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Four isolates of Spathaspora 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-5.8S region and the D1/D2 domains of the large subunit rRNA gene showed that the isolates represent two different novel Spathaspora species, phylogenetically related to Sp. boniae. Two isolates were obtained from rotting wood collected in two different sites of the Amazonian forest in the state of Pará. The name Spathaspora brunopereirae sp. nov. is proposed to accommodate these isolates. The holotype of Spathaspora brunopereirae sp. nov. is CBS 16119T (MycoBank MB846672). The other two isolates were obtained from a region of transition between the Amazonian forest and the Cerrado ecosystem in the state of Tocantins. The name Spathaspora domphillipsii sp. nov. is proposed for this novel species. The holotype of Spathaspora domphillipsii sp. nov. is CBS 14229T (MycoBank MB846697). Both species are able to convert d-xylose into ethanol and xylitol, a trait with biotechnological applications.

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. Pichia cactophila, Candida sonorensis and species of the Sporopachydermia complex were the most prevalent cactophilic species in Southeast and Central regions. Kodamaea nitidulidarum, Candida restingae and Wickerhamiella cacticola were frequently associated with cactus flowers and fruits. The diversity of yeasts associated with the substrates studied was high. Twenty-one novel species were found. One is described here as Kluyveromyces starmeri sp. nov. based on 21 isolates obtained from necrotic tissues, flowers, fruits and associated insects of the columnar cacti Cereus saddianus, Micranthocereus dolichospermaticus and Pilosocereus arrabidae in two different ecosystems in Brazil. Phylogenetic analyses of sequences encoding the gene of the small subunit (SSU) rRNA gene, the internal transcribed spacer, the 5.8S rRNA gene and the D1/D2 domains of the large subunit (LSU) rRNA showed that the species is related to Kluyveromyces dobzhanskii, Kluyveromyces lactis and Kluyveromyces marxianus. Phylogenomic analyses based on 1264 conserved genes shared among the new species and 19 other members of the Saccharomycetaceae confirmed this phylogenetic relationship. The holotype is K. starmeri sp. nov. CBS 16103T (=UFMG-CM-Y3682T ). The Mycobank number is MB 836817.

Eight yeast isolates with an affinity to the genus Tremella 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 Tremella. These yeasts are phylogenetically related to Tremella saccharicola and Tremella globispora. Therefore, we propose Tremella ananatis sp. nov. and Tremella lamprococci sp. nov. as novel yeast species of the order Tremellales (Agaricomycotina, Basidiomycota). Sequence analysis revealed that Tremella ananatis sp. nov. differs by 11 and 28 nucleotide substitutions from Tremella saccharicola in the D1/D2 sequence and ITS region, respectively. Moreover, Tremella lamprococci sp. nov. differs by 15 and 29 nucleotide substitutions from Tremella globispora in the D1/D2 sequence and ITS region, respectively. The holotypes of Tremella ananatis sp. nov. and Tremella lamprococci sp. nov. are CBS 14568T and CBS 14567T, and the MycoBank numbers are MB840480 and MB840481, respectively.

We studied the rates of leaf decomposition and loss of leaf constituents (lignin and cellulose) of a native plant species using the litterbag experiment during different seasonal periods (flood and drought) in periodically flooded ecosystems, locally known as “Ipucas”. The effects of flood, edge and fungal colonization on leaf degradation were evaluated. The results show that leaf decomposition is very slow, and influenced by seasonality, flooding and leaf chemical quality. Low moisture and leaf structural components contribute to the slow rate of decomposition. In addition, the fungal biomass was sensitive to the edge effect, with higher values in the center, probably due to the edge losing moisture earlier than the center after the end of rainy season. In addition, the positive correlation of fungal biomass with flooding demonstrates the importance of seasonality in these temporally flooded ecosystems, indicating that global changes in rainfall patterns may disrupt carbon cycling and probably nutrient cycling in periodically flooded environments.

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. and rock holes at the Karstic Area of Aurora, Tocantins State and 60 tanks of Vriesea minarum (Bromeliaceae) and Paepalanthus bromelioides (Eriocaulaceae) at Serra do Cipó National Park, Minas Gerais State in Brazil. The yeast diversity comprised 90 species from which 60% are basidiomycetous yeasts usually associated with phylloplane, soils, and aquatic habitats. The species Papiliotrema laurentii, Rhodotorula mucilaginosa, Pa. nemorosus, and Pseudozyma hubeiensis were the most frequent species associated with bromeliads. Eighteen yeast species, two ascomycetous and 16 basidiomycetous, were consistently isolated from the substrates in both areas and may represent a core community in bromeliads in rupestrian fields. Singlets occurred in 38 to 69% of samples, and 32 species were isolated only once. Our findings reinforce the ephemeral nature of the yeast communities associated with tank-forming plants in which individual phytotelmata act as patches or aquatic islands prone to rapid colonization-extinction rates receiving inocula from plant and soil debris. Ephemeral rock holes also represent a transitory habitat for yeast species associated with plants and soil.

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 Zygotorulaspora. The species differed by 5.54 % sequence divergence (25 substitutions and five indels out of 542 bp) in the D1/D2 sequences from Zygotorulaspora mrakii, its closest relative. The ITS sequence of the type strain of the novel species differs by 27–69 nucleotide substitutions/indels from the other Zygotorulaspora species. The novel species is able to grow on trehalose, maltose, l-sorbose, inulin and at 37 °C, which are negative in Z. mrakii. The name Zygotorulaspora cariocana sp. nov. is proposed. The holotype of Z. cariocana sp. nov. is CBS 16118T. The MycoBank number is MB 833702.

Four yeast isolates with an affinity to the genus Wickerhamiella 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 Wickerhamiella verensis, Wickerhamiella osmotolerans, Wickerhamiella tropicalis, Wickerhamiella sorbophila and Wickerhamiella infanticola. The novel species differs by 15–30 nucleotide differences from these species in the D1/D2 sequences. The name Wickerhamiella martinezcruziae f.a., sp. nov. is proposed. The holotype of Wickerhamiella martinezcruziae sp. nov. is CBS 16104T. The MycoBank number is MB 839328.

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. elektoros and P. fenestratus in the Brazilian Amazon Forest. Filamentous fungi were isolated, purified and screened for cellulolytic activity. A total of 33 fungal taxa was identified through the combination of classical and molecular taxonomy. The genus Penicillium was the most frequent in DT of Phylloicus spp. (18.75%). The occurrence of fungal taxa among hosts was quite variable, with more than half of the associated fungi being exclusive of each host species. A significant portion of the fungal community associated with each host presented cellulolytic activity (± 50%). It was concluded that the fungal community associated with Phylloicus spp. larvae consist mainly of fungal taxa from food items, which come from riparian vegetation (whose plant species are variable) or are indigenous of the aquatic ecosystems, which is the habitat of these larvae.

