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1.
研究了海水淡化浓排水中的金属铜对2种海洋微藻塔玛亚历山大藻和海洋原甲藻的影响。配制一系列含不同含量Cu2+的海水培养了2种海洋微藻,统计海藻生长过程中的藻细胞数量变化,做出不同Cu2+含量下海藻的生长曲线,了解Cu2+对海藻生长的影响;利用生物显微镜观察海洋微藻在不同Cu2+含量环境中的生存状况及细胞形态变化。结果表明,Cu2+含量的升高会一定程度上限制塔玛亚历山大藻的生长、繁殖和游动能力,而对细胞形态的变化影响较小;Cu2+的加入会对海洋原甲藻的细胞形态产生较大影响,但是随着培养时间的延续,则会对海藻的生长和繁殖起到一定的促进作用。  相似文献   

2.
随着全球气候变暖,极端天气的出现,正以不同的方式影响着海洋和沿海地区,对海洋生态系统产生了一定的影响。20世纪开始,全球平均温度上升0.7℃,最近气候预测表明,21世纪末,全球地面空气温度将升高1.1~6.4℃,从而会导致上层海洋变暖加剧。温度对海洋浮游植物的物种组成、光合性能以及生长速率都有着重要的影响。全球温度的升高促使了赤潮生物中适宜暖水的物种分布扩大,会进一步使赤潮的暴发窗口期变大以及提前。赤潮生物种类繁多,主要以甲藻、硅藻以及蓝藻等浮游生物为优势物种,暴发频率较多。研究温度对赤潮藻生理特性的影响对了解赤潮藻的暴发机制具有重要的影响。  相似文献   

3.
[目的]以江苏海州湾常见微藻塔胞藻(Pyramidomonas delicatula)、塔玛亚历山大藻(Alexandrium tamarense)为受试藻,研究水环境中草甘膦对2种微藻的致毒胁迫效应。[方法]以叶绿素a含量、超氧化歧化酶(SOD)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量为指标,研究2种海洋微藻的生长及细胞内抗氧化系统对草甘膦致毒胁迫的响应。[结果]草甘膦质量浓度高于6.15 mg/L,对2种微藻表现出明显抑制作用,塔胞藻、塔玛亚历山大藻10.25 mg/L组培养至7 d,分别为对照组的5.9%、6.4%;96 h培养时间内,草甘膦对塔胞藻及塔玛亚历山大藻叶绿素a含量的影响表现在降低叶绿素a的合成量,呈现显著的质量浓度-剂量效应;低质量浓度草甘膦对2种微藻的SOD活性均表现诱导性上升,在10.25 mg/L恢复对照组水平;草甘膦对2种微藻的CAT活性表现微弱抑制;2种微藻体内MDA含量随草甘膦处理质量浓度增加而显著增长,塔胞藻、塔玛亚历山大藻在10.25 mg/L试验组达最高值,均为对照组16倍之多。[结论]高质量浓度(≥6.15 mg/L)的草甘膦可以有效抑制海洋微藻抗氧化酶活性,对塔胞藻、塔玛亚历山大藻具有强烈的致毒效应,不同的海洋微藻对农药残留致毒胁迫的响应存在较大的种属差异性。旨在提示农药污染对水环境破坏的严重性,揭示海洋微藻作为环境毒理学评价指标的潜在应用。  相似文献   

4.
研究了灭藻剂对采自压舱水中的中肋骨条藻、拟菱形藻和裸甲藻三种赤潮藻的杀灭和控制作用。结果表明,这种化合物能有效地控制和杀灭实验所选的三种藻,且在反应2.0~2.5 h时间段,三种藻的灭藻率都达到80%以上,有效浓度为2.0 mg/L。实验表明,所选灭藻剂具有高效、作用时效长的特点,可能是一种比较理想的赤潮藻去除剂。  相似文献   

