利用草鱼原代肝细胞培养评价二噁毒性效应

利用草鱼原代肝细胞培养技术评价二口恶 口英 毒性效应,测定结果与离体培养生物测试方法、高分辨质谱分析方法的测定结果进行了比较.研究结果表明,同步获得的2,3,7,8-四氯代二苯并二口恶 口英 (2,3,7,8-TCDD)对草鱼原代肝细胞和离体H4IIE细胞的EROD酶活力诱导的剂量-效应关系标准曲线,前者的EC50值比后者的EC50值高出约10倍,草鱼原代肝细胞对2,3,7,8-TCDD的灵敏度比离体H4IIE细胞的要低,2,3,7,8-TCDD对这两种细胞生物毒性效应存在着差异.测定同一环境样品中的二口

浅水湖泊中沉积物碱性磷酸酶动力学参数的分布

东湖沉积物磷酸酶在较高的pH范围内表现出较高活性 ,故为碱性磷酸酶 .东湖与严西湖沉积物中碱性磷酸酶的动力学参数表现出明显的空间异质性 ,且与间隙水和表层水中正磷酸根浓度无明显的对应关系 .此外 ,它们在垂直方向上亦极具变化 ,除在沉积物表面显示较高催化效率之外 ,较深层面 (约距表面 8- 12cm)亦有类似峰值 ,这一结果补充说明了湖泊沉积物磷循环的另一活跃区域以及相应的生物化学机制 .

鰕虎鱼寄生车轮虫两新种的记述

记述了寄生在虎鱼体表、鳃和口腔的两种新车轮虫 :一种为东湖车轮虫 ,新种 (Tri chodinadonghuensissp .nov .) ,虫体直径 49 2— 6 0 μm ,附着盘直径 44 0 (3 7 2— 51 5) μm ,齿环直径 2 2 1 (1 9 2— 2 6 4) μm ,齿体数目 2 2— 2 8个 ,以 2 3— 2 4个居多 ,辐线 8根 ,口带绕体围41 0°,大核马蹄形 ,其外径 2 0 4μm ,核臂宽 4 8— 5 4μm ,小核短杆状 ,长 2 4μm ,宽 1

草鱼不同类群淋巴细胞的分离及鉴定

用白细胞分离介质Histoque 10 77将草鱼外周血液中淋巴细胞分离后 ,依据它们对尼龙毛的粘附特性分为粘附性细胞和非粘附性细胞两个类群。分别检测分离前、后的淋巴细胞的细胞表面超微结构、α 醋酸萘酯酶活性及膜表面球蛋白。结果表明 :表面粗糙细胞、α 醋酸萘酯酶阳性细胞和膜表面球蛋白阳性 (SIg+ )细胞在外周血液总淋巴细胞中的比例分别为 47.8%、15 .2 %和 5 3.8% ,在粘附性淋巴细胞中的比例分别为 82 .3%、0 .1%和 76 .2 % ,在非粘附性淋巴细胞中的比例为 18.3%

中国鼓藻目新资料

本文报道浙江省东钱湖和西湖鼓藻目8个属的1个新种、3个新变种、20个中国新记录种及变种。

密度和温度对萼花臂尾轮虫产卵量和混交雌体的影响

用小球藻(Chlorella sp.)为食培养萼花臂尾轮虫(Brachionus calyciflorus),食物浓度约1×10~6cells/mL,温度25℃,光照强度约40001x,昼长比LD=18:6。在1.0mL、0.5mL和0.25mL培养液中同时进行单个体和群体培养。结果发现:1)单个体培养时每个母体平均产卵量分别为12.0,13.8和7.8个;后代个体中混交雌体的百分比分别是46.38％,53.49％和55.83％。2)群体培养时,每个母体平均产卵量分别为8.7、3.1和2.65个,随密度增

草鱼免疫应答的初步研究

研究了草鱼在不同水温条件下受抗原刺激后其中和抗体的变化。15℃培养条件下中和抗体上升缓慢,9周内滴度低于1:8;20℃时,3周后抗体可上升到1:256,最高达1:5270,而在25℃时,1周中和抗体即达到1:570,最高可达1:20000以上。并探索了从草鱼血清中提纯抗体的条件,研究其抗体的特性。草鱼血清中的抗体为大分子蛋白,容易解离为抗原性相同,分子量近似于人IgG的较小分子,含有较多的二硫键,具有类似IgM的某些特性。

