Effects of Dietary Carbohydrates Sources on Lipids Compositions in Abalone, Haliotis discus hannai Ino

A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohydrates (dextrin, heat-treated wheat starch, wheat starch, corn starch, tapioca starch and potato starch, respectively), all containing a carbohydrate level of 33.5%, were fed to abalone (initial shell length: 29.98 mm±0.09 mm; initial weight. 3.42 g±0.02 g) for 24 weeks in a recirculation system. The results indicate that serum triglyceride concentrations were significantly (P<0.05) higher in the abalone fed with dextrin, heat-treated wheat starch and wheat starch than those fed with corn starch, and serum cholesterol concentrations were significantly (P<0.05)higher in the abalone fed with dextrin, heat-treated wheat starch than those fed with corn starch. Fatty acid C20:4n-6 in the foot muscles were significantly (P<0.05) lower in the abalone fed with dextrin than those fed with wheat starch, corn starch, tapioca starch and potato starch. Fatty acid C20:4n-6 in hepatopancreas was significantly (P<0.05) lower in abalone fed with heat-treated wheat starch than those fed with corn starch, tapioca starch and potato starch. Fatty acid C22:6n-3 in the foot muscles were significantly (P< 0.05) lower in the abalone fed with dextrin and heat-treated wheat starch than those fed with wheat starch and potato starch.     

Measurement of Trace Manganese(Ⅱ) by the Catalytic Kinetic Spectrophotometric Method

A new kinetic spectrophotometric method is developed for the measurement of manganese (Ⅱ) in water. The method is based on the catalytic effect of manganese (Ⅱ) with the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 using the Nitrilo triacetic acid (NTA) as an activation reagent. The optimum conditions obtained are 40mgL-1 RAWL, 1×10-4molL-1 KIO4, 2×10-4molL-1 Nitrilo triacetic acid (NTA), pH = 5.8, the reaction time of 3.00 min and the temperature of 20.0 ℃. Under the optimum con-ditions, the proposed method allows the measurement of manganese (Ⅱ) in a range of 0-50.0ngmL-1 and with a detection limit of down to 0.158 ng mL-1. The recovery efficiency in measuring the standard manganese (Ⅱ) solution is in a range of 98.5%-102%, and the RSD is in a range of 0.76%-1.25%. The new method has been successfully applied to the measurement of manganese (Ⅱ) in both fresh water and seawater samples with satisfying results. Moreover, few cations and anions interfere with the measurement of man-ganese (Ⅱ). Compared with other kinetic catalytic methods and instrumental methods, the proposed method shows fairly good selec-tivity and sensitivity, low cost, cheapness, low detection limit and rapidity. It can be applied on boats easily.     

哈维氏弧菌对条纹斑竹鲨4种酶活性的影响

以哈维氏弧菌（Vibrio harveyi）对条纹斑竹鲨（Chiloscyllium plagiosum）进行病原接种试验,分别在4、8、12、24、48、72、96h后测定肝脏、脾脏、鳃及血清的酸性磷酸酶（acid phosphatase,ACP）、碱性磷酸酶（alkaline phosphatase,AKP）、超氧化物歧化酶（superoxide dismutase,SOD）和血清中溶菌酶（lysozyme,LSZ）的活力.实验结果表明：对照组条纹斑竹鲨的这4种酶的活力呈现出明显的组织差异性,血清中SOD活力为124.32 U/cm3,显著高于其他3种酶的活力;其他组织中3种酶的活力由高到低依次为SOD、ACP、AKP.在实验组条纹斑竹鲨被感染4～72h期间,血清中SOD活力明显下降,ACP活力持续下降,感染96h后除LSZ外,其他3种酶的活力都呈回升趋势;其他组织中ACP与AKP活力变化均为被感染4h后下降,12h后明显回升,SOD则在被感染4h后活力上升,而后下降,96h后回升.这4种酶的活力的变化主要是应激作用与非特异性免疫防御作用共同作用导致的结果.     

驼背鲈肌肉营养成分的分析与评价

采用生物化学方法测定和分析了驼背鲈（Cromileptes altivelis）肌肉的营养成分.结果显示,每100 g驼背鲈肌肉的干物质含量：粗蛋白为84.51 g、粗脂肪为5.28 g、VE为5.59 mg、VB2为0.61 mg、钙为69.60 mg、磷为757 mg、钾为1 490 mg、钠为142 mg、铁为1.05 mg、硒为0.21 mg,钙/磷含量比为1/10.88.驼背鲈肌肉的营养成分属于高蛋白低脂肪类型,肌肉的必需氨基酸模式3 001.31 mg/g优于FAO-WHO的理想模式2 190 mg/g,氨基酸的支/芳值为2.41接近正常人体的水平,氨基酸含量（97.49%）、必需氨基酸含量（48.33%）和鲜味氨基酸含量（37.37%）均较高,氨基酸种类齐全,肉味鲜美,不饱和脂肪酸含量（13.61%）较低.结果表明,驼背鲈肌肉具有较高的营养价值,属于一种优质的海产蛋白源.     

