湖南省小型甲壳动物新种和新记录

本文记述了湖南省首次记录的63种小型甲壳动物。其中包括一新亚种密纹尖额溞Alona verrucosa lineolata和6个中国新记录种和亚种.将国内学者以前记载的钩足平直溞Pleuroxus hamulatus移入锐额溞属,即钩足锐额溞Alonella hamulatus。

粗疣类钱袋苔[Apomarsupellaverrucosa(Nichols.)Vana]及其新异名

对产自中国云南缺萼苔科(Gymnomitriaceae)粗疣类钱袋苔(Apomarsupella verrucosa(Nichols.)Vana)和产自尼泊尔(Gymnomitrion papillosumKitag.&S.Hatt.)的模式标本进行了对比研究,发现Gymnomitrion papillosum和粗疣类钱袋苔特征相一致,将其处理为粗疣类钱袋苔的异名。

Transforming kelp into a marine bioreactor

The past decade has seen the genetic engineering of various types of seaweed. To date, genetic transformation studies have been carried out in several seaweeds, including the red seaweeds Porphyra, Gracilaria, Grateloupia, Kappaphyclus and Ceramium and the green seaweed Ulva. A genetic transformation model system has been established in the most commonly cultivated seaweed, the brown seaweed Laminaria japonica (kelp), based on the transfer of technology used in land plant transformation and also by modulating the seaweed life cycle. This model showed the potential for application of transgenic kelp to the production of valuable products and an indoor cultivation system for transgenic kelp was proposed, taking into account necessary factors for bio-safety. In this review, the establishment at use of the kelp transformation model is introduced, highlighting the potential for transforming kelp into a marine bioreactor.

Solving the coastal eutrophication problem by large scale seaweed cultivation

Eutrophication is becoming a serious problem in coastal waters in many parts of the world. It induces the phytoplankton blooms including 'Red Tides', followed by heavy economic losses to extensive aquaculture area. Some cultivated seaweeds have very high productivity and could absorb large quantities of N, P, CO2, produce large amount of O-2 and have excellent effect on decreasing eutrophication. The author believes that seaweed cultivation in large scale should be a good solution to the eutrophication problem in coastal waters. To put this idea into practice, four conditions should be fulfilled: (a) Large-scale cultivation could be conducted within the region experiencing eutrophication. (b) Fundamental scientific and technological problems for cultivation should have been solved. (c) Cultivation should not impose any harmful ecological effects. (d) Cultivation must be economically feasible and profitable. In northern China, large-scale cultivation of Laminaria japonica Aresch. has been encouraged for years to balance the negative effects from scallop cultivation. Preliminary research in recent years has shown that Gracilaria lemaneiformis (Bory) Daws. and Porphyra haitanensis Chang et Zheng are the two best candidates for this purpose along the Chinese southeast to southern coast from Fujian to Guangdong, Guangxi and Hong Kong. Gracilaria tenuistipitata var. liui Chang et Xia is promising for use in pond culture condition with shrimps and fish.

Molecular biotechnology of marine algae in China

Molecular biotechnology of marine algae is referred to as the biotechnology on the identification, modification, production and utilization of marine algal molecules. It involves not only the manipulation of macromolecules such as DNA, RNA and proteins, but also deals with low molecular weight compounds such as secondary metabolites. In the last decade, molecular systematic researches to investigate the relationship and to examine the evolutionary divergence among Chinese marine algae have been carried out by Chinese scientists. For example, RAPD has been widely used in several laboratories to elucidate genetic variations of the reds, such as Porphyra, Gracilaria, Grateloupia and the greens such as Ulva and Enteromorpha. Some important data have been obtained. The study on molecular genetic markers for strain improvement is now in progress. In 1990s, genetic engineering of economic seaweeds such as Laminaria, Undaria, Porphyra, Gracilaria and Grateloupia has been studied in China. For Laminaria japonica, the successfully cultivated kelp in China, a model transformation system has been set up based on the application of plant genetic techniques and knowledge of the algal life history. Progress has been made recently in incorporating a vaccine gene into kelp genome. Evidence has been provided showing the expression of gene products as detectable vaccines. In the present paper, the progress of molecular biotechnological studies of marine algae in China, especially researches on elucidating and manipulating nucleic acids of marine algae, are reviewed.

