龙须菜(Gracilariopsis)/江蓠(Gracilaria)的生长和种质特性分析

龙须菜(Gracilariopsis lemaneiformis)是具有重要经济价值和生态效益的大型红藻, 主要用作琼胶提取原料和鲍的饵料。本研究利用生理生化、液相色谱-质谱联用和氨基酸分析等方法, 比较了龙须菜(Gp. lemaneiformis) (wt、981、Gl-1、Gl-s、Gl-g)、异枝龙须菜(Gp. heterocla, Gh)和细基江蓠繁枝变种(Gracilaria tenuistipitata var. liu, Gt)的生长及藻胆蛋白、琼胶、红藻糖苷和氨基酸等的差异, 以期为龙须菜/江蓠栽培中的种质区分及选择提供参考。结果表明Gt在23 ℃和30 ℃条件下生长均最快, 其相对生长速率分别为野生型龙须菜(wt)的2.19倍和2.49倍。龙须菜Gl-s中藻胆蛋白浓度最高, 为wt的1.91倍。除了Gt之外, 其余6种藻中琼胶产率较高(16.22%~18.91%)。Gt中红藻糖苷和海藻糖积累最多, 分别为wt的3.50倍和1.81倍。Gl-g、Gl-s、Gt和Gh多糖丰富, 在36.89%~40.23%; 龙须菜981、Gl-1、wt和Gl-s总氨基酸浓度较高, 在152.35~161.32 mg·g^–1干质量之间, 并且981、Gl-1、Gl-s氨基酸评分较优。综合以上结果, 龙须菜981、Gl-1和Gl-s的藻胆蛋白、琼胶和氨基酸等均显著优于其他藻, 并且生长较快, 可用于琼胶、藻胆蛋白及多糖的提取或鲍的饵料; 而细基江蓠繁枝变种生长快、红藻糖苷和海藻糖丰富, 可大规模栽培用作鲍的饵料。该研究为丰富及开发利用中国大型海藻种质资源提供了重要的资料。     

琼胶的研究及进展

近年来有关琼胶研究的趋势主要集中在两个方面：一是有关本国琼胶原料藻的养殖条件和新开发海藻品系提高琼胶产量、质量的研究,其中重点研究琼胶产量、质量的影响因素;另一个就是琼胶及其分级产品琼胶糖在现代生物技术中的应用。１琼胶原料藻的开发和琼胶产量及质量影响因素的研究１．１红藻资源的开发生产琼胶的原料过去一直是以石花菜为主,现墨西哥等国的主要琼胶生产原料依旧是石花菜。后来,发现碱处理可大大改善江蓠琼胶的性能,尤其是石花菜资源被过度开采以及江蓠大面积养殖获得成功之后,江蓠已成为世界范围内生产琼胶的主要原料…     

江蓠属藻胆蛋白的研究──Ⅰ 诱变、突变体筛选及藻胆蛋白的光谱特性

用N-甲基-N′-硝基-N-亚硝基胍（MNNG）对龙须菜配子体进行诱变处理，并筛选出色素突变体。又以真江蓠、细基江篱繁枝变型、龙须菜及其突变体为材料进行了藻胞蛋白的提取、纯化及藻胆蛋白光谱特性的研究。结果表明，江蓠属三个物种藻胆蛋白的含量有明显差异，龙须菜的野生型藻体与突变体之间藻胆蛋白含量的差异比不同物种之间的差异更为显著。江蓠属三个物种中藻胆蛋白的吸收光谱中以藻红蛋白（PE）变化最大：细基江蓠繁枝变型PE的吸收光谱有二峰一肩，属Ⅰ型R-PE，而真江蓠和龙须菜的PE的吸收光谱有三个峰，属Ⅱ型R－PE：龙须菜的不同突变型藻体的吸收光谱也有Ⅰ型和Ⅱ型R－PE之分。不同物种藻蓝蛋白也有R－PC和C－PC的差异，异藻蓝蛋白的吸收光谱及三种藻胆蛋白的荧光发射光谱也略有变化。并以光合进化的观点分析了本文的实验结果。     