红树植物红海榄叶化学组成研究

对红树植物红海榄叶的基本化学成分水分,灰分,灰分中酸不溶物,灰分中S(SO42-),粗蛋白,粗脂肪等及氨基酸和微量元素的组成和含量进行了系统的分析测定。其基本化学组成各成分含量分别为:水分(69.18%),灰分(3.04%),灰分中酸不溶物(0.094%),灰分中S(SO42-)(0.052%),粗脂肪(7.75%),粗蛋白(7.14%);测得了红海榄叶中17种氨基酸,其总含量为10.7mg/g,其中人体必须氨基酸有7种,占所含氨基酸总量约26%;采用全谱直读等离子体原子发射光谱仪对红海榄叶进行了31种微量元素的分析测定,测得了其中18种元素的含量,红海榄叶中含有丰富的人体必须的矿物质元素。     

Effects of Nutritional Factors on the Growth and Heterotrophic Eicosapentaenoic Acid Production of Diatom Nitzschia laevis

The effects of several nutritional factors on the growth and eicosapentaenoic acid (EPA) production of diatom Nitzschia laevis were studied. 4 LDM (quadrupled concentration of the nutrient salt) was the optimal concentration of nutrient salt for the growth and EPA production ofN. laevis. The growth ofN. laevis was inhibited when the glucose concentration was either lower than 10gL-1 or higher than 15gL-1. Both sodium nitrate and urea were good nitrogen sources for the growth and EPA production, while ammonium chloride seriously decreased the dry cell weight (DW) and the EPA content. Silicate seriously influenced the growth of N. laevis. The maximum DW of 2.34gL-1 was obtained in the presence of 150 mgL-1 Na2SiO3·9H2O. The EPA content remained almost the same when the silicate concentration was lower than 150 mgL-1; however, higher silicate concentrations resulted in a steady de- crease of EPA content. Low medium salinity (≤29) did not seem to influence the DW of N. laevis, and high salinity resulted in a decrease of DW. The highest EPA content (4.08%) and yield (110 mgL-1) were observed at the salinity of 36 and 29, respectively.     

桑沟湾养殖栉孔扇贝食物来源研究——脂肪酸标志法

运用脂肪酸标志法分析了桑沟湾养殖栉孔扇贝(Chlamys farreri)春、夏季食物来源组成。结果表明,桑沟湾养殖栉孔扇贝饵料组成中含有硅藻类、细菌、大型绿藻类、鞭毛藻类等饵料来源,且各种饵料来源比例具有较显著的季节变化。采样期间硅藻脂肪酸标志16:1/16:0(相对质量分数比,下同)从0.91降至0.45,表明扇贝硅藻类饵料来源比例呈逐渐下降趋势;细菌脂肪酸标志18:1n-7/18:1n-9比值从0.31升至0.90,奇数碳、支链脂肪酸相对质量分数从2.15%升至3.28%,表明扇贝细菌类饵料来源比例呈逐渐上升趋势;绿藻脂肪酸标志Σ(18:2n-6 18:3n-3)质量分数从2.78%升至5.77%,表明大型绿藻来源有机质饵料比例逐渐上升。栉孔扇贝脂肪酸组成中较高比例的DHA表明扇贝摄取了富含DHA的有机质,如鞭毛藻类、微型浮游动物等。栉孔扇贝食物来源的季节变化很可能是由水体中潜在食物来源的季节变化所导致。     

掺硼金刚石膜电极降解水中全氟辛酸

采用掺硼金刚石膜电极(Boron-doped diamond,BDD)为阳极的电化学氧化法降解全氟辛酸(Perfluorooctanoic acid,PFOA);对比不同电解质体系中PFOA的脱氟效果,考察初始pH、流速、电流密度、初始浓度和电解质浓度对PFOA脱氟率的影响,估算体系能耗;以甲醇(MeOH)和叔丁醇(TBA)为淬灭剂进行自由基淬灭实验,分析PFOA的降解机理。结果表明:Na2SO4电解质体系中,PFOA具有良好的降解效果;酸性条件下(pH为3~4.2)PFOA脱氟效果较佳,中性条件下较差,脱氟效果随初始浓度的增加而降低,随电流密度的增大先提升后趋于稳定。初始pH为3、电流密度30 mA·cm^-2、流速32.5 mL·min^-1、初始浓度100 mg·L^-1、Na2SO4浓度0.05 mol·L^-1条件下,电解180 min,PFOA脱氟率达53.45%,能耗约为1.13 kWh·(g F)-1;硫酸盐体系产生的·OH、SO-4·两种自由基均能氧化降解PFOA。     

天津市酸雨及其成因初探

根据1992年6月到2004年12月的酸雨观测记录,对近10余年天津市酸雨的变化规律和趋势进行了统计分析。结果表明:天津市酸雨发生呈明显的季节性变化,酸雨发生频次和强度呈现不同的季节变化趋势,酸雨主要分布在夏秋两季,但酸雨较强的季节却是在秋冬季;天津市酸雨呈逐年减少趋势,进一步的分析表明天津地区SO2排放量的逐年减少是酸雨减弱的主要原因。