海藻酸裂解酶基因在毕赤酵母中的表达及重组酶性质的初步研究     

岳明  丁宏标  乔宇 《海洋学报》2007,29(5):154-160

褐球固氮菌(Azotobacter chroococcum)是一种海藻酸降解菌.本实验采用PCR的方法,以褐球固氮菌基因组DNA为模板,克隆出约1.05 kb的海藻酸裂解酶基因algL的成熟蛋白编码序列,并将其插入巴斯德毕赤酵母(Pichia pastoris)表达载体pPIC9K中,获得重组质粒pPIC9K-algL.重组质粒线性化后用聚乙二醇(PEG)法导入毕赤酵母菌株GS115中,获得高效分泌表达海藻酸裂解酶的毕赤酵母工程菌株.用甲醇诱导培养基进行摇瓶发酵,表达得到43 kDa的目的蛋白,酶活力可达1 400 U/cm3左右.经测定,该重组酶的最适反应pH为8.5,最适反应温度为40℃,并且在20~55℃,pH2.0~11.0具有较好的稳定性.另外,10 mmol/cm3的Cu2+,Fe2+,Co2+,Mn2+和Ca2+对酶有不同程度的抑制作用.  相似文献   

Reasons for Spatial Microdistributions of Foraminifers in an Intertidal Pool (Northern Adriatic Sea)     

Johann Hohenegger  Werner Piller  Christian Baal 《Marine Ecology》1989,10(1):43-78

Abstract. The spatial microdistribution of foraminifers was tested by the method of quadratic samplings on 2 sample grids in an intertidal pool of the northernmost Adriatic sea. Abundant species of foraminifers exhibit patchy distributions throughout; the distribution-patterns of some species correspond nearly completely. Using statistical methods (regression- and correlation-analyses) correlations to abiotic and biotic factors (water depth, exposure rate, seagrass, benthonic algae) were ascertained. The significant correlations of the foraminiferal frequencies to blue-green algae and/or diatoms enable an interpretation of these connexions as food dependences. Several foraminiferal species seem to have specific diets.  相似文献   

基于小型无人机可见光遥感的蓝藻识别研究   总被引：1，自引：0，他引：1  

李鑫  孙伟  李林 《测绘与空间地理信息》2017,(4)

以无人机航拍获取的可见光影像为数据源,研究小面积水域中蓝藻的提取方法。首先采用无人机获取可见光影像,运用4种可见光植被指数对图像进行运算,提出了用于蓝藻识别的可见光归一化差异植被指数与增强型红绿差值植被指数,以人工目视解译统计得到的蓝藻面积作为判别依据。结果表明:利用增强型红绿差值植被指数对湖泊中蓝藻的分类及提取,精度可达95.89%,Kappa系数为97.03,质量稳定,精度较高。  相似文献   

不同水动力下陆相碳酸钙沉积的蓝藻钙化试验的初步研究     

程星  石方红  李本刚  张金梅  潘响亮 《沉积学报》2012,30(6):1080-1087

 地表钙华,是喀斯特地区普遍存在的一种沉积体,是陆相碳酸钙沉积的重要类型。长期以来陆相碳酸钙沉积的水动力成因观点为大多数人所熟悉(1)（2）,生物成因观点则研究较少,在实际中生物作用过程也是不可忽略的,特别是藻类的沉积作用。论文以几种典型的蓝藻为例,通过对自然界水动力条件的模拟,对蓝藻藻类进行了几种水动力条件下的碳酸钙生物沉积试验研究,对比研究了在不同水动力条件下,蓝藻钙化沉积过程。试验得出了钙藻生长与钙化沉积的最适宜水动力为0~60 rpm,在过强的水动力条件下,蓝藻的生长将受到抑制,从而降低蓝藻的钙化沉积速率。文章讨论了在瀑布条件下的陆相碳酸钙沉积是以水动力成因为主导,而在水动力条件较弱的河流中以生物成因为主导,从而提出了,陆相碳酸钙沉积的水动力-生物双成因观点。文章还探讨了在静止状态下,藻类沉积对碳酸钙沉积的贡献大小,叠层石所指示的安静的沉积环境。   相似文献   

Isolation of plasmid from the blue-green algaSpirulina platensis     

Qin Song  Tong Shun  Zhang Peijun  C. K. Tseng 《中国海洋湖沼学报》1993,11(3):285-288

CCC plasmid was isolated from an economically important blue-green alga —Spirulina platensis (1.7×10⁶ dalton from the S₆ strain and 1.2×10⁶ dalton from the F₃ strain) using a rapid method based on ultrasonic disruption of algal cells and alkaline removal of chromosomal DNA. The difference in the molecular weight of the CCC DNAs from the two strains differing in form suggests that plasmid may be related with the differentiation of algal form. This modified method, which does not use any lysozyme, is a quick and effective method of plasmid isolation, especially for filamentous blue-green algae. Contribution No. 79 of the Experimental Marine Biology Laboratory and 2153 of the Institute of Oceanology, Academia Sinica. This research was supported in part by The President of the Chinese Academy of Sciences Foundation.  相似文献   

