不饱和脂肪酸对鱼类免疫功能的影响

不饱和脂肪酸是鱼类的必需脂肪酸,作为构成细胞膜磷脂的前体,对鱼类体内的必需脂肪酸组成、鱼类正常生长发育和存活及饵料利用效率起重要作用.从营养免疫学角度综述了饵料中n-3和n-6系列不饱和脂肪酸对鱼类免疫系统和抗应激能力的影响,以及对鱼类免疫调节的作用机制.     

磷脂对仔稚鱼生长发育的影响

<正>饵料磷脂对仔稚鱼的生长发育产生很大的影响:磷脂是细胞膜的重要组成成分,能够提高脂肪的吸收和转运,提高饵料的质量,尤其是适口性并且还能为鱼类提供一些必需的营养素,如胆碱和肌醇[1]。然而不同种类的磷脂对鱼类的影响不尽相同,在考虑其对仔稚鱼的影响时必须考虑磷脂的种类和脂肪酸组成。在研究饵料磷脂对仔稚鱼的影响时非常难区分到底是完整磷脂的作用还是其所含的不同的脂肪酸的作用。本文旨在讨论磷     

磷脂的功能及其在水产养殖中的作用

磷脂具有多重营养作用，作为饲料添加剂已广泛应用于饲料工业，并取得了较好的经济和社会效益。就磷脂的结构和性质、饲用磷脂的种类以及磷脂的功能作用作一介绍，着重阐述了磷脂在水产养殖中的作用，包括在海水鱼类、淡水鱼类和甲壳类养殖中的作用，对磷脂在水产养殖上的开发前景作一展望。     

磷脂在水产动物养殖中的应用

磷脂是存在于动植物体内一种含磷酸的复合脂质。在过去的几十年中，人们研究了在水生甲壳类和鱼类的饵料中添加磷脂的效果，磷脂在鱼虾类营养方面的重要性已经引起了人们的重视。一、磷脂的种类和结构磷脂广泛存在于动植物体内。磷脂是由一分子甘油与两个脂肪酸、一个磷酸和一个氨基醇残基所组成。根据磷脂分子中N／P的比例，常将它分为一氨基磷脂，P∶N＝１∶１（如卵磷脂、脑磷脂）；二氨基磷脂，P∶N＝１∶２（如神经磷脂）；以及不含氮的磷酸酯等三类。磷脂主要包括卵磷脂、脑磷脂、肌醇磷脂、丝氨酸磷脂、糖脂、固醇脂和磷脂酸，其…     

鱼类脂肪酸研究概况

因脂肪酸的独有特征,经常用于对鱼类的脂肪酸营养成分水平的研究。通过脂肪酸标志物,对鱼类脂肪酸生理特性进行分析研究,为鱼苗的培育提供理论依据。1脂肪酸特征脂肪酸是最简单的一种脂,从动、植物和微生物中已提取有近百种脂肪酸,极少游离脂肪酸存在,大多数脂肪酸以甘油三酯、磷脂和糖脂等结合形式存在,构成了更复杂的脂的成分。     

基于UPLC-Q-TOF/MS代谢组学技术探究α-酮戊二酸对碳酸盐碱胁迫下鲫血清代谢的影响

为探究饲料中添加α-酮戊二酸(α-ketoglutarate,AKG)对碳酸盐碱生境胁迫下鲫(Carassius auratus)血清代谢变化的影响机理,设置淡水对照组(Con组)、NaHCO₃暴露组(CA组)以及NaHCO₃暴露AKG饲料添加组(AKG组),采用UPLC-Q-TOF/MS代谢组学技术,结合主成分分析(PCA)和正交偏最小二乘判别分析(OPLS-DA)等多元模式识别技术分析鲫血清代谢物组成及含量变化特征,鉴定显著差异代谢物并进行相关代谢通路分析。结果显示,与对照组相比, CA组有27个差异代谢物,富集到了甘油磷脂代谢、亚油酸代谢、色氨酸代谢等12条代谢通路;与CA组相比, AKG组有38个差异代谢物,富集到了甘油磷脂代谢、亚油酸代谢、不饱和脂肪酸生物合成等14条代谢通路。研究结果表明,碳酸盐碱胁迫会造成鱼类氧化应激损伤,发生甘油磷脂代谢、鞘脂代谢和能量紊乱,而饲料中添加AKG能够促进TCA循环提供稳定的碳源和能量供应,通过正向调节甘油磷脂代谢、鞘脂代谢和氨基酸代谢等代谢途径来提高盐碱胁迫下鱼类的抗氧化能力和免疫能力,从而缓解盐...     

