褐藻酸降解菌在海带绿烂病发生中的作用   总被引：1，自引：1，他引：1  

王丽丽  唐学玺  王蒙  张培玉 《中国海洋大学学报(自然科学版)》2003,33(2):245-248

从海带幼苗上病烂明显处分离得到 2 3株褐藻酸降解菌 ,并对其菌落形态、细胞形态及革兰氏染色反应等进行了观察。通过对褐藻酸钠的降解实验 ,筛选出 4株具较高降解能力的菌株。感染实验表明 ,分离到的褐藻酸降解菌为海带幼苗病烂的主要病原菌。  相似文献   

Allelopathic growth inhibition of Heterosigma akashiwo by the three Ulva spcieces (Ulva Pertusa, Ulva Linza, Enteromorpha intestinalis) under laboratory conditions     

WANG Renjun  FENG Lei  TANG Xuexi  WANG Jinhe  DONG Shuanglin 《海洋学报(英文版)》2012,31(3):138-144

Allelopathic effects of several concentrations of fresh tissue,dry powder and dry tissue of three bloom-forming green macroalgae Ulva pertusa,Ulva linza and Enteromopha intestinalis on the red tide microalga Heterosigma akashiwo were evaluated in microcosms systems.The effects of macroalgae culture medium filtrate were investigated on H.akashiwo using initial or semi-continuous filtrate addition.Preliminary studies on the algicidal effects of one aqueous and four organic solvent extracts from the macroalgae on the microalga were carried out to confirm the existence of allelochemicals in the tissue of these macroalgae.The dry powder of U.pertusa was extracted with methanol,and the methanol extracts were partitioned to petroleum ether phase,ethyl acetate phase,butanol phase and distilled phase by liquid-liquid fractionation.The bioassays of the activity of every fraction were carried out on H.akashiwo.The resultant microcosms assay showed that the growth of H.akashiwo was strongly inhibited by using fresh tissues,dry powder or dry tissue of these three macroalgae,while aqueous and methanol extracts of both macroalgae had strong inhibitory effects on the growth of H.akashiwo,and the EC 50 values for methanol extract of U.pertusa,U.linza or E.intestinalis were 0.016,0.028×10-12 or 0.033×10-12,respectively.While the other three organic solvent extracts（acetone,ether and chloroform） had no apparent effect on its growth,this suggests that the allelochemicals from these three macroalgae had relatively high polarities.The activity of petroleum ether phase,ethyl acetate phase,butanol phase and distilled phase of U.pertusa methanol extract was carried out on H.akashiwo indicating that petroleum ether phase and ethyl acetate phase had stronger algicidal effect on H.akashiwo.The inhibition effect of the ethyl acetate phase was not as strong as that of petroleum ether phase,and effective concentration of petroleum ether phase was 17 mg/L for H.akashiwo.However,no significant algicidal effects were observed on the butanol phase and distilled water phase.These three macroalgae＇s culture medium filtrate exhibited no apparent growth inhibitory effect on the microalga under initial filtrate addition whereas the growth of H.akashiwo was significantly inhibited under semi-continuous filtrate addition,which suggests that continuous release of small quantities of rapidly degradable allelochemicals from the fresh tissue of both macroalgae was effective in inhibiting the growth of H.akashiwo.  相似文献   

Diversity and Bioactivity of Actinomycetes from Marine Sediments of the Yellow Sea     

ZHANG Shumin  YE Liang  TANG Xuexi 《青岛海洋大学学报(英文版)》2012,(1):59-64

  相似文献   

Effect of CO2 enrichment on competition between Skeletonema costatum and Heterosigma akashiwo     

