氧化油脂对斑点叉尾鮰生长、体色和抗氧化能力的影响

为考察正常及氧化鱼油、豆油、混合油脂(鱼油﹕豆油=1﹕1)对斑点叉尾鮰(Ictalurus punctatus)生长性能、体色和肝脏抗氧化能力的影响, 设计6组等氮等脂饲料, 分别添加6%鱼油、6%豆油、3%鱼油+3%豆油、6%氧化鱼油、6%氧化豆油、3%氧化鱼油+3%氧化豆油, 饲喂6组初始体重(150.5±4.2 g)的斑点叉尾鮰8周, 每组3个重复, 每个重复14尾鱼。结果表明, 摄食6%鱼油、6%豆油、3%鱼油+3%豆油饲料的斑点叉尾鮰在增重率、饲料系数、肌肉组成、体色和肝脏抗氧化指标上均无显著差异(P>0.05); 摄食3组氧化油脂饲料后, 鱼体增重率和肌肉粗脂肪含量降低(P<0.05), 饲料系数和背部、尾部皮肤b*(黄度值)增加(P<0.05), 肝脏丙二醛(MDA)和血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、总胆红素(TBIL)和直接胆红素升高(DBIL)(P<0.05), 肝脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽降低(GSH)(P<0.05), 而肌肉色度值(L*、a* 、b*)和肌肉水分、粗蛋白质、灰分含量无显著差异(P>0.05)。以上结果表明, 6%氧化油脂(鱼油、豆油或混合油脂)导致斑点叉尾鮰生长性能下降、皮肤黄度增加、肝脏抗氧化能力受损; 豆油可替代斑点叉尾鮰饲料中鱼油的使用, 而不会对生长产生负面影响。     

灵芝孢子油脂肪酸组分的分析

采用气相色谱与质谱(GC-MS)联用分析,从超临界CO2萃取孢子油中鉴定出18种脂肪酸成分,包括6种不饱和脂肪酸、7种饱和脂肪酸、2种环链脂肪酸,以及己酸、辛酸、壬酸等短链脂肪酸。GC定量分析结果表明:灵芝孢子油中检出9种已知脂肪酸,不饱和脂肪酸总量为73.6%;其中,主体成分油酸(C18∶1)、亚油酸(C18∶2)和棕榈酸(C16∶0)等含量分别为57.5%、13.4%、19.6%;此外,不饱和脂肪酸十六碳烯酸(C16∶1)、亚麻酸(C18∶3)等不饱和脂肪酸含量为2.2%、0.5%。     

稀有(鱼句)鲫的脂肪酸组成

稀有(鱼句)鲫汉源种群和彭州种群全鱼中共检测到3种饱和脂肪酸(SFA),它们是C14∶0、C16∶0、C18∶0.4种单不饱和脂肪酸(MUFA),它们是C14∶1、C16∶1、C18∶1、C20∶1.4种多不饱和脂肪酸(PUFA),它们是C18∶2、C20∶4、C20∶5(EPA)、C22∶6(DHA).SFA 占总脂肪酸的23.63-28.97%,MUFA 占40.73-54.32%,PUFA 占9.96-23.17%,EPA占0.41-1.74%,DHA占0.11-5.37%.EPA 含量一般低于 DHA.UFA(MUFA+PUFA)%＞SFA%,且 MUFA%＞PUFA%,n-3FA/n-6FA为0.33-0.99.此外还测定了鱼肌、内脏脂肪、肝脏、性腺等的脂肪酸组成和含量.     

