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1.
The growth of Chlorella marine, Nannochloris oculate, Pyramimonaos sp., Platymonas subcordiformis and Phaeodactylum tricornutum exposed to chlorobenzene, 1,2-dichlorobenzene, 1, 2, 3, 4-tetrachlorobenzene and pentachlorobenzene was tested. The Boltzman equation was used to describe organism growth. The time course for uptake of hydrophobic organic chemicals (HOCs) by aquatic organisms was expressed by incorporating growth and, if desired, the effect of metabolism into the HOC bioconcentration process. The probability of any given concentration of HOCs in the organisms causing a specified toxic endpoint was expressed with a modified Weibull distribution function. The combined bioconcentration and probability equations were tested with data for time course of incubation of algae exposed to chlorinated benzenes (CBs). A set of parameters, including the uptake rate constant k1, the elimination rate constant k2 and thereafter the bioconcentration factor on a dry weight basis, BCFD, the critical HOC concentration in the organism resulting in a specified toxic endpoint, C*A, and the spread factor, S, could be obtained by fitting only experimental data for percent growth inhibition(%)-time-CB exposure concentration. The average coefficients of variation within CBs were 15.2% for BCFD, 21.0%for k1, 18.3% for k2, 8.1% for C*A and 9.7% for S. The variability in toxicity (such as EC10, EC50, ECg0) derived from the model equations agreed well with those experimentally observed. 相似文献
2.
The growth of Chlorella marine, Nannochloris oculate, Pyramimonaos sp., Platymonas subcordiformis and Phaeodactylum tricornutum exposed to chlorobenzene, 1,2-dichlorobenzene, 1,2,3,4-tetrachlorobenzene and pentachlorobenzene was tested. The Boltzman
equation was used to describe organism growth. The time course for uptake of hydrophobic organic chemicals (HOCs) by aquatic
organisms was expressed by incorporating growth and, if desired, the effect of metabolism into the HOC bioconcentration process.
The probability of any given concentration of HOCs in the organisms causing a specified toxic endpoint was expressed with
a modified Weibull distribution function. The combined bioconcentration and probability equations were tested with data for
time course of incubation of algae exposed to chlorinated benzenes (CBs). A set of parameters, including the uptake rate constant
k
1, the elimination rate constant k
2 and thereafter the bioconcentration factor on a dry weight basis, BCF
D, the critical HOC concentration in the organism resulting in a specified toxic endpoint, C
A
*
, and the spread factor, S, could be obtained by fitting only experimental data for percent growth inhibition(%)-time-CB exposure concentration. The
average coefficients of variation within CBs were 15.2% for BCF
D, 21.0% for k
1, 18.3% for k
2, 8.1% for C
A
*
and 9.7% for S. The variability in toxicity (such as EC10, EC50, EC90) derived from the model equations agreed well with those experimentally observed. 相似文献
3.
This study investigated the cytotoxicity of gemcitabine using the marine ciliate Euplotes vannus as the test organism.The median lethal concentrations(LC50 values)were determined using acute toxicity tests within an exposure time of 30 min with 0,6,12,24,and 48 mg mL^-1 gemcitabine.The median inhibition effect(IC50 value)on the growth of the ciliate cells was examined using chronic toxicity tests within 5 days(120 h)after exposure for 30 min with 0,0.7,3.5,7,and 14 mg mL^-1 gemcitabine.The 30-min LC50value was 10.66-mg mL 1.The LC50 values decreased with increasing exposure times and well fitted to the toxicity curve equation LC50=10.93+28.4e^-0.19t(R2=0.93;P<0.05,t=exposure time).The IC50 value for growth rates was 7.05 mg mL^-1,and the inhibition effect on growth rates well fitted to the model equation r%=0.8681e^-0.0782Cgem(r%means growth rate with inhibition by gemcitabine,Cgem means concentrations of gemcitabine,R^2=0.99 and P<0.05).The LC50 values of a wide range of gemcitabine concentrations could therefore be predicted for any given exposure time.These results suggest that the clinical dose of gemcitabine(20 mg mL^-1)was higher than the 30-min LC50 value,which was almost the same as the 6-min LC50 value(19.88 mg mL^-1)for E.vannus cells.The results also demonstrate that E.vannus can be used as a robust test organism for bioassays of chemotherapeutic drugs during short exposure periods. 相似文献
4.
This paper reports the photochemical degradation of Methylene Blue(MB)in natural seawater(NSW).The photodegradation reaction conformed to the first-order reaction kinetics with the rate constant 0.0158 min-1.MB was photochemically degradated faster under high-pressure mercury lamp(HPML)than under sunlight.When MB was in lower concentrations,salinity could inhibit the photoreaction whereas MB in higher concentration,salinity could accelerate the photoreaction.Humid acid could also inhibit the photoreactions.Toxicity tests with marine phytoplankton Skeletonema costatum(Sk)and Heterosigma akashiwo Hada (Ha)showed decreased acute toxicity after photodegradation. 相似文献
5.