5.
不同氮磷水平下微小原甲藻对营养盐的吸收及光合特性   总被引:8,自引:0,他引:8  
研究了微小原甲藻对无机氮、磷的吸收特性和在室内批量培养条件下,无机氮、磷浓度对微小原甲藻生长和光合作用的影响. 结果表明,低氮(0.0882 mmol/L NaNO3)条件下,微小原甲藻具有最高的比生长速率,为0.46 d 1,而中氮(0.882 mmol/L NaNO3)条件下具有最大的细胞密度,为54900个/mL,分别比低氮和高氮(2.646 mmol/L NaNO3)下增加7.2 和20.1 . 随着培养基中磷浓度的升高,最大细胞密度和比生长速率也增加,在高磷(0.108 mmol/L KH2PO4)条件下达到最大值,分别为57400个/mL和0.45 d 1. 高营养源(高氮或高磷)状态下生长的藻细胞具有更高的单位细胞和单位叶绿素a表示的光饱和的光合作用速率(Pmchl a和Pmcell)和光饱和点. 低氮和高氮条件下的藻细胞同样具有高的单位细胞和单位叶绿素a表示的光合效率( chl a和 cell),而单位叶绿素a表示的光合效率( chl a)则在高磷下最大. 在氮源充足条件下,低的N/P有利于微小原甲藻细胞的生长.  相似文献   

6.
松节藻来源长枝木霉DL5-4化学成分及其生物活性研究   总被引:1,自引:0,他引:1  
对分离自大连海域松节藻的长枝木霉DL5-4进行大规模发酵培养,运用反相硅胶柱层析、半制备高效液相色谱、制备薄层层析、Sephadex LH-20凝胶柱层析、硅胶柱层析等手段对发酵粗提物进行分离纯化,得到11个单体化合物,并对其进行了结构鉴定和生物活性测试。通过~1HNMR、~(13)CNMR以及对比文献数据等鉴定其分别为cyclonerodiol(Ⅰ)、10(E)-cyclonerotriol(Ⅱ)、10(Z)-cyclonerotriol(Ⅲ)、epicyclonerodiol oxide(Ⅳ)、 cyclonerodiol oxide(Ⅴ)、trichoacorenol(Ⅵ)、 2α-hydroxy-harzianone(Ⅶ)、harzianone(Ⅷ)、 2′,3′-dihydrosorbicillin(Ⅸ)、 sohirnones A (Ⅹ)、sorbicillin (Ⅺ)。其中,化合物Ⅵ~Ⅺ对赤潮异弯藻、东海原甲藻、剧毒卡尔藻和海洋卡盾藻具有显著的抑制作用,化合物Ⅸ~Ⅺ对真菌围小丛壳有显著的抑制作用。  相似文献   

7.
菱形藻生长及运动状态对农药草甘膦原粉的毒性响应   总被引:1,自引:0,他引:1  
[目的]以淡水底栖硅藻(Nitzschia amplectens Hustedt)为受试藻,研究农药草甘膦原粉对其生长和运动状态的响应。[方法]以96 h EC50值、叶绿素a含量、运动状态等指标研究草甘膦对受试藻的毒性。[结果]草甘膦对受试藻96 h EC50值为29 mg/L;草甘膦对受试藻叶绿素a含量最大抑制率63.79%;运动状态随质量浓度增长受到抑制,2~5 d最明显。[结论]评价毒物对水环境的影响,浮游和底栖两类生物都应考虑在内。受试藻叶绿素a含量对草甘膦反应敏感。受试藻的运动状态可综合指示草甘膦毒性。  相似文献   

