Yeasts from tropical forests: Biodiversity, ecological interactions, and as sources of bioinnovation.

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. These unicellular fungi contribute to the recycling of organic matter, may serve as a food source for other organisms, or have ecological interactions that benefit or harm plants, animals, and other fungi. In this review, we summarize the most important studies of yeast biodiversity carried out in these biomes, as well as new data, and discuss the ecology of yeast genera frequently isolated from tropical forests and the potential of these microorganisms as a source of bioinnovation. We show that tropical forest biomes represent a tremendous source of new yeast species. Although many studies, most using culture-dependent methods, have already been carried out in Central America, South America, and Asia, the tropical forest biomes of Africa and Australasia remain an underexplored source of novel yeasts. We hope that this review will encourage new researchers to study yeasts in unexplored tropical forest habitats.

Teunomyces gombertii f.a., sp. nov., Teunomyces landelliae f.a., sp. nov., Teunomyces ledahaglerae f.a., sp. nov. and Teunomyces paulamoraisiae f.a., sp. nov., four yeast species isolated from mushrooms and drosophilids in a Brazilian Amazonian rainforest biome.

Ten yeast isolates representing four candidate novel species of the genus Teunomyces were obtained from different species of mushrooms and drosophilids collected in an Amazonian Forest biome in Brazil. Sequence analyses of the ITS 5.8S region and the D1/D2 domains of the large subunit rRNA gene showed that four isolates were phylogenetically related to Teunomyces stri, two isolates related to Teunomyces atbi, two isolates related to Teunomyces aglyptinius, and another two isolates related to Teunomyces aglyptinius, Teunomyces barrocoloradensis, Teunomyces gatunensis and Teunomyces stri. The four novel species differ by 3 % or more of sequence divergence in D1/D2 domains from their closest relatives. These species were isolated from basidiocarps of the mushrooms Marasmiellus volvatus, Tricholomopsis aurea, Hydropus sp. and Favolus tenuiculus, or drosophilids feeding on these substrates. The names Teunomyces gombertii f.a., sp. nov. (holotype CBS 16168T; Mycobank MB849065), Teunomyces landelliae f.a., sp. nov. (holotype =CBS 16169T; Mycobank MB 849066), Teunomyces ledahaglerae f.a., sp. nov. (holotype CBS 16170T; Mycobank MB 849067) and Teunomyces paulamoraisiae f.a., sp. nov. (holotype CBS 16120T; Mycobank MB 849068) are proposed for these species.

Kurtzmaniella hittingeri f.a., sp. nov., isolated from rotting wood and fruits, and transfer of three Candida species to the genus Kurtzmaniella as new combinations.

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 13469T (=UFMG CM-Y272T). 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.

Biodiversity loss along a gradient of deforestation in Amazonian agricultural landscapes.

Assessing how much management of agricultural landscapes, in addition to protected areas, can offset biodiversity erosion in the tropics is a central issue for conservation that still requires cross-taxonomic and landscape-scale studies. We measured the effects of Amazonia deforestation and subsequent land-use intensification in 6 agricultural areas (landscape scale), where we sampled plants and 4 animal groups (birds, earthworms, fruit flies, and moths). We assessed land-use intensification with a synthetic index based on landscape metrics (total area and relative percentages of land uses, edge density, mean patch density and diversity, and fractal structures at 5 dates from 1990 to 2007). Species richness decreased consistently as agricultural intensification increased despite slight differences in the responses of sampled groups. Globally, in moderately deforested landscapes species richness was relatively stable, and there was a clear threshold in biodiversity loss midway along the intensification gradient, mainly linked to a drop in forest cover and quality. Our results suggest anthropogenic landscapes with high-quality forest covering >40 % of the surface area may prevent biodiversity loss in Amazonia.

