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1.
The capability ofScenedesmus obliquus to remove cations (K^+, Na^+, Ca^2+, Mg^2+) from saline- alkaline water was investigated at different salinities (0, 5, 10, 15, 20, 25) and carbonate alkalinities (0, 5, 10, 15, 20, 25, 30, 35 mmol/L). K^+, Na^+, Ca^2+, and Mg^2+ in saline-alkaline water were efficiently removed by S. obliquus. The maximum removal of the cations (29.37 mg for K^+, 185.85 mg for Na^+, 23.07 mg for Ca^2+, 66.14 mg for Mg^2+) occurred at salinity 25. The maximum removal of K^+ (2.28 mg), Na+ (6.62 mg), Ca^2+ (1.01 mg), and Mg2+ (0.62 mg) occurred at carbonate alkalinities of 25 mmol/L for K*, 35 mmol/L for Na+, 20 mmol/L for Ca2+, and 25 mmol/L for Mf+, respectively. Under a salinity stress, the concentration of Na' in S. obliquus increased significantly, while that of K~ decreased significantly. The concentrations of Ca^2+ and Mg2+ decreased as well. The ratios of K+/Na~, Ca2+/Na^+, and Mg^2+/Na^+ were significantly lower in all salinity treatments than those of the control. Under alkaline stress, the concentrations of Nan and K+ in S. obliquus decreased significantly and the ratios of K^+/Na^+, Ca2+/Na^+, and Mg^2+/Na^+ were significantly higher in all treatments than in the control. Moreover, the concentrations of Ca2+ and Mg2+ in S. obliquus at alkalinities of 5-10 mmol/L were significantly higher than those of the other treatments. The removal of Na+ by S. obliquus mainly occurs through biosorption, and Mg^2+ and Ca^2 + were removed through both biosorption and bioaccumulation.  相似文献   

2.
3.
The effects of salinity on hemolymph osmotic pressure, Na^+ concentration and Na^+-K^+-ATPase activity of gill of Chinese crab Eriocheir sinensis were studied. The results showed that hemolymph osmotic pressure and Na^+ concentration increased significantly (P〈0.05), and the Na^+-K^+-ATPase activity of gills decreased significantly (P〈0.05) when salinity increased from 0 to 16. The hemolymph osmotic pressure and Na^+ concentration in each treatment group rose remarkably at 0.125 d or 0.25 d, while the Na^+-K^+-ATPase activity of gill reduced gradually with increased experiment time in 3 d. Then the three parameters remained at a constant level after 0.25 d, 0.125 d and 3 d, respectively, and higher hemolymph osmotic pressure, higher Na^+ concentration and lower Na^+-K^+-ATPase activity of gill occurred at higher salinity. The effect of salinity change on protein concentration of hemolymph was indistinct (P〉0.05); However, the protein concentration decreased gradually with the increase of salinity from 0.25 d to 1d, and then tended to be stable from day 1 to day 15.  相似文献   

4.
The adsorption and desorption of algae Cladophora fascicularis and their relation with initial Cd^2+ concentration, initial pH, and co-existing ions were studied. Adsorption equilibrium and biosorption kinetics were established from batch experiments. The adsorption equilibrium was adequately described by the Langmuir isotherm, and biosorption kinetics was in pseudo-second order model. The experiment on co-existing ions showed that the biosorption capacity of biomass decreased with an increasing concentration of competing ions. Desorption experiments indicated that EDTA was efficient desorbent for recovery from Cd^2+. With high capacities of metal biosorption and desorption, the biomass of Cladophora fascicularis is promising as a cost-effective biosorbent for the removal of Cd^2+ from wastewater.  相似文献   

5.
During the 15th Conference of the Parties(COP 15),Parties agreed that reducing emissions from deforestation and forest degradation and enhancing ’removals of greenhouse gas emission by forests’(REDD+) in developing countries through positive incentives under the United Nations Framework Convention on Climate Change(UNFCCC) was capable of dealing with global emissions.As REDD+ seeks to lower emissions by stopping deforestation and forest degradation with an international payment tier according to baseline scenarios,opportunities for ecosystem benefits such as slowing habitat fragmentation,conservation of forest biodiversity,soil conservation may be also part of this effort.The primary objective of this study is to evaluate ecosystem-based benefits of REDD+,and to identify the relationships with carbon stock changes.To achieve this goal,high resolution satellite images are combined with Normalized Difference Vegetation Index(NDVI) to identify historical deforestation in study area of Central Kalimantan,Indonesia.The carbon emissions for the period of 2000-2005 and 2005-2009 are 2.73 × 10 5 t CO 2 and 1.47 × 10 6 t CO 2 respectively,showing an increasing trend in recent years.Dring 2005-2009,number of patches(NP),patch density(PD),mean shape index distribution(SHAPE_MN) increased 30.8%,30.7% and 7.6%.Meanwhile,largest patch index(LPI),mean area(AREA_MN),area-weighted mean of shape index distribution(SHAPE_AM),neighbor distance(ENN_MN) and interspersion and juxtaposition index(IJI) decreased by 55.3%,29.7%,15.8%,53.4% and 21.5% respectively.The area regarding as positive correlation between carbon emissions and soil erosion was approximately 8.9 × 10 3 ha corresponding to 96.0% of the changing forest.These results support the view that there are strong synergies among carbon loss,forest fragmentation and soil erosion in tropical forests.Such mechanism of REDD+ is likely to present opportunities for multiple benefits that fall outside the scope of carbon stocks.  相似文献   

