皱纹盘鲍内脏酶的酶学性质及褐藻胶裂解酶的分离纯化

采用(NH4)2SO4分段盐析、透析、阴离子(DEAE-52)交换柱层析、SephadexG-200凝胶柱层析等分离纯化技术，通过SDS-PAGE电泳分析了皱纹盘鲍内脏酶的组成，结果表明鲍内脏酶主要含有两种褐藻胶裂解酶Ⅰ, Ⅱ，一种纤维素酶，一种琼脂酶。对酶的酶学性质分析结果表明两种褐藻胶裂解酶Ⅰ, Ⅱ的最适pH分别为8.6, 7.2，最适温度为35 ℃，分子量分别为35.2 ku, 67 ku；两种褐藻胶裂解酶的热稳定性比较差，且易受金属离子影响；纤维素酶的最适pH为5.0，最适温度为40 ℃。并确定了皱纹盘鲍内脏酶分离纯化的方法及参数，为进一步研究鲍内脏复合酶的性能提供了基础参数。图14表3参12 关键词：皱纹盘鲍； 褐藻胶裂解酶； 纤维素酶； 纯化 E-mail：wqk320@dlfu.edu.cn     

不同鲍及其杂交种的营养成分与质构特性

绿盘鲍和西盘鲍作为经全国水产原种和良种审定委员会审定通过的水产新品种，在生长和耐高温性能上表现出显著优势，已在产业上广泛推广养殖，但其营养品质方面的研究尚不完善。本研究以这两个鲍新品种以及西氏鲍、皱纹盘鲍和绿鲍为对象，对其营养成分与质构特性进行了比较分析。结果显示，绿盘鲍的肥满度为(0.76±0.14) g/cm³，相较于其母本提高了35.71%，相较于其父本提高了72.73%；足肌的粗蛋白含量为62.26%±6.62%，相较于其母本提高了9.83%，相较于其父本提高了14.26%，因此在肥满度和粗蛋白含量方面，绿盘鲍具有明显的超亲杂种优势。5种鲍的脂肪酸营养价值为皱纹盘鲍>绿盘鲍>西盘鲍>绿鲍>西氏鲍，可见杂交种的脂肪酸营养具有中亲杂种优势。在质构指标上，西氏鲍的弹性和脆度最高，绿鲍脆度最低，杂交种各项质构指标都未表现出杂种优势。熵权法综合分析结果显示，皱纹盘鲍营养品质最优，绿盘鲍和绿鲍在风味上优于西氏鲍与西盘鲍。本研究结果将为未来鲍的品质育种及产品精深加工与开发提供技术支撑。     

皱纹盘鲍卵的形态与超显微结构↑（*）

本文用扫描电镜和透射电镜观察了皱纹盘鲍成熟未受精卵和受精卵的形态及超显微结构。皱纹盘鲍的成熟卵无卵极标志，卵质中含有线粒体、内质网和高尔基复合体等细胞器，未发现中心粒。皮层中有皮质小泡，受精后发生皮层反应。在鲍的受精卵中，线粒体、高尔基复合体和内质网的数量明显减少。在鲍的成熟卵和受精卵中，均观察到光滑内质网合成脂滴以及脂滴形成卵黄粒的现象     

关于玛瑙鲍的探索与研究

选择皱纹盘鲍（Ｈａｌｉｏｔｉｓ ｄｉｓｃｕｓ ｈａｎｎａｉ）的变异个体－－贝壳为红色的玛瑙鲍（Ａｇａｔｅ Ａｂａｌｏｎｅ）作亲体,进行人工繁殖的培育。发现在性产物排放诱导率、孵化率、幼虫附着率和稚鲍生长等方面,玛瑙鲍与皱纹盘鲍大致相同。但稚鲍对不良环境（如赤潮）的抗性,玛瑙鲍明显强于皱纹盘鲍,３２ｄ存活率,前者为６３．１％,后者为３４．３％。ＬＤＨ电泳图谱显示,玛瑙鲍内脏组织中ＬＤＨ活性较高,而被     

鲍内脏酶的研究及其应用前景

皱纹盘鲍是我国北方海珍品的主要养殖种类，其特殊的生长习性、营养及药用价值说明它的消化能力强，体内具有活性强的酶。近年来，鲍内脏酶的研究越来越为人们所重视，特别是鲍内脏中的褐藻酸酶、纤维素酶、琼脂酶的研究和应用。本文主要研讨鲍内脏酶的组成、制备法及其应用前景。     

