| Congresso Brasileiro de Microbiologia 2023 | Resumo: 659-2 | ||||
Resumo:Since the first records of microbial diversity and ecology in studies performed with Amazonian Dark Earths (ADEs), ITS and 16S rRNA analysis have pointed out the presence of specific groups of bacteria, such as Archaea and Cyanobacteriota. However, these organisms remain underexplored, with only descriptions of their presence and absence over time. In recent years, there has been growing attention given to the phycosphere, described as the neighboring region surrounding plants, which act as a microenvironment sustaining complex microbial communities. Cyanobacteria are now receiving attention for their role in carbon and nitrogen fixation, as well as the production of specialized metabolites that might influence soil health and plant growth. Brazilian strains isolated from soil samples retrieved in the Hatahara archaeological site (Iranduba, Amazonas) offer a glimpse of the biotechnological and ecological potential related to the presence of cyanobacterial strains in ADEs. The genome of Amazonocrinis nigriterrae CENA67 presented several biosynthetic gene clusters (BGCs) of interest. For instance, genes related to mycosporine-like amino acids (MAAs), chloramphenicol drug resistance, geosmin production, and nitrogen fixation were all annotated with considerable sequence identity to reference strains (>75%). Other isolated strains, such as Nostoc sp. CENA68 and CENA70, and Dendronalium phyllosphericum CENA73, showed phylogenetic similarity to other cyanobacteria found in the Brazilian Rainforest. This might serve as evidence for the geological hypothesis of a connection between these two biomes. Phosphorus metabolism and shifts in land use are already aspects that correlate with cyanobacterial strains and their presence in the microbiota of the Amazon soils. The occurrence of cyanobacteria in ADEs studies is being reported more frequently, leading to the conclusion that isolating and assembling more genomes is a clear path that may provide further clues on cyanobacterial roles in the soil microbiota dynamics and unravel the potential of these microorganisms for agricultural and ecological research. Palavras-chave: Cyanobacteriota, Nitrogen, Phosphorus, Specialized metabolites, Terra Preta | |||||