The genus Tulasnella often forms mycorrhizas with orchids and has worldwide distribution. Species of this genus are associated with a wide range of orchids, including endangered hosts. Initially, ...species identification relied mostly on morphological features and few cultures were preserved for later phylogenetic comparisons. In this study, a total of 50 Tulasnella isolates were collected from their natural sites in Minas Gerais, Brazil, cultured, and subjected to a phylogenetic analysis based on alignments of sequences of the internal transcribed spacer (ITS) of the nuclear ribosomal DNA. Our results, based on phylogeny, integrated with nucleotide divergence and morphology, revealed the diversity of isolated Tulasnella species, which included four new species, namely, Tulasnella brigadeiroensis, Tulasnella hadrolaeliae, Tulasnella orchidis and Tulasnella zygopetali. The conservation of these species is important due to their association with endangered orchid hosts and endemic features in the Brazilian Atlantic Forest.
Objectives
To examine the synergistic antibacterial activity of violacein and silver nanoparticles (AgNPs) against ATCC bacteria,
Staphylococcus aureus
,
Escherichia coli
and two bacteria isolated ...from bovine mastitis.
Methods
Violacein from
Chromobacterium violaceum
and biogenic AgNPs from
Fusarium oxysporum
were evaluated in antimicrobial tests.
Results
E. coli
isolates were not inhibited by violacein at concentrations up to 400 μM and they showed sensitivity for AgNPs between 62.5 and 250 μM.
Staphylococcus aureus
showed sensitivity to violacein with MIC of 200 μM, and the MIC with AgNPs between 250 μM and 125 μM. It was also tested the association between the two compounds through a concentration gradient and was observed the reduction of the MIC in the combination for both strains.
Conclusion
The bactericidal effect of violacein against
S. aureus
was better when combined with AgNPs (synergistic).
Seasonal variation in the Canastra cheese mycobiota Martin, José Guilherme Prado; Silva, João Marcos Maia; César, Isabel Cristina da Rocha ...
Frontiers in microbiology,
02/2023, Letnik:
13
Journal Article
Recenzirano
Odprti dostop
Canastra cheese is the most well-known artisanal cheese produced in Brazil. Although its production includes a step to remove fungi from the cheese surface, in recent years some cheesemakers have ...preserved the autochthonous fungi grown during ripening due to an interest in the sensory characteristics attributed to these microorganisms. In this work, the mycobiota of artisanal cheeses produced in the Canastra region was characterized based on ITS marker gene analysis. A total of 96 artisanal cheeses from 16 different farms across 9 cities were collected during two different periods (dry and wet seasons). The Canastra cheese mycobiota was significantly impacted by the season, the city of production and the farm but altitude did not affect the fungal community of the cheeses analyzed.
was most abundant in the majority of samples across both seasons. During the wet season,
and
were the next most abundant species, followed by
and
These results highlight the importance of manufacturing practices and seasonality on the fungal composition of Canastra cheeses. These insights are particularly important in light of recent new regulation in Brazil, removing previous obstacles for surface fungi to persist on cheese. These new regulations will allow new approaches to cheese production, and ultimately, novel products.
Five new species, two new varieties and three newly reported taxa belonging to the Meliolaceae were collected in fragments of Atlantic forest from Minas Gerais, Brazil, in association with native ...plants and are described and illustrated herein. The newly described species are Appendiculella eupatorii, Meliola cassiae-ferrugineae, M. mutisiae, M. peruiferae, M. vernaliae. The new varieties are M. garugae var. protii and M. paullinifolii var. rubiginosae. These taxa are reported in Brazil for the first time: Asteridiella cyclopoda, A. entebbeensis var. codiaei and Meliola pazschkeana var. macropoda. We studied other species belonging in Meliolaceae collected on hosts belonging to the Asteraceae, Burseraceae, Euphorbiaceae, Fabaceae (Caesalpinioideae and Papilionoideae) and Sapindaceae in Brazil.
