植酸酶和非淀粉多糖酶对鲈鱼生长和消化酶活性的影响

以初始体重为(6.26 ± 0.10)g鲈鱼(Lateolabrax japonicus Cuvier)为研究对象,探讨饲料中添加植酸酶（PY）和非淀粉多糖酶（WX和VP）（WX为木聚糖酶和葡聚糖酶的复合酶制剂,VP为纤维素酶、半纤维素酶、葡聚糖酶和果胶酶的复合酶制剂）对鲈鱼生长、体组成以及胃和肠道消化酶活性的影响。以含36.1%鱼粉和18.0%复合蛋白(豆粕：肉骨粉：花生粕：菜籽粕 = 4：3：2：1并添加赖氨酸、蛋氨酸和异亮氨酸以模拟鱼粉必需氨基酸含量)的饲料为基础饲料(Diet 1),分别向每千克基础饲料中添加200 mg PY (Diet 2)和400 mg VP + 800 mg WX (Diet 3),配制出3种等氮(粗蛋白43%)等能(20 kJ/g)的实验饲料。实验在1.5 m× 1.5 m × 2.0 m的浮式海水网箱中进行,每个处理设3个重复,每个重复放养60尾鲈鱼。 每天饱食投喂2次(06：00和18：00)。实验期间水温为27.5－29.5 ℃, 盐度为25‰－28‰,溶解氧大于7 mg / L。实验结果表明饲料中添加外源酶对鲈鱼的成活率无显著影响（92%－95%）,但却显著提高了鲈鱼的增重百分率（从859.3%提高到947.2%和905.2%）和特定生长率（从4.0提高到4.2和4.1） (p<0.01)。与基础饲料组相比,饲料中添加非淀粉多糖酶对鲈鱼鱼体水分、粗蛋白、粗脂肪、灰分以及身体总能均无显著影响;饲料中添加植酸酶对鲈鱼鱼体水分、粗脂肪含量以及身体总能也无显著影响,但却显著提高了鱼体的粗蛋白和灰分含量（p<0.05）。饲料中添加植酸酶和非淀粉多糖酶后,鲈鱼胃和肠道消化酶均有上升趋势。饲料中添加植酸酶对鲈鱼胃和肠道中的脂肪酶和淀粉酶的活性无显著影响,但是显著提高了其胃和肠道中蛋白酶的活性（分别从0.74 U / mg提高到1.02 U / mg和1.09 U / mg提高到1.71 U / mg）(p<0.01)。而饲料中添加非淀粉多糖酶对鲈鱼胃和肠道中的蛋白酶和脂肪酶活性无显著影响,但显著提高了其胃和肠道中淀粉酶的活性（分别从0.05 U / mg提高到0.16 U / mg和0.12 U / mg提高到0.21 U / mg）(p<0.01)。     

摄食水平和食物种类对金鱼生长及氮、磷排泄的影响

本文报道了金鱼的生长率、氨排泄率及磷酸盐排泄率的两个实验的结果。实验A用牛肉作饵料,实验B用配合饲料作饵料。每一实验分6个摄食水平。特定生长率(SGR)与摄食率(R)的关系为:SGR=a十bln(R+1)。实验中两种食物对上式的系数无显著影响。氨排泄率NE与氮摄取率NI的关系为:NE=a+bNI。实验中两种食物对上式的‘b’值无显著影响,但两个实验得出的‘a’值有显著差异。磷酸盐排泄率(PE)与磷摄取率(PI)的关系为:PE=a+bPI。实验中两种食物对上式中的‘b’值无显著影响,但得出的‘a’值有显著差异。若不考虑食物种类的影响,而将两实验数据合并,氮、磷摄取率可分别解释氮、磷排泄率变异的98％和75.7％。     

饥饿状态下草鱼的代谢率和氮排泄率及其与体重的关系

在饥饿条件下,鱼的能量消耗主要有两方面,一是代谢,另一是含氮化合物的排泄。这两个指标的测定,对于预测饥饿鱼的能量收支及生长有很大意义。本项研究利用饥饿实验,测定了30℃下饥饿草鱼的代谢率、氮排泄率与体重的关系。     

