes. Due to low Se concentration in most of the soils, strategies as enrichment and biofortification have been used to increase ...its incorporation in food. The fungus has capacity to absorb, accumulate and transform Se inorganic into organic compounds. However, the concentration and chemical forms of Se used for enrichment can affect the mycelial growth and mushrooms production. Thus, the aim of this study was to analyze the capacity of Pleurotus ostreatus in absorb, accumulate and tolerate growing concentrations of different Se chemical forms. In the disc of agar with mycelium was added 20 mL of PDA medium and Se concentration (0-200 mg L-1) in the forms of sodium selenite, sodium selenate or selenomethionine (SeMet). The greatest inhibition of mycelial growth and biomass production were observed in highest Se concentration. Regardless of the Se level, SeMet and sodium selenite were more harmful to the P. ostreatus growth than sodium selenate. However, the highest Se accumulation in the mycelium was observed in culture medium with sodium selenite. Thus, Se supplementation in the forms of sodium selenite was more indicated to enrichment of P. ostreatus mushrooms than sodium selenate and SeMet.
After the collapse of Fundão Dam in Mariana‐MG, Brazil, the discharge of iron ore mining waste into the Doce River watershed negatively impacted the landscape. Monitoring the composition and species ...richness of soil microbiota may be useful bioindicators of ecosystem recovery. This study aimed to compare soil chemical properties, total fungal species, and arbuscular mycorrhizal fungi (AMF) in sites unaffected and affected by mining tailings in the first 3 years after the collapse of Fundão Dam. Soil and root samples were collected in dry and rainy seasons over 3 years in unaffected (adjacent forest and pasture) and affected areas (REC1, REC2, and PASTrec) by mine tailings. Changes in soil chemical properties over the sampling period were measured by routine chemical analyses. Total fungi in the soil was determined by high‐throughput sequencing. AMF community was evaluated using spore number, root colonization, and denaturing gradient gel electrophoresis. Affected sites had higher ranges of pH and lower soil organic matter than unaffected sites. Revegetation had a positive effect on soil fungal community. Increased similarity in AMF DGGE analysis was observed in the two sampling sites over time. A high similarity of total fungi and AMF was observed between REC and pasture areas, suggesting that revegetation strategy employed may be heading towards a pasture condition. Thus, post‐disturbance analysis of this study was important to evaluate of ecosystem recovery affected by the rupture of iron ore mining dam and demonstrated that the soil microbiota was a sensitive bioindicator in this long path of ecosystem recovery.
Weeds and soil microorganisms interact with each other in the soil/root interface, promoting the development and establishment of both. The objective of this study was to evaluate the growth and ...nutrient accumulation in eight species of weeds (Ageratum conyzoides L., Bidens pilosa L., Cenchrus echinatus L., Conyza bonariensis L., Echinochloa crus-galli L., Eleusine indica L. Ipomoea grandifolia L. and Lolium multiflorum L.) and in bean and corn crops grown for 50 days in a substrate fumigated with methyl bromide. Assessments relating to the height, leaf area, leaf number, dry weight of shoots and roots and relative content of nutrients were carried out 50 days after seedling emergence. A positive effect of soil fumigation was observed on the growth, leaf number, leaf area, plant height and accumulation of nutrients in monocot weeds in relation to dicots. Conyza bonariensis was the most affected by soil fumigation, with levels of dry matter, leaf number, leaf area, height and accumulation of nutrients approximately 50% lower than plants grown in