徐达  周斌  王悠  鞠青  于庆云  唐学玺 《中国海洋湖沼学报》2010,28(4):933-939

We investigated the effect of CO₂ enrichment and initial inoculum density on competition between Skeletonema costatum and Heterosigma akashiwo, two common algae seen in algal blooms. The initial inoculum density (0.2×10⁴, 0.4×10⁴, 0.8×10⁴ cells/ml) had a significant effect on population growth and competition between H. akashiwo and S. costatum. The time required for population growth to reach the exponential growth phase and stationary phase decreased significantly as the initial density increased. When the two species were cultured together, S. costatum tended to outcompete H. akashiwo, especially when present at higher initial ratios. CO₂ enrichment (5 000 μl/L CO₂) increased the maximum population density and carrying capacity of H. akashiwo but decreased these measures for S. costatum. Thus, CO₂ enrichment favored the growth of H. akashiwo over S. costatum.  相似文献   

砾石级沙粒胶结体抗风蚀效益的实验研究   总被引：1，自引：1，他引：0  

孙娜  李生宇  马学喜  王海峰  徐新文 《中国沙漠》2016,36(3):575-580

塔克拉玛干沙漠腹地部分垄间地表发育了一种由众多沙粒胶结而成的大颗粒物质,称为沙粒胶结体(sand cemented bodies,缩写为SCB),其直径达到粗沙级、极粗沙级和砾石级。为了研究其对地表风沙活动的影响,本研究以野外采集的砾石级沙粒胶结体(gravel-size sand cemented bodies,缩写为GSSCB)为实验材料,在净风和挟沙风条件下进行了GSSCB覆盖沙面的抗风蚀模拟实验。结果表明:床面的蚀积状态与来流条件、GSSCB覆盖度和风速均有关,净风时所有覆盖度床面均呈风蚀状态,挟沙风时随覆盖度和风速而变化,床面可呈3种状态-风蚀、蚀积平衡、风积;在风蚀状态时,床面风蚀率随覆盖度增大以指数形式降低,随风速增大而以多种函数形式增加,抗风蚀效率随覆盖度增大而逐渐增加,但不同覆盖度范围增加率不同;挟沙风条件下呈蚀积平衡状态时的床面覆盖度临界C_b值与风速大小有关,随风速增加呈幂函数形式增加;在挟沙风条件下,覆盖度大于C_b值时床面呈风积状态,积沙率与风速的关系较为复杂,80%覆盖度床面积沙率随风速增大呈对数形式增加,但40%覆盖度床面积沙率则随风速增加呈指数形式降低。可见,由于与砾石的物理性质相近,GSSCB覆盖确实具有与砾石相类似的抗风蚀效益,并且在一定覆盖度条件下还能捕获风沙流挟沙颗粒。因此,塔克拉玛干沙漠腹地丘间地天然发育的GSSCB对于地表蚀积过程具有重要影响。GSSCB可作为一种新型固沙技术进行开发。  相似文献   

塔克拉玛干沙漠腹地垄间沙粒胶结体的基本特性及研究价值   总被引：1，自引：1，他引：0  

李生宇  孙娜  马学喜  徐新文 《中国沙漠》2016,36(2):265-273

在塔克拉玛干沙漠腹地的部分垄间平沙地中,天然分布有一种特殊物质——沙粒胶结体,其与地表的粗沙和极粗沙呈复区分布,共同构成了覆盖沙面的大颗粒层。实地调查和取样分析表明:沙粒胶结体直径不一,能达到粗沙级、极粗沙级和砾石级(细粒和中砾),最大可达23.5 mm;颗粒形状不规则,质地较硬,手捏不碎;密度为2.51 g·cm^-3,略小于砾石和当地沙丘沙;可溶物的pH值呈中性,电导率2.56 mS·cm^-1,主要成分为CaSO₄。砾石尺度的沙粒胶结体在地表的分布密度可达807粒·m^-2,覆盖度2%~3%,由于其尺度和密度与砾石接近,它也应具有与砾石类似的风沙效应。沙粒胶结体也是一种天然固沙材料,研究其形成机制有助于开发新型固沙技术和固沙产品;沙粒胶结体可以抑制沙面风蚀、调节风沙流输沙强度、影响沙丘形态演变,探讨其风沙效应有助于深入认识塔克拉玛干沙漠垄间地的沙面稳定机制。沙粒胶结体的形成应与特殊的地质历史环境背景有关,可以作为沙漠地区历史时期气候变化的一个证据。因此,沙粒胶结体在防沙治沙技术开发、沙漠地区特殊下垫面风沙运动过程、沙漠环境形成演变等方面具有重要的研究价值,值得今后进行深入研究。  相似文献   