饥饿对小规格斑点叉尾鮰体重及鱼体生化组成的影响

将180尾初始体重为（41.9 ± 0.5）g的斑点叉尾鮰放养于18个室内容积为300L的水族箱中进行饥饿处理12周,每箱放10尾,每2周取样一次,研究长期饥饿胁迫下斑点叉尾鮰生长和鱼体生化组成的变化,尤其是肌肉氨基酸和脂肪酸组成的变化。实验结果表明：斑点叉尾鮰的体重、肥满度、脏体比、肝体比和脂体比随着饥饿时间的延长显著降低（p < 0.05）;饥饿过程中全鱼的蛋白质、脂肪含量显著下降（p < 0.05）,水分含量显著增加（p< 0.05）,而灰分含量变化不大;肌肉中蛋白质含量前6周变化不显著（p > 0.05）,而6周后显著降低（p < 0.05）,脂肪、糖原和灰分含量随着饥饿时间的延长显著降低（p < 0.05）,水分含量显著增加（p < 0.05）;肝脏中的蛋白质和水分含量随饥饿时间的延长显著上升（p < 0.05）,粗脂肪和糖原的含量则显著下降（p < 0.05）;在12周的饥饿时间内,总的必需氨基酸所占的百分比变化不显著（p > 0.05）,而总的必需氨基酸和总的非必需氨基酸的比值显著增加（p < 0.05）;斑点叉尾鮰肌肉中总饱和脂肪酸、总单不饱和脂肪酸和n-6 系列脂肪酸的百分含量显著下降（p < 0.05）,而总的n-3系列脂肪酸含量显著增加（p < 0.05）。n-3/n-6脂肪酸的比值随饥饿时间的延长而显著升高（p < 0.05）。以上结果说明：斑点叉尾鮰在饥饿条件下优先动用机体的贮存性物质（脂肪和糖原）作为能源的供给物,而后才被迫动用组织或器官中的功能性物质蛋白质;长期饥饿胁迫下斑点叉尾鮰优先保留必需氨基酸及EPA、DHA等高度不饱和脂肪酸。     

两种海桐属植物种子油脂肪酸组成的分析评价

采用有机溶剂抽提了海桐属 2种植物 (海桐和皱叶海桐 )的籽油 ,使用气相色谱法 (GC)分析鉴定了其油脂的脂肪酸组分。 2种籽油均含有 6种脂肪酸 ,主要脂肪酸成分均为软脂酸 (C16∶0 )和油酸 (C18∶1)。其含量 ( % )分别为 :软脂酸 (C16∶0 ) 2 9.66,3 4 .72 ;油酸 (C18∶1) 66.4 3 ,62 .54。这两种油脂中 ,单不饱和脂肪酸油酸占优势 ,因而品质优良。提示海桐属植物籽油可作为保健型食用油研究和开发利用     

条石鲷仔、稚、幼鱼脂肪酸组成变化研究

通过采用GC/MS法研究了条石鲷(Oplegnathus fasciatus)仔鱼、稚鱼及幼鱼阶段的脂肪酸组成和变化特点。共检测到28种脂肪酸,其中饱和脂肪酸(SFA)13种,单不饱和脂肪酸(MUFA)7种,多不饱和脂肪酸(PUFA)8种。结果表明:条石鲷鱼苗内源性营养阶段以饱和脂肪酸C16∶0、C20∶0及单不饱和脂肪酸C16∶1、C18∶1作为能量代谢的主要来源;必需脂肪酸C20∶4(n-6)(AA)、C22∶5(n-3)(DPA)和C22∶6(n-3)(DHA)在稚鱼期含量较低,∑EPA+DHA仅为6.89%,认为是发生稚鱼"胀鳔病"的主要原因;仔鱼开口前体内的DHA和EPA是由母体卵黄提供的。     

老年和青年大鼠大脑皮质脂肪酸组成及含量的对比分析

大脑功能与脑内脂肪酸成分密切相关,分析研究老年时脑脂肪酸组成及含量有助于阐明不同类型脂肪酸在老年认知能力降低过程中的作用.采用Y型电迷宫测试老年组(22月龄)和青年组(3月龄)大鼠的学习记忆能力,表明老年组大鼠的学习记忆能力显著下降.用气相色谱的方法分析大鼠大脑皮质脂肪酸的组成及含量,显示老年组和青年组大脑皮质均含有16种脂肪酸.以C23:0为内标对各种脂肪酸进行了定量,老年组总脂肪酸含量比青年组降低约15%,各脂肪酸中含量下降的脂肪酸有长链饱和脂肪酸(C14:0、C16:0、C18:0)及多不饱和脂肪酸(C18:3、C20:4、C22:4、C22:6),含量升高的脂肪酸有单不饱和脂肪酸C20:1、C24:1.用峰面积归一法计算了各脂肪酸的相对含量,老年组相对含量下降的脂肪酸有C18:0、C20:4、C22:6,相对含量升高的有极长链饱和脂肪酸(C20:0、C24:0)及单不饱和脂肪酸(C16:1、C18:1、C20:1、C22:1、C24:1).相关性分析显示,大鼠学习能力与脑皮质C22:6、C22:4、C20:4水平呈正相关,与C20:1、C24:1水平呈负相关.上述结果为阐明不同脂肪酸在老年大脑认知功能障碍中的作用提供了实验依据。     

