| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1143-1 | ||||
Resumo:The Brazilian Pantanal is characterized by flood and dry seasons and its diverse flora, which can survive the stress caused by both periods. Among the plant species, Vochysia divergens Pohl (“Cambará”) stands out due to its medicinal properties . The Brazilian Cerrado is a neighboring biome of the Pantanal, and is also highly diverse in flora. Among the plant species from Cerrado, the medicinal plant Stryphnodendron adstringens (Mart.) Coville (“Barbatimão”) stands out due to its antimicrobial properties. In the last years, the research group of the laboratory of Bioprospecção e Genética Molecular de Microrganismos (BioGeMM) from the Universidade Federal do Paraná (UFPR) has carried out several bioprospecting studies of endophytic actinobacteria isolated from medicinal plants located ,in these biomes, finding compounds with antimicrobial activities against clinical pathogens, phytopathogens and tumor cells. The potential for biologically secondary metabolites from endophytic actinobacteria is considered to be as great as the potential achieved from actinobacteria from any other ecosystem. There is increasing evidence for the existence of new species of endophytic actinobacteria in various medicinal plant tissues, and some even possess the ability to produce bioactive compounds with novel chemical structures not yet described in the literature. In this context, this work aims to isolate endophytic actinobacteria from the medicinal plants V. divergens and S. adstringens, belonging to the Pantanal and Cerrado biomes, respectively, and, furthermore, to identify the isolates at genus or species level by morphological and phylogenetic analyses, in order to provide important new information to expand the knowledge about endophytic actinobacteria, and explore their biotechnological potential. Leaves were collected by random selection from 24 specimens of V. divergens and S. adstringens during the dry season (September/2022) in the region near the Pantanal Research Base of the Universidade Federal do Mato Grosso do Sul (UFMS), in the Nhecolândia region (Corumbá, MS) along the MS-184 road in Pantanal, and Taunay region (Aquidauana, MS) along the BR-262 highway, characterized by the Cerrado biome. To eliminate all epiphytic microorganisms, petioles and leaves were superficially disinfected and then fragmented into 1cm2 pieces. The fragments were then deposited on Petri plates with SCA (starch-casein-agar) culture medium, supplemented with nalidixic acid (50 μg/mL) and cycloheximide (50 μg/mL). Plates were incubated at 28°C for 30 days and purified colonies were subsequently evaluated by Gram staining. DNA extraction, PCR and partial 16S rDNA sequencing were performed to identify the isolates at the genus or species level. 247 endophytic bacteria were isolated, 187 and 60 isolates from V. divergens and S. adstringens, respectively. From these, 195 Gram-positive isolates were selected, 149 and 46 from V. divergens and S. adstringens, respectively. So far, the DNA sequencing and phylogenetic analyses enabled the identification of eight actinobacteria strains from V. divergens plant tissues, five belonging to the Curtobacterium genus and 3 to the Kocuria genus. Overall, these results so far highlight V. divergens and S. adstringens as promising sources of endophytic actinobacteria, which can be further explored through in vitro approaches for the production of new biocompounds. Palavras-chave: Biodiversity, Stryphnodendron adstringens, Vochysia divergens Agência de fomento:CAPES, CNPQ | |||||