不同添加方式植酸酶处理豆粕对牙鲆生长和饲料利用率的影响

以初始平均体重(2.02±0.02)g的牙鲆(Paralichthys olivaceus)为实验对象,进行为期70d的摄食生长实验,研究不同添加方式的植酸酶对牙鲆生长和饲料利用的影响。在5000.0g豆粕中添加2.5g植酸酶,然后用产朊假丝酵母(Candidautilis)进行发酵预处理,得到植酸酶预处理豆粕。共制作4种等氮等能(粗蛋白49.7%、总能20.9kJ/g)饲料,对照饲料主要以鱼粉为蛋白源;在对照饲料的基础上,用豆粕蛋白替代45%的鱼粉蛋白配制成豆粕组饲料;在每千克豆粕组饲料中添加1000IU植酸酶,配制成植酸酶组饲料;用植酸酶预处理豆粕蛋白替代45%的鱼粉蛋白配制成植酸酶预处理豆粕组饲料。结果表明,与对照组相比较,用豆粕蛋白替代饲料中45%的鱼粉蛋白,若不添加植酸酶则显著降低牙鲆的特定生长率(P0.01)、饲料效率、蛋白质效率和氮贮积率(P0.05);直接添加植酸酶组、植酸酶预处理豆粕组牙鲆的特定生长率、饲料效率、蛋白质效率和氮贮积率与鱼粉对照组相比较没有出现显著差异(P0.05);与不添加植酸酶的豆粕组相比较,在含豆粕饲料中添加1000IU/kg饲料的植酸酶显著提高牙鲆的特定生长率(P0.01)、氮贮积率(P0.05)和磷贮积率(P0.01),显著降低氮排放率(P0.05)和磷排放率(P0.01),但饲料效率和蛋白质效率没有显著变化(P0.05);在豆粕中添加植酸酶进行发酵预处理,降低了豆粕中植酸含量,在饲料中添加植酸酶预处理豆粕显著提高牙鲆的特定生长率(P0.01)、饲料效率、蛋白质效率和氮贮积率(P0.05),显著降低氮(P0.05)、磷和钙的排放率(P0.01)。       

谷氨酸和α-酮戊二酸对鳜生长、脱氨及糖代谢的影响

为探究谷氨酸(Glu)和α-酮戊二酸(AKG)对鳜(Siniperca chuatsi)摄食和氨排泄的影响,实验以鳜[初始体重(26.28±0.99) g]为研究材料,将Glu和AKG分别添加到鳜的基础日粮中(添加量2%),进行了60d的养殖实验,前40d等量投喂,后20d饱食投喂。通过设置对照组、Glu组和AKG组,比较了3种不同饲料饲喂下鳜的摄食与氨排泄差异情况。实验结果表明,在等量饲喂期间添加Glu、AKG显著提高鳜生长和降低饵料系数,且在一定程度上降低鳜的体外氨排泄量。在饱食投喂阶段, Glu、AKG组的血液中的葡萄糖含量增加,肝糖原、肌糖原含量降低。两个投喂阶段结果都表明,饲料中添加谷氨酸和α-酮戊二酸能显著促进鳜脑中npy表达并抑制pomc表达,显著提高蛋白质效率比和特定生长率,增加鱼体体重,促进鱼体生长且降低饲料系数。同时,肝脏中gdh表达及肌肉ampd表达均提高,脱氨代谢供能水平升高,最终导致其氨排泄量升高。此外,饲料中添加Glu和AKG可促进肝脏pepck、g6pase、pk和gk基因表达量增加,糖代谢增强,减少蛋白质的分解供能。综上所述,在饲料中添加谷氨酸和α-酮戊...     