丝状真菌被孢霉产生油脂的研究

被孢霉的三个菌株Mortierella sp.M10,M13与M14生长在以葡萄糖为碳源、尿素为氮源的液体培养基中,所得到的菌丝体内堆积含γ-亚麻酸的油脂。油脂产率以M10菌株为高,而油脂中的γ-亚麻酸含量却以M14菌株为高。这种油脂的脂肪酸中,所含饱和脂肪酸主要有豆蔻酸(C14:0),棕榈酸(C16:0)和硬脂酸(C18:0);所含不饱和脂肪酸主要有棕榈油酸(C16:1),油酸(C18:1),亚油酸(C18:2)以及γ-亚麻酸(C18:3,n-6)。上述被孢霉菌株的培养物接种在含葡萄糖、尿素的培养基中生长大约48小时后,菌丝体顶端细胞形成鼓胀球状,此后仍继续胀大。菌体细胞形态的这种特异变化,可能与胞内油脂的累积有关。     

利用毕赤酵母发酵废液培养原始小球藻的研究

以毕赤酵母发酵废液为水源并提供部分C源和N、P,在500 mL摇瓶中,比较了发酵废液培养基与SE基础培养基对原始小球藻的生长影响,并通过单因素和正交优化发酵废液培养基。结果表明,发酵废液培养基适合于原始小球藻的培养。利用发酵废液培养小球藻,在添加葡萄糖0.05 mol/L,硝酸钠0.01 mol/L,磷酸二氢钾0.003 mol/L,海绿素浓度300μL/L,培养7 d后最高生物量达6.56 g/L,油脂含量达33.68%,两者均高于SE基础培养基。油脂的脂肪酸组成分析表明,废液培养基培养下小球藻油脂的脂肪酸组成主要是C16∶0(25.12%)、C18∶0(4.69%)、C18∶1(50.46%)、C18∶2(6.78%)、C18∶3(8.58%),而SE培养基培养的小球藻油脂脂肪酸组成主要是C16∶0(24.56%)、C18∶0(20.36%)、C18∶1(16.66%)、C18∶2(14.32%)、C18∶3(30.98%),两种培养基培养所得藻油脂肪酸组成虽相差较大,但均适合作为生物柴油的原料。     

稀有鮈鲫的脂肪酸组成

稀有鲫汉源种群和彭州种群全鱼中共检测到 3种饱和脂肪酸 (SFA) ,它们是C1 4∶0、C1 6∶0、C1 8∶0。 4种单不饱和脂肪酸 (MUFA) ,它们是C1 4∶1、C1 6∶1、C1 8∶1、C2 0∶1。 4种多不饱和脂肪酸 (PUFA) ,它们是C1 8∶2、C2 0∶4、C2 0∶5 (EPA)、C2 2∶6 (DHA)。SFA占总脂肪酸的2 3 6 3— 2 8 97% ,MUFA占 40 73— 5 4 3 2 % ,PUFA占 9 96— 2 3 1 7% ,EPA占 0 41— 1 74% ,DHA占 0 1 1— 5 3 7%。EPA含量一般低于DHA。UFA(MUFA +PUFA) % >SFA % ,且MUFA % >PUFA % ,n 3FA/n 6FA为 0 3 3— 0 99。此外还测定了鱼肌、内脏脂肪、肝脏、性腺等的脂肪酸组成和含量     

斑点叉尾鮰源普通变形杆菌的分离、鉴定及药敏特性

【目的】对患病斑点叉尾鮰进行病原菌分离、鉴定及药敏实验,为斑点叉尾鮰肠道坏死病的防控提供参考。【方法】从患病斑点叉尾鮰病灶、肝、脾和肾分离纯化病原菌,经理化特性测定及16S rRNA基因序列分析对其进行鉴定,开展人工感染试验,并利用纸片扩散法进行药敏特性分析。【结果】分离菌株k1为本次引发斑点叉尾鮰病害的致病菌,其对斑点叉尾鮰的LD50为2.82×10~5 CFU/g。菌株k1理化特性与普通变形杆菌Proteus vulgaris基本一致,16S rRNA基因序列与普通变形杆菌相似性最高,综合判定分离菌株为普通变形杆菌。分离菌株k1对环丙沙星、头孢唑林及头孢拉定等12种抗生素高度敏感,对苯唑西林、阿莫西林及痢特灵等7种抗生素耐药。【结论】分离菌株k1是斑点叉尾鮰病原菌,养殖时可选用庆大霉素及氟苯尼考等药物进行防控。     

Four members of the Sox gene family in channel catfish

The homologous sequences of human or mouse SOX1, SOX4 and SOX11 , and one novel Sox gene (named Ccf-SoxN ) were identified in the genome of channel catfish Ictalurus punctatus . Identification of these genes is a potential step in understanding development regulations including sex determination in channel catfish.     

