https://repositorio.uema.br/jspui/handle/123456789/4607 Wed, 29 Jul 2026 06:50:42 GMT 2026-07-29T06:50:42Z http://repositorio.uema.br:80/jspui/retrieve/1f95e175-f66d-4e69-86cf-c57104bcee15/Bionorte.jpg https://repositorio.uema.br/jspui/handle/123456789/4607 https://repositorio.uema.br/jspui/handle/123456789/6329 Título: Atividade antibacteriana de Ageratum conyzoides L. sobre microrganismos patogênicos in vitro Abstact: The increasing problem of microbial resistance has intensified the search for new therapeutic alternatives from medicinal plants. Ageratum conyzoides L., popularly known as mentrasto, is highlighted for its bioactive compounds with recognized antimicrobial properties. This study evaluated the antibacterial potential of the essential oil, crude extract, and fractions of A. conyzoides L. against pathogenic microorganisms of public health importance, correlating chemical composition with biological activity. The essential oil was obtained by hydrodistillation, while the crude extract was prepared with solvents and fractionated, including the ethyl acetate fraction. Chemical characterization was performed using gas chromatography– mass spectrometry (GC-MS), which enabled the identification of major and minor compounds. Antimicrobial activity was assessed by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), using reference bacterial strains and comparing results with standard antibiotics. Cytotoxicity of the extracts and oil was also evaluated on RAW 264.7 murine macrophages through the MTT assay. The crude extract and especially the ethyl acetate fraction exhibited significant antibacterial effects, with MIC values consistent with relevant antimicrobial activity. GC-MS analysis revealed terpenes and flavonoids among the main metabolites, which likely contribute to the observed effects. The essential oil demonstrated a favorable safety profile, showing no significant cytotoxicity even at high concentrations (up to 1000 μg/mL). In conclusion, A. conyzoides L. represents a promising natural source of antimicrobial biomolecules with low cytotoxicity. The ethyl acetate fraction stood out as the most active, making it a strong candidate for further studies aiming at compound isolation and development of phytotherapeuti Thu, 28 Aug 2025 00:00:00 GMT https://repositorio.uema.br/jspui/handle/123456789/6329 2025-08-28T00:00:00Z https://repositorio.uema.br/jspui/handle/123456789/6233 Título: Aspectos tróficos, ecológicos e moleculares como ferramenta de monitoramento da biodiversidade em um Complexo Portuário na Costa Amazônica Brasileira Abstact: This study aims to estimate biological diversity through morphological and eDNA analyzes in the water and sediment of the São Marcos Estuarine Complex (SMEC), a region of great importance on the Amazon coast due to its ecological and socioeconomic significance. Samples were collected between 2018 and 2023 during the rainy and dry seasons. The results obtained using traditional methods (plankton nets, gillnets, dredges and other capture equipment, as well as taxonomic and morphological analysis) revealed a biological diversity distributed among the kingdoms Eubacteria, Chromista, Plantae, and Animalia, registering approximately 289 taxa. ß-diversity analysis indicated that species replacement accounted for about 90% of the total variation in community composition. Environmental conditions showed significant variations, with greater heterogeneity recorded during the dry season and in the years 2020 and 2023, marked by atypical events. Through eDNA samples, it was possible to recover sequences for the Archaea, Bacteria, and Eukaryota domains, recording 39 eukaryotic phyla. The 18S marker showed the highest yield and captured a wide diversity of microeukaryotes, while COI, although less specific, contributed to the detection of metazoans. Based on phytoplankton identification, four potentially harmful species were found. Furthermore, ecological indices indicate low diversity and moderate species richness. Using the Multimetric Trophic Index (TRIX), it was possible to observe a eutrophic environment, with compromised water quality due to the high nutrient load caused by the discharge of domestic and industrial effluents from human activities. Regarding in silico evaluation, primers related to the 18S gene were designed to maximize organism identification. The developed primers were effective in identifying phytoplankton at the species level. The results highlight the importance of assessing the environment in an integrated way, especially in a highly dynamic, diverse system subject to intense degradation. Mon, 22 Dec 2025 00:00:00 GMT https://repositorio.uema.br/jspui/handle/123456789/6233 2025-12-22T00:00:00Z https://repositorio.uema.br/jspui/handle/123456789/6223 Título: Aspectos biogeográficos e ecológicos de palmeiras de babaçu Abstact: The Cocais Forest, an emblematic vegetation formation in the Brazilian Mid-North, constitutes a unique ecological mosaic in which palm trees represent structural elements of the landscape, extending across several states and harbouring remarkable sociobiological diversity. Despite its ecological and cultural relevance, its spatial delimitation remains marked by conceptual and cartographic uncertainties, a biogeographical challenge, as it directly affects how the landscape is understood, planned and conserved. Among its most representative species are the palms of the Babassu Complex (Attalea spp.), recognised for their wide distribution and ecological dominance, as well as their social, economic and symbolic importance to the traditional communities that depend on them. However, both the babassu palm forests and the Cocais Forest itself are under increasing anthropogenic pressure due to land use conversion, habitat fragmentation and the effects of climate change. Thus, understanding these systems requires integrating spatial, ecological and social approaches capable of translating uncertainties