Phenanthrene bioaccumulation in the nematode Caenorhabditis elegans

Area of Science:

• Environmental toxicology
• Ecotoxicology
• Nematode biology

Background:

• The role of food in xenobiotic bioaccumulation and toxicity is complex and species-specific.
• Small invertebrates, such as nematodes, are often overlooked in bioaccumulation studies.
• Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants.

Purpose of the Study:

• To investigate the bioaccumulation of phenanthrene in the nematode Caenorhabditis elegans.
• To determine the relative contribution of dissolved phenanthrene versus dietary sources to bioaccumulation.
• To assess the impact of bacterial food presence on phenanthrene toxicokinetics.

Main Methods:

• Exposure of Caenorhabditis elegans to phenanthrene.
• Measurement of phenanthrene bioaccumulation and elimination in the presence and absence of bacterial food.
• Analysis of toxicokinetic parameters.

Main Results:

• Phenanthrene elimination in nematodes was biphasic, indicating a slow-exchanging pool or biotransformation.
• Dissolved phenanthrene was the dominant source of bioaccumulation, contributing significantly even with food present.
• Dietary sources accounted for only approximately 9% of the bioaccumulated phenanthrene.
• Toxicokinetic parameters differed between fed and unfed nematodes, potentially due to lipid reserve depletion.

Conclusions:

• Food availability has a limited impact on the primary source of phenanthrene bioaccumulation in C. elegans.
• Dissolved xenobiotics are a major contributor to bioaccumulation in nematodes, regardless of food presence.
• Nematodes' physiological state, such as lipid reserves, can influence toxicokinetic parameters.