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提江沿海浒苔属（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,依据藻体分校的有元、数量及分校与主枝直径的大小等形态特征,鉴定的浒苔属j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. proliferα）、 条浒苔（E. clathratα）、由浒苔（ E·flexω5α）和肠浒苔宽叶变型（ E. intestinalis f.broadifolium） 0藻体长度由 大到小依次为浒苔、条浒苔、缘管浒苔、肠浒苔、扁浒苔和炀浒苔宽叶变型：细胞呈多角形,藻体的位置不同其细胞大小有所变化,除由浒苔和条浒苔外,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、缘管浒苔和扇浒苔仅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营状的结构特征。     

海南省三亚海藻资源调查

通过对海南島三亚海藻的分布和种类进行深入调查,采集和整理了标本123号,计35属53种,并分析了三亚的气候和环境条件对海藻的生长与分布的关系,为三亚海藻的开发与利用提供了第一手资料。     

DYNAMIC STUDIES ON FLAGELLAR REGENERATION IN DUNALIELLA SALINA

INTRODUCTIONMicroalgalbiotechnologyhasattractedmoreandmoretheinterestofscientistsandpeopleex ploitingitscommercialpossibilitiesasitisthebiotechnologythatcanmatchbacterialbiotechnologyinthecomingcenturyintheaspectofeconomicreturnoninvestment.Dunaliellasalinaisoneofthemostdetailedlystudiedunicellulargreenalgae,hassomeuniquescientificvalues,andgreatestpotentialformasscultureasafoodsource ,andisrichestalgalsourceofglycerolandβ carotene(Borowitaka,1 988;Ginzburg,1 987) .Optimizingperformanceo…     

Lytic Characteristics and Identification of Two Alga-lysing Bacterial Strains

Lytic Characteristics and Identification of Two Alga-lysing Bacterial StrainsBeaulieu, S. E., M. R. Sengco, and D. M. Anderson, 2005. Using clay to control harmful algal blooms: deposition and resuspension of clay/algal flocs. Harmful Algae . (4): 123-138…     

The Mechanism of Lipids Extraction from Wet Microalgae Scenedesmus sp. by Ionic Liquid Assisted Subcritical Water

In this paper, the total sugar concentration, protein concentration, lipid yield and morphology characteristics of the algae residue were determined to explain the mechanism of lipids extraction from wet microalgae Scenedesmus sp. by ionic liquid assisted subcritical water. The results showed similar variation for the sugar, protein and lipid. However, the total sugar was more similar to lipids yield, so the results showed that the reaction between ionic liquid and cellulose and hemicellulose in cell wall was the most important step which determined the lipids extration directly. And the total sugar variation may be representing the lipids yield. For later lipids extraction, we can determine the total sugar concentration to predict the extraction end product.     

Abundance, biomass and composition of spring ice algal and phytoplankton communities of the Laptev Sea （Arctic）

Abundance,biomass and composition of the ice algal and phytoplank-ton communities were investigated in the southeastern Laptev Sea in spring 1999.Diatoms dominated the algal communities and pennate diatoms dominated the dia-tom population.12 dominant algal species occurred within sea ice and underlyingwater column,including Fragilariopsis oceanica,F.cylindrus,Nitzschiafrigida,N.promare,Achnanthes taeniata,Nitzschia neofrigida,Naviculapelagica,N.vanhoef fenii,N.septentrionalis,Melosira arctica,Clindrothecaclosterium and Pyrarnimonas sp.The algal abundance of bottom 10 cm sea icevaried between 14.6 and 1562.2×10~4 ceils l~(-1)with an average of 639.0×10~4cells l~(-1),and the algal biomass ranged from 7.89 to 2093.5μg C l~(-1)with an av-erage of 886.9μg C l~(-1),which were generally one order of magnitude higherthan those of sub-bottom ice and two orders of magnitude higher than those ofunderlying surface water.The integrated algal abundance and biomass of lower-most 20 cm ice column were averagely 7.7 and 12.2 times as those of upper 20 mwater column,respectively,suggesting that the ice algae might play an importantrole in maintaining the coastal marine ecosystem before the thawing of sea ice.Icealgae influenced the phytoplankton community of the underlying water column.However,the“seeding”of ice algae for phytoplankton bloom was negligible be-cause of the iow phytoplankton biomass within the underlying water column.     

