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1.
The composition of bound amino acids was studied in selected types of green and blue-green plankton algae by means of a new elaborated method, using paper chromatography at the triple development of the chromatogram in the set-up: butanol: acetic acid: water at the rate of 4 : 1 : 5. Algologically and bacterially pure cultures of the green algae Ankistrodesmus falcatus, Haematococcus pluvialis, Chlorella pyrenoidosa, Pediastrum boryanum, Scendesmus obliquus and of the blue-green algae Anacystis nidulans, Microcystis pulverea and Microcystis aeruginosa were cultivated in inorganic and in organic medium. The contents of amino acids in green algae were qualitatively and quantitatively evaluated in relation to their physiologic condition (phase of logarithmic growth, phase of stagnation) and to the method of nutrition. The results were compared with the contents of amino acids in blue-green algae obtained in monocultures from freshwater at blue-green algae water blooms. The composition of bound amino acids was studied in selected types of green and blue-green plankton algae by means of a new elaborated method, using paper chromatography at the triple development of the chromatogram in the set-up: butanol: acetic acid: water at the rate of 4 : 1 : 5. Algologically and bacterially pure cultures of the green algae Ankistrodesmus falcatus, Haematococcus pluvialis, Chlorella pyrenoidosa, Pediastrum boryanum, Scendesmus obliquus and of the blue-green algae Anacystis nidulans, Microcystis pulverea and Microcystis aeruginosa were cultivated in inorganic and in organic medium. The contents of amino acids in green algae were qualitatively and quantitatively evaluated in relation to their physiologic condition (phase of logarithmic growth, phase of stagnation) and to the method of nutrition. The results were compared with the contents of amino acids in blue-green algae obtained in monocultures from freshwater at blue-green algae water blooms. The following amino acids were found in the organismus of primary production: alanine, aspartic acid, arginine, cysteine, glutamic acid, histidine, isoleucine, leucine, lysine, proline, serine and glycine, threonine, tryptophane, tyrosine and valine. The following amino acids were predominant from the quantitative aspect: glutamic acid, threonine and serine and glycine. The composition of amino acids in green algae cultivated in an inorganic medium did not differ significantly from cultures cultivated in an organic medium. Differences in the quantitative composition of the individual amino acids were ascertained with green algae in relation to their physiologic condition.  相似文献   

2.
The metabolism of inorganic mercury has been studied in stationary cultures of planktonic algae Chlorella kessleri, Scenedesmus obliquus and Microcystis incerta that were exposed for 14 days to the concentration of 2 × 10?7 M of Hg(II). Individual chemical forms of mercury were determined in algae and in the culture medium at regular intervals. All the studied phytoplankton species started to metabolize mercury immediately after its application, with the exception of the blue-green alga Microcystis incerta. The accumulation of mercury proceeds without interruption till the end of the experiment. After a 14 days cultivation about 60… 80% of added mercury was present in algal cells and the portion of mercury washable from the cell surface did not exceed 2%. It was found that more than 99,5% of mercury in cultivation medium and more than 99,5% of mercury in algae was present in the form of Hg(II). A transformation of inorganic mercury to methyl-, or phenyl-mercury due to the action of algae was not observed.  相似文献   

3.
Biotransformation of phenyl and methyl mercury chloride was studied in experiments with planktonic algae Chlorella kessleri, Scenedesmus obliquus and blue-green algae Microcystis incerta. To algal cultures cultivated in an inorganic medium the labelled phenyl or methyl mercury hydroxide was added separately in the phase of the logarithmic growth, the resultant concentration being 3.2 × 10?7 M. In intervals of 0, 1, 3, 7, 10 and 14 days samples of the algae and medium were analysed for the total amount of mercury and for the presence of phenyl or methyl mercury. It was found that both methyl and phenyl mercury had accumulated very rapidly in the algae and that up to 70% of 203Hg added was present in the algae during the first 72 hours of the experiment. From the 2nd day onwards, however, methyl and phenyl mercury changed rapidly into inorganic mercury so that by the end of the experiment almost all of the mercury present in algae and the medium was in the form of inorganic mercury.  相似文献   

