Isolation and structure determination of algicidal compounds from Ulva fasciata

Thirty-seven species of seaweeds including 10 Chlorophyta, 13 Phaeophyta, and 14 Rhodophyta collected from the coast of Nagasaki Prefecture, Japan, were screened for algicidal activity against the red-tide phytoplankton Heterosigma akashiwo. The green alga Ulva fasciata (Ulvaceae, Chlorophyta) showed the strongest algicidal activity among the seaweeds tested. Bioassay-guided fractionation of the methanol extract of U. fasciata led to isolation of three algicidal compounds whose structures were determined to be hexadeca-4,7,10,13-tetraenoic acid (HDTA), octadeca-6,9,12,15-tetraenoic acid (ODTA), and alpha-linolenic acid on the basis of spectroscopic information. These polyunsaturated fatty acids (PUFAs) showed potent algicidal activity against H. akashiwo (LC(50) 1.35 microg/ml, 0.83 microg/ml, and 1.13 microg/ml for HDTA, ODTA, and alpha-linolenic acid, respectively), and the result demonstrated the potential of these PUFAs for practical harmful algal bloom control.     

Distribution of Diacylglycerylhydroxymethyltrimethyl-{beta}-alanine (DGTA) and Phosphatidylcholine in Brown Algae

Lipids were analyzed in thirteen species of brown algae collectedat the seashore near Tokyo, Japan. Diacylglycerylhydroxymethyltrimethyl-ß-alanine(DGTA), a recently identified betaine lipid, was found as amajor lipid component in eight species of brown algae examined,namely, Ishige okamurai, Dictyota dichotoma, Pachydictyon coriaceum,Padina arborescens, Hizikia fusiformis, Sargassum horneri, S.ringgoldianum and S. thunbergii. However, phosphatidylcholine(PC) was not detected in any of these algae except I. okamurai.By contrast, PC was found as a major lipid component in fiveother species, namely, Colpomenia sinuosa, Endarachne binghamiae,Scytosiphon lomentarius, Eisenia bicyclis, Undaria pinnatifida.These algae in turn did not contain detectable amounts of DGTA.The fatty acid composition of four selected species, S. lomentarius,U. pinnatifida, D. dichotoma and H. fusiformis, was also studied.The fatty acid components of DGTA in D. dichotoma and H. fusiformiswere similar to those of PC in U. pinnatifida, the major componentsbeing 16:0, 18:2 and 20:46 (also 16:1 in D. dichotoma). (Received December 14, 1990; Accepted April 10, 1991)     

Isolation of protoplasts from edible seaweeds

Protoplasts were isolated enzymatically from three species of Chlorophyta (Enteromorpha linza, Monostroma zostericola andUlva pertusa) with high yield and viability. An enzyme solution appropriate for protoplast isolation from the marine green algae was the following: 2% Cellulase Onozuka R-10, 1.0.M mannitol, pH 6.0. Protoplasts could not be obtained from members of Phaeophyta or Rhodophyta.     

Assessment of the seaweed-seagrass resource of Mararison Island,Culasi, Antique,Philippines*

A bimonthly sampling of the seaweed-seagrass resource of Mararison Island, Culasi Antique, was undertaken over 1 year to assess the species composition, similarity of taxa, and biomass (dry weight [d.w.] g m^?2) at seven localities. A total of 45 species was identified: 17 Chlorophyta, seven Phaeophyta, 15 Rhodophyta, one Cyanophyta and five seagrasses. Except for some Rhodophyta and Syringodium isoetifolium (Ascherson) Dandy, the occurrence of species between stations was not significantly different; however, differences in biomass between sampling time (month) were significant. Identical taxa between stations were determined. The highest (40) and lowest (22) number of species collected were in May and July, respectively. The species were most abundant from March to May (dry months) and sparse from July to September (wet months). The most abundant species were: Sargassum polycystum C. Agardh (399 g m^?2) (Phaeophyta), Dictyosphaeria cav-ernosa (Forsskat) Borgesen (43.1 g m^?2) (Chlorophyta), Acanthopeitis japonica Okamura (97.2 gm^?2) (Rhodophyta) and Thalassia hemprichii (Ehrenberg) Ascherson (1370 g m^?2; seagrass). The Phaeophyta were abundant in March, and the Chlorophyta and Rhodophyta in May, while the seagrasses were abundant in September. Some species occurred only during the dry months: two Phaeophyta, nine Chlorophyta and five Rhodophyta. All the seagrasses were found year-round. Almost all of the seaweeds (39/45) were found associated with seagrass. The number of seaweeds in Mararison Island was higher than for seagrasses but the total biomass of the latter was much higher than the combined biomass of the seaweeds.     