normal soil. Fumigation also influenced the growth cycle of the plants, which was lower for B. pilosa, E. indica and C. echinatus. We also observed a 20 and 30% lower phosphorus accumulation in Bidens pilosa and Conyza bonariensis, respectively, when grown in the sterilized soil. Overall, the bean and corn crops were less affected by soil fumigation than the weeds. Keywords: rhizosphere, soil microorganisms, Conyza bonariensis, methyl bromide. Plantas daninhas e microrganismos do solo se interagem na interface solo/raiz promovendo vantagens para o desenvolvimento e estabelecimento de ambos. Objetivou-se com este trabalho avaliar o crescimento e o acumulo de nutrientes em oito especies de plantas daninhas (Ageratum conyzoides L., Bidens pilosa L., Cenchrus echinatus L., Conyza bonariensis L., Echinochloa crus-galli L., Eleusine indica L., Ipomoea grandifolia L. e Lolium multiflorum L.) e nas culturas de feijao e milho, cultivadas, por 50 dias, em substrato fumigado com brometo de metila. Avaliacoes referentes a altura, area foliar, numero de folhas, materia seca da parte aerea e das raizes e teor relativo dos nutrientes, foram realizados aos 50 dias apos emergencia das plantulas. Observou-se efeito positivo da fumigacao do substrato no crescimento, numero de folhas, area foliar, altura de plantas e acumulo de nutrientes nas plantas daninhas gramineas em relacao as dicotiledoneas. Conyza bonariensis foi a mais afetada pela fumigacao do solo, apresentando indices de materia seca, numero de folhas, area foliar, altura e acumulo de nutrientes em torno de 50% menores em relacao as plantas crescidas em solo normal. A fumigacao influenciou tambem o ciclo vegetativo das plantas, sendo este menor para as especies B. pilosa, E. indica e C. echinatus. Observou-se, ainda, acumulo de fosforo 20 e 30% menor em plantas de Bidens pilosa e Conyza bonariensis, respectivamente, quando cultivadas em solo esterilizado. As culturas de feijao e milho foram menos afetadas pela fumigacao do solo em comparacao as plantas daninhas. Palavras-chave: rizosfera, microrganismos do solo, Conyza bonariensis, brometo de metila.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A MICROBIOLOGIA NO CONTEXTO DA AGROECOLOGIA Prates Junior, Paulo; Soares da Silva, Marliane de Cássia; Cerqueira Melo, Rita de Cássia ...
Revista brasileira de extensão universitária,
08/2018, Letnik:
9, Številka:
2
Journal Article
Recenzirano
Resumo: A extensão universitária tem por objetivo instituir práticas cidadãs de pesquisa e ensino. Nesse contexto, o Núcleo de Estudos em Microbiologia Agrícola (NEMA), da Universidade Federal de ...Viçosa (UFV), tem desenvolvido atividades de extensão junto à comunidade de Viçosa e região, para o intercâmbio de experiências em pesquisa, ensino e extensão relacionadas à Microbiologia Agrícola. O presente artigo apresenta os primeiros resultados do projeto de extensão universitária desenvolvido pelo NEMA junto à Escola Família Agrícola (EFA) Puris, que adota a Pedagogia da Alternância e tem a Agroecologia como eixo norteador, visando à articulação de atividades práticas e teóricas, em tempos e espaços que se alternam entre a escola e a comunidade na qual os educandos estão inseridos. As três intervenções realizadas até o presente momento abordaram os seguintes temas: demonstração dos micro-organismos no ambiente e o papel das micorrizas; produção, comercialização e consumo de cogumelos; compostagem e produção de alimentos fermentados. No total, as atividades envolveram cerca de 65 educandos do Ensino Médio, 5 monitores da EFA e 24 acadêmicos, dentre os quais professores, técnicos, graduandos e pós-graduandos da UFV. Essas intervenções têm proporcionado um estímulo à curiosidade, antes pouco ofertada, sobre o mundo microbiano e suas aplicações, além de instigar o interesse pelo conhecimento científico e proporcionar novos desafios de ensino e extensão para os acadêmicos envolvidos.
