Climate Change and Geochemistry May Explain the Finding of Marine Cyanobacteria in a Continental Saline Lake     

Zorigto NAMSARAEV  Vladimir GORLENKO  Boris KUZNETSOV  Bair NAMSARAEV 《《地质学报》英文版》2014,88(Z1):158-159

正1 Introduction Alkaline Lake Khilganta located in a steppe zone of South Siberia(N 50°42'535,E 115°06'086)is unique among adjacent lakes because of a development of a thick(up to 3 cm)cyanobacterial mat dominated by  相似文献   

Cultural characteristics of chromium resistant unicellular cyanobacteria isolated from local environment in Pakistan     

Abdul Hameed Shahida Hasnain 《中国海洋湖沼学报》2005,23(4):433-441

Many unicellular cyanobacteria were isolated from different places： fields, ponds, polluted water, and soils from Muredkey and Kasur tannery areas, near Lahore, Pakistan. Different media like BG 11 medium, Bold Basal medium, Chu＇s # 10 medium and Gotham＇s medium, in standard forms and with slight variations of ingredients, and different pH, temperature and light regimes were checked for the optimum growth of the isolates. The isolation pro- cedure was repeated with different concentrations of chromium to select the resistant strains. These selected strains grew on chromium of the range 100-200 μg/ml in BG 11 medium. Cyanobacteria were maintained in solid and liquid media with/without shaking. Cyanobacterial strains were collected from natural habitats that were accompanied by a diversified group of organisms including bacteria, protozoan, and rotifers etc. In order to eliminate these agents termed as contaminants, we used several methods including phenol treatment, use of antibiotic and careful manual picking of unicellular cyanobacteria. Resistance of these strains against different heavy metals （ZnSO4, MnSO4, NiSO4, COCl2, Pb（NO3）3, CuSO4, HgCl2, AgNO3 and CdCl2） and antibiotics （erythromycin, streptomycin, kanamycin, chloramphenicol, neomycin） was evaluated. Optimum temperature was 30℃ with variable pH for the reduction of Cr^6＋ in to Cr^3＋ in majority of strains.  相似文献   

Isolation,purification and characterization of the hydrogen evolution promoting factor of hydrogenase ofSpirulina platensis     

Gu Tian-qing  Zhang Hui-miao  Sun Shi-hua 《中国海洋湖沼学报》1996,14(1):27-30

A component (s-factor) with obvious promoting effect on hydrogen evolution of hydrogenase has been isolated and extracted from a cell-free preparation ofSpirulina platensis. The effect of the s-factor in the reaction system is similar to that of Na₂S₂O₄, but is coupled with light. The s-factor has the maximum absorption peak at 620 nm in the oxidized state, at 590 nm in the reduced state. The partially purified s-factor showed two bands by SDS-PAGE and is distinctly different from phycocyanin, which has no change of oxidized state and reduced state absorption spectra, and also has no promoting effect on hydrogenase ofSpirulina platensis under the light. The research supported by the NSFC.  相似文献   

Siderophores from Marine Microorganisms and Their Applications   总被引：4，自引：1，他引：3  

LIJunfeng CHIZhenming 《中国海洋大学学报(英文版)》2004,3(1):40-47

1　Introduction　Ironisanessentialelementwhichisdifficulttoob tainduetoitslowsolubilityunderthephysiologicalconditions ,anditisalsothemostimportanttransitionmetalionfornearlyalllivingsystems.Manypatho genicbacteriausuallyobtainironfromtheiron bind ingprot…  相似文献   

广东省高州水库春季蓝藻水华成因初步探讨   总被引：12，自引：3，他引：9  

姚玲爱  赵学敏  周广杰  完颜华  蔡立梅  胡国成  许振成 《湖泊科学》2011,23(4):534-540

高州水库为广东省茂名市重要的饮用水源地,2009年和2010年春季相继出现蓝藻水华,给居民饮水带来安全隐患.对高州水库2009年和2010年春季水华情况进行分析,结果表明:两年浮游藻类细胞密度最高分别达4.08×107 cel1s/L和1.47 x 108cells/L,其中蓝藻所占比例分别为98.2%和98.7%,优...  相似文献   

全球变暖对淡水湖泊浮游植物影响研究进展   总被引：9，自引：6，他引：3  

邓建明  秦伯强 《湖泊科学》2015,27(1):1-10

全球变暖对湖泊生态系统的影响已经成为近年来湖沼学领域的研究热点.本文首先列举了目前研究全球变暖对淡水湖泊浮游植物影响的常用方法:监测数据分析、时空转换、遥感信息提取、控制实验、模型预测和古湖沼学技术等.研究结果表明气候变暖导致的气温升高、湖泊热力分层提前破坏以及无冰期提前等因素可导致春季物候提前;在全球变暖大背景下浮游植物群落结构正朝着蓝藻占优的方向发展,但是不同地区以及不同物种对全球变暖的响应不一致.在营养盐充足的湖泊中,由于全球变暖延长了浮游植物生长季节等,从而能提高浮游植物初级生产力;但在贫营养湖泊中,浮游植物初级生产力与变暖趋势甚至可能呈负相关.由于生态系统往往是多因子的共同作用,这也使得全球变暖对浮游植物群落的影响效应复杂化,区分各因子的净影响份额是目前研究的一个难点;全球变暖引起的风场改变会促进浅水湖泊中营养盐从底泥的释放,同时也会增加水体中悬浮物的浓度而影响水下光场,因此开展气候变化对再悬浮及浮游植物群落结构的影响可能是将来研究的一个切入点.  相似文献   

