Enteromorpha Linza Research Articles

EVALUATION OF NUTRITIONAL COMPOSITION OF SOME ATTACHED AND DRIFTED MARINE ALGAE FROM ALEXANDRIA, EGYPT

Chemical composition of eight Egyptian marine macroalgae, Ulva lactuca and Enteromorpha linza (Chlorophyceae); Dictyota dichotoma, Sargassum vulgare and Cystoseira spinosa (Phaeophyceae); Pterocladia capillacea, Corallina officinalis and Jania rubens (Rhodophyceae), was determined. Water content in all algae analyzed was high (

서해 경기만 해조군집 복원을 위한 기초생태조사

For getting primary cue of restoration, the algal flora and intertidal community structure of Deokjeokdo, Yeonpyeongdo and Ganghwado were investigated for from February to November 2006. The total of 28 species, including five Chlorophytes, five Phaeophytes, 17 Rhodophytes and one sea grass were identified. The occurrence of species according to sampling site was 22 species in Deokjeokdo, seven species in Yeonpyeongdo and four species in Ganghwado. Among them Gloiopeltis furcata, Ulva pertusa and Sargassum horneri in Deokjeokdo, Scytosiphon lomentaria in Yeonpyeongdo, Enteromorpha prolifera in Ganghwado were ominants. The algal zonation of intertidal zone was figured out by Gloiopeltis furcata, Caulacanthus okamurae – Corallina pilulifera – Ulva pertusa, Ahnfeltiopsis flabelliformis, Sargassum horneri, Undaria pinnatifida in Deokjeokdo, Bangia atropurpurea – Scytosiphon lomentaria – Ahnfeltiopsis flablleiformis in Yeonpyeongdo from upper to lower zone and Enteromorpha prolifera, Enteromorpha linza – Sargassum thunbergii, Myelophycus simplex in Ganghwado from middle to lower zone. The average of biomass was measured as 80.6 g dry wt. m–2 in Deokjeokdo, 32.2 g dry wt. m–2 in Yeonpyeongdo and less than 1 g dry wt. m–2 in Ganghwado.

해조류 추출물로부터의 Photosensitizing 효과를 지니는 항 적조물질 탐색

Photosensitized extracts of 28 seaweed species were tested in vitro to examine the variation in their algicidal activities against the toxic microalga Cochlodinium polykrikoides. When both seaweed extracts and microalgae were exposed to UV and visible light, methanol extracts of Porphyra yezoensis showed 5.7- and 4.4-fold increasesin light-dependent algicidal activity, respectively. When only seaweed extracts were exposed to both UV (365 nm) and visible light (white lamp) at the same time, methanol extracts of Enteromorpha linza and Carpopeltis affinis showed 3.3- and 3.4-fold increases in algicidal activity, respectively. When UV-photosensitized extracts were left in the dark, the algicidal activity of Ecklonia cava increased 13-fold after 5 h. When visible light-photosensitized extracts were left in the dark, the algicidal activity of Monostroma nitidum increased by 3.3-fold in 1 h.

Fatty acid composition of marine macroalgae from the Black Sea and Dardanelles

The fatty acid (FA) composition was determined in 14 species of marine macroalgae belonging to the Chlorophyta, Phaeophyta and Rhodophyta, which were collected from Şile in the Black Sea and Kepez in the Dardanelles. Generally, polyunsaturated FAs and monounsaturated FAs were major components (50–77%). Total saturated FAs ranged from 22% to 50%, with 16 : 0 as the most abundant saturate (32–38%). Two samples of Cystoseira barbata collected from a different station had some differences from each other in their contents of 18 : 2n-6 and 18 : 3n-3 and in the 18 : 2n-6/20 : 4n-6 ratios. Green algal species had a significantly higher proportion of unsaturated FAs and a significantly lower proportion of saturated FAs than the red and brown algae. The amount of n-3 FAs was significantly higher in Ulva rigita, Chaetomorpha linum, Enteromorpha linza and Gracilaria verrucosa (8.88, 6.44, 5.31 and 5.24, respectively).