Algal biotechnology industries and research activities in China

In old China there were very few people engaged in the study of the algae, but in new China, freshwater and marine algae are studied by over one hundred old and new phycologists. There is now an algal biotechnology industry consisting of an aquaculture industry, producing large amounts of the seaweeds Laminaria, Porphyra, Undaria, Gracilaria, eucheumoids, and the microalgae Dunaliella and Spirulina. There is also a phycocolloid industry, producing algin, agar and carrageenan; an industry producing chemicals and drugs, such as iodine, mannitol, phycocyanin, beta -carotene, PSS (propylene glycol alginate sulfate) and FPS (fucose-containing sulfated polysaccharides) and an industry producing food, feed and fertilizer. The Laminaria cultivation industry produces about 900,000 t dry Laminaria, probably the largest producer in the world and 13,000 t algin, undoubtedly one of the largest algin producer in the world.

Dynamic changes of total bacteria and Vibrio in an integrated seaweed-abalone culture system

Polyculture of seaweeds alongside fed animal aquaculture is an environmentally friendly means of avoiding eutrophication problem both in land-based and sea-based monoculture systems. Many aspects of such polyculture systems have been described, but little attention has been given to the impact of live seaweeds on the microbiological properties of the water that connects the algae and animals. In this investigation, the Pacific red alga Gracilaria textorii was cultured in a recirculated dual tank system (150 L) with the juvenile abalone Haliotis discus hannai. Dynamic changes of total bacteria (TB) and total Vibrio (TV) in the water of polyculture and monoculture systems were evaluated. Results revealed that (1) level of TB in the polyculture was constantly higher than in the monoculture over a 6.5-day period. While levels of TV in the polyculture was detected to be constantly lower than in the monoculture, (2) integration of G. textorii in the abalone culture changed the Vibrio compositions in the water as judged by the changes of bacteria colony types; (3) application of artificial diet led to dramatic increase of the levels in TB and TV in both systems at 12 h after application in the 24-h test and resulted in selective propagation of Vibrio in the water in the monoculture system; (4) polyculture of G. textorii with juvenile abalone in combination with feeding with live algal diet helped to maintain low levels of TV and the balance of the Vibrio composition; (5) living biomass of G. textorii was effective in preventing propagation of two purified Vibrio strains (V alginolaticus and V logei) in the water. These results provide a general basis of the dynamic changes of levels in TB and TV in a seaweed-abalone polyculture system with or without artificial diet in tanks. (c) 2005 Elsevier B.V All rights reserved.

龙须菜和文蛤混养互利机制的模拟研究

近年来，在“清洁生产”、“生态养殖”以及“生物修复”理论的指导下，在贝类稚贝培育和成贝养殖过程中实施贝藻混合模式，已经成为国内外学者研究的热点之一。本文在封闭水体中进行了龙须菜（Gracilaria lemaneiformis Weber-van Bosse）和文蛤（Meretrix meretrix Linnaeus）稚贝以及成贝的混养实验，初步探索了混养系统中的互利机制，监测了水体中理化因子和生物因子的变化规律，测定了养殖生物的生长情况及营养成分，构建了混养系统中贝藻混养的合理模式。并且采用新技术－T-RFLP监测了养殖水体中细菌的动态变化。主要研究成果如下： 1． 在龙须菜与稚贝混养实验中，平均水温为17.5±3.2℃。研究结果表明较低的温度抑制了龙须菜的生长，总平均日生长率最高为0.81％/d，小于与成贝混养实验的最高特定生长率1.79％/d。养殖水体中氨氮和磷酸盐是最主要的无机污染物，而龙须菜对养殖水体营养盐的去除作用显著， 35天后混养系统中养殖水体的氨氮和磷酸盐平均浓度较单养系统低43.37μmol/L、1.23μmol/L，分别相差95.06%、94.85％。 2． 在龙须菜与成贝混养实验中，平均水温为23.1±2.3℃，适合龙须菜的生长，结果表明龙须菜对氨氮和亚硝氮的吸收高达86％～98％，对无机磷的吸收可达99％，养殖生物的生长情况良好，养殖生物体内的营养成分要好于单养系统中的养殖生物。对于氨基酸总含量，加入龙须菜的养殖系统中文蛤体内的氨基酸总含量要比单养系统中文蛤体内氨基酸总含量高26.0mg/g，高出后者5.01％。引入龙须菜在一定程度上可以抑制异养细菌和致病性弧菌的生长，相对抑制率达到77.75％。在本实验中，尽管龙须菜可以抑制异养细菌的生长，但如果引入过多会导致嗜江蓠细菌过度增加，可能反而会破坏原有的微生态平衡。 3． 采用T-RFLP技术对养殖水体中的总细菌群落进行了分析，摸索出合理的方法和步骤，通过聚类分析将养殖水体中细菌群落分为两个群落，并且认为在养殖水体中，微生物群落的变化是及其复杂的，第六周时两个群落变化不一致。并且相对来说，龙须菜的引入可能会对某些群落造成抑制，但也可能会对其它细菌群落起到促进作用。 4． 稚贝和成贝分别与龙须菜的混养实验结果表明，在养殖系统中引入龙须菜可以改善养殖环境，龙须菜和文蛤的适宜混合比例为1：1能取得较好的生态效应。