福建福宁湾表层沉积物中甲藻孢囊分布与多样性研究

孢囊是甲藻生活史中特殊的休眠阶段,被认为是赤潮发生的种源。于2018年4月采集了福建福宁湾海域表层沉积物,对沉积物中甲藻孢囊的分布规律进行了研究,重点揭示有毒有害甲藻孢囊的分布;同时测定了沉积物中生源要素含量,以揭示孢囊分布与生源要素的关系。共鉴定甲藻孢囊25种,其中别什藻(Biecheleria tirezensis)孢囊占据优势。孢囊的种类多样性指数(H'')偏低,为2.06~2.34;均匀度指数(J)为0.71~0.81。孢囊密度介于178.6~386.3 cysts/g (以干重计,下同),平均为286.0cysts/g。孢囊密度高值区位于水深较深、沉积物颗粒较细的长表岛外海域,而低值区则位于长表岛至海尾角的近岸海域。值得注意的是,研究分析鉴定出9种有毒有害甲藻的孢囊,包括麻痹性贝类毒素(paralytic shellfish poisoning,PSP)原因种奥氏亚历山大藻(Alexandrium ostenfeldii)和链状/塔玛亚历山大藻(Alexandrium catenella/tamarense)孢囊复合体、goniodomine A原因种平野亚历山大藻(Alexandrium hiranoi)、虾夷扇贝毒素(yessotoxin,YTX)原因种具刺膝沟藻(Gonyaulax spinifera)和网状原角藻(Protoceratium reticulatum)、产生鱼毒素的哈曼褐多沟藻(Pheopolykrikos hartmannii)以及赤潮藻类Barrufeta bravensis、锥状斯氏藻(Scrippsiella acuminata)和垂裂莱万藻(Levanderina fissa),其中Barrufeta bravensis、Gonyaulax spinifera和Scrippsiella acuminata的孢囊分布广泛且密度较高,需引起关注。     

泡叶藻及海带藻渣中岩藻聚糖硫酸酯的提取及其抗氧化活性

采用超声波辅助提取方法提取泡叶藻(Ascophyllum mackaii)及海带(Laminaria japonica)藻渣中岩藻聚糖硫酸酯, 以均匀试验设计建立回归模型优化高效制备提取工艺。采用高效凝胶过滤色谱法(HPGPC)进行了相对分子质量检测及理化性质分析; 利用Fenton 反应检测法、邻苯三酚自氧化法等进行了抗氧化活性研究。结果表明, 优化的高效制备技术的超声波最佳条件为超声70 min, 温度为90℃,水提时间2 h, 料液比1︰ 80, 泡叶藻及海带藻渣中岩藻聚糖硫酸酯的高效提取率分别为4.49%和3.69%,分子质量分别为142 kDa 和136 kDa, 泡叶藻和海带藻渣中的岩藻聚糖硫酸酯均具有较好的清除超氧阴离子自由基、羟自由基能力及还原能力。海带的抗氧化活性总体略高于泡叶藻。     

神经毒素BMAA对球等鞭金藻(Isochrysis galbana)的生长抑制作用研究

神经毒素β-N-甲氨基-L-丙氨酸(β-N-methylamino-L-alanine,BMAA)主要来自淡水或海洋环境中的蓝藻和硅藻,在海洋生态系统中具有明显的生物放大作用,被认为是诱发阿尔茨海默症(Alzheimer''s Disease,AD)等多种神经退行性疾病的重要环境因子。近年,BMAA及其同分异构体2,4-二氨基丁酸(2,4-diaminobutyric acid,DAB)在我国及其他多个沿海国家和地区的贝类水产品中被普遍检出,潜在威胁消费者健康和海洋生态安全。但目前有关BMAA对海洋微藻的化学生态学作用尚不清楚。为此,通过向球等鞭金藻(Isochrysis galbana)培养基中分别添加不同浓度的BMAA及20种蛋白氨基酸,探究了BMAA单独及其与氨基酸联合作用96 h对球等鞭金藻比生长率和氨基酸含量的影响,并分析了微藻吸收外源BMAA的含量。结果表明,球等鞭金藻能吸收培养体系中的外源BMAA,吸收量与BMAA的添加浓度呈正相关,且进入细胞内的BMAA多半以溶解结合态形式存在;BMAA抑制批次培养的球等鞭金藻比生长率的96 h半效应浓度(96 h-EC₅₀)约为2 μmol/L;与对照组相比,暴露于BMAA 96 h后球等鞭金藻细胞内酪氨酸、丙氨酸、丝氨酸等15种氨基酸的合成量明显降低;除脯氨酸、苏氨酸、甘氨酸外,其他17种氨基酸与BMAA联合暴露实验均增强了BMAA对球等鞭金藻比生长率的抑制效应,这可能与培养体系中的氨基酸促进了微藻吸收外源BMAA的能力有关。因此,海洋生态系统中BMAA毒素的化学生态学作用应引起人们的关注。有关BMAA抑制球等鞭金藻有丝分裂的分子机制有待进一步研究。     

