浒苔多糖的分级纯化及保湿活性研究

用DEAE-Sepharose FF离子交换凝胶层析柱对浒苔(Enteromorpha)多糖进行分级纯化,利用HPLC色谱分析了单糖组成,并以甘油和透明质酸为对照,研究其吸湿和保湿活性。结果表明,浒苔多糖主要为葡萄糖醛酸-鼠李糖-木糖-甘露糖聚合物;浒苔多糖主要由两种组分组成,其一组分木糖和鼠李糖含量摩尔比为1.11:1,另一组分木糖和鼠李糖含量比为1:3.28;浒苔多糖具有与透明质酸相似的吸湿和保湿能力。     

4种不同来源浒苔中多糖的提取分离及理化性质

为探讨不同季节以及不同地点采集的浒苔其多糖理化性质差异,采用水提醇沉法对黄海海域青岛沿海春(原料1)秋(原料3)两季采集的浒苔、2008年夏季爆发浒苔(原料2)以及东海海域福建沿海采集的浒苔(原料4)的多糖进行了提取,得到了4种冷水提取多糖PC1-4和4种热水提取多糖PH1-4。分别对8种浒苔多糖利用Q-Sepharose Fast Flow离子交换色谱法纯化后得到了12个组分。对各组分的总糖含量、糖醛酸含量、硫酸根含量以及蛋白含量进行了测定,利用气相色谱法测定了单糖组成,结果显示不同季节不同海域采集样品的化学组成及单糖组成不同。     

紫菜纳豆菌发酵物中醇提物和多糖生物活性的初步研究

纳豆菌(Bacillus natto)发酵后的条斑紫菜经稀释、离心后上清液用一定浓度的乙醇处理获得醇沉物和醇溶液。将醇沉物去蛋白得到粗多糖,进行抗氧化活性的研究;将醇溶液旋转蒸发得到浸膏,将浸膏按极性大小分相萃取分别得到石油醚相、乙酸乙酯相和正丁醇相浸膏,探讨分相浸膏对金黄色葡萄球菌、枯草芽孢杆菌、四联微球菌的抑菌效果。通过测定多糖和分相浸膏对羟自由基(·OH)和DPPH自由基的清除能力评价其抗氧化能力。结果表明:醇溶物对金黄色葡萄球菌具有抑制作用,且随着浓度的升高各相浸膏对羟基自由基的清除率随之升高,其中,正丁醇相浸膏在质量浓度为0.5 mg/m L时对羟自由基的清除率达到91.6%,说明条斑紫菜经纳豆菌发酵可能产生了活性化合物;与对照组相比,利用纳豆菌发酵紫菜发酵物中多糖提取率增加了0.24%,发酵得到的多糖在质量浓度为5.0 mg/m L时对羟自由基的清除率达到了95.7%。     

不同磷酸根含量的孔石莼多糖体外抗氧化活性研究

利用多糖结构修饰原理,制备磷酸化孔石莼(Ulva pertusa)多糖(PU),并对其进行体外抗氧化活性研究。将多聚磷酸钠与三偏磷酸钠混合后作为磷酸化反应试剂,与孔石莼多糖U反应制备不同磷酸根含量的孔石莼多糖PU。通过磷元素含量分析,确定成功制备不同磷酸根含量的孔石莼多糖衍生物PU,并测定不同磷酸根含量的孔石莼多糖PU与孔石莼多糖U对羟自由基、超氧阴离子清除能力以及金属螯合能力。实验发现通过本方法制备得到的PU6磷酸根含量最高为10.47%。综上所述,不同磷酸根含量的孔石莼多糖体外抗氧化活性不同,与孔石莼多糖U相比,磷酸根含量最高的PU6表现出最强的羟自由基清除作用。在100μg/mL多糖浓度下, PU6表现出最强的金属鳌合能力。     

羊栖菜多糖的提取和抗氧化活性研究

羊栖菜(Sargassum fusiforme)是一种有"长寿菜"美誉的经济藻类,其中的多糖成分具有良好的抗氧化活性。本文依次用冷水和热水处理羊栖菜藻粉,得到两种多糖:冷水浸提多糖(SFCP)和热水煮提多糖(SFHP);随后对这两种多糖的理化性质进行比较,并通过测定二者对DPPH和羟自由基的清除能力评价其抗氧化活性。结果表明,两种多糖都是含有硫酸根的岩藻聚糖,但是SFCP中糖醛酸含量较高,分子质量分布集中,而SFHP中硫酸根含量较多,分子质量分布较宽,且二者硫酸根取代位置不同。两种多糖对DPPH和羟自由基均有一定的清除效果,且清除率与浓度存在剂量依赖关系。相比较而言,SFCP对自由基的清除效率较好。     