A survey of foliicolous fungi associated with Dimorphandra wilsonii and Dimorphandra mollis (Fabaceae) was conducted in the state of Minas Gerais, Brazil. Dimorphandra wilsonii is a tree species ...native to the Brazilian Cerrado that is listed as critically endangered. Fungi strictly depending on this plant species may be on the verge of co-extinction. Here, results of the pioneering description of this mycobiota are provided to contribute to the neglected field of microfungi conservation. The mycobiota of D. mollis, which is a common species with a broad geographical distribution that co-occurs with D. wilsonii, was examined simultaneously to exclude fungal species occurring on both species from further consideration for conservation because microfungi associated with D. wilsonii should not be regarded as under threat of co-extinction. Fourteen ascomycete fungal species were collected, identified, described and illustrated namely: Byssogene wilsoniae sp. nov., Geastrumia polystigmatis, Janetia dimorphandra-mollis sp. nov., Janetia wilsoniae sp. nov., Johansonia chapadiensis, Microcalliopsis dipterygis, Phillipsiella atra, Piricauda paraguayensis, Pseudocercospora dimorphandrae sp. nov., Pseudocercosporella dimorphandrae sp. nov., Ramichloridiopsis wilsoniae sp. and gen. nov., Stomiopeltis suttoniae, Trichomatomyces byrsonimae and Vesiculohyphomyces cerradensis. Three fungi were exclusively found on D. wilsonii and were regarded as potentially threatened of extinction: B. wilsoniae, J. wilsoniae and R. wilsoniae.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A survey of fungal pathogens associated with cane tibouchina,
Tibouchina herbacea
(Melastomataceae), was conducted in the neotropics, concentrated in south and southeastern Brazil and aimed at ...finding potential biological control agents for this herbaceous invasive weed for introduction into Hawaii. Numerous fungal species were found, including five cercosporoid fungi. Four new taxa are described and illustrated here:
Passalora tibouchinae
,
Pseudocercospora subsynnematosa
,
Pseudocercospora tibouchina
-
herbaceae
and
Pseudocercospora tibouchinicola
. A phylogenetic analysis of the ITS and TEF-1α regions of the three new species of
Pseudocercospora
was conducted and confirmed their separation as distinct taxa as indicated by morphological and cultural features. Additionally,
Cercospora apii
is reported for the first time on
T. herbacea
. Among the species of fungi described in this study, two appear particularly promising for use in a biological control program because they were found to cause severe disease on
T. herbacea
:
Passalora tibouchinae
and
Pseudocercospora subsynnematosa
. Additional tests, including host-specificity screening, will be required in order to confirm this potential.
Recent searches in Brazil for plant pathogens with potential for use as classical biocontrol agents of Macfadyena unguis-cati yielded five fungal species, two previously undescribed. These are ...described herein and preliminary evaluations based on field and laboratory observations
of the diseases with which they are associated are given. These are: Guignardia mangiferae (leaf spots), Meliola herteri (black mildew), Passalora macfadyenae sp. nov. (leaf spots), Pseudocercospora unguis-cati (leaf spots) and Prospodium macfadyenae sp.
nov. (rust). The two newly described species, Pa. macfadyenae and Pr. macfadyenae, are regarded as having the greatest potential for use in classical biological control.
Solanum lycopersicum
is among the most important crops in Brazil. This crop is affected by a large range of fungal diseases that are recognized as major limitations for tomato production. Recently, ...plants grown in a greenhouse in Viçosa, Minas Gerais, Brazil, were found to bear severe blight symptoms. A pycnidial coelomycete was repeatedly found in association with necrotic tissues. The fungus had its morphology recognized as equivalent to that of
Phoma
and related genera. A phylogenetic analysis based on nrDNA (ITS) and partial β-tubulin (TUB) sequences led to the conclusion that the fungus involved was
Phoma destructiva
. Pathogenicity tests showed that, after 5 days, blight symptoms developed on leaves, flowers and stems of plants belonging to thirteen different tomato varieties tested. This fungal species is mostly known for causing post-harvest tomato rot, which is only regarded as a secondary disease in Brazil. This is in disagreement with the observations made in this work. Here, the disease symptoms caused by the fungus were very severe, fully justifying the scientific name of the pathogen. Under favorable environmental conditions, aggressive strains of
P. destructiva
, such as the one isolated in this study, may become significant threats to tomato plantations in Brazil.
A dematiaceous fungus associated with trichomes on leaflets of Dimorphandra mollis was collected during a survey of fungi associated with the genus Dimorphandra (Fabaceae). The host tree is endemic ...to the Brazilian Cerrado. Although widely distributed there, this
plant has been neglected in mycological studies, since no fungus has ever been recorded in association with it. The new fungus produces large alveariform (skep or beehiveshaped), muriform, dictyosporous, distoseptate, verruculose conidia from large, thickened, dark washer-like conidiogenous
loci. Among previously described anamorphic genera, this fungus is somewhat similar to Annellophragmia, Annellosympodia, Briansuttonia, Dictyospiropes, and Veracruzomyces as well as Spiropes dictyosporus but has some significant differences from those taxa.
Hence, the new genus Alveariospora (type species: A. distoseptata sp. nov.) is proposed for this fungus.
A new leaf spot disease was observed on the orchid species Epidendrum secundum in "high altitude grasslands" of Araponga, Minas Gerais State, Brazil. Inoculation tests on healthy plants confirmed the ...pathogenicity of this fungus. Pseudocercospora epidendri
sp. nov., the causal agent of the leaf spot disease of E. secundum, is described, illustrated, and compared with allied Pseudocercospora species on hosts of the family Orchidaceae.
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