浙江马鞍列岛海域潮间带底栖海藻分布特征

2007年3—7月对浙江马鞍列岛海域潮间带底栖海藻进行了调查,初步查明该海域潮间带底栖海藻的组成、分布情况和温度属性,并利用相似性指数（S_c）和相对重要性指数（IRI_c）分析了调查海域潮间带底栖海藻的优势种组成.结果表明：调查海域采集到的31种海藻隶属于3门24属,其中绿藻门5属7种,褐藻门5属8种,红藻门14属16种;在波浪和潮汐作用下,潮间带出现局限分布种和选择性分布种,孔石莼、鼠尾藻等在调查岛礁区域广有分布;红藻门种类在调查海域的出现频率为61.1%,为优势门类,绿藻门种类在该海域的总体水平分布基本呈均匀状态;81%的调查种类分布在低潮带,其中包括一些中潮带延伸种类,中、低潮带的海藻组成相似性值为0.47,并且中、低潮带的生境趋同效果大于高、中潮带.马鞍列岛潮间带底栖海藻具有明显的垂直分带现象,温水性种类占绝对优势,优势种多为暖温性种.该海域底栖海藻属于暖温带-亚热带过渡型海洋植物区系.     

Antimicrobial activity of some macroalgae of the Veracruzano Reef System (SAV), Mexico

The study of macroalgae antimicrobial agents is limited to Mexico and scarce in the Veracruzano Reef System (SAV). It is necessary to devote efforts towards this field of applied phycology. The aim was to evaluate the antimicrobial activity of some phyla of Rhodophyta, Chlorophyta and Ochrophyta from SAV. Methanolic extracts from 23 marine macroalgae species (7 Chlorophyta, 4 Phaeophyta and 12 Rhodophyta) from the Veracruzano Reef System (SAV) (Mexico) were evaluated for antimicrobial activity. Antibacterial and antifungal activity were assessed by agar diffusion and agar dilution methods. The differences between mean values obtained for experimental groups was done by analysis of variance (ANOVA multifactorial model), p-values of 0.001 or less were considered statistically significant. Two new records are recognized for SAV (Laurencia gracilis and Sebdenia flabellata) and Compsothamnion thuioides for the Gulf of Mexico coasts. 16 species showed antibacterial activity, of which Caulerpa sertularioides, Ulva lactuca and Laurencia obtuse had significant activity on Gram-positive bacteria. 43.7% belong to the phyla Chlorophyta (7 species), 50% Rhodophyta (8 species) and 6.25% Ochrophyta (1 species). This indicates that the extracts of the algae of the Rhodophyta and Chlorophyta are the ones that showed the greatest activity. Regarding the yeasts, 16.6% of the total algae collected were active in the different yeast strains. 43.7% belongs to Chlorophyta species and for Rhodophyta were 60%. The macroalgae with the highest antifungal activity were: Cymopolia barbata, Ulva lactuca and Laurencia gracilis. The macroalgae of the Veracruzano Reef System present antimicrobial activity. This study is the first investigation of macroalgae's bioactive components from SAV, where they could be sources for future medical applications.     

New records of Malaysian marine algae

Checklists of the marine algae of Malaysia have been published. The last checklist included the marine algae of Singapore. The checklist recorded 212 taxa for the region. This paper lists an additional 7 taxa of Chlorophyta, 18 taxa of Rhodophyta and 5 taxa of Phaeophyta, which had been left out of the last checklist. These include marine algae from Pulau Pinang, Pulau Redang and Pulau Sibu. In addition, new records of Cyanophyta (2 species), Chlorophyta (4 species), Rhodophyta (10 species) and Phaeophyta (3 species) are reported.     

Enriching marine macroalgae with eicosatetraenoic (arachidonic) and eicosapentaenoic acids by chilling

Summary Twelve macroalgae belonging to the Chlorophyta, Phaeophyta and Rhodophyta were collected from the Arabian Gulf. Field samples and samples that were first incubated at 5° C and 24° C in the light for 1 week were analysed for lipids and fatty acids. The lipid contents varied according to the macroalga and, within the Chlorophyta and Phaeophyta, some representatives accumulated more lipids at 5° C and others at 24° C. All samples of algae had similar lipid composition with only quantitative differences. The temperature did not have a common effect on the lipid composition of representative algae, although changes in the relative concentration of specific classes were recorded. The Phaeophyta and Rhodophyta were as a rule richer than the Chlorophyta in eicosatetranoic (20:4) and eicosapentaenoic (20:5) but poorer in linolenic (18:3) acids. In most of the algae, incubation at 5° C was associated with lowering the proportion of palmitic acid (16:0) in the total lipids, and, but only in the Phaeophyta and Rhodophyta, increasing the concentration of 20:4 and 20:5. These polyunsaturated fatty acids occurred in high levels in monogalactosyldiacylglycerols (MGDG) and digalactosyldiacylglycerols (DGDG) of the Phaeophyta and Rhodophyta but not the Chlorophyta, the MGDG and DGDG of which were rich in 18:3 and hexadecatrienoic acid (16:3). Offprint requests to: R. H. Al-Hasan     