Palavras-chave: Agricultura familiar, Microbiologia agrícola, Universidade Federal de Viçosa
The microbiology in the context of the agroecology: extension activity in the Puris Agricultural Family School
Abstract: The university extension aims to establish citizen practices in research and teaching. In this context, the “Núcleo de Estudos em Microbiologia Agrícola (NEMA)”, from Universidade Federal de Viçosa – UFV(Viçosa, Minas Gerais State, Brazil), has developed extension activities in Viçosa and region for the exchange of experiences in research, teaching and extension related to Agricultural Microbiology. This paper presents the first results of the university extension project developed by NEMA at the Puris Agricultural Family School (EFA), which adopts the Pedagogy of Alternation for articulating practical and theoretical activities, in times and spaces concatenated between the school and the community in which students are inserted. The three interventions carried out until here were related to the demonstration of microorganisms in the environment and the role of mycorrhizae, the production, marketing and consumption of mushrooms, and the composting and production of fermented foods. In total, about 65 high school students, 5 EFA’s monitors and 24 academics and staffs from UFV were involved in the activities. These interventions have provided a stimulus to the curiosity, barely offered before, about the microbial world and their applications. Also, it has instigated the interest for the scientific knowledge and enabled new teaching and extension challenges for the academics involved.
Keywords: Family Farming, Agricultural Microbiology, Viçosa Federal University
La microbiología en el contexto de la agroecología: extensión universitaria en la Escuela de la Familia Agrícola Puris
Resumen: La extensión universitaria se caracteriza como un proceso de construcción de relaciones entre la sociedad y la Universidad, con el objetivo de establecer prácticas ciudadanas de investigación y enseñanza. En este contexto, el “Núcleo de Estudos em Microbiologia Agrícola (NEMA)”, de la Universidade Federal de Viçosa - UFV (Viçosa, Minas Gerais, Brasil), ha desarrollado actividades de extensión junto a la comunidad de Viçosa y región para el intercambio de experiencias de investigación, enseñanza y extensión relacionadas al área de Microbiología Agrícola. El presente artículo presenta los primeros resultados del proyecto de extensión universitaria desarrollado por el NEMA junto a la Escuela de la Familia Agrícola (EFA) Puris, que adopta la Pedagogía de la Alternancia, buscando la articulación de actividades prácticas y teóricas, en tiempos y espacios que se alternan entre la escuela y la comunidad en la cual los estudiantes están insertados. Las tres intervenciones realizadas hasta el momento abordaron los siguientes temas: demostración de los microorganismos en el medio ambiente y el papel de las micorrizas; producción, comercialización y consumo de champiñones; compostaje y producción de alimentos fermentados. En total, las actividades involucraran alrededor de 65 estudiantes, 5 monitores de la EFA y 24 alumnos de la UFV. Estas intervenciones han proporcionado un estímulo a la curiosidad, antes poco ofrecida, sobre el mundo microbiano y sus aplicaciones, además de instigar el interés por el conocimiento científico.
Palabras-clave: Escola familia Agrícola, Microbiología agrícola, Universidad Federal de Viçosa
The fungus Pochonia chlamydosporia is one of the most studied biological agents used to control plant-parasitic nematodes. This study found that the isolates Pc-3, Pc-10 and Pc-19 of this fungus ...promote the growth of tomato and lettuce seedlings. The isolate Pc-19 colonized the rhizoplane of tomato seedlings in only 15 days and produced a large quantity of chlamydospores. This isolate was able to use cellulose as a carbon source, in addition to glucose and sucrose. Scanning electron microscopy (SEM) revealed that hyphae of the P. chlamydosporia isolate Pc-10 penetrated the epidermal cells of the tomato roots. These three P. chlamydosporia isolates promote the growth of tomato and lettuce. Keywords: Lactuca sativa, nematophagous fungus, rhizosphere colonization, Solanum