Made available in DSpace on 2021-06-25T10:56:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 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). A total of 720 yeasts were isolated, comprising 52 species distributed in 29 genera. The RDs have significantly richer and more diverse yeast communities than the fungus gardens, regardless of the season and the level of preservation in the area. The isolates produced a wide range of carbon polymer-degrading enzymes and were able to assimilate carbon-sources present in plant materials. We observed a different proportion of enzyme-producers and carbon-assimilation found in external refuse dump and fungus gardens from preserved and disturbed areas, suggesting that this interaction may vary depending on the environmental conditions. A. balzani nests in the savanna biome are a hotspot of yeast species with ecological, clinical, and biotechnological implications. Centre for the Study of Social Insects São Paulo State University (UNESP) Laboratory of Environmental Microbiology and Biotechnology Federal University of Tocantins (UFT) Department of Pharmaceutical Science School of Pharmaceutical Sciences of Ribeirão Preto University of São Paulo Department of Biology Faculty of Philosophy Sciences and Letters of Ribeirão Preto University of São Paulo Centre for the Study of Social Insects São Paulo State University (UNESP)

Amazon floodplain ecosystems include open water and intermittent flood forest and agricultural systems with different water types. They are a significant natural source of methane (CH4) in the tropics. When soils are flooded and become anoxic, CH4 is produced by methanogenesis, while microbially mediated aerobic and anaerobic oxidation of CH4 serves as the primary biological sink of this greenhouse gas. Measurements of rates and controls on CH4 production and emission in the Amazon basin mainly come from studies on individual wetlands and floodplain lakes. Similarly, microbial communities in those Amazon floodplain habitats have been studied on individual lakes based on sequence-specific DNA analysis. Existing biogeochemical ecosystem models of CH4 from the Amazon floodplains focus on soil properties or involve factors such as pH, redox potentials, or substrates. None of these models incorporate appropriate seasonal inundation; neither the microbiota does it as a component. In this sense, our chapter will highlight how the important efforts already contributed to understand the CH4 emission and its connections with abiotic and biotic factors in Amazon floodplains, as well as emphasize the need of encouraging cooperation and exchange of experience between research teams by using different approaches and scientific methods.

The interaction between insects, both larval and adult, and yeasts associated with their digestive tract (DT), has been of interest in recent years, since it can be beneficial for both partners. Studies focusing on this habitat have contributed to the expansion of knowledge about diversity, biogeography and functional characterization of yeasts, especially in ecosystems still poorly exploited, such as the Brazilian Cerrado. We investigated the interaction between larvae of Phylloicus spp. (Trichoptera: Calamoceratidae), which is an aquatic insect, and the yeasts isolated from its DT. The larvae were collected from first-order Cerrado streams of two States (Mato Grosso – MT and Para – PA) in Brazil. Yeasts were cultivated and identified based on sequence analysis of the D1/D2 domains of the large subunit of rRNA genes. A total of 20 yeast species, belonging to six genera of Ascomycota and five Basidiomycota, is harbored in the DT of the larvae. The most frequent genera were Candida, Papiliotrema, Rhodotorula (19.3% each) and Issatchenkia (15.8%). Candida parapsilosis and Rhodotorula mucilaginosa were only yeast species isolated from the DT of larvae in both locations. The most species-rich community was that associated with DT of Phylloicus spp. in MT samples (H′ = 1.48) as compared to PA samples (H′ = 0.67). All species were accidental (frequency

This work was supported by Fundac¸ão para a Ciência e a Tecnologia (Portugal) grants PTDC/AGR-ALI/118590/2010 and PTDC/BIA-EVF/118618/2010 (J.P.S., P.G.), and UID/ Multi/04378/2013 (A.P., J.P.S., P.G.). This work was supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq—Brazil, process numbers 407415/2013 and 0457499/2014-1, C.A.R.), Fundac¸ão do Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG, process number APQ-01525-14, C.A.R.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. 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. We ask if the selective pressures posed by this fermentation have given rise to a domesticated lineage distinct from the ones already known, like wine, beer, bread, and sake yeasts. Our results show that cachaça yeasts derive from wine yeasts that have undergone an additional round of domestication, which we define as secondary domestication. As a consequence, cachaça strains combine features of wine yeasts, such as the presence of genes relevant for wine fermentation and advantageous gene inactivations, with features of beer yeasts like resistance to the effects of inhibitory compounds present in molasses. For other markers like those related to sulfite resistance and biotin metabolism our analyses revealed distributions more complex than previously reported that support the secondary domestication hypothesis. We propose a multilayered microbe domestication model encompassing not only transitions from wild to primarily domesticated populations, as in the case of wine yeasts, but also secondary domestications like those of cachaça yeasts. authorsversion published

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. Candida boidinii, Cyberlindnera subsufficiens, Meyerozyma guilliermondii, Schwanniomyces polymorphus, Candida natalensis, and Debaryomyces hansenii were the most frequently isolated species. Among the cellobiose-fermenting yeasts, 14 known and three novel yeast species were identified. Scheffersomyces queiroziae, Sc. amazonensis, Yamadazyma sp.1, Hanseniaspora opuntiae, C. jaroonii, and Candida tammaniensis were the main ethanol-producing yeasts. These species also produced an intracellular β-glucosidase responsible for cellobiose hydrolysis. In fermentation assays using a culture medium containing 50 g L−1 cellobiose, ethanol production was observed in all cases; Sc. queiroziae and Sc. amazonensis showed the highest yield, efficiency, and productivity. Candida jaroonii and Yamadazyma sp.1 strains also showed high efficiency in cellobiose fermentation, while C. tammaniensis and H. opuntiae strains produced low amounts of ethanol. This study shows the potential of rotting wood samples from Brazilian ecosystems as a source of yeasts, including new species as well as those with promising biotechnological properties.

A decomposição da matéria orgânica é uma função ecológica que disponibiliza energia para os ecossistemas, sendo desempenhada, em parte, por comunidades fúngicas. O presente estudo teve por objetivo mensurar o percentual de decomposição foliar após 75 dias de incubação em água e solo, além de quantificar as populações e biomassa fúngicas colonizadores dos detritos de duas espécies vegetais, sendo uma nativa de vegetação ripária e uma exótica. Folhas de Cariniana rubra (Jequitibá) nativa na área de estudo, e de Calophyllum brasiliense (Guanandi), que ocorre em ecossistemas de floresta inundada, foram coletadas, secas, armazenadas em litter bags e incubadas em triplicatas por um período de 75 dias, no solo de uma floresta ripária e no fundo de um córrego de primeira ordem. Após a incubação, as folhas foram processadas em laboratório para análises de contagem de unidades formadoras de colônia, quantificação da biomassa fúngica e perda de massa. Os resultados indicam que a contagem de UFC foi maior nas amostras incubadas na água que em solo, mas a riqueza de morfotipos foi maior em solo. A biomassa fúngica diferiu entre folhas incubadas em solo e água para ambas as espécies vegetais, e ambas espécies a taxa de decomposição foi média. Palavras-chave: Biomassa fúngica; contagens de fungos; coeficiente de decomposição; liteira

This research aimed to evaluate the ecological risk of xenobiotics associated with agricultural activities by determining metal contents and biomarker responses using tucunare (Cichla sp.) as a bioindicator. The work was conducted in the southwest region of the state of Tocantins, in the cities of Lagoa da Confusao and Pium. Water samples and specimens of Cichla sp. were collected in the Javaes and Formoso Rivers at three collection points (A, B and C). The concentrations of Cd, Pb, Cu, Cr, Mn, Ni and Zn in water and fish were analyzed. In fish, genotoxic, biochemical (glucose serum levels, AST (aspartate aminotransferase) and ALT (alanine aminotransferase) and histological (gills and liver) biomarkers were assessed. In the water, the Cr and Mn concentrations at the three collection points exceeded the values for Class 1 rivers. In the muscle, Cr was above the maximum limit allowed for human consumption at the three collection points, although the values at Points B and C were not significantly different from that at Point A (p > 0.05). At the three collection points, the micronucleus test revealed a low frequency of micronuclei. Significant hyperglycemia and a decrease in the AST activity of the fish collected at Point C was observed. In the gills, the most frequent alterations were at Stages I and II, which indicated mild to moderate damage, and epithelial detachment was the most frequent variation. In the liver tissue, the most frequently observed histological changes were at Stages I and II and included cytoplasmic vacuolization, nuclear hypertrophy, dilated sinusoids and bile stagnation. The integrated evaluation of these biomarkers indicated that fish collected from areas with intense agricultural activities presented adaptive responses that were likely caused by the availability and bioaccumulation of certain xenobiotics in the environment.

