石莼属(Ulva)和浒苔属(Enteromorpha)绿藻的RAPD分析

于 1 997年下半年在大连石庙海区采集石莼、孔石莼、砺菜、缘管浒苔、肠浒苔、管浒苔、刚毛藻等 7种海藻样品 ,采用RAPD技术对大连地区绿藻门石莼属和浒苔属进行了初步的分子系统学研究。所试 60个引物中有 32个经扩增得到了 2 37个多态片段。应用PHYLIP软件包 ,按照UPGMA法和N -J法聚类分析的结果均表明 ,缘管浒苔 (Enteromorphalinza)与石莼属有较近的亲缘关系 ,应深入探究其分类地位。

浒苔(Enteromorpha prolifera)生长及孢子释放的生态因子研究

通过考察浒苔属浒苔藻体生长及孢子释放的生态因子条件,确定其各单因子的适应范围及最适范围。结果表明:浒苔藻体生长对盐度、温度、光照强度和酸碱度的适应范围分别为16～40、10℃～30℃、>9μmol/m2s、6～10,最适范围分别为24～28、20℃～25℃、>18μmol/m2s、8～9,在盐度、温度、光照强度和酸碱度分别为24、25℃、72μmol/m2s、8的条件下达到最大生长量;浒苔释放孢子对盐度、温度、光照强度和酸碱度的适应范围分别为12～40、15℃～35℃、>9μmol/m2s、6～10,最适范围分别为28～40、20℃～35℃、>36μmol/m2s、8～9,在盐度、温度、光照强度和酸碱度分别为32、35℃、144μmol/m2s、9的条件下达到最大释放量。浒苔藻体生长及孢子释放的各单因子适应范围基本相同,最适范围区别明显。

黄海海域浒苔属(Enteromorpha)生态特征初探

通过对2008年6月在黄海爆发的大型绿藻（浒苔属）进行实验室培养试验，对其生态特征有了初步了解。结果表明，该藻属广温、广盐性的海洋绿藻，对环境的适应能力和繁殖能力较强。在培养温度范围15～32℃，盐度范围5—29之间都能存活，其中水温为23℃，盐度为25和29时，其生长较好。在富营养水体环境中，其生长需要的消耗水中大量的N、P营养盐，并且在当N：P为10：1时生长率达到最大。

黄、渤海漂移浒苔(Enteromorpha prolifera)脂肪酸组成及聚类分析的研究

于2008年7月在黄、渤海区域采集了17个漂移浒苔样品,结合3个本地种,对其脂肪酸组成进行了GC-MS分析。结果表明,所有浒苔中优势脂肪酸为十六碳酸,相对含量在27.82%—43.27%之间。藻体中还含有丰富的PUFA,主要为9,12,15-十八碳三烯酸、6,9,12-十八碳三烯酸、9,12-十八碳二烯酸、8,11,14-二十碳三烯酸,另外还含有EPA不饱和脂肪酸。以欧式距离平方为距离测量技术,类间距用平均链锁法,对20个不同地理位置的浒苔样品进行聚类分析,结果分为4大类,所有漂浮浒苔聚为第一类,青岛和连云港的本地种分别聚为另三类,说明青岛近海漂浮的浒苔不是青岛本地生浒苔,而是从外海漂移过来的,第一类的聚类结果显示了浒苔的漂移路径。结果表明,藻类脂肪酸的系统聚类分析为海洋绿藻分类与量化评价提供了一种好方法。

浒苔(Enteromorpha prolifera)生活史的初步研究

通过实验室培养实验,全面地观察描述了浒苔生活史各个阶段的发育情况。雌雄异体的配子体成熟后,放散双鞭毛的配子,雌雄配子结合成合子进而发育成孢子体,配子也可以进行单性生殖发育成膜状的配子体。孢子体成熟放散四鞭毛的游孢子,游孢子固着后,可直接发育成配子体。其生活史是单倍体的配子体与二倍体的孢子体相互交替的同形世代交替。雌雄配子具有正趋光性,易大量聚集,结合后同游孢子一样都呈负趋光性。