团头鲂的胚胎及成体组织中八种同工酶系统的研究

用垂直的淀粉凝胶电泳方法分析了胚胎发育阶段(0—105小时)和成体6种组织中的乳酸脱氢酶(LDH)、苹果酸脱氢酶(MDH)、谷氨酸脱氢酶(GDH)、葡萄糖-6-磷酸脱氢酶(G6PD)、醇脱氢酶(ADH)、异柠檬酸脱氢酶(IDH)、酯酶(EST)和碱性磷酸酶(AKP)等8种同工酶系统的酶带。共约有23个基因座位在其胚胎发育期和成体组织中表达。所分析的大多数同工酶在团头鲂个体发生过程中表达的情况大致可分为3种类型:①胚胎发育期间持续存在的同工酶类,它们在成体组织中无特异性分布;②到胚胎发育后期才开始表达的同工

利用底栖动物监测严家湖农药污染

本文报道了严家湖氧化塘建成前后底栖动物群落变化,共发现寡毛类12种,水生昆虫幼虫15种,软体动物8种,其他动物2种。讨论比较3种监测方法:(1)依据底栖动物群落结构各大类的比例,提出了六级标准;(2)用群落的多样性指数,由Shannon和Weaver的公式计算,并结合化学数据比较,提出D=0,D<1,D=>1—2,D=>2—3.5,D=>3.5—5,D>5六级评价;(3)用底栖动物的残留物积累,分析不同污染带的动物(Limnodrilus hoffmeisteri,Glyptotendipes sp.,B

三种淡水枝角类生物学的研究

在恒温条件下,观察了平突船卵潘、隆线溞、微型裸腹溞的生长和繁殖。这三种淡水枝角类的生长随龄数的增加而变慢;总生活时间随温度升高而缩短。 平突船卵溞在20℃时,有3个幼龄、18个成龄、总生活时间为46.8天;30℃时为3个幼龄、15个成龄和18.8天。30℃时,隆线溞有3个幼龄、14个成龄、总生活时间为18.7天;微型裸腹溞则为2个幼龄、9个成龄和10.7天。 种类不同,累计产卵数相差很大。隆线溞在30℃时高达366个;微型裸腹溞仅为48个。平突船卵溞在20℃和30℃时分别为178个和172个。产卵率以隆线

Influence of dew on biomass and photosystem II activity of cyanobacterial crusts in the Hopq Desert, northwest China

Dew is an important water source for desert organisms in semiarid and arid regions. Both field and laboratory experiments were conducted to investigate the possible roles of dew in growth of biomass and photosynthetic activity within cyanobacterial crust. The cyanobacteria, Microcoleus vaginatus Gom. and Scytonema javanicum (Kutz.) Born et Flah., were begun with stock cultures and sequential mass cultivations, and then the field experiment was performed by inoculating the inocula onto shifting sand for forming cyanobacterial crust during late summer and autumn of 2007 in Hopq Desert, northwest China. Measurements of dew amount and Chlorophyll a content were carried out in order to evaluate the changes in crust biomass following dew. Also, we determined the activity of photosystem II(PSII) within the crust in the laboratory by simulating the desiccation/rehydration process due to dew. Results showed that the average daily dew amount as measured by the cloth-plate method (CPM) was 0.154 mm during fifty-three days and that the crust biomass fluctuated from initial inoculation of 4.3 mu g Chlorophyll a cm(-2) sand to 5.8-7.3 mu g Chlorophyll a cm(-2) crust when dew acted as the sole water source, and reached a peak value of approximately 8.2 mu g Chlorophyll a cm(-2) crust owing to rainfalls. It indicated that there was a highly significant correlation between dew amounts and crust moistures (r = 0.897 or r = 0.882, all P < 0.0001), but not a significant correlation between dew and the biomass (r = 0.246 or r = 0.257, all P > 0.05), and thus concluded that dew might only play a relatively limited role in regulating the crust biomass. Correspondingly, we found that rains significantly facilitated biomass increase of the cyanobacterial crust. Results from the simulative experiment upon rehydration showed that approximately 80% of PSII activity could be achieved within about 50 min after rehydration in the dark and at 5 degrees C, and only about 20% of the activity was light-temperature dependent. This might mean that dew was crucial for cyanobacterial crust to rapidly activate photosynthetic activity during desiccation and rehydration despite low temperatures and weak light before dawn. It also showed in this study that the cyanobacterial crusts could receive and retain more dew than sand, which depended on microclimatic characteristics and soil properties of the crusts. It may be necessary for us to fully understanding the influence of dew on regulating the growth and activity of cyanobacterial crust, and to soundly evaluate the crust's potential application in fighting desertification because of the available water due to dew. (C) 2009 Published by Elsevier Ltd.

