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1.
This study was conducted to investigate the toxicity of the organophosphate insecticide fenamiphos to earthworms (Eisenia fetida) under laboratory conditions. Earthworms were exposed to soils differing in their physico-chemical properties spiked with
fenamiphos at concentrations ranging from 10 to 200 mg kg−1 for a period of 4 weeks. Residues of fenamiphos and its metabolites were determined in both soils and earthworms after 4 weeks
of pesticide exposure. Fenamiphos was degraded faster in the alkaline soil than in the neutral and acidic soils. Median lethal
concentration of fenamiphos in the neutral soil was 228 mg kg−1 soil. Residues of fenamiphos caused a significant reduction in the biomass of worms, especially the ones exposed to the pesticide
in the acidic soil. In vitro experiments suggested that fenamiphos was biotransformed in the earthworms principally to its
oxide metabolite. To our knowledge, this is the first study demonstrating the biotransformation of fenamiphos by E. fetida. 相似文献
2.
Selenium effects in nature are mediated by the relatively large bioconcentration of aqueous Se by primary producers and smaller,
yet critical, dietary transfers to primary consumers. These basal processes are then propagated through food webs to higher
trophic levels. Here we quantified the movement of dissolved Se (as selenite) to periphyton, and used the resultant periphyton
as a food source for conducting full life-cycle dietary Se exposures to the mayfly Centroptilum triangulifer. Periphyton bioconcentrated Se ~2,200-fold from solution in a log-linear fashion over dissolved Se concentrations ranging
from 1.1 to 23.1 μg L−1. We examined the influence of two feeding ration levels (1x and 2x) on trophic transfer, tissue Se concentrations, maternal transfer, and functional endpoints of mayfly performance. Mayflies
fed a lesser ration (1x) displayed greater trophic transfer factors (mean TTF, 2.8 ± 0.4) than mayflies fed 2x rations (mean TTF, 1.1 ± 0.3). In 1x exposures, mayflies exhibited significant (p < 0.05) reductions in survivorship and total body mass at dietary [Se] ≥ 11.9 μg g−1, reduced total fecundity at ≥4.2 μg g−1, and delayed development at ≥27.2 μg g−1. Mayflies fed a greater ration (2x) displayed reduced tissue Se concentrations (apparently via growth dilution) relative to 1x mayflies, with no significant effects on performance. These results suggest that the influence of Se on mayfly performance
in nature may be tied to food resource availability and quality. Furthermore, nutritional status is an important consideration
when applying laboratory derived estimates of toxicity to risk assessments for wild populations. 相似文献
3.
Toxicity of lead, cadmium and mercury on embryogenesis, survival, growth and metamorphosis of Meretrix meretrix larvae 总被引:1,自引:0,他引:1
Qing Wang Baozhong Liu Hongsheng Yang Xiaoyu Wang Zhihua Lin 《Ecotoxicology (London, England)》2009,18(7):829-837
In order to assess the toxicity of heavy metals on the early development of Meretrix meretrix, the effects of mercury (Hg), cadmium (Cd) and lead (Pb) on embryogenesis, survival, growth and metamorphosis of larvae were
investigated. The EC50 for embryogenesis was 5.4 μg l−1 for Hg, 1014 μg l−1 for Cd and 297 μg l−1 for Pb, respectively. The 96 h LC50 for D-shaped larvae was 14.0 μg l−1 for Hg, 68 μg l−1 for Cd and 353 μg l−1 for Pb, respectively. Growth was significantly retarded at 18.5 μg l−1 (0.1 μM) for Hg, 104 μg l−1 (1 μM) for Cd and 197 μg l−1 (1 μM) for Pb, respectively. The EC50 for metamorphosis, similar to 48 h LC50, was higher than 96 h LC50. Our results indicate that the early development of M. meretrix is highly sensitive to heavy metals and can be used as a test organism for ecotoxicology bioassays in temperate and subtropical
regions. 相似文献
4.