鱼类生长激素基因的研究现状及展望

鱼类的生长激素基因在鱼类生长发育和新陈代谢过程中发挥着极其重要的生物学作用。就鱼类生长激素基因(fGHG)的分离、活性检测、结构、分子克隆及在体外表达与基因转移等方面的研究进行了综述,并对其未来的研究策略和发展方向进行了展望。     

鱼体脂肪、蛋白质含量的季节变化对鱼类生活史的影响

鱼体脂肪、蛋白质含量的季节变化是鱼类生物学的一个重要特征,它与洄游、性腺发育、繁殖力、体长等都具有密切的关系,反映了鱼类生活史的不同阶段变化过程.本文根据国内外对鱼类脂肪、蛋白质含量的研究资料,初步阐述了脂肪、蛋白质含量在鱼类洄游、性腺发育、繁殖力等方面所起的作用及机理,指出了研究鱼类能量学对于更好了解鱼类的生物学特征、鱼产品加工业以及制订渔业管理措施等具有重要的意义.     

鱼类肠道菌群与机体脂质代谢关系研究进展

鱼类肠道内存在着大量的微生物类群,其在宿主生长发育、代谢及免疫调控过程中扮演着重要的角色。大量研究显示肠道菌群与宿主脂代谢关系密切,能够通过调节肠道短链脂肪酸(short-chain fatty acids, SCFAs)、内毒素(lipopolysaccharide, LPS)、胆汁酸、氧化三甲胺等菌群代谢产物以及肠上皮细胞的通透性,影响宿主脂质代谢。本文对国内外鱼类肠道菌群及其与机体脂质代谢作用关系进行梳理,综合报道了鱼类肠道菌群的组成、脂类营养对鱼类肠道菌群的影响、鱼类肠道菌群与机体脂质代谢的关系及基于肠道菌群调控鱼类脂质代谢的策略。在鱼类肠道中,菌群种类及结构的变化或可作为鱼类脂代谢紊乱的早期诊断标志。在此基础上,基于肠道菌群稳态维持而采取调控手段,如合理应用益生菌、益生元等,或将为鱼类等水产动物脂质代谢紊乱防控提供新的方法。     

基于耳石微化学分析的鱼类种群生态学研究进展

研究鱼类的种群生态学,破解其数量特征、生境利用、种群结构和动态变化等种群属性是保护和合理开发天然渔业资源的基础。耳石微化学分析是破解鱼类的种群生态学难题的新颖而有力的手段,不仅可以反演鱼类生活史过程中所经历的环境条件,还可溯源资源群起源的产卵场等关键生境,在鱼类资源种群空间结构形成机制研究及动态评估中具有优势。本文在分析耳石元素组成及其沉积特征的基础上,重点介绍了耳石微化学分析在鱼类种群生态学(如反演鱼类生活史、评估种群结构、把握关联性和破解混合群体的构成与来源等)中的应用进展,也客观评述了耳石微化学分析在鱼类种群生态学研究中的局限性与解决途径,并对今后相关技术的发展趋势及需要关注的科学问题进行了展望。     