Six novel yeast species, Starmerella camargoi f.a., sp. nov., Starmerella ilheusensis f.a., sp. nov., Starmerella litoralis f.a., Starmerella opuntiae f.a., sp. nov., sp. nov., Starmerella roubikii f.a., sp. nov. and Starmerella vitae f.a, sp. nov. are proposed to accommodate 19 isolates recovered from ephemeral flowers or bees in Brazil, Costa Rica and Belize. Sequence analysis of the ITS-5.8S region (when available) and the D1/D2 domains of the large subunit of the rRNA gene showed that the six novel yeasts are phylogenetically related to several species of the Starmerella clade. The type strains are Starmerella camargoi f.a., sp. nov. UFMG-CM-Y595T (=CBS 14130T; Mycobank number MB 822640), Starmerella ilheusensis f.a., sp. nov. UFMG-CM-Y596T (=CBS CBS14131T; MB 822641), Starmerella litoralis f.a., sp. nov. UFMG-CM-Y603T (=CBS14104T; MB 822642), Starmerella opuntiae f.a., sp. nov. UFMG-CM-Y286T (=CBS 13466T; MB 822643), Starmerella roubikii f.a., sp. nov. UWOPS 01-191.1 (=CBS 15148; MB 822645) and Starmerella vitae f.a., sp. nov. UWOPS 00-107.2 (=CBS 15147T; MB 822646). In addition, 25 species currently assigned to the genus Candida are reassigned formally to the genus Starmerella.

In this study, the chemical composition of the peel and pulp of Mauritia flexuosa fruits were analyzed and the antimicrobial activity of ethanolic extracts from these fruits was evaluated using in vitro tests. Chemical composition analysis with gas chromatography-mass spectrometry (GC-MS) indicated the presence of saturated and unsaturated fatty acids. The peel extracts (ECBU) presented 54.41% and the pulp (EPBU) presented 94.05% of the saturated fatty acids lauric, myristic, palmitic, stearic, oleic and linoleic acids. The antimicrobial activities were performed using the diffusion and micro-dilution (MIC) methods. ECBU was active against the bacteria Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus at a concentration of 200 mg mL-1, but it was not active against the yeasts Candida albicans and Candida parapsilosis using the diffusion method. The MIC results showed that ECBU was active against the tested bacteria at concentrations > 12.5 mg mL-1 and EPBU was active at concentrations > 25.0 mg mL-1. This was probably due to higher sensibility of the method. The results indicated that the peel and pulp extracts of M. flexuosa present antibacterial activity and that ECBU is an especially promising potential candidate for the prospection of new pharmaceutical compounds. Key words: Mauritia flexuosa, Buriti, anti-bacterial agents, fatty acids.

We investigated the distribution patterns of yeast communities in freshwater lakes along a latitudinal gradient in order to evaluate yeast biogeography at intercontinental (501–8000 km), regional (0–500 km) and local (0–1 km) geographical scales. We identified 285 yeast isolates belonging to 64 species based on sequence analysis of the ITS-5.8S region and the D1/D2 domains of the large subunit of rRNA genes. Distance decay analysis showed a significant negative slope curve at the intercontinental scale. At the intercontinental and regional scales, the dissimilarity of the yeast communities was correlated with geographical distance, with community similarity decreasing with increasing distance. The physiological profiles of the yeast communities from tropical and Patagonian lakes were similar but were different from those of Antarctic lakes. This is the first report of latitudinal patterns of lake yeast diversity along a gradient extending from Antarctic to tropical environments. Fil: Brandão, Luciana R.. Universidade Federal de Minas Gerais; Brasil Fil: Vaz, Aline B.M.. Universidade Federal de Minas Gerais; Brasil Fil: Espírito Santo, Lilia C.. Universidade Federal de Minas Gerais; Brasil Fil: Pimenta, Raphael S.. Universidade Federal do Tocantins; Brasil Fil: Morais, Paula B.. Universidade Federal do Tocantins; Brasil Fil: Libkind Frati, Diego. Universidad Nacional del Comahue. Centro Regional Universidad de Bariloche. Departamento de Biología. Laboratorio de Microbiología Aplicada y Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Rosa, Luiz H.. Universidade Federal de Minas Gerais; Brasil Fil: Rosa, Carlos A.. Universidade Federal de Minas Gerais; Brasil

In the middle of a political and fiscal crisis, the Brazilian government is applying successive budget cuts, including in science funding. Recent cuts radically affect research programs on biodiversity that are crucial components for the design and monitoring of public policies for nature conservation and sustainable development. We analyze the consequences of such cuts on the Research Program on Biodiversity (PPBio), the largest biodiversity research network in Brazil (626 researchers, nine networks in all Brazilian biomes). Brazil holds a substantial part of the world's biodiversity and of tropical forests that play a significant role for regional and global climate stability. If underfunding is maintained, the dismantling of the Brazilian PPBio will have consequences that go beyond biodiversity knowledge itself but affect society as a whole. Brazil will likely fail to reach the National Targets for Biodiversity 2011–2020, and it will be difficult to fulfill the restoration target of the Brazilian NDC and to advance with the sustainable development goals. © 2017 Associação Brasileira de Ciência Ecológica e Conservação

Flooded ecosystems are conditioned to seasonal floods that promote specific soil conditions, such as low oxygen, hydromorphism, and peculiar chemical reactions. These environments are dependent on flood pulses that determine specific ecological conditions. Ipucas are seasonally flooded discontinuous forest patches that occur exclusively in the Araguaia Plain in Central Brazil. They are located 0.40 to 1.20 m lower than the surrounding plain, which promotes an accumulation of rainwater for five to six months of the year, being entirely or partially dry during the dry season. The aim of this study was to evaluate the horizontal (centre and edge) and vertical (depths: 0–0.20 m and 0.20–0.40 m) variability of physicochemical parameters in Ipucas soils, attempting to establish the importance of flood pulses and the leaching of surrounding areas in soil formation and composition. Samples were collected during the dry season in three Ipucas of similar size and circularity using a Dutch auger. The results reveal that flood pulses promote the deposition of sediments eroded from the surrounding plain, homogenizing the characteristics of the surface soil, from the edge to the centre of the Ipucas. However, biogeochemical processes, also linked to temporary flooding, account for the differences between the surface and deeper soil horizons because anoxic conditions during flooding promote chemical reactions characteristic of anaerobic environments, modifying the pH and organic matter content, in addition to the gleying of soils subjected to flooding, which are then covered by sediments after the dry season. Finally, Ipucas soils are susceptible to anthropic changes and are dependent on seasonal flood pulses.