The physiological responses and Cu accumulation of Paulownia fortunei (Seem) Hemsl. were studied under 15.7–157 μmol L−1 Cu treatments in liquid culture for 14 days; the impacts of Cu concentration in the seedlings were evaluated under Cu mine
tailing culture with acetic acid and EDTA treatment for 60 days. Results showed that the concentrations of Chl-a, Chl-b and Carotenoids significantly increased (p < 0.05) at 15.7–78.7 μmol L−1Cu treatment and significantly decreased at 157 μmol L−1 treatment after 14 days of Cu exposure. The activities of superoxide dismutase (SOD) and catalase (CAT) significantly increased
as Cu levels were enhanced and the activities of both SOD and CAT under 157 μmol L−1 Cu stress were 2.9 and 1.9 times higher than that of control, respectively. The concentrations of proline and soluble sugars
in the leaves of P. fortunei significantly increased as the Cu concentrations were elevated. Cu concentrations in roots, stems and leaves of P. fortunei increased significantly as Cu levels increased and reached 1911, 101 and 93 μg g−1 dry weights (DW) at 157 μmol L−1 Cu treatment, respectively. The seedlings of P. fortunei cultivated in Cu tailing experienced unsuccessful growth and loss of leaves in all treatments due to poor nutrition of the
Cu tailing. The dry weight of P. fortunei increased under all the treatments of acetic acid after 60 days exposure. However, dry weight significantly decreased under
both levels of EDTA. The Cu concentrations increased significantly in roots and decreased in leaves when each was treated
with both concentrations of acetic acid. The Cu concentrations in the roots, stems and leaves increased significantly, and
the concentrations of Cu in the stems and leaves under the treatment of 2 μmol L−1 EDTA reached 189.5 and 763.1 μg g−1 DW, respectively. The result indicated that SOD, CAT, proline and soluble sugars played an important role in coping with
the oxidative stress of copper. Acetic acid could promote growth and EDTA at the experimental levels, which could also enhance
Cu absorption and translocation into the stems and leaves of P. fortune. Furthermore, acetic acid and EDTA could be rationally utilized in Cu-contaminated soil. 相似文献
5.
Trenfield MA Ng JC Noller B Markich SJ van Dam RA 《Ecotoxicology (London, England)》2012,21(4):1013-1023
The influence of dissolved organic carbon (DOC), in the form of Suwannee River fulvic acid (SRFA), on uranium (U) toxicity
to the unicellular eukaryote, Euglena gracilis (Z strain), was investigated at pH 6. In a background medium without SRFA, exposure of E. gracilis to 57 μg L−1 U resulted in a 50% reduction in growth (IC50). The addition of 20 mg L−1 DOC (as SRFA), reduced U toxicity 4 to 5-fold (IC50 increased to 254 μg L−1 U). This reduction in toxicity was also evident at more sensitive effect levels with a 10% reduction in growth (IC10) occurring at 5 μg L−1 U in the background medium and at 17 μg L−1 U in the SRFA medium, respectively. This amelioration of toxicity with the addition of SRFA was linked to a decrease in the
bioavailability of U, with geochemical speciation modelling predicting 84% of U would be complexed by SRFA. The decrease in
bioavailability of U in the presence of SRFA was also evident from the 11–14 fold reduction in the cellular concentration
of U compared to that of E. gracilis in the background medium. Stepwise multiple linear regression analyses indicated that UO2
2+ alone explained 51% of the variation in measured U toxicity to E. gracilis. Preliminary U exposures to E. gracilis in the presence of a reactive oxygen species probe, suggest exposure to ≥60 μg L−1 U may induce oxidative stress, but this endpoint was not considered to be a sensitive biological indicator. 相似文献
6.