海藻表面附着弧菌多样性分析及方法研究

对四种大型海藻：江篱(Gracilaria textorii)、孔石莼（Ulva pertusa）、海带苗（Laminaria japonica）和多管藻（Polysiphonia urceolata）表面附着弧菌的多样性进行了分析，同时对多样性分析中采用的不同方法进行了比较。 利用TCBS培养基从四种海藻表面总共分离到12株细菌：G1、G2分离自江篱，U3分离自孔石莼，L4、L5、L6分离自海带苗，P7、P8、P9、P10、P11、P12分离自多管藻。菌株G1，G2属于盐单胞菌(Halomonas)，其余10株细菌都属于弧菌(Vibrio)。 对12株细菌的酶学活性、抗生素抗性进行了研究。发现除G1、G2外，其余菌株都可产生淀粉酶和明胶酶。菌株G1、G2和U3对氨苄青霉素、链霉素和四环素有很强抗性。 采用多种分子生物学方法（16S rDNA、gyrB、RFLP、DGGE ）分析了上述12株菌的系统发育关系，对不同方法获得的结果进行了比较。 12株菌的16S rDNA系统发生树可分为4个明显分支。G1、G2与细菌H. meridiana构成一个分支。U3与V. lentus构成一个分支。L4、L5、L6、P9、P10、P11、P12与V. tasmaniesis形成一个分支。P7、P8与V. splendidus形成一个分支。 以gyrB基因序列为基础构建的系统发生树将G1、G2以外的10株弧菌分成4个较大分支，L4、P9属于同一分支，L6、P8、P10、P11和P12属于一个大的分支， U3、L5各自构成一个分支。菌株G1、G2没有得到gyrB基因序列扩增带。表明试验设计的引物是弧菌特异性引物。相对16S rDNA，不同菌株间gyrB基因序列差异性更大。 RFLP分析结果显示，12株细菌HinfI酶切后得到6种带型，SmaI酶切后得到4种带型。结合16S rDNA、gyrB基因的分析结果可知，RFLP可以在种的水平上有效进行细菌多样性分析。 12株细菌的DGGE分析结果显示，G1、G2与其它菌株电泳图谱有明显不同。菌株U3独自构成一种带型，L5、L6构成一种带型。表明DGGE技术在属的水平上分析细菌多样性效果较好，在种的水平上分析细菌多样性有一定的局限性。