氮磷营养盐对浒苔生长影响的初步探讨

在实验室条件下,设置不同的N、P浓度,研究单因子(P:30μmol/L,N:0～500μmol/L和N:500μmol/L,P:0～30μmol/L)对浒苔(Enteromorpha prolifera)生长的影响。结果表明:在高N、P浓度(N:500μmol/L,P:30μmol/L)条件下浒苔生长态势最好,具有较高的相对生长率(0.451)。添加N可以明显促进浒苔的生长,而且随着添加N浓度的提高促进作用增强,浒苔的相对生长率有较大幅度提高。添加P对浒苔的生长也具有一定的促进作用,但促进作用不如添加N的明显;随着添加P浓度的提高,浒苔的相对生长率提高幅度不大,这说明浒苔生长对N变化更为敏感。     

浒苔多糖纺丝性能的探索性研究

在对浒苔多糖溶液的流变性质以及对浒苔多糖膜的外观形态、力学拉伸性能和亲水疏水性等方面研究的基础上,采用注射器喷丝,对浒苔多糖的成纤性做了探索,结果表明,热水法提取的浒苔多糖可以用BaCl2做凝固浴经湿法纺丝制得浒苔纤维。     

超声波辅助提取RP-HPLC法测定浒苔中的叶绿素a、b

建立了一种反相高效液相色谱法(RP-HPLC)测定浒苔(Enteromorpha prolifera)中叶绿素a和b含量。采用的色谱条件:Diamonsil-C18(4.6mm×150mm)柱,流动相为甲醇(含0.2%的乙酸)和丙酮,梯度洗脱,流速为0.8mL/min,进样量10μL,检测波长430nm。在此条件下,叶绿素a和叶绿素b与浒苔中的其他化合物分离良好,叶绿素a、b质量浓度为0.50～500mg/L具有良好的线性关系(R2=0.9999),能对浒苔提取液中的叶绿素a、b进行准确定量。     

响应面法优化浒苔半纤维素的提取条件及其组分分析

以浒苔(Enteromorpha prolifera)为原料,采用响应面法优化碱性过氧化氢提取半纤维素的条件。在单因素实验的基础上,运用Box-Benhnken中心组合原理,设计四因素三水平实验,确定半纤维素最佳提取条件。采用红外光谱(FT-IR)和离子色谱(IC)分析浒苔半纤维素组分。结果表明,各因素对浒苔半纤维的提取率的影响为:时间温度料液比氢氧化钠浓度。碱性过氧化氢法提取半纤维素的最佳条件为:氢氧化钠浓度为4.8 g/L,提取温度为92℃,提取时间为5 h,料液比1︰70,半纤维素的提取率为56.75%,与预测值57.30%基本一致。FT-IR结果显示,浒苔半纤维素红外吸收光谱中含有明显的木糖和阿拉伯糖的特征吸收峰,为吡喃环结构,由β-糖苷键连接。离子色谱结果表明,浒苔半纤维素主要由木糖和阿拉伯糖组成,含有少量葡萄糖和半乳糖。木糖含量为54.4%,其次为阿拉伯糖,含量为15.3%,葡萄糖和半乳糖含量分别为5.6%和2.7%。     

2017年绿潮浒苔(Ulva prolifera)生理特征及孢子囊形成情况分析

近几年来在我国青岛海域连续暴发的浒苔绿潮造成了巨大的经济损失并且破坏了近海海洋生态系统平衡。因此,浒苔绿潮受到了越来越多的关注。本研究重点关注了绿潮暴发期间不同海域浒苔藻体生理特征和孢子囊形成情况。研究发现,不同海域里浒苔藻体生理特征差异显著,孢子囊比例显著不同,并且观察到漂浮浒苔的原位萌发。2017年5月中旬,我们在苏北浅滩紫菜养殖区域(33.78°N,121.29°E)对筏架绠绳上生长的绿藻,退潮后滩涂散落的绿藻和涨潮时海面上漂浮的绿藻进行为期5天的野外采集。另外,在2017年6月随科考船对浒苔暴发海域的浒苔样本进行采集。采集范围在(33.5°—36.5°N, 120°—124°E)。结果表明,从低纬度到高纬度,浒苔F_v/F_m(光系统Ⅱ最大光化学量子产量)值从0.65逐渐降低至0.3左右;YⅡ(光系统Ⅱ实时光化学量子产量)值也从最高0.5左右降低至最低0.1。此外,定生浒苔F_v/F_m值为0.6—0.8左右,明显高于漂浮浒苔; YⅡ值也有类似趋势。在孢子囊形成比例方面,定生浒苔约有5%藻体形成了孢子囊,而漂浮浒苔中孢子囊形成比例达到20%。数据表明,低纬度区域为浒苔来源地,浒苔生理活性良好,孢子囊形成比例低。随着浒苔往北漂移,其生理活性降低。并且,漂浮浒苔孢子囊形成比例显著性高于定生浒苔。本文认为,浒苔脱离来源区后,孢子囊的快速形成、成熟和孢子释放以及孢子的原位萌发是浒苔生物量激增的重要原因。     

