Protective effects of dietary selenium on abalone Haliotis discus hannai against the toxicity of waterborne cadmium

This study was conducted to investigate protective effects of dietary selenium (Se) on abalone Haliotis discus hannai Ino against the toxicity of cadmium (Cd). A 60‐day feeding trial was conducted with abalone (initial weight: 3.17 ± 0.01 g), which were exposed to 0.34 mg/L of waterborne Cd. During a feeding trial, abalone were fed graded levels of Se at 0.10 (controls), 1.31, and 4.20 mg/kg diet respectively. Results showed that there was no significant difference in specific growth rate and survival rate of abalone among the three treatments. Compared with the controls, dietary Se significantly decreased Cd concentrations in serum, muscle, mantle, gill, mantle, and hepatopancreas of abalone. Besides, compared with the controls, dietary Se significantly increased metallothionein concentration in the hepatopancreas of abalone. Additionally, compared with the controls, dietary Se significantly decreased concentrations of malondiadehyde and protein carbonyl in hepatopancreas of abalone. Meanwhile, compared with the controls, dietary Se significantly increased activities of glutathione peroxidase, thioredoxin reductase, and thioredoxin peroxidase, and concentration of glutathione in the hepatopancreas of abalone. Based on the data above, in abalone, dietary Se showed protective effects against waterborne Cd.     

4种福建乡土竹种的纤维形态分析

对4年生大木竹、椽竹、苦绿竹、橄榄竹的纤维长度、纤维宽度进行了显微观测与分析,结果表明,4个竹种的平均纤维长度为2.12～2.58mm,属略长至甚长纤维范畴,平均纤维宽度在11.69～12.75μm,各竹种的纤维长宽比为160～220,均适用于制纸原料。纤维形态在竹秆的不同部位存在着差别,在纵向上,竹材中部的纤维较长,基部次之,顶部居三,而纤维宽度为基部中部顶部;在径向上,纤维长度为内部外部,而纤维宽度的差异不明显。     

Cryopreservation of sperm in farmed blacklip abalone (Haliotis rubra Leach, 1814)

This study developed a technique of sperm cryopreservation using liquid nitrogen (LN) vapour in farmed blacklip abalone Haliotis rubra through evaluating the following five key factors: (1) cryoprotectant agent (CPA) toxicity; (2) cooling temperature; (3) thawing temperature; (4) sperm to egg ratio and (5) sugar addition, using sperm motility or fertilization rate as quality assessment indicators. The results demonstrated that 6% dimethyl sulfoxide (DMSO) was the best single CPA for sperm cryopreservation in this species. The highest post‐thaw sperm motility was achieved when sperm were exposed to LN vapour for 10 min at 5.2 cm above the LN surface and thawed at 60°C and recovered at 16°C in seawater baths. Post‐thaw sperm motility was found to be significantly higher when 6% DMSO was used in combination with 1% or 2% glucose than 6% DMSO alone. Further evaluation of fertilization rate between these CPAs showed that 6% DMSO+2% glucose achieved the highest fertilization rate of 70% at a sperm to egg ratio of 10 000:1.     

西藏巨柏双向电泳叶片总蛋白提取方法优化

为了获取高质量的西藏巨柏叶片蛋白质,分别采用酚抽提法、TCA/丙酮法和改良的TCA丙酮法3种方法对西藏巨柏叶片进行总蛋白的提取,同时利用蛋白试剂盒(The2-DQuantKit)对蛋白质的浓度和纯度进行了分析测定,并通过蛋白质斑点数量及分布特征,最后确定了最佳蛋白提取方法。结果表明:对样品研磨的精细程度、丙酮清洗沉淀次数等操作细节均能影响提取结果,同时采用改良的TCA丙酮法提纯后的结果最佳。说明改良的TCA丙酮法可应用于西藏巨柏叶片后续的蛋白质组学研究。     

密度及饵料对鲍苗生长与成活率的影响

研究了后期面盘幼虫不同采苗密度、不同底栖硅藻与稚鲍不同培育密度,对鲍苗的生长与成活率的影响。认为最佳采苗密度应为2万个／m2后期面盘幼虫;当地底栖硅藻混合种的饵料效果优于纯种,剥离后稚鲍的培育密度不直超过4000粒／m2。在640m2水面中有出壳长1．2～1．5cm鲍苗201．6万粒,平均出苗量3150粒／m2。专家鉴定认为,本课题在皱纹盘鲍不同育苗密度、不同饵料对育苗效果的研究方面居国内领先水平。     

