Bioassessment of bioremediation products in aquatic systems using cytotoxic and in vitro immune function assays

Estuarine sediments and overlying water were collected from Back Bay Mississippi and placed in five 7.5 x 61 cm. glass-column mesocosms with a peristaltic recirculating system. Four columns received a sample of artificially weathered Louisiana Crude Oil spiked with either N + P, a PAH-metabolizing bacterial consortium collected in situ, or both. A fifth column excluded oil, bacteria, and nutrients. Aliphatic and aromatic fractions were extracted from each system and diluted in iso-octane. Poecoliopsis Hepatoma Cells (PLHC-1) and Rat Hepatoma Cells (H4IIE) were treated with 1/100--1/800 dilutions of each extract and protein synthesis, RNA synthesis, DNA synthesis, Cytochrome P4501A induction, and viability were determined. ∝-CD3 and ∝-IgM-stimulated proliferation of mouse lymphocytes, PWM-stimulated proliferation and PMA-stimulated oxidative burst activity of catfish lymphocytes and phagocytes, respective, were also determined. All extracts were overtly toxic to cell cultures compared to controls at a 1/100 dilution but only aliphatic fractions affected viability at higher dilutions. Aromatic fractions increased protein and RNA synthesis as well as induced P4501A at 1/400 and 1/800 dilutions. Fertilization with P + N increased toxic responses. Lymphocyte proliferation and fish phagocyte responses were more sensitive to aliphatic extracts. This approach may be useful for investigating the toxicity and biological impact of effluents