Yao Liu Qixing Zhou Xiujie Xie Dasong Lin Luxi Dong 《Ecotoxicology (London, England)》2010,19(8):1551-1559
Superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and the comet assay (SCGE) were used as biomarkers
to evaluate the oxidative stress and genotoxicity of toluene, ethylbenzene and xylene in earthworms (Eisenia fetida). The results indicated that the exposure of the three pollutants caused a stress response of the three enzymes, an approximate
bell-shaped change (a tendency of inducement firstly and then inhibition with increasing concentrations of the pollutants)
was mostly found. The three enzymes tested differed in their sensitivity to different pollutants. While the activity of POD
was not significantly changed within the concentration range, the concentration thresholds for significant (P < 0.05) responses to toluene based on SOD and CAT were 5 mg kg−1, respectively. Similarly, the concentration thresholds for significant (P < 0.05) responses to ethylbenzene based on CAT and POD were 10 and 5 mg kg−1, respectively, while the activity of SOD was not significantly changed within the concentration range. Significant responses
to xylene based on CAT and POD were 5 mg kg−1, respectively, while the activity of SOD was significantly (P < 0.05) induced at 10 mg kg−1. The SCGE assay results showed that these three pollutants could significantly (P < 0.01) induce DNA damage in earthworms and the clear dose-dependent relationships were displayed, indicating potential genotoxic
effects of toluene, ethylbenzene, and xylene on E. fetida. The inducement of DNA damage may be attributed to the oxidative attack of toluene, ethylbenzene, and xylene. Toluene seemed
to be more genotoxic as it could induce the higher extent of DNA damage than ethylbenzene and xylene. The results suggest
that the SCGE assay of earthworms is simple and efficient for diagnosing the genotoxicity of pollutants in terrestrial environment. 相似文献
7.
Biomarker assessment of toxicity with miniaturised bioassays: diclofenac as a case study 总被引:1,自引:0,他引:1
The development of suitable biomarker-based microbioassays with model species with ecological relevance would help increase
the cost-efficiency of routine environmental monitoring and chemical toxicity testing. The anti-inflammatory drug diclofenac
has been widely reported in the environment but ecotoxicological data are scarce. The aim of this work is to assess the acute
and chronic sublethal toxicity of diclofenac in relevant taxa of aquatic and riparian ecosystems (the fish Danio rerio and the fern Polystichum setiferum). Reliable biomarkers of cell viability (mitochondrial activity), plant physiology (chlorophyll), growth (DNA content) or
oxidative damage (lipid peroxidation) were assessed as sensitive endpoints of toxicity. DNA quantification shows that diclofenac
induces acute lethal phytotoxicity at 24 and 48 h (LOECs 30 and 0.3 μg l−1, respectively). Hormetic effects in mitochondrial activity in spores of Polystichum setiferum mask lethality, and adverse effects are only observed at 48 h (LOEC 0.3 μg l−1). In chronic exposure (1 week) LOEC for DNA is 0.03 μg l−1. Mitochondrial activity shows a strong hormetic stimulation of the surviving spore population (LOEC 0.3 μg l−1). Little changes are observed in chlorophyll autofluorescence (LOEC 0.3 μg l−1). A very short exposure (90 min) of zebrafish embryos induces a reduction of lipid peroxidation at 0.03 μg l−1. Environmental concentrations of diclofenac can be deleterious for the development of significant populations of sensitive
individuals in aquatic and riparian ecosystems. 相似文献
8.
Tolerance and accumulation of lead by species of <Emphasis Type="Italic">Iris</Emphasis> L. 总被引:1,自引:0,他引:1
Seedling development, accumulation and distribution of lead (Pb) in Iris lactea var. chinensis (Fisch.) Koidz. and I. tectorum Maxim. were studied using plants grown in sand culture and exposed to 0–10 mmol l−1 concentrations of Pb supplied as Pb(NO3)2 for 28 days. A significant reduction in dry weight (dw) of shoots and roots of I. lactea var. chinensis was observed at 6 and 10 mmol l−1, respectively, and a significant reduction in dw of shoots and roots of I. tectorum was observed at 6 mmol l−1. Concentration of Pb in the shoots and roots of I. lacteal var. chinensis exposed to 4 mmol l−1 Pb reached 1,109 μg g−1 and 2,408 μg g−1 dw, respectively. The index of tolerance (IT) of I. lactea var. chinensis among 0–8 mmol l−1 Pb treatments were not significantly different, while those of I. tectorum at 6 mmol l−1 Pb were significantly decreased. The results indicated that I. lactea var. chinensis was more tolerant to Pb than I. tectorum. Sub-cellular localization of Pb in root cells was evaluated using transmission electron microscopy (TEM) and Pb deposits
were found along the plasma membrane of some root tip cells of I. lactea var. chinensis treated at 10 mmol l−1 Pb. Deposits of Pd were also observed along the surface, in the root tip cell wall and in the cytoplasm of a few malformed
cells of I. tectorum exposed at 10 mmol l−1 Pb treatment. One possible mechanism to explain these observations may be that most cells can maintain normal activities
in the plant by sacrificing a small number of cells that accumulate a large amount Pb and show toxicity. Future studies should
be designed to test this hypothesis. 相似文献
9.
