Broad Escovopsis-inhibition activity of Pseudonocardia associated with Trachymyrmex ants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Novel Phialophora species from leaf-cutting ants (tribe Attini)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leaf-cutting ants: an unexpected microenvironment holding human opportunistic black fungi

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Micro-fungos de interesse para o setor de petróleo, gás e biocombustíveis

Oil is a hydrocarbon mixture of various sizes, including saturated and aromatic compounds. Natural gas is a mixture of gaseous hydrocarbons and its main component is methane. In our society, the great demand for these fuels requires fast extraction, transportation and refining, increasing the number of accidents that compromise the environment. Oil is a finite resource and it is necessary to reduce the problems related to the question concerning environmental pollution which has encouraged the search for alternative fuel sources in our country. So today we have two major biofuels: ethanol and biodiesel. Concurrently, many studies have been done directed toward the isolation of microorganisms capable of degrading petrochemical industrial wastes, most of them using as a source of isolation soil and water collected in a contaminated environment. Isolation from alternative substrates has emerged as a new strategy that has provided satisfactory results. In this work, we present the leaf-cutter ants of the Attini tribe as a source for the isolation of micro-fungi with the potential for hydrocarbon degradation. These insects have a social way of life and a highly specialized system of intra and interspecific communication, which is based on the recognition of individuals through volatile chemical compounds, the majority hydrocarbons, stored in their exoskeleton. The micro-environment exoskeleton of Attini ants (genus Atta) used in this work proved to be a rich source of microbial biodiversity, as other studies have found. The flotation isolation technique applied here allowed the achievement of 214 micro-fungi, 118 representatives of the dematiaceous fungi group and 96 hyaline filamentous fungi. They were submitted to toluene degradation tests and at least one strain of each genus presented good results, namely Teratosphaeria, Exophiala, Cladosporium, Penicillium, Aspergillus... (Complete abstract click electronic access below)

Fungos fitopatógenos associados às formigas cortadeiras (Formicidae: Tribo Attini)

The ants of genus Atta belong to the Attine tribe (order Hymenoptera, family Formicidae, subfamily Myrmicinae) and are commonly known as leaf-cutting ants for having the habit of cutting several vegetable species used as substrate for growing mutualistic fungus (Agaricales: Lepiotaceae). Recent studies showed that, in addition to that, other fungi may occur in the nests in a dorment state or participate in the functioning dynamic of this symbiosis. Researches related to surveys of fungus biodiversity in nests of different Atta species have found important phytopathogenic representatives. In Brazil, studies about integrated management of plagues, developed by Embrapa Meio Ambiente (Embrapa Environment), point out the need of higher investments in projects that involve the phytopathogenic transmission by insects in order to reduce costs to control them or minimize environmental impact. The purpose of this study was to broaden the knowledge about the ecology of these fungi, isolating and identifying species associated with Attine tribe ants, thus understanding the scope of pathogenic and phytopathogenic species spread by these ants. For that reason, gynes were collected from Atta laevigata and Atta capiguara anthills located at Unesp Botucatu (São Paulo, Brazil) campus. In order to isolate the fungus, the mineral oil floating technique was used. The identification of the isolated fungi was done based on microscopic and molecular characteristics using DNA ribosomal sequencing. The most highly abundant genera found so far were: Cladosporium, Exophiala, Penicillium, Acremonium, Phialophora and Teratosphaeria. Representatives of the genera Exophiala, Phialophora and Cladosporium may be human pathogens, whereas Teratosphaeria and Penicillium are related to diseases in Eucalyptus and citric fruits, respectively. The results show that these ants may host important fungal species besides the ones already... (Complete abstract click electronic access below)

Fungos melanizados associados a formigas cortadeiras (Formicidae: Tribo Attini)

Leafcutter ants are considered pests in agriculture for their impact in human crops, as they behave utilizing foliar fragments to raise their simbiont fungi (Agaricales: Lepiotaceae) inside their nest. Recent studies have noticed that other fungi may be associated to ants inside their nests, for instance, fungi with melanized wall, known by “dematiaceous”. Historically, many black fungi have been noticed as fitopathogens of many plant cultures with economic importance, highlighting dematiaceous ecological behavior importance in this study. This investigation had the purpose of amplifying ecological knowledge of this fungi, isolating and identificating dematiaceous fungi found in Attini nests, having the intention of understanding plant pathogens dispersion by ants. In this work, 66 isolates were characterized in the following genus: Aspergillus, Penicillium, Paecilomyces, Oxyporus, Rhodotorula, Bipolaris, Curvularia, Fusarium, Giberella, Paraphaeosphaeria, and Cladosporium. The genus Bipolaris, Curvularia, Fusarium and Giberella are known for their opportunistic behaviour, with some published human infections in literature. Fusarium is a notorious fitopathogen, with wide number of descriptions and studies involving pathogenicity development, biochemistry and genetics. The isolates outline is of phyto – associated (phytopathogens, endophytic or epiphitic), fulfilling this work intention in alarming fungi capacity of dispersal by ants. The comprehension of phytopathogenical processes may be clarified based on the knowledge of oportunistics fungi that may utilize ants bodies for their own dispersal. The identification of isolates with capacity of infecting humans brings out public health issues.