Microbial lipases are prominent biocatalysts able to catalyze a wide variety of reactions in aqueous and nonaqueous media. In this work, filamentous fungi isolated from leaves decomposed in an aquatic environment were screened for lipase production with hydrolytic activity and esterification. Agar plates with Tween 20 and Rhodamine B were used for selection, while submerged cultures with olive oil were subsequently used to select 38 filamentous fungi. Trichoderma harzianum, Fusarium solani, Trichoderma harzianum F5, and Penicillium sp. F36 were grown in six different culture media. F. solani presented the highest lipase production (2.37 U/mL) with esterification activity of 0.07 U/mL using medium composed of (g.L−1) KH2PO4 1.00, MgSO4 H2O 1.123, and CuSO4 0.06. Supplementation of this culture medium with organic nitrogen sources increased lipase production by 461.3% using tryptone and by 419.4% using yeast extract. Among the vegetable oils from the Amazon region, degummed cotton oil induced lipase production up to 8.14 U/mL. The lipase produced by F. solani F61 has great potential to application in conventional processes and biodiesel production by transesterification of vegetable oils, as well as food industries in the production of fatty acid esters by hydrolysis and esterification.

International audience; 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. The novel species could be distinguished from C. natalensis by its inability to assimilate cellobiose and salicin, and growth at 50 % (w/w) glucose. The name Kurtzmaniella hittingeri f.a., sp. nov. is proposed for the novel species. The type strain of K. hittingeri sp. nov. is CBS 13469(T) (=UFMG CM-Y272(T)). The MycoBank number is 827183. We also propose the transfer of Candida fragi, Candida quercitrusa and Candida natalensis to the genus Kurtzmaniella as new combinations.

This work was supported by Fundacao para a Ciencia e a Tecnologia, Portugal, grants PTDC/BIA-EVF/118618/2010 (J.P.S., P.A., P.G.), PTDC/AGR-ALI/118590/2010 (J.P.S., P.A., P.G., R.B.), UID/Multi/04378/2013 (J.P.S., P.G.), and SFRH/BD/77390/2011 (P.A.), by Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq (CAR, process numbers 560715/2010-2 and 457499/2014-1, PBM process number 457443/2012-0) and Fundacao de Amparo a Pesquisa de Minas Gerais FAPEMIG and VALE S.A (CAR, process number RCP-00094-10). Work of C.R.L. on this project was supported by a NSERC Discovery grant. C.R.L. holds the Canada Research Chair in Evolutionary Cell and Systems Biology. The authors thank Dr. Siu Mui Tsai, Universidade de Sao Paulo, Brazil, for making available strain UFMG-CM-Y640. 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. cerevisiae, especially in regions were oaks and other members of the Fagaceae are absent, is not well understood. Here we investigate the occurrence of S. cerevisiae in Brazil, atropical region where oaks and other Fagaceae are absent. We report a candidate natural habitat of S. cerevisiae in South America and, using whole-genome data, we uncover new lineages that appear to have as closest relatives the wild populations found in North America and Japan. A population structure analysis revealed the penetration of the wine genotype into the wild Brazilian population, a first observation of the impact of domesticated microbe lineages on the genetic structure of wild populations. Unexpectedly, the Brazilian population shows conspicuous evidence of hybridization with an American population of Saccharomyces paradoxus. Introgressions from S. paradoxus were significantly enriched in genes encoding secondary active transmembrane transporters. We hypothesize that hybridization in tropical wild lineages may have facilitated the habitat transition accompanying the colonization of the tropical ecosystem. publishersversion published

Babaçu (A. speciosa), Buriti (M. flexuosa), and Macaúba (A. aculeata) are palm trees typical of the ecotone area between Cerrado and the Amazon rainforest. The purpose of this study was to evaluate the antimicrobial potential of the extracts prepared from the leaves of those palms as well as determine their chemical compositions. The ethanol extracts were prepared in a Soxhlet apparatus and tested by disk diffusion and agar dilution technique againstStaphylococcus aureus,Enterococcus faecalis,Escherichia coli, Pseudomonas aeruginosa,Candida albicans, andCandida parapsilosis.However, there was no significant activity at concentrations of 25, 50, and 100 mg·Ml−1. Moreover, the phytochemical analysis revealed the presence of tannins, flavonoids, catechins, steroids, triterpenes, and saponins. Gas chromatography (GC/MS) analysis also identified organic acids, such as capric (decanoic) acid, lauric (dodecanoic) acid, myristic (tetradecanoic) acid, phthalic (1,2-benzenedicarboxylic) acid, palmitic (hexadecanoic) acid, stearic (octadecanoic) acid, linoleic (9,12-octadecadienoic) acid (omega-6), linolenic (octadecatrienoic) acid (omega-3), and the terpenes citronellol and phytol. Based on the chemical composition in the palm leaf extracts, the palms have the potential to be useful in the food, cosmetic, and pharmaceutical industries.

O uso do solo com cultivos anuais durante longo tempo, especialmente quando são utilizados manejos não conservacionistas, como arações e gradagens, normalmente são responsáveis pela degradação mais intensa de suas propriedades. Este trabalho avaliou as propriedades do solo em três áreas sob cultivo agrícola e uma área nativa de Cerrado, verificando as alterações ocorridas nos atributos físico-químicos do solo após dois, cinco e oito anos sob plantio de soja. As amostras de solo foram coletadas na Fazenda Praia Alta, no município de Lagoa da Confusão - TO, onde a soja é cultivada no período de entressafra (maio-junho), em várzea irrigada, sob regime de subirrigação. A análise físico-química do solo quantificou pH, matéria orgânica (MO), P, S, K, Ca, Mg, Al, H + Al, CTC, SB, Na, Zn, B, Cu, Fe, Mn, argila, silte e areia. Os resultados mostraram evidências que o tempo de uso do solo com agricultura tecnificada, influencia as propriedades do solo; o tempo de cultivo do solo parece influenciar as modificações nos atributos naturais de áreas de várzea alagável no Cerrado. Palavras-chave: nutrientes, propriedades do solo, plantio direto. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v5n4p56-62

Attalea speciosa Mart ex Spreng is a oil palm belonging to the family Arecaceae with fruits 15% of the total weight of the fruit correspond to the epicarp; 20% to 58% to the mesocarp and endocarp (including almonds), the almonds being its most used component. Fruits are important natural microhabitats for a significant diversity of yeast species. The objective of this study was to isolate and test the enzymatic abilities of yeast strains associated with almond fruits of Attalea speciosa, and their possible biotechnological potential for industrial purposes. Ten collections of 15 almonds for sample were conducted at seven days intervals at an extractivism reserve of Mata de Babacuais ecosystem. Among 84 yeasts isolated, The enzymatic activity was evaluated and among the eighty-four strains of yeast tested as the ability to hydrolyze casein among protease, 26.04% had enzymatic potential acidic pH, 31.92% at neutral pH and 28.56% in alkaline pH, demonstrating enzyme potential in different pHs.A lipase activity was also satisfactory where, sixty-two lipase producing strains may have potential use for commercial employment testing microbial lipases. Already cellulolytic activity was more limited, only nineteen lineages showed degrading cellulose.