6.
The effects of various salinity fluctuation amplitudes (2, 4, 6 and 8) on the growth, osmolarity, Na+-K+-ATPase activity and Hsp70 of juvenile Fenneropenaeus chinensis cultured in seawater with a salinity of 20 were studied. The results show that weight gain in the salinity fluctuation treatments was better than that in control; in particular, the weight gain of treatments S4 and S0, at 231.8% and 196.3%, respectively, was significantly different (P<0.05). The hemolymph osmolarity of treatments S0, S2, S4, S6 and S8 was 635.4, 630.8, 623.6, 614.4 and 600.3 mOsm/kg, respectively, and decreased with increasing salinity fluctuation amplitude. The level of Na+-K+-ATPase activity in gills of F. chinensis was higher than that in hepatopancreas, but there were no significant differences among all treatments, either in gills or hepatopancreas (P>0.05). The relative level of Hsp70 in treatment S4 was 48.4% and 40.4% higher than control in muscle and eyestalks, respectively, with the highest values being recorded under a salinity fluctuation amplitude of 4.  相似文献   

7.
Hydrolysis activities of PACC (particle of agarose-Ce^4+ complex, newly made through double emulsification) for compounds containing phosphodiester or peptide bonds were studied. The results showed that PACC could hydrolyze organophosphorous pesticides not only in water but also in vegetable juice or tea extract. Hydrolysis rates of methamidophos, omethoateand chlorpyrifos in water are 32.39%, 27.12% and 46.62% respectively, those of chlorpyrifos and methamidophos in mung sprout juice 38.28% and 35.45% respectively, and that of chlorpyrifos in tea extract 59.76%. Hydrolysis rates of BSA (bovine serum albumin) in water and protein in tea extract by PACC increase by 54.30% and 86.46% respectively as compared with the control.  相似文献   

8.
K.  K.  I.  U.  Arunakumarat  张学成 《中国海洋湖沼学报》2009,27(2):383-388
The unicellular cyanobacterium Synechocystis sp. PCC 6803, a model organism known for its unique combination of highly desirable molecular genetic, physiological and morphological characteristics, was employed in the present study. The species was cultured in BG11 liquid medium contained various initial concentrations of Pb2+ and Cd2+ (0, 0.5, 1, 2, 4, 6 and 8 mg/L). The experiment was conducted for six days and the metal induced alterations in the ultrastructure, growth and pigment contents were assessed. Alterations in the ultrastructure of the Synechocystis sp. PCC 6803 cells became evident with the increased (>4 mg/L Pb2+) metal concentration. The photosynthetic apparatus (thylakoid membranes) were found to be the worst affected. Deteriorated or completely destroyed thylakoid membranes have made large empty spaces in the cell interior. In addition, at the highest concentration (8 mg/L Pb2+), the polyphosphate granules became more prominent both in size and number. Despite the initial slight stimulations (0.2, 3.8 and 6.5% respectively at 0.5, 1 and 2 mg/L Pb2+), both metals inhibited the growth in a dose-dependent manner as incubation progressed. Pigment contents (chlorophyll α, β carotene and phycocyanin) were also decreased with increasing metal concentration. Cells exposed to 6 mg/L Pb2+, resulted in 36.56, 37.39 and 29.34% reductions of chlorophyll α, β carotene and phycocyanin respectively over the control. Corresponding reductions for the same Cd2+concentrations were 57.83, 48.94 and 56.90%. Lethal concentration (96 h LC50) values (3.47 mg/L Cd2+ and 12.11 mg/L Pb2+) indicated that Synechocystis sp. PCC 6803 is more vulnerable to Cd2+ than Pb2+. Supported by the Chinese Scholarship Council  相似文献   

9.
《地理信息世界》2003,1(3):C004-C004
为完善人类自主办公环境,惠普推出一款全新的多功能大幅面高效打印机,它可以完成全色彩、大幅面的扫描、复印、打印功能,满足CAD、GIS等专业领域的多应用需求。因此,我们可称它为业界首款多功能大幅面一体机。  相似文献   