8.
通过氮浓度调节塔玛亚历山大藻毒素产量的初步研究   总被引:5,自引:0,他引:5  
初步研究了培养基中氮浓度及补加氮对塔玛亚历山大藻毒素产量的影响. 低氮(88.2 mmol/L)条件下藻细胞具有较高的比生长速率(0.60 d-1),是高氮(882 mmol/L)下的约1.2倍. 低氮下在藻细胞对数生长的末期(第10天)补加氮(至高氮水平)导致塔玛亚历山大藻的最大细胞密度(48.5′103 mL-1)明显增加,分别是低氮(6.28′103 mL-1)和高氮(21′103 mL-1)下的7.7和2.3倍;最大单位细胞毒素含量(1.26 pg/cell)和产量(43.51 mg/L)分别是低氮(1.09 pg/cell和6.49 mg/L)和高氮(0.88 pg/cell和13.18 mg/L)下的1.2, 1.4倍和6.7, 3.3倍. 结果显示,在培养基中低水平氮、磷条件下塔玛亚历山大藻细胞的毒素合成增加,其中特别是磷限制条件下,藻细胞的毒素含量增加更为显著. 通过低氮下补加氮源以维持培养基中的低氮水平,可以显著促进塔玛亚历山大藻细胞的毒素产量.  相似文献   

9.
选择三种海洋微型藻,叉鞭金藻、扁藻和塔玛亚历山大藻,在自行研制的光生物反应器中进行人工培育繁殖,采用不同光照强度和搅拌速度,测试光生物反应器应用于海洋微藻人工培育的效果。研究结果表明:这三种海洋微型藻在研制的生物反应器中细胞均能快速分裂增长,细胞增殖的浓度比在自然条件培养的同种藻的细胞增殖浓度要高1-2倍。并验证该光生物反应器的光照强度和搅拌强度可以根据微藻实际生长需要而调整到最佳状态,扁藻、叉鞭金藻、塔玛亚历山大藻分别在光照强度10000Lx±300Lx、5000Lx±300Lx、3000Lx±300Lx时生长最好。高转速和连续搅拌不利于塔玛亚历山大藻细胞增殖,增殖慢、藻浓度不高。  相似文献   

10.
耐酸性和耐高浓度CO_2的海洋微藻筛选   总被引:1,自引:0,他引:1  
用于固定工业烟道气CO_2的微藻必须具有耐酸性和耐高浓度CO_2的能力.本研究拟从12种常见海洋微藻中筛选出耐酸和耐高浓度CO_2的种类.首先采用微板吸光法测定了微藻在不同pH值的F/2培养基中的藻细胞密度变化,比较了各种微藻对H_2SO_4和HNO_3所致酸性的适应能力;将耐酸性较强的微藻接种到培养基中,以75 mL/min的流量连续通入体积分数为5%的CO_2,并以通入空气的培养基中生长的微藻为对照,根据培养7d期间藻细胞密度和生物量的变化趋势,进一步筛选得到耐受高浓度CO_2的藻种.结果表明,12种供试微藻中,以杜氏盐藻(Dunaliella tertiolecta)、钝项螺旋藻(Spirulina platensis),海水小球藻(Chlorella pacifica)和小新月菱形藻(Nitzschia aosterium)的耐酸性较强,均可在pH=4的培养基中正常生长;而小新月菱形藻和海水小球藻同时能够耐受高浓度CO_2冲击,培养结束后,5%CO_2处理组的藻生物量分别达到对照组的107.62%和113.43%.因此,小新月菱形藻和海水小球藻在固定工业CO_2和减缓温室效应方面具有较好的应用潜力.  相似文献   