into instruments applicable to conservation. In this context, this study sought to fill gaps in knowledge about the biogeographical uncertainties that permeate Cocais Forest and the Babassu Complex. Initially, a systematic review of existing spatial delimitations attributed to the Cocais Forest was carried out. Among the main results, seven sources were discovered that presented significant divergences in terms of their territorial extension and definition criteria. The delineation by Nascimento and Lima (2016) covered the largest area, and the overlap of the different maps allowed us to identify a zone of consensus, which was named the ‘core region,’ comprising 14 municipalities in the State of Maranhão. This cartographic synthesis resulted in a potential area of occurrence covering 392 municipalities distributed across five Brazilian states. Next, we employed Species Distribution Modelling (SDMs) for seven species of the Babassu Complex and for the group overall, using the Maximum Entropy (MaxEnt), Random Forest (RF), Boosted Regression Trees (BRT) and Generalised Linear Models (GLM) algorithms. Occurrence data from GBIF were combined with bioclimatic variables from CHELSA 2.1 under the current scenario (2011-2040) and future high emission scenarios (SSP3-7.0 and SSP5-8.5) for 2041–2070 and 2071–2100. The results indicated that RF and BRT generated more conservative projections, while MaxEnt and GLM presented broader distributions. Temperature seasonality was the main bioclimatic predictor. Attalea maripa, A. phalerata, and A. speciosa exhibited broader ranges of suitability, while A. funifera and A. vitrivir presented more restricted distributions. Future scenarios projected an increase in high suitability, particularly in the Amazon and Cerrado regions. Only A. funifera and A. vitrivir showed declines. By revealing how cartographic and predictive uncertainties limit territorial planning and ecosystem conservation, this study reinforces the importance of conservation biogeography as a strategic field for understanding and intervening in complex socio-ecological landscapes, especially in tropical regions subject to multiple environmental pressures. Fri, 12 Sep 2025 00:00:00 GMT https://repositorio.uema.br/jspui/handle/123456789/6223 2025-09-12T00:00:00Z https://repositorio.uema.br/jspui/handle/123456789/6175 Título: Relações entre a filogenética via DNA Barcode e traços funcionais de minhocas na Amazonia Oriental Abstact: Understanding the causes of variability in functional traits is an important question in earthworm ecology. While interspecific variation in anatomical dimensions for the same trait is well accepted, the role of environmental filters, soil degradation, and environmental stress in affecting the variability of functional traits is not well understood. In this study, we sought to determine the relative importance of environmental factors and earthworm species taxonomy on the variability in functional traits within species (intraspecific variability). We focused on eight functional traits including body mass, body length, body diameter, gizzard, gizzard thickness, septum thickness, typhlosole, and gut organic matter. We sampled earthworms of 11 different species in various regions of the eastern Amazon to determine the general responses of different species' characteristics when exposed to various ecosystem and soil conditions. Our results suggest that the functional traits of earthworms are influenced in different ways by environmental conditions. One set of traits, including body mass, body length, and body diameter, was more constant and independent of environmental variability, while another set, including gizzard diameter and length, gizzard muscle thickness, septum thickness, typhlosole, and intestinal organic matter, was more sensitive. The most affected by different environmental variables was septum thickness. We also examined which environmental factors are most important for trait variability. Our study highlights the importance of considering both environmental factors and taxonomic classification when studying the variability of functional traits within earthworm species. Overall, our results suggest that taxonomic classification alone is a good guide for estimating the major functional traits of earthworms in the Brazilian Amazon, but local conditions can their variability is which is essential for informing conservation efforts and maintaining ecosystem function. In the second chapter of this thesis, we focused on the utilization of the molecular tool known as DNA Barcodes, which enables the identification of species groups with unknown taxonomy. The utilization of DNA Barcodes produces UOTMs (Molecular Taxonomic Operational Units), which can serve as morphospecies to characterize the diversity and structure of communities, as well as to investigate the relationships between soil attributes and ecological processes. Thus, the objective of this study was to explore the potential of DNA Barcodes in assessing phylogenetic diversity. Specifically, we utilized the COI gene region to analyze new species of annelids and compare their identification with classical taxonomy. We extracted DNA from a total of 1,014 earthworm samples; however, only 56 samples were successfully sequenced. Despite encountering technical challenges during the sample amplification and sequencing process, our results revealed the formation of clusters among earthworm species and certain genus-level groups, which had already been identified through classical taxonomy and were further supported by phylogenetic analysis (e.g., Pontoscolex and Andiorhinus) due to their significant similarity to existing databases. In conclusion, the data presented in this chapter necessitate revisiting and repeating the amplification and sequencing procedures to ensure accuracy and reliability Mon, 30 Oct 2023 00:00:00 GMT https://repositorio.uema.br/jspui/handle/123456789/6175 2023-10-30T00:00:00Z