排序方式： 共有58条查询结果，搜索用时 15 毫秒
41.
Tatyana A. Zotina Alexander P. Tolomeyev Nadezhda N. Degermendzhy 《International Journal of Salt Lake Research》1999,8(3):211-232
The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12--15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed. 相似文献
42.
海洋浮游细菌在海洋生态系统的运行中起着关键性的生物地球化学作用。利用2010年夏季第4次北极考察获得的白令海不同深度水样,运用变性梯度凝胶电泳技术以及克隆建库等方法,来了解白令海中浮游细菌的多样性和群落组成等信息。结果表明:在白令海海盆区B07站位的50 m处,其浮游细菌的香农多样性指数是最高的,为2.61;香农多样性指数最低的是B07站位的3 m处,为1.99。白令海海盆区的细菌多样性变化比陆架区要大,有可能与海洋环境的复杂变化有关。通过克隆测序,鉴定出的浮游细菌类群分为4大类：α-变形杆菌、β-变形杆菌、γ-变形杆菌和拟杆菌。其中γ-变形杆菌所占的比例最大,为53%,是白令海中的优势种群;拟杆菌其次,为37%。这些浮游细菌在白令海中的分布情况为：γ-变形杆菌和拟杆菌存在于3个位点的所有水层中,α-变形杆菌只存在于B07站位的50m和100 m水层中,β-变形杆菌除B13站位的0 m处外,存在于其他站位的所有水层中。白令海B断面3个站位的温度随着深度的增加而降低,盐度随着深度的增加而升高。大体上白令海海盆区（B07站位）的硝酸盐、磷酸盐和硅酸盐浓度比陆架区（B15和B13站位）高,陆架区的铵盐浓度较海盆区高。 相似文献
43.
The Institute of Biology investigations of morphological diversity of bacteriae with the aid of electronic microscopy are used for the purposes of ecological monitoring. The results obtained allow to recommend this method to be widely applied.It has been demonstrated that for oligotrophic lake Baikal microflora consists mainly from ultra-microscopic cocci. Where the river Selenga inflows into Baikal morphological diversity of bacteriae is much wider. Bacterioplankton of Irkutsk reservoir by morphological characteristics is very similar to one of lake Baikal In meso-eutrophic Bratsh reservoir bacteriuplankton is more morphologically diversified. There are flexibacteriae, vibrios. Caulobacter sp. cells occurring in its water body.In the places of waste waters'' income to river. Angara morphological diversity of bacteriae is high and various forms with projections etc. can be observed. 相似文献
44.
太湖浮游细菌种群基因多样性及其季节变化规律 总被引：8，自引：3，他引：5
为认识湖泊中浮游细菌的多样性及其变化规律,本研究采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)的方法,研究了太湖梅梁湾和湖心区浮游细菌种群16S rRNA基因多样性以及种群基因组成的季节变化特征.研究结果表明,太湖浮游细菌种群具有丰富的基因多样性.浮游细菌的丰度、DGGE条带数、种群的Shannon-Wiener指数、Simpson 指数和Pielou指数均呈现显著的季节变化规律:夏季及秋季浮游细菌的丰度、基因多样性及种群的均匀度较高,而冬季和春季则较低.浮游细菌种群的基因组成随时间变化.梅梁湾浮游细菌的丰度显著高于湖心.梅梁湾与湖心浮游细菌主要建群种的基因型存在显著差异. 相似文献
45.
浮游细菌在驱动湖泊物质循环、指示湖泊水环境质量等方面发挥重要作用,探明其在湖泊中的空间分布格局及其驱动机制,是揭示湖泊物质循环过程及水环境状况的关键。浅水湖泊具有水动力扰动强烈的生境特点,其中的浮游细菌群落空间格局的形成机制尚未明晰。本研究以大型浅水湖泊——太湖为研究对象,通过对全湖开展系统的野外调查,结合高通量测序技术、多元统计分析方法及生态学模型构建,系统探明太湖浮游细菌的空间分布格局,并揭示格局形成的驱动机制。结果显示：（1）太湖西北部湖区（藻型湖区）与东南部湖区（草型湖区）之间浮游细菌群落结构存在显著差异,而这两个区域内各湖区间及湖心区与周边湖区间之间的浮游细菌群落结构差异不显著,太湖浮游细菌群落结构整体上呈现较弱的距离衰减规律;（2）太湖草、藻型湖区及湖心区中浮游细菌群落结构分别与叶绿素a、透明度及总悬浮物显著相关,总体上环境变量对太湖浮游细菌群落空间格局的相对贡献率大于空间变量;（3）尽管确定性过程中的异质化选择、随机过程中的非主导性过程以及扩散限制对太湖浮游细菌空间格局的形成均产生重要影响,但总体上随机过程对格局形成的相对贡献更大;（4）太湖无序风场驱动的水力混合作用导致... 相似文献
46.