浒苔Enteromorpha prolifera组织培养初步研究

通过将大型绿藻——浒苔切成一定大小的藻体片段,在实验室条件下用液体和固体平板组织培养的方法,系统地研究了在藻体切段条件下,浒苔组织块中细胞的发育路径和趋势。在培养的过程中发现叶状体中细胞的发育能力和方向都具有明显的极性,且浒苔组织块中细胞的发育速度和规模与组织块大小和其组织块中的位置有关。在切段培养的条件下,浒苔细胞有5种发育途径:1.分化为孢子囊,2.细胞极化下端延伸形成类似于假根的结构,3.分裂成细胞团并在后续的发育过程中成苗,4.细胞进一步极化形成带假根的单细胞苗,5.维持一定状态不再分化。而切段培养条件下,藻段中的不同细胞可能发生不同的发育情况。

浒苔(Enteromorpha prolifera)藻体发育的显微观察

通过显微镜观察以及石蜡切片法观察了浒苔属浒苔藻体的发育过程,阐述了浒苔从孢子释放到形成成熟藻体这一发育过程的显微特征。结果表明:浒苔孢子由成熟体细胞分化发育而成,每个成熟体细胞可形成10～30个孢子;孢子首先分裂为2细胞结构,2细胞具有明显的极性,基细胞发育成为假根,顶端细胞不断进行横分裂形成丝状体;丝状体顶端以下细胞通过纵分裂形成管状叶状体,顶端细胞始终保持横分裂;纵分裂分为切向分裂与径向分裂,切向分裂增加管状叶状体管周细胞数从而使管体增大,径向分裂形成管外壁突起细胞,最终发育为分枝;管状叶状体管腔内部有绒毛状的突起及糖蛋白成分的网架结构;当管状叶状体管周细胞达到30～50h,管腔内部突起消失,网架结构收缩拉紧,管壁细胞贴近形成片状叶状体;整个浒苔藻体始终保持极性发育。

高浓度CO_2对条浒苔(Enteromorpha clathrata)生长和一些生理生化特征的影响

本试验利用 CO2 培养箱，通过不同 CO2 浓度的空气通气培 养，研 究 高 浓 度 CO2 对 条 浒 苔 (Enteromorpha clathrata) 生长、光合作用及有关生理生化特征的影响。高浓度 CO2 使得海水中的溶解性无机碳浓度增加，而 pH 值下降。700μL/L 和 5 000μL/L 的 CO2 浓度培养条件使条浒苔的相对生长速率分别提高了 12 % 和 23 %，而光合能力均下降了 25 %。 5 000μL/L 的 CO2 浓度使得条浒苔光合作用光补偿点及无机碳补偿点提高；同时，条浒苔的叶绿素含量及可溶性蛋白含量下降，而可溶性碳水化合物含量增加；另外，条浒苔对 NO3- 的吸收速度增加，而硝酸还原酶活性则下降。700μL/L 的 CO2 浓度比 5 000μL/L 的 CO2 浓度对这些指标的影响较小。

Molecular phylogenetic analysis of attached Ulvaceae species and free-floating Enteromorpha from Qingdao coasts in 2007

Based on the sequence data of the nuclear ribosomal DNA internal transcribed spacer(ITS) 1,5.8 S,and ITS 2,the molecular phylogeny was analyzed on Ulvaceae species collected from Qingdao coasts in summer of 2007,including 15 attached Ulva and Enteromorpha samples from 10 locations and 10 free-floating Enteromorpha samples from seven locations.The result supported the monophyly of all free-floating Enteromorpha samples,implying the unialgal composition of the free-floating Enteromorpha,and the attached Ulvaceae species from Qingdao coasts were grouped into other five clades,suggesting that they were not the biogeographic origin of the free-floating Enteromorpha in that season.

