Since the formal description of fungi in the genus Escovopsis in 1990, only a few studies have focused on the systematics of this group. For more than two decades, only two Escovopsis species were ...described; however, in 2013, three additional Escovopsis species were formally described along with the genus Escovopsioides, both found exclusively in attine ant gardens. During a survey for Escovopsis species in gardens of the lower attine ant Mycetophylax morschi in Brazil, we found four strains belonging to the pink-colored Escovopsis clade. Careful examination of these strains revealed significant morphological differences when compared to previously described species of Escovopsis and Escovopsioides. Based on the type of conidiogenesis (sympodial), as well as morphology of conidiogenous cells (percurrent), non-vesiculated conidiophores, and DNA sequences, we describe the four new strains as a new species, Escovopsis kreiselii sp. nov. Phylogenetic analyses using three nuclear markers (Large subunit RNA; translation elongation factor 1-alpha; and internal transcribed spacer) from the new strains as well as available sequences in public databases confirmed that all known fungi infecting attine ant gardens comprise a monophyletic group within the Hypocreaceae family, with very diverse morphological characteristics. Specifically, Escovopsis kreiselii is likely associated with gardens of lower-attine ants and its pathogenicity remains uncertain.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Health and disease emerge from intricate interactions between genotypes, phenotypes, and environmental features. The outcomes of such interactions are context-dependent, existing as a dynamic ...continuum ranging from benefits to damage. In host-microbial interactions, both the host and environmental conditions modulate the pathogenic potential of a microorganism. Microbial interactions are the core of the agricultural systems of ants in the subtribe Attina, which cultivate basidiomycete fungi for food. The fungiculture environment harbors a diverse microbial community, including fungi in the genus
Escovopsis
that has been studied as damage-causing agent. Here, we consider the ant colony as a host and investigate to what extent its health impacts the dynamics and outcomes of host-
Escovopsis
interactions. We found that different ant fungal cultivars vary in susceptibility to the same
Escovopsis
strains in plate-assays interactions. In subcolony-
Escovopsis
interactions, while healthy subcolonies gradually recover from infection with different concentrations of
Escovopsis
conidia, insecticide-treated subcolonies evidenced traits of infection and died within 7 days. The opportunistic nature of
Escovopsis
infections indicates that diseases in attine fungiculture are a consequence of host susceptibility, rather than the effect of a single microbial agent. By addressing the host susceptibility as a major modulator of
Escovopsis
pathogenesis, our findings expand the understanding of disease dynamics within attine colonies.
Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in ...peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46μmolmL−1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02μmolmL−1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.
Isolation and screening of new fungal strains from extreme and understudied environments, such as caves, is a promising approach to find higher yields enzyme producers. Cellulolytic fungal strains ...isolated from a Brazilian cave were evaluated for their enzymatic production after submerged (SmF) and solid-state fermentation (SSF). After SmF, three strains were selected for their high enzymatic activities: Aspergillus ustus for endoglucanase (4.76 U/mg), Talaromyces bruneus for β-glucosidase (11.71 U/mg) and Aspergillus sp. (CBMAI 1926) for total cellulase (1.70 U/mg). After SSF, these strains, showed better yields compared to the reference strain Aspergillus niger 3T5B8. Aspergillus sp. (CBMAI 1926) stood out as a new species that expressed activity of total cellulases (0.10 U/mg) and low protein concentration (0.44 mg/mL). In conclusion, these isolated strains have a more efficient and promising cellulolytic enzyme complex that can be used in fermentation and saccharification processes with a lower protein concentration and a higher enzymatic activity than the reference strain. Therefore, beside the new genetic material characterized, our study highlights the benefits of cave extreme environments exploitation to find new potentially valuable strains.
Chemical compounds are key to understand symbiotic interactions. In the leafcutter ant-microbe symbiosis a plethora of filamentous fungi continuously gain access the ant colonies through plant ...substrate collected by workers. Many filamentous fungi are considered transient in attine ant colonies, however, their real ecological role in this environment still remains unclear. A possible role of these microorganisms is the antagonism towards
Leucoagaricus gongylophorus
, the mutualistic fungus that serve as food for several leafcutter ant species. Here, we showed the antagonism of filamentous fungi isolated from different sources, and the negative impacts of their metabolites on the growth of the ant-fungal cultivar. Our results demonstrate that the chemical compounds produced by filamentous fungi can harm the mutualistic fungus of leafcutter ants.
