We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Toxicity and disruption of quorum sensing in Aliivibrio fisheri by environmental chemicals: Impacts of selected contaminants and microplastics
Summary
Researchers examined the effects of copper, gadolinium, silver nanoparticles, and polyethylene microplastic beads on quorum sensing in the marine bacterium Aliivibrio fisheri, finding that both dissolved and particulate compounds can disrupt bioluminescence-based quorum signalling.
The purpose of this study was to examine the effects of dissolved and particulate compounds on quorum sensing in the marine luminescent bacterium Aliivibrio fisheri. Bacteria were exposed to increasing concentrations of CuSO4 (Cu2+), gadolinium chloride (Gd3+), 20-nm silver nanoparticles (nanoAg) and 1-3 μm microplastic polyethylene beads for 250 min. During this period, luminescence measurements were taken at 5-min intervals. Toxicity was first examined by measuring luminescence output at 5-min and 30-min incubation time. Based on the effective concentration that decreases luminescence by 20% (EC20), the compounds were toxic at the following concentrations in decreasing toxicity: Cu2+ (3.2 mg/L) < nanoAg (3.4 mg/L, reported) < Gd3+ (34 mg/L) < microplastics (2.6 g/L). The data revealed that luminescence changed non-linearly over time. In control bacteria, luminescence changed at eight specific major frequencies between 0.04 and 0.27 cycle/min after Fourier transformation of time-dependent luminescence data. The addition of dissolved Cu2+ and Gd3+ eliminated the amplitude changes at these frequencies in a concentration-dependent manner, indicating loss of quorum sensing between bacteria at concentrations below EC20. In the presence of nanoAg and microplastic beads, the decreases in amplitudes were modest but compressed the luminescence profiles, with shorter frequencies appearing at concentrations well below EC20. Thus, loss of communication between bacteria occurs at non-toxic concentrations. In addition, with exposure to a mixture of the above compounds at concentrations that do not produce effects for Gd3+, nanoAg and microplastics, Cu2+ toxicity was significantly enhanced, suggesting synergy. This study revealed for the first time that small microplastic particles and nanoparticles can disrupt quorum sensing in marine bacteria.
Sign in to start a discussion.
More Papers Like This
Quorum Sensing Regulates Bacterial Processes That Play a Major Role in Marine Biogeochemical Cycles
This review synthesizes knowledge of quorum sensing in marine bacteria, examining how cell-to-cell chemical communication coordinates bacterial behaviors including biofilm formation, bioluminescence, and organic matter cycling that drive marine biogeochemical processes. The authors identify quorum sensing disruption as an understudied consequence of chemical pollution, with potential to alter nutrient cycling in ocean ecosystems.
Heterogenous bioluminescence patterns, cell viability, and biofilm formation of Photobacterium leiognathi strains exposed to ground microplastics
Researchers found heterogeneous bioluminescence patterns, altered cell viability, and modified biofilm formation in luminescent bacteria exposed to microplastics, suggesting microplastics disrupt bacterial physiological signaling. The bioluminescence changes were polymer-type dependent, with some plastics causing inhibition and others stimulation.
Quorum sensing bacteria in microplastics epiphytic biofilms and their biological characteristics which potentially impact marine ecosystem
Researchers collected microplastics from the ocean and characterised the quorum-sensing bacteria living in their biofilms — microbes that communicate chemically to coordinate group behaviours like biofilm formation and antibiotic production. Eight different quorum-sensing bacterial strains were isolated from polypropylene and PVC microplastics, and their signalling molecules (AHLs) were profiled. The findings show that microplastics act as rafts dispersing complex microbial communities, including potentially harmful antibiotic-producing and biofilm-forming bacteria, across the global ocean.
Microplastics do not affect standard ecotoxicological endpoints in marine unicellular organisms
Bacteria and marine diatoms were exposed to polyethylene microplastics of 1–500 μm at concentrations above environmental levels, finding no acute toxicity on bioluminescence inhibition or algal growth by standard ISO endpoints. The results suggest that standard ecotoxicological endpoints are insufficiently sensitive to detect microplastic effects on marine microbial primary producers and decomposers.
High-throughput screening of combined toxicity of nanoplastics and coexisting pollutants using luminescent bacterium
Researchers developed a high-throughput screening method using luminescent bacteria to rapidly assess the combined toxicity of nanoplastics with heavy metals and antibiotics. They found that most metal-nanoplastic combinations produced antagonistic effects, while some antibiotic combinations showed additive or synergistic toxicity depending on nanoplastic surface properties. The study provides an efficient new tool for evaluating the complex mixture toxicity of nanoplastics with co-occurring pollutants in water.