Marine Macro-algae of Orissa, East Coast of India

A total of twenty one species of marine macro-algae were reported from 460 kms long Orissa coast in the east coast of India. Of these 9 species belongs to Chlorophyta, 2 to Phaeophyta and 10 to Rhodophyta. The low species richness compared with southern and western coasts of India was due to lack of rocky and/or coral substratum. Enteromorpha usneoides and Gelidium divaricatum were reported first from India. Enteromorpha linza, E. clathrata, Colpomenia sinuosa, Dictyota dichotoma, Catenella impudica, Compsopogon aeruginosus and Grateloupia lithophila were the new records for Orissa coast.

제주 자생 해양 녹조류와 갈조류 추출물로부터의 항고혈압 활성

제주 연안에 서식하는 해양 녹조류와 갈조류의 항고혈압 활성을 알아보기 위해 해조류로부터 메탄올과 물을 이용하여 상온(20℃)과 70℃에서 각각 4가지 종류의 추출물을 제조하여 스크리닝하였다. 그 결과, 녹조류에서는 비교적 낮은 ACE 저해활성을 보였으나, 갈조류에서는 70ME 잇바디괭생이모자반, 말미역, 바위주름, 넓패, 톳, 다시마 및 70AE 감태에서 ACE 저해활성이 높게 나타났다. 또한 70AE 감태의 가수분해물은 2.33～3.56 ㎍/mL의 IC<SUB>50</SUB>값을 보여 매우 높은 ACE 저해활성을 확인할 수 있었다. 이는 해조류의 ACE 저해활성이 수용성 추출물뿐만 아니라 메탄올 추출물에서도 나타나는 것은 해조류 유래 fucoxanthin, phlorotannin 및 polyphenol계 화합물 등에 의한 영향도 있을 것으로 사료된다.

Comparative study of heavy metal distribution in some coastal seaweeds of Alexandria, Egypt

The distribution of Cd, Cu, Fe, Hg, Mn, Ni, Pb, and Zn concentration in five algae species (Enteromorpha intestinalis, Enteromorpha linza, Ulva lactuca, Corallina mediterranea, Pterocladia capillacea) collected from three areas having different types of metal contamination along Alexandria coastal waters (Egypt) were determined by Atomic Absorption Spectrometry. The recovery study was carried out using a Certified Reference Material TORT-2. The obtained heavy metal contents indicate that different species demonstrate various degree of metal accumulation. Enteromorpha intestinalis (green algae) recorded the highest levels of Fe and Mn while Corallina mediterranea (Calcareous red algae) recorded the highest concentration of Pb, Ni, and Cd in the three areas under study. According to the present study, filamentous algae (Enteromorpha intestinalis) showed the ability to concentrate greater amount of trace elements than the foliaceous ones (Enteromorpha linza). In each area, mercury concentration has nearly the same value for all species under study.

The influence of surface energy on the wetting behaviour of the spore adhesive of the marine alga Ulva linza (synonym Enteromorpha linza )

The environmental scanning electron microscope has been used to image the adhesive pads secreted by zoospores of the marine alga Ulva linza as they settle on a range of self-assembled and grafted monolayers of different wettability, under natural, hydrated conditions. Results reveal that the diameter of the adhesive pad is strongly influenced by surface wettability, the adhesive spreading more (i.e. wetting the surface better) on the more hydrophilic surfaces. This is in direct contrast to previous observations on the spreading of marine bioadhesives and is in apparent contradiction to the predictions of the Young-Dupre equation for three-phase systems. In this paper, we attempt an explanation based upon thermodynamic analysis of the wetting properties of hydrophilic proteins.