To study population dynamics of marine ciliates in different artificial seawaters (ASW), the population growth dynamics of a common marine ciliate Euplotes vannus were investigated using beef extract media and rice media for five types of ASW and natural seawater (NSW). The results show that: (1) the population growth rate was in the order of NSW>Flack ASW>Nakamula ASW>Schmadz ASW>Oshima ASW>Subow ASW and was considerably higher in rice media than in beef extract media (apart from Subow ASW); (2) the maximum density of E. vannus in stationary phase in each treatment was ranked as Flack ASW>Nakamula ASW>Schmadz ASW>NSW>Oshima ASW>Subow ASW, and was again higher in rice media than in beef extract media (except for Subow ASW); (3) the exponential and stationary phases were longer in rice media than in beef extract media; (4) strains of E. vannus that had been domesticated for >1 year in ASW grew significantly slower, with lower maximum density and longer stationary phase than those isolated and maintained in NSW. It was demonstrated that: (1) E. vannus may grow well in Flack, Nakamula and Schmads ASW compared with NSW (mainly in terms of growth rate); and (2) Oshima ASW is the preferred choice for stock cultures of E. vannus, but the ASWs Flack, Nakamula and Schmadz are preferred for mass culture. These findings suggest that these three ASWs are effective for the cultivation of marine protozoa for experimental studies on ecology, toxicology and molecular biology. 相似文献
6.
TOXICITY OF CHLORINATED BENZENES TO MARINE ALGAE 总被引：3，自引：0，他引：3
Towhomcorrespondenceshouldbeaddressed.ImODUcr0NMarinealgaearethemosttwortantprimaryproducersandplayanimPortantroleindetenniningthefateofpersistenthydrophobicorganicchdricaIs(HOCs)inthernarineeresySteIn.TheirhydrophobicnatureresultsinanenhanedassociationwithH0Csintheanwatercolurnn(Swackhameretal.,l993).HOCfateisdowhnatalbytwoproanes,verti-caltransporttobottomsedimentSbydeadCellsandtIansportintothefood-webbyrooplanktongraring.TherelativetoortanceofthetwoproassesdependsonprharyproduCtion… 相似文献
7.
INTERACTIONS BETWEEN AMMONIUM UPTAKE AND NITRATE UPTAKE BY NATURAL PHYTOPLANKTONASSEMBLAGES 总被引：4，自引：0，他引：4
焦念志 《中国海洋湖沼学报》1993,11(2):97-107
Measurements of ammonium and nitrate uptakes by natural phytoplankton assemblages from Jiaozhou Bay at various combinations of ammonium and nitrate concentrations with 15N trace techniques showed that uptake rate of either nitrogen was influenced by the presence of the other but that the influence of ammonium on nitrate uptake was much greater than, that of nitrate on ammonium uptake. The influence mechanism of ammonium on nitrate uptake manifested as competition at lower concentrations and as inhibition at higher concentrations (ammonium concentration >0.6 umol/L), but no total inhibition appeared within the concentration.range of the experiments (0-10umol/L). The influence of nitrate on ammonium uptake seems to be a result of competition for uptake sites on the cell surface. In view of the in situ nutrient concentration in the given marine . environment, it is believed that both nitrogen sources are utilized by phytoplankton. Nitrate uptake in the presence of ammonium and ammonium uptake in the presen 相似文献
8.
Qiang Li Shu-hong Li Wen-li Huang Cheng-yi Liu Chuan Xiong Xiao-lin Li Lin-yong Zheng 《山地科学学报》2016,13(11):2046-2052
Fruiting bodies (500 g per site) of Tricholoma matsutake and the surface layer of soils collected from 20 spatially distant areas with pristine backgrounds across China were analyzed for potassium, magnesium, calcium, zinc, iron, copper, manganese and cadmium using inductively coupled plasma optical emission spectroscopy. In terms of the bioconcentration and bioexclusion concept, K, Mg, Zn, and Cu were highly bioconcentrated, and their bioconcentration factor values varied between 75-615, 2-107, 38-603 and 7-76, respectively, across the 20 sites. Fe, Mn and Cd were moderately bioconcentrated and their bioconcentration factors (BCFs) varied between 0.6-34.0, 0.4-37.0 and 0.9-7.0 respectively. However, Ca was excluded (BCF<1). T. matsutake is a species that is harvested in the wild as a valuable food and can contain a wide spectrum of both essential and hazardous mineral compounds that accumulate at elevated concentrations even if grown in pristine areas. The estimated intake rate of Cd in the fruiting bodies indicates cause for concern associated with this metal resulting from the daily consumption of between 200 and 400 g of fruiting bodies on a frequent basis during the mushrooming season. 相似文献
9.
