铬离子对藻类生长的影响

利用自然光照条件,在不同铬离子质量浓度下,对5种藻类的生长进行了实验研究.研究结果表明:5种藻类在不同的光波长下,其吸收光谱存在两个最强的吸收区: 420～440 nm的蓝紫光部分和660 nm 的红光部分;在不同铬离子质量浓度0～20.63 mg·L-1范围内,5种藻类生长受到不同程度的抑制,其耐受性也尽不相同,经过分析和比较后得出5种藻类对铬的耐受性大小顺序为:微囊藻(Microcystis)＞水华鱼腥藻(Anabaena flos-aquae)＞细长聚球藻(Synechococcus elongatus)＞斜生栅藻(Scenedesmus obliquus)＞蛋白核小球藻(Chlorella pyrenoidose).     

Interactions between two species of marine diatoms: Effects on their individual copper tolerance

The purpose of this study was to examine the effect of the interaction of two species of marine diatoms,Skeletonema costatum (Cleve) Greville andNitzschia thermalis (Ehrenberg) Auerswald, on their individual copper tolerances. The two species, obtained from stock cultures in 1989, were grown together at three copper concentrations (1, 4 and 5 × 10^–7 M added total copper). In the unialgal cultures that were used as controls, the two species grew as predicted from their tolerance tests. However, in mixed cultures,N. thermalis was the only species that exhibited growth, regardless of the copper concentration in the medium. Growth retardation ofS. costatum in the presence ofN. thermalis was attributed to an inhibitory exudate. The effect of the exudate appeared to have been temporary, as demonstrated by the extended lag phase and subsequent satisfactory exponential growth rate ofS. costatum. It is suggested that the exudate degraded within a period of 5 d (=lag phase) because exponential growth rate was resumed. It thus appears that the interaction between the two diatom species is more important in determining the survival ofS. costatum than its individual copper tolerance. This is not the case forN. thermalis. Such interactions would be unaccounted for in single-species toxicity tests. On the other hand, if they are known, prediction of how a community that includes these two species would respond to copper additions becomes possible.     

BDE-47对4种海洋微藻抗氧化酶活性的影响

运用实验生态学和生物化学的方法,研究了不同质量浓度的2,2',4,4'-四溴联苯醚(BDE-47)对海水小球藻Chlorellaautotropica,牟氏角毛藻Chaetoceros muelleri,中肋骨条藻Skeletonema costatum和赤潮异弯藻Heterosigam akashiwo的抗氧化酶活性的影响.结果表明:在实验设定质量浓度范围内(0.1～2.5 μg·L~(-1)),4种微藻的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)均能出现一定的应激活性,以减少BDE-47胁迫对藻细胞自身的危害,但是酶活增加的幅度却有很大不同.与赤潮异弯藻和中肋骨条藻相比,海水小球藻和牟氏角毛藻的SOD和CAT对BDE-47具有较高的敏感性.4种海洋微藻的SOD和CAT对BDE-47的敏感性顺序依次为:海水小球藻>牟氏角毛藻>中肋骨条藻>赤潮异弯藻.因此,海水小球藻的SOD和CAT可以作为指示海洋环境中BDE-47污染水平的生物标志物.     

东海原甲藻的光周期效应研究

以东海原甲藻ProrocentrumdonghaienseLu为试验材料,设置了短光周期(A)和长光周期(B)两组试验:A组分光周期1、2、4、6、8、10和12h7个处理,B组分光周期12、14、16、18、20、22和23h7个处理,测定了东海原甲藻的细胞密度、叶绿素a含量、蛋白质含量、生物量和可溶性糖等指标。结果表明,在13个不同的光周期处理中,随着光周期的不断延长,东海原甲藻的细胞密度等一系列指标值均不断上升,各指标和光周期的长度呈现正相关的关系。结果表明东海原甲藻是一种喜长光照的赤潮藻类。     