Roughness-dependent Removal of Settled Spores of the Green Alga Ulva (syn. Enteromorpha) Exposed to Hydrodynamic Forces from a Water Jet

Topographic features change the hydrodynamic regime over surfaces subjected to flow. Hydrodynamic microenvironments around topographic structures may have consequences for recruitment and removal of propagules of marine benthic organisms. The settlement and adhesion of zoospores from the green alga Ulva linza (syn. Enteromorpha linza) to defined topographies was investigated. A range of topographic size scales (Rz: 25 – 100 μm) was manufactured from plankton nets, creating patterns with ridges and depressions. The topographic scales span a roughness similar to that of natural substrata and antifouling coatings. Spores were removed from the surfaces by a calibrated water jet. Fewer spores were removed from the smallest topographic structure tested (Rz: 25 μm) compared to both the smooth (Rz: 1) and the roughest (Rz: 100 μm) structures. Zoospores that settled in depressions were less likely to be removed compared to spores on the ridges. The results in terms of the interaction between surface topography and hydrodynamic forces have implications for both natural substrata exposed to wave action and antifouling surfaces on ships' hulls. The possible effects of topography on increasing zoospore adhesion and offering a refuge from hydrodynamic forces are discussed.

하계 독도 연안 해조류의 종조성 변동과 갯녹음현상

This study was to clarify the variations in a marine ecosystem through examining the species composition of benthic algae in the coast of Dokdo Island during summer (June & August, 2003). The total number of species found in benthic algae was 45 composed of 11% green algae, 29% red algae and 60% brown algae. The dominant species were Enteromorpha linza, Cladophora spp. and Codium frgile for green algae, Ecklonia cave, Eisenia bicyclis, Sargassum confusum, S. patens, S. horneri, Myagropsis myagroides for brown algae and Amphiroa cphedrace. A pusilla, Lithophyllum okamurae, Corallina spp. Laurencia pinnata, L. hamata, Chondria crassicaulit, C. dasyphylla, Gelidium amansii, Neosiphonia yendoi and Polysiphonia yendoi for red algae. The number of benthic algal species decreased more in this study than in previous researches. The whitening of the rocky shore might provoke the decrease of benthic algal biomass and species.ጊ缀Ѐ㘰〻Ԁ䭃䑎䴀

Macroalgal assemblage structure on a coral reef in Nanwan Bay in southern Taiwan

Four-season surveys of macroalgal assemblage structure on a coral reef in southern Taiwan were performed by transect investigation from October 1999 through August 2000. Species richness increased over time, and percentage cover and biomass peaked in April. Non-metric multidimensional scaling ordination analysis of species similarities between stations showed three distinct clusters corresponding to the upper reef flat, the lower reef flat and the reef slope. The macroalgal assemblage on the lower reef flat was further grouped into two clusters corresponding to the warmer months (October 1999 and August 2000) and the cooler months (January and April 2000), suggesting the macroalgal assemblage is structured primarily by zone and secondarily by season. Species richness, percentage cover, biomass, species diversity (H') and evenness (J') were highest on the lower reef flat, reflecting greater complexity in the macroalgal assemblage in this zone. However, species diversity and evenness on the lower reef flat and the reef slope did not show seasonal variations. Species diversity in the upper reef flat decreased in the warmer months due to the dominance of an unknown red alga in October 1999 and Enteromorpha linza in August 2000. The results of ANOSIM tests showed that species structure was different not only between zones but also between seasons, and the SIMPER analyses showed that, in the warmer months, Gracilaria coronopifolia , Enteromorpha linza , Laurencia spp. and Hypnea charoides were the species that separated the lower reef flat assemblage from other assemblages. In the same way, the unknown red alga (for October 1999), Enteromorpha linza (for August 2000), Halimeda spp., Mastrophora rosea and Portieria hornemannii were the species responsible for differences in structure between the upper reef flat and the reef slope. In the cooler months, the species responsible for differences in structures between the upper reef flat and the other two zones were Sargassum spp., Gracilaria coronopifolia , Enteromorpha linza and Padina australis , and those responsible for differences between the upper reef flat and the reef slope were Hypnea charoides , Halimeda spp., Mastophora rosea , Enteromorpha linza and Portieria hornemannii . The present investigation suggests that macroalgal abundance and structure on a coral reef in Nanwan Bay in southern Taiwan have marked spatial zonation and seasonal variations, and Sargassum on the lower reef flat has become the most abundant alga, as compared to 12 years ago.