Distribution of carbonic anhydrase in British marine macroalgae

Summary Thirty-four species of marine macroalgae from around St. Andrews, Scotland, have been assayed for their external activity and thirty-three species for their total activity of carbonic anhydrase. Activity was detected in all the Rhodophyta tested apart from Chondrus crispus, but was absent in Codium fragile, Enteromorpha sp. and Monostroma fuscum (Chlorophyta), and Alaria esculenta, Laminaria digitata, L. saccharina and L. hyperborea (Phaeophyta). Total activity of carbonic anhydrase per unit fresh weight tended to be higher in the Rhodophyta than in the Chlorophyta or Phaeophyta. External activity was present in two of the six Chlorophyta, four of the twelve Phaeophyta and four of the sixteen Rhodophyta tested. On average, when present, external carbonic anhydrase activity represented 2.7% of the total activity. A relationship was found between total carbonic anhydrase activity and habitat. Species from the high intertidal and the low-light subtidal habitats had significantly higher activity than species from the mid and low intertidal, rockpools, or high-light region of the subtidal. External carbonic anhydrase activity did not vary significantly with habitat. There appeared to be no strong relationship between carbonic anhydrase activity and the ability of a species to use HCO _- ³ in photosynthesis under water.     

Epiphytic dinoflagellates associated with ciguatera in the northwestern coast of Cuba

The spatial and temporal abundance of epiphytic dinoflagellates associated with ciguatera was studied over two annual cycles (March 1999 to March 2000 and March 2001 to March 2002) in the northwestern coast of Cuba. From 14 species of macroalgae (Phaeophyta, Chlorophyta, and Rhodophyta), 1340 samples were obtained identifying seven species as potentially noxious; five of them are new reports for Cuba's phytobenthos: Prorocentrum belizeanum Faust, P. concavum Fukuyo, P. mexicanum Tafall, Coolia monotis Meunier, and Ostreopsis lenticularis Fukuyo. ANOVA/MANOVA analysis showed significant spatial differences: lower cell abundance near the shoreline adjacent to a river inlet and higher cell abundance in the deepest area. Prorocentrum lima (Ehrenberg) Dodge 1975 was found mainly on Phaeophyta followed by Chlorophyta and Rhodophyta. Gambierdiscus toxicus was found mainly on Phaeophyta followed by Rhodophyta and Chlorophyta. All the species reported in the study area were mainly on Padina spp. (Phaeophyta). Acanthophora spicifera (Rhodophyta) did not host dinoflagellate species. Environmental conditions in summer (higher temperature, more nutrients, greater water transparency, and low wind intensity) are suitable for macroalgae development, which serves as a substrate for potentially harmful dinoflagellates, and possibly the main vector for spreading ciguatera along the coast of Cuba.     

SEAWEED ABUNDANCE AND DIVERSITY IN HIGH ENERGY AND LOW ENERGY AREAS AT PORT ARANSAS,TEXAS JETTIES

Agan, J. C. & Lehman, R. L. Department of Physical and Life Sciences, Texas A&M University-Corpus Christi 6300 Ocean Dr., Corpus Christi, TX 78412 USA Benthic algal sampling from high and low energy zones at a selected site on the south jetty at Port Aransas, Texas was completed between April 1999 and February 2000. Species composition and seasonal periodicity in relation to temperature and salinity fluctuations were determined. Dominant plants throughout the year included Bryocladia cuspidata, Bryocladia thyrsigera, Gelidium pusillum, Centroceras clavulatum, Ulva fasciata, and Padina gymnospora. The Rhodophyta dominated species coverage, along with biomass accumulation, although Chlorophyta species accrued the greatest biomass on the high energy side in April and June sampling. Chlorophyta are important to benthic coverage and biomass in the shallowest of waters, despite being fewer in species richness. Phaeophyta species including Petalonia fascia, Hincksia mitchelliae, and Ectocarpus siliculosus were found only during the cooler months. Padina gymnospora was the one exception as it was collected year-round. Results indicate that a greater Rhodophyta abundance was found on the channel side (low energy), where as, the surf side (high energy) contained a greater Chlorophyta abundance. Phaeophyta abundance for both high and low energy sites were comparable possibly due to the greater depth of water in which they are located. Little variance occurred in average biomass accumulation throughout the year. Highest biomass was in August (216.613g dry weight) with lowest occurring in April (107.4205g dry weight).     