The intensive use of pesticides to control pests in agriculture has promoted several issues relating to environment. As chemical pesticides remain controversial, biocontrol agents originating from ...fungi could be an alternative. Among them, we highlight biocontrol agents derived from the fungi genus
, which have been documented in limiting the growth of other phytopathogenic fungus in the roots and leaves of several plant species. An important member of this genus is
, whose biocontrol agents have been used to promote plant growth while also treating soil diseases caused by microorganisms in both greenhouses and outdoor crops. To evaluate the safety of fungal biological agents for human health, tests to detect potentially adverse effects, such as allergenicity, toxicity, infectivity and pathogenicity, are crucial. In addition, identifying possible immunomodulating properties of fungal biocontrol agents merits further investigation. Thus, the aim of this study was to evaluate the effects of
spores in the internalization of
yeast by mice phagocytes, in order to elucidate the cellular and molecular mechanism of this interaction, as a model to understand possible
effects of this fungus. For this, mice were exposed to a fungal spore suspension through-intraperitoneal injection, euthanized and cells from the peripheral blood and peritoneal cavity were collected for functional, quantitative and phenotypic analysis, throughout analysis of membrane receptors gene expression, phagocytosis ability and cells immunophenotyping M1 (CCR7 and CD86) and M2 (CCR2 and CD206). Our analyses showed that phagocytes exposed to fungal spores had reduced phagocytic capacity, as well as a decrease in the quantity of neutrophils and monocytes in the peripheral blood and peritoneal cavity. Moreover, macrophages exposed to
spores did not display the phenotypic profile M1/M2, and had reduced expression of pattern recognition receptors, such as TLR2, dectin-1 and dectin-2, all involved in the first line of defense against clinically important yeasts. Our data could infer that
spores may confer susceptibility to infection by
.
Bacteria can live in a variety of interkingdom communities playing key ecological roles. The microbiome of leaf-cutting attine ant colonies are a remarkable example of such communities, as they ...support ants’ metabolic processes and the maintenance of ant-fungus gardens. Studies on this topic have explored the bacterial community of the whole fungus garden, without discerning bacterial groups associated with the nutrient storage structures (gongylidia) of ant fungal cultivars. Here we studied bacteria isolated from the surface of gongylidia in the cultivars of
Atta sexdens
and
Acromyrmex coronatus
, to assess whether the bacterial community influences the biology of the fungus. A total of 10 bacterial strains were isolated from gongylidia (
Bacillus
sp.,
Lysinibacillus
sp.,
Niallia
sp.,
Staphylococcus
sp.,
Paenibacillus
sp.,
Pantoea
sp.,
Staphylococcus
sp., and one Actinobacteria). Some bacterial isolates increased gongylidia production and fungal biomass while others had inhibitory effects. Eight bacterial strains were confirmed to form biofilm-like structures on the fungal cultivar hyphae. They also showed auxiliary metabolic functions useful for the development of the fungal garden such as phosphate solubilization, siderophore production, cellulose and chitin degradation, and antifungal activity against antagonists of the fungal cultivar. Bacteria-bacteria interaction assays revealed heterogeneous behaviors including synergism and competition, which might contribute to regulate the community structure inside the garden. Our results suggest that bacteria and the ant fungal cultivar interact directly, across a continuum of positive and negative interactions within the community. These complex relationships could ultimately contribute to the stability of the ant-fungus mutualism.
Age control of banana harvesting under Ecuadorean conditions Montoya, J. (Instituto Nacional de Investigaciones Agropecuarias, Guayaquil (Ecuador). Estacion Experimental Boliche); Marriott, J; Quimi, V.H ...
Fruits (1978),
(May 1984), Letnik:
39, Številka:
5
Journal Article
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