Effects of dietary cholesterol on growth, survival and body composition of juvenile abalone Haliotis discus hannai Ino

An experiment was conducted to determine the dietary cholesterol requirement of juvenile abalone Haliotis discus hannai. Eight isoenergetic (18.15–18.61 kJ/g) and isonitrogenous (29.00–29.78% protein) diets, supplemented with 0.00, 0.15, 0.30, 0.45, 0.60, 0.75, 0.90 and 1.05% cholesterol were evaluated. Juvenile abalone (initial weight: 0.67–0.72 g) were reared in a flow-through water system for 24 weeks. During the feeding trial, water temperature was maintained at 14–17 °C, salinity 31–33, pH 7.4–7.9. Abalone fed diet without cholesterol supplementation had the lowest weight gain ratio (WGR, 356.70%). Survival ranged from 98.52 to 100.00% and was not significantly different among treatments. There were no significant effects of dietary cholesterol on composition and cholesterol concentration in the muscle and viscera of abalone. Based on data of WGR using broken-line analysis, the optimal dietary cholesterol requirement of juvenile abalone was found to be 0.23%.     

Effect of dietary protein and temperature on the growth and health of juvenile New Zealand black‐footed abalone (Haliotis iris)

The protein requirements for optimal growth and health of juvenile New Zealand black‐footed abalone (Haliotis iris) under different water temperatures were investigated. Six diets with different crude protein amounts (0, 10, 20, 30, 40 and 45%) and two temperature regimes (13–21 and 8–16 °C) were used to culture juvenile abalone over a 4‐month period. Growth (shell lengths and animal weights) and health (survival, activity and mucous production) parameters were recorded for animals within all protein and temperature combinations. Proximate analyses and amino acid profiles were also performed on the diets, soft bodies (including gonad), and shells to evaluate the overall nutrient contents (diet and animal) and requirements (animal). The results indicate that the protein requirements for juvenile H. iris are higher when the environmental temperatures are low. Thus, increasing the dietary protein level results in better growth [i.e. increase in soft body (including gonad) crude protein and mean protein gain] and health (i.e. more goblet cells and thicker epithelial layers). Results from amino acid profiles in abalone soft bodies (including gonad) and shells show that these parameters did not change considerably with different dietary protein levels, but temperature did affect the concentration of several amino acids in both soft bodies (including gonad) and shells.     

高锰酸钾及甲醛对九孔鲍受精卵及面盘幼虫的毒性试验

用不同浓度高锰酸钾溶液及甲醛对九孔鲍受精卵和面盘幼虫进行毒性试验。结果表明:高锰酸钾对九孔鲍受精卵的6hLC50、12hLC50分别为:2.66×10-6,2.03×10-6,;对九孔鲍面盘幼虫的24hLC50、48hLC50和安全浓度分别为:4.34×10-6,2.82×10-6,0.357×10-6,甲醛对九孔鲍面盘幼虫的24hLC50、48hLC50和安全浓度分别为:38.5×10-6,31.05×10-6,6.05×10-6。     

九孔鲍褐藻酸酶降解褐藻胶的反应条件与酶解产物的分析

以九孔鲍(Haliotis diversicoloeaquatilis)为原料制备一定纯度的褐藻酸酶,并对影响其降解褐藻胶的条件和产物的性质进行分析。该酶的最适温度和pH分别为45℃和7.0;与磷酸盐缓冲液相比,其在Tris-HCl缓冲液中与底物的亲和力相对较高。动力学曲线表明酶解反应主要发生在1 h之内,在2 h之内达到平衡,酶的剂量和底物的浓度对该平衡起到一定的影响作用。反应2 h之后,添加同数量的酶或者底物发现,产物的反馈抑制只是反应达到平衡的一个影响因素,而酶的变性失活也起到了重要的作用。金属离子对酶的活性具有明显的影响,Co2 、Mg2 对酶的活性具有较强的促进作用,而Cu2 、Ag 和Zn2 则具有较强的抑制作用。产物特性黏度的变化主要是在1 h内,2 h后基本不再改变。1HNMR图谱分析发现随着聚甘露糖片段,特别是M-M二聚体的降解,MG二聚体、GGM和MGM三聚体的量相应增多,表明该酶属于甘露糖裂解酶(EC 4.2.2.3)。