lycopersicum, Verticillium chlamydosporium. O fungo Pochonia chlamydosporia e um dos mais estudados agentes de controle biologico de fitonematoides. Neste estudo foi demostrado que os isolados Pc-3, Pc-10 e Pc-19 do fungo promovem o crescimento de plantulas de tomate e alface. O isolado Pc-19 colonizou o rizoplano de mudas de tomate em apenas 15 dias e produziu grande quantidade de clamidosporos. O isolado foi capaz de utilizar celulose como fonte de carbono, tanto quanto glicose e sacarose. Em estudos realizados por microscopia eletronica de varredura (MEV), foi possivel observar que hifas do isolado Pc-10 penetraram as celulas epidermicas das raizes de tomateiro. Os tres isolados de P. chlamydosporia promovem o crescimento de tomateiro e alface. Palavras-chave: Lactuca sativa, fungo nematofago, colonizacao da rizosfera, Solanum lycopersicum, Verticillium chlamydosporium.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The mushroom Pleurotus ostreatus has nutritional and medicinal characteristics that depend on the growth substrate. In nature, this fungus grows on dead wood, but it can be artificially cultivated on ...agricultural wastes (coffee husks, eucalyptus sawdust, corncobs and sugar cane bagasse). The degradation of agricultural wastes involves some enzyme complexes made up of oxidative (laccase, manganese peroxidase and lignin peroxidase) and hydrolytic enzymes (cellulases, xylanases and tanases). Understanding how these enzymes work will help to improve the productivity of mushroom cultures and decrease the potential pollution that can be caused by inadequate discharge of the agroindustrial residues. The objective of this work was to assess the activity of the lignocellulolytic enzymes produced by two P. ostreatus strains (PLO 2 and PLO 6). These strains were used to inoculate samples of coffee husks, eucalyptus sawdust or eucalyptus bark add with or without 20 % rice bran. Every five days after substrate inoculation, the enzyme activity and soluble protein concentration were evaluated. The maximum activity of oxidative enzymes was observed at day 10 after inoculation, and the activity of the hydrolytic enzymes increased during the entire period of the experiment. The results show that substrate composition and colonization time influenced the activity of the lignocellulolytic enzymes.
Prokaryotes play crucial roles in the rehabilitation process to restore the ecological integrity of disturbed areas. This work reports on the profiles of N‐fixing microorganisms and Actinobacteria, ...from DGGE, the prokaryotic composition from next‐generation sequencing (NGS) and physicochemical soil characteristics. We compared a deactivated mining site where mining ended about 10 years ago, when the revegetation process was begun (RV), and a reference site, with natural vegetation (NT), both located at Retiro das Almas Mine, in the Quadrilátero Ferrífero region, Minas Gerais, Brazil. In both sites, the most abundant archaeal and bacterial groups included Euryarchaeota, Thaumarchaeota, Proteobacteria, Actinobacteria, Acidobacteria, and Verrucomicrobia and revealed differences in their ecological metrics and distribution. Proteobacteria and Actinobacteria were most abundant in RV sites, while Acidobacteria and Verrucomicrobia were most abundant in NT sites. Less abundant phyla, such as Bathyarchaeota (Archaea) and GAL 15 (Bacteria) were found only in NT, while Gracilibacteria, Ignavibacteriae BJ‐169, and BRC1 were only found in RV. The majority of identified bacterial genera were shared by RV and NT. Soil P, pH, and particle density were most significant (p < 0.05) in RV, while Fe, Ca, organic matter, potential acidity and dispersed clays, were most significant (p < 0.05) in NT, showing differences in soil characteristics, which led the prokaryotic composition in these sites. DGGE profiles of N‐fixing microorganisms revealed N‐fixing predominance in both sites, although after 10 years prokaryotes diversity increased in RV site. Our results revealed that prokaryotic structure and composition are indicative of RV soil resilience.
Colonização micorrízica em plantios de eucalipto Campos, Daniela Tiago da Silva; Silva, Marliane de Cássia Soares da; Luz, José Maria Rodrigues da ...