Preparation of High Yields of Algal Protoplasts Using Buccal Juice of Sea Hare and Commercial Cellulase

Buccal juice of the sea hare Aplysia juliana was found to degrade algal polysaccharides. The optimal enzyme composition for protoplast preparation from Undaria pinnatifida was protein at 48 μg/ml buccal juice from sea hare, 10 mg/ml cellulase Onozuka-RS, 0.4 M NaCl, 0.8 M sorbitol, 2 mg/ml dextran sulfate sodium salt, and 1 μl/ml 2-mercaptoethanol in 10 mM MES buffer (pH 6.0). Protoplasts of Eisenia bicyclis, Endarachne binghamiae (Phaeophyta), and Ulva pertusa (Chlorophyta) could also be prepared in a similar manner. Yields of these protoplasts were about 10⁷ cells per gram of fresh weight alga. Received January 26, 1998; accepted September 17, 1998.     

SEAWEED ABUNDANCE AND DIVERSITY IN HIGH ENERGY AND LOW ENERGY AREAS AT PORT ARANSAS,TEXAS JETTIES

Agan, J. C. & Lehman, R. L. Department of Physical and Life Sciences, Texas A&M University-Corpus Christi 6300 Ocean Dr., Corpus Christi, TX 78412 USA Benthic algal sampling from high and low energy zones at a selected site on the south jetty at Port Aransas, Texas was completed between April 1999 and February 2000. Species composition and seasonal periodicity in relation to temperature and salinity fluctuations were determined. Dominant plants throughout the year included Bryocladia cuspidata, Bryocladia thyrsigera, Gelidium pusillum, Centroceras clavulatum, Ulva fasciata, and Padina gymnospora. The Rhodophyta dominated species coverage, along with biomass accumulation, although Chlorophyta species accrued the greatest biomass on the high energy side in April and June sampling. Chlorophyta are important to benthic coverage and biomass in the shallowest of waters, despite being fewer in species richness. Phaeophyta species including Petalonia fascia, Hincksia mitchelliae, and Ectocarpus siliculosus were found only during the cooler months. Padina gymnospora was the one exception as it was collected year-round. Results indicate that a greater Rhodophyta abundance was found on the channel side (low energy), where as, the surf side (high energy) contained a greater Chlorophyta abundance. Phaeophyta abundance for both high and low energy sites were comparable possibly due to the greater depth of water in which they are located. Little variance occurred in average biomass accumulation throughout the year. Highest biomass was in August (216.613g dry weight) with lowest occurring in April (107.4205g dry weight).     

Acquisition of species-specific perfume blends: influence of habitat-dependent compound availability on odour choices of male orchid bees (Euglossa spp.)

The mechanisms by which algae disperse across space on coral reefs are poorly known. We investigated the ability of four common Caribbean herbivorous fish species to disperse viable algal fragments through consumption of macroalgae and subsequent defecation. Fragments of all major algal taxa (Phaeophyta, Rhodophyta, and Chlorophyta) were found in 98.7 % of the fecal droppings of all fish species; however, the ability to survive gut passage and reattach to a substrate differed between algal taxa. While survival and reattachment approached zero for Phaeophyta and Chlorophyta, 76.4 % of the fragments belonging to the group Rhodophyta (mostly species in the order Gelidiaceae) survived gut passage, and were able to grow and reattach to the substrate by forming new rhizoids. Our results thus show that Gelidid algal species are dispersed by swimming herbivores. While the relative contribution of this mechanism to overall algal dispersal and recruitment in a wider ecological context remains unknown, our findings illustrate a previously undescribed mechanism of algal dispersal on coral reefs which is analogous to the dispersal of terrestrial plants, plant fragments, and seeds via herbivore ingestion and defecation.     