Ackerman JT Eagles-Smith CA Takekawa JY Iverson SA 《Ecotoxicology (London, England)》2008,17(8):789-801
We examined factors influencing mercury concentrations in 90 fledgling Forster’s terns (Sterna forsteri) and evaluated whether mercury influenced postfledging survival in San Francisco Bay, California. Mercury concentrations
(±SE) in chicks 21–29 days old (just before fledging) were 0.33 ± 0.01 μg g−1 ww for blood and 6.44 ± 0.28 μg g−1 fw for breast feathers. Colony site had an overriding influence on fledgling contamination, however hatching date and age
also affected blood, but not feather, mercury concentrations. Blood mercury concentrations decreased by 28% during the 50-day
hatching period and increased with chick age by 30% during the last week prior to fledging. Using radio-telemetry, we calculated
that cumulative survival during the 35-day postfledging time period was 0.81 ± 0.09 (SE). Postfledging survival rates increased
with size-adjusted mass, and cumulative survival probability was 61% lower for terns with the lowest, compared to the highest,
observed masses. Conversely, survival was not influenced by blood mercury concentration, time since fledging, sex, or hatch
date. Mercury concentrations in breast feathers of fledglings found dead at nesting colonies also were no different than those
in live chicks. Our results indicate that colony site, hatching date, and age influenced mercury concentrations in fledgling
Forster’s terns, but that mercury did not influence postfledging survival. 相似文献
10.
Lane OP O'Brien KM Evers DC Hodgman TP Major A Pau N Ducey MJ Taylor R Perry D 《Ecotoxicology (London, England)》2011,20(8):1984-1991
Environmental mercury exposure of birds through atmospheric deposition and watershed point-source contamination is an issue
of increasing concern globally. The saltmarsh sparrow (Ammodramus caudacutus) is of high conservation concern throughout its range and the potential threat of mercury exposure adds to other anthropogenic
stressors, including sea level rise. To assess methylmercury exposure we sampled blood of the northern nominal subspecies
of saltmarsh sparrows (A. c. caudacutus) nesting in 21 tidal marshes throughout most of the species’ breeding range. Blood of tree swallows (Tachycineta bicolor) was sampled concurrently at three of these sites to provide a comparison with a well-studied songbird that is a model species
in ecotoxicology. Arithmetic means (±1 SD) ranged from 0.24 ± 0.06 μg g−1 wet weight (ww) in Connecticut to 1.80 ± 0.14 μg g−1 ww in Massachusetts, differing significantly among sites. Comparison to tree swallows indicates that mercury exposure is
significantly higher in saltmarsh sparrows, making them a more appropriate bioindicator for assessing risk to methylmercury
toxicity in tidal marsh ecosystems. 相似文献
11.