A high throughput Nile red method for quantitative measurement of neutral lipids in microalgae

Isolation of high neutral lipid-containing microalgae is key to the commercial success of microalgae-based biofuel production. The Nile red fluorescence method has been successfully applied to the determination of lipids in certain microalgae, but has been unsuccessful in many others, particularly those with thick, rigid cell walls that prevent the penetration of the fluorescence dye. The conventional "one sample at a time" method was also time-consuming. In this study, the solvent dimethyl sulfoxide (DMSO) was introduced to microalgal samples as the stain carrier at an elevated temperature. The cellular neutral lipids were determined and quantified using a 96-well plate on a fluorescence spectrophotometer with an excitation wavelength of 530 nm and an emission wavelength of 575 run. An optimized procedure yielded a high correlation coefficient (R-2 = 0.998) with the lipid standard triolein and repeated measurements of replicates. Application of the improved method to several green algal strains gave very reproducible results with relative standard errors of 8.5%, 3.9% and 8.6%, 4.5% for repeatability and reproducibility at two concentration levels (2.0 mu g/mL and 20 mu g/mL), respectively. Moreover, the detection and quantification limits of the improved Nile red staining method were 0.8 mu g/mL and 2.0 mu g/mL for the neutral lipid standard triolein, respectively. The modified method and a conventional gravimetric determination method provided similar results on replicate samples. The 96-well plate-based Nile red method can be used as a high throughput technique for rapid screening of a broader spectrum of naturally-occurring and genetically-modified algal strains and mutants for high neutral lipid/oil production. (C) 2009 Published by Elsevier B.V.

Allelopathic effects of phenolic compounds present in submerged macrophytes on Microcystis aeruginosa

In laboratory studies, the allelopathic effects of 3 (Hydrocharitaceae family) submerged macrophytes (Elodea nuttallii (Planch) St. John, Hydrilla verticillata (L.f.) Royle and Vallisneria spiralis L.) were investigated on two strains of Microcystis aeruginosa. Both aqueous methanol extracts and exudates of three macrophytes inhibited the growth of both strains of Microcystis aeruginosa, After 3-days culture, E nuttallii, H. verticillata and V. spiralis excreted 0.8, 0.3 and 1.0% of total phenolic compounds (TPC), respectively, into the surrounding water. After removing phenolic compounds by polyvinylpolypyrrolidone (PVPP)), the plant exudates showed very weak activity. The inhibitory rates of exudates of E. nuttallii, H. verticillata and V. spiralis, against non-toxic M. aeruginosa were decreased by 35.7, 43.4 and 59.1% respectively. Thus 3 submerged macrophytes released the phenolic compounds into the surrounding water, to inhibit the growth of M. aeruginosa. This information may help us in understanding the mechanism of allelopathy in aquatic ecosystems and to control the algal bloom in eutrophic water bodies.

Spatial distribution and morphologic diversity of virioplankton in Lake Donghu, China

The spatial distribution and morphological diversity of virioplankton were determined in Lake Donghu which contains three trophic regions: hypertrophic, eutrophic and mesotrophic region. Virioplankton abundance measured by transmission electron microscope (TEM) ranged from 7.7 x 10(8) to 3.0 x 109 ml(-1), being among the highest observed in any natural aquatic system examined so far. The spatial distribution of virioplankton was correlated significantly with chlorophyll a concentration (r = 0.847; P < 0.01) at the sampling sites in Lake Donghu. 76 morphotypes were observed. Most morphotypes have tails, belonging to Siphoviridae, Myoviridae and Podoviridae. The majority of tailed phages in the lake were Myoviridae. Morphotypes which were rarely reported, such as prolate-headed virus-like particles, lemon-shaped virus-like particle, and viruses resembling Tectiviridae and Corticoviridae were all observed in the lake. It is concluded that the high viral abundance might be associated with high density of phytoplankton including algae and cyanobacteria. There was high viral diversity in this eutrophic shallow lake. In addition, cyanophage represented an important fraction of the virioplankton community in Lake Donghu. (c) 2006 Elsevier SAS. All rights reserved.

Acrossocheilus malacopterus, a new non-barred species of cyprinid from South China

Acrossocheilus malacopterus n. sp. is described from the Yuan Jiang (Red River) and Zhu Jiang basins in I South China. It is separated from other congeners by a combination of the following characters: an inconspicuously stripped body, 16 circumpeduncular scales, 47-49 lateral line scales, depth of caudal peduncle 7.8-9.3% SL, snout length 37.9-41.7% SL, dorsal-fin length 18.7-21.0% SL and last simple dorsal-fin ray slender with 8-10 fine serrations along posterior margin.