无鱼粉低磷饲料中添加中性蛋白酶和植酸酶对建鲤生长及营养物质利用的影响

在无鱼粉低磷饲料中添加中性蛋白酶、中性植酸酶, 考察对建鲤(Cyprinus carpio var. Jian)生长、营养物质消化率和沉积率、血浆生化指标及肠道组织学的影响。配制含鱼粉5%和磷酸二氢钙1.5%的正对照饲料、无鱼粉饲料、无鱼粉低磷饲料(磷酸二氢钙1.0%)和在无鱼粉饲料中添加175 mg/kg蛋白酶, 在无鱼粉低磷饲料中添加175 mg/kg蛋白酶+300 mg/kg植酸酶的5组等蛋白饲料, 饲喂初始体重为(52.5±2.0) g的建鲤10周。结果表明: 对照组具有最高增重率和最低饲料系数(P<0.05), 无鱼粉饲料和无鱼粉低磷饲料组的增重率、蛋白质和磷沉积率、蛋白质和钙消化率均显著下降(P<0.05); 在无鱼粉饲料中添加蛋白酶后, 提高了建鲤增重率13.1%(P<0.05), 达到和对照组基本一致的水平; 显著提高了蛋白质、钙消化率和肠绒毛高度, 降低了饲料系数(P<0.05); 在无鱼粉低磷饲料中添加蛋白酶和植酸酶后, 显著提高了脂肪、蛋白质、磷沉积率和蛋白质、钙、磷消化率(P<0.05), 增加了前肠绒毛长度和隐窝深度(P<0.05), 提高了血浆磷浓度(P<0.05)。以上结果表明, 在全植物性蛋白饲料中添加蛋白酶, 在全植物蛋白的低磷饲料中同时添加蛋白酶和植酸酶可以促进建鲤生长, 提高对营养物质的消化率和沉积率, 促进肠道生长发育。     

摄食水平对中华鳖稚鳖生长、氮排泄和能量收支的影响

在 30℃水温下进行摄食 -生长实验 (实验周期为 5 6d) ,设饥饿、1%、2 %、4 %和饱食 5个摄食水平 ,研究了中华鳖稚鳖 (39 5 4— 4 4 2 2g)的生长和能量收支。结果表明 ,中华鳖稚鳖的特定生长率随摄食水平的增加 ,其湿重、干物质、蛋白质和能量的特定生长率均呈二次曲线增加 ,其中干物质的特定生长率 (SGRdr)与摄食率 (Rl)的关系式为 :SGRdr=- 1 8799 1 0 795Rl- 0 0 832Rl2 (r=0 90 6 ,n =2 5 ,P <0 0 1) ;除干物质转化效率外 ,湿重、蛋白质和能量的转化效率在 2 %组均达到最大 ,分别为 36 31%、2 1 4 7%和 2 8 10 % ;除能量转化效率外 ,4 %组湿重、干物质和蛋白质的转化效率与最大值均无显著差异 ;摄食水平对中华鳖稚鳖总氮排泄率、氨氮排泄率、尿素氮排泄率以及氨氮占总氮排泄率的比例均有显著影响 (P <0 0 1) ,除氨氮占总氮比例外其他指标均随摄食水平的增加而增加 ,氨氮比例在饥饿组最高为 5 5 83% ,由饥饿到饱食其变化范围是 4 4 5 0 %— 5 5 83% ;总氮排泄率、氨态氮排泄率和尿素氮排泄率的变动范围分别是 19 81%— 6 5 87%、9 4 4 %— 36 31%和 8 2 4 %— 2 9 5 6 % ,回归分析表明 ,幼鳖的总氮排泄率 (μmol/g·d) (G N)、氨氮排泄率 (μmol/g·d) (NH3 N)及尿素氮排泄率 (μmol/g·     

