Cytotoxic constituents in the holdfast of cultivated Laminaria japonica

ABSTRACT:     Four steroidal ketones were isolated from the holdfast of cultivated Laminaria japonica . The structures were characterized as ergosta-4,24(28)-diene-3-one (1), ergosta-4,24(28)-diene-3,6-dione (2), stigmasta-4,24(28)-diene-3-one (3) and stigmasta-4,24(28)-diene-3,6-dione (4), by spectral data. Compounds 2 and 4 were shown to be cytotoxic against the MCF-7 human breast cancer cell, and the growth of MCF-7 was inhibited by 96% and 79%, respectively, at 10 µg/mL. It is the first report on the isolation of cytotoxic steroidal ketones from the kelp in the genus of Laminaria.     

Physiological differences between the nutrient uptakes of Kjellmaniella crassifolia and Laminaria japonica (Phaeophyceae)

SUMMARY: The nutrient uptake kinetics of Kjellmaniella crassifolia and Laminaria japonica were determined under a variety of conditions. The nitrate and phosphate uptake rates followed Michaelis–Menten kinetics toward ambient nutrient concentrations, showing no difference between the maximum uptake rates of the two species. However, half-saturations of nitrate and phosphate uptake kinetics in K. crassifolia were higher than those in L. japonica . Low water temperature (5°C) greatly restrained the nitrate and phosphate uptakes of both algae. Low irradiance (< 100 μE/m² per s) restrained nitrate and phosphate uptakes only in L. japonica , although high irradiance (> 100 μE/m² per s) caused no difference between the two species. The nitrate and phosphate uptake rates at low irradiance in K. crassifolia were 2–7 times higher than those in L. japonica . Light compensation and saturation irradiances in K. crassifolia were significantly lower than in L. japonica . These results indicate that K. crassifolia is able to take up carbon and nutrients at low irradiance, which suggests that the nutrient uptake characteristic of K. crassifolia could allow it to adapt to deeper habitats and even to high water turbidity.     

花鳗、欧鳗和日本鳗肌肉无机元素的分析

采用电感耦合等等子体发射光谱仪对花鳗、欧鳗和日本鳗肌肉无机元素组成进行了测定。结果表明:花鳗肌肉中Ca含量最高,P含量次之。欧鳗和日本鳗肌肉中P含量最高,Ca含量次之。三种鳗鲡肌肉中Na、Mg、K含量相近且高低顺序相同,花鳗肌肉中常量元素和Zn、Fe、Mn的含量均高于欧鳗和日本鳗。三种鳗鲡肌肉中均含人体不可缺少的微量元素Zn。据此可认为花鳗营养价值最高。     

海带褐藻糖胶的研究

本工作研究了我国人工养殖的海带叶片中褐藻糖的分布，及海带综合利用工业的废料碱凝沉物中褐藻糖胶的存在量和分离条件。海带叶片中的褐藻糖含量分布边缘比中部多，并从基部向尖部增加，即由0．3％增至1％以上。试验了用十六烷氯化吡啶法(CPC法)和乙醇沉淀法从碱凝沉物中分离褐藻糖胶的条件。两种方法的褐藻糖胶获得率分别为5．6％和4．4％(对干碱凝沉物)，其中的褐藻糖含量分别为24．7％和28．7％。碱凝沉物中的褐藻糖含量为1．4～3．5％。还研究了从褐藻糖胶以酸水解制取褐藻糖的诸条件，并分离出纸层析纯的褐藻糖结晶。     

Effects of light quality on the reproduction and morphology of sporophytes of Laminaria japonica (Phaeophyceae)

Responses of the sporophytes of Laminaria japonica to blue, red and white lights were investigated using segments, discs and whole plants. The relative growth rate with regard to the blade's length and width showed no difference among the light conditions during 2 weeks of culturing. On the contrary, the elongation rates of the stipe and the holdfast were 1.7–2.5 times higher under red light than that under white light as a control. Callus formation in the segments was also promoted more under red light conditions than under white or blue light. Blue light irradiation resulted in a 48% and 12% decrease in the relative growth rate of the stipe and the holdfast, respectively, in comparison with the control. When sporophyte discs were cultured for 10 weeks, all discs formed zoosporangial sori 2–3 weeks earlier under blue light than under white light. However, red light inhibited the formation of zoosporangia. Indoleacetic acid (IAA) oxidase activity was about two‐fold higher under blue light than under red light, suggesting that the difference in response between the blue and red light conditions is related to the internal IAA level of the tissues. The developmental, reproductive and morphological effects of blue and red lights will be useful for the artificial control of the life cycle of Laminaria plants and for the development of more efficient cultivation techniques.     