Spider species richness and sampling effort at Cracraft´S Belém Area of Endemism

ABSTRACT A list of spider species is presented for the Belém Area of Endemism, the most threatened region in the Amazon Basin, comprising portions of eastern State of Pará and western State of Maranhão, Brazil. The data are based both on records from the taxonomic and biodiversity survey literature and on scientific collection databases. A total of 319 identified species were recorded, with 318 occurring in Pará and only 22 in Maranhão. About 80% of species are recorded at the vicinities of the city of Belém, indicating that sampling effort have been strongly biased. To identify potentially high-diversity areas, discounting the effect of variations in sampling effort, the residues of a linear regression between the number of records and number of species mapped in each 0.25°grid cells were analyzed. One grid, representing the Alto Turiaçu Indigenous land, had the highest deviation from the expected from the linear regression, indicating high expected species richness. Several other grid cells showed intermediate values of the regression residuals, indicating species richness moderately above to the expected from the model.

Spider species richness and sampling effort at Cracraft´S Belém Area of Endemism.

A list of spider species is presented for the Belém Area of Endemism, the most threatened region in the Amazon Basin, comprising portions of eastern State of Pará and western State of Maranhão, Brazil. The data are based both on records from the taxonomic and biodiversity survey literature and on scientific collection databases. A total of 319 identified species were recorded, with 318 occurring in Pará and only 22 in Maranhão. About 80% of species are recorded at the vicinities of the city of Belém, indicating that sampling effort have been strongly biased. To identify potentially high-diversity areas, discounting the effect of variations in sampling effort, the residues of a linear regression between the number of records and number of species mapped in each 0.25°grid cells were analyzed. One grid, representing the Alto Turiaçu Indigenous land, had the highest deviation from the expected from the linear regression, indicating high expected species richness. Several other grid cells showed intermediate values of the regression residuals, indicating species richness moderately above to the expected from the model.

A new Amazonian species from the Drosophila annulimana species group (Diptera, Drosophilidae) / Uma nova espécie amazônica pertencente ao grupo de espécies Drosophila annulimana (Diptera, Drosophilidae)

Drosophila caxiuana sp. nov., Drosophila subgenus, is described and illustrated. This new species was collected in the Amazonian Biome (Caquajó river, Portel, Pará, Brazil) and is an atypical species to the group due the unusual morphology of the male terminalia.

Drosophila caxiuana sp. nov., subgênero Drosophila, é descrita e ilustrada. Essa nova espécie foi coletada no Bioma Amazônico (Rio Caquajó, Portel, Pará, Brasil) e é uma espécie atípica deste grupo devido à morfologia incomum da terminália masculina.

The cost-effectiveness of biodiversity surveys in tropical forests.

The identification of high-performance indicator taxa that combine practical feasibility and ecological value requires an understanding of the costs and benefits of surveying different taxa. We present a generic and novel framework for identifying such taxa, and illustrate our approach using a large-scale assessment of 14 different higher taxa across three forest types in the Brazilian Amazon, estimating both the standardized survey cost and the ecological and biodiversity indicator value for each taxon. Survey costs varied by three orders of magnitude, and dung beetles and birds were identified as especially suitable for evaluating and monitoring the ecological consequences of habitat change in our study region. However, an exclusive focus on such taxa occurs at the expense of understanding patterns of diversity in other groups. To improve the cost-effectiveness of biodiversity research we encourage a combination of clearer research goals and the use of an objective evidence-based approach to selecting study taxa.

Sexual dimorphism of body size and sternopleural bristle number: a comparison of geographic populations of an invasive cosmopolitan drosophilid.

Zaprionus indianus is a cosmopolitan drosophilid, of Afrotropical origin, which has recently colonized South America. The sexual dimorphism (SD) of body size is low, males being almost as big as females. We investigated 10 natural populations, 5 from America and 5 from Africa, using the isofemale line technique. Three traits were measured on each fly: wing and thorax length and sternopleural bristle number. Two indices of SD were compared, and found to be highly correlated (r > 0.99). For the sake of simplicity, only the female/male (F/M) ratio was further considered. A significant genetic variability of SD was found in all cases, although with a low heritability (intra-class correlation of 0.13), about half the value found for the traits themselves. For size SD, we did not find any variation among continents or any latitudinal trend, and average values were 1.02 for wing length and 1.01 for thorax length. Bristle number SD was much greater (1.07). Among mass laboratory strains, SD was genetically much more variable than in recently collected populations, a likely consequence of laboratory drift. Altogether, SD, although genetically variable and prone to laboratory drift, is independent of size variations and presumably submitted to a stabilizing selection in nature.