Dynamic studies on flagellar regeneration inDunaliella salina

Flagella, the basic locomotive organ in algae, as well as bacteria and some cells of animals or high plants, would be damaged in the well stirred mass culture due to the strong forces caused by the fast mixing impellers. The dynamic regeneration of the flagella in deflagellatedDunaliella salina was studied microscopically by using a bench-top flat-bottom photobioreactor. The results showed that 90 minutes was necessary for the repair of flagella, after which half of the cells became motile as their flagella generated within 120 minutes and nearly all of the cells could swim freely within 180 minutes. Contribution No. 3503 from the Institute of Oceanology, Chinese Academy of Sciences.     

Fabrication of anodized superhydrophobic 5083 aluminum alloy surface for marine anti-corrosion and anti-biofouling

Marine corrosion and biofouling seriously affect the service life of marine structural materials,resulting in performance failure,enormous economic loss,and even catastrophic safety accidents.It is worthwhile and desirable to develop high-efficiency strategy for anti-corrosion and anti-biofouling.In this paper,superhydrophobic 5083 aluminum alloy(AA5083) surface with micro-nano hierarchical morphology was fabricated through anodization followed by 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane(POTS)modification.The surface morphologies,roughness,and chemical compositions were revealed by scanning electron microscopy,atomic force microscopy,and X-ray diffraction.The self-cleaning ability,corrosion resistance and algae adhesion suppression ability of the fabricated surfaces were investigated,indicating an excellent water-proofing,anti-corrosion and anti-biofouling performance.We believe the superhydrophobic creation of metallic materials is expected to have potential applications in marine corrosion and antibiofouling fields.     

Automatic cell object extraction of red tide algae in microscopic images

Extracting the cell objects of red tide algae is the most important step in the construction of an automatic microscopic image recognition system for harmful algal blooms.This paper describes a set of composite methods for the automatic segmentation of cells of red tide algae from microscopic images.Depending on the existence of setae,we classify the common marine red tide algae into non-setae algae species and Chaetoceros,and design segmentation strategies for these two categories according to their morphological characteristics.In view of the varied forms and fuzzy edges of non-setae algae,we propose a new multi-scale detection algorithm for algal cell regions based on border-correlation,and further combine this with morphological operations and an improved GrabCut algorithm to segment single-cell and multicell objects.In this process,similarity detection is introduced to eliminate the pseudo cellular regions.For Chaetoceros,owing to the weak grayscale information of their setae and the low contrast between the setae and background,we propose a cell extraction method based on a gray surface orientation angle model.This method constructs a gray surface vector model,and executes the gray mapping of the orientation angles.The obtained gray values are then reconstructed and linearly stretched.Finally,appropriate morphological processing is conducted to preserve the orientation information and tiny features of the setae.Experimental results demonstrate that the proposed methods can effectively remove noise and accurately extract both categories of algae cell objects possessing a complete shape,regular contour,and clear edge.Compared with other advanced segmentation techniques,our methods are more robust when considering images with different appearances and achieve more satisfactory segmentation effects.     

细基江篱繁枝变种在不同水层中的栽培试验

本文报道了为改变我国华南沿海目前在半咸淡水塘中进行地播式裁培细基江篱繁枝变种单产低的状况而进行的不同水层夹苗栽培和施肥增产试验,证明了越靠近水面江篱藻体生长越快,越接近底部藻钵生长越差,提出如果在水塘中单纯裁培江篱则水塘深度应保持20～30厘米,如果水深超过1米以上,则应采用浮筏式夹苗栽培,并在水中混养鱼虾等。浸泡施肥试验证明,在短短的40天裁培过程施肥藻体比不施肥藻体增产23％,说明了施肥的重要性。     

Dynamic Diurnal Changes in Green Algae Biomass in the Southern Yellow Sea Based on GOCI Images

Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007, inducing severe ecological problems and huge economic losses. Genesis and secular movement of green algae blooms have been well monitored by using remote sensing and other methods. In this study, green algae were detected and traced by using Geostationary Ocean Color Imager(GOCI), and a novel biomass estimation model was developed from the relationship between biomass measurements and previously published satellite-derived biomass indexes. The results show that the green algae biomass can be determined most accurately with the biomass index of green algae for GOCI(BIGAG), which is calculated from the Rsurf data that had been atmospherically corrected by ENVI/QUAC method. For the first time, dynamic changes in green algae biomass were studied over an hourly scale. Short-term biomass changes were highly influenced by Photosynthetically Available Radiation(PAR) and tidal phases, but less by sea surface temperature variations on a daily timescale. A new parameter of biomass changes(PBC), calculated by the ratio of the biomass growth rate to movement velocity, could provide an effective way to assess and forecast green tide in the southern Yellow Sea and similar areas.     

太湖蓝藻水华遥感动态监测预警模型的建立

湖泊富营养化和蓝藻水华暴发是当前我国湖泊面临的最重要的环境问题之一。本文分析了内陆湖泊太湖蓝藻监测的主要问题。并详细阐述了蓝藻水华遥感动态监测预警模型的建立,即,采用生物光学模型与气象环境预警模型相结合的方式,辅以图形图像学的模块匹配验证,对蓝藻水华暴发前进行临界状态的灾害等级警示,理论上较单纯监测微囊藻叶绿素a浓度值来实现水华暴发预警更为准确。这样,提前采取相应的技术措施,减少蓝藻水华暴发带来的影响和损失。     

Composition and Origin of Ferromanganese Crusts from Equatorial Western Pacific Seamounts

In the equatorial western Pacific, iron-manganese oxyhydroxide crusts(Fe-Mn crusts) and nodules form on basaltic seamounts and on the top of drowned carbonate platform guyots that have been swept free of pelagic sediments. To date, the Fe-Mn crusts have been considered to be almost exclusively of abiotic origin. However, it has recently been suggested that these crusts may be a result of biomineralization. Although the Fe-Mn crust textures in the equatorial western Pacific are similar to those constructed by bacteria and algae, and biomarkers also document the existence of bacteria and algae dispersed within the Fe-Mn crusts, the precipitation, accumulation and distribution of elements, such as Fe, Mn, Ni and Co in Fe-Mn crusts are not controlled by microbial activity. Bacteria and algae are only physically incorporated into the crusts when dead plankton settle on the ocean floor and are trapped on the crust surface. Geochemical evidence suggests a hydrogenous origin of Fe-Mn crusts in the equatorial western Pacific, thus verifying a process for Fe-Mn crusts that involves the precipitation of colloidal phases from seawater followed by extensive scavenging of dissolved trace metals into the mineral phase during crust formation.     

Negative effects of Phaeocystis globosa on microalgae

The potential allelopathic effects of the microalga, Phaeocystis globosa Scherffel, on three harmful bloom algae, Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Chattonella ovata Hara et Chihara were studied. The growth of C. marina and C. ovata was markedly reduced when the organisms were co-cultured with P. globosa or cultured in cell-free spent medium. Haemolytic extracts from P. globosa cells in the senescence phase had a similar inhibitory effect on the three harmful bloom algae. However, P. globosa had less influence on the brine shrimp, Artemia salina. These results indicate that P. globosa may have an allelopathic effect on microalgae, which would explain the superior competitive abilities of P. globosa. Because the addition of the haemolytic toxins from P. globosa had similar effects on algae as spent media, these compounds may be involved in the allelopathic action of P. globosa.     

Biofilm formation under high temperature causes the commensal bacteria Bacillus cereus WPySW2 to shift from friend to foe in Neoporphyra haitanensis in vitro model