북극 스발바드 군도 Kongsfjorden의 해조상

Marine benthic flora was investigated in an Arctic bay. Specimens of chlorophyte, phaeophyte, and rhodophyte were collected and examined over the period from July to August 2003 from Kongsfjorden Spitsbergen in Svalbard Islands. A total of 28 genera and 32 species (5 chlorophytes, 18 phaeophytes, and 9 rhodophytes) was identified and described. A green alga Enteromorpha linza(Linnaeus) J. Agardh, a brown alga Asperococcus compresus Griffiths ex Hooker, and three red algae Gracilaria gracilis (Stackhouse) Steentoft et al., Rhodymenia pacifica Kylin and Schizochlaenion rhodotrichum Wynne et Norris were recorded in Svalbard Islands for the first time.

164 Chemical Antiherbivore Defenses of Temperate Green Macroalgae

Many temperate green macroalgae contain secondary meatbolites that provide protection from grazing by some herbivores. These include the production of dopamine hydrochloride by the ulvoid green alga Ulvaria obscura and the production of dimethylsulfoniopropionate (DMSP) by many species of Ulvales and Caulerpales. The dopamine hydrochloride defense was isolated using bioassay‐guided fractionation and is effective against sea urchins (Strongylocentrotus droebachiensis) and littorinid snails (Littorina sitkana). The DMSP activated defense system involves enzymatic cleavage of DMSP into dimethyl sulfide (DMS) and acrylic acid. It is found in many of the Ulvales and several species of Codium in the northeastern Pacific and Australasian regions. Many green algae such as Ulva fenestrata and Enteromorpha linza are avoided by urchins, which are deterred by DMS and acrylic acid in laboratory assays. However, these algae are often preferred foods of snails, which are deterred by DMS and acrylic acid. Snails may preferentially consume ulvoid green algae, despite being deterred by DMS and acrylic acid, because these algae contain relatively high nitrogen concentrations.

180 Relationships Between Water and Sediment Characteristics and Benthic Green Macroalgal Abundance in Yaquina Bay, Oregon: 1999–2002

“Green tides” or blooms of ulvoid green algae are frequent in Yaquina Bay estuary on the central Oregon coast, USA. Measurements of their biomass were made from late spring to early winter in 1999 at six intertidal sites in the estuary, and were continued through the winter of 2002 at two sites that showed the greatest accumulation. The dominant blooming species were the Enteromorpha linza complex, Ulva fenestrata, E. flexuosa, and E. intestinalis. Red and brown algal abundance was negligable. Nutrients in the central channel were monitored, along with incident light and water column absorbence, and sediment temperature. The abundance of benthic amphipods was negatively correlated with the concentration of dissolved sulfides in porewater. However, dissolved sulfide levels were not correlated with green macroalgae biomass. Additional correlations were sought between the variables measured in an effort to suggest or negate major cause and effect relationships. This research is relevant to discerning the effects of eutrophication as a stressor on estuarine processes and could contribute toward an understanding of anthropogenic impacts on biological communities in coastal ecosystems.

Cesium-137 concentrations in marine macroalgae from different biotopes in the Aegean Sea (Greece)

The commonest species of red, brown, and green macroalgae were sampled from a range of biotopes in the Aegean Sea during 1998 for their 137Cs content. Significant differences in 137Cs concentrations were found among different species growing under similar environmental conditions, suggesting that uptake does not follow physical levels but is influenced by allometric parameters and physiological mechanisms. 137Cs content in collected seaweeds were in the descending order: Ulva lactuca>Enteromorpha linza>Gracilaria verrucosa>Ceramium rubrum>Cystoseira barbata. A comparison of the stations studied indicated that the degree of accumulation is also dependent on the geomorphology of the specific area. The west side of Thermaikos Gulf, where the rivers Axios, Aliakmon, and Pinios flow, was highly contaminated as was the Strymonicos Gulf where the river Strymon flows. High cesium concentrations were also observed in algae from Lemnos Island near the mouth of the Dardanelles Channel, most likely due to the horizontal circulation of water masses from the Marmaras Sea to the Aegean Sea resulting in the discharge of 137Cs during the purification process in the Black Sea through the Dardanelles Straits. It is concluded that the general dispersion of 137Cs results from the water circulation regime within the Aegean Sea. Higher levels are present in the northern part of the basin due to current circulation originating from the Black Sea and from outflow of rivers. Levels decrease to the south and east, but increase again to the west of Crete where the Black Sea water mass can be periodically traced.