The role of phospholipids in nutrition and metabolism of teleost fish

It has been known for almost 25 years now that inclusion of intact phospholipids in the diet could improve culture performance of various freshwater and marine fish species. The primary beneficial effect was improved growth in both larvae and early juveniles, but also increased survival rates and decreased incidence of malformation in larvae, and perhaps increased stress resistance. Determination of absolute dietary requirements has been hampered by the use, in different dietary trials, of a wide range of phospholipid preparations that can vary greatly both in phospholipid content and class composition. Larval studies have been compromised further by the need on many occasions to supply phospholipid through enrichment of live feeds with subsequent re-modelling of the phospholipid and fatty acid compositions. Generally, the levels of phospholipid requirement are around 2–4% of diet for juvenile fish and probably higher in larval fish. The effects were restricted to young fish, as a requirement for dietary phospholipids has not been established for adult fish, although this has been virtually unstudied. As the majority of studies have used crude mixed phospholipid preparations, particularly soybean lecithin, but also other plant phospholipids and egg yolk lecithin, that are enriched in several phospholipids, it has been difficult to elucidate which specific phospholipid classes impart beneficial effects. Based on the few studies where single pure phospholipid species have been used, the rank order for efficacy appears to be phosphatidylcholine > phosphatidylinositol > phosphatidylethanolamine > phosphatidylserine. The efficacy of other phospholipid classes or sphingolipids is not known. The mechanism underpinning the role of the phospholipids in larval and early juvenile fish must also explain their lack of effect in adult fish. The role of phospholipids appears to be independent of fatty acid requirements although the presence of an unsaturated fatty acid at the sn-2 position may be important. Similarly, the phospholipid requirement is not related to the delivery of other essential dietary components such as the bases choline and inositol. Studies also suggested that the phospholipid effect was not due to generally enhanced emulsification and digestion of lipids. Rather the evidence led to the hypothesis that early developing stages of fish had impaired ability to transport dietary lipids away from the intestine possibly through limitations in lipoprotein synthesis. The current hypothesis is that the enzymic location of the limitation is actually in phospholipid biosynthesis, perhaps the production of the glycerophosphobase backbone and that dietary supplementation with intact phospholipids in larvae and juvenile fish compensated for this. Thus, dietary phospholipids increase the efficiency of transport of dietary fatty acids and lipids from the gut to the rest of the body possibly through enhanced lipoprotein synthesis.     

大黄鱼幼鱼饲料中大豆磷脂油与菜籽油的适宜配比

配制浓缩大豆磷脂油与精制菜籽油的添加比例分别为0:6、2:4、4:2和6:0的4种等氮、等能和等脂的饲料(P0R6、P2R4、P4R2和P6R0),在海水浮式网箱中,养殖初始体重为(20.84±0.05)g的大黄鱼(Larimichthys crocea)幼鱼51 d,每个处理组设3个重复,每个重复40尾鱼。通过评定2种油脂的不同配比对大黄鱼幼鱼的生长、体组成和脂肪酸组成的影响,以得出大黄鱼幼鱼饲料中大豆磷脂油与菜籽油的适宜配比。结果显示,各组实验鱼的存活率均高于91%,且无显著差异(P0.05)。P2R4组实验鱼的特定生长率显著高于P4R2和P6R0组(P0.05)。P2R4组实验鱼的蛋白质沉积率和脂肪沉积率显著高于P0R6和P6R0组(P0.05)。P0R6和P2R4组全鱼的粗脂肪含量显著高于P4R2和P6R0组(P0.05)。全鱼和肌肉的脂肪酸组成受实验鱼所摄食饲料的脂肪酸组成的影响。P6R0饲料显著降低了实验鱼的肝脏脂肪含量和肥满度(P0.05)。研究表明,大黄鱼幼鱼饲料中浓缩大豆磷脂油与精制菜籽油的适宜配比为2:4。     

水产加工副产物中磷脂和鱼油的分离及脂质组学研究

为更好地对水产加工副产物进行加工利用,本实验建立了从水产加工副产物中同时提取制备磷脂和鱼油的方法,并分别利用多维度串联质谱鸟枪法和气相色谱法对样品的磷脂和鱼油的脂肪酸化合物进行脂质组学研究。利用改进Folch法和丙酮沉淀法制备得到副产物中的磷脂和鱼油,比较了5种不同萃取液的提取效率,其中CH2Cl2-Me OH(1∶2,V/V)混合液同时提取磷脂和鱼油效果最佳,提取率分别为0.97%和28.05%。鱼油经甲酯化反应,以正己烷为溶剂直接进样,利用气相色谱法分析脂肪酸甲酯成分,磷脂样品采用流动注射直接进样,经三重四级杆质谱母离子扫描(Pre IS)和中性质量丢失扫描(NLS)对磷脂分子实现源内分离鉴定和定量分析。结果显示,鱼油中主要含有油酸、亚油酸、棕榈酸等23种脂肪酸,其中不饱和脂肪酸占75.97%;磷脂样品中共检出磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇和磷脂酰丝氨酸4类共69种磷脂分子,并测出了许多含有DHA、EPA链的磷脂,如16∶0/20∶5、16∶0/22∶6、18∶1/22∶6、18∶0/22∶6、20∶0/22∶6等。研究表明,该方法能同时提取磷脂和鱼油,并且前处理简单、提取效率高,能够实现对资源的合理利用。     

The Effects of Soybean Lecithin Supplementation to a Practical Diet Formulation on Juvenile Channel Catfish,Ictalurus punctatus: Growth,Survival, Hematology,Innate Immune Activity,and Lipid Biochemistry

