Progress in phototaxis mechanism research and micromanipulation techniques of algae cells

Phototactic movement is a characteristic of some microorganisms' response to light environment. Most of the algae have dramatically phototactic responses, underlying the complicated biological, physical and photochemical mechanisms are involved. With the development of the micro/nano and sensor techniques, great progress has been made in the research of the algae phototaxis. This review article summarizes the progress made in the research on the functional phototactic structures, the mechanisms of photo-response process and photodynamics of phototaxis in algae, and describes the latest developed micro-tracking technique and micromanipulation technique. Moreover, based on our own research results, the potential correlation between the phototaxis and photosynthesis is discussed, and the directions for future research of the phototactic mechanism are proposed.     

Progress in phototaxis mechanism research and micromanipulation techniques of algae cells

Phototactic movement is a characteristic of some microorganisms' response to light environment. Most of the algae have dramatically phototactic responses, underlying the complicated biological, physical and photochemical mechanisms are involved. With the development of the micro/nano and sensor techniques, great progress has been made in the research of the algae phototaxis. This review article summarizes the progress made in the research on the functional phototactic structures, the mechanisms of photo-response process and photodynamics of phototaxis in algae, and describes the latest developed micro-tracking technique and micromanipulation technique. Moreover, based on our own research results, the potential correlation between the phototaxis and photosynthesis is discussed, and the directions for future research of the phototactic mechanism are proposed.     

Characteristic and mechanism of inactivating algae with O3 and ClO2

Both O3 and ClO2 have a high effect on inactivating-algae in source water with no forming THMs which do harm to human in producing drinking water, so they will be favorably substituted for Cl2. In order to make certain of the mechanism of inactivating algae with O3 and ClO2, the algal cell number change and its different characteristics of figures and structures in treated and untreated water have been studied by the microscopy and SEM and the mode of inactivating algae has been inferred. The results show that the mechanism of inactivating algae by O3 is not completely identical with that by ClO2. The actual reaction process and efficiency have been controlled by many factors, such as the different characteristics of oxidants and algal cells.     

富营养化水源水中藻类控制的研究进展

综述了水源水体中种藻类控制技术的现状,概要地介绍了应用于富营养化水体中藻类控制的物理,化学,生理技术机理与伴生的问题,指出将各种方法有机结合,研究开发生物生态工程技术,高效的湖内控制策略,各部门管理密切配合是以后可能的发展方向。     

4种淡水藻对硝基苯的抗性机制

选择了4种淡水藻——纤细裸藻、莱因衣藻、舟形藻和聚球藻,通过分析硝基苯对其生长和叶绿素含量的影响,以及藻细胞对硝基苯的降解、积累和抗氧化酶系统的响应,以期了解藻类对硝基苯的抗性机制．结果表明：4种藻的生长和叶绿素a含量对硝基苯的抗性,按抗性大小排列：纤细裸藻〉莱因衣藻〉舟形藻〉聚球藻,4种藻对硝基苯无显著的降解和积累能力,藻细胞对硝基苯的抗性主要依赖抗氧化酶系的防御作用,其中藻细胞的SOD起主要作用,POD起次要作用．     

荒漠地区土壤表层固碳作用研究进展

 干旱、半干旱地区的生态环境条件脆弱,光能自养生物在荒漠地区地表的物质循环和能量流动中起着重要作用。藻类和苔藓是荒漠地区地表普遍存在的固碳生物,不仅能够改善土壤的物理性质,起到保护土壤的作用,同时能够通过特定蓝藻的固氮作用增加土壤的氮含量,最重要的是这些固碳生物能够通过光合作用固定空气中的CO₂,是荒漠地区土壤表层固碳的主要贡献者。荒漠地区生态系统固碳量的研究也是研究全球气候变化的重要组成部分,固碳量的大小不仅受自然条件的约束,也与土壤表层固碳生物（主要是藻类和苔藓）的组成密切相关。当土壤中仅有丝状蓝藻存在时固碳速率较低,随着绿藻等高等藻类和苔藓的出现,固碳速率快速增加。本文综述了荒漠地区土壤表层固碳生物组成和影响地表固碳的因素,回顾和展望了地表固碳的研究方法。     

哺乳动物克隆的研究进展

哺乳动物体细胞克隆是20世纪末生命科学领域最引人注目的高新技术,该技术在农业、生物学和医药等方面具有广泛的应用前景。近年来克隆技术发展迅速,多种哺乳动物相继克隆成功,但也存在着克隆效率太低、克隆动物表型正常而实质异常等问题。本文在近年来克隆技术研究的基础上,对克隆的概念、研究历史以及克隆的方法、过程进行了综述,展望了克隆的意义及克隆动物的应用前景,分析了目前克隆技术尚存在的问题,并提出了解决这些问题的关键。     