Acute toxic effects and mechanisms of two typical endocrine disrupting chemicals, nonylphenols (NPs) and bisphenol A (BPA),
to the embryonic development of the abalone Haliotis diversicolor supertexta, were investigated by the two-stage embryo toxicity test. The 12-h median effective concentrations (EC50) of NPs and BPA to the trochophore development were 1016.22 and 30.72 μg L−1, respectively, and the respective 96-h EC50 values based on the completion of metamorphosis (another experimental endpoint) were reduced to 11.65 and 1.02 μg L−1. Longer exposure time and magnified exposure concentrations in the benthic diatom, that serves as both food source and settlement
substrate during the metamorphosis, via bioaccumulation, led to the higher sensitivity of metamorphosis to target EDCs compared
with the trochophore development. The hazard concentrations for 5% of the species (HC5) could be employed as the safety thresholds for the embryonic development of the abalone. The 12-h HC5 values of NPs and BPA were 318.68 and 13.93 μg L−1, respectively, and the respective 96-h HC5 values were 0.99 and 0.18 μg L−1, which were at environmentally relevant levels. Results of proteomic responses revealed that NPs and BPA altered various
functional proteins in the abalone larvae with slight differences between each chemical and affected various physiological
functions, such as energy and substance metabolism, cell signalling, formation of cytoskeleton and cilium, immune and stress
responses at the same time, leading to the failure of metamorphosis. 相似文献
12.
Genotoxicity of crude cyanobacteria extracts (CBE) from blooms in Taihu Lake, China toward common carp (Cyprinus carpio) was measured. The primary extracellular product was determined by HPLC to be Microcystin-LR (MC-LR, L for leucine and R
for arginine) with an average concentration of 2.4 × 102 μg MC g−1 dry weight of cyanobacteria. Acute toxicity to carp, expressed as the 72-h LC50, was 53 mg, dw cyanobacteria L−1. Genotoxicity, as determined by the micronucleus (MN) and comet assays were both dose- and time-depended. Deformities of
cellular organelles in liver and gill were observed by use of transmission electron microscopy (TEM). The results showed that
MC-LR from cyanobacteria from Taihu Lake could induce genotoxic response and tissue-level morphological changes in common
carp. 相似文献
13.
Myocardial amiodarone concentrations after short- and long-term treatment in patients with end-stage heart failure 总被引:2,自引:0,他引:2
R. Candinas J. Frielingsdorf H. R. Ha T. Carrel M. Turina F. Follath 《European journal of clinical pharmacology》1998,53(5):331-336
Background: Pharmacokinetics and tissue concentrations of amiodarone may vary considerably in end-stage heart failure, but may be crucial
for treatment efficiency and antiarrhythmic drug therapy.
Objective: This study was undertaken to determine plasma amiodarone and desethylamiodarone concentrations and to determine whether
they correlate with myocardial concentrations in explanted hearts from patients with end-stage heart failure.
Patients and methods: Eight patients with idiopathic dilated cardiomyopathy and normal coronary arteries were included in the present study. Myocardial
tissue samples (seven sites) and epicardial fat were taken from each explanted heart, and drug concentrations of amiodarone
and desethylamiodarone were determined. In addition, plasma drug levels were measured and compared with the myocardial amiodarone/desethylamiodarone
concentrations.
Results: The mean cumulative amiodarone dose was 91 g and the mean plasma concentrations of amiodarone and desethylamiodarone were
0.68 and 0.84 μg · ml−1, respectively. The tissue concentrations of amiodarone amounted to 13.2 and 28.3 μg · g−1, respectively, in the atria and to 13.0 and 40.8 μg · g−1, respectively, in the ventricles. The distribution of the drug and its metabolite were similar in the right and left ventricles.
There was a good correlation between myocardial concentration of amiodarone and desethylamiodarone and the cumulative ingested
dose of amiodarone. Tissue drug concentrations correlated only poorly with plasma amiodarone or desethylamiodarone levels.
The highest drug levels were measured in the epicardial fat tissue, where the ratio of amiodarone 105 μg · g−1 to desethylamiodarone 32 μg · g−1 was reversed (3.3 compared with 0.29 in the ventricles). Thus, amiodarone concentrations in epicardial fat were approximately
10 times higher than myocardial and 150 times higher than plasma levels.
Conclusions: Our data confirm the slow equilibrium of amiodarone and desethylamiodarone concentrations between plasma and myocardium.
