ABSTRACT As primary decomposers of organic matter, mucoralean fungi have an important ecological role in edaphic systems in the Atlantic Forest. However, there is a knowledge gap regarding how communities of Mucorales are structured in soils of Atlantic Forest areas, and whether these communities are influenced by edaphic attributes in this domain. Thus, the current study aimed to understand the influence of edaphic attributes linked to species richness, abundance and composition of Mucorales in dense ombrophilous forest, ‘tabuleiro’ forest, sandbank and mangrove ecosystems located in Pernambuco, Brazil. Altogether, twenty-three taxa, including seven new records, were reported from soil samples from the ecosystems. Species composition was similar among the ecosystems, except for mangrove, while species richness and diversity of Mucorales were highest in dense ombrophilous forest and ‘tabuleiro’. Together the soil variables were responsible for 35.5 % of the variation in species composition, with pH being responsible for 53.32 % and 47.24 % of the variation in richness and abundance of these communities, respectively. These data indicate that pH is the most important attribute in delimiting the structure of mucoralean communities in the study areas, with influence on the composition, richness, and abundance of these fungi.
ABSTRACT During a survey of Mucorales in soil from an upland forest area in Pernambuco, Brazil, two specimens were isolated and characterized based on their morphological, physiological, and molecular data (ITS and LSU rDNA). Phylogenetic analyses of the isolates revealed that the strains URM 8209 and URM 8210 are closely related to species of Absidia. URM 8209 forms conical, subglobose, and strawberry-shaped columellae and the sporangiospores are cylindrical and ellipsoid. URM 8210 produces hemispheric, subglobose, and strawberry-shaped columellae and the sporangiospores are globose, subglobose, ellipsoid, and short cylindrical. Based on evidence obtained through analysis of datasets (LSU and ITS rDNA regions), A. saloaensis sp. nov. (URM 8209) and A. multispora sp. nov. (URM 8210) are proposed here as novel species of Absidia. A table with morphological characteristics of Neotropical Absidia spp. is provided.
Stainless steel and nickel alloy have high corrosion resistance in high-temperature environments due to the high Cr content present in their chemical composition, being widely used in components of nuclear reactors, petrochemical industries, etc. Through proper processes and procedures, it becomes possible to join these alloys. However, this union can generate detrimental factors in its performance, among them, the residual stresses. In this work, the residual stresses generated by the autogenous GTAW process, due to different interpass temperatures on the weld bead geometry, were analyzed by the Hole-Drilling technique in dissimilar welding joints of stainless steel AISI 316L and Inconel 718 alloy. In addition, the Vickers microhardness measurements were carried out to evaluate the hardness profile in the cross section of the weld bead covering base metal (BM), heat affect zone (HAZ) and weld metal (WM). We found that in the interface region between BM and HAZ of each dissimilar joint metal, residual stresses increased above 300 MPa, while hardness increased above 160 HV.
Abstract Mucorales comprises fungi commonly isolated as saprobes from soil, dung, stored grains and plants. Although these fungi have been studied in several countries, there are relatively a few reports of them in semi-arid areas. Therefore, the aims of the present study were to assess and compare the Mucorales communities in dung from different species and breeds of herbivores in the semi-arid of Pernambuco, based on the frequency of occurrence and species richness of these fungi. Samples of dung collected in the cities of Arcoverde, Serra Talhada and Sertânia were incubated in moist chambers in triplicate. Altogether, 24 taxa of Mucorales distributed in the genera Absidia, Circinella, Cunninghamella, Lichtheimia, Mucor, Pilobolus, Rhizopus and Syncephalastrum were identified. The highest species richness was found in sheep excrement. Mucor circinelloides f. griseo-cyanus was the most common taxon, followed by M. ramosissimus. The similarity of the composition of Mucorales species was greatest between the excrements of Guzerá and Sindi breeds (bovine). All mucoralean species isolated are being cited for the first time from animal dung found in Caatinga and a new species of Mucor was recorded. An identification key for species of Mucorales from dung in the semi-arid region of Brazil is provided.
Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora.
Resumo Um levantamento atualizado das plantas com sementes e análises relevantes acerca desta biodiversidade são apresentados. Este trabalho se iniciou em 2010 com a publicação do Catálogo de Plantas e Fungos e, desde então vem sendo atualizado por mais de 430 especialistas trabalhando online. O Brasil abriga atualmente 32.086 espécies nativas de Angiospermas e 23 espécies nativas de Gimnospermas e estes novos dados mostram um aumento de 3% da riqueza em relação a 2010. A Amazônia é o Domínio Fitogeográfico com o maior número de espécies de Gimnospermas, enquanto que a Floresta Atlântica possui a maior riqueza de Angiospermas. Houve um crescimento considerável no número de espécies e nas taxas de endemismo para a maioria dos Domínios (Caatinga, Cerrado, Floresta Atlântica, Pampa e Pantanal), com exceção da Amazônia que apresentou uma diminuição de 2,5% de endemicidade. Entretanto, a maior parte das plantas com sementes que ocorrem no Brasil (57,4%) é endêmica deste território. A proporção de formas de vida varia de acordo com os diferentes Domínios: árvores são mais expressivas na Amazônia e Floresta Atlântica do que nos outros biomas, ervas são dominantes no Pampa e as lianas apresentam riqueza expressiva na Amazônia, Floresta Atlântica e Pantanal. Este trabalho não só quantifica a biodiversidade brasileira, mas também indica as lacunas de conhecimento e o desafio a ser enfrentado para a conservação desta flora.