As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP),diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP,DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of 1-1. diversicolor supertexta can be used to indicate toxicity of the PAEs. 相似文献
10.
LAS degradation rate in Donghu Lake water under aerobic was much faster than under anaerobic condition. The half life of LAS
in aerobic and anaerobic environment was 3.2 days and 57 days, respectively. The degradation rate at 25–27°C was approximately
20 times higher than that at 1.5–3.5 °C. In a laboratory model aquatic ecosystem, two stages of bioconcentration in fish,
daphnia and snail were observed. The first stage, on second day exposure, resulted from accumulation of intact LAS, and the
second stage, on 16th day exposure, was due to metabolites. The bioconcentration factor (BCF) of LAS was extremely low in
the muscle of hybrid carp (0.64), but rather high (2485) in the gall bladder.
This cooperation project between the Institute of Hydrobiology, Academia Sinica, Wuhan, P. R. China and the Institut fur Okologische
Chemie der Gesellschaft fur Strahlen und Umweltforschung, F. R. Germany, was supported by the Natural Science Foundation P.
R. China and GSF. 相似文献
11.
《山地科学学报》2016,(11)
Fruiting bodies(500 g per site) of Tricholoma matsutake and the surface layer of soils collected from 20 spatially distant areas with pristine backgrounds across China were analyzed for potassium,magnesium,calcium,zinc,iron,copper,manganese and cadmium using inductively coupled plasma optical emission spectroscopy.In terms of the bioconcentration and bioexclusion concept,K,Mg,Zn,and Cu were highly bioconcentrated,and their bioconcentration factor values varied between 75-615,2-107,38-603 and 7-76,respectively,across the 20 sites.Fe,Mn and Cd were moderately bioconcentrated and their bioconcentration factors(BCFs) varied between 0.6-34.0,0.4-37.0 and 0.9-7.0 respectively.However,Ca was excluded(BCF1).T.matsutake is a species that is harvested in the wild as a valuable food and can contain a wide spectrum of both essential and hazardous mineral compounds that accumulate at elevated concentrations even if grown in pristine areas.The estimated intake rate of Cd in the fruiting bodies indicates cause for concern associated with this metal resulting from the daily consumption of between 200 and 400 g of fruiting bodies on a frequent basis during the mushrooming season. 相似文献
12.
This paper deals with the bioconcentration of14C-simetryne from water by aquatic test organisms: green algae—Monoraphidium minutum, rotifers—Brachionus rubens, daphnids—Daphnia magna, and fish—Brachydanio rerio. The chemical was bioconcentrated rapidly in all test species during the first 48 hours of experiment. The BCF values (bioconcentration
factor) from all uptake studies show that simetryne has higher accumulation in algae than in rotifers, daphnids and zebra
fish.
The logarithm of the n-octanol/water partition coefficient of simetryne measured as 2.06±0.05 was correlated with the BCFs
in the organisms as based on the lipid contents.
14C-simetryne uptake via the food-chain amounted to only 22% to 42% of the bioconcentration from water. Clearance of14C-derived residues from fish was rapid with a half-life of 2.1 days.
This project is a part of a cooperation program between the Institute of Hydrobiology, Academia Sinica, Wuhan, and the Institut
fur Okologische Chemie, GSF, F. R. Germany, and is supported by the Natural Science Foundation of Academia Sinica. 相似文献
13.
【目的】综述重金属元素镉Cd和铜Cu对海洋浮游植物的毒性效应研究,总结重金属对海洋浮游植物的毒性作用机制,为开展重金属对海洋浮游植物毒害机理的深入研究提供借鉴。【方法】以毒理实验中常用的重金属镉和铜为代表,总结了重金属对海洋浮游植物毒理研究的常用测试指标,归纳了重金属对海洋浮游植物光合作用、抗氧化系统等方面的毒性作用机制。【结果】重金属对海洋浮游植物毒性作用机制概括为:1)重金属替换与其结构相似的作为酶辅助因子的金属元素,使浮游植物体内某些酶失活;2)重金属直接或间接诱导活性氧的产生,使浮游植物受到氧化胁迫;3)重金属与生物大分子中的某些基团亲和性高而结合,阻断相关的生理生化过程。【结论】重金属的毒性效应因浮游植物种类不同而有所差异,今后相关研究中需更加关注重金属在多种海洋浮游植物共存环境下的毒性效应及机制,将有助于全面系统地理解重金属对海洋浮游植物的致毒机理。 相似文献
14.