Myocardial tissue concentrations of desethylamiodarone and, to a lesser degree, amiodarone correlate with the cumulative ingested
dose of amiodarone. Monitoring of the total cumulative dose may be more relevant clinically than monitoring plasma levels.
These results support the clinical practice of reducing the maintenance dose of amiodarone in patients who are on long-term
treatment.
Received: 12 July 1997 / Accepted in revised form: 25 September 1997 相似文献
14.
Oluseye K. Onajole Xoliswa V. Belewa Yacoob Coovadia Thavendran Govender Hendrik G. Kruger Glenn E. M. Maguire Dianithi Naidu Benesh Somai Nisha Singh Patrick Govender 《Medicinal chemistry research》2011,20(8):1394-1401
The antimicrobial activity of five novel SQ109 derivatives including SQ109 against bacteria, yeast and filamentous fungi is reported herein. Using broth microdilution techniques, compounds 2 and 3 were found to be active against most tested fungi and bacteria, with minimum inhibitory concentrations (MICs) ranging from
0.98 to 31 μg ml−1, except for Klebsiella pneumonia where the MIC was 250 μg ml−1. SQ109 and derivative 4 did not show any significant activity against most of the organisms used. However, their reduced derivatives 1 and 5 showed promising activity with MICs between 0.49 and 62.5 μg ml−1 against most of the microorganisms used. 相似文献
15.
Han T Kong JA Kang HG Kim SJ Jin GS Choi H Brown MT 《Ecotoxicology (London, England)》2011,20(8):2056-2068
The sensitivity of early life stages of the brown seaweed Saccharina japonica to six metals (Cd, Cu, Hg, Ni, Pb, Zn) and two waste-water samples were investigated and a new toxicity bioassay developed.
The two endpoints used were spore germination and germ tube elongation with an exposure time of 24 h. Optimal test conditions
determined for photon irradiance, pH, salinity and temperature were darkness, pH 8, 35‰ and 15°C, respectively. The toxicity
ranking of five metals was: Hg (EC50 of 41 and 42 μg l−1) > Cu (120 and 81 μg l−1) > Ni (2,009 and 1,360 μg l−1) > Zn (3,024 and 3,897 μg l−1) > Pb (4,760 and 4,429 μg l−1) > Cd (15,052 and 7,541 μg l−1) for germination and germ tube elongation, respectively. The sensitivities to Cd, Cu and Ni were greater in germ tube elongation
than in germination process. When tested against two different waste-water samples (processed animal and printed circuit board
waste-water) values of EC50 were between 21.29 and 32.02% for germination and between 5.33 and 8.98% for germ tube elongation. Despite differences in
their chemical composition, the toxic effects of waste-water samples, as indicated by EC50 values, did not differ significantly for the same endpoints. The CV range for both germination and germ tube elongation was
between 4.61 and 37.69%, indicating high levels of precision of the tests. The results compare favourably with those from
more established test procedures employing micro- and macroalgae. The advantages and potential limitations of the bioassay
for the assessment of anthropogenic impacts on coastal ecosystems and commercial cultivation areas in near-shore environments
are discussed. 相似文献
16.
17.
Emadeldeen Hassan Mohammed Guizhong Wang Jielan Jiang 《Ecotoxicology (London, England)》2010,19(5):911-916
Lethal and sublethal toxicity of Nickel (Ni) to three marine copepods Tigriopus japonicus, Apocyclops borneoensis and Acartia pacifica was investigated. The 48-h LC50 values were 17.70, 13.05 and 2.36 mg l−1 Ni, respectively. A. pacifica was found to be the most sensitive to Ni in acute exposure tests. In order to assess sublethal effects of Ni on copepod reproduction,
the test organisms were exposed to four nominal Ni concentrations 0, 10, 100, 1000 μg l−1 Ni. The results indicated that offspring production of T. japonicus and A. borneoensis was significantly reduced after exposure to 10 μg l−1 Ni. Whereas egg production and egg hatching success of A. pacifica were significantly reduced at 100 and 10 μg l−1 Ni, respectively. Exposure of copepods to the highest Ni concentration caused a severely reduced nauplii production from
T. japonicus, A. borneoensis and A. pacifica by 87.8, 56.9 and 65.8%, respectively, and a significantly reduced egg production of A. pacifica by 74.4%. These results show that Ni excess in the coastal environment can have detrimental effects on reproduction of copepods. 相似文献
18.