Effects of copper and zinc on two planktonic ciliates

The interactive effects of copper and zinc on two estuarine planktonic ciliates, Favella sp. and Balanion sp., were determined in seawater media in which the free metal ion activities were controlled by nitrilotriacetic acid (NTA) trace metal ion buffer systems. Cupric ion activities of 10^-10 M caused abnormal motility in both ciliates in shortterm (5 h) tests, and cupric ion activities as low as 10^-12.8 M decreased the growth rates of both species in longer-term experiments. In the short-term tests, zinc ion activity by itself did not affect the motility of the ciliates, but there were significant interactions between copper and zinc. In the longer-term experiments, the growth of Favella sp. was optimal at the lowest cupric ion activity (10^-13 M) and the two lowest zinc ion activities (10^-12 and 10^-13 M) and the two lowest zinc ion activities (10^-12 and 10^-11 M), and copper and zinc inhibited growth at activities above these values. By contrast, optimal growth rate of Balanion sp. occurred at the highest zinc ion activity (10^-10 M) and the lowest cupric ion activities (10^-13 to 10^-12 M) and growth rate was reduced at zinc ion activities 10^-11 M. There was an antagonism between copper and zinc which was particularly pronounced in Balanion sp.Contribution No. 5871 from the Woods Hole Oceanographic Institution     

铜胁迫对两种地衣植物生理生化特征的影响

以中国树花（Ramalina sinensis Jatta.）和亚花松萝（Usnea subfloridana Stint.）为材料,研究了铜胁迫对这两种地衣植物生理生化特性的影响。结果表明：在Cu2＋的作用下,中国树花和亚花松萝体内叶绿素质量分数和过氧化物酶（POD）活性发生一系列的变化,且表现出明显的剂量效应关系和时间效应关系。随着处理浓度的加大和处理时间的延长,中国树花体内叶绿素质量分数呈现先降后升再降。在处理的48 h,当Cu2＋质量浓度为0.1 mg.mL-1时中国树花体内叶绿素a质量分数下降为0 mg.mL-1时的16.34%,叶绿素总质量分数下降为42.54%,而当Cu2＋质量浓度为0.5 mg.mL-1时叶绿素a质量分数下降为22.95%,叶绿素总质量分数下降为60.39%,亚花松萝体内叶绿素质量分数呈现先升后降的趋势,当Cu2＋质量浓度为0.1 mg.mL-1时,处理48 h后的亚花松萝体内叶绿素质量分数比36 h下降18.82%;当Cu2＋质量浓度为0.5 mg.mL-1时,处理48 h后的亚花松萝体内叶绿素质量分数比36 h下降23.52%。随着处理浓度的加大和处理时间的延长,中国树花过氧化物酶活性呈现上升的趋势,当Cu2＋质量浓度为0.1 mg.mL-1时,处理24、36、48 h后过氧化物酶的活性分别增加为88.1%、64.83%和65.49%;当Cu2＋质量浓度为0.5 mg.mL-1时,分别增加为69.83%、82.05%和82.57%。而亚花松萝过氧化物酶活性呈现先下降后上升等波动性变化,Cu2＋质量浓度为0.1 mg.mL-1时,处理24、36、48 h后过氧化物酶的活性先下降62.56%,后增加7.93%,又下降42.28%;当Cu2＋质量浓度为0.5 mg.mL-1时,比对照组分别下降72.92%、33.49%和62.56%。对比两种地衣植物发现,中国树花体内生理指标的变化较亚花松萝的明显,说明中国树花对铜胁迫反应较敏感,有利于监测重金属铜污染。     

Effects of copper and cadmium on growth,swimming and predator avoidance in Eurytemora affinis (Copepoda)

In this study we demonstrate the sensitivity of swimming behavior and predator-escape responses of nauplii of the estuarine copepod Eurytemora affinis to sublethal doses of Cu and Cd. Behavior was generally altered at metal doses below those affecting growth rates or survival of the copepods. Swimming velocities of Cu-dosed nauplii were different from controls at all concentrations of Cu tested (10–50 g l^-1 total Cu) after 24- to 48-h exposure, whereas development rate of nauplii was significantly reduced only after 96 h at 25 g l^-1. The 96 h LC50 for Cu was approximately 30 g l^-1 Cu. Naupliar swimming velocity was also affected by Cd. Swimming speeds were reduced after 24 h at 130 g l^-1, and development was slowed after 48 h at 116 g Cd l^-1. The 96-h LC50 was >120 g l^-1. Little is known of the adaptive role of specific motile behaviors in the success of larval copepods. We investigated the relationship of swimming speed to predator — prey interactions of the nauplii using both real and simulated predators. Nauplii exposed to Cu for 24 h were observed to be generally hyperactive, a condition which could increase their encounter frequency with predators. Reduced numbers of escape responses of nauplii to a simulated predator, another indication of increased vulnerability to predation, were observed only after 48-h exposure to Cu. Nevertheless, feeding rates of non-dosed larval striped bass on dosed nauplii (24 h at 25 g Cu l^-1) were significantly higher than on control nauplii. Feeding rates of larval mysid shrimp, however, were not higher on similarly dosed nauplii; 24 h exposure of nauplii to >30 g Cu l^-1 did result in increased predation by mysids.Contribution No. 272 of the US EPA Environmental Research Laboratory, Narragansett, Rhode Island 02882, USA     

