Resumo em Inglês:

Abstract Plasmodium falciparum is known to cause severe malaria, current treatment consists in artemisinin-based combination therapy, but resistance can lead to treatment failure. Knowledge concerning P. falciparum essential proteins can be used for searching new antimalarials, among these a potential candidate is shikimate dehydrogenase (SDH), an enzyme part of the shikimate pathway which is responsible for producing endogenous aromatic amino acids. SDH from P. falciparum (PfSDH) is unexplored by the scientific community, therefore, this study aims to establish the first protocol for active PfSDH expression. Putative PfSDH nucleotide sequence was used to construct an optimized expression vector pET28a+PfSDH inserted in E. coli BL21(DE3). As a result, optimal expression conditions were acquired by varying IPTG and temperature through time. Western Blot analysis was applied to verify appropriate PfSDH expression, solubilization and purification started with lysis followed by two-steps IMAC purification. Enzyme activity was measured spectrophotometrically by NADPH oxidation, optimal PfSDH expression occur at 0.1 mM IPTG for 48 hours growing at 37 °C and shaking at 200 rpm, recombinant PfSDH obtained after purification was soluble, pure and its physiological catalysis was confirmed. Thus, this study describes the first protocol for heterologous expression of PfSDH in soluble and active form.

Resumo em Inglês:

Abstract Hypostomus soniae is a small sized armored catfish endemic to the Tapajos River basin and ranked as one of the most exploited ornamental fish in the Santarem export marketplace. This study aims to evaluate distributional patterns of Hypostomus soniae and contribute to the species conservation in the face of development of the ornamental fish trade in the Amazon region. We compiled data associated with geographic coordinates in public repositories, supplemented with original field records. We compared our data to published records in the literature and museum collections to check for accuracy. To investigate the fishery and commercialization of H. soniae, we conducted interviews with ornamental fish stakeholders from the local trade. We also made direct observations in the fishing sites and export facilities in Santarem. A cluster analysis of the geolocation data was carried out to explore the spatial distribution patterns. The volume of captures and exportation of H. soniae decreased during the period 2020-2023. The occurrence of H. soniae was associated with annual rainfall ranging from 2,000 mm to 2,500 mm and concentrated in two municipalities of the State of Mato Grosso and two of the Para State. The species distribution area has been threatened, unfortunately, by fishermen who do not respect the laws that support artisanal fishing in the Amazon.

Resumo em Inglês:

Abstract The family Hymenochaetaceae includes a diversity of 893 species described around the world. Its representatives are known by their usually rusty colored basidiomes with a poroid hymenial surface, hydnoid or smooth, woody consistency, and wide morphological variation regarding the arrangement on the substrate. They behave as saprophytic, parasitic, ectomycorrhizal and play a fundamental role in the decomposition of wood in forest ecosystems. In the Brazilian Amazonia region, approximately 40 species of Hymenochaetaceae are currently recorded. The main goal of this study was to increase the knowledge on Hymenochaetaceae from the Brazilian Amazonia. Collections were carried out between October 2021 and April 2022 in the state of Pará, municipalities of Tomé-Açu and Bujaru, to expanding the knowledge of this fungal family to the Brazilian Amazonia. A total of 15 specimens were identified, distributed in seven genera and 12 species. Four species are new records for the state of Pará (Fomitiporia apiahyna, Phellinus neocallimorphus, Phellinus sancti-georgii, and Sclerotus extensus) and two of them are new records for the Brazilian Amazonia (P. neocallimorphus and P. sancti-georgii). Our findings contribute to taxonomic knowledge of this family in the Brazilian Amazonia and reduce the information gaps about the diversity of species.