锰离子对斜生栅藻DHD-3 的生长和油脂积累的调控作用

研究了培养液中不同锰离子浓度对斜生栅藻(Scenedesmus obliquus)DHD-3 的生长、油脂积累以及脂肪酸组成的影响。结果表明, 培养液中不同初始浓度的锰离子对斜生栅藻早期叶绿素积累和生长会产生一定的调节作用, 过高或过低的锰离子都不利于斜生栅藻细胞内叶绿素的积累、微藻的生长和油脂的积累。经过14 d 培养后, 当初始锰离子的添加量为2.72 mg/L 时, 斜生栅藻的生物量和细胞内油脂含量分别达到2.9 g/L 和细胞干重的55.1%, 细胞内油脂含量比对照组提高了11%; 同时, 单位水体中油脂的产量达到了1.6 g/L, 比对照组提高了14%, 但改变锰离子的初始浓度并不对斜生栅藻脂肪酸的组成产生明显影响。     

一株底栖硅藻——双眉藻的优化培养

双眉藻(Amphora sp.)是糙刺参(Stichopus horrens)喜食的优良饵料。本文采用光密度法分别测定了该藻在光照强度28～149 μmol/(m²·s)、温度20～35℃、盐度25~45 和氮质量浓度0～7 500 mg/L、磷质量浓度0～440 mg/L、硅质量浓度0～1 500 mg/L 以及氮磷硅多因子组合情况下的比生长速率, 探讨了光照、温度、盐度和不同质量浓度的氮、磷、硅单因子及多因子组合对该藻生长的影响, 以及该藻的最适生长条件。单因子试验结果表明, 该藻在光照范围为35～149 μmol/(m²·s)时都能良好生长, 最适光照为56～99 μmol/(m²·s), 低温时该藻生长缓慢, 最适生长温度为25～30℃。Amphora sp.为广盐性, 在盐度25～45 都能较好生长, 最适盐度为30～35。氮、磷、硅的最适质量浓度分别是750～7 500 mg/L、44 mg/L和150mg/L, 磷对该藻生长的影响比氮更显著。正交实验结果表明, 氮、磷、硅的最佳质量浓度分别为75 mg/L、44 mg/L 和150 mg/L, 最佳配比为2.4:1:3.4, 与其他底栖硅藻的相应指标存在一定的差异, 可能是物种和地域环境差异引起的, 反映出该藻适应高温、强光特殊栖息环境的特征。     

方斑东风螺3个选育世代遗传多样性和遗传结构的微卫星分析

采用12个多态性微卫星标记对方斑东风螺(Babylonia areolata)泰国选育系TF₄~TF₆连续3代选育群体的遗传多样性与遗传结构进行了分析。3个群体的多态信息含量分别为0.730、0.717和0.708,均高于0.5,表现出较高的多态性。平均等位基因数(A)、有效等位基因数(A_e)、观测杂合度(H_o)、期望杂合度(H_e)和Shannon’s信息指数(I)的变化范围分别为11.667~12.583、6.334~6.915、0.658~0.672、0.737~0.787和1.837~2.003,整体呈降低趋势,但差异并不显著(P>0.05)。分子方差分析结果显示,群体间的遗传变异仅占总变异的0.95%;群体间的遗传分化系数(F_st)介于0.00569~0.01324,处于低等分化水平(F_st<0.05)。主坐标分析和STRUCTURE分析结果显示,3个群体呈现出相似的遗传背景和遗传结构。以上研究结果表明,经过连续多代的人工选育,方斑东风螺选育群体保持着较高的遗传多样性水平,遗传变异和遗传分化水平较低,遗传结构趋于稳定,仍具有较高的遗传选育潜力。     