Although biofilm formation may promote growth, biofilms are not always beneficial to their hosts. The biofilm formation characteristics of Bacillus cereus WPySW2 and its changes at different temperatures were studied. Results show that B. cereus WPySW2 promoted the growth of Neoporphyra haitanensis (an economically cultivated seaweed) at 20 °C but accelerated algal rot at 28 °C. Thicker B. cereus WPySW2 biofilms covered the surface of N. haitanensis thalli at 28 °C, which hindered material exchange between the algae and surrounding environment, inhibited algal photosynthesis and respiration, and accelerated algal decay. Compared with planktonic bacteria, mature biofilm cells had lower energy consumption and metabolic levels. The biofilm metabolic characteristics of B. cereus WPySW2 changed significantly with temperature. High temperature accelerated biofilm maturation, which made it thicker and more stable, allowing the bacteria to easily adapt to environmental changes and obtain greater benefits from their host. High temperature did not affect the production or increased the abundance of toxic metabolites, indicating that the negative effects of B. cereus WPySW2 on algae were not caused by toxins. This study shows that increased temperature can transform a harmless bacterium into a detrimental one, demonstrating that temperature may change the ecological function of phycospheric bacteria by affecting their morphology and metabolism.

     

A review of heavy metal adsorption by marine algae

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ASPECTS OF IRON NUTRITION IN MACROALGAE ULVA PERTUSA (CHLOROPHYTA) UNDER IRON STRESS

ＩＮＴＲＯＤＵＣＴＩＯＮＩｒｏｎｉｓａｎｉｍｐｏｒｔａｎｔｎｕｔｒｉｔｉｏｎａｌｅｌｅｍｅｎｔｉｎａｌｇａｅｊｕｓｔａｓｉｔｉｓｉｎｈｉｇｈｐｌａｎｔｍｅｔａｂｏｌｉｃｐａｔｈｗａｙｓ.Ｐｈｏｔｏｓｙｎｔｈｅｓｉｓｉｓｄｅｐｅｎｄｅｎｔｏｎｔｈｉｓｅｌｅｍｅｎｔｂｅｃａｕｓｅｃｈｌｏｒｏｐｈｙｌｌｓｙｎｔｈｅｓｉｓｒｅｑｕｉｒｅｓｉｒｏｎｎｕｔｒｉｔｉｏｎ .Ｉｒｏｎｉｓａｌｓｏｅｓｓｅｎｔｉａｌｆｏｒｃｙｔｏｃｈｒｏｍｅｓ,ｆｅｒｒｅｄｏｘｉｎ ,ａｎｄＦｅ ｓｐｒｏｔｅｉｎ .Ｉｔｓｂｉｏｃｈｅｍｉ…     

Bromophenols from marine algae with potential anti-diabetic activities

Marine algae contain various bromophenols with a variety of biological activities,including antimicrobial,anticancer,and anti-diabetic effects.Here,we briefly review the recent progress in researches on the biomaterials from marine algae,emphasizing the relationship between the structure and the potential anti-diabetic applications.Bromophenols from marine algae display their hyperglycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B,α-glucosidase,as well as other mechanisms.     

盐度对威氏海链藻生长和生化指标的影响

【目的】研究威氏海链藻在不同盐度条件下的生长和生化组分变化。【方法】设置盐度梯度为5、15、25、35、45,采用血细胞计数板计数法、热乙醇提取法、尼罗红染色法、苯酚硫酸法和考马斯亮蓝法,分别测定威氏海链藻在不同盐度下的生物量、叶绿素a、类胡萝卜素、中性脂质、总糖和蛋白质含量。【结果】盐度对威氏海链藻细胞密度影响显著(P<0.05),当盐度25和盐度35时,培养8 d细胞密度最高,均为2.0×10⁶ mL^-1;盐度对威氏海链藻叶绿素a和类胡萝卜素含量有显著影响(P<0.05),当盐度15时,细胞叶绿素a和类胡萝卜素含量均最高,分别为3.4814μg/mL(4 d)、2.3549μg/mL(8 d)。盐度对威氏海链藻可溶性总糖含量有显著影响(P<0.05),当盐度15时,8 d时可溶性总糖积累含量最高,为123μg/mL。当盐度35时,6 d时可溶性蛋白积累含量最高,为142.9μg/mL,且显著高于其他实验组(P<0.05)。盐度45时,8 d时中性脂含量最高,显著高于其他实验组(P<0.05)。【结论】盐度为15~35时,威氏海链藻生长速度较快,生化组成较为稳定,盐度15时最有利于藻细胞叶绿素a和类胡萝卜素、总糖的合成;盐度25和盐度35时,藻细胞平均增长速度较快,盐度35时最有利于藻细胞可溶性蛋白积累。