Associação entre mesoplasma sp e formigas da tribo Attini (Hymenoptera, formicidae)

As formigas da tribo Attini apresentam reconhecida simbiose com microrganismos: fungos mutualistas basidiomicetos nas famílias Lepiotaceae e Pterulaceae cultivados pelas formigas, bactérias actinomicetas ou no gênero Burkholderia produtoras de antibióticos contra fungos entomopatogênicos, fungos ascomicetos do gênero Escovopsis micófagos para o mutualista, e comensais como fungos, leveduras e bactérias que degradam celulose. Um novo mutualista é descrito no presente trabalho: uma espécie de bactéria no gênero Mesoplasma, detectada via PCR para 16S no DNA genômico de Attini derivadas (gêneros Acromyrmex, Atta, Serycomyrmex e Cyphomyrmex), intermediárias (Trachymyrmex) e basais (Apterostigma, Mycetarotes, Mycocepurus e Mycetagroicos). Uma única linhagem de Mesoplasma com baixíssima diversidade 16S esteve presente nas Attini, mas não em formigas de tribos filogeneticamente próximas a Attini, como Dolichoderini (Tapinoma sp), Camponotini (Camponotus sp), Cephalotini (Cephalotes sp), Crematogastrini (Crematogaster sp), Pheidolini (Pheidole sp) e Ponerini (Pachycondyla sp), indicando uma simbiose Mesoplasma-Attini recente e específica.

Antagonismo de actinobactérias isoladas de Trachymyrmex frente ao fungo parasita Escovopsis

As formigas da tribo Attini mantêm uma associação com actinobactérias encontradas nos biofilmes presentes no integumento desses insetos. Dentre as actinobactérias associadas às formigas Attini, os gêneros Pseudonocardia e Streptomyces são considerados prevalentes. Estudos indicam que essas bactérias auxiliam na defesa do jardim contra patógenos através da secreção de compostos antimicrobianos. Recentemente foi sugerido que tais bactérias podem ser importantes na defesa do próprio inseto, especialmente contra entomopatógenos. Duas teorias principais foram propostas para explicar as interações entre actinobactérias, formigas Attini e o microfungo parasita Escovopsis. Uma delas defende a coevolução entre esses organismos e a outra rejeita a existência da mesma, argumentando que a interação formiga-actinobactéria é uma simbiose aberta. Neste trabalho, avaliamos a interação entre actinobactérias e Escovopsis em experimentos in vitro. Um total de 14 linhagens de actinobactérias, compreendendo 12 de Pseudonocardia, uma de Streptomyces e uma de Actinoplanes, isoladas de Trachymyrmex (um gênero de formiga Attini não cortadeira) foram testadas frente a quatro linhagens de Escovopsis. Os Escovopsis foram isolados tanto de jardins de fungos de formigas Trachymyrmex quanto de cortadeiras de folhas (Acromyrmex e Atta). O crescimento micelial de Escovopsis (em cm²) foi medido na presença e na ausência (controle) das actinobactérias. Os resultados demonstraram que todas as actinobactérias testadas inibiram Escovopsis, mas as taxas de inibição foram variáveis dependendo da linhagem da actinobactéria (p < 0,05). A linhagem de Streptomyces foi a mais efetiva, corroborando dados da literatura que indicam que outros micro-organismos, além de Pseudonocardia, também apresentam ação inibitória frente à Escovopsis... (Resumo completo, clicar acesso eletrônico abaixo)

Natureza do antagonismo entre fungos oportunistas e o fungo cultivado pelas formigas cortadeiras

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mitochondrial and peroxisomal population in post-pharyngeal glands of leaf-cutting ants after lipid supplementation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leaf-cutter ant fungus gardens are biphasic mixed microbial bioreactors that convert plant biomass to polyols with biotechnological applications

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

What is the stimulus for the excavation of fungus chamber in leaf-cutting ants?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative study of resistance to heat in two species of leaf-cutting ants

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Phoretic behaviour of attacobius attarum (Roewer, 1935) (Araneae: Corinnidae: Corinninae) dispersion not associated with predation?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)