螺旋藻的藻胆蛋白提取及稳定性研究

对螺旋藻藻胆蛋白提取工艺进行研究，发现低浓度的ＣａＣｌ２溶液低温（４℃）自溶提取效果最好，在提取中，分别以新鲜藻泥和喷雾干燥的藻粉为材料，发现前者的藻胆蛋白得率高于后者，而两者的藻胆蛋白分离纯化后，光谱性质基本相同，稳定性研究结果表明，藻胆蛋白溶液在６０℃下热稳定性较好，在低温避光条件下保存最稳定。     

经济海藻繁育、养殖及综合利用的回顾与展望

经济海藻繁育、养殖及综合利用是海洋农牧业及工业的重要组成部分。20世纪经过几代人的努力,我国在海带、紫菜、裙带菜及龙须菜的繁育、养殖关键技术等方面成功取得突破,为这些海藻的产业化提供坚实的保障,为我国成为世界海藻大国奠定了基础。海藻养殖产业为人们提供了食品、藻胶及其它丰富的产品,这包括保健品、功能食品、化妆品及药物等。海藻养殖产业也对人类经济、社会的发展起到重要作用,通过吸收环境中的二氧化碳、氮和磷,为海洋生态环境的改善发挥了重要作用。本文对我国海藻繁育、养殖及综合开发的历程进行简要回顾,对当前我国、中国科学院海洋研究海藻研究与应用进行了总结,对海藻研究发展的未来进行了展望;适应海藻产业从量向质的方向转变,同时兼顾生态环境效益,为我国海藻研发及应用提供参考。     

牙鲆与夏鲆杂交及回交子代胚胎发育及早期生长比较

通过人工授精技术对牙鲆(Paralichthys olivaceus )和夏鲆( Paralichthys dentatus )进行了正反交及回交实验,并比较了正反交、回交子代的胚胎发育时序和仔稚幼鱼的生长.结果表明:孵化水温18.0±0.5℃下,初孵仔鱼破膜用时为:牙鲆41 h,正交鲆47 h,回交牙鲆42 h30 min,回交夏鲆44 h;16.5±0.5℃下,夏鲆61 h 40 min,反交鲆66 h.正交及两组回交子代在胚胎期均可正常发育.反交子代卵裂期出现异常,仅少数胚胎可以孵化.胚胎孵化后,在1~64日的培养过程中,反交鲆于3~4 d 内全部死亡,回交牙鲆发育至18日龄时全部死亡.正交鲆和回交夏鲆可正常发育,与牙鲆没有明显差别     

外来与乡土红树种间竞争十五年的群落现状与发展趋势

为了探究经过15年种间竞争后的外来无瓣海桑(Sonneratia apetala)与乡土红树植物秋茄(Kandelia obovata)的群落现状与发展趋势,采用样方法对福建省厦门市同安湾典型红树林群落特征开展实地研究。结果表明:(1)无瓣海桑是无瓣海桑群落中的优势种,而秋茄仅在该群落北侧与无瓣海桑少量混交,秋茄+无瓣海桑群落为种植秋茄和无瓣海桑的茂密混交林;(2)调查幼苗天然更新情况中发现,在两个群落中秋茄均有幼苗自然生长,但均未发现无瓣海桑幼苗;(3)生长状况的调查发现,无瓣海桑长势较秋茄差,其倒伏数量和倒伏程度明显比秋茄严重;(4)无瓣海桑在秋茄+无瓣海桑群落中的生长状况优于在无瓣海桑群落,倒伏程度较轻。综上可见,无瓣海桑在福建省厦门市该研究样地及其周边更新成林和扩散困难,未有入侵秋茄群落的优势;无瓣海桑在风浪环境下,较秋茄更易出现倒伏和枯死等不可逆生长现象;红树林种植过程中采用"外来种+乡土种"的模式,可提高整个林分的抗风浪能力,但需注意种植布局规格的合理性,可避免外来速生快长种与乡土种紧邻混交产生较大的种间竞争,减小对乡土种生长的影响。     