Revista árvore,
10/2011, Letnik:
35, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A associação micorrízica é advinda da associação simbiótica entre alguns fungos do solos e da maioria das raízes das plantas. O eucalipto possui a capacidade de se associar com dois tipos de ...micorrizas, a micorriza arbuscular e a ectomicorriza, o que depende muito da sua idade. Este trabalho objetivou avaliar a taxa de colonização por fungos micorrízicos arbusculares (MA) e ectomicorrízicos (ECM) e o número de esporos de fungos micorrízicos arbusculares em plantios comerciais de Eucalyptus grandis e Eucalyptus urophylla, com diferentes idades e manejos, no período de dezembro de 2002 a fevereiro de 2004, na região leste de Minas Gerais, Brasil. Em todas as coletas e em todas as idades dos plantios, foram encontradas MA, e ECM e a média geral da colonização por fungos micorrízicos arbusculares (FMA) foi de 26%. O número médio de esporos desses fungos de 374,7 por 100 g de solo e a colonização por fungos ectomicorrízicos (FECM) de 20,2%. As maiores porcentagens de colonização por FECM foram observadas em áreas de plantios mais jovens, mas a sua maior diversidade foi observada nas áreas de plantios mais velhos. Conclui-se que a época de coleta, a idade do plantio e o manejo do solo afetam a colonização micorrízica e também a diversidade de fungos ECM e que a sucessão de eucalipto com FMA-FECM não é regra e é muito influenciada pelo tipo de manejo.
Mycorrhyzal association is the symbiotic association among some soil fungus and most plant roots. Eucalyptus has the capacity of associating with two types of mychorrizal, arbuscular and ectomycorrhizal mycorrhizal,depending of its age. The objective of this work was to evaluate colonization rates by arbuscular mycorrhizal fungi (AM) and ectomycorrhizal fungi (ECM) and the number of spores of arbuscular mycorrhizal fungi in in commercial plantations of Eucalyptus grandis and Eucalyptus urophylla, at different ages and managements practices, from December 2002 to February, 2004, in eastern region of Minas Gerais, Brazil. In all periods of sampling and at all ages of the plant, it was found both AM and ECM and the colonization general mean by arbuscular mycorrhizal fungi (AMF) was 26%. The average number of spores of those fungi was 374.7 per 100 g of soil and colonization by ectomycorrhizal fungi (EMF) was 20.2 %. Most percentages of colonization by EMF were observed in areas with younger plantations, but it greatest diversity was observed in older plantation areas. It can be concluded that sampling period, age of the plantation and soil management practices affect mycorrhizal colonization and also ECM fungi diversity and succession of eucalyptus with AM-ECM is not a rule and it is strongly affected by management.
Colonização micorrízica em plantios de eucalipto Campos, Daniela Tiago da Silva; Silva, Marliane de Cássia Soares da; Luz, José Maria Rodrigues da ...
Revista árvore,
10/2011, Letnik:
35, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A associação micorrízica é advinda da associação simbiótica entre alguns fungos do solos e da maioria das raízes das plantas. O eucalipto possui a capacidade de se associar com dois tipos de ...micorrizas, a micorriza arbuscular e a ectomicorriza, o que depende muito da sua idade. Este trabalho objetivou avaliar a taxa de colonização por fungos micorrízicos arbusculares (MA) e ectomicorrízicos (ECM) e o número de esporos de fungos micorrízicos arbusculares em plantios comerciais de Eucalyptus grandis e Eucalyptus urophylla, com diferentes idades e manejos, no período de dezembro de 2002 a fevereiro de 2004, na região leste de Minas Gerais, Brasil. Em todas as coletas e em todas as idades dos plantios, foram encontradas MA, e ECM e a média geral da colonização por fungos micorrízicos arbusculares (FMA) foi de 26%. O número médio de esporos desses fungos de 374,7 por 100 g de solo e a colonização por fungos ectomicorrízicos (FECM) de 20,2%. As maiores porcentagens de colonização por FECM foram observadas em áreas de plantios mais jovens, mas a sua maior diversidade foi observada nas áreas de plantios mais velhos. Conclui-se que a época de coleta, a idade do plantio e o manejo do solo afetam a colonização micorrízica e também a diversidade de fungos ECM e que a sucessão de eucalipto com FMA-FECM não é regra e é muito influenciada pelo tipo de manejo.
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