Fish meal replacement by plant and animal by-products in diets for the Australian short-finned eel, Anguilla australis australis (Richardson)

In this experiment, 23% of fish meal protein was replaced with protein from Australian soybean meal (SBM), lupin meal (LM), corn gluten meal (CGM) and meat meal (MM) in nutritionally balanced experimental diets. Growth and growth efficiencies of juvenile Australian short‐finned eel Anguilla australis australis (Richardson) elvers (2.23±0.4‐g average wet weight) were compared. Elvers were fed twice a day to a total of 5% body weight per day for 63 days. Total weight gain (g), specific growth rate (% day^?1), protein efficiency ratio (%) and productive protein value (%) were significantly higher (P<0.05) for elvers fed the MM diet than for those fed the LM diet. There were no differences in diurnal ammonia‐nitrogen excretion rates. However, diurnal urea‐nitrogen excretion rates were significantly (P<0.05) affected by diet and rates were two to three times higher for all diets, except CGM, 4 h following the afternoon feed. Diet significantly affected apparent digestibility (AD); ADs of protein for SBM and LM were significantly (P<0.001) higher than for control diet, CGM and MM; AD of energy for LM was significantly (P<0.05) lower than for all the other diets. Fish meal protein was replaced by CGM, SBM and MM without compromising growth rates of the Australian short‐finned eel. However, whole lupin seed meal (LM) depressed growth and growth efficiencies most likely because of the high indigestible carbohydrate content.     

海藻糖对冻藏过程中鳙肌原纤维蛋白冷冻变性的影响

从鳙（Aristicktkys nobilis）肌肉中提取肌原纤维蛋白，在蛋白溶液中加入10％（W／V）蔗糖、山梨醇混合物（质量比1：1）或10％（W／V）海藻糖。蛋白溶液在-18℃下冻藏30d，测定冻藏过程中肌原纤维蛋白盐溶性、Ca^2＋-ATPase活性、活性巯基含量、总巯基含量、表面疏水性变化和冻藏结束时的SDS-PAGE。测定结果表明，蔗糖、山梨醇混合物和海藻糖都抑制了冻藏过程中肌原纤维蛋白盐溶性、Ca^2＋-ATPase活性、巯基含量的降低和表面疏水性的升高，延缓了鳙肌原纤维蛋白的冷冻变性。海藻糖比蔗糖、山梨醇混合物有更好的抗冷冻变性效果。[中国水产科学，2006，13（4）：637—641]     

牙鲆淋巴囊肿病毒一抗原蛋白的确认及定位

以牙鲆淋巴囊肿病毒（LCDV）为抗原免疫Balb/c小鼠，而后将小鼠脾细胞与P3U1骨髓瘤细胞融合，以囊肿组织冰冻切片的免疫荧光染色筛选杂交瘤细胞，阳性结果显示特异性块状荧光信号集中在囊肿细胞的细胞质边缘部分，且多个荧光信号相连呈现链圈状，有限稀释 法克隆阳性杂交瘤细胞，三次克隆后获得4株稳定产生抗LCDV抗体的单克隆杂交瘤细胞株（1A8、1D7、2B6、2D11）。应用Western-blotting法分析单抗识别蛋白的分子量，结果显示，单抗1D7 和2B6均能特异性结合一条分子量116 kD病毒多肽；应用免疫电镜技术定位单抗识别的抗原决定簇，结果发现胶体金颗粒集中吸附在病毒粒子衣壳周围，且背景清洁，无散在的金颗粒或其他污染物。实验结果说明分子量约为116 kD的蛋白多肽为LCDV病毒衣壳蛋白，且具有线性抗原决定簇。     

Apparent digestibility coefficients of nutrients in brewer's and rendered animal by-products for rainbow trout (Oncorhynchus mykiss (Walbaum))

