鸡肾型传染性支气管炎病毒的分离及鉴定

本试验从天津某鸡场、呼和浩特市两个鸡场发病鸡群分离到３个肾型ＩＢＶ毒株，分别命名为Ｔ、Ｈ、Ｗ株，并对其培养特性、形态特性、血凝性、致病性、对新城疫病毒的干扰性等方面进行研究。结果表明，３个毒株很快适应于鸡胚，引起鸡胚出血、萎缩、绒毛尿囊膜增厚；３个毒株也适应于鸡胚肾、肺细胞，适应性有差异；病毒增殖后制负染样品，在电镜下观察，可看到直径约１００ｎｍ左右，病毒囊膜外有疏松刺突的冠状病毒。用接毒的肾、肺细胞制成超薄切片后电镜下观察，可看到胞浆内的典型的ＩＢＶ；分离株对鸡的红细胞无凝集性，但用１％胰酶处理后表现不同程度的血凝性；３个分离株均能抑制鸡新城疫病毒Ｂ＿１株在鸡胚中繁殖；分离株回归４２日龄雏鸡后从第３天开始发病，发病率为１００％，病死率为６０－９０％。     

Changes in trypsin and chymotrypsin inhibitory activity on soaking of redgram (Cajanus cajan L.)

Changes in trypsin and chymotrypsin inhibitory activity of redgram seeds on soaking in distilled water, different salt solutions and mixed salt solution were investigated. Reduction in trypsin and chymotrypsin inhibitory activity was observed on soaking in salt solutions in comparison to soaking in distilled water. Maximum loss of trypsin and chymotrypsin inibitory activity was observed on soaking the seeds in mixed salt solution.     

荞麦芽菜营养成分分析评价

 对甜荞(FagoFyrum esculentum)‘榆荞1号’和苦荞(F．tanaricum)‘榆6-21’籽粒萌发过程中胰蛋白酶抑制剂活性及荞麦芽的营养成分进行分析评价。结果表明：荞麦籽粒氨基酸均衡，但籽粒中含有大量胰蛋白酶抑制剂。萌发10 d后，荞麦芽中胰蛋白酶抑制剂活性消失或仅存痕量。利用氨基酸比值系数法评价显示荞麦芽菜的氨基酸较籽粒更为均衡。芽苗中芦丁含量较籽粒增加4～6倍，芽苗中含有丰富的维生素及有机酸。萌发可提高荞麦的营养保健价值。     

雏番鸭胰腺和肠道消化酶活性变化规律研究

本试验以 0～ 3周龄雏番鸭为研究对象 ,分别测定 0 ,1,4 ,7,10 ,14 ,17和 2 1日龄雏番鸭胰腺和肠道中脂肪酶、淀粉酶、胰蛋白酶和总蛋白酶活性的变化。结果表明 :在胰腺中脂肪酶、淀粉酶、胰蛋白酶和总蛋白酶的活性分别在 4 ,14 ,10和 17日龄达到峰值 ;在肠道中 ,脂肪酶、淀粉酶、胰蛋白酶和总蛋白酶的活性分别在 10 ,14 ,17和 14日龄达到峰值。从消化酶的发育规律显示 10～ 17日龄是番鸭消化酶发育的关键时期     

Nutritional studies on rats and fish (carp Cyprinus carpio) fed diets containing unheated and heated Jatropha curcas meal of a non-toxic provenance