10.
Fe^2+ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe^2+ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentrations of Fe^2+. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1-102.1μg/L, 10-100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentrations, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually.  相似文献   

11.
The effects of environmental Na+/K+ ratio on the gill ion-transport enzyme activity, plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that, plasma osmolality was similar among flounder adapted to different Na+/K+ ratios of saline groundwaters (P>0.05), while the growth, gill Na+, K+-ATPase and HCO3 -ATPase activities were affected by Na+/K+ ratio significantly (P<0.05). The gill Na+, K+-ATPase activity reached its maximum on day 3, then decreased gradually from day 3 to day 9 and remained constant from day 9 to day 15. The peak values of gill Na+, K+-ATPase activity were detected on day 3 for all Na+/K+ ratios of saline groundwaters, then the enzyme activities descended, and on day 9 the enzyme activities achieved steady state, and the gill HCO3 -ATPase activity increased rapidly and achieved steady state after one day. During steady state, the gill Na+, K+-ATPase and HCO3 -ATPase activity of Na+/K+ ratios 20 and 40 treatments were significantly higher than those in the control group (Na+/K+ ratio 27.5), while there were no significant differences between the Na+/K+ ratio 30 treatment and the control group; the gill Na+, K+-ATPase activity of Na+/K+ ratio 20 and 40 treatments were significantly higher than that for ratio 30 treatment, but there were no significant differences of gill HCO3 -ATPase activity among these treatments. At the end of the 15-day experiment, the weight gain (%) and specific growth rate (SGR) of flounders maintained in seawater were significantly higher than those in groundwaters; significant differences also occurred among the treatments; Na+/K+ ratio 30 treatment had the highest values (33.7% and 1.94 respectively), which were significantly higher than those under Na+/K+ ratios 20 and 40 treatments. Therefore, for the saline groundwater used in this experiment, it is suggested that the Na+/K+ ratio be adjusted to approximately 30, i.e., as close to that of natural seawater as possible in the culture of flounder.  相似文献   

12.
研究了盐度23下青蛤(Cyclina sinensis)鳃、斧足、外套膜和内脏团中Na+/K+-ATPase的活性差异,并以活性高的鳃组织为对象,对青蛤实施了低盐(23→16)和高盐(23→36)突变的胁迫,监测了鳃组织中Na+/K+-ATPase活性的动态变化。结果表明,盐度23下青蛤鳃组织中Na+/K+-ATPase的活性显著高于其他组织;在盐度突降胁迫下,鳃组织中Na+/K+-ATPase的活性于前16 d逐渐升高,第17d起显著升高(p<0.05),第18 d达到峰值,于第20 d回落,但仍高于起始水平;在盐度骤升胁迫下,鳃组织中Na+/K+-ATPase的活性于前13d逐渐降低,第14 d起显著降低(p<0.05),于第15 d达到最低值,继而回升至平稳水平,但仍低于起始水平。青蛤不同盐度胁迫下其鳃组织中Na+/K+-ATPase活性的响应方式不同,低盐时活性增加,而高盐时活性下降;此外,青蛤在盐度胁迫下对自身渗透压的调节则需较长时间。  相似文献   

13.
Mud crab (Scylla serrata) is an important commercial crustacean in China. An experiment was designed to study the effect of cold stress on S. serrata. After a one-week adaptation at 28oC, the temperature is suddenly reduced to 4oC. The crabs were sampled every 2 h for 10 h and dissected immediately to measure the enzyme activity. The crabs at room temperature (28oC) were used as the control group. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), the content of malondialdehyde (MDA) and the activity of 4 ATPases (Na , K -ATPase; Mg2 -ATPase; Ca2 -ATPase; Ca2 , Mg2 -ATPase) were measured biochemically. In contrast to the control group, the SOD activity increased significantly from 2 to 6 h after the cold stress, and then decreased. The CAT and GPX activities increased in 2 h, and then decreased gradually. The content of MDA increased gradually in 4 h. The activity of Na , K -ATPase decreased in 2 h, increased up to the top value at Hour 6, then decreased again. The activities of Mg2 -ATPase, Ca2 -ATPase and Ca2 , Mg2 -ATPase increased significantly in 6 h, insignificantly in any other hours. Under cold stress, the activity of antioxidative enzymes in S. serrata was reduced at first then stabilized, ROS-scavenging weakened, and MDA accumulated gradually in the gill after 6 h. The activity of the 4 ATPases in the crab decreased after 6 h, suggesting that the ability to regulate ion concentration has been paralyzed. Therefore, the maximum period to sustain healthy meat in the crab under cold stress is 6 hours.  相似文献   