光质对海带幼孢子体生长和假根发育的影响

以海带Laminaria japonica幼孢子体为材料,比较了不同光质（白光、红光和蓝光）对其生长的影响,并对假根的发育进行了研究。在为期56d的培养期内,蓝光始终促进幼孢子体的生长,平均叶片大小为9530±125μm长/1350±49μm宽,是对照白光组的4倍之多（2200±56μm长/356±20μm宽）;而红光下,藻体生长极为缓慢,叶片大小仅为580±63μm长/135±11μm宽。但是三光质下,藻体假根生长差异较小;假根长/叶片长为红光下最大,蓝光下最小,三光质下该比值均随着培养时间的延长而下降。由于海带的主要捕光色素之一岩藻黄素的吸收峰位于蓝光区,因此加大环境中蓝光的辐射可有效提高光能利用率,从而提高实际光合效率,加快藻体的生长;而假根部由于结构和功能特性,光合能力有所退化,对光质差异不敏感,因而在三光质下的生长相似。     

不同方式加工海带投喂盘鲍幼鲍生长速度比较

将初始壳长1.890.20cm的盘鲍幼鲍随机分配到3个试验组,每组50只,每个试验组各设4个平行组。第1组:投喂盐渍海带;第2组:投喂煮沸海带;第3组(对照组):投喂晒干海带。试验用鲍在同一口水泥池中饲养50d,投喂足量饵料。投喂盐渍海带盘鲍幼鲍的日均壳长增长(P<0.001)及平体重增长率(P<0.05)均明显高于对照组,但投喂煮沸海带盘鲍幼鲍的日均壳长增(P>0.05)及平均体重增长率(P>0.05)与对照组无明显差异。     

大型海藻对氮磷吸收能力的初步研究

实验选取了经济价值较高、生态特征较为明显且研究较为深入的三种大型海藻:海带(Laminaria japonica Aresch)、鼠尾藻(Sargassum thunbergii)和龙须菜(Gracilaria lemaneiformis)作为实验材料,在模拟自然环境条件(14℃、1500lx)和适宜的氮、磷浓度(50μmol/L、5μmol/L)下,研究其在72h内对氮、磷的吸收能力。实验数据测得,海带、鼠尾藻和龙须菜对氨氮吸收速率分别为0.397μmol/g·h、0.317μmol/g·h和0.300μmol/g·h,吸收效率为66.3%、53.6%和51.2%;对磷的吸收速率分别为0.036μmol/g·h、0.030μmol/g·h和0.033μmol/g·h,吸收效率为65.2%、55.7%和58.8%。结果表明,三种海藻对氮、磷均有明显的吸收效果,吸收能力顺序为:海带>龙须菜>鼠尾藻。     

褐藻酸降解菌对海带配子体克隆的作用及其药物防治研究

通过回染实验，确认褐藻酸降解菌是海带配子体克隆病害的主要致病菌；观察了对其海带配子体克隆细胞侵染的现象，并研究了抗生素对海带配子体克隆细胞和褐藻酸降解菌的作用，发现0．5－100mg/L青霉素对配子体克隆细胞的生长有一定促进作用，实验范围内各浓度青霉素对褐藻酸降解菌均有较好的抑菌效果，且抑菌效果随浓度的提高而加强。其中100mg/L青霉素10d内可将褐藻酸降解菌浓度降低到初始浓度的1／20以下，可作为海带配子体克隆保存中有效的抑菌药物。     

海带岩藻聚糖硫酸酯电渗析分离工艺

采用电渗析法对盐沉后的海带酶解液中岩藻聚糖硫酸酯进行分离,探索工业化分离生产岩藻聚糖硫酸酯的方法,以解决目前乙醇沉淀法存在的安全性和高成本等问题。以脱盐率、糖保留率为检测指标,采用响应面法优化了电渗析工艺参数。结果显示,在操作电压80 V、料液流量3.2 L/min、固形物浓度10 mg/ml、p H=5的条件下,电渗析连续循环3次,海带酶液解干基中多糖含量由40.17%提高至47.11%,硫酸根含量由3.36%提高至4.97%。电渗析后海带酶解液干基中的金属离子含量为Ca 0.13 mg/g、Mg 16.04μg/g、Cu 0.29μg/g、Se 11.7μg/g、Cr 8.06μg/g,Pb未检出,较电渗析前均有降低。电渗析对脱除褐藻胶的海带酶解液进行脱盐纯化处理,可有效地分离纯化出岩藻聚糖硫酸酯。     

Assessing the usefulness of otolith elemental compositions for evaluating the population structure of the Pacific herring <Emphasis Type="Italic">Clupea pallasii</Emphasis> in northern Japan

