Sheyla Regina Marques Couceiro's research while affiliated with Universidade Federal do Oeste do Pará and other places

Strains of gasteroid fungi are capable of oxidizing phenolic components and producing enzymes of great commercial value. However, the difficulty in producing biomass and, consequently, the low levels of expression of enzymes produced by these fungi hinder the advancement of biotechnological studies. A possible alternative may be supplementing the culture medium with lignocellulosic substrates, as observed in the cultivation of edible mushrooms, for example. Thus, the objective of this study was to analyze the effect of supplementing a potato-based culture medium with different concentrations of wheat and rice bran on mycelial development and the production of phenoloxidase enzymes of Amazonian strains of Cyathus and Geastrum. The basidiomas were collected in the Amazon of Pará, and the strains were obtained from mycelial isolation on Potato Dextrose Agar (PDA) medium. The strains were inoculated in semi-solid and liquid potato-based medium containing 10% and 20% rice bran and 10% and 20% wheat bran. For a period of 20 days, mycelial growth was observed in solid form, and for 40 days, the development of the strains in liquid medium was monitored, all incubated at 25°C in the dark. Growth and production of fresh and dry biomass were measured, as well as the production of phenoloxidase, arising from growth in liquid medium. Supplementation using 10% wheat bran was the most promising for the radial growth of four of the six species tested (C. limbatus, G. hirsutum, G. echinulatum, and G. schweinitzii), in addition to being the best treatment for the production of biomass and phenoloxidase enzymes for all species. Considering that wheat bran is easily accessible, this study stimulates basic science, especially in the Amazon, where Funga is still underestimated in terms of diversity and biotechnological potential.

Amazonian strains of Cyathus spp. and Geastrum spp. were studied for the ability to discolor the trypan blue azo dye and reduce its toxicity. Discoloration of trypan blue dye (0.05%) was evaluated in solid and aqueous medium over different periods. The reduction of dye toxicity after treatment was assessed by seed germination and the development of lettuce seedlings (Lactuca sativa L.) and toxicity test in Artemia salina (L.) larvae. All evaluated strains showed the potential to reduce the color intensity of trypan blue dye. Cyathus strains reached 96% discoloration, and C. albinus and C. limbatus also reduced dye toxicity. Geastrum strains showed a high efficiency degree in color reduction, reaching 98% discoloration, however, the by-products generated during the process presented toxicity and require further investigation. For the first time, Amazonian strains of gasteroid fungi degrading trypan blue are reported, some even reducing its toxicity. Thus, making them promising sources of enzymes of interest to bioremediation scenarios involving synthetic dyes.

Sphaerobolus stellatus Tode is a fascinating gasteroid fungus that is distinguished from other fungi by the diminutive morphology of the starry basidiome when mature and its peculiar strategy of spore’s dispersion. This taxon ejects the gleba for a considerable distance as if it was cannon, and therefore is popularly known as artillery fungus. Although the species is cosmopolitan, records are seldom in regions such as South America, and many of them require greater attention due to the absence of important morphological characters. In Brazil, the South American country with most records, the distribution was restricted to a few sites, none of them in the Amazon. This study describes the occurrence of S. stellatus from the Amazon, contributing to the understanding of its geographical distribution and making the material available for future diversity studies.

We present an inventory of polypore fungi (Basidiomycota; Hymenochaetales and Polyporales) with the aim of knowing the diversity of an area of 8 km2 of Brazilian Amazon rainforest, in the surroundings of HPP Sílvio Braga, in the west of Pará, where 91 species were collected (545 specimens), with 16 of these new records for the state of Pará, and 1 for America. These numbers tend to increase, given the projected occurrence of 118 species for the area. 87 species were considered occasional or rare, with only four considered frequent and none abundant. The richness observed in the study area was similar to other conservation units in the Amazon, for example, Caxiuanã National Forest (74 species). This observation, added to the potential increase in the number of species, the number of species with low representativeness (relative frequency) and the number of new records for the state, demonstrate the need to expand studies on polypore fungi in the region to learn about their biodiversity and the need for conservation of that area.

Hymenochaetales and Polyporales are important macrofungi for the maintenance of tropical forests, since they act directly in the nutrient cycling of the wood decomposition. In the Amazon, the largest tropical forest in the world, knowledge about Agaricomycetes is still insipient, since many areas have not yet been inventoried and new records appear each new study. To increase ecological knowledge about the Hymenochaetales and Polyporales, in the Brazilian Amazon region, collections were conducted in western Pará, Brazil, relating these fungi to the substrate they colonize and to environmental variables. 91 species were identified, with greater macrofungi richness associated with the rainy season; these fungi showed preferences for dead woods, of small diameter (class 1 = 5,9 ˫ 39 cm) and, in stages of decomposition still rigid or intermediate. The abundance and richness of Hymenochaetales and Polyporales were influenced by air humidity and the assemblage composition was influenced by temperature, air humidity and rainfall. The results indicate a rich diversity for western Pará region, these species are associated with environmental conditions, and may be threatened by the increasing pressure of human activity in the Brazilian Amazon.