ω-3多不饱和脂肪酸发酵生产中两个调控指标的探讨

为了调控长链ω 3多不饱和脂肪酸的发酵 ,对用于脂肪酸发酵调控的 2个指标 18∶3(α ) /18∶2和∑C18/∑C16进行探讨。对 2个指标从化学反应平衡角度进行阐述 ,进一步证明在合适的条件下 ,头孢霉 18∶3(α ) /18∶2的变化趋势和二十二碳六烯酸变化趋势一致 ;轮梗霉∑C18/∑C16和二十碳五烯酸变化趋势一致。 18∶3(α ) /18∶2和∑C18/∑C16可以作为发酵生产二十二碳六烯酸和二十碳五烯酸的调控指标。     

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%。     

西南大西洋春夏季阿根廷无须鳕脂肪酸组分的时空特性

阿根廷无须鳕(Merluccius hubbsi)是西南大西洋较为重要的鱼种,具较高的商业价值,为底拖网渔业的主要捕捞对象。本研究利用气相色谱质谱联用仪测定了阿根廷无须鳕肌肉组织脂肪酸组成,探究各脂肪酸含量,包括饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)随体长、月份和纬度的变化。结果表明:各类脂肪酸含量高低次序依次为∑PUFA∑SFA∑MUFA;主要脂肪酸包括C22:6n3(DHA)、C16:0、C18:1n9c、C20:5n3(EPA)和C18:0,其中DHA的含量最高,占总脂肪酸含量的35.27%;高PUFA/SFA表明阿根廷无须鳕肌肉可作为PUFA的补充原料;∑SFA和∑PUFA在小体长组个体中(20.1~30.0 cm)的含量较高,特别是DHA和EPA,使得n-3/n-6增加,说明相对较大个体而言,小个体阿根廷无须鳕的营养价值更高;除n-3/n-6外,其余脂肪酸含量均无显著的月份差异;1月最高的n-3/n-6说明肌肉组织在该月份具有较高的营养价值。鱼体各脂肪酸含量随纬度和表温变化不明显。     

刀鲚胚胎及胚后发育早期脂肪酸组成变化

为掌握刀鲚(Coilia nasus)胚胎及胚后发育早期的脂肪酸变化规律,采用生化分析手段对刀鲚的胚胎(原肠期,受精后7～9 h)、0日龄仔鱼(初孵仔鱼)、3日龄仔鱼和5日龄仔鱼(开口前)的脂肪酸组成和含量进行了检测分析。结果显示,刀鲚发育早期的总脂占干物质的相对含量均较高(53.10%～60.97%),干物质的总脂相对含量随个体发育显著降低,单个个体的总脂含量随个体发育呈现剧烈下降趋势,数值从胚胎的43.62μg/ind剧烈下降到5日龄仔鱼的16.27μg/ind;水分含量随个体发育而升高。刀鲚发育早期上述4个时期的干样中检出6种饱和脂肪酸(SFA)、4种单不饱和脂肪酸(MUFA)和8种多不饱和脂肪酸(PUFA)。4个发育时期脂肪酸相对含量,C18:1n9c占绝对优势(50.39%～57.00%),C16:1丰富且稳定(13.77%～14.24%),C16:0也较丰富(7.45%～9.15%)。单不饱和脂肪酸(MUFA)比例占绝对优势(65.14%～72.26%),n-3与n-6系列多不饱和脂肪酸含量的比值(∑n3PUFA/∑n6PUFA)较小(1.78～2.38)。刀鲚胚胎孵化出膜期间,单个个体单不饱和脂肪酸(MUFA)实际减少程度较高,尤其是C18:1n9c(减少量为13.21μg/ind,减少比例达到55.49%)和C16:1(减少量和比例分别为3.30μg/ind和53.12%),而二十碳五烯酸(EPA)加二十二碳六烯酸(DHA)的减少程度较低(1.44μg/ind和38.41%),尤其是DHA(0.95μg/ind和36.52%)。然而,出膜后,仔鱼对单不饱和脂肪酸(MUFA)的利用相对较低(1.94μg/ind和14.17%),尤其是C18:1n9c(13.21μg/ind和12.41%)和C16:1(0.63μg/ind和21.81%);而对EPA+DHA利用相对较高(1.04μg/ind和45.10%),尤其是DHA(0.71μg/ind和42.61%)。研究表明,刀鲚胚胎优先蓄留EPA和DHA,仔鱼在摄食前大量利用EPA+DHA(特别是DHA),呈现出海水鱼类脂肪酸的利用特点。因此,建议在刀鲚亲本强化培育及产后培育中,增加投喂富含单不饱和脂肪酸(MUFA)(特别是C18:1和C16:1)的饵料,以加强刀鲚亲本的营养积累和产卵后亲本生理机能的恢复;在刀鲚育苗前期,要及时补充富含DHA和EPA的饵料,如,单胞藻、蛋黄等,以提高刀鲚仔鱼开口期间的成活率。     

斑点叉尾鮰鱼油脂成分分析

采用铁锅炼制提取斑点叉尾鮰内脏鱼油,然后加酸使其甲酯化,以气相色谱/质谱法分析鱼油中的脂肪酸.结果斑点叉尾鮰内脏纯油脂中鱼油达到99%.从鱼油中共鉴定出15种成分,有饱和脂肪酸及不饱和脂肪酸,还有少量烷烃类物质.不饱和脂肪酸含量为76.40%,其中多不饱和脂肪酸为18.03%,以C18∶ 2(16.23%)为主,单不饱和脂肪酸为58.37%,以C18∶ 1(54.88%)为主.饱和脂肪酸含量为20.91%,主要有C16∶ 0 (15.84%)和C18∶ 0(4.29%),多是低于C18以上的中长链脂肪酸.因此斑点叉尾鮰油脂可作功能性脂肪酸的重要膳食来源.     

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.     

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     

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。     

羊奶果种子脂肪酸组成和矿质元素分析

测定了羊奶果(Elaeagnus conferta Roxb.)种子脂肪酸组成以及矿质元素含量。结果表明:脂肪酸含量为1.98%,主要是油酸(C18:1)34.15%、亚油酸(C18:2)31.51%、软脂酸(C16:0)13.83%、硬脂酸(C18:0)2.88%。饱和脂肪酸:单不饱和脂肪酸:多不饱和脂肪酸含量比为1:2.23:2.75。矿质元素K高达7837.69mgkg-1,Fe为30.99mgkg-1、Zn为10.13mgkg-1,Na为259.5mgkg-1。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.