海洋经济软体动物肌肉副肌球蛋白分布特性初探

以肌肉组织的蛋白为切入点,探索海洋经济软体类主要可食部位的化学特性与差异,并对软体类副肌球蛋白的分布特点进行初步探索。研究对象为商品活体经济软体类,包括菲律宾蛤仔、毛蚶、脉红螺、皱纹盘鲍及长蛸5个种类。首先,对可食部位化学组成及氨基酸组成进行分析比较,结果显示,5种软体动物间一般化学组成差别不大,肌肉中均含有17种氨基酸,且亮氨酸和赖氨酸含量均较高,氨基酸含量无显著差异。然后,对肌肉组织蛋白组分及各组分含量分布进行分析与比较,SDS-PAGE分析表明,5种软体动物肌肉中均含有肌球蛋白、肌动球蛋白、副肌球蛋白及原肌球蛋白等重要组分;同时在菲律宾蛤仔、毛蚶及皱纹盘鲍的肌肉中含有分子量高于200 ku的未知蛋白聚合物。基于质谱分析鉴定并结合分子量进一步计算,确定该蛋白聚合物为副肌球蛋白聚合体。综上可知,不同软体类肌肉蛋白组分分布的差异主要体现在副肌球蛋白,因此,副肌球蛋白及其聚合体的分布特性值得进一步探索。     

皱纹盘鲍与盘鲍杂交效果分析

从杂种优势的角度对皱纹盘鲍♀与盘鲍♂杂交子一代的经济性状进行分析。结果表明,4月龄杂交鲍子一代(F1)活体重比皱纹盘鲍增加36.87%,软体部干重增加33.21%,总干重增加29.20%,其它性状也显著优于皱纹盘鲍。杂交鲍F1的壳长、壳宽、活体重、软体部干重和总干重等主要性状的变异系数为12.94%~44.51%,其中软体部干重的变异系数最大,壳长的变异系数最小;且杂交鲍各性状的变异系数均大于皱纹盘鲍。杂交鲍子一代的变异有助于定向选择,提高杂交育种的效果。     

皱纹盘鲍性腺多糖体外免疫活性和抗凝血活性的研究

采用MTT法检测皱纹盘鲍性腺多糖对淋巴细胞增殖活性的影响的作用;采用中性红吞噬法检测对小鼠腹腔巨噬细胞吞噬功能的影响;用凝集法测定活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)和凝血酶时间(TT).试验结果表明,皱纹盘鲍性腺粗多糖(CAGP)和性腺多糖组分1(AGP-1)对小鼠淋巴细胞增殖具有促进作用;对小鼠巨噬细胞的吞噬功能也具有促进作用;AGP-1能极显著延长PT、APTT和TT,且呈剂量信赖性.CAGP和AGP-1对免疫细胞的增殖和功能具有一定的促进作用;AGP-1具有明显的抗凝血效果.     

三倍体皱纹盘鲍活体倍性检测

以皱纹盘鲍的血细胞为材料，采用植物血球凝集素(PHA)体外浸泡法，运用正交实验设计，探讨PHA处理时间、PHA浓度、抽血时间对细胞分裂频度的影响。根据正交实验直观分析结果，得出用血细胞直接制备染色体标本进行三倍体皱纹盘鲍活体倍性检测的最优组合：PHA处理时间18h、PHA浓度0．04％，抽血时间22：00-24：00，3因素的主次顺序：PHA处理时间→PHA浓度→抽血时间。并可获得大量图象清晰、长度适中、分散良好的中期分裂相，是皱纹盘鲍活体倍性检测的最佳方法。同时，通过流式细胞仪测定皱纹盘鲍血细胞DNA相对含量进行三倍体皱纹盘鲍活体倍性检测，该方法制样简单，测试速度快。     

近江牡蛎等3种贝类的脂类成分分析

分析3种贝类的脂类成分,以期为贝类的高值化加工利用提供基础数据。采用氯仿甲醇法提取近江牡蛎、波纹巴菲蛤和马氏珠母贝中的脂质成分,分析脂质中的胆固醇和磷脂含量,采用液液萃取技术分离中性脂和极性脂,并用GC-MS分析其脂肪酸组成。研究结果表明,3种贝类的粗脂肪含量基本在1%左右;脂质成分中胆固醇含量在0.07~0.12 mg/g;脂质中磷脂含量在14%~34%,极性脂含量在27%~45%;脂质中EPA和DHA总含量在12%~22%,近江牡蛎和波纹巴菲蛤脂质中EPA含量高于DHA,而马氏珠母贝脂质中DHA含量高于EPA。     

Fatty acids of the lipids of cultured herring

The composition of fatty acids was determined in neutral lipids and phospholipids from cultured herring reared on a diet based on squid muscle. The phospholipids retained the fatty acid pattern characteristic of marine fish. In contrast, the fatty acids of neutral lipids tended to reflect the fatty acid spectrum in the diet, and were very different from the characteristic pattern of herring oils. It was concluded that the cultured herring had little ability to modify dietary fatty acids and that the enzymes of phospholipid metabolism possess considerable specificity for certain fatty acids.     