Unheated and heated (121 ^°C, 66% moisture; 15, 30 and 45 min) Jatropha meals of non-toxic provenance from Veracruz state in Mexico were evaluated using rats and fish. With rats, the weight gain was highest for the casein diet followed by heated (30 min; only this treatment was studied using rats) and unheated Jatropha meal containing diets. The protein efficiency ratio (PER) for unheated and heated Jatropha meal containing diets was 37 and 86%, respectively, of the casein diet. On the other hand, the body weight gain, PER and feed conversion ratio of fish were statistically similar for unheated and heated (15, 30 and 45 min) Jatropha meal containing diets fed for a period of 35 days. Although these parameters were statistically similar for the unheated and heated Jatropha meal containing diets, the body weight gain, PER and protein productive value were highest and the feed conversion ratio lowest with 15 min heated Jatropha meal, suggesting that the heat treatment for 15 min is optimal for the meal. Trypsin inhibitor and lectin activities decreased drastically (>83 and 99%, respectively) after 30 and 45 min of heat treatment and after 15 min, the residual lectin activity was negligible and the residual trypsin inhibitor activity was 34%. These results, together with the nutritional parameters investigated, imply that Jatropha trypsin inhibitors and lectins do not have any adverse effects on carp at least up to 35 days of feeding. The nutritional value of Jatropha meal of the non-toxic provenance is high, and potential exists for its incorporation into the diets of monogastrics, fish and possibly humans.     

Nutritive Evaluation of Lysine- and Methionine-Supplemented Raw Vs Heat-Processed Soybean to Replace Fishmeal as a Dietary Protein Source for Grey Mullet,Mugil cephalus,and Milkfish,Chanos chanos

Two experiments were conducted to study the effect of methionine- and lysine-supplemented raw and hydrothermically processed full-fat soybean as a dietary protein source on growth performance, digestibility, and digestive enzyme activity in grey mullet, Mugil cephalus (mean BW 0.55 g), and milkfish, Chanos chanos (mean BW 3.83 g). Eight isocaloric (gross energy about 18.27 kj g^?1) and isonitrogenous (crude protein about 40%) diets (1–4 = raw soybean based; 5–8 = processed full-fat soybean based) were formulated. A fishmeal-based diet was used as the reference/control diet. Growth performance, nutrient retention, feed conversion ratio (FCR), and protein digestibility in fishes correlated well with the trypsin inhibitor activity levels of the diets. Carcass phosphorous levels were significantly (P < 0.05) higher in fish fed the fishmeal control diet. Irrespective of the fish species, significantly (P < 0.05) lower levels of total ammonia excretion and reactive phosphate production (mg kg^?1 BW d^?1) were recorded where the fish were fed processed full-fat soybean diets compared with the fish fed fishmeal or raw soybean diets. Among these diets, the best growth performance and the lowest levels of metabolic waste were obtained in fishes fed the methionine- and lysine-supplemented processed soybean-based diets containing no fishmeal.     

日本野生大豆中的一个Kunitz型胰蛋白酶抑制剂变异的纯化与活性测定

大豆Ｋｕｎｉｔｚ型胰蛋白抑制剂现已报告有６个电泳形态,Ｔｉａ,Ｔｉｂ,Ｔｉｃ,Ｔｉａ－ｓ,Ｔｉｂ－ｆ一一个最慢的电泳移动形态。Ｔｉａ,Ｔｉｂ,Ｔｉｃ的活性已被报道。Ｔｉａ和Ｔｉｃ有相似的活性,Ｔｉｂ的活性低于前两者。本文使用ＤＥＡＥ－ｃｅｌｌｕｌｏｓｅ层析化纯化了Ｔｉａ和Ｔｉａ－ｓ蛋白和测定比较了这两个形态的活性。     

Digestive efficiency,free amino acid pools and quality of growth performance in Atlantic salmon (<Emphasis Type="Italic">Salmo salar</Emphasis> L.) affected by light regimes and vaccine types

