锰对盐藻生长与物质积累的调控作用   总被引：1，自引：0，他引：1  

郭金耀  杨晓玲 《水产科学》2008,27(3):148-150

试验结果表明,培养液中锰质量浓度过高或过低都不利于盐藻细胞的生长与物质积累。培养基中锰质量浓度为4.0 mg/L时,盐藻细胞生长、蛋白质合成与β-胡萝卜素积累最多。当培养液中锰质量浓度较高(8.0 mg/L)或较低(2.0 mg/L)时,单个盐藻细胞中的蛋白质与β-胡萝卜素含量较高。但此时,因培养液中细胞密度较低,盐藻细胞积累的物质总量仍然较少。在锰质量浓度较高或较低的逆境条件下,盐藻可能通过适应性反应形成了逆境蛋白质与胡萝卜素等。  相似文献   

稚鱼生物饵料的DHA营养强化   总被引：8，自引：0，他引：8  

张利民 《齐鲁渔业》1996,13(5):36-38

综述了国内外海水稚鱼生物饵的ＤＨＡ营养强化技术研究及其应用状况，轮虫、卤虫的营养强化方法和注意事项。  相似文献   

杜氏藻对盐度的生理反应   总被引：2，自引：0，他引：2  

马志珍  武振彬 《海洋水产研究》1992,(13):103-115

1987年从天津汉沽盐场盐池分离培养了数个杜氏藻品系。1989年对其中盐生杜氏藻878和绿色杜氏藻876进行了盐度(分波美度3°、5°、10°、15°和20°5组)试验,试验水温为25±1℃,光照强度约40001x,光照时间10:14(L:D),N∶P∶Fe=20∶2∶1ppm。结果为最大生长量和最大生长率在波美度10°组。盐生杜氏藻878在波美度3°下,藻细胞呈绿黄色,5°和10°下为绿色,15°下为桔黄色,20°下为桔红色。绿色杜氏藻876,在所有的试验盐度下均为绿色。两个品系的细胞大小均随盐度增加而变小。从高盐度(20°Be′)接种到低盐度(3°Be′)适应较快。从低盐度(2.5°Be′)到高盐度(15°Be′)适应较慢。  相似文献   

杜氏盐藻基因DsSP的克隆、分析和原核表达(英文)     

刘世才  柴晓杰  郭卫华  王逸玉  韩冬梅 《农业科学与技术》2014,(6):907-915

[目的]克隆盐藻淀粉磷酸化酶基因,并初步分析其基本性质和表达蛋白。[方法]采用RT-PCR和RACE的方法克隆基因;生物信息学系统分析其性质;构建原核表达载PGS21a-DsSP转化于E.coli BL21表达蛋白,采用GST-SefinoseTMKit和Western Blot分别纯化、检测该融合蛋白。[结果]成功克隆出1种淀粉磷酸化酶(GenBank accession No.KF061044)命名为DsSP;分析得到了其基本性质并预测了该蛋白的亚细胞定位、二级结构和三级结构;该融合蛋白在上清和包涵体中均存在,且对上清蛋白成功纯化;Western Blot检测表明其在E.coli.BL21中成功表达。[结论]为进一步阐明DsSP的功能及作用机制奠定了理论基础。  相似文献   

杜氏盐藻和亚心型扁藻混合培养生长的初步研究   总被引：3，自引：0，他引：3  

蔡卓平  段舜山 《水产科学》2008,27(7)

在实验室条件下研究了杜氏盐藻和亚心型扁藻在单独培养和相同接种比例混合培养下的生长情况。结果显示,单独培养盐藻的生长经历了3个明显的阶段,生长曲线呈现"S"型;单独培养扁藻与混合培养藻在18 d内还未到达稳定期,仍保持一定的生长态势。混合培养、单独培养盐藻以及单独培养扁藻的最大光密度值(OD680)分别为0.784、0.702和0.765。混合培养藻的生物量(0.841 mg/ml)也稍高于单独培养盐藻(0.582 mg/ml)和单独培养扁藻的生物量(0.819 mg/ml)。试验结果表明,混合培养盐藻和扁藻具有一定的促进藻生长和提高生物量产出的潜力。  相似文献   

Effects of Iron Deficiency on Thylakoid Membrane Structure and Composition in the Alga Dunaliella salina     