Temporal changes and spatial variation of soil oxygen consumption, nitrification and denitrification rates in a tidal salt marsh of the Lagoon of Venice, Italy

The aim of the present study was to investigate seasonal and spatial patterns of soil oxygen consumption, nitrification, denitrification and fluxes of dissolved inorganic nitrogen (DIN) in a tidal salt marsh of the Lagoon of Venice, Italy. In the salt marsh, intact soil cores including overlying water were collected monthly at high tide from April to October in salt marsh creeks and in areas covered by the dominant vegetation, Limonium serotinum. In May, cores were also collected in areas with vegetation dominated by Juncus maritimus and Halimione portulacoides. In laboratory incubations at in situ temperature in the dark, flux rates of oxygen and DIN were monitored in the overlying water of the intact cores. ¹⁵N-nitrate was added to the overlying water and nitrification and denitrification were measured using isotope-dilution and -pairing techniques. The results show that highest soil oxygen consumption coincided with the highest water temperature in June and July. The highest denitrification rates were recorded in spring and autumn coinciding with the highest nitrate concentrations. Soil oxygen consumption and nitrification rates differed between sampling sites, but denitrification rates were similar among the different vegetation types. The highest rates were recorded in areas covered with L. serotinum. Burrowing soil macrofauna enhanced oxygen consumption, nitrification and denitrification in April and May. The data presented in this study indicate high temporal as well as spatial variations in the flux of oxygen and DIN, and nitrogen transformations in the tidal salt marshes of the Venice lagoon during the growth season. The results identify the salt marshes of the Venice lagoon as being metabolically very active ecosystems with a high capacity to process nitrogen.     

缢蛏（Sinonovacula constricta）GST和HSP90基因克隆及其在氨氮胁迫下的表达特征分析

克隆获得缢蛏(Sinonovacula constricta)谷胱甘肽S-转移酶(Sc-GSTσ)和热休克蛋白90(Sc-HSP90)基因的cDNA全长,分析了它们的组织表达差异及其在氨氮胁迫下的表达特征。结果表明,Sc-GSTσ的全长cDNA为1 414 bp,含有639 bp的开放阅读框(Open Reading Frame,ORF),编码212个氨基酸,Sc-GSTσ氨基酸序列与其他物种的GST氨基酸序列同源性为31.88%～43.40%;而Sc-HSP90的全长cDNA为2 752 bp,ORF为2 181 bp,编码726个氨基酸,其氨基酸序列与其他物种HSP90的氨基酸序列同源性为76.77%～87.05%。荧光定量PCR分析发现,Sc-GSTσ和Sc-HSP90在缢蛏各组织中均有表达,两者均在肝胰腺中表达量最高。氨氮胁迫后,Sc-GSTσ和Sc-HSP90 mRNA在肝胰腺中表达均显著上调(p<0.05),表明氨氮胁迫引起机体的应激反应,2个基因可能参与机体解毒或防御过程。但胁迫后期表达量下降推测是机体的防御能力有限,不足以完全保护宿主免受应激诱导的细胞损伤。     

斑节对虾TSG101基因的克隆及表达分析

为探究肿瘤易感基因101(简称TSG101)对斑节对虾(Penaeusmonodon)的免疫应答作用,了解在细菌刺激下斑节对虾的机体发生的变化机制,本研究以哈维弧菌(Vibrioharveyi)和金黄色葡萄球菌(Staphylococcusaureus)为实验组,以磷酸缓冲液(PBS)为对照组,通过荧光定量分析展开对斑节对虾对菌刺激的免疫应答作用。结果显示,斑节对虾的TSG101在各组织中均有表达,在肝胰腺中的表达量最高。在金黄色葡萄球菌刺激下,斑节对虾的TSG101在肝胰腺中的表达量与对照组相比呈极显著上调(P0.01),第12小时的TSG101 mRNA的表达量达到最大(为对照组的21.60倍);在鳃中的表达量与对照组相比呈极显著上调(P0.01),第6小时斑节对虾TSG101的表达量达到最大值(为对照组的3.64倍)。在注射哈维弧菌第9小时,肝胰腺中的PmTSG101 mRNA表达量极显著上调(P0.01)且达到最大(为对照组的2.50倍)。实验结果初步表明,斑节TSG101参与斑节对虾的先天免疫反应,在金黄色葡萄球菌和哈维弧菌的刺激的情况下,该基因RNA水平的表达情况发生明显变化。     

