Endophytic bacteria from banana cultivars and their antifungal activity.

Endophytic microorganisms consist of fungi, bacteria, and actinomycetes that play important roles in the process of plant adaptation to the environment. Currently, the natural associations between microorganisms and plant species are being explored for a large number of biotechnological applications. In this study, 122 endophytic bacteria were isolated from 5 cultivars of Musa spp from the state of Amazonas (Brazil). Four strains were selected because they exhibited antagonistic activities against Fusarium oxysporum f. sp cubense and Colletotrichum guaranicola, with inhibitions ranging from 19 to 30% and 27 to 35%, respectively. Phylogenetic analysis of the 16S rDNA regions of these bacteria with antifungal activity showed that they are phylogenetically related to 3 different species of Bacillus - B. amyloliquefaciens, B. subtilis subsp subtilis, and B. thuringiensis

Operational taxonomic units (OTUs) of endophytic bacteria isolated from banana cultivars in the Amazon.

This study aimed to isolate and characterize (the genetic diversity of) endophytic bacteria isolated from the FHIA 18 banana cultivar (grown in the Amazon Basin)

Seleção de bactérias endofíticas com potencial para controle biológico in vitro de Fusarium oxysporum f. sp. cubense.

Controle biológico é o uso de organismos através de uma ação direta sobre outro antagônico, podendo este atuar por meio de antibiose, parasitismo, competição, predação, ou hipovirulência. O controle biológico tem sido utilizado em diferentes campos da biologia, principalmente na entomologia e fitopatologia, contribuindo em uma primeira fase na transição agroecológica para a redução do uso de agroquímicos. O mal-do-Panamá é uma doença endêmica por todas as regiões produtoras de banana do mundo, causada pelo fungo Fusarium oxysporum f. sp. cubense (E.F. Smith) Sn e Hansen., que apresenta alta capacidade de sobrevivência mesmo na ausência do hospedeiro. Uma forma de controle de F. oxiporum f. sp. cubense pode ser o uso de bactérias endofíticas com intuito controlar e inibir o desenvolvimento do mesmo. Deste modo o presente teve como objetivo selecionar bactérias endofíticas de bananeira para uso no controle biológico in vitro de F. oxysporum f. sp. cubense. Foram analisados 148 isolados obtidos de cultivares de bananeiras Pisang, FHIA18, BRS conquista, e Pacovan. O teste de antagonista in vitro entre F. oxysporum f. sp. cubense e bactétias endofíticas foi realizado em meio TSB. Fragmentos de micélio foram incubados à 28ºC (fotoperíodo de 12 horas) e após 3 dias crescimento as batectérias endofíticos foram inoculados e incubados à 28ºC (fotoperíodo de 12 horas) durante 4 dias. Das 148 bactérias avaliadas, nenhuma apresentou halo de inibição, contudo 18 apresentaram atividade antagônica contra F. oxysporum f. sp. cubense por competição. Os dados obtidos indicam que o agente de biocontrole apresenta boa capacidade de competição por espaço e nutrientes. Bactérias isoladas de bananeiras dos diferentes cultivares, apresentaram o mesmo potencial para controle de F. oxysporum f. sp. cubense, in vitro

Coleção espécies arbóreas da Amazônia: glossário de termos botânicos.

bitstream/item/223529/1/Colecao-especies-arboreas.pdfVolume especial

Isolation and identification of pigment-producing endophytic fungi from the Amazonian species Fridericia chica.

Pigments of fungal origin have aroused increasing interest in the food dye and cosmetic industries since the global demand for natural dyes has grown. Endophytic microorganisms are a source of bioactive compounds, and Amazonian plant species can harbor fungi with a wide range of biotechnological applications. Popularly known in Brazil as crajiru, Fridericia chica is a medicinal plant that produces a red pigment. In this study, a total of 121 fungi were isolated in potato dextrose agar from three plants. We identified nine pigment-producing endophytic fungi isolated from branches and leaves of F. chica. The isolates that showed pigment production in solid media were molecularly identified via multilocus analysis as Aspergillus welwitschiae, A. sydowii, Curvularia sp., Diaporthe cerradensis (two strains), Hypoxylon investiens, Neoscytalidium sp. (two strains) and Penicillium rubens. These isolates were subjected to submerged fermentation in two culture media to obtain metabolic extracts. The extracts obtained were analyzed in terms of their absorbance between 400 and 700 nm. The pigmented extract produced by H. investiens in medium containing yeast extract showed maximum absorbance in the red absorption range (UA700 = 0.550) and significant antioxidant and antimicrobial activity. This isolate can thus be considered a new source of extracellular pigment

Leishmanicidal activity of the venoms of the Scorpions Brotheas amazonicus and Tityus metuendus

Abstract Leishmaniasis is a vector-transmitted zoonosis caused by different species of the genus Leishmania, with a wide clinical spectrum. It is a public health problem aggravated by a series of limitations regarding treatment. In the search for new therapeutic alternatives, scorpion venoms are a source of multifunctional molecules that act against the natural resistance of pathogens. This work evaluated the antileishmanial potential of Brotheas amazonicus and Tityus metuendus venoms against the promastigote forms of Leishmania amazonensis e Leishmania guyanensis. The venoms of B. amazonicus and T. metuendus were evaluated for their constituents using Fourier Transform Infrared (FTIR). Growth inhibition and death of promastigotes were evaluated in the presence of diferente crude venom concentrations (100 µg/mL, 50 µg/mL, 10 µg/mL, 1 µg/mL) after one hour of incubation at 25 °C. The FTIR spectra of both venoms exhibited bands in approximate regions, revealing that both exhibit similar functional groups. Crude venom from both scorpion species showed similar or superior leishmanicidal effects to the standart drug N-methylglucamine antimoniate. At the highest concentration of 100 µg/mL, cultures of L. guyanensis treated with the venom of B. amazonicus showed the highest mortality percentages, above 28%, while T. metuendus venom showed the highest activity against L. amazonensis, with mortality above 7%. This preliminar study demonstrates that B. amazonicus and T. metuendus venoms can be important tools in the search for new drugs Against leishmaniasis. Next step involves evaluating the activity against the amastigote forms and purifying the venom proteins in order to identify the best anti-leishmania candidates