海洋石油降解菌深海弯曲菌的种类多样性及地理分布特征分析          下载免费PDF全文

刘仁菊  董纯明  李登峰  邵宗泽 《应用海洋学学报》2017,36(4):565-574

深海弯曲菌(Thalassolituus)是一类海洋专属的石油降解菌.为认识其多样性与地理分布、获取石油降解菌资源,本研究对西太平洋和厦门近海的表层海水分别通过石油烃富集和直接涂布石油烃平板,对获取的菌株进行了分离鉴定.在此基础上,对Gen Bank数据库中该属的可培养和未培养菌株信息,进行了系统进化与物种多样性分析.结果表明,从西太富集菌群分离得到的32个菌株中,主要优势菌为假单孢菌(Pseudomonas)和海杆菌(Marinobacter);其次是食烷菌(Alcanivorax)和弧菌(Vibrio).深海弯曲菌仅有2株,但它们代表1个潜在的新种,它们与模式菌株T.marinus IMCC1826T的同源性仅为96.9%和97.0%.从厦门表层海水中分离到1株深海弯曲菌,与模式菌株T.marinus IMCC1826T的相似度为99.66%.基于本研究分离菌株及Gen Bank可培养及未培养菌株的16S rRNA基因序列开展的系统发育分析表明,该属存在3个明显的进化分支,即2个模式种T.oleivorans与T.marinus分别代表的2个分支和1个独立分支;此外,不同分支呈现明显的地理分布特征,即来自同一纬度范围的菌株或序列多聚类于同一分支中.我们推测,深海弯曲菌在进化过程中,可能因适应不同纬度海域的温度等环境因子,逐步进化出3个不同环境适应性的分支.本研究加深了对深海弯曲菌在不同温度海洋环境中种类多样性分布特征的认识,为海洋石油污染生物修复提供了新资源.  相似文献   

沱江沉积物-水界面磷形态垂向分布及时空变化特征     

徐青  刘霞  余晓平  郭亚飞  邓天龙 《岩矿测试》2019,38(6):668-680

水体中富营养化水平与磷元素的赋存形态密切相关。目前围绕引起富营养化关键因子之一的磷形态的垂向分布特征、各磷形态间的迁移转化行为及其影响因素取得了比较明确的研究进展。为进一步揭示不同磷形态在沉积物-水体系中迁移转化行为随时空的变化特征,本文采用磷钼蓝分光光度法对沱江流域简阳段间隙水中可溶性活性磷(SRP)、可溶性非活性磷(SUP)及总溶解性磷(TDP)进行测定;采用SMT法和改进的沉积物无机磷形态连续提取法对沉积物中总无机磷(TIP)、总磷(TP)、难提取磷(Res-P)、可交换态磷(Exc-P)、铁结合态磷(Fe-P)、铝结合态磷(Al-P)、钙结合态磷(Ca-P)进行提取,磷钼蓝分光光度法进行测定,以揭示沉积物-水体系中磷的赋存形态垂向分布行为特征,并将实验数据与十年前该地区磷的赋存形态结果进行对比,探讨磷赋存形态的变化趋势及影响因素。结果表明:间隙水中SRP、SUP和TDP的含量分别为0.004～0.36mg/L、0.080～3.19mg/L和0.056～3.28mg/L;沉积物中TP、TIP、Res-P、Exc-P、Al-P、Ca-P含量分别为1235.40～1646.94mg/kg、860.00～1318.59mg/kg、130.31～537.13mg/kg、1.35～14.10mg/kg、0.007～0.12mg/kg、743.13～1109.91mg/kg,Fe-P未检出。对比十年前后沉积物-水体系中磷赋存形态的变化可知,由于受到外源磷输入的影响,间隙水中SRP、SUP以及TDP含量虽然在-10cm以上变化不明显,但在-10cm以下明显增大,且导致沉积物中TP、TIP含量增加;偏碱性的沉积环境导致Al-P的释放,其含量明显减小;Exc-P含量的减小与其转化为稳定的Ca-P或Res-P形态有关。研究认为:随着时空的变化,沱江简阳段沉积物呈现外源磷输入和内源磷释放的综合污染。总体而言,由于输入的磷形态大部分以稳定的Ca-P和Res-P形态存在于沉积物中,使得表层间隙水中生物可直接利用的磷含量总体变化不大,该地区富营养化程度不会加重。维持沉积环境的弱碱性,有利于Al-P、Exc-P等向Ca-P的有效转换,抑制河流富营养化。  相似文献   