Use of inhibitors for coastal bacteria and phytoplankton: Application to nitrogen uptake measurement
Aurore Trottet Eric Fouilland Christophe Leboulanger Elodie Lanouguère Marc Bouvy 《Estuarine, Coastal and Shelf Science》2011
For several decades, prokaryotic and eukaryotic inhibitors have been used to exclude bacteria from microalgal cultures and for investigating prey-predator relationships. Recently there has been considerable interest in using specific inhibitors for studying the interactions between bacteria and phytoplankton, by selective repression of either organism’s activity. The effectiveness of chemical inhibitors must be tested before applying them to natural communities to partition metabolic activities between functional groups. Six different antibiotics selected from the most commonly reported in the literature were tested, at concentrations varying from 12.5 to 100 mg L−1, for their effect on bacterial growth and functional diversity of natural communities from Mediterranean coastal waters. Penicillin and streptomycin each at a final concentration of 100 mg L−1 significantly reduced bacterial growth within 2 h. There was a greater impact on bacterial functional diversity when both antibiotics were mixed together. This mixture did not have any significant effect on the growth of selected cultured phytoplankton strains, whereas the eukaryote inhibitor cycloheximide at 100 mg L−1 reduced growth within 2 h of incubation. The penicillin–streptomycin mixture and cycloheximide alone successfully partitioned NH4+ and NO3− uptake between bacteria and phytoplankton bi-weekly sampled in a coastal lagoon in Autumn, where bacterial contribution to total NH4+ and NO3− uptake averaged 46 and 41%, respectively. The use of specific inhibitors may be a valuable method for studying interactions, such as competition and mutualism, or lack of interaction between the different components of microbial communities and could be used to study their relative importance in biogeochemical fluxes. 相似文献
47.
大鹏湾浮游细菌时空分布与环境因子的关系 总被引：6，自引：0，他引：6
应用荧光显微镜计数法,研究了大鹏湾海域细菌丰度时空分布特征,探讨了其与温度、溶解氧、叶绿素a、氨盐、硝酸盐和磷酸盐之间的关系.结果表明,大鹏湾全年细菌丰度介于1.40x10<'8>-24.43x10<'8>个L<'-1>之间.各季节细菌丰度高低依次为:夏季、春季、秋季、冬季.浮游细菌的水平分布呈现近岸较高、离岸逐渐减少,自大鹏湾西部湾顶向东部湾口逐渐减少的特征.除了夏季,温度与浮游细菌呈显著正相关(P<0.05),是浮游细菌的主要控制因子;溶解氧与浮游细菌全年呈显著负相关(春、夏季P<0.01,秋冬季P<0.05);叶绿素a除了春季外其他季节与浮游细菌相关性非常显著(P<0.01),是浮游细菌的主要调控因子;无机营养盐中,氨盐和磷酸盐全年与浮游细菌丰度呈高度显著正相关(P<0.01):对浮游细菌丰度具有调控作用,硝态氮在冬季对浮游细菌丰度有显著调控作用. 相似文献
48.
黄海西北部浮游细菌生物量分布特征及其与环境因子的关系 总被引：3，自引：0，他引：3
分别研究了2006年7月(夏季)和2007年1月(冬季)、5月(春季)、10月(秋季)黄海西北部海域浮游细菌生物量的分布特征,探讨了它们与温度、盐度和Chl a含量之间的关系.结果表明,研究海区平均细菌生物量春、夏、秋和冬季分别为:41.083,8.34,16.68和6.20 mg/m3.4个季节表层细菌生物量分布均呈现出从辽东半岛近岸区域向外海逐渐降低的趋势.春、秋季除浮游植物Chl a外各生态因子与细菌生物量之间均无显著性相关关系.夏、冬季与温度、盐度和Chl a含量的相关性均不显著. 相似文献
49.
The number and lipolytic activity of neustonic and planktonic bacteria inhabiting estuarine Lake Gardno were determined. Lipolytic bacteria were very numerous in investigated layers of water, accounting for 10–88% of the total number of culturable heterotrophic bacteria. Significant differences were found in the decomposition of individual lipid substrates by bacteria. The highest percentage of neustonic and planktonic strains were able to hydrolyse tributyrin and Tween 85. The least numerous bacteria group was microflora hydrolysing Tween 20 and Tween 40. The activity of lipases synthesized by bacteria from the subsurface layer was higher than that of lipases produced by bacteria isolated from the surface layers. A significant effect of salinity on the activity of lipases has been shown. 相似文献
50.
Observations of the short-term changes of seawater bacterioplankton were carried out during the summer of 1988 in Antarctic coastal surface waters. The studies were designed to compare the variations of bacterioplankton in freemoving and enclosed seawater. Even when a diurnal cycle is present the data collected from the enclosed seawater experiments remain much more constant than the corresponding data in free-moving seawater. The wide range of parameters used in the two experiments reveals common properties which illustrate the major role of displacements of water masses at a fixed sampling station in the temporal changes observed in free-moving Antarctic coastal seawater. 相似文献