O reservatório da UHE Lajeado-TO localiza-se na região central do estado do Tocantins e possui condições propícias a atividades de lazer. Suas margens apresentam um elevado potencial recreacional, portanto, as condições sanitárias necessárias às atividades de contato primário devem ser asseguradas à população. Indicadores de balneabilidade devem ser avaliados em ambientes com fins recreacionais com o objetivo de prever e evitar efeitos adversos à saúde humana e à biota aquática. O presente trabalho realizou a avaliação do parâmetro indicador de contaminação fecal, Escherichia coli, para a classificação da balneabilidade em quatro praias na capital do Estado do Tocantins, Palmas. São elas as Praias do: Caju, Prata, Graciosa e das Arnos. Para tal, foram realizadas a detecção e contagens de Escherichia coli pela técnica do substrato cromogênico, de amostras coletas em cinco semanas, entre os anos de 2012 e 2015. As águas apresentaram baixas contagens de Escherichia coli, que permitiram a classificação como muito boa ou excelente balneabilidade, conforme a Resolução CONAMA Nº 274/2000. Dessa forma, o trabalho contribui para assegurar as atividades de lazer com segurança, e construir um banco de dados importante sobre as condições microbiológicas das praias pertencentes ao reservatório.

Ipucas são ecossistemas de fragmentos florestais naturais, ocorrendo particularmente na planície do Araguaia. Apresenta grande influência dos pulsos de inundação que ocorrem no período chuvoso, pois permanecem inundadas durante este período e como ambientes terrestres no período seco. O estudo objetivou avaliar a variação temporal de fatores limnológicos em uma Ipuca, no município de Lagoa da Confusão, Tocantins, através de coletas mensais entre Dezembro/2014 e Agosto/2015. As variáveis mensuradas foram: transparência através do disco Secchi, turbidez (NTU), oxigênio dissolvido (mg/L), temperatura (°C), potencial hidrogeniônico - pH, sólidos totais dissolvidos (ppm), condutividade elétrica (µS/cm), amônia – NH3 (mg/L), nitrito – NO­2 (mg/L), nitrato – NO3 (mg/L), ortofosfato - P (mg/L), clorofila-? (µg/L) e profundidade da lamina d’água (cm). O total transparência da água e os baixos valores de turbidez demonstram a importância da precipitação nestes parâmetros, assim como a estrutura florestal da “Ipuca” suporta os valores encontrados. A temperatura da água das “Ipucas” foi influenciada pelas estações do ano, principalmente pela quantidade de ventos. O oxigênio dissolvido esteve diretamente relacionado a clorofila-?. A concentração dos nutrientes analisados apresentou grandes oscilações, provavelmente devido à rápida incorporação destes pelas comunidades aquáticas. Contudo, foi observada uma homogeneização dos parâmetros físico-químicos no decorrer do tempo amostral.

O processo de decomposição da matéria orgânica em córregos de baixa ordem, realizado em grande parte pelos fungos, é importante para o fornecimento de energia a diversos níveis tróficos neste ecossistema. O presente trabalho avaliou a variação temporal de bolores e leveduras associados ao processo de decomposição foliar em um córrego de baixa ordem no cerrado tocantinense. Detrito vegetal misto foi coletado do aporte vertical da vegetação ripária e colocado em sacos de malha grossa e submersos por 30 dias no córrego Buritizal. O isolamento e contagem dos fungos filamentosos e leveduras foi realizado a partir do macerado de discos foliares em caldo peptonado e semeado em placas de petri contendo meio BDA e YMA incubados por 30 dias. As contagens de leveduras variaram de 1,42 logUFC.gMOF em junho de 2011 a 5,90 logUFC.gMOF em abril de 2012. Os fungos filamentosos variaram de 1,98 logUFC.gMOF em julho de 2011 a 6,27 logUFC.gMOF em março de 2013. As maiores contagens de fungos filamentosos e leveduras ocorreram em ambos períodos chuvosos porém somente os filamentosos apresentam diferença estatisticamente significativa e podem estar associadas as enxurradas, quando há o escoamento da serrapilheira e solo das margens com consequente maior entrada de geofungos e demais sapróbios associados ao aporte horizontal.

As celulases e xilanases fúngicas, derivadas de sua habilidade degradativa e excretadas, em geral, para o meio, despertam interesse biotecnológico por terem um largo espectro de aplicação. Objetivou-se verificar a produção das enzimas celulase e xilanase por fungos filamentosos isolados de detritos foliares alóctone em um córrego no Cerrado. Os testes foram realizados com 100 cepas utilizando meio de cultura sintético contendo, como única fonte de carbono, carboximetilcelulose e xilana, para celulase e xilanase, respectivamente. Foram realizados inóculos no centro das placas e armazenadas por 4 dias em BOD a 28°C e submetido a choque térmico em estufa a 50°C por 16 horas. Para melhor visualização do halo de hidrólise as placas foram coradas com solução de vermelho congo e lavadas com solução de NaCl. Dos fungos testados 69% apresentaram resultado positivo para celulase dos quais 23% foram consideramos com potencial para aplicação em biotecnologia. Não houve resultados positivos para a produção da enzima xilanase. Os fungos testados, associados ao processo de decomposição de matéria orgânica vegetal, apresentaram produção da enzima celulase, mas não da enzima xilanase.

As cianobactérias são componentes naturais do fitoplâncton e têm recebido uma atenção da comunidade científica e dos órgãos ambientais por desenvolverem florações em ambientes com condições eutróficas. O Índice de Estado Trófico (IET) é um diagnóstico da saúde do corpo hídrico em relação ao seu grau de trofia. Este trabalho teve como objetivo avaliar a qualidade da água no reservatório da PCH Porto Franco através da abundância relativa de Cyanobacteria e o IET. Foram realizadas 19 coletas no período de 2009 a 2014 onde se avaliou em quatro pontos amostrais a comunidade fitoplanctônica, fósforo e clorofila a. As cianobactérias ocorreram em todos os pontos monitorados e foram representadas por vários táxons potencialmente tóxicos, como Cylindrospermopsis raciborski e Planktolyngbya limnetica. Esses organismos são potencialmente tóxicos e podem provocar danos à saúde humana e ao ambiente. A dominância de Cyanobacteria está associada às condições mesotróficas a supereutróficas que ocorreram principalmente no ponto a montante barramento. O predomínio do ambiente lêntico, disponibilidade de radiação subaquática, bem como a alta concentração de nutrientes demonstrados pelo IET são condições que determinam o expressivo desenvolvimento de Cyanobacteria neste reservatório

O presente trabalho teve como objetivo testar um protocolo de avaliação rápida (PAR) para avaliação da microbacia do Córrego Sussuapara, um córrego urbano em Palmas, Tocantins. A integridade de ecossistemas aquáticos em áreas urbanas é ameaçada pelas atividades humanas em sua bacia. Assim, PAR podem ser ferramentas auxiliares ao monitoramento microbiológico e físico-químico das águas. O protocolo elaborado teve como atributos os parâmetros substrato de fundo, complexidade do habitat, qualidade dos remansos, velocidade da corrente, proteção e estabilidade dos barrancos, cobertura vegetal das margens, extensão da mata ciliar e ação antrópica, para os quais foram atribuídos uma entre quatro qualificações conforme a percepção das pessoas envolvidas. Dois grupos de aplicadores foram selecionados, estudantes de graduação do curso de Engenharia Ambiental da Universidade Federal do Tocantins e professores do ensino fundamental do município, com diferentes formações em ensino superior. O resultado foi comparado com o monitoramento físico-quimico e microbiológico. O protocolo aplicado mostrou-se de fácil entendimento e rápida aplicação por ambos os grupos, mostrando resultados similares da avaliação da integridade ambiental de um trecho do Córrego Sussuapara, situado em área urbana de Palmas. A avaliação feita pelos dois grupos refletiu os impactos resultantes das falhas da drenagem urbana de Palmas sobre o córrego, refletido na baixa qualidade do substrato de fundo, na qualidade da proteção e estabilidade dos barrancos e no grau de atividade antrópica, atributos com classificação razoável e ruim pelos atores envolvidos.