The present study examined whether the elemental compositions of whole otoliths and chronological transect profiles of otoliths covering the complete life history are useful for evaluating the population structure of Pacific herring. Eight elemental ratios, Li:Ca, Na:Ca, Mg:Ca, K:Ca, Mn:Ca, Cu:Ca, Sr:Ca, and Ba:Ca, were measured in whole otoliths and in a series of ablations across the life-history transects by laser ablation inductively coupled plasma mass spectrometry. We studied fish from three sample groups collected from Lake Obuchinuma, Miyako Bay, and Akkeshi Bay of northern Japan from March to May 2008. Significant differences were found in the Na:Ca, Mg:Ca, P:Ca, K:Ca, Mn:Ca, and Ba:Ca ratios of the whole otoliths and in the Li:Ca, Na:Ca, K:Ca, Mn:Ca, Sr:Ca, and Ba:Ca ratios of the otolith core among the three sample groups. Therefore, the present study showed clear differences in elemental composition among the three sample groups from different locations, suggesting that otolith elemental compositions reflect the habitats experienced by individual fish.     

海带种质特征

系统地研究了海带(Laminaria japonica Aresch.)的种质特征。详细地描述了海带的形态构造、生活周期与繁殖、特殊物质及含量、鲜干比、同工酶、分子标记等方面特征，确定了海带物种特征的指标范围，为海带种质检测和鉴定提供了技术参考指标。     

几种饲料原料对刺参幼参生长和体成分的影响

研究了不同饲料原料对刺参Apostichopus japonicus(Selenka)幼参生长和体成分的影响.实验采用鱼粉、鼠尾藻Sargassum thunbergii Kuntze、浒苔Enteromorpha prolifera、海带Laminaria japonica和海泥5种主要原料配制的饲料投喂体长为4.18±0.23cm、体重为5.99±0.26g的刺参幼参,进行了为期80d的养殖实验.实验结束时,投喂鼠尾藻饲料、浒苔饲料和动物性饲料的刺参特定生长率(SGR)分别为95.36%/d、92.29%/d和84.87%/d.这三者之间无显著差异,但生长效果要好于投喂海带饲料和海泥饲料的刺参.实验结果表明,在特定的室内养殖条件下,虽然刺参能够更好地利用植物性蛋白,但是可以将动物性蛋白作为刺参的辅助性饲料成分,配制出营养更全面的配合饲料;浒苔作为刺参幼参的养殖饲料原料是完全可行的;海带粗加工产品不适于用做刺参饲料的主要成分.     

Mineral Requirements of Penaeus vannamei: A Preliminary Examination of the Dietary Essentiality for Thirteen Minerals

Diets containing a complete mineral premix or mineral premixes from which Ca, P, Na, CI, K, Mg, Mn, Fe, Zn, Cu, I, Se, or Cr were individually deleted were fed to juvenile Penaeus vunnamei (mean initial weight 79.5 mg) over a 4-week experimental period. Final mean percent weight gain ranged from 1,472 (Cu-free mineral premix) to 1,991% (Na-free mineral premix) with an average of 1,812% for all treatments. Survival during the first two week period and the second two week period was greater than 92% and 88%, respectively. There were no significant differences observed among treatments for growth and survival data.
Upon termination of the growth trial, the hepatopancreas and carapace were dissected from the shrimp and evaluated for ash, Ca, P, Na, K, Mg, Mn, Fe, Zn and Cu content. Of the minerals analyzed, the individual deletion of Mg, Mn, Fe, Zn and Cu from the mineral supplement resulted in reduced tissue mineralization in P. vannamei whereas, the deletion of Ca and P from the mineral mix did not produce significant responses. Deletion of Se from the mineral premix resulted in a significant increase in the ash content of the carapace. Based on the information provided by this and other studies, further investigation of the dietary requirements of P. vannamei for Ca, P, Fe, Mg, Mn, Zn, Cu and Se is recommended.     