Relationship between dietary phospholipid classes and neutral lipid absorption in newly-weaned turbot, shape Scophthalmus maximus

A 28-day feeding trial was conducted for comparing the effect of different dietary phospholipid (PL) classes on the growth of post-larval turbot and on the incorporation of dietary neutral lipid fatty acids into their body lipids. Prior to the experiment the turbot were weaned for one week on a PL-free diet. The nine experimental diets were isolipidic and contained an equal amount of highly unsaturated fatty acids in the form of ethyl esters. They differed by their PL content (0, 1 or 2%) and by the PL class composition of the added soybean PL fractions.Compared to the PL-free diet, diets enriched with phosphatidylcholine (PC) resulted in a better growth, a higher triglyceride content (% body dry matter) and increased levels of docosahexaenoic acid (% total fatty acids) in each of the examined body lipid classes (neutral lipid, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol). The effects of the other soybean PL fractions were less explicit than those noted for soybean PC.The results support the idea that dietary PC plays a role in the intestinal absorption of neutral lipid fatty acids. This might, at least partially, explain the superiority of PC for enhancing growth. Abbreviations: DHA – docosahexaenoic acid (22:6n-3); EPA – eicosapentaenoic acid (20:5n-3); HUFA – highly unsaturated fatty acid; PA – phosphatidic acid; PC – phosphatidylcholine; PE – phosphatidylethanolamine; PI – phosphatidylinositol; PL – phospholipid; PS – phosphatidylserine; PUFA – polyunsaturated fatty acid.     

2种壳色皱纹盘鲍营养成分的比较

对皱纹盘鲍 (HaliotisdiscushannaiIno) 2种壳色个体———红壳个体和绿壳个体的一般营养成分、矿物元素以及脂肪酸的组成和含量进行比较研究。结果表明 ,两者对应组织 (足肌、内脏、生殖腺 )中水分、蛋白质、粗脂肪、灰分的含量基本无差异 ;内脏灰分颜色均为红褐色 ,但足肌灰分颜色明显不同 ,绿壳个体呈灰白色而红壳个体则呈浅砖红色。矿物元素的分析结果进一步显示 ,足肌中除了Ca之外 ,所测元素的含量均以红壳个体为高 ,其中Fe、Cu、Mn的含量为绿壳个体的2～ 3倍 ;红壳个体贝壳中Mn的含量亦较高 ,约为绿壳个体的 2倍。两者上述对应组织的脂肪酸种类相同 ,含量基本一致。此外 ,粗脂肪、无机元素含量以及脂肪酸的组成和含量在不同组织之间存在较明显的差别     

Influence of dietary polar lipids' quantity and quality on ingestion and assimilation of labelled fatty acids by larval gilthead seabream

Dietary supplementation of phospholipids seems to be extremely important to promote growth and survival in fish larvae. Several studies also suggest the importance of n-3 highly unsaturated fatty acids (HUFA) rich phospholipids to further enhance larval performance. In the present study, four different diets were formulated in order to compare the effect of total dietary polar lipid contents, of soya bean lecithin supplementation and of feeding n-3 HUFA in the form of neutral or polar lipids on ingestion and incorporation of labelled fatty acids in gilthead seabream larvae. These diets were prepared including radiolabelled fatty acids from palmitoyl phosphatidylcholine, glycerol trioleate, free oleic acid (FOA) and free eicosapentaenoic acid (FEPA) and were fed to 25 day-old larvae. The results of these experiments showed that the elevation of the dietary polar lipid levels significantly improved microdiet ingestion, regardless of the origins of the polar lipids. This effect caused an improved incorporation of phosphatidylcholine fatty acids to the larval polar and total lipids (TL) as the dietary polar lipids increased. Nevertheless, a better incorporation of fatty acids from dietary polar lipids in comparison with that of fatty acids from dietary triglycerides into larval lipids was found in gilthead seabream, whereas a better utilization of dietary triglycerides fatty acids than dietary free fatty acids could also be observed. Besides, the presence of n-3 HUFA rich neutral lipids (NL) significanlty increased the absorption efficiency of labelled oleic acid from dietary triglycerides, but the presence of n-3 HUFA rich polar lipids, particularly improved the incorporation of FEPA. This fatty acid was preferentially incorporated into larval polar lipids in comparison with FOA.     