STEROL PROFILES IN 18 MACROALGAE OF THE PORTUGUESE COAST1

The sterol profiles of dominant macroalgae occurring in the western Portuguese coast were evaluated. An analytical procedure, involving alkaline hydrolysis and extraction followed by separation by reversed‐phase HPLC–diode array detection (HPLC–DAD), was optimized for the study of their sterols composition. The validated methodology is short in analysis time (as the compounds are determined in <20 min), sensitive, reproducible, and accurate. It was then successfully applied to the determination of campesterol, cholesterol, desmosterol, ergosterol, fucosterol, stigmasterol, and β‐sitosterol in 18 species (three Chlorophyta, five Rhodophyta, and 10 Phaeophyta). The profiles obtained for the several macroalgal species were considerably different. C29 sterols were predominant in Phaeophyta and Chlorophyta (71%–95% of total sterol content), while in Rhodophyta cholesterol content is significantly higher (34%–87%). Among the studied species, Asparagopsis armata Harv. contained the lowest sterol amount (555 mg · kg^?1 dry weight), and Cystoseira tamariscifolia (Huds.) Papenf. the highest one (6,502 mg · kg^?1 dry weight). Data obtained may be helpful in identifying suitable marine sources of sterols, with potential applications in the food and pharmaceutical industries.     

Characterization of tidal pool algae in the Mexican Tropical Pacific coast

Tidal pools in the Mexican Tropical Pacific coast have received relatively little attention in spite of their considerable richness in species and wide distribution in the region.This paper presents the first characterization of the algal flora of this region. It analyzes the number and composition of species of the tidal pools of six localities with regard to geographical distribution and its seasonal variations as well as tidal level. 97 species are reported, 25 Chlorophyta, 23 Phaeophyta, 34 Rhodophyta and 15 Cyanophyta.Of that total of species, 63% were found in one locality, 23.7% in two, 11.3% in three and 1 % in 4 or 5 localities. Not one species was common to all of the pools.The highest number of species was found on pools of the middle and low intertidal where the Chlorophyta, Rhodophyta and Phaeophyta were the most abundant algae. Cyanophyta was more common in the supralittoral and high intertidal pools.     

The Fatty Acid Composition of Glycolipids of Marine Macrophytes

Specific patterns of fatty acid distribution in individual glycolipids were found for marine macrophytes from different phyla: Palmaria stenogona (Rhodophyta), Undaria pinnatifida (Phaeophyta), Ulva fenestrata (Chlorophyta), and Zostera marina (Magnoliophyta). In P. stenogona and U. fenestrata, polyunsaturated fatty acids with maximum unsaturation were concentrated in monogalactosyldiacylglyceride, whereas in U. pinnatifida and Z. marina they were also localized in digalactosyldiacylglyceride. For all species investigated, the highest concentration of saturated and monounsaturated fatty acids was found in sulfoquinovosyldiacylglyceride; however, this lipid from Z. marina also had high contents of 18 : 2n-6 and 18 : 3n-3 acids.     

Nutritional value of selected macroalgae

Macroalgae are traditionally used in human and animal nutrition. Their protein and fiber content have been widely studied and differ according to the species, their geographic origin and their seasonal conditions. In addition to their value for human nutrition, seaweeds have multiple therapeutically applications (e.g., weight control, hypocholesterolemic, antioxidant and antitumor activities, others) and, in general, contribute and promote human health. In the archipelago of the Azores, the consumption of seaweeds is widespread and accepted as a common practice in some islands. This work is aimed at providing information on the protein and fiber content of the locally consumed species, to promote this regional food product that can be potentially profitable from the biotechnology and commercial perspective, and also benefit public health, particularly, taking into account the low level of marine pollution in the Azores archipelago. Protein and fiber content of eight seaweeds (Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea, Sphaerococcus coronopifolius, and Gelidium microdon, Rhodophyta; Cystoseira abies-marina and Fucus spiralis, Phaeophyta; Ulva compressa, Chlorophyta) were determined using the Kjeldahl method and the Weende method, respectively. The protein content ranged from 6.81 to 26.62 of dry weight for C. abies-marina and U. compressa, respectively. Fiber content was generally higher as compared with that in seaweeds from other origins and ranged from 33.82 to 63.88 for O. pinnatifida and F. spiralis, respectively.     

Fatty acid composition of ten marine algae from australian waters

Detailed fatty acid analyses are reported for ten benthic algae from Australian waters of which the data for Cladophora fascicularis (Chlorophyta); Polysiphonia pungens, Porphyra sp., Centroceras clavatum (Rhodophyta); Hormosira banksii, Ralfsia sp., and Dictyota dichomota (Phaeophyta) are presented for the first time. The analyses report the exact molecular structure of component acids which is essential for taxonomic and food chain studies. The acid 16:4ω3 could be taxonomically distinguishing for species of the Chlorophyta. The occurrence of cis-vaccenic acid (18:1ω7) in the algae reported here suggests a distribution in marine benthic algae which is wider than hitherto realised, with particular taxonomic importance for Chlorophyta species in which it occurs in high levels. Corallina officinalis was found to contain the non-methylene interrupted acids 20:2 and 22:2.