Enteromorpha and the cycling of nitrogen in a small estuary

The nitrogen relations of Enteromorpha spp. growing on intertidal mud flats have been examined over a twelve-month period. Nitrogen assimilation rates using ¹⁵N have been used to calculate the production of the alga and were between 0·046 and 0·217 mg $\text{NH}{}_4{}^{\mathrm{+}}\text{N}$ (g dry wt alga)^?1 h^?1 A considerable quantity of the alga was buried beneath the sediment over the growth season and was calculated to be equivalent to an input of up to 9·52 g N m^?2 per month and 32 g N m^?2 over one complete growth season. Based on carbon, this latter value represented an input of approximately 320 g C m^?2 annually. Low rates of nitrogenase activity (acetylene reduction) were found to be associated with the Enteromorpha. The organisms responsible for the nitrogenase activity were probably heterotrophic bacteria but they did not contribute significant quantities of nitrogen to the alga.     

Trophic Potential and Photoecology of Endolithic Algae Living within Coral Skeletons

Abstract. The biomass of the endolithic algae Ostreobium quekettii Phyllosiphoniaceae living within skeletons of the scleractinans Mycedium elephantotus and Leptoseris fragilis averages 300 μg protein. cm^-2. This represents approximately 7% of the protein of the zooxanthekie-containing tissue of M. elephantotus and approximately 38% of that of L. fragilis. Oxygen production Pmax_net of 0. querkettii in bare skeletons of M. elephantotus averaged 0.7 μg O₂.cm^-2· h^-1 measured in large skeletal fragments. This amount is approximately 6% of the productivity of the zooxanthellae Symbiodinium microadriaticum living in the same scleractinian species at the same depth Pmax_net 11 μg O₂· Cm^-2· h^-1. Light compensation of O. quekettii - within skeletons - was reached at approximately 10 and saturation at 35 40 μE·m^-2· s^-1. Algae within the M. elephantotus skeletons receive a maximum of 4–6% of the ambient irradiance, which is approximately 0.9 μE · m^-2· s^-1 approximately 0.04% surface irradiance at a depth of 88 m. In L. fragilis at a depth of 145 m, the photon flux decreases to 0.3 μE·m^-2· s^-1, which is less than 0.004% of surface intensity. With increasing depth, the ratio of Chl b to Chl a increased in endolithic algae colonizing L. fragilis, indicating improvement of light harvesting under low light conditions. In free-living O. quekettii cultured at irradiance levels from 0.5–60 μE·m^-2· s^-1, the concentrations of chlorophylls increased and that of siphonein and β-carotene decreased with decreasing photon flux.     

海上围隔进行羟基杀灭赤潮生物的研究

采用强电场电离H2O、O2方法,在分子层次上加工成高浓度羟基自由基(OH.)溶液,喷洒在有赤潮生物的海面上,当海水的羟基质量浓度达到0.68 mg/L时,致死洛氏角刺藻(Chaetoceros lorenzianus)等31种赤潮生物效率达到99.89%,致死细菌、弧菌效率达到100%,致死膝沟藻孢囊、多甲藻孢囊效率达到100%;赤潮生物叶绿素a含量低于检测方法低限值;剩余OH.分解成H2O和O2;尸体将分解成CO2、H2O和微量无机盐。从试验数据表明,OH.是治理赤潮有效可行的绿色新方法。实现了治理赤潮以及加工羟基过程的零污染、零废物排放、零残留物。     

Productivity of dinoflagellate blooms on the west coast of South Africa,as measured by natural fluorescence

