双条杉天牛对不同提取法所得侧柏挥发油的触角电位反应

分别用水蒸气蒸馏法和索氏提取法提取侧柏树干部分的挥发性物质,测定双条杉天牛成虫对所提两种挥发油及侧柏木屑的触角电位(EAG)反应。结果表明,水蒸气蒸馏法所得挥发油与侧柏木屑均能引起双条杉天牛的EAG反应,但以挥发油引起的反应较强,在一定范围内EAG反应强度与挥发油剂量呈正相关;双条杉天牛对索氏提取法所得挥发油不产生显著反应;同种样品,雌虫的EAG反应略强于雄虫,但差异不显著。     

腐殖酸强化脱硫石膏改良油污盐碱土壤的研究

以腐殖酸为表面活性剂进行了脱硫石膏改良油污盐碱土壤的土柱实验,研究了不同洗盐条件下土壤渗透性能、电导率和pH值的变化规律。研究结果表明,油污显著影响脱硫石膏改良盐碱土壤的效果,淋洗前后油污土壤的碱化度仅从42.78%下降到37.72%;而加入腐殖酸表面活性剂后,油污盐碱土壤碱化度由42.78%下降到23.20%,淋出液电导率值显著增高,且pH值有所变化,证明加入腐殖酸表面活性剂可显著强化脱硫石膏改良油污盐碱土壤。     

Molecular cloning,characterization and nutritional regulation of key enzymes required for the effective utilization of marine wax esters by Atlantic salmon (Salmo salar L.)

Previous studies had shown that wax ester‐rich lipid extracted from calanoid copepods could be a useful alternative to fish oil as a provider of long‐chain n‐3 polyunsaturated fatty acids in diets for use in salmon aquaculture. Effective utilization of wax ester requires digestion and metabolism in the intestine with the fatty alcohol component being oxidized to fatty acid in intestinal cells through the combined activities of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). We studied wax ester utilization in Atlantic salmon using a candidate gene approach, focusing on ADH and ALDH as sequence information was available for these genes, including fish sequences, facilitating isolation of the cDNAs. Here, we report on the isolation and cloning of full‐length cDNAs for ADH3 and ALDH3a2 genes from salmon intestinal tissue. Functional characterization by heterologous expression in the yeast, Saccharomyces cerevisiae, showed the products of these cDNAs had long‐chain ADH and ALDH enzyme activities. Thus, ADH3 was capable of oxidizing long‐chain fatty alcohol, and ALDH3a2 was capable of oxidizing long‐chain fatty aldehyde to the corresponding fatty acid. The genes were highly expressed in intestinal tissue, particularly pyloric caeca, but their expression was not increased in salmon fed dietary copepod oil in comparison to fish fed fish oil.     

蓖麻油聚氨酯丙烯酸酯复合乳液的研制

采用甲基丙烯酸甲酯(MMA)与蓖麻油水性聚氨酯共聚反应制备蓖麻油聚氨酯丙烯酸酯(CPUA)复合乳液,研究了蓖麻油添加量、MMA添加量和引发剂种类对合成CPUA复合乳液及涂膜性能的影响,并应用傅立叶红外光谱(FT-IR)测定反应产物的结构.研究发现随着蓖麻油和MMA添加量增大,CPUA复合乳液胶粒平均粒径增大,粘度减小,涂膜光泽度下降,机械性能和耐水性增强,确定了合适的蓖麻油和MMA含量,分别为体系总固体质量的20%～25%和20%～30%.采用偶氮二异丁腈(AIBN)和过硫酸钾(KPS)复合引发剂可提高单体的转化率;性能测试表明,本研究合成的CPUA复合乳液具有优异的物理机械性能和耐水性.     

GC-MS法测定余杭栝楼根块的挥发油成分

用95%乙醇提取栝楼根块,然后用石油醚萃取得石油醚部分,采用常规水蒸气蒸馏法提取其挥发油,采用毛细管GC-MS法分离出128个峰,确认了其中45种成分,所鉴定的组分占总峰面积的82.75%.     