《Journal of plant nutrition》2013,36(10-11):2197-2210

Abstract

The unicellular green alga Dunaliella was previously proposed as a model photosynthetic organism for adaptation to iron deficiency. The purpose of this study was to find out how iron limitation affects the structure and composition of the photosynthetic system of Dunaliella salina. Iron deprivation did not retard proliferation of D. salina cells, but was associated with a decrease in cell volume and chlorophyll content, and with a four‐fold reduction in iron content and a two‐fold increase in Cu content. Electron microscopic analysis revealed shrinkage of the chloroplast and decrease in stacked thylakoid membranes. Measurements of chlorophyll fluorescence induction in the presence of DCMU and of 77 K chlorophyll fluorescence emission spectra indicated gross changes in the photosynthetic efficiency of reaction centers and in the organization of their associated light harvesting antenna. Differential analysis of protein composition led to the identification of a major thylakoid membrane protein (Tidi), that was specifically induced under iron deprivation. Partial sequencing suggests that Tidi is a novel type of a chlorophyll a/b binding protein. These results clearly show that iron limitation is associated with extensive reorganization of the photosynthetic system in Dunaliella.  相似文献   

滩涂盐碱土壤微生物生态特征的研究     

康贻军　胡健董必慧  陆小云 《农业环境科学学报》2007,26(B03):181-183

采集江苏省滨海县滩涂盐碱地土壤,以菜园土壤作为对照,系统研究了微生物区系及生态、生理特征.结果表明,盐碱土壤微生物区系和对照相比发生了重大变化,除细菌数量与对照无显著差异外,真菌、放线菌、解磷菌及钾细菌数量分别比对照土壤低1.57倍、22.34倍、5.59倍及259.39倍,达极显著差异;盐碱土基础呼吸作用、微生物生物量碳分别比对照低1.01倍(达极显著差异)、0.94倍(达显著差异),但基础代谢商(qCO2)却和对照无显著差异;盐碱土过氧化氢酶活性比对照低1.19倍,而脲酶活性却比对照高0.41倍,均达极显著差异.  相似文献   

盐度对绿色杜氏藻生长速率、叶绿素含量及细胞周期的影响   总被引：4，自引：1，他引：4  

刘青  苏绣榕  李太武  杨凤香 《大连水产学院学报》2003,18(2):90-94

在不同盐度梯度下,进行了盐度对绿色杜氏藻Dunaliellaviridis的生长、叶绿素含量和细胞周期影响的试验。结果表明:1)绿色杜氏藻在盐度为10时,生长速率和单位水体叶绿素含量最低,分别为0 121个/d和908 27μg/L;在盐度为60时,生长速率和单位水体叶绿素含量最高,分别为0 381个/d和1192 41μg/L。2)不同盐度下单位细胞叶绿素含量呈现高-低-高的变化趋势,盐度60时,单位细胞叶绿素含量最低,叶绿素a为2 32×10-6μg/个,叶绿素总量为3 31×10-6μg/个。3)盐度为60时,绿色杜氏藻的细胞周期S期最短,为36 9%,G2期为0 8%;盐度80时,绿色杜氏藻的G2期最短,为0 3%,S期为43 6%,即绿色杜氏藻在盐度为60～80时,S期、G2期最短,细胞进入分裂期所用时间最短。本试验结果表明,培养绿色杜氏藻以盐度60～80的水体最为适宜。  相似文献   

Ecotoxicological evaluation of Harbour sediments using marine organisms from different trophic levels     

Luigi Pane  Elisabetta Giacco  Christian Corrà  Giuliano Greco  Gian Luigi Mariottini  Franco Varisco  Marco Faimali 《Journal of Soils and Sediments》2008,8(2):74-79