Two experiments were conducted to measure the apparent digestibility coefficients (ADCs) of nutrients, dry matter, and energy in by‐products of the brewing industry and in selected animal protein ingredients for rainbow trout. In experiment 1, 500 rainbow trout (average body weight 170.8±5.5 g) were stocked in ten 140‐L digestibility tanks with 50 fish per tank and two tanks per diet. Yttrium oxide was used as an inert marker in the diets. The high fibre content of brewer's dried grains (BDG) affected the ADCs of dry matter but not of protein or amino acids. Brewer's dried yeast had a higher protein content than BDG, but ADC values for protein and amino acids were significantly lower. The ADCs of phosphorus were similar among brewer's dried products. The BDG high‐protein, fraction had marginally higher ADC values for dry matter, protein and amino acids than regular BDG. Conditions in experiment 2 were similar to those in experiment 1. ADC values for spray‐dried porcine plasma were over 98% for dry matter, crude protein, crude fat, and gross energy. ADC values for spent hen meal were higher than those of poultry by‐product meal or feather meal, with the exception of gross energy. However, spent hen meal was unpalatable. The ADCs in these ingredients were variable, and this variability must be taken into account when these ingredients are formulated into feeds for fish.     

罗氏沼虾白斑综合征病毒囊膜蛋白VP28基因的克隆及分析

根据已公布的罗氏沼虾白斑综合征病毒(WSSV)囊膜蛋白VP28基因序列设计一对特异性引物,从疑似患白斑病毒病的罗氏沼虾(Macrobrachium rosenbergii)中提取总DNA,并以此为模板,经PCR扩增、克隆并测序后将该片段通过GenBank比对,证实为WSSV的VP28基因;与20个已公布的WSSV VP28进行同源性比较,结果显示:从中国对虾、斑节对虾、南美白对虾、日本对虾、波纹龙虾提取的病毒株聚为一类,印度对虾WSSV VP28为另一类,罗氏沼虾WSSV VP28又单独为一类。根据测序结果推测VP28蛋白的二级结构在氨基酸的7～29区间可能为跨膜螺旋区,且该区域高度保守。     

施氮量对津原E28产量和品质的影响

以津原E28为供试品种,研究不同氮肥施用量对该品种水稻产量和稻米品质的影响。结果表明:随着施氮量的增加,水稻产量增加,结实率降低,粒长、宽、厚降低,但当施氮量达到240 kg/hm2以后,各处理组差异不显著;随着施氮量的增加,稻米蛋白质含量显著增加,食味值下降,直链淀粉含量、碘蓝值和透过率变化各处理间差异不显著;对淀粉RVA图谱分析显示,随着施氮量的增加,最高粘度、热浆粘度、冷胶粘度均逐渐下降,且差异显著,崩解值和消减值也逐渐下降,但差异不显著。     

番茄 SlMAPK7基因的亚细胞定位与组织表达特性

分离番茄 SlMA PK7基因,利用实时荧光定量反转录聚合酶链反应技术分析在番茄不同组织和花发育不同时期 SlMA PK7的表达特性,发现该基因在雄蕊的表达量明显高于其他组织,在长度4.6～6.5 mm 的花蕾中表达量最高;通过构建黄色荧光蛋白融合表达载体,利用基因枪介导洋葱内表皮细胞的瞬时表达,发现SlMA PK7基因表达蛋白定位在细胞核和细胞膜中;为进一步研究 SlMA PK7的表达特性,分离克隆了SlMA PK7基因的启动子序列,利用 PLACE 和 PlantCARE 软件预测出其含有多种典型的 SlMA PK 启动子顺式作用元件;通过瞬时表达分析该启动子活性,经农杆菌介导转化拟南芥,GUS(β‐glucuronidase ,β‐葡萄糖苷酶)组织化学染色发现,在幼苗期 SlMA PK7主要集中在顶端分生组织和根尖分生组织中表达,在成年植株中则集中在花器官中表达.以上结果表明,SlMA PK7可能在细胞核和细胞膜中参与番茄多种信号的传导,并可能在花器官的发育过程中行使功能.     

辣木

辣木源自印度和非洲,20世纪70年代引入中国云南、海南和广西等地。由于它富含钙质、植物蛋白、重要矿物质、维生素和重要氨基酸等,而受到人们广泛关注。本文研究辣木的起源、植物学、产量、栽培技术、新种质和各种营养物质等,论述其对人体的作用、营养价值、相关疾病的防治及可能的功效等。