鲢、鳙在东湖生态系统的氮、磷循环中的作用

我们研究了鲢、鳙在停食状况下氮、磷的排泄量及在有鱼及无鱼的水环境中鱼类及微囊藻的氮、磷释放率。结合有关参数进行换算,从量的方面评价了鲢、鳙在东湖生态系统物质循环中所起作用:①鲢、鳙摄食过程加速了水体氮、磷释放进程(有鱼水体氮、磷释放率分别为无鱼水体的1.88和1.41倍),但其释放量(粪便的氮、磷释放量分别为水体氮、磷总含量的11.45％和3.4％)不足以左右东湖水体初级生产量的变动;②鲢、鳙摄食过程一方面提高了对初级生产量的利用率,而另一方面却通过鱼体积贮从水体中移出大量氮(52.20吨)、磷(11.36吨),分别占水体浮游物总氮、磷的3.01％和5.28％;③鲢、鳙大量摄食浮游动物,降低了被摄食种群的密度,缩短被摄食种群生物量周转期(1982年被摄食种群的生产量为1981年的1.05倍,鲢、鳙放养量为1981年的7倍;这两年鱼摄食量分别占其被摄食种群产量的31.73％及0.63％,被摄食种群的ρ/B系数分别为67.92及48.01);这样水体中浮游动物产量的相对稳定,也就促使浮游植物产量相对平衡。     

饲料中铜、钙水平对大黄鱼幼鱼生长、抗氧化酶及脂代谢酶活性的影响

为研究钙对摄食高铜饲料的大黄鱼幼鱼生长性能、抗氧化酶类及脂代谢酶类活性的影响,研究采用22双因子实验设计,配制了4组实验饲料,共包含2个铜水平(4和24 mg/kg)和2个钙水平(0.5%和3%),分别命名为: -Cu-Ca、+Cu-Ca、-Cu+Ca和+Cu+Ca,饲喂大黄鱼幼鱼[(4.050.31) g]10周,每个处理组设置3个重复。结果表明,高铜组(+Cu-Ca和+Cu+Ca)实验鱼的存活率、终末体质量和增重率显著低于低铜组(-Cu-Ca和-Cu+Ca)(P0.05); 高铜组实验鱼肝脏和肌肉中的铜含量显著高于低铜组,而高钙组(-Cu+Ca和+Cu+Ca)实验鱼肌肉中的铜含量却显著低于低钙组(-Cu-Ca和+Cu-Ca)(P0.05); 高铜组实验鱼肝脏中的糖原含量显著低于低铜组(P0.05); 实验鱼肝脏中的超氧化物歧化酶、过氧化物酶、谷胱甘肽过氧化物酶、6-磷酸葡糖酸脱氢酶、异柠檬酸脱氢酶和脂肪酸合成酶活性,高铜组显著低于低铜组,而高钙组却显著高于低钙组,但硫代巴比妥酸反应物含量和脂蛋白脂肪酶活性正好相反(P0.05); 饲料中铜和钙的交互作用显著影响了实验鱼肌肉中的铜含量、硫代巴比妥酸反应物含量、6-磷酸葡糖酸脱氢酶、脂肪酸合成酶和脂蛋白脂肪酶活性(P0.05)。研究表明,钙能够缓解摄食高铜饲料对大黄鱼幼鱼造成的伤害。     

三种鱼的磷排泄及其在微型生态系统磷再循环中的作用

在考查罗非鱼或鲢、鳙下行影响的微型生态系统实验后期 ,对三种鱼的特定正磷酸盐 (PO4 P)排泄率进行了测定 ,并且估算了系统中实验鱼的PO4 P排泄率。结果表明 ,在个体大小相同的情况下 ,罗非鱼的特定PO4 P排泄率明显地高于链、鳙 ,似乎同它们的食物含磷量无关而由其体组织含磷量所决定 ;放养罗非鱼的系统中鱼的PO4 P排泄率比放养链、鳙的系统平均高 2倍多 ,其磷排泄对浮游植物的PO4 P供给率分别为 10 0 %— 15 8%和 6 1%—7 5 %。根据有鱼系统中PO4 P的供求关系和实验结束时磷分布的观测结果推断 ,沉积物的磷释放是系统中磷再生的主要途径 ,而实验鱼调节系统磷再循环的主要机制是排粪。     

SYMMETRY AND DEVELOPMENT OF BUTOMUS UMBELLATUS (BUTOMACEAE) AND LIMNOCHARIS FLAVA (LIMNOCHARITACEAE)