MODIS影像的大气校正及在太湖蓝藻监测中的应用   总被引：7，自引：0，他引：7  

李国砚  张仲元  郑艳芬  刘晓玫 《湖泊科学》2008,20(2):160-166

MODIS 数据有免费、波段丰富、时间分辨率高等优点,是进行太湖蓝藻监测的重要数据源,由于MODIS传感器接收的是地物反射太阳辐射的信号,太阳辐射与地球大气的相互作用会引起传感器接收到的信号失真,为了提高利用MODIS数据监测太湖蓝藻的精度,必须对其进行大气校正.本文介绍了FIAASH大气校正模型的基本原理,并对2007年4月25日MODIS数据的前七个波段进行试验,对比分析了影像大气校正前后的NDVI值以检测大气校正的效果;分析表明,大气校正前后NDVI的变化趋势基本上相同,但大气校正后的NDVI动态范围更大,校正后NDVI的平均值和标准差增大,大气校正在一定程度上有效地降低了大气对遥感影像的影响,达到了增强信息的目的;最后,利用大气校正获取的地表真实反射率数据的第二波段与第一波段的比值,运用阈值法提取蓝藻信息,经试验当阈值为1.9时提取出来的蓝藻分布图基本上与实际相符.利用MODIS影像可以快速、及时地监测蓝藻爆发的位置及爆发程度.  相似文献   

后生浮游动物摄食对太湖夏季微囊藻水华形成的作用     

周健  杨桂军  秦伯强  张光生  王丽君  高映海  李鸿毅  陈满意  钟春妮 《湖泊科学》2013,25(3):398-405

为了了解后生浮游动物的摄食作用在太湖夏季微囊藻水华形成中的作用,2009年7月15日至8月14日取太湖梅梁湾湖水开展了后生浮游动物对微囊藻水华形成作用的野外模拟实验.实验期间,未过滤掉后生浮游动物的对照组出现了漂浮在水面、肉眼可见的微囊藻水华,而过滤掉后生浮游动物的实验组没有出现微囊藻水华.结果显示,对照组整个实验期间都有后生浮游动物存在,共发现了9种后生浮游动物;而实验组在实验第6 d发现有后生浮游动物出现,整个实验期间共发现了3种后生浮游动物.浮游动物生物多样性分析显示对照组显著高于实验组.实验后期(21～30 d),对照组微囊藻平均密度显著高于实验组.整个实验期间,惠氏微囊藻(Microcystis wesenbergii)和水华微囊藻(Microcystis flos-aquae)密度均显著高于实验组,且惠氏微囊藻密度占对照组微囊藻总密度的60.79%.研究结果表明,太湖夏季后生浮游动物摄食并不能控制太湖蓝藻水华,相反,后生浮游动物特别是大型浮游动物能促进蓝藻水华的形成.同时表明,后生浮游动物群落结构可能是影响微囊藻水华形成的重要因素.  相似文献   

滇池蓝藻水华发生频率与气象因子的关系   总被引：6，自引：4，他引：2  

鲁韦坤  余凌翔  欧晓昆  李发荣 《湖泊科学》2017,29(3):534-545

蓝藻水华暴发是在一定的营养、气候、水文条件和生态环境下形成的藻类过度繁殖和聚集的现象,是水体环境因子(如总氮、总磷、pH值、溶解氧)和气象因子综合作用的结果.然而滇池周年性水华暴发标志着滇池蓝藻水华在当前水质条件下,气象因子为关键影响因子.为了进一步探究滇池蓝藻水华发生与气象因子的规律,本文利用2010-2011年滇池蓝藻水华遥感监测资料与周边地面气象站逐月资料,研究滇池蓝藻水华月发生频率与月气象因子的关系.结果显示,滇池蓝藻水华发生频率与平均气温、最低气温、平均风速、累计日照时数和降雨量等气象因子均表现为显著相关,其中与日照时数和风速呈显著负相关.各因子中与风速的相关系数最高,说明滇池各月蓝藻水华发生频率高低与风速关系最为密切,进一步验证了在具备蓝藻水华发生所需营养盐条件下,水体稳定性对蓝藻水华发生的影响更为重要的结论.以上结果可为科学预测蓝藻水华发生,并采取相应措施减少其带来的影响提供理论依据.  相似文献   

Biocrust landscape-scale spatial distribution is strongly controlled by terrain attributes: Topographic thresholds for colonization in a semiarid badland system     

Emilio Rodríguez-Caballero  José Raúl Román  Sonia Chamizo  Beatriz Roncero Ramos  Yolanda Cantón 《地球表面变化过程与地形》2019,44(14):2771-2779

Biological soil crust, or biocrust communities, are the dominating life form in many extreme habitats, such as arid and semiarid badlands, where water scarcity and highly erodible substrates limit vegetation cover. While climate, soil and biotic factors have been described as environmental filters influencing biocrust distribution in such biomes, little is known about the effect of terrain attributes on creating specific microhabitats that promote or restrict biocrust colonization. This study aimed to identify the main terrain attributes controlling biocrust distribution in the driest badland system in Europe, the Tabernas Badlands (SE Spain). To do this, we analysed the influence of different terrain attributes related to landscape stability and microclimate formation on the spatial distribution of lichen and cyanobacteria, using field measurements and topographical information from a LiDAR survey. Our results showed that the spatial distribution of cyanobacteria-dominated biocrusts, which are physiologically and morphologically adapted to extreme drought and high UVA radiation, was mostly associated with areas of high potential incoming solar radiation. The exception was bare south-aspect hillslopes with very high sediment transport potential, where bare physically crusted soils were the dominant ground cover. Lichen-dominated biocrusts, in contrast, colonized near the top of north-aspect hillslopes, characterized by low potential incoming solar radiation and potential evapotranspiration, and their cover decreased downstream, as conditions became good enough for vascular plants. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.  相似文献