Publications by authors named "Paula B Morais"

Four yeast isolates collected from flowers from different ecosystems in Brazil, one from fruit of in Argentina, three from flowers of in Chile and one obtained from the proventriculus of a female bumblebee in Canada were demonstred, by analysis of the sequences of the internal transcribed spacer (ITS) region and D1/D2 domains of the large subunit rRNA gene, to represent two novel species of the genus . These species are described here as f.a, sp.

View Article and Find Full Text PDF

Tropical rainforests and related biomes are found in Asia, Australia, Africa, Central and South America, Mexico, and many Pacific Islands. These biomes encompass less than 20% of Earth's terrestrial area, may contain about 50% of the planet's biodiversity, and are endangered regions vulnerable to deforestation. Tropical rainforests have a great diversity of substrates that can be colonized by yeasts.

View Article and Find Full Text PDF

Microorganisms play an essential role in ecosystem functions. An increasingly used method for conducting functional analyses of a soil microbial community is based on the physiological profile at the community level. This method allows the metabolic capacity of microorganisms to be assessed based on patterns of carbon consumption and derived indices.

View Article and Find Full Text PDF

is a Gram-negative, immobile, aerobic nosocomial opportunistic coccobacillus that causes pneumonia, septicemia, and urinary tract infections in immunosuppressed patients. There are no commercially available alternative antimicrobials, and multi-drug resistance is an urgent concern that requires emergency measures and new therapeutic strategies. This study evaluated a multi-drug-resistant whole-cell vaccine, inactivated and adsorbed on an aluminum hydroxide-chitosan (mAhC) matrix, in an sepsis model in immunosuppressed mice by cyclophosphamide (CY).

View Article and Find Full Text PDF

Purpose: Obesity has increased around the world. Obese individuals need to be better assisted, with special attention given to dental and medical specialties. Among obesity-related complications, the osseointegration of dental implants has raised concerns.

View Article and Find Full Text PDF

Cobalt-chromium (Co-Cr)-based alloys are emerging with important characteristics for use in dentistry, but the knowledge of epigenetic mechanisms in endothelial cells has barely been achieved. In order to address this issue, we have prepared a previously Co-Cr-enriched medium to further treat endothelial cells (HUVEC) for up to 72 h. Our data show there is important involvement with epigenetic machinery.

View Article and Find Full Text PDF

Four isolates of species were recovered from rotting wood collected in two Brazilian Amazonian biomes. The isolates produced unconjugated allantoid asci with a single elongated ascospore with curved ends. Sequence analysis of the ITS-5.

View Article and Find Full Text PDF

Eight yeast isolates with an affinity to the genus were obtained from bromeliads from different locations in Brazil. Although the formation of basidia and basidiocarp were not observed, on the basis of the results of sequence analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene and internal transcribed spacer (ITS) region, we suggest that these isolates represent two novel species of the genus . These yeasts are phylogenetically related to and .

View Article and Find Full Text PDF

Investigations on the fungal community associated with the digestive tract (DT) of insects have provided insights into the diversity of associated microorganisms and their potential roles in the interaction with their hosts. However, most studies have focused on terrestrial insects, with few studies focusing on aquatic insects in Neotropical regions. We studied fungal taxa associated with the DT of larval stages of the aquatic shredders Phylloicus amazonas, P.

View Article and Find Full Text PDF

Four yeast isolates with an affinity to the genus were obtained from beach sand, a marine zoanthid and a tree exudate at different localities in Brazil. Two other isolates with almost identical ITS and D1/D2 sequences of the large subunit rRNA gene were isolated from the small intestine of cattle and a grease trap in Thailand. These isolates represent a novel species phylogenetically related to , , , and .

View Article and Find Full Text PDF

The leaf-cutter ant Acromyrmex balzani is responsible for causing important losses in reforestation areas, crops, and pastures, and is frequently found in the Brazilian savanna (Cerrado). So far, there is no information regarding the yeast communities that occur in their nests. Here, we evaluated the diversity, composition, and structure of yeast communities in both fungus gardens (FG) and external refuse dump (RD) of this ant species (Palmas, Tocantins, northern Brazil).