11.
A novel technology was developed to prepare microencapsulated red phosphorus (RP) with a coating of melamine cyanurate (MCA) serving as both a nitrogen‐containing flame retardant and as a solid lubrication agent. We took advantage of the self‐thickening effects during the MCA self‐assembly process to realize effective encapsulation on the surface of predispersed RP powder. The technology described in this article can overcome several drawbacks of current microencapsulation processes including (1) relatively complicated preparation processes, (2) use of formaldehyde or other noxious modifiers, and (3) poor compatibility with flame retardant fillers and polymer matrix resulting in poor physical properties. Additionally, this novel technology can also modify various properties of RP with regard to lubrication performance, ignition point, moisture absorption ratio, and color. As a composite system of flame retardant phosphorus encapsulated by a nitrogen‐containing flame retardant, the microencapsulated RP showed nitrogen‐phosphorus (N‐P) synergism with further improved flame retardancy. The action and mechanisms of the microencapsulated RP flame retardant polyamide 6 (PA6) were investigated by limiting oxygen index, vertical burning experiment (UL94), thermogravimetric analysis, and scanning electron microscope observations. The results indicated that the flame retardant PA6 possessed desired flame retardancy because of effective char‐formation of the condensed phase and it also showed satisfactory mechanical properties as the result of the good compatibility between flame retardant and PA6 resin. POLYM. ENG. SCI., 46:1548–1553, 2006. © 2006 Society of Plastics Engineers  相似文献   

12.
In order to ascertain the taxonomic status of the Ariake Sea population of Japanese grenadier anchovy, Coilia nasus, and assess the contemporary possible genetic barrier between the west and east coastal waters of the East China Sea, we used amplified fragment length polymorphism (AFLP) markers to detect the genetic structure of C. nasus, in the East China Sea and Yellow Sea. Eighty-one individuals of C. nasus were collected from five locations and 12 individuals of Coilia mystus were sampled from the Yangtze River Estuary. A total of 371 loci were detected by five primer combinations, 310 of which were polymorphic (83.56%). Analysis of molecular variation (AMOVA) and pairwise fixation index (FST) revealed significant genetic differentiation among five samples, indicating limited gene flow among populations. The dendrogram for populations by neighbor-joining (NJ) cluster analysis provided evidence of a clear relationship between genetic and geographic patterns, supporting significant genetic differentiation between China coastal populations and Ariake Sea populations. Compared to the genetic divergence between C. nasus and C. mystus, the level of genetic differentiation between China and the Ariake Sea populations of C. nasus is obvious below the species level, indicating isolated populations of C. nasus in the Ariake Sea. Isolation by distance analysis revealed that direct ocean distance with deep-water at the continental slope and high salinity between west and east coastal waters of the East China Sea served as major physical barrier to C. nasus, supporting the coastal dispersal pattern in this estuarine species, and rejecting offshore dispersal strategy.  相似文献   

13.
流量分配比对改良A/O分段进水脱氮除磷特性的影响   总被引:4,自引:0,他引:4  
采用改良A/O分段进水工艺处理我国南方低浓度、低碳氮比城市生活污水。在进水COD/TN为5.16,HRT为8.7 h,SRT为15 d,MLSS为5.66 g·L-1,污泥回流比为75%,厌氧/缺氧/好氧体积比为4∶8∶10条件下,通过设置6种不同进水流量分配比,控制各好氧段DO为1~1.5 mg·L-1,经过150 d的连续运行,得到系统最佳流量分配比为20%∶35%∶35%∶10%;在此工况下COD、氨氮、总氮、总磷出水水质分别为33.05 mg·L-1、0.58 mg·L-1、9.26 mg·L-1、0.46 mg·L-1,出水优于国家GB 18918-2002一级A排放标准。原水COD绝大部分作为厌氧释磷和反硝化脱氮所需碳源,系统对碳源有效利用率达74%;DO和ORP 的协同控制可以作为系统厌氧放磷段的控制参数;同时亦可作为缺氧段反硝化完成和好氧段硝化完成的指示性参数。  相似文献   