Background, Aim and Scope  The toxicity of contaminated sediments should be evaluated considering the direct exposure of laboratory organisms to whole sediments and the indirect exposure to elutriates or extracts (Tay et al. 1992, Byrne and Halloran 1999, Nendza 2002). The alga Dunaliella tertiolecta is indicated for the use in toxicity bioassays because it is highly sensitive to several xenobiotics. Harpacticoid copepods have been already used for toxicity testing and Tigriopus fulvus is a promising Mediterranean target-species in ecotoxicology (Todaro et al. 2001, Faraponova et al. 2003, Pane et al. 2005a). In this study, the toxicity of sediments collected in harbour sites of the Northeastern Adriatic Sea was evaluated by growth inhibition test with free living and alginate-immobilized Dunaliella tertiolecta and acute toxicity test with nauplii and adult Tigriopus fulvus with the aim of pointing out the importance to utilize model organisms from different trophic levels in sediment ecotoxicology. Methodology  Elutriates and whole sediments were tested on free living and immobilized (Pane et al. 1998) algal cells, and on laboratory reared copepods. Free-living D. tertiolecta were exposed to diluted elutriates in a static, multi-well plate system. Naalginate immobilized D. tertiolecta were placed in polystyrene inserts fitted with polyester mesh bottoms and exposed to a thin layer (2 mm) of whole sediments in multi-well plates (EPS 1992, Pane and Bertino 1999). Toxicity tests with copepods were carried out on Tigriopus fulvus nauplii (elutriates) and adults (whole sediments and elutriates). Same-aged nauplii useful for toxicity tests were obtained by egg sac detaching and consequent hatching stimulation (Pane et al. 2006). Newborn nauplii (I–II stage) were exposed to elutriates in multi-well plates provided with polystyrene inserts. Adult T. fulvus maintained in polystyrene inserts fitted with polyester mesh bottoms were placed in contact with a thin layer (2 mm) of whole sediment placed on multi-well plate bottoms. All end-points were evaluated after 96 h. Results  In general, the effects increased with the increasing of elutriate concentration up to 50%; the stimulation or inhibition of algal growth was statistically significant in comparison to the control. The inhibiting elutriates induced EC₅₀ variations of algal growth ranging from 66.9% to 74.3%. The mortality of T. fulvus nauplii was always < 25% after treatment with 100% elutriates and < 10% after treatment with 50% dilution; no effect was shown up with 25% dilution; therefore LC₅₀ was not calculable. The effect of elutriates was negligible on adult copepods and LC₅₀ values were never calculable; percent mortality always resulted in < 10% after treatment with whole sediments. Discussion  Both experimental systems gave substantially similar results after exposition to whole sediments and elutriates. During the experiment with algal cells, the immobilization in Na-alginate and the employment of inserts which allowed the contact of organisms with sediments and their easy counting were particularly useful. Likewise, the employment of inserts of adequate mesh size in the tests with copepods allowed the contact of organisms with the sediment and made organism handling and counting easy, as well as the evaluation of mortality. The methodology here described and the utilization of the proposed test-species could have an importance also considering that the current trend in ecotoxicological research is towards finding the most appropriate organism for specific areas of concern by using indigenous species (Mariani et al. 2006) and towards the major significance of chronic and reproductive end-points. Conclusions  Based on the above results, it can be stated that the bioassay with Dunaliella tertiolecta could be a good estimation tool for the ecotoxicological assessment of marine sediments. The immobilization of algae in Na-alginate was seen to be useful to evaluate the toxicity of whole sediments; the employment of polystyrene inserts allowed an improvement of the procedures. T. fulvus nauplii and adults, as other harpacticoids such as Tigriopus japonicus (Yoon et al. 2006), satisfy the basic criteria for the employment of a standard species in marine bioassays. To date only pelagic Acartia tonsa are utilized in the standardized procedure to evaluate the risk assessment of chemicals or wastewaters (ISO 1999). As, on the contrary, the exposure of copepods to solid-phase contaminants it is not yet standardized, the employment of polystyrene inserts improved the procedures for T. fulvus too. So, the rapidity and the possibility to solve practical problems could be the main attractive features of this technique (Pane et al. 2005a) when applied to whole sediments. Recommendations and Perspectives  The methodology here developed being also applicable to long term and reproduction tests should be recommended because it provides relevant information in comparison with other frequently applied, standardized biotests with crustaceans (ISO 1999). The procedure has been shown to be easily applicable to selected marine organisms. ESS-Submission Editor: Prof. Dr. Henner Hollert (henner.hollert@bio5.rwth-aachen.de)  相似文献   

杜氏盐藻MAPKK激酶基因DsMAPKKK的克隆、原核表达与纯化     

柴晓杰  刘艺琼  王逸云  武天祥  刘丽颖 《中国农学通报》2015,31(23):53-57

为了进一步研究MAPKK激酶的生理功能,利用RT-PCR技术扩增了DsMAPKKK的开放阅读框序列,并利用T4连接酶与质粒pGS21a连接,构建了原核表达载体pGS21a-DsMAPKKK。将该重组质粒导入大肠杆菌BL21(DE3)感受态细胞,经IPTG诱导成功表达了融合蛋白。经SDS-PAGE检测,融合蛋白在上清和包涵体中均存在。可溶性蛋白经过GST柱纯化,电泳分析结果表明,在68kD左右有单一的蛋白条带,说明融合蛋白得到有效纯化。蛋白印迹结果显示在68kD左右有明显的杂交条带,初步证明纯化的蛋白就是带有GST标签的MAPKK激酶。DsMAPKKK的成功表达与纯化,为深入探讨DsMAPKK激酶的性质及功能打下了坚实的基础。  相似文献