This study comprised the results of three different seawater trials using unique combination of techniques to study protease digestive efficiency and growth performance quality to illustrate the effects of light regimes and vaccine types in Atlantic salmon (Salmo salar L.). Fish with higher growth had higher trypsin (T) and chymotrypsin (C) specific activities with higher T/C ratio or slope T/C ratio [calculated from the regression between trypsin (y) and chymotrypsin (x) specific activities] in the pyloric caeca. The T/C ratios indicated fish growth rates over a period of 1–2 months, while the slope T/C ratios indicated fish growth rates at sampling. Adaptation period for adjustment to the new environment of continuous light was 70 days, indicated by the differences in trypsin specific activities and the crossing of slope T/C ratio regressions following with the changes in growth rate directions between the control and the treated group. Vaccine types affected fish vertebral growth, and additional continuous light enhanced the impact of vaccines on fish growth during springtime, indicated by differences in slope T/C ratios. Continuous light stimulated fish growth during winter to spring, when the natural day length was short, without significantly changing white muscle and oocyte qualities in the fish of about 500 g, except for significantly increased white muscle RNA concentration. Continuous light also reduced fish growth rate later during summer, when the natural day length was long, by precedently decreasing the T/C ratio in late spring. Interestingly, plasma levels of free lysine related to tryptic digestion were correlated with trypsin specific activity levels. Continuous light caused higher levels of most free amino acids (FAA) involved in nitrogen metabolism, higher incorporation of essential FAA for protein synthesis, and higher protein turnover rate (free hydroxyproline levels) in both plasma and white muscle. However, continuous light did not affect higher protein content, intracellular buffering capacity and RNA levels in the white muscle of the fish of about 1 kg, probably due to limitation of FAA available for protein synthesis. It is therefore suggested that enhancing fish growth by continuous light stimulation should be accompanied by increasing availability or content of dietary protein (and probably minerals), which in turn would improve the quality of fish growth performance through increasing fillet protein concentration, strengthening vertebral growth, and delaying oocyte development.     

大豆中胰蛋白酶抑制剂的钝化方法研究

[目的]对大豆中胰蛋白酶抑制剂进行钝化处理,降低其活性,提高大豆饲料的营养价值。[方法]采用正交试验设计对大豆中胰蛋白酶抑制剂的化学钝化法（亚硫酸钠法）和物理钝化法（微波法和超声波法）进行比较,确定最优钝化工艺条件。[结果]大豆中胰蛋白酶抑制剂的化学法钝化最优工艺条件为：Na2SO3浓度为0.03 mol/L,温度75℃,钝化时间60 min;物理微波法钝化最优工艺条件为：微波功率240 W,时间90 s,粉碎度为过60目筛;物理超声波钝化法最优工艺条件为：加水量30 ml,时间30 min,粉碎度为过60目筛。[结论]3种钝化方法处理后,大豆中胰蛋白酶抑制剂活性均明显降低。     

黑豆胰蛋白酶抑制剂性质分析及高温对其消化特性的影响

胰蛋白酶抑制剂(trypsin inhibitor, TI)在食品科学和生物技术中具有重要的研究价值。为探讨黑豆胰蛋白酶抑制剂(black soybean trypsin inhibitor, BSTI)的性质及胃肠液消化特性,本研究通过脱脂、热处理、硫酸铵盐析以及阴离子柱层析等方法,从黑豆中纯化得到BSTI。SDS-PAGE显示BSTI呈单一条带,相对分子质量约为21 kDa。在60℃以下与pH2~11的范围内,BSTI呈现较高稳定性。当BSTI与胰蛋白酶的摩尔比达到1时,胰蛋白酶的活力被抑制在15%以下。抑制动力学结果表明,BSTI对胰蛋白酶的抑制属非竞争性抑制,其抑制常数Ki=0.24 nmol·L^-1。圆二色谱分析发现,在常温下BSTI的二级结构为:β-折叠43.4%,无规则卷曲29.0%,β-转角21.2%,α-螺旋8.1%。BSTI的变性温度为61±0.9℃。BSTI在模拟胃肠液消化过程中表现出很强的抗酶解作用,但经121℃热处理30 min后,其抗酶解作用显著降低,易被胃蛋白酶、胰蛋白酶和胰凝乳蛋白酶等主要消化酶消化。