Impact of Soluble and Exchangeable Concentrations of Elements in Surface Sediments from Recreational Areas on Culturable Bacterial Behaviors

Abstract

Contamination of major and trace elements in sediments is a global concern due to their potential risks to organisms. Bacteria also play vital roles in ecosystem processes and human health. However, the environmental adaptation of bacterial species due to human activities remains unclear. Therefore, in this study, surface sediments were collected from 12 recreational areas in Istanbul, Türkiye. Major and trace elements were determined in soluble and exchangeable fractions of sediments using inductively coupled plasma–optical emission spectrometry (ICP-OES). In addition, viability and primary biochemical and oxidative markers (protein, antioxidant, and lipid peroxidase) of gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa were assessed with exposure to soluble and exchangeable fractions of sediments from 1 to 42 h. The results showed that Na, Mg, K, Ca, P, Fe, Cu, Mn, Zn, and Al were present at average concentrations of 1254.1 ± 574.5, 234857.0 ± 126335.7, 109960.3 ± 73248.6, 201343.0 ± 84426.4, 124.0 ± 77.1, 129.5 ± 82.4, 36.0 ± 22.8, 25.2 ± 32.8, 26.3 ± 16.4, and 186.5 ± 76.7 mg/kg, respectively. The bacterial responses to the soluble and exchangeable fractions of sediments showed that approximately 27% of Staphylococcus aureus exhibited inhibition at short exposures; the inhibition levels were 14% to 34% for Pseudomonas aeruginosa. However, the inhibition decreased and no specific viability changes were observed at longer exposures compared to controls. The viability of bacteria is explained by the protein, antioxidant and lipid peroxidation with moderate and strong correlations. The bacterial responses were evaluated using elemental concentrations, and adaptation was explained by the correlation results.

Keywords:

• Beach sediment
• inductively coupled plasma–optical emission spectrometry (ICP-OES)
• metabolic activity
• metal analysis
• pathogens

Acknowledgments

This study was presented at the 12th Aegean Analytical Chemistry Days (AACD 2023).

Disclosure statement

The authors report there are no competing interests to declare.