The prostrate rhizome of Butomus umbellatus produces branch primordia of two sorts, inflorescence primordia and nonprecocious vegetative lateral buds. The inflorescence primordia form precociously by the bifurcation of the apical meristem of the rhizome, whereas the non-precocious vegetative buds are formed away from the apical meristem. The rhizome normally produces a branch in the axial of each foliage leaf. However, it is unclear whether the rhizome is a monopodial or a sympodial structure. Lateral buds are produced on the inflorescence of B. umbellatus either by the bifurcation or trifurcation of apical meristems. The inflorescence consists of monochasial units as well as units of greater complexity, and certain of the flower buds lack subtending bracts. The upright vegetative axis of Limnocharis flava has sympodial growth and produces evicted branch primordia solely by meristematic bifurcation. Only certain leaves of the axis are associated with evicted branch primordia and each such primordium gives rise to an inflorescence. The flowers of L. flava are borne in a cincinnus and, although the inflorescence is simpler than that of Butomus umbellatus, the two inflorescences appear to conform to a fundamental body plan. The ultimate bud on the inflorescence of Limnocharis flava always forms a vegetative shoot, and the inflorescence may also produce supernumerary vegetative buds. Butomus umbellatus and Limnocharis flava exhibit a high degree of mirror image symmetry.     

COPPER SORPTION AND RELEASE BY CYCLOTELLA MENEGHINIANA (BACILLARIOPHYCEAE) AND CHLAMYDOMONAS REINHARDTII (CHLOROPHYCEAE)1

Initial Cu⁺⁺ sorption by Cyclotella meneghiniana Kütz. (Cu⁺⁺-sensitive) and Chlamydomonas reinhardtii Dangeard (Cu⁺⁺-resistant) was rapid in the first 5 min of Cu⁺⁺ incubation with little sorption after 2 h. On a cell to cell basis, Cyclotella sorbed ca. five times more Cu⁺⁺ from the medium than Chlamydomonas. In MBL medium with EDTA Cyclotella and Chlamydomonas cells sorbed 21.0 and 4.41 nM Cu⁺⁺/10⁶ cells respectively in 6 h with 0.3 mg Cu⁺⁺/l in the medium. Proportionally similar quantities of Cu⁺⁺ were sorbed when the cells were Cu⁺⁺ incubated in MBL + citrate or filtered lake water. Cleaned cell walls of Cyclotella sorbed little Cu⁺⁺ (1.7 nM/10⁶ cells) as compared to living cells (17.5 nM Cu⁺⁺/10⁶ cells) in 3 h. Therefore, in living Cyclotella most of the Cu⁺⁺ taken up must be absorbed by the protoplasm or perhaps by the organic layer surrounding the silica wall. Cleaned cell walls of Chlamydomonas sorbed 3.5 nM Cu⁺⁺/10⁶ cells and living Chlamydomonas cells sorbed 2.6 nM Cu⁺⁺/10⁶ cells. This indicates that most of the Cu⁺⁺ sorbed by Chlamydomonas cells remained bound to the cell wall and probably did not readily enter into the protoplasm: When placed in Cu⁺⁺ free medium after Cu⁺⁺ incubation, Cyclotella and Chlamydomonas cells released 46 and 59% respectively of the Cu⁺⁺ sorbed.     