In Brazilian savannas, stingless bees are associated with yeast communities composed mainly of Starmerella species. This study aimed to establish the distribution of yeasts associated with the bee species Frieseomelitta varia, Scaptotrigona aff. postica, Scaptotrigona polysticta, Tetragonisca angustula angustula, Melipona compressipes manaosensis and Melipona scutellaris in northern savannas and the importance of yeasts in the resource partitioning of bees. We collected 380 bees from six species, which were individually placed in Petri plates containing rich medium for 15 min. Yeasts were then isolated, resulting in the identification of 54 species, 48 of which were ascomycetous, while six were basidiomycetous. Torulaspora delbrueckii was the most frequently isolated yeast species in this study, followed by Pichia membranifaciens, Starmerella apicola, Pichia kluyveri, Starmerella meliponinorum and Starmerella bombicola. The total number of Starmerella species identified showed that these species are prevalent in association with these stingless bees. These communities differ from stingless bee-associated yeasts found in the southern savannas of Brazil. Although stingless bees are generalist foragers, there are some yeasts showing high prevalence in only one bee species, resulting in differences in niche breadth that may point to a role of yeasts in the resource partitioning of bees in Brazilian savannas.

Macroinvertebrate shredders consume preferably leaves conditioned by fungi and bacteria which offer greater palatability to them. Plant species in Cerrado present high concentration of chemical elements such as lignin and cellulose, phenols and tanins thus making them less attractive for shredders consumption and limiting the palatability. This study aimed to evaluate the feeding preference of a macroinvertebrate shredder of the genus Phylloicus for plant material from two different biomes (Cerrado and Mata Atlântica), after conditioning in a stream of Mata Atlântica and observing their physical and chemical characteristics. Senescent leaves were collected, monthly from the litterfall of riparian vegetation in a 500 m stretch of a stream in each biome from August 2014 to January 201. The most abundant species in each stream was selected for the experiment. The experimental design consisted in with two treatments. The first (T1) comprised leaf discs from Chrysophyllum oliviforme (Cerrado species) together with leaf discs of Miconia chartacea (Atlantic Forest species) which were conditioned in the Atlantic Forest stream. The second treatment (T2) involved leaf discs of Miconia chartacea conditioned in Mata Altlântica and Cerrado streams. Both tests had showed significant differences between the two treatments (T1 and T2). For T1, there was consumption of M. chartacea leaf discs by Phylloicus sp., but there was no consumption of C. oliviforme discs. For T2, there was preference for M. chartaceae leaves conditioned in a stream of Mata Atlântica than in Cerrado stream. The results showed that Phylloicus sp., had presented preference for food detritus of the Mata Antlântica biome and rejection to the one from Cerrado biome. Resumo Macroinvertebrados fragmentadores consomem folhas preferencialmente condicionadas por fungos e bactérias que lhes oferece uma maior palatabilidade. Nas espécies do cerrado esse condicionamento está também associado às altas concentrações de elementos químicos limitantes à palatabilidade como alto teor de lignina e celulose, que tornam as folhas menos atrativas para os fragmentadores. O trabalho teve como objetivo avaliar a preferência alimentar de macroinvertebrados fragmentador ( Phylloicus sp.) por material vegetal de dois diferentes biomas (Cerrado e Mata Atlântica), após condicionamento em riacho de Mata Atlântica, observando suas características físicas e químicas. Foram coletadas folhas senescentes do aporte vegetal (AV) de espécies nativas da vegetação ripária nesses dois biomas, com periodicidade mensal em um trecho de 500 m de um córrego em cada bioma. O experimento foi delineado com dois tratamentos. O primeiro (T1) compreendeu discos de folhas do Cerrado (Chrysophyllum oliviforme) mais discos de folhas da Mata Atlântica (Miconia chartacea) que foram condicionadas em córrego de Mata Atlântica. O segundo tratamento (T2) envolveu discos de folhas da Mata Atlântica condicionadas em córrego da Mata Atlântica mais discos de folhas da Mata Atlântica condicionadas em córrego do Cerrado. Os dois testes apontaram diferenças significativas entre os dois tratamentos (T1 e T2). Para T1 houve consumo de discos de folha de M. chartacea por Phylloicus sp, mas não houve consumo dos discos de C. oliviforme , de Cerrado. Para T2, houve o consumo, porém a preferência pelas folhas de M. chartaceae condicionadas no córrego da Mata Atlantica foi consideravelmete maior. Os resultados apontam que Phylloicus sp, apresentou preferência alimentar pelo detrito de bioma de Mata Atlântica e rejeição pelo detrito do bioma Cerrado.

Forest-to-agriculture conversion and soil management practices for soybean cropping are frequently performed in the Cerrado (Brazilian tropical savanna). However, the effects of these practices on the soil microbial communities are still unknown. We evaluated and compared the fungal community structure in soil from soybean cropland with soil under native Cerrado vegetation at different times of the year in the Tocantins State. Soil samples were collected in two periods after planting (December) and in two periods during the soybean reproductive growth stage (February). Concomitantly, soil samples were collected from an area under native Cerrado vegetation surrounding the agricultural area. The soil DNA was analyzed using a fingerprinting method termed Automated Ribosomal Intergenic Space Analysis (ARISA) to assess the fungal community structure in the soil. Differences in the fungal community structure in the soil were found when comparing soybean cropland with the native vegetation (R = 0.932 for sampling 1 and R = 0.641 for sampling 2). Changes in the fungal community structure after management practices for soybean planting in Cerrado areas were related to changes in soil properties, mainly in copper, calcium, and iron contents, cation exchange capacity, base saturation, and calcium to magnesium ratio. These results show the changes in the fungal community structure in the soil as an effect of agricultural soil management in Cerrado vegetation in the state of Tocantins.

A existência de diversos reservatórios de usinas hidrelétricas no Brasil apresenta a possibilidade da utilização destes recursos hídricos para a criação de peixes em sistema de tanques-rede, o que contempla a ideia de uso múltiplo dos recursos hídricos. Esse sistema de produção enriquece o ambiente aquático com nutrientes, principalmente o nitrogênio e fósforo, oriundos dos dejetos do metabolismo do alimento e com eventuais sobras de alimentos pelos peixes. A emissão desses nutrientes em níveis acima do limite que o sistema é capaz de metabolizar pode provocar o fenômeno da eutrofização, comprometendo a qualidade da água para os seus usos múltiplos. Este estudo avaliou as condições limnológicas do reservatório da UHE Luis Eduardo Magalhães na influência do cultivo de peixes em tanques-rede, através da análise das alterações dos parâmetros físicos e químicos da água, comparando-os com a Resolução CONAMA 357/05. As amostras para as análises foram obtidas bimestralmente durante um ano, em cinco pontos distribuídos na região onde foi instalado o sistema de cultivo. Os resultados demonstram tanto variações temporais, quanto espaciais, estando dentro dos valores normais indicados pelo CONAMA. A exceção foi o fósforo total, que chegou a apresentar concentrações 10 vezes acima do recomendado pela Resolução. Observou-se que este nutriente não foi limitante, pois o reservatório apresenta esta característica. Assim, para que essa atividade se desenvolva de forma sustentável, é necessário avaliar as condições limnológicas do ambiente na qual estão inseridas.