The biomass and productivity of phytoplankton populations inshore on the west coast of South Africa were investigated towards the end of the upwelling season, a period when high-biomass dinoflagellate blooms are common. Productivity was estimated from natural fluorescence measurements (P_NF ), using photosynthesis (P) v. irradiance (E) relationships (P_E ) and by means of the in situ ¹⁴C-method (P_C ) A linear regression of P_NF productivity against P_C and P_E productivities yielded a slope of 0.911 and an r ₂ of 0.83 (n = 41). Physical and biological variability was high inshore, reflecting alternating periods of upwelling and quiescence. Mean chlorophyll inshore (within a 12 m water column) ranged from 0.7 to 57.8 (mean = 8.9) mg·m^&minus3, mean P_NF productivity ranged from 8.4 to 51.0 (mean = 24.6) mgC·m^?3·h^?1 and daily integral P_NF productivity from 0.8 to 4.8 (mean = 2.3) gC·m^?2·day^?l. Transects sampled during active and relaxation phases of upwelling had different chlorophyll distributions. High chlorophyll concentrations (sometimes >50 mg·m^?3) were associated with surface blooms within the region of the upwelling front. Estimates of daily water-column P_NF productivity within these frontal blooms ranged from 4.0 to 5.6 gC·m^?2·day^?1. With relaxation of wind stress, blooms dominated by dinoflagellates flooded shorewards and often formed red tides. Chlorophyll concentrations of > 175 mg·m^?3 and productivity rates > 500 mgC·m^?3·h^?1 and 12 gC·m^?2·day^?1 were measured during a particularly intense red tide. Offshore, the water column was highly stratified with a well-defined subsurface chlorophyll maximum layer within the pycnocline region. Estimates of daily water-column P_NF productivity ranged from 2.4 to 4.0 gC·m^?2·day^?1 offshore. The high productivity of shelf waters on the West Coast in late summer can be ascribed largely to dinoflagellate populations and their success in both upwelling systems and stratified conditions.     

Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution. II. Formation constants for the monosilicate ions SiO(OH)3 and SiO2(OH)2. A precision study at 25°C in a simplified seawater medium

The hydrolysis of silicic acid, Si(OH)₄, was studied in a simplified seawater medium (0.6 M Na(Cl)) at 25°C. The measurements were performed as potentiometric titrations (hydrogen electrode) in which OH⁻ was generated coulometrically. The total concentration of Si(OH)₄, B, and log[H⁺] were varied within the limits 0.00075 B 0.008 M and 2.5 -log[H⁺] 11.7, respectively. Within these ranges the formation of SiO(OH)₃⁻ and SiO₂(OH)₂²⁻ with formation constants log β₋₁₁(Si(OH)₄ SiO(OH)₃⁻ + H⁺) = −9.472 ±0.002 and log β₋₂₁(Si(OH)₄ SiO₂(OH)₂²⁻ + 2H⁺) = −22.07 ± 0.01 was established. With B > 0.003 M polysilicate complexes are formed, however, with -log[H⁺] 10.7 their formation does not significantly affect the evaluated formation constants. Data were analyzed with the least squares computer program LETAGROPVRID.     

The mutagenicity of acid digests from several common marine macroalgae (Fucus serratus,Porphyra umbilicalis,Enteromorpha spp.)

Acid digests of three common marine macroalgae (Fucus serratus, Enteromorpha spp., Porphyra umbilicalis) exhibit substantial mutagenic activity for Salmonella typhimurium strains TA98 and TA100 in the microtire fluctuation test. Although these algae are known to concentrate heavy metals, the mutagen(s) is probably an organic compound(s).Collections of these three marine macroalgae were made along the Gower coast of Wales, Great Britain, at distances between 8·0 and 32·0 km from the industrial center of Swansea-Port Talbot. When tested for mutagenicity with TA98, the acid digests of F. serratus and Enteromorpha spp. showed an inverse relationship between activity and distance from Swansea-Port Talbot. This relationship was not observed with P. umbilicalis or with any of the digests when tested with TA100.These data are consistent with the hypothesis that Swansea-Port Talbot is a point emitter for contaminants which are mutagenic for TA98 and are accumulated by Enteromorpha and Fucus.     

