苏云金杆菌00-50-5发酵上清液对南方根结线虫杀虫活性研究

室内条件下,分别测定了苏云金杆菌Bt 00-50-5菌株液体和固体发酵物对南方根结线虫的毒力效果。结果显示,牛肉膏蛋白胨液体发酵法在72h所得上清液的毒性最高,南方根结线虫死亡率达到99.0%,而固体麸皮发酵物对线虫的最高毒性为发酵8h,南方根结线虫死亡率为89.0%。液体发酵上清液经葡聚糖凝胶G-75柱层析分离,柱下物在280nm处的吸收值呈现出4个峰I、II、III和IV,其值0.601,1.475,1.641和0.392,其中峰II、III、IV处收集的蛋白对南方根结线虫有毒杀作用,分子量最小的IV蛋白杀线虫活性最高。上清液天然聚丙烯酰胺凝胶电泳分离杀虫蛋白结果显示6条清晰蛋白带,其中37kDa蛋白含量最多。     

高原农作物豌豆抗氧化和脂质过氧化研究

1材料与方法 1．1材料供试豌豆产于西宁互助,海拔3600m;供试小鼠体重18-22g,雌雄对半,由青海动物养殖场提供。     

Susceptibility of Caspian Roach (Rutilus rutilus caspicus) Fingerlings to Formalin

ABSTRACT

Caspian roach (Rutilus rutilus caspicus) were exposed to 0, 30, 40, 45, 50, 55, 60, 70, 100, 150 200, 250, 300, and 400 ppm formalin to determine LC₅₀. Respectively, 0.5 to 96 h LC₅₀ values were 252 to 49 ppm. The lowest observed effect concentrations (LOEC) and no observed effect concentrations (NOEC) varied between 40 to 150 and 30 to 100 ppm, respectively, across the tested time spectrum. Regression suggested that the concentrations of 88.4, 80.3, 51.2, and 40.1 ppm are maximum concentrations for 0.5, 1, 12, and 24 h bath treatment, respectively, which are not in the range suggested in the literature.     

染发废水对鲤鱼急性毒性试验研究

以鲤鱼为受试生物,将其暴露于不同浓度的染发废水中,通过半静止式试验,根据鲤鱼在各时间段的死亡率求出半致死浓度、安全浓度以及毒性累积程度系数等特征参数,探讨染发废水对鲤鱼的急性毒性,评价染发废水的毒性等级。结果表明:染发废水急性毒性等级为中等毒;染发废水在48 h内稳定性较差,48 h后才能趋于完全稳定;染发废水对鱼类急性毒性试验时间至少可缩短至48 h。     

Effect of temperature on copper toxicity and hematological responses in the neotropical fish Prochilodus scrofa at low and high pH

Copper sulfate has been widely used to control algae and pathogens in fish culture ponds. However, its toxic effects on fish depend not only on its concentration in water but also on water quality. The susceptibility of the neotropical freshwater fish Prochilodus scrofa to copper was evaluated at two temperatures with low and high water pH. Juvenile fish were acclimated at 20 and 30 °C and exposed to copper (static bioassay system) in water with pH 4.5 and 8.0. The 96 h-LC₅₀ were determined at each temperature and pH, as were the hematological parameters. The 96 h-LC₅₀ for copper (98 and 88 μg Cu L^− 1 in water with pH 4.5 and 16 and 14 μg Cu L^− 1 in water with pH 8.0 for fish kept at 20 and 30 °C, respectively) was significantly dissimilar in pH 4.5 and 8.0, but no difference was found between 20 and 30 °C in the same water pH. At 20 °C, regardless of the water pH, the hematocrit (Hct) increased while the red blood cells (RBC) and hemoglobin (Hb) concentration decreased compared to control pH 7.0. Copper exposure in water pH 4.5 and 8.0 causes an increase on the Hct, RBC and Hb concentrations in relation to the controls pH 4.5 and 8.0. At 30 °C, the changes on the blood parameters depended on the water pH and, after copper exposure at low and high pH, the blood changes indicated more complex responses. The changes in hematological parameters of the fish, regardless of the pH and water temperature, indicate ionoregulatory or respiratory disturbances that imply an increase in energy consumption to restore homeostasis instead of other physiological functions such as weight gain and growth.     