14.
We evaluated the ability of juvenile Amur sturgeon (Acipenser schrenckii) to osmoregulate and grow in saltwater. Hatchery-reared juveniles (mean weight 106.8 g, 5-month old) were transferred from freshwater to 10, 20, and 25 salinity saltwater over a period of 20 d. We measured the growth, serum osmolality, ion concentrations, and Na+/K+-ATPase activity. In addition, we prepared samples of gill tissue to quantify morphological changes in gill ultrastructure. Rearing in up to 25 saltwater for 30 d had no significant effect on growth. Similarly, serum osmolality and ion concentrations were similar to levels reported in other teleosts following acclimation to saltwater. Serum osmolality and Na+, Cl concentrations increased significantly with the initial increase in salinity. Afterwards, levels tended to stabilize and then decrease. Serum K+ levels did not change during acclimation to saltwater. Gill Na+/K+-ATPase activity increased initially as salinity was increased. However, the activity later decreased and, finally stabilized at 3.7±0.1 μmol Pi/mg·prot·h in 25 saltwater (1.6 times higher than the level in those in freshwater). In fish that were held only in freshwater, the chloride cells were located in the interlamellar regions of the filament and at the base of the lamella. Following acclimation to 25 saltwater for 30 d, the number and size of chloride cells increased significantly. Our results suggest that juvenile Amur sturgeon is able to tolerate, and grow in, relatively high concentrations of saltwater.  相似文献   

15.
An 8 weeks feeding experiment was conducted to determine the effect of dietary potassium on the growth and physiological acclimation of Pacific white shrimp(Litopenaeus vannamei) reared in diluted seawater(salinity 4). Six semi-purified practical diets containing 0.59, 0.96, 1.26, 1.48, 1.74, and 2.17+ g potassium K per 100 g diet were formulated, respectively. The survival and feed conversion rate did not show significant difference among groups of shrimps given these diets(P0.05). The shrimps fed the diets containing 0.96-1.48 g K+ per 100 g diet gained the highest weight, specific growth rate, and protein efficiency ratio. Their ammonium-N excretion rate as well as hemolymph concentration of Na+ and Cl- were significantly lower than those of the control(P0.05), but a reverse trend was observed for their gill Na+/K+-ATPase. Moreover, the shrimps fed with 1.48 g K+ per 100 g diet were the highest in hemolymph urea level, and the phenoloxidase and lysozyme activities were significantly higher than those of the control(P0.05). The growth and physiological response of the test shrimps suggested that diet containing 1.48 g K+ per 100 g diet improved the growth of L. vannamei in low-salinity seawater, and enhanced the physiological acclimation of the organism.  相似文献   

16.
Experiments were conducted to examine the effects of salinity fluctuation frequency on the osmolarity, Na+-K+-ATPase activity and HSP70 of Chinese shrimp Fenneropenaeus chinensis with initial wet body weight of 1.460 g ± 0.091 g. The salinity in the control group (D0) was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8...  相似文献   

17.
The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP content assay. Histopathological examination of gill, liver and kidney of exposed fishes showed that gill was a target organ of butachlor. The butachlor seriously impaired the respiration of gills by a series of lesions such as edema, lifting and detachment of lamellar epithelium, breakdown of pillar cells, and blood congestion. The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality. Antioxidant enzyme activity assay of the in vitro cultured flounder gill(FG)cells exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase(SOD), catalase(CAT)and glutathione peroxidase(GPX). Furthermore, along with the decline of antioxidant enzyme activities, ATP content in the exposed FG cells decreased, too. This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP. Similar decrease of ATP content was also observed in the exposed flounder gill tissues. Taken together, as in FG cells, butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells, which in turn resulted in the blood congestion and suffocation of exposed flounder.  相似文献   

18.
The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder,Paralichthys Olivaceus,was analyzed by histopathological examination,antioxidant enzymes activities and ATP content assay.Histopathological examination of gill,liver and kidney of exposed fishes showed that gill was a target organ of butachlor.The butachlor seriously impaired the respiration of gills by a series of lesions such as edema,lifting and detachment of lamellar epithelium,breakdown of pillar cells,and blood congestion.The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality.Antioxidant enzyme activity assay of the in vitro cultured flounder gill(FG) cells exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GPX).Furthermore,along with the decline of antioxidant enzyme activities,ATP content in the exposed FG cells decreased,too.This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP.Similar decrease of ATP content was also observed in the exposed flounder gill tissues.Taken together,as in FG cells,butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells,which in turn resulted in the blood congestion and suffocation of exposed flounder.  相似文献   

19.
1 INTRODUCTION Two large-scale concentration mechanisms, evaporation and freezing, have been proposed for marine origin brine production (Bein and Arad, 1992; Bottomley et al., 1999). There are three basic requirements for brine formation by seawater evap…  相似文献   

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