Determination of Fatty Acid Composition and Phospholipid Molecular Species of Large Yellow Croaker (Pseudosciaena crocea) Roe from China

The aim of this study is to investigate the composition of the fatty acids and phospholipids derived from large yellow croaker (Pseudosciaena crocea) roe. The composition of the total lipids and the molecular species of phospholipids were determined by gas chromatography–mass spectroscopy (GC–MS) and high performance liquid chromatography–evaporative light scattering detector (HPLC–ELSD), respectively. The results showed that large yellow croaker roe had high levels of the total lipid (19.6% ± 1.32%, w/w) and phospholipid (61.2% ± 1.22% of the total lipid). The phospholipid was rich in docosahexaenoic acid (31.0% ± 0.19% of the total phospholipids), and the major phospholipid molecular species was phosphatidylcholine (PC, 61.06% ± 0.02% of the total phospholipids, w/w). It was concluded that large yellow croaker roe is expected to be a good resource of phospholipids with a high content of PC.     

Influence of broodstock gilthead seabream (Sparus aurata L.) dietary fatty acids on egg quality and egg fatty acid composition throughout the spawning season

The influence of broodstock dietary lipids on egg quality and egg fatty acid composition throughout the spawning season of gilthead seabream was investigated. For this purpose, the fish were fed for 7 months either a control diet (diet C) or a diet deficient in n−3 highly unsaturated fatty acids (n−3 HUFA) but rich in both oleic (18:1n−9) and linolenic (18:3n−3) acids (diet D). Eggs spawned by both groups of fish were sampled at the beginning, middle and end of the spawning season and the fatty acid composition of their neutral (NL) and polar lipids (PL) determined. In the early season, percentages of fertilized and hatched eggs, relative proportions of NL and PL as well as their fatty acid compositions, were not affected by the lipid composition of the broodstock diet. However, the eggs spawned during the middle and late seasons showed marked differences among the two groups of fish, clearly reflecting the influence of dietary fatty acids. This influence was more evident in the neutral lipid fraction than in the polar lipids. No correlation was found between the number of buoyant eggs and eicosapentaenoic (20:5n−3, EPA), docosahexaenoic (22:6n−3, DHA) fatty acids or total n−3 HUFA contents in egg phospholipids. However, a negative correlation was detected when percentages of fertilized eggs were compared with the levels of 18:1n−9, 18:3n−3 and with the ratio 18:1n−9/n−3 HUFA present in the phospholipids. Our results indicate the importance of maintaining not only the level of n−3 HUFA in egg membrane phospholipids, but also the balance between n−3 HUFA and other fatty acids such as 18:1n−9 and 18:3n−3, in order to obtain a high spawning quality.     

Relation between lipid and fatty acid composition of eggs and larval survival in white pacific shrimp (Penaeus vannamei, Boone, 1931)

In this study, lipid classes and fatty acid composition were determinedin eggs of P. vannamei as a function of survival to zoeaIII stage. Spawns were reared individually to zoea III and grouped, accordingtotheir final survival to this larval stage, into spawns of high and lowsurvival.Eggs of individual spawns were analyzed for lipid and fatty acid composition ofneutral and polar lipids and the results were then grouped according tosurvivalto zoea III. The lipids within each group (high and low survival to zoea III)were pooled for the separation of phospholipids and the analysis of their fattyacid composition.Higher levels of triglycerides, carotenoids, and linoleic (18:2n-6) acid ineggs were associated with improved survival to zoea III. Linoleic acid washigher in spawns from the high survival group in both neutral and polarfractions and in most of the phospholipid classes analyzed. Docosahexanoic acid(DHA) was not related to survival to zoea, probably because its content washighenough (> 15% of total fatty acids) to satisfy embryo and early larvaldevelopment needs. A high content of eicosapentaenoic acid (EPA) was found inphosphatidylethanolamine, lysophosphatidylethanolamine, phosphatidylserine, andphosphatidylinositol compared to other phospholipid classes, suggesting aspecific role of EPA in these lipids. These results describe the specificphospholipid composition of penaeid eggs and could (potentially) be used aspredictive indicators of larval quality for research and production purposes.     