饲料脂肪源和碘酸钾对中华鳖稚鳖生长、存活率、肝肠组织形态和脂类代谢的影响

为了比较饲料中添加鱼油、茶籽油、亚麻籽油以及碘酸钾对中华鳖（）稚鳖生长和脂类代谢的影响,本研究配制了4种油脂含量为10%的饲料,分别为鱼油料（FO,对照组）、鱼油+碘酸钾料（FO+PI,碘酸钾添加量为75 mg/kg）、茶籽油料（TO）和亚麻籽油料（LO）,饲喂初重为（5.06±0.05）g的中华鳖66 d。FO+PI组和LO组中华鳖稚鳖的存活率显著低于FO组（<0.05）。各组中华鳖稚鳖血浆中葡萄糖、总胆固醇和甘油三酯水平无显著差异（ACACA）的表达水平,上调了中华鳖-499的表达水平（-23b的表达水平（<0.05）。FO+PI组和TO组的稚鳖肝脏细胞内脂滴空泡较少,同时TO显著影响了肠道组织的黏膜褶。结论认为,相比于鱼油组,在饲料中添加10%茶籽油、亚麻籽油和添加75 mg/kg碘酸钾不会引起稚鳖生长差异,但是亚麻籽油和碘酸钾降低了稚鳖的存活率,茶籽油和碘酸钾影响肝脏的脂类代谢。     

Effects of ferulic acid on growth performance,immunity and antioxidant status in genetically improved farmed tilapia (Oreochromis niloticus) fed oxidized fish oil

A study was conducted to characterize the effects of dietary oxidized fish oil on the growth performance, immunity and antioxidant status of genetically improved farmed tilapia (Oreochromis niloticus) and to determine the role of ferulic acid on the oxidative damage induced by the oxidized fish oil. The tilapia (13.73 ± 0.31 g) were fed four experimental diets containing untreated (peroxide value, POV: 2.2 meq/kg) and highly oxidized (POV: 120.6 meq/kg) fish oil either with or without ferulic acid (0 or 400 mg/kg) supplementation for 12 weeks. From the results, the oxidized fish oil treatments increased antioxidant enzyme activities and MDA values but decreased the weight gain and the immunological parameters in tilapia. Meanwhile, the serum biochemical indices were significantly affected by the oxidized fish oil. Besides, the addition of ferulic acid partially counteracted the free radical‐induced damage and improved the health status of tilapia. In conclusion, the oxidized fish oil may induce oxidative stress, destroy liver, dysregulate lipid metabolism as well as reduce non‐specific immunity, and eventually result in growth inhibition of tilapia. The ferulic acid supplementation partially offset the negative effects of the oxidized fish oil on tilapia.     

Effect of oil source on growth performance,antioxidant capacity,fatty acid composition and fillet quality of juvenile grass carp (Ctenopharyngodon idella)

This study was conducted to evaluate the dietary use of vegetable oil sources in grass carp (Ctenopharyngodon idella). Fish were fed diets having the same lipid level from fish oil (FO), palm oil (PO), rapeseed oil (RO), soybean oil (SO) or linseed oil (LO). The results showed that dietary vegetable oils significantly decreased the feed utilization and a significantly lower growth was observed in SO group, while palm oil showed no effect on the growth performance. Dietary vegetable oils suppressed intestinal digestion by inhibiting the activities of digestive enzymes. Vegetable oils significantly elevated the activities of lipase, hepatic lipase and total lipase in liver, and a phenomenon of intense lipid accumulation emerged in liver of PO and SO groups. Furthermore, linseed oil significantly decreased plasma antioxidant capacity, whereas no significant difference was found between RO and FO groups. Dietary vegetable oils caused a significantly lower EPA and DHA in muscle, and further influenced fillet quality through an increase in cohesiveness, gumminess, chewiness and/or springiness, together with a decrease in hardness. Overall, our results indicated that rapeseed oil may be a suitable alternative oil source for grass carp from a point of growth, feed conversion ratio, antioxidative capacity and hepatic histology.     

The effects of the tank colour on growth performance and physiological responses in fingerling grouper,Epinephelus coioides

In this study, the effects of different background colours on growth performance and physiological parameters of Epinephelus coioides were investigated. One hundred eighty E. coioides (average weight 18.16 ± 0.07 g) were distributed in black, white and blue 300‐L tanks and fed to satiation for 60 days. The tank colour had no significant effect on the weight gain, condition factor, hepatosomatic index and specific growth rate (p > .05). The lowest amount of viscerosomatic index and the highest carcass protein were recorded in the white tank (p < .05). Daily food intake, feed conversion ratio and plasma glucose were significantly higher in the blue tank (p < .05). The highest levels of haematocrit and plasma triglyceride were observed in the white tank, while the total protein and albumin were higher in the black tank compared to the other tanks. The tank colour had no significant effects on the plasma cortisol level (p > .05). Our findings showed that colours used in this study did not evoke stress and thus had no effect on growth, but some metabolic adaptation occurred in each colour to achieve optimum growth.