A feeding trial was conducted to determine the effects of soy lecithin supplementation on production performance of juvenile channel catfish, Ictalurus punctatus (mean ± SE; 5.8 ± 0 g). The basal diet consisted of a practical dietary formulation for channel catfish, containing 4.3% endogenous phospholipids (PL) from dietary ingredients, to which supplemental PL from soybean lecithin were added. The study diets were 1 control and 2 experimental diets to which 0, 2, or 4% supplemental lecithin was added, respectively. Soy lecithin inclusion did not affect survival, growth, feed consumption, whole‐body total lipid, innate immune response, plasma cholesterol or triglyceride concentrations, or hepatosomatic index. Feed conversion (gain/intake) improved in fish fed 4% supplemental lecithin compared with 0% lecithin. Whole‐body crude protein was greater in fish fed 2% supplemental lecithin compared with 0% lecithin, while 4% supplemental lecithin was intermediate. Phosphatidylcholine (PC) content was greater in fish fed 2 or 4% lecithin than 0% lecithin. Plasma concentrations of PC were inversely proportional to dietary concentrations. Liver glycogen was greater in fish fed 0% lecithin compared with 2 or 4% lecithin. Liver lipid and phospholipid were lower in fish fed 0% lecithin than 2 or 4% lecithin. The dietary phospholipid requirement, if any, of juvenile channel catfish for growth and survival is less than or equal to 4.3% (1.5% PC) of the diet. Feed conversion is improved in channel catfish fed diets supplemented with 4% soy lecithin (7.2% phospholipid; 5.1% PC), which might offset additional costs due to phospholipid supplementation. Dietary soy lecithin inclusion altered plasma and liver lipid composition, but it is unknown whether these effects can alter the ability of juvenile catfish to survive and grow under various conditions.     

Lipid class composition of benthic-pelagic fishes (Cottocomephorus, Cottoidei) from Lake Baikal

A study was made of the lipid class composition in liver, gonads and red and white muscles of two endemic Baikal fish species Cottocomephorus grewingki and Cottocomephorus inermis. The main lipid classes were triacylglycerols and phospholipids. The highest levels of triacylglycerol (81.8%) were found in the liver of C. inermis males, and of phospholipid (38.3%) – in males testes of both species. The main phospholipid classes were phosphatidylcholine and phosphatidylethanolamine, which varied in examined organs and tissues in both fish species from 44.3 to 78.7%, and from 16.8 to 42.1%, respectively.     

The fatty acid compositions of established fish cell lines after long-term culture in mammalian sera

The effect of long-term culture of fish cells in mammalian serum on the phospholipid fatty acid composition was investigated. All the cell lines studied had much lower levels of polyunsaturated fatty acids (PUFA) than those found in intact fish tissues. In particular (n-3) PUFA were considerably depleted in the cultured cell lines, leading to very low (n-3)/(n-6) ratios in all the phospholipid classes. In general the cells were rich in 18:1, 16:0, 18:0 and 16:1 with 20:4(n-6) and 22:6(n-3) as the major PUFA. The fatty acid composition reflected the composition of the fetal calf serum added to the media rather than their fish tissue origins. The results were discussed in relation to the roles of PUFA in general cell metabolism and more specifically the role of (n-3) PUFA in fish cells.     

饲料磷脂水平对巴丁鱼生长的影响

选取900尾健康的巴丁鱼(约1.4 g/尾),随机分成5个处理组(磷脂水平分别为0%、1%、2%、3%、4%),每组设3个重复,投喂同一种饲料,每个重复60尾鱼放养于一个水泥池(1.52 m×1 m×1 m)中。试验期56 d,试验水温为25～27℃。试验结果显示,各组的质量增加率、特定生长率随饲料磷脂水平的升高而升高(P>0.05),当磷脂水平为4%时,以上2个指标均达最高,分别为(1484.95±36.50)%、(4.92±0.26)%。第5组饲料系数最低(1.00±0.05)(P>0.05)。饲料磷脂水平显著影响巴丁鱼的肥满度、肝脏脂肪含量和肌肉脂肪含量(P<0.05)。第5组的肥满度最高(1.24±0.21),显著高于其他4组(P<0.05);第1组的肝脏脂肪含量最高(3.71±0.47%),与第3、4、5组差异显著(P<0.05)。第4、5组的肌肉脂肪含量最低,显著低于前3组(P<0.05)。     

