| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1266-1 | ||||
Resumo:Cigarette butts are emerging residue present on tourist beaches around the world, it is a residue commonly discarded by beach users, and it can be transported by the wind from continental areas to the sea; in some cases, they can be mixed in discharges from wastewater systems and/or urban drainage. Cigarette butts are highly persistent residues in ecosystems, due to their low degradability and long decomposition times. With the passage of time and the environmental conditions of humidity, temperature, organic matter, and granulometry of the sand, they can become niches for microbiological contamination, which can potentially affect human health and ecosystems. The objective of the study was to determine the potential of cigarette butts as microbiological niches present in tourist beaches; for which a pilot beach was taken, the Bocagrande beach located in Cartagena de Indias, Colombian Caribbean (75° 33' 42.0'' W 10° 28' 56.7'' N). Collection of the material consisted of composite samples of marine sand in seven collections from June to December 2022, including both dry and rainy seasons. Samples were composed of butts and fibers in the sandy substrates. The methodology used for bacterial identification included three stages, i. Isolation of the bacteria: for which broth and LB agar modified with seawater were used ii. Morphological and biochemical characterization of the isolated strains: through Gram staining, catalase, oxidase, and BBL Crystal tests; iii. For the phylogenetic analyses based on our 16S rRNA gene sequence for the genus Virgibacillus, we searched 16S rRNA records in the RefSeq database-NCBI. The sequences were aligned using the Mafft program (v7.487) before being used by IQtree (v1.6.12) to construct a maximum-likelihood tree, using the best substitution model (GTR+F+I+G4) and executing bootstrap with 1000 replicates to assess branch support. For the visualization of the tree, we utilized the web tool iTOL (v6). Molecular sequence analysis of the 16S rRNA gene indicated that the strains were phylogenetically related to Virgibacillus pantothenticus and Virgibacillus dokdonensis species. This is the first report of these strains on the beaches of Cartagena de Indias-Colombia. This genus of Gram-positive bacteria is rod-shaped, catalase positive, and under stressful environmental conditions, the bacterium can produce endospores. In conclusion, the cigarette butts from the sand of the Colombian Caribbean beaches; are a potential niche for the isolation of bacteria, which may be promising resources to assess environmental health in marine-coastal ecosystems. Palavras-chave: beach sand, cigarette butts, emerging pollutants, molecular diagnosis, bacteria | |||||