Potential application of Pseudomonas stutzeri W228 for removal of copper and lead from marine environments

• Published in: PloS one 2020-10, Vol.15 (10), p.e0240486
• Main Authors: Coelho da Costa Waite, Carolina, Oliveira Andrade da Silva, Guilherme, Pires Bitencourt, José Augusto, Pereira Torres Chequer, Luciana, Pennafirme, Simone, de Azevedo Jurelevicius, Diogo, Seldin, Lucy, Araújo Carlos Crapez, Mirian
• Format: Article
• Language: English
• Subjects: Absorption; Bacteria; Bacterial Proteins - metabolism; Bacteriological Techniques; Bioassays; Biodegradation, Environmental; Biological assays; Biology and Life Sciences; Biomass; Bioremediation; Brazil; Chemical properties; Consortia; Copper; Copper (Metal); Copper - metabolism; Earth Sciences; Efflux; Energy demand; Environmental aspects; Enzymatic activity; Esterase; Esterases; Esterases - metabolism; Extracellular Polymeric Substance Matrix - metabolism; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Enzymologic; Geologic Sediments - microbiology; Heavy metals; Laboratories; Lead; Lead (Metal); Lead - metabolism; Life cycles; Marine environment; Marine sediments; Metal concentrations; Metals; Methods; Microorganisms; Oxidoreductases - metabolism; Physical Sciences; Physiological aspects; Pseudomonas; Pseudomonas stutzeri; Pseudomonas stutzeri - enzymology; Pseudomonas stutzeri - growth & development; Research and Analysis Methods; Sediments; Social Sciences; Software; Water Pollutants, Chemical - metabolism
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0240486

High concentrations of metals in the environment alter bacterial diversity, selecting resistant and tolerant species. The study evaluated the selection of a potential bacterial strain from Sepetiba Bay-Rio de Janeiro, Brazil marine sediments to remove Cu and Pb. The bacterial strain isolated from the sediments was used in three different bioassays: (1) Cu at concentrations of 0 (control), 6 and 50 μg.mL-1; (2) Pb at concentrations of 0 (control), 6 and 50 μg.mL-1; (3) Cu + Pb in concentrations of 3 μg.mL-1 Cu + 3 μg.mL-1 Pb (6 μg.mL-1) and 25 μg.mL-1 Cu + 25 μg.mL-1 Pb (50 μg.mL-1). The number of cells and the enzymatic activities of dehydrogenases and esterases were quantified. Results of taxonomic identification indicated the selection of the Pseudomonas stutzeri W228 strain, showing a greater degree of similarity (±73%) with the database used. There was no significant variation in the number of cells, 108 cells.mL-1, which represents a high biomass production in the presence of stressors. However, we observed a reduction in dehydrogenase activity at all tested concentrations of Cu, Pb and Cu + Pb. The activity of esterase increased, indicating a higher energy demand to complete the bacterial life cycle. The study showed significant results for the absorption of Pb by the extracellular polymeric substances (EPS) and the efflux of Cu. The capacity of Pb absorption by EPS can be considered a resistance mechanism, as well as the efflux of Cu, so that the available EPS sites could be occupied by the most toxic ions demonstrating that Pseudomonas stutzeri is resistant to Pb and Cu.