Cu2+和Cd2+对斑节对虾幼虾的毒性作用

研究了Cu^2 和Cd^2 对斑节对虾幼虾 的急性和亚急性毒性作用，获得了Cu^2 和Cd^2 的半致死浓度、安全浓度和累积量。     

急性硫化物胁迫对日本沼虾免疫和抗氧化系统的影响

日本沼虾（Macrobrachium nipponense）在硫化物浓度为0.4、1.2和4.0mg/L的水体中暴露48h,研究硫化物胁迫对其血液免疫指标和机体抗氧化能力的影响。结果表明,硫化物对日本沼虾的24、48、72、96hLC50分别为22.5、15.2、12.5、11.35mg/L。血细胞密度（THC）和吞噬活力（吞噬百分比和吞噬指数）随硫化物质量浓度升高而降低,至48h,0.4、1.2和4.0mg/L组的THC显著降低,分别为对照组的85.71%、70.75%和57.48%。各试验组沼虾的凝血时间与对照组相比延长,1.2mg/L和4.0mg/L组分别从12h和6h开始显著长于对照组（P〈0.05）。沼虾肌肉中的总抗氧化能力（T-AOC）随硫化物浓度的升高而降低,至48h,1.2mg/L和4.0mg/L组显著低于对照组（P〈0.05）。超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活力随硫化物浓度的升高而增强,至48h,1.2mg/L和4.0mg/L组的SOD活力显著高于对照组（P〈0.05）,表明日本沼虾免疫系统对低浓度硫化物有一定的耐受力;当硫化物浓度过高时,沼虾的免疫能力降低,对机体抗氧化系统产生显著影响。     

纳米硒对斑马鱼胚胎毒性的研究

为研究纳米硒对斑马鱼胚胎毒性大小,使用光镜和电镜等技术对硒代蛋氨酸和纳米硒进行了比较研究。结果显示,纳米硒粒子的粒径分布均匀,平均粒径约25nm。纳米硒在斑马鱼受精后96小时和120小时的半数致死浓度分别为7.18μM和5.68μM;而DL-硒代蛋氨酸在斑马鱼受精后96小时和120小时的半数致死浓度分别为67.32μM和54.66μM。此外,在斑马鱼受精后120小时,纳米硒和DL-硒代蛋氨酸的半数致畸浓度分别为3.27μM和44.22μM。研究表明,在直接暴露的条件下,纳米硒的毒性要大于DL-硒代蛋氨酸。研究旨在为纳米硒的安全应用奠定一定的基础,扩充水产动物毒理学相关理论。     

谈对半成品抗原半数感染量判定方法的理解

在兽用生物制品生产中,常用病毒半数感染量（EID50）来表示病毒类疫苗及其半成品抗原的效价,作者以鸡新城疫活疫苗为例,对其半成品抗原及成品EID50的判定方法进行比较分析,加深了对准确表达每毫升半成品抗原病毒含量判定方法的理解。     

香橼优良单株半同胞家系子代抗寒性研究

在南京六合地区对3年生24个香橼优良单株半同胞家系子代进行抗寒性测定研究,结果表明家系子代间抗寒性存在着显著的差异。田间观测-11℃自然低温下春江4#和香橼4#的抗寒性最强,受冻株率分别为86.67%和100%,平均受冻级别均为Ⅰ级,耐寒指数均为2.00;新世纪8#、春江7#和新世纪2#的抗寒性最差,受冻株率均为100%,平均受冻级别均达Ⅲ级,耐寒指数均大于3.00。室内抗寒力测定供试家系子代的半致死温度在-14.84℃～-7.05℃之间。春江4#和香橼4#的抗寒力最强,半致死温度分别为-14.84℃和-13.94℃;春江7#和新世纪2#的抗寒力最差,半致死温度分别为-7.91℃和-7.05℃。抗寒性评估结果一致。根据半致死温度,结合田间抗寒性观测,供试香橼家系子代抗寒性评估排序为春江4#>香橼4#>春江6#>春江5#>新世纪9#>新世纪10#>新世纪3#>香橼1#>新世纪7#>香橼7#>新世纪8#>香橼6#>香橼5#>春江3#>新世纪4#>新世纪6#>香橼2#>春江8#>新世纪5#>春江1#>新世纪1#>春江2#>春江7#>新世纪2#。