湛江海域浒苔属Enteromorpha种类的形态与显微结构

用比较解剖学方法观察湛江沿海浒苔属(Enteromorpha)海藻的形态结构,并结合统计分析对其进行物种鉴定。结果表明,依据藻体分枝的有无、数量及分枝与主枝直径的大小等形态特征,鉴定的浒苔属海藻有6种1个变型,分别为缘管浒苔(E.linza)、肠浒苔(E.intestinalis)、扁浒苔(E.compressa)、浒苔(E.prolifera)、条浒苔(E.clathrata)、曲浒苔(E.flexuosa)和肠浒苔宽叶变型(E.intestinalis f.broadifolium)。藻体长度由大到小依次为浒苔、条浒苔、缘管浒苔、肠浒苔、扁浒苔和肠浒苔宽叶变型;细胞呈多角形,藻体的位置不同其细胞大小有所变化,除曲浒苔和条浒苔外,其他4种1个变型浒苔的中部细胞最小;所有种类的细胞均有淀粉核,其中肠浒苔、缘管浒苔和扁浒苔仅1个淀粉核,而其他种出现多个淀粉核,尤其条浒苔和曲浒苔数量最多,可达6个以上。定量描述浒苔属6种1个变型的形态特征、内部结构,并发现浒苔属海藻非中空管状的结构特征。

浒苔(Enteromorpha prolifera)的分类鉴定、生境习性及分布

结合过去的工作基础,对2008年5月底以来黄海西部沿海水域漂浮聚集的绿藻样品进行了分类学研究。经鉴定,其为绿藻门石莼目石莼科浒苔属的浒苔Enteromorpha prolifera,其主要分类鉴定特征为藻体暗绿色或亮绿色、管状扁压、中空、主枝明显、分枝较多、密集且细长。文中对其生境习性及其分布特征也作了较详细地介绍。

The possibility analysis of habitats,origin and reappearance of bloom green alga(Enteromorpha prolifera) on inshore of western Yellow Sea

Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008,authors analyze the necessary conditions and possible water area in China producing a large biomass,some reasons for firestorm,and the possibility of the reappearance of marine bloom green alga Enteromorpha prolifera.The change of habitats and the increase of nutritional levels related to the water area could be considered as direct reasons.It was transferred northward by the combination of the flow of rainwater,wind and alongshore marine current.The original region of large biomass produced is possibly located in the southwestern Yellow sea.It will possibly be appearing again in the coming years or in the future.A summary is also given referring to its reproduction,development and distribution worldwide.

不同地区浒苔(Enteromorpha prolifera)群体遗传多样性的ISSR分析

通过ISSR分子标记技术对6个不同地区浒苔(Enteromorpha prolifera)群体(浙江鳌江、浙江宁波、广东南澳、江苏南通、福建福鼎、浙江南麂岛)进行了遗传多样性分析.结果显示,从100条ISSR引物中筛选出5条引物,共得到36个清晰的扩增位点,其中多态性位点10个;6个地区浒苔的多态位点比率为27.78%,平均杂合度为0.1256,Shannon's信息指数为0.1795;群体间的遗传距离在0.0870-0.2062之间,平均遗传距离为0.1654.研究表明,6个地区浒苔的遗传多样性处于较低水平,遗传变异相对贫乏;它们之间的亲缘关系与其地理距离的远近没有直接的关系,并揭示6个地区的浒苔是属于同一物种.

