Growing concern over environmental contamination has stimulated rigorous efforts to establish reliable biological monitoring assays. Methodology was developed for measuring photoinduced short- and long-term @entity137 of an important group of contaminants, @entity2555 ( @entity2556 ), using the luminescent bacterium @entity7866 . The @entity137 of most @entity2556 can be greatly enhanced on exposure of a living organism and/or the chemicals to ultraviolet (UV) radiation. There are two major mechanisms involved in photoinduced @entity137 of @entity2556 : photosensitization and photomodification. In the former, production of singlet @entity26 leads to cellular damage. In the latter, photooxidation of @entity2556 results in new compounds (usually oxygenated @entity2556 ) that are often more toxic than their parent @entity2556 . Microbial @entity137 assays were developed to measure short- and long-term photoinduced @entity137 of @entity2556 . The bioassays were based on inhibition of luminescence and growth of @entity7866 . The short-term assay should detect @entity137 of chemicals that are taken up rapidly and/or whose photosensitization activity is immediate. The long-term assay should identify chemicals where the rate of assimilation is slow and/or time is required for photoinduced effects to be realized. The assays were tested with 12 different @entity2556 . The short-term assay did not reveal photoinduced @entity137 for any of the test chemicals. However, photoinduced @entity137 was apparent in the long-term assay, indicating that short-term assays may be opaque to this key mechanism of @entity2556 @entity137 .

Measurement of short- and long-term XXXX of @entity2555 using luminescent bacteria.

@entity137 :: ('MESH:D064420', 'Disease') :: ['toxicity'] @entity7866 :: ('668', 'Species') :: ['Vibrio fischeri', 'V. fischeri'] @entity2555 :: ('MESH:D011084', 'Chemical') :: ['polycyclic aromatic hydrocarbons'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity2556 :: ('CHEBI:33848', 'Chemical') :: ['PAHs', 'PAH']
@entity137 :: (MESH:D064420,Disease) :: ['toxicity']