4.
实时荧光定量PCR方法检测南太湖入湖口产毒微囊藻   总被引:2,自引:0,他引:2  
南太湖入湖口产毒微囊藻的丰度对于周边县市取水口的水质安全和太湖水质有着重要影响.以藻毒素合成酶基因mcyE/ndaF为靶基因,建立实时荧光定量PCR检测产毒微囊藻的方法,并对南太湖入湖口7个监测点水样中产毒微囊藻的丰度进行检测,结果表明:该实时荧光定量PCR方法的特异性强及准确性、重复性较好.建立铜绿微囊藻(Microcystis aeruginosa)的标准曲线方程为y=-3.454x+49.88,斜率为-3.454,R~2=0.991,扩增效率E为94.6%,定量检测区间为1.689×10~4~1.689×10~8拷贝数/μl.对南太湖入湖口7个监测点检测表明,夹浦和合溪2个监测点的产毒微囊藻数量最高,预测产毒微囊藻浓度分别为(1.99±0.35)×10~5和(1.47±0.23)×10~5cells/ml.7个监测点的产毒微囊藻的种类较为一致,均为铜绿微囊藻.该方法可以快速准确地检测水体中微囊藻毒素产毒藻种种类和数量,为蓝藻水华监测、预警提供技术依据.  相似文献   

5.
Analyses of water flowing through coquina showed exclusion of atmospheric CO2 and supersaturation in respect to calcite and hydroxyapatite. Extensive populations growing on the walls and benefiting from these nutrients included mainly blue-green algae, green algae and diatoms.  相似文献   

6.
The radium cumulation in Coelastrum cambricum, Scenedesmus obliquus and Microcystis pulverea was studied under conditions of continuous cultivation at constant level of radium in the cultivation medium. The algae were exposed to the concentrations of 30, 300 and 3000 Bq/l 226Ra in the medium for a period of 14 days. It was found that radium started to cumulate immediately after its addition to the culture just as in the stationary type of cultivation, in the continuous cultivation, however, its content decreased with the length of exposure. This is due to the decreasing part of radium adsorbed on the cell surface. While in green algae the portion of radium incorporated into cells increased with the length of exposure, in blue-green algae up to 90% of radium was bound to the surface or gelatinous capsules of the cells through out the experiment. With the three phytoplankton species used, the highest cumulation of radium (nonwashable part) was recorded in Coelastrum cambricum. A dependence of the radium cumulation on its content in the medium was observed in the species Scenedesmus obliquus.  相似文献   

7.
宋挺  张军毅  李旭文  朱家民  胡俊 《湖泊科学》2022,34(4):1384-1391
随着全球气候变化和水体富营养化,在过去几十年中蓝藻水华改变了全球的淡水生态系统.蓝藻因独有的藻蓝蛋白而大多呈现蓝绿色,因此其水华也常称为蓝绿藻水华.然而随着蓝藻水华关注度的不断提升,尤其是监测和研究的不断深入,经常在水体中发现蓝藻水华出现黄化的现象.例如,太湖出现的黄色蓝藻水华,冬春季以长孢藻属(Dolichospermum)水华为主,夏秋季以微囊藻属(Microcystis)水华为主.即使外观看起来是蓝绿色的蓝藻水华,但仔细观察形成蓝藻水华的群体颗粒,也有部分呈现黄色,反之亦然.实际上,鉴于色素组成的差异性,也许水体中就没有两个颜色完全一致的蓝藻群体颗粒.目前对于黄色的蓝藻水华及其形成机理,国内外鲜有报道和研究.光照和氮限制被认为是最有可能的原因.在关注蓝藻水华黄化的同时,更应该关注和研究这些颜色变化给蓝藻水华及水环境所带来的风险和挑战,尤其是对水生态管理工作的启发和意义.  相似文献   