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. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m−2 y−1, storage: 55, 113 and 38 g m−2, on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas.

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. Sampling included collections along stretches of 200 m of nine streams and measurements of abiotic variables (temperature, electrical conductivity, pH, total dissolved solids, dissolved oxygen, and discharge) and the Index of Habitat Integrity (HII). The values of the abiotic variables and the HII indicated that most of the streams have good ecological integrity, due to high oxygen levels and low concentrations of dissolved solids and electric conductivity. Two streams showed altered HII scores mainly related to small dams for recreational and domestic use, use of Cerrado natural pasture for cattle raising, and spot deforestation in bathing areas. However, this finding is not reflected in the biological metrics that were used. Considering all nine streams, only two showed satisfactory ecological quality (measured by Biological Monitoring Working Party (BMWP), total richness, and EPT (Ephemeroptera, Plecoptera, and Trichoptera) richness), only one of which had a low HII score. These results indicate that punctual measures of abiotic parameters do not reveal the long-term impacts of anthropic activities in these streams, including related fire management of pasture that annually alters the vegetation matrix and may act as a disturbance for the macroinvertebrate communities. Due to this, biomonitoring of low order streams in Cerrado ecosystems of the Northern Central Brazil by different biotic metrics and also physical attributes of the riparian zone such as HII is recommended for the monitoring and control of anthropic impacts on aquatic communities.

Yeast communities associated with necrotic tissues of cacti and ripe tropical fruits are excellent models for studying the ecology and evolution of these fungi. The availability of carbon sources, chemistry of the substrate, presence of antimicrobial compounds, mutualisms with insect vectors, competition, predation, and habitat heterogeneity in space and time all influence cactophilic yeast occurrence. Four yeast species are prevalent in necrotic cactus tissues: Pichia cactophila, Candida (Ogataea) sonorensis, Clavispora opuntiae, and Sporopachydermia cereana species complex. Other species are limited to determined geographic areas or host plants. Species isolated only from necrotic cactus tissues are considered as cactophilic and are vectored by insects that feed and breed in these substrates, mainly Drosophila spp. Ripe fruit yeast communities are composed mainly of species with a limited physiological nutritional profile during the early stages of fruit deterioration. Ascomycetous yeast species are most frequently associated with ripe fruits, such as Hanseniaspora uvarum, Pichia kudriavzevii, Meyerozyma guilliermondii, Aureobasidium pullulans, Wickerhamiella spp., and others. Basidiomycetous species occur mainly in the later stages of fruit deterioration. Necrotic cactus tissues and ripe tropical fruits also represent rich sources for the discovery of new yeast species.

A novel yeast species was recovered from the fungus garden of the leaf-cutting ant Acromyrmex balzani (Hymenoptera: Formicidae). The growth of the novel yeast species is limited by its ability to metabolize only a few carbon and nitrogenous compounds. A remarkable characteristic of this strain is the vigorous growth in 1 % acetic acid. Sequence analysis of the D1/D2 domains of the LSU rRNA gene showed that the novel species belongs to the Starmerella clade and is phenotypically and genetically divergent from currently recognized species in this clade. Described here as Starmerella aceti f.a., sp. nov., it differs by 37 nucleotide substitutions in the D1/D2 region from Starmerella jinningensis CBS 11864T, the most closely related species. The type strain of Starmerella aceti sp. nov. is TO 125T ( = CBMAI 1594T = CBS 13086T).

The aim of this work was to study the yeast populations and the main hygienic-sanitary microbial indicators in water buffalo mozzarella produced and commercialized in Minas Gerais, Brazil. Forty-two water buffalo mozzarella samples were purchased from retail outlets in Belo Horizonte. In addition, five samples of consecutive starter cultures, curd before acidification, acidified curd and mozzarella were collected at an industry in the city of Oliveira. Only three of the five water samples analyzed were suitable for consumption according to Brazilian sanitary standards. Four milk samples were highly contaminated with fecal coliforms, and did not meet the minimal hygienic-sanitary standards according to Brazilian regulations. Only one sample of buffalo muzzarela purchased from retail outlets exceeded the limit for coagulase-positive Staphylococcus. Eleven samples showed counts of thermotolerant coliforms higher than 5 × 10(3) CFU.g(-1), but still lower than the maximum permitted by the Brazilian laws. Salmonella spp. and Listeria monocytogenes were not isolated. Debaryomyces hansenii, Candida lusitaniae and C. parapsilosis were the prevalent yeast species isolated from cheese. Among samples from the production stages, the acidified curd presented the highest numbers of yeasts, with C. catenulata being the most frequent species isolated. Some opportunistic yeast species such as C. guilliermondii, C. tropicalis, C. parapsilosis, C. lusitaniae, C. catenulata, C. rugosa and C. krusei occurred in the mozzarella cheese samples analyzed. The mozzarella cheese presented a low microbial load as compared to other cheese already studied, and the yeast biota included species typical of cheese and also opportunistic pathogens.

This work aimed to characterize the microbiota involved in the production of puba flour in Palmas, Brazil, and to verify the presence of aflatoxins in this food product. Counts of mesophilic heterotrophic bacteria, Lactobacillus spp., Streptococcus spp. and yeasts were done by dilution and plating on specific media. The results showed the presence of high populations of all microbial groups screened (>107 CFU g-1). Among lactobacilli, L. plantarum was the most frequent species, representing 41.6 % of total isolates of this genus. The most frequent yeasts were Candida castelli, C. ethanolica, C. krusei, Pichia membranifaciens and Trichosporon asahii. Counts of total and fecal coliforms obtained by the chromogenic Colilert technique were high mainly in samples of fermenting water, above 800 and 2,000 MPN 100 mL-1 respectively. Nevertheless in the final product those numbers were reduced considerably to less than 70 and 1 MPN g-1 respectively, values considered within the legal limits established by regulations. ELISA and thin layer chromatography showed no occurrence of aflatoxins, differently from other studies elsewhere. With this we can to observe that the products analyzed fit the Standards of the Brazilian Ministry of Health.Key words: Manihot esculenta Crantz; fermentation; microorganisms, aflatoxin, puba flour. ResumoEste trabalho teve como objetivo caracterizar a microbiota envolvida na produção de farinha de puba em Palmas, Brasil, e verificar a presença de aflatoxinas neste produto alimentar. Contagens de bactérias heterotróficas mesófilas, Lactobacillus spp., Streptococcus spp. e leveduras foram realizadas por diluição e plaqueamento em meios específicos. Os resultados mostraram a presença de elevados números populacionais de todos os grupos microbianos pesquisados (> 107 UFC g-1). Entre os lactobacilos, L. plantarum foi a espécie mais frequente, representando 41,6% dos isolados totais deste gênero. As leveduras mais frequentes foram Candida castelli, C. ethanolica, C. krusei, Pichia membranifaciens e Trichosporon asahii. As contagens de coliformes totais e fecais obtidas pela técnica Colilert cromogénico foram elevadas, principalmente em amostras de água de fermentação, acima de 800 e 2000 NMP 100 mL-1, respectivamente. No entanto no produto final esses números foram reduzidos consideravelmente a menos de 70 e 1 MPN g-1, respectivamente, valores considerados dentro dos limites legais estabelecidos pelos regulamentos. Não foi observada a presença de aflatoxinas em nenhum dos testes realizados (ELISA e cromatografia em camada delgada), resultados divergentes de outros estudos realizados em outros países. Com isto podemos constatar que os produtos analisados atendem às normas do Ministério da Saúde do Brasil.Palavras chaves: Manihot esculenta Crantz, fermentação, micro-organismos, aflatoxinas, farinha de puba.