Cu-FeOx@AC活化PMS体系除藻效能与机制

为探究富营养化水体中藻类的新型治理技术，通过水热法和高温煅烧法，使颗粒活性炭（AC）表层上负载铜铁双金属氧化物Cu-FeO_x，制得可回收的Cu-FeO_x@AC复合催化剂。以XRD、SEM、FTIR和XPS对Cu-FeO_x@AC的表征为基础，研究Cu-FeO_x占AC的负载比、过一硫酸盐（PMS）使用量、初始pH及不同反应体系对除藻的影响，探究Cu-FeO_x@AC活化过一硫酸盐体系的除藻效能。Cu-FeO_x@AC活化过一硫酸盐体系反应机理，通过自由基淬灭实验、XPS表征进行探究。结果可知，初始pH为6，初始藻细胞密度为1.4×10⁹个/L，使用催化剂0.5 g/L，PMS 0.2 g/L时，反应90 min，该体系对藻的降解率有97.25%。在该体系中，藻细胞能被吸附在Cu-FeO_x@AC复合催化剂表面，在铜、铁不同价态离子的转换及AC的协同作用下，产生空穴、·O2-、·OH、SO4-·，单线态氧等多种氧化基团而被去除。     

海藻对废水中重金属吸附的研究进展

海藻具有特殊的细胞壁结构,其化学改性后具有较高的重金属富集吸附能力。化学改性后的海藻具有吸附量大,吸附速率快以及简易的解吸附等优点,被认为是理想的生物吸附材料。本文描述了海藻吸附剂对重金属的吸附作用,分析了温度、pH值、光照对其吸附效率的影响并剖析了吸附机理,最后对海藻吸附剂在改性方面研究的进展情况和其未来的发展趋势进行了展望。     

贵州百里杜鹃国家森林公园藻类植物初步调查

通过对贵州百里杜鹃林2007年5月的藻类植物初步鉴定,共检出藻类植物61种(含变种及变型),分属4门,6纲,14目,24科,34属。其中蓝藻有30种,占总种数的44.12%,其次是硅藻,有22种占36.07%,表明百里杜鹃林藻类植物以蓝藻和硅藻的种类居多;水生环境中的种类以硅藻占多数,亚气生环境中以蓝藻种类占多数。但在树皮上形成优势种常为绿藻中的土生绿球藻。土生绿球藻、小球藻、颗粒粘球藻、铜绿粘球藻、瑞士色球藻等是构成地衣的常见种类。     

高效液相色谱-电感耦合等离子体质谱检测海藻中的砷

以阴、阳离子交换色谱与电感耦合等离子体质谱联用检测砷的形态,测定了我国不同海域海藻(海带、紫菜)10种样品中的砷.样品总砷的浓度为1.7~38.7mg/kg As(干重).所有样品萃取物中,砷糖为砷的主要形态,在大多数紫菜样品中砷糖PO4为主要化合物0.4~12.7 mg/kg As(干重),其次为砷糖OH 1.0~7.8 mg/kg As(干重).海带样品除含有以上两种砷糖外,还含有砷糖SO3(8.9~17.6 mg/kg As干重),及DMA(1.7~3.2 mg/Kg As干重),无机砷在所有样品萃取物中未检出.     

润湿反转机理的研究进展

介绍了近年来国外针对润湿反转作用提高采收率的研究进展.首先介绍了一种测定润湿角的方法——双滴双晶法(DDDC).对比了近几年国外常用的几种润湿反转剂.研究表明:阳离子、阴离子以及非离子表面活性剂在有效作用浓度以及作用机理上存在明显区别.综合各种试验结果,认为含有聚氧乙烯(丙烯)基的阴离子或是非离子活性剂具有较好的应用前景.最后通过分析固体表面润湿反转导致的油珠剥离过程,以及不同阶段的力学变化规律,发现润湿反转作用主要受到固液界面张力的影响,而油水界面张力并不是决定性的影响因素.因此,有必要进一步研究表面活性剂对固液界面张力的影响规律.     

富营养化湖泊中藻类蛋白特征及其资源化开发

藻类的大量繁殖是富营养化水体最显著的污染特征.介绍我国富营养化水体中藻类生长特性、营养价值,就藻类蛋白在食品、药品、光电材料、生物探针、环境监测、毒素等方面的资源化开发利用进行了综述,相关研究成果对富营养化水体中藻类蛋白的资源化开发利用具有重要的意义.     

2种海藻对氮磷移除效果及其生长特征研究

以三亚地区海水养殖场水体中的氮磷质量浓度ρ幅度为依据,分别构建秋季最高(26℃)与最低温度(22℃)下的氮磷质量浓度ρ梯度,以羽毛藻和齿形藻为研究对象,测定了2种海藻生长过程中降解和吸收人工海水中氮磷营养盐的能力;同时依据不同营养盐水平下2种藻类的光合作用强度对其生长特征进行了分析.结果表明:1)羽毛藻和齿形藻对三亚海水养殖场的氮、磷有很好的去除效果;磷的去除率随介质ρ(磷)的提高而提高,最高可达35%~40%;氮的最高去除率为26%~32%,随介质中ρ(氮)的增加呈下降趋势.2)ρ(氮)、ρ(磷)波动范围内基本不会对2种藻类生长产生明显的不利影响,但温度22℃、ρ(氮)150mg·L~(-1)的条件对齿形藻的光合作用和代谢作用可产生严重的不利影响.氮、磷营养盐质量浓度对这2种大型海藻在营养盐吸收和光合作用等方面有一定的生理影响,因此将这2种大型经济海藻大规模养殖进行原位生态修复富营养化海水时,应注意环境因子对其的影响.该研究可为这2种海藻的大规模养殖修复富营养化海水提供一定的理论支持.     