Marine algae from the Gulf of Santa Clara, Sonora, México

Four sites in the Gulf of Santa Clara, northwestern coast of Sonora, Mexico, were sampled seasonally during 1995–1996. A total of 43 species of marine algae were determined, which are recorded for the first time for the area of study. The families with best representation are: Gracilariaceae and Cladophoraceae, each with 5 species; and Corallinaceae, Rhodomelaceae, and Ulvaceae, each with 3. The highest diversity was found in autumn, the lowest in summer. The sites with the low diversity were Piedras del Burro with 7 species and El Tornillal with 18. These places are broad beaches, composed of sand and with few pebbles. The higher diversity was found at Punta Gorda with 34 species and Piedras de La Salina with 26. These localities are characterized by relatively stable rocky substrates, with some intertidal pools. The most common species regardless to distribution and occurrence over time were: Spyridia filamentosa, Dictyota flabellata, Struveopsis robusta, Cladophora microcladioides and Enteromorpha linza. Rosenvingea antillarum and Cladophora vagabunda represent new records for the Gulf of California. Nine epiphytic species were identified, which were frequently observed on Gelidium crinale, Spyridia filamentosa and Dictyota flabellata.

Effects of solar radiation on the Patagonian macroalga Enteromorpha linza (L.) J. Agardh — Chlorophyceae

The photosynthetic performance of Enteromorpha linza (L.) J. Agardh — Chlorophyceae was determined with a portable PAM instrument in situ and under seminatural radiation conditions in Patagonia, Argentina. Solar radiation was measured in parallel with a three-channel radiometer, ELDONET (Real Time Computer, Möhrendorf, Germany), in three wavelength ranges, UV-B (280–315 nm), UV-A (315–400 nm), and PAR (400–700 nm). The effective photosynthetic quantum yield decreased after 15-min exposure to solar radiation when the thalli were kept in a fixed position but recovered in the subsequent shade conditions within several hours. A 30-min exposure of free floating thalli, however, caused less photoinhibition. The photosynthetic quantum yield of E. linza was also followed over whole days under clear sky, partly cloudy and rainy conditions in a large reservoir of water (free floating thalli) and in situ (thalli growing in rock pools). Most of the observed effect was due to visible radiation; however, the UV wavelength range, and especially UV-B, caused a significant reduction of the photosynthetic quantum yield. Fluence rate response curves indicated that the species is a typical shade plant which showed non-photochemical quenching at intermediate and higher irradiances. This is a surprising result since these algae are found in the upper eulittoral where they are exposed to high irradiances. Obviously they utilize light only during periods of low irradiances (morning, evening, high tide) while they shut down the electron transport chain during intensive exposure. Fast induction and relaxation kinetics have been measured in these algae for the first time and indicated a rapid adaptation of the photosynthetic capacity to the changing light conditions as well as a fast decrease of PS II fluorescence upon exposure to solar radiation. There was a strong bleaching of chlorophyll due to exposure to solar radiation but less drastic bleaching of carotenoids.

ARE BLOOM‐FORMING GREEN ALGAE CHEMICALLY DEFENDED?