Phospholipase A<Subscript>1</Subscript> activity of crude enzyme extracted from the ovaries of skipjack tuna

The phospholipid class composition, fatty acid composition and phospholipase A₁ (PLA₁) activity from the ovaries of skipjack tuna were compared with those of six other species of marine fish. In the skipjack ovaries, the lysophosphatidylcholine (LPC) proportion for the phospholipid, the docosahexaenoic acid (DHA) percentage for the total fatty acids of the phospholipids and the PLA₁ activity of the crude enzyme were the highest among those of the seven species. The optimum pH and temperature for the PLA₁ activity of the crude enzyme from the skipjack ovaries were in the range of pH 6–7 and 20–30°C, respectively, and calcium ions were not required. As a substrate, phosphatidylcholine was more easily hydrolyzed than phosphatidylethanolamine by this enzyme, and the plasmalogen-type phospholipid was much lower than the acyl-type phospholipid. After a 6-h hydrolysis reaction of the purified phospholipid extracted from the mixed ovaries of skipjack and yellowfin tuna by this enzyme, the LPC ratio of the phospholipid increased from 20 to 72.6% and the percentage of DHA for the total fatty acids of the phospholipid also increased. Thus, skipjack ovaries might possibly be used as a source of PLA₁.     

Improvement of Antioxidant Activity of Grass Carp (Ctenopharyngodon idella) Protein Hydrolysate by Washing and Membrane Removal Pretreatments and Ultrasonic Treatment

To improve the antioxidant activity of grass carp hydrolysate, washing and membrane removal pretreatments and ultrasonic treatment were applied in this study. Various pretreatment methods (washing methods and membrane removal methods) for removing the prooxidants and phospholipid in minced fish were evaluated. The effects of ultrasonic treatment prior to enzyme hydrolysis on the antioxidant activities of minced carp hydrolysate were investigated. The minced carp subjected to washing with 0.4% NaCl solution and subsequent membrane removal with CaCl₂ and citric acid solution had the lowest content of prooxidants and phospholipid remaining in the minced fish. The hydrolysate produced from washing/membrane removal pretreated carp with ultrasonic treatment for 20 min had the highest ferric reducing antioxidant power and scavenging activities against 1,1-diphenyl-2-picrylhydrazyl and 2,2?-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals. This suggested that the combination approach of washing/membrane removal pretreatment and ultrasonic treatment could improve the antioxidant activity of carp hydrolysate, and this hydrolysate could be a potential antioxidant ingredient for functional foods.     

The amino acid and fatty acid compositions of selected tissues of the dolphin fish (Coryphaena hippurus) and their nutritional implications

The amino acid and fatty acid compositions of muscle, gill, intestine, liver, ovaries, and whole bodies from captive juvenile and adult, and wild adult dolphin fish (Coryphaena hippurus) were determined. Essential amino acid ratios (A/E ratios) of the whole body and individual tissues were calculated and compared. In addition, the concept of a metabolic A/E ratio calculated from known daily protein turnover rates and from the amino acid profiles is introduced. Fatty acid profiles of phospholipid (PL) and triglyceride (TG) fractions in muscle and liver were also compared.

There were few differences in the amino acid and fatty acid profiles of tissues between the different groups of dolphin fish examined. Linolenic series fatty acids were quantitatively the most important polyunsaturates in tissue PL fractions. C22: 6n−3 was the major polyunsaturate present, accounting for approximately 20% of the total PLs in muscle and liver. There was no significant difference in tissue essential amino acid patterns between adult fish raised in captivity, and adult fish caught in the wild. However, the muscle of juvenile fish was lower in arginine and histidine contents than the muscle of adult fish. Ovaries had the lowest arginine, histidine, and tryptophan contents of all tissues measured.

Calculated A/E ratios of the muscle and whole body, and A/E ratios based on the metabolic rates for protein turnover in muscle, gill, and intestine, were similar. All ratios predicted an ontological increase in dietary arginine, histidine, and tryptophan needs of dolphin fish consistent with the changes noted in tissue amino acid contents.

It is concluded that the calculated A/E ratios and fatty acid profiles of dolphin fish tissues may be useful guides in formulating diets for the culture of this species. The results obtained suggest that the requirements for arginine, histidine, and tryptophan may differ between subadult and adult fish. Dietary needs for linolenic series HUFAs, especially C22:6n−3, are likely high throughout the life of this fish.