8.
The LC50 of Malathion for Channu punctatus is determined for 24… 96 h of exposure as 10.95… 3.22 mg/l. At exposure to 2.5 mg./l Malathion, growth–measured by increase in weight–is significantly reduced from the 19th day and reduced by 10 % till the 31st day. During the same period of time, the RNA and protein contents of the muscle is lowered by 10 and 15 %, respectively, as compared with the control. In addition to an acute toxic effect, in sublethal concentrations Malathion has also pronounced effects on growth and metabolism.  相似文献   

9.
Nested structure of plankton communities from Chilean freshwaters   总被引:1,自引:1,他引:0  
1. Nestedness has been recognized as a characteristic pattern of community organization. In a nested metacommunity, species-poor sites are proper subsets of relatively richer sites, implying that the conservation of many poor habitats can be ineffective.
2. Here we compiled the last 30 years of published limnological research on Chilean lakes, in order to determine whether or not species distribution of freshwater plankton communities exhibit a nested structure, and which habitat features best explain the observed biogeographic order.
3. We built presence–absence matrices for diatoms, green algae, blue-green algae, cladocerans, copepods, rotifers, as well as for the grouped phytoplankton and zooplankton. For each matrix, we calculated their degree of nestedness and tested whether or not they differ from matrices assembled according to two alternative null models. From nestedness results, we identified a minimal set of lakes that contain 75% of the regional species pool. After that, we evaluated whether nestedness is maintained when the community structure is organized according to latitude, altitude, area and isolation of lakes.
4. Our analyses reveal that total phytoplankton, total zooplankton, as well as diatom, cladoceran, copepod, and rotifer assemblages of Chilean lakes are not randomly assembled but highly nested. Conversely, green and blue-green algae did not show a clear nested structure. A few sites (3–5) ranked by nestedness for each taxonomic group, covered 75% of the species pool. Finally, we found that surface area and isolation of lakes were the two variables more likely to affect nestedness.
Keywords: Zooplankton; Phytoplankton; Limnology; Chile; Biogeography; Nestedness  相似文献   

10.
Some aspects of the influence of copper speciation on toxicity for blue-green algae are reviewed. The experimental part concentrates on Oscillatoria redekei and Aphanizomenon gracile. The two investigated species produce strong extracellular copper complexing ligands: Oscillatoria redekei in the exponential and stationary growth phase, and Aphanizomenon gracile has a distinct detoxification capacity. The detoxification of copper by synthetic agents was investigated using ethylene-diamine-tetraacetic acid. Simultaneous addition of Cu2+ and Na2EDTA gives evidence for a slow complexation reaction. Hence an excess of Na2EDTA is necessary for a fast and complete detoxification of copper. Model calculations are reported to show that the precipitation of copper compounds is not probable under the conditions used.  相似文献   

11.
Response surface methodology (RSM) was employed to investigate the effects of different operational parameters on the biological decolorization of a dye solution containing malachite green (MG) in the presence of macroalgae Chara sp. The investigated variables were the initial pH, initial dye concentration, algae amount, and reaction time. Central composite design (CCD) was used for the optimization of biological decolorization process. Predicted values were found to be in good agreement with experimental values (R2 = 0.982 and Adj‐R2 = 0.966), which indicated suitability of the employed model and the success of RSM. The results of optimization predicted by the model showed that maximum decolorization efficiency was achieved at the optimum condition of the initial pH 6.8, initial dye concentration 9.7 mg/L, algae amount 3.9 g, and reaction time 75 min. UV–VIS spectra and FT‐IR analysis showed degradation of MG.  相似文献   

