Bioluminescent Vibrio fischeri Assays in the Assessment of Seasonal and Spatial Patterns in Toxicity of Contaminated River Sediments

Abstract

Several bacteria-based assays, notably Vibrio fischeri luminescence assays, are often used as environmental monitoring tool for toxicity in sediments that may serve as both sinks and secondary source of contamination in aquatic ecosystems. In this study, we used 30-s kinetic bioassays based on V. fischeri to evaluate the toxicity associated to sediments from five localities with different contamination inputs (Morava River and its tributary Drevnice River in the south-eastern part of the Czech Republic). Toxicity assessed as half maximal inhibitory concentration (IC50) over the course of a year-long sampling was compared in bottom sediments and freshly trapped particulate material. Standard approach based on testing of aqueous elutriates was compared with toxicity of whole sediments (contact suspension toxicity). Bottom sediments showed lower toxicity compared to freshly trapped suspended materials in all cases. On the other hand, standardized elutriates induced generally weaker effects than suspended sediments likely due to losses during the extraction process. Toxicity generally increased during winter reaching maximum peaks in early spring months in all five sites. Total organic carbon (TOC) was found to be highly correlated with toxic effects. Toxicity from sites with direct industrial and agricultural water inputs also correlated with concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). Single time point sampling followed by the extraction and testing of elutriates, do not truly reflect the spatial and temporal variability in natural sediments and may lead to underestimation of ecotoxic risks.

Interaction Analysis of Commercial Graphene Oxide Nanoparticles with Unicellular Systems and Biomolecules

“…The 96-well plate was incubated in a Thermomixer at 800 rpm and 15 • C, and V. fischeri luminescence was measured for 30 min using a microplate reader (Synergy-HT, BioTek). The luminescence inhibition (using as reference the negative control condition) was calculated using the values obtained at 10 (M10) and 30 (M30) min using the following formula, adapted from Jarque et al (2016) [68], where CF is a correction factor (the Mt/peak ratio in negative controls) reflecting natural attenuation of bacterial luminescence after 30 min of incubation in non-exposed conditions:…”

Differential gene expression of Australian Cricotopus draysoni (Diptera: Chironomidae) populations reveals seasonal association in detoxification gene regulation

“…Firstly, we lacked actual water quality data for either site during the sampling period, which limits the strength of our inferences of the relationship between rainfall, pollution, and gene expression. Further, we lack data at both sites concerning sediment pollutant levels, and monitoring the episodic mobilization of sediment-bound pollutants requires near-continuous sampling to be informative 54 , 55 . Taking water and sediment samples at the same time as insects were sampled would have added strength to the interpretation of patterns in this study, but unfortunately outside the scope of this project.…”

Evaluating the Ecotoxicity of Different Pharmaceuticals Using Aliivibrio Fischeri Bioassays

“…Within the biological methods developed in the last decades, bacterial tests have become particularly well known for being simple, fast, and inexpensive, with good correlations with other toxicity tests responses, including with superior organisms. As a result, bacterial bioluminescence inhibition tests are usually the first choice for testing potential toxicity of PHACs from environmental samples [21,22]. Overall, PHACs could induce an acute and chronic toxic effect in aquatic species, bio accumulate in ecosystems and decrease their biodiversity [12,21].…”