点带石斑鱼幼鱼配合饲料的适宜能量蛋白比

以鱼粉和酪蛋白为蛋白源,添加鱼油、豆油、α-马铃薯淀粉、纤维素以及适量的维生素和矿物质配制成实验饲料,蛋白质质量分数设置41%、47%、53%3个水平,能量设置12 561、14 655、16 748 kJ/kg 3个水平,饲养点带石斑鱼幼鱼59 d后,以增重率、蛋白质效率、饲料系数为评价指标,分析不同能量蛋白比的饲料对点带石斑鱼体内消化酶活性的影响。结果表明:当能量蛋白比分别为31.30、33.50、32.26 kJ/g时,点带石斑鱼增重率、蛋白质效率达到极大值,饲料系数达到极小值;能量蛋白比在31.62～35.54 kJ/g范围内,胃、肠道的蛋白酶、淀粉酶、脂肪酶活性较强。点带石斑鱼幼鱼配合饲料中合适的能量蛋白比为31.62～33.50 kJ/g。     

The aquaculture potential of Tilapia rendalli in relation to its feeding habits and digestive capabilities

Tilapia rendalli is a predominately macrophagous fish. However, it was able to colonise an oligotrophic dam (Flag Boshielo) with limited macrophytes. Therefore, the diet of T. rendalli in this dam was investigated; its stomach contents were examined over 12 months. A size related dietary shift was evident. Juveniles fed mainly on zooplankton while sub-adult and adult fish grazed on both macrophytes and marginal vegetation. T. rendalli’s ability to strive in an environment with limited food resources led to a subsequent study to determine its aquaculture potential. Its growth performance was compared to that of the commonly cultured Oreochromis mossambicus. Juveniles of both species were fed a commercial tilapia diet for 60 days. Specific growth rate and protein efficiency ratio was comparable to that of O. mossambicus (P > 0.05, ANOVA). Feed conversion ratio was significantly higher (P < 0.05) in T. rendalli (1.43) than in O. mossambicus (1.25) indicating a better efficiency in feed utilisation by O. mossambicus. At a physiological level, protease, lipase and cellulase activities did not differ significantly between the two fish species (P > 0.05). Amylase activities were significantly higher (P < 0.05) in T. rendalli than in O. mossambicus. The highest amylase activities were recorded in the proximal intestines as 26.34 and 22.00 μmol/min/mg protein in T. rendalli and O. mossambicus respectively. This may be an indicator that T. rendalli is better equipped to digest plant diets. T. rendalli may be the aquaculture species of choice for emerging fish farmers who cannot afford the highly priced fishmeal as a protein source in fish diets.     

瘤背石磺体腔细胞分类、免疫相关酶特性及初步转录组学分析

瘤背石磺(Onchidium struma)广泛分布于潮间带和潮下带,是海洋生物向陆地生物辐射进化的重要代表,也是环境监测的指示生物.为丰富瘤背石磺的基础免疫学资料,本文研究了瘤背石磺体腔细胞的类别、细胞密度和体腔液免疫相关酶活性,并通过RNA-Seq测序获得体腔细胞转录本,进行生物信息学分析.结果表明,瘤背石磺主要有...     

高温对褐藻羊栖菜逆境生理的影响

分别在27℃和32℃高温条件下培养羊栖菜(Sargassum fusiforme), 以在22℃培养条件下生长的羊栖菜作为对照, 在培养的第0、1、3、5和7天分别取气囊样品, 采用植物生理学试验方法探讨高温胁迫对羊栖菜细胞膜损伤、渗透调节和抗氧化保护的影响。结果表明: 1) 高温胁迫导致羊栖菜细胞的相对电导率提高和丙二醛(MDA)质量摩尔浓度增加, 膜系统受到了损伤, 造成体内离子外渗、细胞膜脂发生过氧化; 2) 细胞内积累了可溶性蛋白、可溶性糖和脯氨酸等渗透调节物质并且胁迫组始终高于对照组, 其中可溶性蛋白在胁迫第7天时达到最大值(11.4μg·mg^-1), 而可溶性糖和脯氨酸均呈现先升高后降低的趋势, 分别在高温培养的第3天和第5天时达到最大值; 3) 受到高温胁迫后, 羊栖菜超氧化物歧化酶(SOD)比活性增强, 而过氧化物酶(POD)和过氧化氢酶(CAT)比活性在高温胁迫过程中呈现下降的趋势, 说明羊栖菜主要通过抗氧化酶SOD比活性增强来降低胁迫对藻体带来的伤害。总之, 羊栖菜对高温胁迫比较敏感, 温度越高, 培养时间越长, 羊栖菜受到的伤害越大。     

复合酶制剂对中国对虾消化率的影响

添加复合酶制剂，可以提高对虾内源酶的活性，增强肝胰脏的消化作用。 对虾饲料中添加１％。复合酶制剂可使对虾总消化率和蛋白质消化率分别提高 ４．８１％和２．４６％。     

从鳕鱼碎肉中提取水解蛋白

用蛋白酶水解法从鳕鱼加工废弃物－鳕鱼碎肉中提取水解蛋白。鳕鱼碎肉经枯草杆菌ＡＳ１．３９８中性蛋白酶２４０ＩＵ／ｍｌ，ｐＨ７．０，５０℃下水解２ｈ；再经黄曲霉ＩＦＦＩ２３４２（蛋白酶活力２０００ＩＵ／ｇ）１．５％（ｗ／ｖ），５０℃，ｐＨ６．０下水解６ｈ以脱苦味。水解液经真空浓缩后喷雾干燥得水解蛋白粉。该制品易溶于水，无苦味，有海鲜味。其氨基酸组成合理，是优良的蛋白质制品。     

海洋无脊椎动物消化酶的研究 Ⅰ、紫贻贝、日本蟳、滨螺消化酶的初步分析及其应用

本文用11种酶底物,测定了紫贻贝、日本蟳和滨螺消化系统的酶活性,并初步研究了这些消化酶的应用。实验表明:1.0％的紫贻贝消化酶在25℃、20分钟内可水解去除鲬鱼受精卵膜。1.0％的该消化酶加入等体0.5％的半纤维素酶和果胶酶,在30℃、60分钟内可制备出大量啤酒酵母原生质体。在同样条件下,1.5—2小时内,可去除大部分三角褐指藻的细胞壁。     

褐藻中活性物质研究概况

对近年来从褐藻中发现的有活性的多糖类、脂类、含氮类、萜类、甾醇类、类胡萝卜素、酶类、激素及其他活性物质进行综述。