Van Alstyne, K. L.Shannon Point Marine Center, Western Washington University, 1900 Shannon Point Road, Anacortes, WA 98221 USAUlvoid green macroalgae, such as Enteromorpha and Ulva, can form large blooms that have deleterious impacts on the local biota. These algae are often assumed to be very palatable for most invertebrate and vertebrate herbivores because they lack obvious physical defenses, and because there have been few reports of their producing chemical defenses. However, in laboratory feeding preference assays, the ulvoid macroalgae Enteromorpha linza and Ulva fenestrata were low preference foods for green sea urchins, Strongylocentrotus droebachiensis. Both these algae and several other species of green algae produce large quantities of dimethylsulphoniopropionate (DMSP), which is enzymatically converted to dimethyl sulfide (DMS) and acrylic acid when the algae are physically damaged. In laboratory bioassays, both DMS and acrylic acid were potent feeding deterrents towards urchins at concentrations that the urchins would be likely to encounter in the field. The precursor in this system, DMSP, was a feeding attractant. Our data provide evidence that DMSP functions as a precursor in an activated defense system in marine macroalgae and suggests a similar function in phytoplankton. The presence of this activated defense system may contribute to the persistence of macroalgal blooms by making these algae unpalatable to some species of herbivores.

PATTERNS OF RECRUITMENT AND DISTRIBUTION OF ULVA AND ENTEROMORPHA POPULATIONS IN A KOREAN INTERTIDAL SHORE

Patterns of recruitment and abundance of Ulva pertusa and Enteromorpha linza in the three locations on the south coast of Korea where green tide frequently occurred were investigated with respect to the substrate profile, temporal and spatial variations, and their persistence. Artificial substrates (10 to 20 cm) were made of a mixture of a piece of granite rock and cement on ceramic tiles. These setting plates, representing different surface texture, were placed horizontally and vertically along the rocky shoreline, and replaced every 1 to 2 months. Both populations showed highly seasonal blooms, with peaks in October, 1998 to February, 1999 and another slight peak was observed in the fall of 1999 only for Ulva. However, the winter peak of 1998 did not appeared in the following year, indicating that a significant year‐to‐year variation existed. Regarding their settlement onto artificial plates with different roughness, Ulva preferred to settle on the rough surface both in the upper and lower intertidal zone; however, this pattern only appeared in the upper zone for Enteromorpha. Vertical distribution of the two populations was well separated; Enteromorpha was more abundant in the upper zone and Ulva in the lower zone. Their seasonal blooms were concomitant with ammonia levels, but occurrence was not well correlated with nitrate and phosphate. The ability of the populations to persist, once blooms occurred, was also distinct; Ulva persisted ca. twice as long as Enteromorpha, having a greater impact in the presence of green tide in this geographical area.

The application of atomic force microscopy to topographical studies and force measurements on the secreted adhesive of the green alga Enteromorpha.

Atomic force microscopy (AFM) enables the topographical structure of cells and biological materials to be resolved under natural (physiological) conditions, without fixation and dehydration artefacts associated with imaging methods in vacuo. It also provides a means of measuring interaction forces and the mechanical properties of biomaterials. In the present study, AFM has been applied for the first time to the study of the mechanical properties of a natural adhesive produced by a green plant cell. Swimming spores of the green alga Enteromorpha linza (L.) J. Ag. (7-10 microm) secrete an adhesive glycoprotein which provides firm anchorage to the substratum. Imaging of the adhesive in its hydrated state revealed a swollen gel-like pad, approximately 1 microm thick, surrounding the spore body. Force measurements revealed that freshly released adhesive has an adhesion strength of 173 +/- 1.7 mN m(-1) (mean +/- SE; n=90) with a maximum value for a single adhesion force curve of 458 mN m(-1). The adhesive had a compressibility (equivalent to Young's modulus) of 0.54 x 10(6) +/- 0.05 x 10(6) N m-2 (mean +/- SE; n=30). Within minutes of release the adhesive underwent a progressive 'curing' process with a 65% reduction in mean adhesive strength within an hour of settlement, which was also reflected in a reduction in the average length of the adhesive polymer strands (polymer extension) and a 10-fold increase in Young's modulus. Measurements on the spore surface itself revealed considerably lower adhesion-strength values but higher polymer-extension values than the adhesive pad, which may reflect the deposition of different polymers on this surface as a new cell wall is formed. The study demonstrates the value of AFM to the imaging of plant cells in the absence of fixation and dehydration artefacts and to the characterisation of the mechanical properties of plant glycoproteins that have potential utility as adhesives.