褐藻及褐藻酸的研究现状和进展

褐藻及从褐藻中分离出的一种重要化合物——褐藻酸具有广泛的应用价值。对褐藻的生物性状、地域分布及其产品褐藻酸的种类、地域分布、化学结构、理化性质、生产工艺及应用作一全面的阐述。     

Progress in the research of GSH in cells

Glutathione (GSH), γ-Glu-Cys-Gly, is one of the most abundant small non-protein thiol molecules in mammalian tissues, particu- larly in the liver. Although glutathione is present in thiol-reduced (GSH) and disulfide oxidized (GSSG) forms, the predominant form is GSH and its content can exceed 10 mmol/L in liver cells. As an important intracellular reductant, GSH has many biological functions in cells. Its major function is as an anti-oxidant as it can protect proteins from oxidation by reversible posttranslational modification (glutathionylation) and decrease reactive oxygen species-mediated damage. However, it does have numerous other functions, including to chelate metal irons; enhance the absorption of iron, selenium and calcium; participate in lipid and insulin metabolism; regulate cellular events such as gene expression, DNA and protein synthesis, cell proliferation and apoptosis, redox-dependent signal transduction pathways, cytokine production and the immune response; and control protein glutathionylation. Therefore, GSH plays important roles in cell survival and health, and an imbalance in the GSH level can lead to many diseases. In this review, we provide an overview of the function of GSH in mammalian cells and discuss future research of GSH.     

Progress in the research of GSH in cells

Glutathione (GSH), ??-Glu-Cys-Gly, is one of the most abundant small non-protein thiol molecules in mammalian tissues, particularly in the liver. Although glutathione is present in thiol-reduced (GSH) and disulfide oxidized (GSSG) forms, the predominant form is GSH and its content can exceed 10 mmol/L in liver cells. As an important intracellular reductant, GSH has many biological functions in cells. Its major function is as an anti-oxidant as it can protect proteins from oxidation by reversible posttranslational modification (glutathionylation) and decrease reactive oxygen species-mediated damage. However, it does have numerous other functions, including to chelate metal irons; enhance the absorption of iron, selenium and calcium; participate in lipid and insulin metabolism; regulate cellular events such as gene expression, DNA and protein synthesis, cell proliferation and apoptosis, redox-dependent signal transduction pathways, cytokine production and the immune response; and control protein glutathionylation. Therefore, GSH plays important roles in cell survival and health, and an imbalance in the GSH level can lead to many diseases. In this review, we provide an overview of the function of GSH in mammalian cells and discuss future research of GSH.     

西藏巴嘎雪湿地春季藻类群落特征研究

2010年5～7月,在西藏达孜县巴嘎雪湿地选择了7个采样站点,分两批采集水样28个,用活体观察和固定染色方法结合鉴定藻类的物种,用直接计数法统计藻类的数量,研究了巴嘎雪湿地藻类群落特征。共鉴定到藻类263种（包括12个未定名物种）,隶属于7门9纲19目36科79属。其中双壳缝目（Biraphidinales）有66种,占25．10％,为优势类群;四胞藻目（Tetrasporales）有40种,占15．21％;无壳缝目（Araphidiales）有28种,占10．65％,为次优势类群;根金藻目（Rhizochrysidales）、双星藻目（Zygnematales）为罕见类群;其余各目为常见势类群。优势种类主要有小型黄丝藻（Tribonema minus）、湖沼圆筛藻（Coscinodiscus lacusteris）、窗格平板藻（Tabellaria fenestrata）、双头针杆藻（Syned amphicephala）、尖针杆藻（Synedra acus）、新月桥弯藻（Cymbella．cymbiformis）、小桥弯藻（Cymbella laevis）、尖异极藻（G．．acuminatum var.coronata）、缢缩异极藻（Gomphonema constrictum）、纤细异极藻（Gomphonema gracile）、棒形鼓藻（Gonatozygon monotaenium）。结果表明：巴嘎雪湿地的藻类物种丰富,群落结构复杂,湿地环境健康状况良好。对藻类群落特征参数与水环境主要理化因子作相关性分析,结果表明：pH与EC（p〈0．01）、TDS（p〈0．01）、Sal（p〈0．01）呈极显著的负相关;EC与TDS（p〈0．01）、Sal（p〈0．01）呈极显著的正相关;TDS与Sal（p〈0．01）、种类数与丰富度指数（p〈0．01）、多样性指数与均匀度指数（p〈0．01）呈极显著的正相关;丰富度指数与多样性指数（P〈O．05）呈显著性正相关。