Shell growth response of mussels (Mytilus edulis) exposed to toxic microalgae

Mussels (Mytilus edulis) were exposed to the algaeAlexandrium ostenfeldii, Chrysochromulina polylepis, Gyrodinium aureolum, Gymnodinium galatheanum andHeterosigma akashiwo for 24 h; significant reductions in growth rate, as compared to the control, were observed after exposure toA. ostenfeldii, C. polylepis, G. aureolum andG. galatheanum at initial concentrations of 4.5 × 10⁶, 110 × 10⁶, 9 × 10⁶ and 120 × 10⁶ cells l^–1, respectively. Exposure to high initial concentrations of the non-toxic algaeTetraselmis suecica (174 × 10⁶ cells l^–1) andIsochrysis galbana (610 × 10⁶ cells l^–1) showed no adverse effect on growth rate. When mussels with reduced growth were transferred to clean seawater, they recovered to > 90% of control growth within 2 to 4 d. Exposure to algal filtrates of the toxic algal cultures produced no reduction in growth rate.     

蒽对二种海洋微藻抗氧化系统的影响

研究了多环芳烃（PAHs)－蒽对2种海洋微藻抗氧化系统的影响。结果表明,随着蒽浓度的增加,小新月菱形藻和亚心形扁藻的非酶性系统中的类胡萝卜素（CAR）和还原型谷胱甘肽（GSH）含量下降,酶性系统中的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性下降,当加入抗氧化剂GSH时,蒽对两种海洋微藻的伤害作得以缓解,说明,蒽使海洋微藻的抗氧化系统破坏,损及体内活性氧化作用,对微藻的膜系统产生伤害。图6参12     

Effects of cerium oxide nanoparticles on biochemical and oxidative parameters in marigold leaves

Abstract

The effects of suspensions of cerium oxide nanoparticles sprayed onto marigold seedlings (Calendula officinalis L.) at concentrations between 50 and 3200 mg L^?1 were studied. At concentrations of 50 and 100 mg L^?1, the nanoparticles had a slight positive effect on some growth parameters, but at higher concentrations they caused severe oxidative damage. Activities of phenylalanine ammonia lyase and lipoxygenase increased from 400 mg L^?1 upward, tyrosine ammonia lyase from 1600 mg L^?1. Ascorbate and glutathione contents decreased from 400 mg L^?1 upwards.     

Comparison of growth and lipid accumulation properties of two oleaginous microalgae under different nutrient conditions

This study compared the growth and lipid accumulation properties of two oleaginous microalgae, namely, Scenedesmus sp. LX1 and Chlorella sp. HQ, under different nutrient conditions. Both algal species obtained the highest biomass, lipid content and lipid yield under low-nutrient conditions （mBGll medium）. The biomass, lipid content and lipid yield of Scenedesmus sp. LX1 were 0.42g·L^-1, 22.5% and 93.8mg·L^-1, respectively. These values were relatively higher than those of Chlorella sp. HQ （0.30g·L^-1, 17.1% and 51.3mg·L^-1, respectively）. These algae were then cultivated in an SE medium that contained more nutrients; as a result, the biomass and lipid yield of Scenedesmus sp. LX1 reduced more significantly than those of Chlorella sp. HQ. Opposite results were observed in lipid and triacylglycerols （TAGs） contents. The cell sizes of both algal species under low-nutrient conditions were larger than those under high-nutrient conditions. Chlorella sp. HQ cells did not aggregate, but Scenedesmus sp. LX1 cells flocculated easily, particularly under low-nutrient conditions. In summary, low-nutrient conditions favour the growth and lipid production of both algae, but Scenedesmus sp. LX1 outperforms Chlorella sp. HQ.     

