spiking pyrene onto algae

Charles Miller rellim at tulane.edu
Fri Dec 15 10:34:39 EST 2000


Try these references for a spiking protocol......


Ecotoxicol Environ Saf 1998 Sep;41(1):83-9
Role of algae in fate of carcinogenic polycyclic aromatic hydrocarbons in
the aquatic environment.
Kirso U, Irha N
Environmental Chemistry Group, Institute of Chemical Physics and Biophysics,
Tallinn, Akadeemia tee 23, EE0026, Estonia.
Polycyclic aromatic hydrocarbons (PAHs) represent an ecotoxicologically
relevant, combustion-related substance group. The bioconcentration and
transformation of a priority PAH, benzo[a]pyrene (BaP), by brown (Fucus
vesiculosus and Chorda filum), red (Furcellaria lumbricalis), green
(Enteromorpha intestinalis, and Cladophora glomerata), and chara (Chara
aspera) algae have been studied. A flux budget was made of the amounts of
BaP that are accumulated and metabolized by different algae during an
estimated time. The results indicated that of all the BaP consumed, 89-99%
was found in the biomass of Fucus, an insignificant part was in the
solution, and the remainder (up to 4%) was not recovered, i.e., was
considered to have been metabolized. For green and chara algae the
proportion of transformed PAHs was more essential, 42-49%. The
transformation of BaP in marine and freshwater algae is species specific and
depends on the presence and activity of enzymes localized in the plant
cells. The most important enzyme systems for detoxification of BaP are
o-diphenol oxidase, cytochrome P450, and peroxidase. The data obtained
indicate the important role of marine and freshwater algae in the fate of
carcinogenic PAHs in the environment. Copyright 1998 Academic Press.
PMID: 9756694, UI: 98434758

Chemosphere 1998 Jun;36(15):3181-97
The assimilation of contaminants from suspended sediment and algae by the
zebra mussel, Dreissena polymorpha.
Gossiaux DC, Landrum PF, Fisher SW
Great Lakes Environmental Research Laboratory, National Oceanic and
Atmospheric Administration, Ann Arbor, MI 48105, USA.
Since their invasion into the Great Lakes, zebra mussels, Dreissena
polymorpha, have increased the water clarity in Lake St. Clair and Lake Erie
due to their extensive particle filtration. Because these particles contain
sorbed contaminants, the potential for contaminant accumulation from both
suspended sediment and algae were examined. Sediment or algae were dosed
with selected radiolabeled polycyclic aromatic hydrocarbon congeners and/or
hexachlorobiphenyl (HCBP). Assimilation efficiencies were measured and
depended on food quality. Zebra mussels, 17 +/- 2 mm long, assimilated 58.3
+/- 13.5% of the pyrene and 44.7 +/- 5.8% of the benzo(a)pyrene (BaP) from
sediment particles with a particle clearance rate of 493-897 ml/g tissue/h.
However, assimilation efficiencies were 91.7 +/- 3.7% for pyrene, 91.9 +/-
1.4% for BaP, 96.6 +/- 1.4% for chrysene, and 97.7 +/- 0.5% for HCBP from
suspended algae. Algal particle clearance rates for the mussels ranged from
47-143 ml/g tissue/h. Thus, zebra mussels efficiently accumulated non-polar
contaminants sorbed to algae, while a smaller fraction of the
sediment-associated contaminant was bioavailable. Furthermore, the
contaminants sorbed onto suspended sediment particles were quickly removed
from the water and deposited as pseudofeces. The pseudofeces production was
positively correlated with filtration rate and suspended particle
concentrations.
PMID: 9747518, UI: 98419655


Chem Biol Interact 1995 Jul 14;97(2):131-48
Biotransformation of benzo[a]pyrene and other polycyclic aromatic
hydrocarbons and heterocyclic analogs by several green algae and other algal
species under gold and white light.
Warshawsky D, Cody T, Radike M, Reilman R, Schumann B, LaDow K, Schneider J
University of Cincinnati, Department of Environmental Health, OH 45267-0056,
USA.
This laboratory has shown that the metabolism of benzo[a]pyrene (BaP), a
carcinogenic polycyclic aromatic hydrocarbon (PAH), by a freshwater green
alga, Selenastrum capricornutum, under gold light proceeds through a
dioxygenase pathway with subsequent conjugation and excretion. This study
was undertaken to determine: (1) the effects of different light sources on
the enzymatic or photochemical processes involved in the biotransformation
of BaP over a dose range of 5-1200 mg/l; (2) the phototoxicity of
carcinogenic PAHs and mutagenic quinones to a green alga; (3) the ability of
other algal systems to metabolize BaP. Cultures were exposed to different
doses of BaP for 2 days at 23 degrees C under gold, white or UV-A
fluorescent light on a diurnal cycle of 16 h light, 8 h dark. Under gold
light, metabolites of BaP produced by Selenastrum capricornutum were the
dihydrodiols of which the 11,12-dihydrodiol was the major metabolite. Under
white light, at low doses, the major metabolite was the 9,10-dihydrodiol.
With increasing dose, the ratio of dihydrodiols to quinones decreased to
less than two. With increasing light energy output, from gold to white to
UV-A in the PAH absorbing region, BaP quinone production increased. Of other
carcinogenic PAHs studied, only 7H-dibenz[c,g]carbazole was as phototoxic as
BaP while 7,12-dimethylbenz[a]anthracene, dibenz[a,j]acridine and
non-carcinogenic PAHs, anthracene and pyrene, were not phototoxic. The
3,6-quinone of BaP was found to be highly phototoxic while quinones that
included menadione, danthron, phenanthrene-quinone and hydroquinone were
not. The data suggest that the phototoxicity of BaP is due to photochemical
production of quinones; the 3,6-quinone of BaP is phototoxic and is probably
the result of the production of short lived cyclic reactive intermediates by
the interaction of light with the quinone. Lastly, only the green algae,
Selenastrum capricornutum, Scenedesmus acutus and Ankistrodesmus braunii
almost completely metabolized BaP to dihydrodiols. The green alga
Chlamydomonas reinhardtii, the yellow alga Ochromonas malhamensis, the blue
green algae Anabaena flosaquae and euglenoid Euglena gracilis did not
metabolize BaP to any extent. The data indicate that algae are important in
their ability to degrade PAHs but the degradation is dependent on the dose
of light energy emitted and absorbed, the dose of PAHs to which the algae
are exposed, the phototoxicity of PAHs and their metabolite(s) and the
species and strain of algae involved. All of these factors will be important
in assessing the degradation and detoxification pathways of recalcitrant
PAHs by algae.

Good luck,

Chuck Miller
--

Charles A. Miller, III, Ph.D.
Associate Professor of Environmental Health Sciences
Tulane University School of Public Health and Tropical Medicine
1430 Tulane Ave.
New Orleans, LA 70112
(504)585-6942    rellim at tulane.edu
Bionet.toxicology news group: http://www.bio.net/hypermail/toxicol/current




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