Discovery of branched tubular algae and microscopic tubes with annular-helical thickening from the Mesoproterozoic Ruyang Group of Shanxi,North China   总被引：2，自引：0，他引：2  

YIN Leiming  BIAN Lizeng & YUAN Xunlai . Nanjing Institute of Geology  Palaeontology  Chinese Academy of Sciences  Nanjing  China . Department of Earth Sciences  Nanjing University  Nanjing  China 《中国科学D辑(英文版)》2004,47(10):880-885

~~Discovery of branched tubular algae and microscopic tubes with annular-helical thickening from the Mesoproterozoic Ruyang Group of Shanxi, North China~~  相似文献   

The free jet as a means to improve water quality: Destratification and oxygen enrichment     

Jürgen Michele  Volker Michele 《Limnologica》2002,32(4):329-337

Rivers, lakes, and coastal waters are chaotic systems — physical, chemical, and biological parameters influence their development. Each parameter itself is influenced by the system. Human interaction has led to fast eutrophication. Oxygen input and artificial mixing have been considered as tools to overcome the biggest problems of fish kills, algal blooms, and bad odour. The favoured technology for destratification and oxygen input so far is the bubble curtain. This technology has been applied successfully in several cases. But often, this technology could not be implemented because of high investment and operating costs.

Alternatively, the free jet is discussed as an efficient and low investment and operating cost technology. The free jet may transport oxygen-rich water from the surface down into the hypolimnion, thereby destratifying a water system. A free jet entrains on its way down even more oxygen rich and warm epilimnic water. This water will finally — if some mixing with the cold hypolimnic water occurs — be transferred to the metalimnion. The density differences will make this water travel long distances.

The energy input may be very low and the objective must not be to totally overturn a system. A jet started in early spring may help a lake to have a deep enough epilimnion, relatively large in volume in respect to the hypolimnion, and the normal wind will recirculate the water transferring enough oxygen to the deeper part, thus expanding the fish habitat and enabling benthic fauna. Literature also shows that the occurrence of massive algal blooms may be reduced.

The oxygen efficiency can be multifold compared to standard technologies.  相似文献   

鱼腥藻对某些金属离子的吸附效应研究（Ⅱ）：鱼腥藻对金（Ⅲ）的吸附   总被引：6，自引：0，他引：6  

何金兰 《岩矿测试》1995,14(3):231-233

在ＰＨ５－７的缓冲介质中，鱼腥藻吸附Ａｕ＾３＋，然后用６ｍｏｌ／ＬＨＣｌ洗脱，回收率在９８％－１００％。在选定条件下，鱼腹藻对Ａｕ＾３＋的最大吸附量为１５．７－１８．８ｍｇ／ｇ。所拟方法可供低含量Ａｕ＾３＋溶液中Ａｕ＾３＋的富集。  相似文献   

Microfossils and molecular records in oil shales of the Songliao Basin and implications for paleo-depositional environment   总被引：1，自引：0，他引：1  

ZiHui Feng  Wei Fang  Xue Wang  ChunYan Huang  QiuLi Huo  JuHe Zhang  QingHua Huang  Lei Zhang 《中国科学D辑(英文版)》2009,52(10):1559-1571

Several oil shale beds, over 10 m thick, occur at the base of the first member of the Upper Cretaceous Qingshankou Formation (K2qn1) in the Songliao Basin. They act both as excellent source rocks for conventional oil and as potential oil deposit for shale oil production. Here we combine micropaleon-tology with organic geochemistry to investigate the paleo-depositional environment and organic source characteristics of the oil shales and black shales. Our results indicate that algal remains are dominant micro...  相似文献   

巢湖、太湖蓝藻湖靛及其提取物的动物毒性初步研究   总被引：1，自引：0，他引：1  

瞿文川  苏晨伟 《湖泊科学》1996,8(2):156-160

对国内淡水湖泊巢湖、太湖中的蓝藻湖靛及其提取物（藻胆蛋白）,进行了动物毒性实验。实验动物为昆明种小白鼠,采用灌胃法给药。给药后小白鼠均无中毒症状,一周内无死亡。说明巢湖、太湖中蓝藻湖靛及其提取物,对以小白鼠为代表的哺乳类动物消化系统,基本不产生毒性。这对于开发两湖中的蓝藻作为鱼、家禽等饲料和提取其中的植物蛋白（藻胆蛋白）作为营养食品添加剂等有一定意义。  相似文献