AUTOTROPHIC GROWTH AND PHOTOACCLIMATION IN KARLODINIUM MICRUM (DINOPHYCEAE) AND STOREATULA MAJOR (CRYPTOPHYCEAE)1

We compared autotrophic growth of the dinoflagellate Karlodinium micrum (Leadbeater et Dodge) and the cryptophyte Storeatula major (Butcher ex Hill) at a range of growth irradiances (E_g). Our goal was to determine the physiological bases for differences in growth–irradiance relationships between these species. Maximum autotrophic growth rates of K. micrum and S. major were 0.5 and 1.5 div.·d^?1, respectively. Growth rates were positively correlated with C‐specific photosynthetic performance (PP^C, g C·g C^?1·h^?1) (r²=0.72). Cultures were grouped as light‐limited (LL) and high‐light (HL) treatments to allow interspecific comparisons of physiological properties that underlie the growth–irradiance relationships. Interspecific differences in the C‐specific light absorption rate (E_a^C, mol photons·g C^?1·h^?1) were observed only among HL acclimated cultures, and the realized quantum yield of C fixation (φ_C(real.), mol C·mol photons^?1) did not differ significantly between species in either LL or HL treatments. The proportion of fixed C that was incorporated into new biomass was lower in K. micrum than S. major at each E_g, reflecting lower growth efficiency in K. micrum. Photoacclimation to HL in K. micrum involved a significant loss of cellular photosynthetic capacity (P_max^cell), whereas in S. major, P_max^cell was significantly higher in HL acclimated cells. We conclude that growth rate differences between K. micrum and S. major under LL conditions relate primarily to cell metabolism processes (i.e. growth efficiency) and that reduced chloroplast function, reflected in PP^C and photosynthesis–irradiance curve acclimation in K. micrum, is also important under HL conditions.     

SENSORY PROFILING AND PRODUCT POSITIONING OF ROASTED AND GROUND (BREW) COFFEE AND SOLUBLE (INSTANT) COFFEE WITH AND WITHOUT ADDED FLAVOR

Coffee powders available commercially are of different qualities. The quality variations may be due to inherent quality of coffee beans, storage time and packaging materials used. Sensory profiles of brewed and soluble coffees were studied through profiling. Canonical discriminant analysis (CDA) used for positioning the different coffee samples showed that freshly made coffee from plantation arabica (PA), Pea berry (PB), PA with chicory (PAC), PB with chicory (PBC) and their blends viz. PA + PB and PAC + PBC occupied the quadrant where coffee aroma and overall quality rated higher. Other roasted & ground (R&G) coffee (market) samples were positioned where oily, fermented, musty, stale and caramelized notes dominated. In case of soluble coffee, the flavored coffee procured from the western market (S3, S6, S9 and S8) dominated the quadrant where other added flavor and oily notes dominated. The typical soluble (instant) coffee without any added flavor S10, S12 and S13 occupied another quadrant. The soluble coffee powder with spice incorporation took a separate quadrant where other added flavor and bitter taste dominated. The dominant quality attributes for the groups are different and are discussed in relation to the directional vectors.     

美国白蛾与其相似种—奇特望灯蛾在形态学和生物学上的区别(鳞翅目,灯蛾科)

奇特望灯蛾与大害虫--美国白蛾侄幼虫形态及危害方式方而都极其相似,其雌成虫与美国白蛾的成虫也很相像,极易引起混淆.并且奇特望灯蛾分布广,容易与美国白蛾的分布区重叠,这对美国白蛾准确及时的预测预报及防治工作造成了一定的干扰.本文就天津蓟县发生的奇特望灯蛾与美国白蛾在成虫、卵、幼虫和蛹的形态以及生活习性等方面进行了比较研究.     

阿司匹林和复方新诺明对大豆种子萌发及活力的影响

 以大豆(Glycine max)种子为材料,浓度的阿斯匹林和复方新诺明水溶液,在(20±1)℃条件下分种24h和12h, 测定大豆种子萌发过程中的各项生理生化指标以及萌发后的各形态指标实验结果表明：阿斯匹林和复方新诺明水溶液浸种都能有效地提高大豆种子的发芽率和活力指数,还能促进大豆根系的生长。其中以62.5mg·L-1的阿斯匹林和0.5mg·L-1的复方新诺明处理后的效果最为显著。阿斯匹林浸种能使大豆萌芽的相对电导率显著降低,使活性氧清除酶的活性有所提高。复方新诺明浸种则使大豆萌芽的蛋白质含量以及氨基酸总量都有显著的提高。     

用反向被动血凝及血凝抑制方法检测流行性出血热病毒抗原和抗体

本文建立了检测流行性出血热病毒(EHFV)液体抗原及抗体的反向被动血凝(RPHA)和血凝抑制(RPHI)方法,RPHA检测EHFV抗原的敏感性与ELISA相近;RPHI检测EHFV抗体与IFA的符合率为97.3％,敏感性略低。