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. The species are described here as Sugiyamaella ayubii f.a., sp. nov. (UFMG-CM-Y607T = CBS 14108T), Sugiyamaella bahiana f.a., sp. nov. (UFMG-CM-Y304T = CBS 13474T), Sugiyamaella bonitensis f.a., sp. nov. (UFMG-CM-Y608T = CBS 14270T), Sugiyamaella carassensis f.a., sp. nov. (UFMG-CM-Y606T = CBS 14107T), Sugiyamaella ligni f.a., sp. nov. (UFMG-CM-Y295T = CBS 13482T), Sugiyamaella valenteae f.a., sp. nov. (UFMG-CM-Y609T = CBS 14109T) and Sugiyamaella xylolytica f.a., sp. nov. (UFMG-CM-Y348T = CBS 13493T). Strains of the described species S. boreocaroliniensis, S. lignohabitans, S. novakii and S. xylanicola, isolated from rotting wood of Brazilian ecosystems, were also compared for traits relevant to xylose metabolism. S. valenteae sp. nov., S. xylolytica sp. nov., S. bahiana sp. nov., S. bonitensis sp. nov., S. boreocarolinensis, S. lignohabitans and S. xylanicola were able to ferment d-xylose to ethanol. Xylitol production was observed for all Sugiyamaella species studied, except for S. ayubii sp. nov. All species studied showed xylanolytic activity, with S. xylanicola, S. lignohabitans and S. valenteae sp. nov. having the highest values. Our results suggest these Sugiyamaella species have good potential for biotechnological applications.

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. The sequences of the D1/D2 domains of the large subunit (LSU) 26S rRNA genes, the internal transcribed spacer (ITS) regions and the small subunit (SSU) 18S rRNA genes were identical in the four strains and differed from the corresponding sequences of other yeast species available in databases by at least 11 % (D1/D2), 13 % (ITS) and 7 % (SSU). In an independent project, two strains with D1/D2 and ITS sequences very similar to those of the Laotian strains were found in bark samples collected in Brazil. The six strains also differed from the closest yeast species in physiological properties, indicating that they represented a hitherto undescribed species. Phylogenetic analysis of the D1/D2 sequences, and the concatenated sequences of the SSU rRNA genes, D1/D2 domains of LSU rRNA genes as well as the protein-encoding genes ACT1 and TEF1 placed thestrains close to Hyphopichia. To reflect this position, the novel genus name Metahyphopichia gen. nov. and the novel species name Metahyphopichia laotica gen. nov., sp. nov. are proposed for them. The type strain of the type species is 11-1006T(=CBS 13022T=CCY 092-001-001T=NCAIM Y.02126T) and was isolated in Luang Prabang (Laos). MycoBank registration numbers are MB 808253 (Metahyphopichia) and MB 808254 (Metahyphopichia laotica).

The exposure to contaminated water constitutes an important mechanism for the transmission of gastrointestinal pathogens. Diarrheagenic Escherichia coli strains cause enteric infections in humans and include six different categories according to virulence factors. This paper aims at detecting the presence of diarrheagenic E. coli strains in bathing waters of seven beaches of Lajeado Reservoir, in the Tocantins River in Brazil, and to test the resistance to antimicrobial drugs to correlate with possible contamination of the water with human feces. Total coliform and E. coli counts were done by the ColilertTM chromogenic substrate technique. Biochemical identification was accomplished by API20E and detection of virulence factors by PCR, employing specific primers for Shiga, LT, and ST and intimin genes. The susceptibility to 16 antibiotics was tested by disk-diffusion technique. Among one hundred and forty-nine strains of E. coli, two strains of EPEC and two of ETEC were detected in waters of beaches situated in urban areas, close to sewage discharge. These strains presented resistance to three to six antibiotics. Human origin is suggested based on the multiresistant profile of these strains.

Two novel yeast species were isolated from nectar of flower bracts of Heliconia psittacorum (Heliconiaceae) collected in a Cerrado ecosystem in the state of Tocantins, northern Brazil. Wickerhamiella pagnoccae sp. nov., which is closely related to Candida jalapaonensis, is heterothallic and produces one spheroid ascospore per ascus. Candida tocantinsensis sp. nov. belongs to the Metschnikowiaceae clade and its nearest relative is Candida ubatubensis, but the sequence identity (%) in the D1/D2 domains of the rRNA gene is low. The type strain of W. pagnoccae is UFMG-F18C1T ( = CBS 12178T = NRRL Y-48735T) and the type strain of C. tocantinsensis is UFMG-F16D1T ( = CBS 12177T = NRRL Y-48734T).

Our investigation of integrated biological control (IBC) started with an assay testing activity of the predacious yeast Saccharomycopsis crataegensis UFMG-DC19.2 against Penicillium digitatum LCP 4354, a very aggressive fungus that causes postharvest decay in oranges. Under unfavourable environmental conditions, the yeast showed a high potential for control (39.9% disease severity reduction) of this fungus. This result was decisive for the next step, in which S. crataegensis was tested in association with sodium bicarbonate salt, a generally regarded as safe (GRAS) substance. The yeast was able to survive at different concentrations of the salt (1%, 2% and 5%), and continued to grow for a week at the wound site, remaining viable at high population for 14 days on the fruit surface. The yeast alone reduced the severity of decay by 41.7% and sodium bicarbonate alone reduced severity of decay by 19.8%, whereas the application of both led to a delay in the development of symptoms from 2 to 10 days. Ingredients of the formulations were not aggressive to fruits since no lesions were produced in control experiments.

Thirty-eight specimens of free-rangingPodocnemis expansa(Amazon turtle) and 22 ofP. unifilis(Tracajá) were screened for yeast isolation from surface (plastron, skin, and nails), eye, and mouth cavity. A hundred and eighteen yeast isolates belonging to 39 species were obtained.Debaryomyces hansenii,Candida galli,C. sake, andRhodotorula mucilaginosawere the most frequent species isolated from these chelonians. Species diversity measured by Shannon's index was shown to be low and a degree of dominance could be detected as species known as potential pathogens were commonly isolated. The effective number of species in plastron ofP. expansawas higher than in mouth samples, but not inP. unifilisprobably due to dietary factors.P. expansaanimals were captured on the beaches, and the superficial yeast populations may include terrestrial species.P. unifilisanimals were captured in the water and the yeasts from superficial sites may represent species from river water.