Dietary lipids and temperature interact to influence tissue fatty acid compositions of Atlantic salmon, Salmo salar L., parr

Fatty acid compositions of both the polar phospholipids (PLs) and the non‐polar neutral lipids (NLs) in fish tissues are influenced by dietary fatty acids, and tissue fatty acid compositions also change during thermal acclimation. The interaction between these factors in governing fatty acid compositions has been little studied, even though this may have importance when fish are reared in cold water. An experiment was conducted to investigate the effects of temperature (2 vs. 8°C), dietary oil source (fish oil vs. vegetable oils) and feed fat content (21% vs. 34% fat) on tissue fatty acid compositions of Atlantic salmon parr. The fish were held in fresh water under a 12 h light:12 h dark photoperiod until they doubled in body mass (from ca. 19 to 38 g, which took ca. 2 months at 8°C and ca. 6 months at 2°C), and then the muscle, viscera and carcass PLs and NLs were analysed for fatty acid composition. The ratios of unsaturated to saturated fatty acids (UFA:SFA), and the unsaturation indices (UIs, the number of unsaturated bonds per 100 fatty acid molecules) were calculated for each lipid class (PL, NL) within each tissue (muscle, viscera and carcass). Both dietary fatty acids and temperature influenced the compositions of the tissue lipids, with the dietary effects being most pronounced. The fatty acid composition of the feed oils was strongly reflected in the NLs of all three tissues, and also had a significant influence on the fatty acid profiles of the PLs. The effects of temperature were more marked in the PLs than in the NLs. Exposure to the lower temperature resulted in PLs with higher UFA:SFAs, and this is interpreted as a thermal acclimation response that would contribute to the maintenance of membrane fluidity. The PLs of fish given vegetable oils had higher UFA:SFAs than those of salmon provided with feeds containing fish oil, implying that the cell membranes of the former may have had greater fluidity. By contrast, the PLs of salmon fed with fish oil had higher concentrations of n‐3 highly unsaturated fatty acids, and higher UIs, which may have made them more prone to peroxidative damage. This raises the intriguing possibility that the feeding of vegetable oils may have produced fish that were better able to withstand exposure to low temperature as a result of improved membrane fluidity (implied from the higher UFA:SFAs in these fish), while having membrane PLs that were less susceptible to oxidative damage (implied from the lower UIs).     

Lipid and fatty acid compositions of muscle from farmed and wild adult turbot

The aim of this study was to compare the total lipid, neutral lipid, phospholipid contents, phospholipid class distribution and fatty acid composition of these lipids in muscle of wild and farmed turbot (Scophthalmus maximus) of similar body size. The results showed that muscle of farmed turbot had a higher lipid content than that of wild turbot (1.06% versus 0.64%) because they contained more neutral lipids (0.52% versus 0.24%) and more phospholipids (0.54% versus 0.40%).Distribution of phospholipid classes in muscle of both wild and farmed turbot was similar with 67–70% phosphatidyl choline, 22–25% phosphatidyl ethanolamine and 4.4–5.2% phosphatidyl inositol plus phosphatidyl serine and 2.4–2.9% sphingomyeline.Compared to wild turbot, all of the lipid classes from farmed turbot contained lower proportions of long chain -3 PUFA and 20:4 -6 and conversely higher proportions of 20:1 and 22:1. The ratio between -3 and -6 polyunsatured fatty acids was higher in all the lipid fractions of wild turbot than in those of farmed fish (8.8 versus 4.2 in total lipids, 11.0 versus 3.3 in neutral lipids, 7.9 versus 4.7 in phospholipids). © Rapid Science Ltd. 1998     

南极磷虾粉脂质及脂肪酸组成分析

为分析南极磷虾粉的脂质成分,实验采用薄层层析法分离制备不同脂质组分,通过酸甲酯化衍生结合气相色谱/质谱法对不同脂质的脂肪酸组成进行比较研究.结果显示:①南极磷虾粉中脂质丰富,总脂含量高达11.37％,且以甘油三酯、磷脂和游离脂肪酸为主,胆固醇含量较低;②总脂脂肪酸主要为C16:0、C18:1n-9、C18:1n-7、C20:5n-3和C22:6n-3,且C20:5n-3和C22:6n-3占总脂肪酸含量的30.67％,表明南极磷虾粉在脂质方面具有较高的营养价值和开发潜力.③不同脂质的脂肪酸组成差异显著,胆固醇酯和甘油三酯中饱和脂肪酸和单不饱和脂肪酸含量均显著高于游离脂肪酸和磷脂(P＜0.05);而游离脂肪酸和磷脂富含多不饱和脂肪酸,两者含量分别为48.50％和49.96％,远高于胆固醇酯和甘油三酯的13.11％和24.36％,具有显著差异(P＜0.05).