红藻无性繁殖系的诱导及其发育机制的初步研

以红藻中的角叉菜（Chondrus ocellatus）、龙须菜（Gracilaria lemaneiformis）、真江蓠(Gracilaria asiatica)和海膜（Halymenia sinensis）为材料，观察了红藻幼苗的早期发育，通过组织培养构建无性繁殖系，并初步探讨了红藻无性繁殖系的发育及分化机理，为海藻无性繁殖系的获得提供理论基础和依据。 在室内进行了角叉菜的四分孢子和果孢子的细胞培养，并观察其早期发育过程。结果表明，四分孢子和果孢子的早期发育是相似的，可主要分为三个阶段：早期分裂阶段、盘状体阶段和直立体形成阶段。 切段组织培养表明，红藻无性繁殖系的获得主要通过两种途径：一种为切段组织经过培养可直接形成再生植株；另一种为切段组织经培养脱分化，诱导出愈伤组织或类愈伤组织，愈伤组织或类愈伤组织再分化，形成盘状体，盘状体继续发育即可形成再生植株。 通过切段组织培养，获得了龙须菜和真江蓠再生植株。在PES培养液中，添加6－BA（0.25 mg/L）对龙须菜切段组织再生新枝的诱导有促进作用，诱导率可高达84.4％，高浓度的IAA或6－BA（4 mg/L）对切段组织有损伤作用。实验证明伤口大小对切段组织再生新枝有影响，且伤口太大对再生新枝的形成不利。龙须菜的切段组织培养过程中表现出极性。 通过组织培养，诱导出海膜类愈伤组织—丝状体。添加植物生长调节类物质（IAA 和 6-BA）对海膜丝状体的诱导无促进作用。海膜切片在消毒海水中培养即可获得丝状体。海膜丝状体的外植体来源主要有两个：一是健康的藻体； 另一是盘状体，其丝状体的诱导率分别为80％ 和90％。筛选出了丝状体适宜的生长条件：13－23℃，10－15 μE•m−2• s−1，12h：12h（Light: Dark），其中18℃为最佳生长温度。高的光照强度（50 μE•m−2•s−1）对丝状体产生损伤作用。 红藻无性繁殖系的发育途径，根据其获得途径也有两种情况。经过切段组织培养直接获得的无性繁殖系，是切段切口处已分化的细胞表现其全能性，恢复分裂能力，再生新枝，切段表现出极性。极性的上端产生新枝，下端形成固着器，成为一个完整的植株。经过愈伤组织和类愈伤组织获得的无性繁殖系，是切口处已分化的细胞表现其全能性，经脱分化形成愈伤组织和类愈伤组织，附着在基质上后，再分化形成盘状体，按照孢子的早期发育途径，形成直立体幼苗。 通过SDS-聚丙烯酰胺凝胶电泳分析，对龙须菜正常藻体及无性繁殖系发育过程中蛋白的表达进行检测，检测出表达差异的蛋白质，推测这两个蛋白可能与龙须菜切段组织再生有关，其中30 KD的蛋白仅在再生新枝中表达，150 KD和125 KD的蛋白仅在正常生长的龙须菜和龙须菜切段的极性下端中表达。 根据高等植物中与萌芽、分生组织以及愈伤组织发育相关的基因序列保守区设计了五对特异引物，通过PCR和RT-PCR扩增检测及DNA测序分析，对红藻无性繁殖系早期发育相关的基因序列，进行了初步分析。

Isolation and identification of bacteria associated with the surfaces of several algal species

We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses. Twelve strains of bacteria were obtained from the surfaces of the following four species of algae: Gracilaria textorii, Ulva pertusa, Laminaria japonica, and Polysiphonia urceolata. The isolated strains of bacteria can be divided into two groups: Halomonas and Vibrio, in physiology, biochemical characteristics and 16S rDNA sequence analyses. The phylogenetic tree constructed based on 16S rDNA sequences of the isolates shows four obvious clusters, Halomonas venusta, Vibrio tasmaniensis, Vibrio lentus, and Vibrio splendidus. Isolates from the surface of P. urceolata are more abundant and diverse, of which strains P9 and P28 have a 16S rDNA sequence very similar (97.5%-99.8%) to that of V. splendidus. On the contrary, the isolates from the surfaces of G textorii, U. pertusa and L. japonica are quite simple and distribute on different branches of the phylogenetic tree. In overall, the results of this study indicate that the genetic relationships among the isolates are quite close and display a certain level of host species specificity, and alga-associated bacteria species are algal species specific.

Determination of chemical species of iodine in some seaweeds .1.

The chemical species of iodine in seven marine algae Codium fragile, Ulva pertusa, Monostroma nitidum, Gracilaria confervoides, Sargassum Kjellmanianum, Dictyopteris divaricata and Laminaria japonica were studied using neutron activation analysis combined with chemical separation. The contents of total iodine, water-soluble iodine, soluble organic iodine, I- and IO3- were determined. The results indicate that the chemical species and contents of iodine in various algae are remarkably different. The highest iodine content of 734 mg/kg (wet basis) was found in Laminaria japonica, with 99.2% of the total iodine being water soluble. The iodine contents of the other six algae are lower and soluble iodine makes up 16-41% of the total. In the aqueous leachate, iodine is mainly I-, which amounts to 61-93% of total water-soluble iodine; the percentages of organic iodine making up 5.5-37.4%, while the contents of IO3- are the lowest, 1.4-4.5%. This result suggests that the mechanism of iodine enrichment is different for various algae and that its bioavailability varies as well. (C) 1997 Elsevier Science B.V.