Ligand binding specificity of a neutral L-amino acid olfactory receptor

1. The ligand binding specificity of the L-[3H]alanine binding site was investigated in isolated cilia preparations from the olfactory epithelium of channel catfish (Ictalurus punctatus) by competitive binding experiments. 2. Approximately 45 amino acids, derivatives and enantiomers were tested for the ability to compete with radiolabeled L-alanine for common binding sites. 3. Acidic and basic L-amino acids and imino acids did not compete as effectively as L-alanine for the receptor, while long-chain neutral ligands were only partially effective inhibitors of L-alanine binding. 4. D-Alanine and L-alanine derivatives with substituted alpha-amino or carboxyl groups exhibited decreased ability to compete for the receptor, paralleling their lower neurophysiological potency. 5. In combination, the ligand binding results were consistent with previous electrophysiological data in catfish, and suggest the presence of an olfactory receptor site that selectively recognizes short-chain neutral amino acids.     

Modes of stimulation of the teleost ear.

Microphonic potentials were recorded from the inner ears of a catfish (Ictalurus punctatus) and an African mouthbreeder (Tilapia macrocephala) in response to underwater sound stimulation and direct vibration of the head. The shape of the vibratory isopotential functions of frequency was similar in both species up to 600 HZ. Above 600 HZ, the sensitivity of Ictalurus continued to increase to 4000 HZ while the sensitivity of Tilapia declined. Deflation of the swim bladder did not affect the response to vibration in either species, the response of Tilapia to the underwater sound stimulus being minimal and unaffected by removal of the swim bladder. Ictalurus was pressure-sensitive to above 4000 HZ, ther being a significant dedline in the response with deflation of the swimbladder.     

Nocturnal activity and feeding of juvenile channel catfish,Ictalurus punctatus,around offshore breakwaters in Lake Kasumigaura,Japan

Ichthyological Research - Diel changes in occurrence and feeding habits of juvenile channel catfish (Ictalurus punctatus) were examined in offshore breakwater areas in Lake Kasumigaura, Japan, to...     

Anaerobic bacteria associated with epizootics in grey mullet (Mugil cephalus) and redfish (Sciaenops ocellata) along the Texas Gulf Coast

Anaerobic bacteria tentatively identified as species of Catenabacterium were recovered from brain, liver, kidney and blood of fish involved in a massive epizootic of grey mullet (Mugil cephalus) and redfish (Sciaenops ocellata). Pathogenicity was demonstrated for grey mullet (M. cephalus) and sea catfish (Arius felis) but not for channel catfish (Ictalurus punctatus) or white mice. Diseased fish were disoriented, weak and swimming at the surface of the water. Thioglycolate and salt bovine blood agar containing 40 microg/ml gentamicin were useful as selective culture media.     

Improved Growth and High Inheritance of Melanocortin-4 Receptor (mc4r) Mutation in CRISPR/Cas-9 Gene-Edited Channel Catfish,Ictalurus punctatus

Marine Biotechnology - Effects of CRISPR/Cas9 knockout of the melanocortin-4 receptor (mc4r) gene in channel catfish, Ictalurus punctatus, were investigated. Three sgRNAs targeting the channel...     

Upper and Lower Temperature Tolerances of Juvenile Freshwater Game-Fish Species Exposed to 32 days of Cycling Temperatures

Hydrobiologia - Temperature tolerance quantified as CTminima and CTmaxima of channel catfish (Ictalurus punctatus), largemouth bass (Micropterus salmoides) and rainbow trout (Oncorhynchus mykiss)...     

Putative SNP discovery in interspecific hybrids of catfish by comparative EST analysis

In this study, we identified putative SNP markers within genes by comparative analysis of expressed sequence tags (ESTs). Comparison of 849 ESTs from blue catfish (Ictalurus furcatus) with >11,000 ESTs from channel catfish (I. punctatus) deposited in GenBank resulted in the identification of 1020 putative SNPs within 161 genes, of which 145 were nuclear genes of known function. The observed frequency of SNPs within ESTs of the two closely related catfish species was 1.32 SNP per 100 bp. The majority of identified SNPs differed between the two species and, therefore, these SNPs are useful for mapping genes in channel catfish x blue catfish interspecific resource families. The SNPs that differed within species were also observed; these can be applied to genome scans in channel catfish resource families.