Biological parameters reflecting the current state of the exploited pink dentex Dentex gibbosus (Pisces: Sparidae) population off the Canary Islands

A total of 639 pink dentex Dentex gibbosus was collected in Canary Islands waters between April 1991 and September 1993. Total lengths ranged from 14,2 to 95,2 cm. Females dominated smaller size-classes and males the larger ones. The species was characterized by protogynous hermaphroditism. The overall ratio of males to females was 1 : 1,45. The reproductive period extended from April to September, spawning peaking in June/July. The total lengths at 50% maturity were 34,7 cm for females and 38,6 cm for males. The length-mass relationship for the whole sample can be described by the parameters a = 0,01014 and b = 3,0812. Fish aged 0–16 years were present in the samples. The parameters of the Von Bertalanffy growth equation were: L _∞ = 101,2 cm, k = 0,149·year^?1, and t ₀ = ?0,111 years. The rates of total mortality Z and natural mortality M were 0,57 and 0,28·year^?1 respectively. Rates of fishing mortality F and exploitation E were 0,29 and 0,51·year^?1 respectively. The estimated length at first capture (LC ₅₀) was 17,8 cm total length.     

Use of Cell-Specific PAM-Fluorometry to Characterize Host Shading in the Epiphytic Dinoflagellate Gambierdiscus toxicus

Abstract. Cell‐specific fluorescence characteristics were used to characterize the light tolerance of the toxic benthic dinoflagellate Gambierdiscus toxicus. The fluorescence parameter F_v : F_m was measured using pulse amplitude modulation (PAM) fluorometry on individual cells collected from foliose red algae growing in the sub‐tidal margin of South Water Cay, Belize. Samples were collected over several days during sunny and cloudy conditions and compared to samples incubated in situ. The data from individual cells were used to generate both F_v : F_m frequency histograms and averages. Maximum individual cell values of F_v : F_m reached 0.81 in pre‐dawn samples, a value near the theoretical maximum for PAM fluorometry. In field samples from macroalgal hosts, average F_v : F_m values declined only slightly during the day, but cells incubated in bottles under 47 % incident sunlight showed a significant mid‐day depression. In freshly collected samples, near‐maximum F_v : F_m values could be found in individual cells during the entire day; however, the frequency histograms indicated a greater range in F_v : F_m values during the afternoon than in the morning. In contrast, cultures of G. toxicus showed a tight distribution around a mean. Field samples showed a rapid recovery to near‐maximum F_v : F_m within 2 min when assayed using a standardized actinic light series. Similar results were obtained in laboratory cultures of G. toxicus grown at 73 µmol photons · m^‐2 · s^‐1, but not at 383 µmol photons · m^‐2 · s^‐1. These data provide empirical support for suggestions that G. toxicus exploits the three‐dimensional structure of the algal host thallus to minimize light exposure. This strategy permits G. toxicus, a high‐light intolerant species in culture, to thrive in shallow, well‐lit tropical seas. It may also partially explain the observed preference of G. toxicus for complex, foliose macroalgae as hosts.     

Benzo[a]pyrene-dione-stimulated oxyradical production by microsomes of digestive gland of the common mussel, Mytilus edulis L

The potential of benzo[ a]pyrene (BaP) quinones (diones) to stimulate NAD(P)H-dependent hydroxyl radical (·OH) production (2-keto-4-methiolbutyric acid (KMBA) oxidation) by digestive gland microsomes of M. edulis was studied using iron/EDTA as a promotor of the Haber-Weiss reaction (O₂⁻ + H₂O₂ = ·OH + OH⁻ + O₂). Stimulation of basal rates of KMBA oxidation was observed for all three diones. Stimulation was similar for the 1,6- and 3,6-diones, but much less for the 6,12-dione, and greater for the NADH than the NADPH-dependent reaction, viz. % increases of 78 to 333 (NADH) compared to 0 to 78 (NADPH). Maximal KMBA oxidation was obtained at dione concentrations of 12.5 to 50 μm. Inhibition of KMBA oxidation by Superoxide dismutase and catalase indicated the involvement of respectively Superoxide anion radical (O₂⁻) and hydrogen peroxide (H₂O₂) in 1,6-dione stimulated NADPH-dependent · OH formation. The apparent K_m values of xenobiotic-stimulated KMBA oxidation were lower for BaP-diones than for the model redox cycling quinone menadione (2-methyl-1,4-naphthoquinone), viz. in μm, 0.6 to 14.6 (NADH) and 4.4 to 28.5 (NADPH) compared to 315 to 457 (NADH) and 72 to 103 (NADPH). The results are consistent with metabolism of BaP to diones and resultant enhanced generation of oxyradicals being a potential mechanism of pollutant-mediated toxicity in molluscs.