Selenylation Modification of Degraded Polysaccharide from Enteromorpha prolifera and Its Biological Activities

Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities,but its molecular weight was greatly high which influenced the activity.Organic Se had higher biological activities and was safer than inorganic Se species.In the present study,Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H_2O_2 and ascorbic acid.By single factor and orthogonal experiments,the optimal degradation conditions were reaction time of 2 h,reaction temperature of 50℃,H_2O_2/ascorbic acid(n/n=1:1)concentration of 15 mmol L^(-1),and solid-liquid ratio of 1:50(g mL^(-1)).Then,the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method.The selenium content was 1137.29μg g^(-1),while the content of sulfate radical had no change.IR spectra indicated that the selenite ester group was formed.Degraded polysaccharide selenide was characterized and evaluated for antioxidant,antifungal and antibacterial activities.The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and·OH free radical.It had significant antibacterial properties for Escherichia coli,Bacillus subtilis and Salmonella spp.,and it also had significant antifungal properties for Apple anthrax.The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides.It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.

Acute toxicity of live and decomposing green alga Ulva (Enteromorpha) prolifera to abalone Haliotis discus hannai

From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva (Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.

Effect of temperature and irradiance on the growth and reproduction of Enteromorpha prolifera J.Ag.(Chlorophycophyta,Chlorophyceae)

Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate （SGR） of 10.47 at 25℃/40 μmol m^-2s^-1. Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 μm in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative cells could still divide actively in the algal tissues.

Effect of polysaccharide from Enteromorpha prolifera on maize seedlings under NaCl stress

In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We found that EP is a sulfated polysaccharide of high-molecular weight (Mw, 1 840 KDa) heteropolysaccharides and the main monosaccharide is rhamnose. The polysaccharide was applied to explore its effect on the growth of maize seedlings and its defense response under a salt stress. The results show that EP could promote the growth of maize seedlings under the salt stress. In addition, EP was shown able to significantly regulate membrane permeability and adjustment of osmotic substances such as soluble protein, soluble sugar, and proline, antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Therefore, EP is an effective salt-resistant substance for the growth of maize seedlings under NaCl stress.

Dietary Enteromorpha polysaccharide-Zn supplementation regulates amino acid and fatty acid metabolism by improving the antioxidant activity in chicken

Background:Enteromorpha prolifera(E.prolifera)polysaccharide has become a promising feed additive with a variety of physiological activities,such as anti-oxidant,anti-cancer,anti-diabetic,immunomodulatory,hypolipidemic,and cation chelating ability.However,whether Enteromorpha polysaccharide-trace element complex supplementation regulates amino acid and fatty acid metabolism in chicken is largely unknown.This study was conducted to investigate the effects of E.prolifera polysaccharide(EP)-Zn supplementation on growth performance,amino acid,and fatty acid metabolism in chicken.Methods:A total of 184 one-day-old Ross-308 broiler chickens were randomly divided into two treatment groups with 8 replicates,12 chickens per replicate,and fed either the basal diet(control group)or basal diet plus E.prolifera polysaccharide-Zinc(400 mg EP-Zn/kg diet).Results:Dietary EP-Zn supplementation significantly increased(P<0.05)the body weight,average daily gain,muscle antioxidant activity,serum HDL level,and reduced serum TG and LDL concentration.In addition,dietary EPZn supplementation could modulate ileal amino acid digestibility and upregulate the mRNA expression of amino acid transporter genes in the jejunum,ileum,breast muscle,and liver tissues(P<0.05).Compared with the control group,breast meat from chickens fed EP-Zn had higher(P<0.05)Pro and Asp content,and lower(P<0.05)Val,Phe,Gly,and Cys free amino acid content.Furthermore,EP-Zn supplementation upregulated(P<0.05)the mRNA expressions of mTOR and anti-oxidant related genes,while down-regulated protein degradation related genes in the breast muscle.Breast meat from EP-Zn supplemented group had significantly lower(P<0.05)proportions ofΣn-3 PUFA,and a higher percentage ofΣn-6 PUFA and the ratio of n-6/n-3 PUFA.Besides,EP-Zn supplementation regulated lipid metabolism by inhibiting the gene expression of key enzymes involved in the fatty acid synthesis and activating genes that participated in fatty acid oxidation in the liver tissue.Conclusions:It is concluded that EP-Zn complex supplementation regulates apparent ileal amino acid digestibility,enhances amino acid metabolism,and decreases oxidative stress-associated protein breakdown,thereby improving the growth performance.Furthermore,it promotes fatty acid oxidation and restrains fat synthesis through modulating lipid metabolism-related gene expression.