科尔沁沙地植被恢复过程中群落组成及多样性演变特征     

詹瑾  韩丹  杨红玲  李玉霖 《中国沙漠》2022,42(2):194-206

流动沙丘、固定沙丘和沙质草地均是科尔沁沙地土地沙化的产物,植被恢复重建则是该区域流沙治理的主要措施,理解植被恢复过程中群落组成及植物多样性演变特征有利于沙地植被恢复和生态重建.本研究基于连续15年对科尔沁沙地流动沙丘、固定沙丘和沙质草地长期植物群落结构调查数据,分析了 3种沙地类型植物群落年际变化特征及不同生活型植物年...  相似文献   

Length frequency analysis ofPleuragramma antarcticum,Electrona antarctica,Protomyctophum bolini     

Liu Qun  Chen Da-gang 《中国海洋湖沼学报》1995,13(4):380-384

British Antarctic Survey (BAS) data collected near the Antarctic Peninsula area were used in this 1988/1989 study on the length frequency of three Antarctic fish species (Pleuragramma antarcticum, Electrona antarctica and Protomyctophum bolini) showing that the standard length (SL) ofP. Antarcticum ranged from 26.0 mm to 161.0 mm, that the 26.0 mm to 54.0 mm SL juveniles could be considered to be the age group 1 fish, and that the SL ofE. antarctica ranged from 39.4 mm to 89.7 mm for the males and 48.0 mm to 118.0 mm for the females, which may contain at least 6 age groups. This is more than previously thought.P. Bolini had 29.2 mm to 60.2 mm SL and complicated age composition.  相似文献   

江西临川茅排地区金表生地球化学作用研究     

张卫民  史维浚  周文斌 《华东地质学院学报》1996,(1)

本文从水文地球化学角度研究了金的表生地球化学作用，并应用热力学方法计算了茅排地区水中金的存在形式，研究了水溶金的迁移和沉淀条件，得出了一个重要结论：是该区水中金的主要存在形式。在此基础上初步探讨了砂金矿的形成条件。  相似文献   

The current status ofAtriplexon the Cape Verde Islands     

N.M. Pasiecznik  M.T. Vera-Cruz  P.J.C. Harris 《Journal of Arid Environments》1996,34(4):507-519

Extensive areas of low lying coastal plains on Santiago Island, Republic of Cape Verde, are virtually devoid of natural vegetation. Of many introduced trees and shrubs, onlyAtriplexspecies have been found to thrive. Several plantations have been established during the past 15 years by the Cape Verde Government, FAO and other agricultural development groups. Results from these, together with local perceptions, indicate that although growth and survival are good, the primary objective of providing forage is not being met, owing to the unpalatability ofAtriplexto local stock. In recent field trials, severalAtriplexspecies showed good growth, but none were browsed and survival was quite poor, with onlyA. undulata(65%) andA. canescens(100%) exceeding 60% survival. Forage analysis identified high salt content in all species tested, and the highest protein content was found inA. glauca(16%),A. vesicaria(17%) andA. canescens(20%), which also had the lowest salt levels.Atriptex canescenswas identified as worthy of further introduction. An establishedA. halimusplantation that was observed to be browsed was compared to unbrowsed stands in terms of forage, soil and local drinking water analyses. Possible reasons for the unpalatability ofAtriplexto local stock and its resolution are discussed, along with the potential future ofAtriplexon the Cape Verde Islands.  相似文献   