12.
In batch experiments with 0.5 nM benzo(a)pyrene in artificial sea water there are investigated the distribution and degradation of benzopyrene in the presence of various plants: Cladophora glomerata, Enteromorpha intestinalis, Fucus vesiculosus and Chara aspera (in each case 10 … 20 g/l dry weight). The conversion of benzopyrene in the presence of the plants is considerably promoted compared with the pure autoxidation, except in the presence of Fucus. Obviously, there prevails initially the accumulation of benzopyrene in the biomass. Whereas for Fucus even after 10 d still 89% of benzopyrene can be detected in the biomass, in the other species a degradation of benzopyrene in the biomass takes place, the respective oxidation products as diols, quinones and phenols being detected in the biomass in proportionately higher concentrations. With the exception of Fucus, the degradation of benzopyrene comes up to 40 … 60% within a period of 5 … 6d with the other species tested.  相似文献   

13.
The method is based on the determination of the number of the nonmotile sperms and/or the lethally damaged sperms with the aid of the fluorescent dye primuline. Incubation takes place at a suspension density of 10.000/mm3… 38.000/mm3, at 40°C or 46 °C for 15… 60 min. During the test with sublimate the loss of motility amounts to 55% at 4 mg/l Hg2+, the LC50 is 7.3 mg/l Hg2+. Phenyl-mercuric acetate causes the total loss of motility with 20 mg/l, the LC50 is above 168 mg/l (equivalent to 100 mg/l Hg2+). The LC50 of sodiumpentadecylmonosulphonate and dodecylpyridinchloride are 11.6 and 15.8 mg/l, resp. Filtrates of blooming of cyanophyceae on Baltic, having been digested by repeated freezing and thawing, with 1.5… 6.4 g/l dry matter showed motility losses of 30… 100 % for Nodularia spumigena, whereas no significant effect was produced by a filtrate of Microcystis aeruginosa with 28.2 g/l dry matter as well as water-blooming of Nodularia spumigena from the Small Jasmund Bodden.  相似文献   

14.
With colony numbers of 2 · 104… 3 · 105 and coliform contents of 2 · 103… 1 · 1 · 104 per ml, in the investigated river section 2.1% of colonies were resistant to tetracycline, 0.3% to chloramphenicol, 7.5% to kanamycin, 5.4% to trimethoprim, 12.7% to ampicillin and 0.14% to gentamycin. For the coliforms the resistances were 5.1% to tetracycline, 2.1% to chloramphenicol, 2.7% to kanamycin and 0.15% to gentamycin. There were isolated 63 different resistance types. Of the resistant Klebsiella strains 75% were resistant to three or more antibiotics. Of the coliform bacteria (Escherichia coli, Klebsiella, Enterobacter, Citrobacter) 31.6… 51.9% of the strains transferred their antibiotics-resistance to Escherichia coli K-12, for the antibiotics-resistant strains of Pseudomonas and Aeromonas a transfer of resistance was not observed at all.  相似文献   

15.
以9期Landsat TM/ETM+影像为数据源,基于K-T变换和归一化植被指数(NDVI),建立了湖泊蓝藻水华信息提取的决策树模型.基于大气顶面反射率图像,选用2005年10月17日太湖图像进行了对比验证,表明决策树模型比单波段阈值法、多波段阈值法(RVI、DVI、NDVI)能够更有效地提取蓝藻水华信息,区分陆生植被、水生植物和水华,省去了水体掩膜的过程.使用太湖2002年10月25日和2011年7月22日图像、巢湖2005年8月12日的图像,验证决策树模型方法和工作流程的有效性.使用多期TM图像确定了阈值的取值范围,其中,亮度、绿度、NDVI的下限值依次为0.191、-0.007、-0.054,湿度下限范围为0.07~0.15;亮度阈值上限范围为0.3~0.7、绿度为0.2~0.5、湿度为0.1~0.3,这些结果可作为湖泊蓝藻水华遥感监测的参考.  相似文献   