Vertical and horizontal distribution of meiofauna in mangrove sediments in Transkei, southern Africa

The depth-distribution profiles of meiofauna in four transects in the Mngazana River, Transkei were studied during summer 1980. Highest densities [±1000(100 cm³)⁻¹] were encountered within the top 10 cm of the sediment. Nematodes dominated (80%) and the remainder was made up of ciliates, oligochaetes, gastrotrichs, and low numbers of polychaetes, copepods, kinorhynchs and various crustacean larvae. Among chemical parameters Eh correlated most consistantly with distribution, particularly at the lower tidal levels. Temperature and pH appeared to be of lesser importance. The maximum estimated depth of penetration was on average 72 cm at the HW levels; 32 at MW and 23 at LW. The mean dry biomass was estimated at 1073 mg m⁻²; 941 mg m⁻² and 196 mg m⁻² at these tidal levels respectively. The importance of preliminary studies designed to estimate the depth distribution of meiofauna is discussed.     

Tissue Cu, Fe and Mn concentrations in different-aged and different functional thallus regions of three brown algae from western Ireland

Copper and iron concentrations in three brown algae, Ascophyllum nodosum, Fucus vesiculosus and Laminaria digitata (and additionally Mn in L. digitata) from the Irish west coast were determined using flame atomic absorption spectrophotometry. Metal concentrations in the three species were indicative of prevailing bioavailable metal concentrations in situ but varied greatly between functional tissue parts, between sites and over time. Cu concentrations in actively growing tips of A. nodosum decreased over a 4-month period during autumn/winter, while Fe concentrations increased. Both Fe and Cu concentrations in different thallus sections of A. nodosum and F. vesiculosus increased with increasing age of thallus part in a clean site, but there was no consistent trend for F. vesiculosus from an industrialized site. Within sites, concentrations of all Cu and Fe were similar in both fucoids, but concentrations at the industrialized site were about twice as high as at the pristine site. In L. digitata, all three metals were highest in holdfasts, but had distinctly different distribution patterns in stipes and blade sections, which were most likely related to growth pattern and tissue function. Fe was lowest in meristematic and young blade regions, suggesting small-scale Fe limitation in actively growing tissue. Mn concentrations were higher in distal blade sections than in stipes, and Cu concentrations were highest in meristematic and young thallus parts.     

Propagation and growth of Ponnotheres pholadis living in mantle cavity of Hiatula acuta

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Induction of phenol-type sulfotransferase and glucuronosyltransferase in channel catfish and mummichog

Conjugation of phenolic xenobiotics and metabolites through sulfation and glucuronidation is an important biotransformation pathway. Sulfotransferases (SULT) are generally considered non-inducible, while some UDP-glucuronosyltransferase (UGT) isoenzymes are co-induced with cytochrome P450-1A by Ah-receptor ligands. To test these assumptions for two fish species, we measured sulfation and glucuronidation of 9-hydroxybenzo[a]pyrene in 3-methylcholanthrene (3-MC) treated channel catfish (Ictalurus punctatus) and in mummichog (Fundulus heteroclitus) from the creosote contaminated Atlantic Wood site in the Elizabeth River, VA. The results show a significant induction of both UGT and SULT activity in 3-MC treated catfish, linked to the expected induction of EROD activity. In mummichog, significant induction of UGT was measured at the contaminated site over the reference site (King's Creek, VA), as well as extremely low SULT activities at both sites. Western blots, using a polyclonal antibody for catfish phenol-type SULT, confirmed the absence of phenol-type SULT in mummichog. Residual, though slightly inducible, SULT activity may be attributed to other SULT isoforms.