14.
为了提高脱氮除磷的效率,采用序批式生物反应器(SBR)工艺处理模拟生活污水,考察了不同温度下N/P、污泥龄(SRT)对厌氧/好氧/缺氧序批式生物反应器(AOA-SBR)工艺同步脱氮除磷效能的影响。结果表明:当温度为10 ℃、N/P为2~3、SRT为20 d时,NH4+-N、TN和TP去除率分别为78%、69%和56%,污泥产率YS为0.339 kgSS/(kgBOD5),污泥含磷率PC为4.68%。当温度为25 ℃、N/P为3~5、SRT为15 d时,NH4+-N、TN和TP的去除率分别为88%、83%和91%,污泥产率YS为0.253 kgSS/(kgBOD5),污泥含磷率PC为6.35%。当温度为35 ℃、N/P为5~7、SRT为10 d时,NH4+-N、TN和TP去除率分别为80%、66%和73%,污泥产率YS为0.225 kgSS/(kgBOD5),污泥含磷率PC为7.42%。污泥产率YS随着温度和污泥龄的增加而降低,通过调节温度和污泥龄能够实现污泥减量。  相似文献   

15.
Knowledge of speciation and transformation of phosphorus (P) in soil following high application rates of chemical and organic fertilizers is essential for improving P management in Chinese agricultural ecosystems because P fertilizers have been increasingly overapplied in China. Phosphorus speciation of the soil in three long-term fertilization experiments established in 1990 was investigated jointly with a sequential fractionation scheme and P K-edge X-ray absorption near edge structure (XANES) spectroscopy. Both chemical fractionation and XANES spectroscopy confirmed that P species in the topsoils (0–20 cm) were mainly composed of iron phosphate, calcium phosphate and organic P, regardless of soil pH and mineralogy. The continuous application of nitrogen, phosphorus and potassium fertilizers (NPK) had little effect on the distribution of P species in the topsoils compared with that in the control and 1990 baseline topsoils. In contrast, the application of NPK plus organic manures (MNPK) changed significantly the speciation distribution of P by increasing distinctly available P in the soil. The transportation and transformation of P species depended on soil properties including P levels, organic carbon concentrations and mineral types. The long-term application of MNPK facilitated the transportation of P into lower horizons and the accumulation of organic P in the soil. The XANES results provided spectroscopic support for the P species identified by the fractionation scheme, and the combination of the two techniques provided complementary information on the speciation and transformation of P in soil.  相似文献   

16.
Soil phosphorus (P) deficiency is a major factor limiting crop productivity in many tropical and subtropical soils. Due to the acidic nature of these soils, rock phosphate (RP)-based P fertilizers that are cheaper than manufactured water-soluble P fertilizers can be an attractive alternative under certain conditions. Assessment of the efficacy of these alternative P fertilizers and a rational management of local P resources for sustainable agricultural production require an understanding of the dynamics of P in the soil–plant system and the interactions of various P sources in soils and monitoring of soil available P levels. The present work was conducted to test the applicability of the 32P isotopic kinetic method to assess the soil P fertility status and evaluate the agronomic effectiveness of local rock phosphates in subtropical China. A series of experiments was carried out in the laboratory, greenhouse and field conditions with the following specific objectives: (a) to evaluate the suitability of this isotopic kinetic method in evaluating soil P fertility in 32 soil samples collected across southern China, (b) to test and further develop chemical extraction methods for routine soil P testing, (c) to monitor the dissolution kinetics of local low to medium grade rock phosphate sources and their effect on soil properties and (d) to evaluate their agronomic effectiveness in greenhouse and field experiments. Since most of the studied soils had very low concentrations of soluble P and high P-fixing capacities, the isotopic kinetic method was found unsuitable for evaluating soil P fertility and to predict plant P uptake. In contrast, the proposed chemical extraction method (NaHCO3-NH4F) predicted very well plant P uptake, suggesting that this extraction method can be routinely used to evaluate soil bioavailable P in similar soils in subtropical China. From the incubation study, it was found that although the local low to medium grade RPs were inferior to the reactive NCPR in increasing soil available P levels, they have the potential to improve soil chemical properties. Field experiments indeed demonstrated that the medium grade Jinxiang RP significantly increased crop yield, suggesting that local low to medium grade RPs could be used as P sources to provide P to plants and also to improve soil chemical properties. Overall, these results provide important information for a rational management of P resources for sustainable agriculture in subtropical China.  相似文献   