Analysis of raudhas vegetation in central Saudi Arabia   总被引：2，自引：0，他引：2  

K. H. Shaltout  M. A. Mady 《Journal of Arid Environments》1996,34(4):441-454

The present study analyses the vegetation of three raudhas in central Saudi Arabia (Kharj, Khuraim and Binban). Seventy-five stands were examined and the martrix of 68 species × 75 stands, based on species cover data, was classified using TWINSPAN and ordinated using DECORANA. Eleven vegetation groups were generated: one dominated byHammada elegansand five dominated byAcaciaspp. (A. iraquensis, A. elatior, A. seyal, A. tortilis-Ziziphus spina-christi-Rhazya strictaandA. abyssinica). TheAcaciaspp. communities represent the climax stage of the xerophytic vegetation in Saudi Arabia and have, in most cases, high species cover and low species diversity. Another five groups are dominated, fully or partly, by species that often inhabit disturbed areas (Prosopis juliflora, Heliotropium bacciferum-Tamarix arabica-Prosopis juliflora-Pulicaria crispa, Ziziphus spinsa-christi-Lagonychium farctum-Alhagi maurorum-Cynodon dactylon, Salsola imbricataandBassia eriophoria-Chloris virgata-Zygophyllum coccineum-Seidlitzia rosmarinus). Many of these groups have low species cover and relatively high species diversity. The effects of environmental factors and human impact on species diversity and abundance of these communities were assessed.  相似文献   

Comparison of the Concentrations of Chemical Components in Cloudwater Samples Collected during Four Different Field Campaigns     

F. Deutsch  P. Hoffmann  H. M. Ortner 《Journal of Atmospheric Chemistry》2001,40(3):295-304

In this study, the results of four different field experiments concerning the speciation of iron and the concentrations of some other chemical compounds in cloudwater samples are compared to one-another. Hydrogen peroxide concentrations were higher during campaigns, conducted at sites not much influenced by anthropogenic emissions as compared to those conducted at more polluted areas. In contrast, percentages of S(IV) in the cloudwater were lowest at the rural sites and highest at the sites polluted by human activities, indicating a consumption of hydrogen peroxide in the oxidation reaction with S(IV). The concentration of dissolved iron was observed to correlate with the percentage of S(IV), which may be an essential point for the reductive dissolution of oxidic iron compounds of the aerosol particles. As far as the speciation of the dissolved iron is concerned, it became obvious that the percentage of Fe(III) is anticorrelated to the concentration of dissolved iron. This clearly shows the important effect of the chemical and/or photo reductive ways of dissolving the iron(III)-compounds from the aerosol particles. However, a correlation between the pH-value and hydrogen peroxide was observed.  相似文献   

A large daylight geodesic dome for quantification of whole-ecosystem CO₂ and water vapour fluxes in arid shrublands     

John A. Arnone  III  Daniel Obrist 《Journal of Arid Environments》2003,55(4):629-643

We designed, constructed, calibrated and field-tested a lightweight (30 kg), 4.2 m diameter, 16.4 m³ polyethylene-covered dome static chamber ecosystem gas exchange cuvette that can quantify ecosystem CO₂ and water vapour fluxes as low as 0.1 μmol CO₂ m⁻² s⁻¹ and 0.1 mmol H₂O m⁻² s⁻¹ with little impact on environmental conditions. Fluxes measured in May 2001 in an intact Great Basin sagebrush ecosystem at midday were significantly higher than in an adjacent post-wildfire successional ecosystem, with observed ranges from –0.71 to 1.49 μmol CO₂ m⁻² s⁻¹ for CO₂ and from –0.09 to 0.53 mmol H₂O m⁻² s⁻¹ for water vapour.  相似文献   

Behavioural response of blackfly larvae (Simuliidae, Diptera) to different current velocities     

Ellen Kiel   《Limnologica》2001,31(3)

Video equipment was used to record and to compare the behaviour of different blackfly species at two flow velocities 0.25 m s⁻¹ and 1.35 m s⁻¹. Simulium noelleri Friederichs, Simulium ornatum (complex) Meigen and Simulium variegatum Meigen were studied. Effects of flow velocity on larval locomotive activties were analysed. Looping activity and the time needed to attach for filter feeding again were affectet to some extend, depending on species and flow velocity. While in S. ornatum no differences were recorded in locomotive activity, larvae of S. noelleri and S. variegatum were less active at high flow velocities. Larvae of S. noelleri also moved over shorter distances when exposed to high flow velocities. Consequences of the differences in behavioural response to flow velocities are discussed with respect to drift and silk pad adhesion.  相似文献