海带配子体碳酸酐酶(CA)基因的克隆及其特征分析

根据海带雄配子体抑制消减cDNA文库2个长为376 bp的表达序列标签(expressed sequence tag,EST),Blastn搜索发现它们与掌状海带的碳酸酐酶(carbonic anhydrase,CA)基因序列(GenBank登录号:AJ130777)有70%的相似性,结合该EST以及掌状海带CA基因保守序列设计引物,扩增得到海带配子体CA基因部分开放阅读框(open reading frame,ORF)序列,再以此为基础设计基因特异性引物,然后利用cDNA末端快速扩增技术(rapid amplification of cDNA ends,RACE),克隆得到一条长2 804 bp的cDNA序列(GenBank登录号:JF827608),其中5′-非翻译区(untranslated region,UTR)长166 bp,3′-UTR长1 765 bp,且具有明显的polyA尾巴,ORF长873 bp。它编码一个由290个氨基酸组成的前体蛋白,预测在20 Gly-21 Val处有一个典型的信号肽酶切位点,酶切后的成熟蛋白由270个氨基酸组成,具有3个锌结合的His残基所构成的催化活性中心,其分子量为30.44 ku,等电点为5.06。无论在cDNA或者DNA序列上,雌、雄配子体CA基因都没有差异,且无内含子。Southern-blotting杂交结果显示,海带配子体CA基因为单拷贝基因。蛋白同源性搜索,发现该基因的编码蛋白与掌状海带的α-CA蛋白有87%的同源性。基于36个CA蛋白的氨基酸序列所构建的邻接(Neighbor-Joining)系统进化树显示,自海带配子体中所克隆的CA基因位于α-CA蛋白所组成的一支,推测它可能为α-型,因而不在线粒体中起作用。实时荧光定量PCR(quantitative real-time PCR,Q-RT-PCR)结果表明,在增加CO₂浓度的条件下,CA基因在海带雌、雄配子体中的日表达量均较未增加的条件下有所增加,由此推测该CA基因不属于胞外CA;基于海带配子体CA蛋白仅具有一个信号肽,可以推测它是定位于叶绿体外膜上,以泵的方式为叶绿体光合作用提供充足的CO₂。     

海带对131I吸收的研究

本文介绍了海带对^131I的吸收试验。试验结果表明：海带叶片在光照条件下，24小时内，对^131I的吸收量要比黑暗条件下高33％左右，这似乎说明海带对^131I的吸收与光合作用有关。海带不同部位的藻块对^131T的吸收能力，以梢部为最大，中部次之，基部最小。不同浓度的Pb、Cu和尿素对海带吸收^131I的能力有影响。     

海带加工现状研究

海带是一种含有碘、甘露糖、褐藻酸钠、多糖、膳食纤维、微量元素等高蛋白低脂肪的营养食材。本文对国内外海带加工现状和海带渣的研究进展进行简述,对未来海带加工进行展望,为促进海带产业发展提供新思路。     

Effect of two medicinal herbs (Astragalus radix and Lonicera japonica) on the growth performance and body composition of juvenile pikeperch [Sander lucioperca (L.)]

The aim of this study was to determine the impact of feeding juvenile pikeperch diets with medicinal herb adjuvants on the growth performance, proximate body composition, fatty acids profile (whole fish, muscle tissues, viscera) and cytological and histological indicators of the liver and middle intestine. The fish (mean body weight of ca. 110 g) were fed diets with a 0.1% supplement of Astragalus radix (group A), Lonicera japonica (group L) or a mixture of these herbs ( A. radix + L. japonica ; group A/L) for 8 weeks. The herbal supplementation was not noted to have had an impact on the analysed indicators of fish growth performance, condition or feed conversion ratio ( P >0.05). Statistically significant intergroup differences were noted in the value of the hepatosomatic index, hepatocyte size, their nucleus and nucleus/cytoplasm diameter ratio ( P <0.05). Significant intergroup differences were also noted in the appearance of the hepatic parenchyma. Statistically significant intergroup differences were also noted in the protein content of the whole fish body. The analysis of the proximal composition of the fish viscera, in turn, indicated significant differences in the fat content ( P <0.05). Among the analysed group of fatty acids (saturated – SFA, monoenoic – MUFA, polyenoic – PUFA) contained in the whole fish, the fillets and the viscera, significant intergroup differences were noted with regard to SFA (viscera) and MUFA (whole fish) ( P <0.05). The total PUFA content was stable, although significant intergroup differences were noted with regard to a few of the acids that belong to this group ( P <0.05).     

国内外海带加工现状与福建省的发展对策

本文对当今国内外海带资源以及加工利用状况进行了概述,简要介绍了国内外新型海带深加工产品,并提出了促进福建省海带产业健康发展的新思路.     

褐藻酸降解菌感染下海带活性氧产生的研究

以海带为材料，选用5株感染能力较强的褐藻酸降解菌作为致病菌，研究了活性氧（ROS）在海带抗褐藻酸降解菌感染中的产生及其作用。结果表明：（1）海带在褐藻酸降解菌感染下活性氧的产生具有普遍性。（2）活性氧的大量产生只发生在褐藻酸降解菌感染的早期阶段，随着感染时间的不断延长，活性氧的产生速率逐渐降低。说明活性氧的产生是海带在褐藻酸降解感染早期启动的反应特征之一。