Effects of monospecific algal diets of varying biochemical composition on the growth and survival of Pacific oyster (Crassostrea gigas) larvae

Using monospecific diets of Thalassiosira pseudonana cells grown under different steady-state conditions, it was determined that higher growth rates of larval Crassostrea gigas Thunberg were obtained when fed T. pseudonana cells grown under high light. High light grown T. pseudonana cells consistently contained relatively more of the saturated fatty acids 14:0 and 16:0. Considered over three independent experiments, high light grown T. pseudonana cells were lower in protein and higher in carbohydrate than low light grown cells. Higher growth rates of larval C. gigas were obtained on diets with more of the essential fatty acid (EFA) 22:63, and less of the other EFA, 20:53. The relative requirements of C. gigas larvae for the essential fatty acids 20:53 and 22:63 are discussed. Faster growing larvae contained higher percentages of the fatty acids 14:0 and 16:0, and lower percentages of 22:2j. Oyster growth rates were correlated with their content of the fatty acids: 14:0, 16:0 and 22:2j in two experiments utilizing separately spawned batches of larvae. Fatty acid profiles are proposed as a technique for assessing larval condition. C. gigas larvae contained ten times the percent composition of the FAs 16:43, 18:17, 20:17 and 22:2j compared with their diet. Correlation analysis suggests that the dietary source of 18:17, 20:17 and 22:2j was 16:17. It is concluded that T. pseudonana cells grown under high light are a superior diet for C. gigas larvae in comparison with low light grown cells of the same species.     

Effects of UV-B irradiation on growth and survival of Antarctic marine diatoms

Growth rate, survival, and stimulation of the production of UV-B (280 to 320 nm) absorbing compounds were investigated in cultures of five commonly occurring Antarctic marine diatoms exposed to a range of UV-B irradiances. Experimental UV-B exposures ranged from 20 to 650% of the measured peak surface irradiance at an Antarctic coastal site (0.533 J m^-2 s^-1). The five diatom species (Nitzschia lecointei, Proboscia alata, P. inermis, Thalassiosira tumida and Stellarima microtrias) appear capable of surviving two to four times this irradiance. In contrast to Phaeocystis cf. pouchetii, another major component of the Antarctic phytoplankton, the concentrations of pigments with discrete UV absorption peaks in diatoms were low and did not change significantly under increasing UV-B irradiance. Absorbance of UV-B by cells from which pigments had been extracted commonly greatly exceeded that of the pigments themselves. Most of this absorbance was due to oxidisable cell contents, with the frustule providing the remainder. Survival of diatoms did not correlate with absorption by either pigments, frustules or oxidisable cell contents, indicating that their survival under elevated UV-B irradiances results from processes other than screening mechanisms.     

Inhibitory effects of copper on marine dinoflagellates

The effect of copper on three species of marine dinoflagellates [Scrippsiella faeroense (Paulsen) Balech et Soares, Prorocentrum micans Ehrenberg, Gymnodinium splendens Lebour] was studied. It inhibited the growth of all species and was lethal to one species in batch cultures. The effect was more pronounced in semicontinuous culture than in batch cultures. Chlorophyll concentrations and rate of uptake of radioactive carbon by cells of S. faeroense were affected in a manner similar to cell numbers. Copper inhibited growth of cells, most probably either by arresting cell division or by penetrating inside the cell and affecting metabolism.     

Effects of copper on the faunas of marine soft-sediments: An experimental field study

Although laboratory experimental studies have shown that copper is toxic to marine organisms at concentrations found in contaminated sediments, there is little unequivocal evidence of undesirable ecological effects in the field, other than at extreme concentrations. We describe a study in Botany Bay, New South Wales, Australia, in which the concentrations of copper in marine sediments were experimentally enhanced. Changes in the abundance and taxonomic composition of the fauna of copper-treated sediments relative to those of two control treatments were monitored over a period of six months. Univariate (ANOVA) and multivariate (non-metric multidimensional scaling, MDS) analyses of the changes in the fauna showed that increased concentrations of copper (140 to 1200 g g^-1 compared with background concentrations of 29 to 40 g g^-1) had an impact on the fauna. The nature of the response varied among taxa. For example, in some taxa, numbers of individuals decreased through time relative to controls, whereas the abundance of another taxon remained fairly constant through time in the copper treatment while numbers of control individuals increased. Differences in the changes of the faunas through time among the control and copper treatments were not always consistent among replicate experimental units 5 m apart, nor were they consistent between replicate experimental sites 100 m apart. The magnitudes of the changes in the faunas caused by the copper treatment are considered in the context of the magnitude of previously measured natural temporal variation.     

