| Congresso Brasileiro de Microbiologia 2023 | Resumo: 812-1 | ||||
Resumo:Cyanobacteria are prokaryotic organisms with morphological diversity, including cylindrical, oval, and filamentous cellular forms. They have great adaptive capacity and are found in diverse environments. Filamentous cyanobacteria have associated microorganisms due to the structuring of microenvironments formed by the filaments and mucilage. These interactions can promote positive or negative symbiotic relationships. The filamentous cyanobacterium Capilliphycus salinus ALCB114379 is a marine, halophilic organism that belongs to the Oscillatoriales order. It was recently described as a new genus, Capilliphycus. The aim of this study was to identify and evaluate the symbiotic relationships of the microorganisms associated with the cyanobacterium Capilliphycus salinus ALCB114379. The morphological and taxonomic analysis of the cyanobacterium was performed using optical microscopy, while the identification of exopolysaccharides on its filaments was performed using scanning electron microscopy. After sequencing the genome of Capilliphycus salinus ALCB114379 using PacBio HiFi, a classification analysis of the reads using the Kaiju tool indicated a gene predominance derived from Proteobacteria, corresponding to 69% of the sequences, while only 25% were classified as cyanobacteria. Five distinct Proteobacteria genomes were assembled using the Flye tool. To determine the taxonomic classification of each genome, the GTDB and Type (Strain) Genome Server tools were used. The quality and completeness of these assemblies were evaluated using the Quast, CheckM, and BUSCO tools. For each genome, potential functional genes were identified using Prokka and subsequently categorized into biological subsystems using BastKOALA. After this step, the gene annotations were analyzed in two distinct sets using the OrthoVenn2 tool: the singletons, which correspond to genes found in only one of the identified lineages, and the clusters of genes shared by two or more lineages. The analysis identified shared genes among the proteobacteria associated with cyanobacteria, specifically related to the nitrogen cycle, particularly in the anaerobic respiration stage. The gene cluster for the nitrogenase enzyme was found in the cyanobacterium C. salinus ALCB114379, even though it is not a heterocystous cyanobacterium. This suggests the presence of anoxic or hypoxic microenvironments facilitated by the host, enabling this symbiotic relationship. Palavras-chave: Cyanosphere, Functional Annotation, Microenvironments, Microscopy, Symbiotic Relationships Agência de fomento:CAPES | |||||