16.
The meliorated Oberes Rhinluch fen is used by agriculture as grassland with maize-cultivation on about 30 % of its area. In the ditch system of this area with water levels of 30 to 150 there were observed 67 taxa of aquatic plants and marsh plants, of which about 15 achieve covering degrees of more than 3 % and form 80 … 90 % of the biomass. Biomasses of between 20 … 184 g/m2 dry weight (Lemna) and 504 … 1612 g/m2 (Phragmites) are obtained in pure populations. In mixed populations the biomasses amount to between 304 and 916 g/m2 dry weight. According to their density and orientation, riparian copses and trees cause a more or less intense overshadowing of ditches, resulting in a considerable reduction of the biomass of macrophytes. By copses and trees on the south side of the waters the light available may be reduced to 30 %, from which a reduction of the biomass to 10 … 30 % results. By means of such planting it is possible to control the growth of plants in order to reduce the necessary and very expensive weed-removal and bottom-clearing actions.  相似文献   

17.
By the example of some phenols and qninones, in aqueous solutions possibilities for the quantitative determination are tested separately and in the mixture. Methods for thin-layer chromatography and spectrophotometry were developed. There can be chromatographically deteeted between 5 and 80 μg of substance. Phenol and quinone concentrations of 1.5 · 10?3 … 0.5 · 10?4 M were spectrophotometrically investigated.  相似文献   

18.
To determine some of the environmental effects that influence the relative proportions of pigments in algae, high pressure liquid chromatographic (HPLC) analysis was employed to determine the relative amounts of common photosynthetic pigments in batch cultures of the diatoms,Fragilaria crotonensis andThalassiosira pseudonana, and the green algae,Scenedesmus abundans, andHaematococcus pluvialis, illuminated for 12 hours each day. Similar analyses were conducted in five-day experiments during which cultures ofF. crotonensis andS. quadricauda were kept in continuous darkness. Comparing the results to those for controls continuing to receive the daily illumination indicated that the diatoms and green algae react similarly to light deficiency. The relative amounts of the main accessory pigment in the diatoms, fucoxanthin, and that in the green alga, apparently lutein, decreased as a reaction to a lack of illumination, while the total chlorophyll level in algae of both groups remained nearly constant. Quantitative differences induced by the experimental conditions were considerably less that those observed among different species of diatom or among the different green algae, however. Finally, cultures ofS. quadricauda were analyzed and then kept for 43 days without the addition of any nutrients. A proportion of the culture was kept for this period in perpetual darkness while another continued to receive 12 hours of illumination. The results show that considerable changes occur as the cultures age, and that these changes occur more slowly in the darkness. Some consequences of these findings for phytoplankton production studies based on analyses of photosynthetic pigments are discussed.  相似文献   

19.
Blue-green algae have been observed to affect limestone weathering on Aldabra Atoll, Indian Ocean. Three different habitats can be identified on the rock surface, i.e. epilithic, chasmolithic, and endolithic. Algae in each habitat may affect weathering in various ways. Samples of blue-green algae and rock were taken from various terrestrial and coastal environments on Aldabra Atoll. Samples of limestone tablets and calcite crystals after one year in situ were also studied. Light and S.E.M. microscopy revealed that endolithic boreholes were present on many samples, especially those from frequently wetted sites, to a maximum depth of 800 μm. An ‘altered zone’ of micrite and algal filaments was also discovered in many samples. From morphological and petrographical evidence blue-green algal influences on weathering on Aldabra Atoll seem to be very complex and cannot easily be related to small scale landforms.  相似文献   

20.
After the checking for the toxic inhibition of degradation, the testing of the degradation behaviour at concentrations below the toxicological threshold value should be performed. For this, activated sludge with 1.5 … 2 g/l organic dry weight in special reaction vessels with a stirring and aeration equipment as well as electrochemical oxygen measurement is used. The possibly necessary adaptation is effected by a repeated change of the aqueous phase with the test substance as the single carbon source. Measurements are carried out in three vessels: control, experimental vessel and another experimental vessel for the makeup of volume at sampling. The increase of biomass and the consumption of substrate are determined from samples. Determinations of totals as COD and/or Corganic are recommended, since the determination of the pure substrate allows only statements on the persistence, but not on the full degradation. The technique, represented with the schematic diagram and examples of application, can be automated easily.  相似文献   

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