南海8种低值小杂鱼脂肪含量和脂肪酸组成分析

采用氯仿-甲醇法提取南海盛产的8种低值小杂鱼肌肉、鱼头、内脏中的粗脂肪,利用气相色谱分析其脂肪酸的组成。结果表明,低值小杂鱼头部粗脂肪含量为2.7%～9.7%,内脏粗脂肪含量为2.9%～6.2%,肌肉部分粗脂肪含量为2.0%～8.5%;不同低值小杂鱼的脂肪酸组成基本相同,但其含量有所差异,饱和脂肪酸含量最高,都在40%以上,内脏粗脂肪中的饱和脂肪酸含量较头部和肌肉中的含量高;多不饱和脂肪酸含量差异较大,粗脂肪含量较高的鱼中多不饱和脂肪酸的含量较低;不同鱼种不同部位的粗脂肪中EPA、DHA含量有所差异。蓝圆鲹的头部粗脂肪中DHA和EPA最高,含量达到28.4%,而双带海鲱鲤内脏粗脂肪中的EPA和DHA含量仅为7.26%。     

稚鱼生物饵料的DHA营养强化

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。     

巨大芽孢杆菌MPF-906对养鱼水质净化的初步研究

以鲫鱼为对象,利用从水产养殖水体中分离得到的巨大芽孢杆菌MPF-906,研究了其微生态制剂同步净化养鱼水质的动态变化。结果显示,在水族箱中添加巨大芽孢杆菌MPF-906制剂后,与对照组相比,水中的亚硝酸盐显著降解,COD也有所下降,pH值稳定在7.78￣8.19之间,表明巨大芽孢杆菌微生态制剂对净化养鱼水质和调节养殖水体微生态结构稳定具有明显的作用,其最适使用浓度为4×108CFU/mL。     

抑制消减杂交（SSH）及其在鱼类基因克隆中的应用

和其它脊椎动物一样,在鱼类的生命进程中,某种特定类型的细胞中只有比例约为10%～15%的基因表达.由于这些基因的特异性决定了从受精卵到机体死亡的整个生命过程,所以这些基因的时空表达是受到严格调控的.在不同发育阶段,不同生理状态和不同类型的细胞中,表达的基因各不相同.因此,比较两种不同类型细胞中基因表达的差异,可以探究表型的遗传原因,了解生命过程的基本信息,从而找到与发育、疾病等相关的基因.     

Effect of extrusion cooking temperature on the microstructure of extruded pellets

ABSTRACT:   The microstructure of extruded pellets (EP) for fish under various extrusion cooking temperatures was studied by using a twin-shaft extruder. As the extrusion cooking temperature increased, the expansion rate increased and the bulk density of EP decreased. The liquefaction of the material started because of the increase in inner material temperature, the decrease in inner material pressure, and the decrease in main motor amperage. Thus, the microstructure of EP changed depending on the extrusion cooking conditions, that is, the extrusion cooking temperature effected greatly the liquefaction of the material. Generally, when the extrusion cooking temperature increased, the expansion rate increased, but a suitable temperature was found for a maximum expansion rate. The microstructure of the EP was caused by the liquefaction of the material and the microstructure effects on the function of EP. For example, the water holding capacity was affected by the inner bubble structure of an EP. These functions affect the character of the feed. EP produced under suitable conditions can have additional functions for feed.     

鱼类弹状病毒分子生物学研究动态

鱼类弹状病毒(Fish rhabdovirus)是一类引起鱼及其他水生动物致死性和流行性病害的重要病毒病原。对鱼类弹状病毒基因组的结构和功能研究,是深入探讨这类病毒感染和致病机理、研制病毒疫苗及诊断试剂的理论基础。本文就鱼类弹状病毒的基因组结构,包括N基因、P基因、M基因、G基因、NV基因、L基因及编码的相应蛋白、3′前导区和5′拖尾区、基因连接区等的组成及功能的研究进展作一综述,旨为抗病毒疫苗的研制及建立准确高效的检测方法提供借鉴。     

Effects of incremental amounts of fish oil on trans fatty acids and Butyrivibrio bacteria in continuous culture fermenters

Previous studies have shown that adding fish oil (FO) to ruminant animal diets increased vaccenic acid (VA; t11 C18:1) accumulation in the rumen. Therefore, the objective of this study was to evaluate the effect of dietary FO amounts on selected strains of rumen bacteria involved in biohydrogenation. A single‐flow continuous culture system consisting of four fermenters was used in a 4 × 4 Latin square design with four 9 days consecutive periods. Treatment diets were as follows: (i) control diet (53:47 forage to concentrate; CON), (ii) control plus FO at 0.5% (DM basis; FOL), (iii) control plus FO at 2% (DM basis; FOM) and (iv) control plus FO at 3.5% (DM basis; FOH). Fermenters were fed treatment diets three times daily at 120 g/day. Samples were collected from each fermenter on day 9 of each period at 1.5, 3 and 6 h post‐morning feeding and then composited into one sample per fermenter. Increasing dietary FO amounts resulted in a linear decrease in acetate and isobutyrate concentrations and a linear decrease in acetate‐to‐propionate ratio. Propionate, butyrate, valerate and isovalerate concentrations were not affected by FO supplementation. Concentrations of C18:0 in fermenters linearly decreased, while concentrations of t10 C18:1 and VA linearly increased as dietary FO amounts increased. The concentrations of c9t11 and t10c12 conjugated linoleic acid were not affected by FO supplementation. The DNA abundance for Butyrivibrio fibrisolvens, Butyrivibrio vaccenic acid subgroup, Butyrivibrio stearic acid subgroup and Butyrivibrio proteoclasticus linearly decreased as dietary FO amounts increased. In conclusion, FO effects on trans fatty acid accumulation in the rumen may be explained in part by FO influence on Butyrivibrio group.     

复合氨基酸、小肽及中草药饲喂鲫试验

以鲫为对象进行投饲试验，研究复合氨基酸、小肽及几种中草药对鲫在摄食方面及生长情况的影响。结果表明，0．1％复合氨基酸组和0．5％木香组的鱼明显集中抢食，15d的摄食率结果为0．1％复合氨基酸组和0．5％木香组的鱼体活力明显强于其他组，即0．1％复合氨基酸和0．5％木香组的鱼增重率和特定生长率（SGR）明显高于其他组。饲料中添加0．5％木香组比对照组增重率高18．9％，比0．1％复合氨基酸组高6．3％，表现出明显的增重作用；而0．5％动物肽纽增重可能由于添加量的不足而没体现出增重作用。     

一种低值鱼鳔蛋白的酶解工艺试验研究

鱼鳔是重要的药食两用水产品资源,但加工产品单一。为了提高鱼鳔的深加工利用水平,以海南市场上一种低值鱼鳔为原料,研究了鱼鳔蛋白的酶解工艺。通过测定鱼鳔蛋白酶解过程中的氨基氮、可溶性固形物、滤速等参数的变化,分析不同的反应条件对鱼鳔蛋白降解结果的影响规律。结果显示,反应过程中可溶性固形物含量比氨基氮含量提前达最大值;复合蛋白酶降解鱼鳔蛋白的较适条件是:起始pH值5.0~7.0,温度50~60℃,酶量范围为0.7%~0.8%,反应时间5 h,底物浓度3%。