The effects of a no. 2 fuel oil and two crude oils on the growth and photosynthesis of microalgae

Seawater, when equilibrated with a sample of No. 2 fuel oil, becomes toxic in varying degrees to growth of representative types of microalgae, two blue-greens, a diatom, two greens, and a dinoflagellate. For a sensitive organism such as Thalassiosira pseudonana, Strain 3H, 5 ml of seawater equilibrated with fuel oil (containing 15 mg/l of organics) in 20 ml of growth medium is lethal, or roughly in the range of 40 to 400 ppb if the toxic material(s) constitute 1 to 10% water also immediately stops photosynthesis in organism 3H. For other microalgae tested e.g. 580 (a green alga) and PR-6 (a blue-green alga), similar effects on growth and photosynthesis were found, but required higher concentrations of the oil-equilibrated seawater. Water solubles from Kuwait or Southern Louisiana crude oils (when the straight crude oil was equilibrated 1:8 with seawater) were not toxic; however, specific fractions obtained by distillation did show some water-soluble toxicity. Growth experimetns in open or closed growth systems revealed that most organisms were inhibited by varying amounts of these two crude oils when in direct contact with them. Organism 580 would not grow above 5 μl of Southern Louisiana/25 ml of medium, or 10 μl of Kuwait/25 ml of medium (oil in direct contact with algae). With both the seawater equilibrated with fuel oil and the crude oils, the toxic activity is mainly localized in medium and higher boiling fractions derived from distillation cuts from these materials.     

改良剂对铜矿尾矿砂与菜园土混合土壤性质及黑麦草生长的影响

用蒙脱石、稻草、鸡粪作为改良剂 ,研究不同改良剂对铜矿尾矿砂与菜园土混合土壤pH、有效态重金属含量、脲酶和磷酸酶活性以及混合土壤上种植的黑麦草生长的影响。结果表明 :添加蒙脱石对不同生长期黑麦草的生长量没有显著影响 ;使用稻草和鸡粪处理尽管在开始阶段不利于黑麦草 (第 1茬和第 2茬 )的生长 ,但随时间延长 ,黑麦草的生物量 (第 3茬和第 4茬 )明显增加 ,表现出很好的后效。黑麦草的根重与鸡粪的添加量关系显著 ,施用稻草的纯尾矿砂处理组 (处理 2 2 )根重最大 ,而且蚯蚓只能在使用适量稻草的处理条件下才能在混合土壤中生长。土壤酶的分析发现 ,磷酸酶的活性除了在蚯蚓能够生长的处理组表现出较高外 ,其它处理之间无明显差异 ,但脲酶的活性则随着稻草和鸡粪施用量的增加而显著提高。各处理之间土壤的 pH值变化不大。添加稻草减少了土壤中有效态重金属的含量 ,而使用鸡粪处理明显增加了土壤中包括铜、铅和锌等有效态重金属的含量 ,说明在施用含有重金属的畜禽粪便时务必小心谨慎 ,以防二次污染。     

Effects of the insect growth regulator Dimilin® (TH 6040) on larval development of two estuarine crabs

Effects of Dimilin^® (TH 6040), an insect growth regulator which interferes with the formation of the insect cuticle, were studied on the larval development of Rhithropanopeus harrisii (Gould) and Sesarma reticulatum (Say) (Crustacea: Brachyura). When larvae were exposed to 0.5 (R. harrisii only), 1, 3, 5, 7, and 10 ppb Dimilin from hatching to the first crab stage, survival in both species decreased in relation to increased concentrations of Dimilin. Survival of R. harrisii larvae wa significantly lower at 1 ppb and higher levels compared with control experiments, and in S. reticulatum a significant decrease in survival began at the 3 ppb level. At 10 ppb Dimilin, no larvae survived to the megalopa stage in either of the two species. The results indicate that early stage larvae of R. harrisii are more sensitive to Dimilin than those of S. reticulatum. When R. harrisii larvae were treated with 10 ppb Dimilin during the intermolt period of each of the 4 zoeal stages, nearly all larvae died during molting to the succeeding stage. First zoeal larvae of R. harrisii exposed to 10 ppb Dimilin at various days during the intermolt period were more sensitive to the compound late than early in the period. It is suggested that Dimilin also may interfere with the formation of the cuticle in crab larvae.