NANChunrong DONGShuanglin 《中国海洋大学学报(英文版)》2004,3(1):56-59
Short-term uptake experiments and long-term semicontinuous culture experiments were performed under the condition of phosphorus (P) limitation to estimate and compare the P uptake and growth kinetics of the microalga Tetraselmis subcordiformis and the macroalga Ulva pertusa. Two new parameters, the maximum specific uptake rate (Vm^sp) and the maximal growth efficiency (β), are introduced to achieve uniformity for the comparison of nutrient uptake and growth efficiency between microalgae and macroalgae. T. subcordiformis possesses 3 times lower half saturation uptake constant, 4 times higher maximal growth rate and 20 times higher maximum specific uptake rate than U. pertusa, while U. pertusa possesses 4 times higher maximal growth efficiency than T. subcordiformis. 相似文献
15.
XU Henglong) ) SONG Weibo) ZHU Mingzhuang) QIU Yantao) and MA Honggang ) The Lab of Protozoology KLMEM Ocean University of China Qingdao P.R.China ) Department of Biology Liaocheng University Liaocheng P.R.China 《中国海洋大学学报(英文版)》2005,4(1)
1Introduction Red tides occur in recorded history,but in recentyears there is a global increase in the number of theseevents due to coastal pollution and other unclear fac-tors.Some kinds of red tides cause mass deaths of cul-tured animals and thus cause heavy economic losses forcoastwise mariculture(Nakanishi et al.,1996;Changet al.,1998;Zhu et al.,1998;Tada et al.,2001).The investigation on red tide control,however,rem-ains insufficient(Burkholder,1998;Edwards and Clark,1999).Although man… 相似文献
16.
The ratio of nitrogen/phosphorus (N/P) is known to affect cell proliferation of some marine micro algae. We evaluated the effect of N/P ratios on the proliferation and succession of phytoplankton using five marine micro algae species. We used two sources of nitrogen, NH4Cl (N1) and urea (N2), and a single source of phosphorous, NaH2PO4(P). The optimal N/P ratio that differed among the five species was affected by the source of nitrogen, being as follows (N1/P, N2/P in order): Thalassiosira sp. (30/1, 20/1),... 相似文献
17.
As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs).
In the present study, the toxicity of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl)
phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos
died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch.
In embryo toxic test, embryos incubated at the highest concentration of DMP, DEP and DBP solutions showed significantly high
abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in
all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control.
Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP.
Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos
of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.
Supported by National Natural Science Foundation of China (No. 40476057) 相似文献
18.
1IntroductionThe Tibet plateau consists of terranes which were accreted in a southward-younging succession from Late Permian to Mid-Eocene (Dewey etal., 1988; Mattern etal., 1998; Mattern and Schneider, 2000). The Songpan-Ganzi terrane was accreted to the Kunlun during Late Permian along Kunlun-Qin-ling suture. The Qiangtang block was added onto the Songpan-Ganzi terrane at the Jinsha suture dur-ing Late Triassic-Early Jurassic. The Lhasa block became attached to the Qia… 相似文献
19.
The transfer processes of organic pollutants during sewage - seawater mixing were simulated in three different mixing systems. The release rate of organic matter from sewage particles to seawater was found to be about 0.02-0.04d-1 . The release processes can be simulated by an exchange-equilibrium kinetic model. Degradation of COD was observed in all three mixing systems and can be described by a first order kinetic equation. The degradation rate constant k ranged between 0.04 and 0.07 d . These results have provided important parameters for estimation of environmental capacity. 相似文献
20.
A laboratory experiment was conducted to assess the bioaccumulation of Pb2 and its effects on growth,morphology andpigment contents of Spirulina (Arthrospira) platensis.The specimen cultured in Zarrouk liquid medium was treated with variousinitial metal concentrations (0,5,10,30,50 and 100 μgmL-1).The growth of S.platensis was adversely affected by Pb2 at high con-centrations (30,50 and 100 μg mL-1).However,at low concentrations (5 μg mL-1),Pb2 could stimulate its growth slightly.The pig-ment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner.The highest reductions (67% and 53%respectively in chlorophyll α and β carotene) were observed in 100 μg mL-1 treatment group.The LC50 (96 h) of Pb2 was measured as75.34μg mL-1.Apart from a few cases of filament breakages at elevated concentrations (50 and 100μg mL-1),morphological abnor-malities are not specific.Metal bioaccumulation increased with Pb2 concentrations,but decreased with exposure time.The maxi-mum accumulated amount was 188 mgg-1 dry weight.The bioconcentration factor (BCF) reached to a peak at day 2,followed by agradual reduction for all the exposure concentrations.S.platensis is able to tolerate considerably high Pb2 concentrations.Conse-quently it can be used as a potential species to remove heavy metal from contaminated waters. 相似文献