Yingang Xue Xueyuan Gu Xiaorong Wang Cheng Sun Xianghua Xu Jian Sun Baogang Zhang 《Ecotoxicology (London, England)》2009,18(6):693-699
Biochemical effects of tetrabromobisphenol A (TBBPA) on the earthworm Eisenia fetida, including superoxide dismutase, catalase, glutathione-S-transferase, reduced glutathione, oxidized glutathione, GSH/GSSG ratio and malondialdehyde (MDA) level, were measured to
assess ecological toxicity of TBBPA. With OECD standard filter-paper contact test method, earthworms were exposed to TBBPA
of a range of concentrations (0.00, 0.01, 0.05, 0.1, 0.5 and 1.0 mg L−1). According to the electron paramagnetic resonance spectrum, reactive oxygen species (ROS) generated in the earthworm was
identified as the hydroxyl radical (•OH) which was significantly induced at all TBBPA concentrations. With the increasing of TBBPA concentration, the antioxidant
enzymes, glutathione and MDA levels varied significantly. The results showed that TBBPA exerts its toxic effects on E. fetida by inducing the generation of ROS and resulting in oxidative damage. The results show that the •OH production leads to oxidative stress in the tissues of the earthworm E. fetida. 相似文献
19.
The effects of a commercially available anionic surfactant solution (FFD-6) on growth and morphology of a common green alga
(Scenedesmus obliquus) and on survival and clearance rates of the water flea Daphnia magna were studied. The surfactant-solution elicited a morphological response (formation of colonies) in Scenedesmus at concentrations of 10–100 μl l−1 that were far below the No Observed Effect Concentration (NOEC) value of 1,000 μl l−1 for growth inhibition. The NOEC-value of FFD-6 for colony-induction was 3 μl l−1. Daphnia survival was strongly affected by FFD-6, yielding LC50–24h and LC50–48h of 148 and 26 μl l−1, respectively. In addition, clearance rates of Daphnia feeding on unicellular Scenedesmus were inhibited by FFD-6, yielding a 50% inhibition (EC50–1.5h) at 5.2 μl l−1 with a NOEC of 0.5 μl l−1. When Daphnia were offered FFD-6-induced food in which eight-celled colonies (43 × 29 μm) were most abundant, clearance rates (~0.14 ml
ind.−1 h−1) were only 25% the rates of animals that were offered non-induced unicellular (15 × 5 μm) Scenedesmus (~0.56 ml ind.−1 h−1). As FFD-6 concentrations in the treated food used in the experiments were far below the NOEC for clearance rate inhibition,
it is concluded that the feeding rate depression was caused by the altered morphology of the Scenedesmus moving them out of the feeding window of the daphnids. The surfactant evoked a response in Scenedesmus that is similar to the natural chemically induced defensive reaction against grazers and could disrupt the natural information
conveyance between these plankton organisms. 相似文献
20.
Slavica B. Ilić Sandra S. Konstantinović Dragiša S. Savić Vlada B. Veljković G. Gojgić-Cvijović 《Medicinal chemistry research》2010,19(7):690-697
A media consisting of isatin-Schiff bases (isatin-3-thiosemicarbazone, isatin-3-semicarbazone, and isatin-3-phenylhydrazone)
was developed to maximize the production of antibiotics Hexaene H-85 and Azalomycine B by Streptomyces hygroscopicus. The media isatin-3-thiosemicarbazone resulted in the maximum antibiotics concentration of 372 μg cm−3 for Hexaene H-85 and 118 μg cm−3 for Azalomycine B. The impact of modified media on soil morphology also was investigated. 相似文献