Study on Growth,Serum Biochemical and Antioxidant Enzyme Indices of Juvenile Siganus guttatus Fed with Enteromorpha prolifra and Artificial Feed

In order to provide reference for using Sigartus guttatus to control overgrowth of Ertteromorpha prolifra, the growth, serum biochemical and antioxidant enzyme indices of juvenile S. guttatus respectively fed with E. prolifra and artificial feed were studied. One hundred and eighty individuals were cultivated for 90 days in six 2.5 m × 1.5 m × 1.5 m cages （30 ind. per cage） which mesh size were 0.5 mm. The experimental animals were divided into two dietary groups （ three cages for each group） that were fed with E. prolifra and artificial feed respectively. During the culture period, temperatures ranged from 23.0 to 26.5℃, pH was between 7.8 and 8.2, dissolved oxygen was more than 5.0 mg/L. The weight gain rate, specific growth rate, relative growth rate, hepato-somatic index of juvenile S. guttatus fed with E. prolifra were significantly lowe than that fed with artificial feed （P 〈 0.05）. The total protein （TP）, urea nitrogen （UN） and alkaline phosphatase （AKP） of juvenile S. guttatus fed with E. Prolifra were significantly higher than that fed with artificial feed （P 〈0.05）, while glutamic oxalacetie transaminase （AST/GOT） and glutamic-pyruvic transaminase （ALT/GPT） of juvenile S. guttatus fed with E. prolifra were significantly lower than that fed with artificial feed （P 〈 0.05 ）. SOD, GPX and anti-superoxide anion radical activity in liver, kidney, gill and muscle of juvenile S. guttatus fed with E. prolifra were higher than that fed with artificial feed, and these antioxidant enzyme activities in kidney of juvenile S. gtatatus fed with E. prolifra was significantly higher than that fed with artificial feed （P 〈 0.05）, while CAT and hydroxyl radical-inhibiting activity in liver of juvenile S. guttatus fed with arti- ficial feed were significantly higher than that fed with E. prolifra （P 〈 0.05 ）. Juvenile S. guttatus fed with E. prolifra showed poor growth performance but better antioxidant defense system. S. guttatus is easily raised and has stronger ability of digestion and absorption of E. Prolifra. The technique that uses S. gtatatus to control E. prolifra deserves deeply study.

Optimization of dilute acid hydrolysis of Enteromorpha

Acid hydrolysis is a simple and direct way to hydrolyze polysaccharides in biomass into fermentable sugars. To produce fermentable sugars effectively and economically for fuel ethanol, we have investigated the hydrolysis of Enteromorpha using acids that are typically used to hydrolyze biomass： H2SO4, HC1, H3PO4 and C4H404 （maleic acid）. 5%（w/w） Enteromorpha biomass was treated for different times （30, 60, and 90 min） and with different acid concentrations （0.6, 1.0, 1.4, 1.8, and 2.2%, w/w） at 121~C. H2SO4 was the most effective acid in this experiment. We then analyzed the hydrolysis process in H2SO4 in detail using high performance liquid chromatography. At a sulfuric acid concentration of 1.8% and treatment time of 60 min, the yield of ethanol fermentable sugars （glucose and xylose） was high, （230.5 mg/g dry biomass, comprising 175.2 mg/g glucose and 55.3 mg/g xylose）, with 48.6% of total reducing sugars being ethanol fermentable. Therefore, Enteromorpha could be a good candidate for production of fuel ethanol. In future work, the effects of temperature and biomass concentration on hydrolysis, and also the fermentation of the hydrolysates to ethanol fuel should be focused on.