Response of marine microalgae,heterotrophic bacteria and their relationship to enhanced UV-B radiation   总被引：1，自引：0，他引：1  

ZHOU Wenli）  ）  TANG Xuexi）  *  XIAO Hui）  WANG You）    WANG Renjun）  ）） College of Marine Life Sciences  Ocean University of China  Qingdao  P. R. China ） Tianjin Key Laboratory of Aqua-ecology  Aquaculture  Tianjin Agricultural University  Tianjin  P. R. China ） College of Life Science  Qufu Normal University  Qufu  P. R. China 《中国海洋大学学报(英文版)》2009,8(1):35-38

Ozone depletion in the stratosphere has enhanced solar UV-B radiation reaching the Earth surface and has brought about significant effects to marine ecosystems. The effects of enhanced UV-B radiation on marine microalgae, heterotrophic bacteria and the interaction between them are discussed. The effects on marine microalgae have been proved to occur at molecular, cellular and population levels. Enhanced UV-B radiation increases microalgal flavonoid content but decreases their chlorophyll content and pho-tosynthesis rate; this rachation induces genetic change and results in DNA damage and change of protein content. There have been fewer studies on the effects of UV-B radiation on marine heterotrophic bacteria. Establishment of a nucroalgal ecological dynamic model at population and community levels under UV-B radiation has gradually become a hotspot. The effects of enhanced UV-B radiation on microalgae communities, heterotrophic bacterial populations and interaction between them will become a focus in the near future. This paper will make an overview on the studies concerning the effects of enhanced UV-B radiation on marine microal-gae and heterotrophic bacteria and the interaction between them.  相似文献   

海带多酚的产生与抗褐藻酸降解菌感染的相关性   总被引：1，自引：0，他引：1  

李春雷  唐学玺  张培玉  王丽丽 《中国海洋大学学报(自然科学版)》2003,33(6):925-929

利用生物化学的方法探讨了褐藻酸降解菌感染过程中海带体内多酚含量的变化 ,并分析了多酚含量的高低与海带对褐藻酸降解菌感染抗性的相关性。研究结果表明 :褐藻酸降解菌感染下海带体内多酚含量急剧上升 ,并且这种变化具有普遍性 ;多酚含量的急剧上升只发生在褐藻酸降解菌感染的初期阶段 ;海带体内多酚含量的高低与海带对褐藻酸降解菌的抗性具有明显的相关性。表明多酚类化合物在海带抵抗褐藻酸降解菌的感染中起重要作用  相似文献   

蒽对扁藻和盐藻的毒性效应   总被引：6，自引：1，他引：6  

王悠  唐学玺  杨震  李永琪 《海洋通报》1999,18(6):84-86

多环芳烃蒽对盐菏和扁藻的生长具有抑制交蒽对２对海洋微藻的７２ｈ半抑制剂量分别为３０．２μｇ／Ｌ和１７．２μｇ／Ｌ,说明扁藻对蒽的毒性胁迫表现更为敏感。对２种藻细胞超氧化物歧化酶活性的研究表明,盐藻ＳＯＤ活性明显高于扁藻的ＳＯＤ活性,且在蒽的胁迫过程中下降幅度也较小。  相似文献   

多溴联苯醚在海洋环境中的分布及其对海洋生物的影响研究   总被引：4，自引：0，他引：4  

唐学玺  柯可  王悠 《海洋湖沼通报》2010,(1)

持久性有机污染物多溴联苯醚(PBDEs)具有持久性、高生物蓄积性和高生物毒性等特征,它在海洋中广泛存在并呈现出浓度不断增加的趋势,对海洋生物的潜在威胁受到广泛关注。本文综述了PBDEs的来源、特性及其在海洋环境中的含量分布和对海洋生物的危害,并对可能的作用机理进行了探讨。同时,对PBDEs在海洋环境中的研究重点和趋势进行了展望。  相似文献