17.
为了提高污水脱氮除磷的效率,研究采用序批式反应器(SBR工艺)厌氧、好氧和缺氧(AOA)的运行方式富集反硝化聚磷菌(DPB),实现同步脱氮除磷。结果表明:在好氧段投加甲醇作为碳源(25—40 mg/L)可有效抑制好氧吸磷,对硝化反应影响较小,能够在缺氧段实现同时反硝化脱氮除磷。SBR反应器稳定运行10个月,当进水NH4+-N、PO43--P分别为30,15 mg/L时,总氮(TN)和PO43--P的平均去除率分别为82.5%和92.1%。聚磷菌能够利用硝酸盐作为电子受体,DPB占总聚磷菌的比例达到44.8%。与A2O运行方式相比,AOA运行方式更有利于实现DPB的富集。  相似文献   

18.
The large yellow croaker (Larimichthys crocea) is the most important mariculture fish species in China and the wild stocks of this croaker have collapsed in the past decades due to high fishing pressure and habitat degradation. Due to a lack of wild croaker samples, however, studies concerning the genetic changes of the cultured croaker stocks compared to their wild counterparts were never conducted. Here, we collected three wild populations in the northern and central East China Sea during fisheries survey and investigated the differences in terms of genetic diversity and differentiation between and within cultured stocks and wild populations. Our results demonstrated that the cultured croaker had significantly reduced genetic diversity in contrast to the wild populations, and also presented statistically significant differentiation from the wild, indicating that enhancement of the current wild stock should be conducted with caution. These changes may be caused by founder effects, artificial selection and random genetic drift. With a relatively high level of genetic diversity, the wild populations showed important value for improving the ongoing breeding program of this croaker. Further, we detected no differentiation among the wild populations, suggesting that the wild croaker in the northern and central East China Sea should be considered as one unit for management and conservation.  相似文献   

19.
To re-evaluate ecological effects of kelp culture in marginal seas, the silica body content in kelp cultured in the East China Sea and the carbon content in the silica body extracted from kelp were measured. The silica body content in kelp cultured in the sea ranged from 0.20 to 0.60 % and the carbon content in the silica body extracted from kelp was 0.27 ± 0.06 %. The carbon sequestration rate in silica bodies extracted from kelp cultured in the East China Sea was 2.47 ± 0.40 t.a?1 from 2000 to 2011. In the East China Sea, the production of the silica body of kelp in the kelp culture zone was 6.56 ± 1.06 g.m?2.a?1. The carbon sequestration rate in the silica body of cultured kelp in the East China Sea was 0.02 ± 0.00 g.m?2.a?1, which accounted for 1.43 % of CO2 flux from air to sea. The carbon fixed in the silica body extracted from kelp might be one part of the missing carbon sink. Considering carbon content in silica bodies extracted from kelp cultured in the East China Sea, carbon sequestration of kelp culture in the marginal sea should be re-evaluated and some missing carbon sinks caused by anthropogenic factors might be reduced.  相似文献   

20.
A pot experiment with two lateritic soils measured the relative residual effectiveness (RRE) of superphosphate and three rock phosphate (RP) fertilizers applied six years previously in the field. Three plant species (lettuce, wheat and maize) having very different external P requirements were grown as indicators of P availability. Superphosphate had the maximum RRE (1.0) and low reactive Queensland RP had the minimum RRE (0.04–0.45) for all plant species. For one soil the RRE of reactive North Carolina RP was similar to that of superphosphate (0.87–1.04), but ranged from 0.07 to 0.30 for the other soil. The RRE of Calciphos (one soil only) ranged from 0.60 to 0.98 for all plant species.The RRE of rock phosphate decreased for the three crops in sequence maize> wheat> lettuce for a 30 days growth period. This ranking follows the increasing external P requirement of the three plant species. Very high rates of application of RP may have induced micronutrient deficiencies.  相似文献   

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