View Article and Find Full Text PDF

Yeast communities associated with cacti were studied in three ecosystems of Southeast, Central and North Brazil. A total of 473 yeast strains belonging to 72 species were isolated from 190 samples collected. Cactophilic yeast species were prevalent in necrotic tissues, flowers, fruits and insects of cacti collected in Southeast and North Brazil.

View Article and Find Full Text PDF

Ephemeral microbial communities usually undergo priority effect and result in higher diversity with a few representatives of each species. Community structure of yeasts in bromeliad tanks was compared between two rupestrian savanna (Cerrado) areas in Brazil and to yeasts isolated from water holes in the same areas. Water samples were collected from 60 tanks of bromeliads Bromelia karatas and Encholirium sp.

View Article and Find Full Text PDF

Six strains of a novel yeast species were isolated from tree bark collected in the Atlantic Forest and the Amazon Rainforest in Brazil. Analyses of the sequences of D1/D2 domains of the large subunit rRNA gene showed that the strains belong to a species in the genus . The species differed by 5.

View Article and Find Full Text PDF

Twelve strains of a novel yeast species were isolated from rotting wood, mushrooms and fruit samples in Brazil and French Guiana. Analysis of the sequences of the internal transcribed spacer region and the D1/D2 domains of the large subunit rRNA gene showed that the novel species belongs to the Kurtzmaniella clade. The novel species differed from its closest relative, Candida natalensis, by 12 substitutions in the D1/D2 sequences.

View Article and Find Full Text PDF

The study of microbe domestication has witnessed major advances that contribute to a better understanding of the emergence of artificially selected phenotypes and set the foundations of their rational improvement for biotechnology. Several features make Saccharomyces cerevisiae an ideal model for such a study, notably the availability of a catalogue of signatures of artificial selection and the extensive knowledge available on its biological processes. Here, we investigate with population and comparative genomics a set of strains used for cachaça fermentation, a Brazilian beverage based on the fermentation of sugar cane juice.

View Article and Find Full Text PDF

We investigated the yeast species associated with rotting wood samples obtained from Brazilian ecosystems, with a special focus on cellobiose-fermenting species. About 647 yeast strains were isolated from rotting wood samples collected from the areas of Atlantic rainforest, Cerrado, and Amazonian forest. Eighty-six known species and 47 novel species of yeasts were isolated.

View Article and Find Full Text PDF

This research aimed to evaluate the ecological risk of xenobiotics associated with agricultural activities by determining metal contents and biomarker responses using tucunaré (Cichla sp.) as a bioindicator. The work was conducted in the southwest region of the state of Tocantins, in the cities of Lagoa da Confusão and Pium.

View Article and Find Full Text PDF

Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes.

View Article and Find Full Text PDF

Generally, aquatic communities reflect the effects of anthropogenic changes such as deforestation or organic pollution. The Cerrado stands among the most threatened ecosystems by human activities in Brazil. In order to evaluate the ecological integrity of the streams in a preserved watershed in the Northern Cerrado biome corresponding to a mosaic of ecosystems in transition to the Amazonia biome in Brazil, biological metrics related to diversity, structure, and sensitivity of aquatic macroinvertebrates were calculated.

View Article and Find Full Text PDF

Sixteen yeast isolates identified as belonging to the genus Sugiyamaella were studied in relation to D-xylose fermentation, xylitol production, and xylanase activities. The yeasts were recovered from rotting wood and sugarcane bagasse samples in different Brazilian regions. Sequence analyses of the internal transcribed spacer (ITS) region and the D1/D2 domains of large subunit rRNA gene showed that these isolates belong to seven new species.

View Article and Find Full Text PDF

Four strains alternating between yeast and filamentous growth morphologies were isolated from flowers in two regions of Laos. In liquid environment the isolates propagated by budding and developed irregularly shaped pseudohyphae. On solid media, their yeast cells switched to hyphal growth which could return to the yeast phase by developing lateral blastoconidia.

View Article and Find Full Text PDF

The natural biology of Saccharomyces cerevisiae, the best known unicellular model eukaryote, remains poorly documented and understood although recent progress has started to change this situation. Studies carried out recently in the Northern Hemisphere revealed the existence of wild populations associated with oak trees in North America, Asia, and in the Mediterranean region. However, in spite of these advances, the global distribution of natural populations of S.

View Article and Find Full Text PDF