The Seasonal Growth Dynamics of Fucus distichus subsp. evanescens (C. Agardh) H.T. Powell, 1957 (Phaeophyceae: Fucales) in the Avacha Bay (Southeastern Kamchatka)

Russian Journal of Marine Biology - The peculiarities of the linear growth and morphogenesis of the commercial brown alga Fucus distichus subsp. evanescens from the Avacha Bay (southeastern...     

Seasonal variations in the metabolic activity of cells of <Emphasis Type="Italic">Fucus vesiculosus</Emphasis> Linnaeus, 1753 (Phaeophyta: Fucales) from the Barents Sea

The cellular metabolic activity was studied in the brown alga Fucus vesiculosus from the Barents Sea. Several phases of activity of physiological processes in cells of this alga during a 1-year period have been identified. This study shows that the onset and duration of the three main phases of seasonal development of alga, viz., the resting phase, growth, and the accumulation of reserve nutrients, can be determined based on the level and dynamics of the cellular metabolic activity. Each development phase in F. vesiculosus is characterized by a specific rhythm of the daily metabolic activity of cells.     

Elektrophysiologische Untersuchungen am Ei von Fucus serratus: Das Membranpotential

Planta - The transmembrane electric potential difference (PD) between cytoplasm and external medium has been measured on unfertilized eggs and zygotes of the marine brown alga, Fucus serratus. The...     

Comparison of different types of biomasses for copper biosorption

Three biomass, birch wood Betula sp., marine brown alga Fucus vesiculosus, and terrestrial moss Pleurozium schreberi, have been compared as raw materials for preparation of biosorbents for removal of copper ions from diluted water solutions. Small sample doses (0.5 g/100ml) of the biosorbents prepared from alga and moss enabled more than 90% removal of Cu(II) ions from diluted water solutions (5-20mg/l). The sample from sawdust was less effective. A pseudo-second-order rate model properly described the experimental kinetic data for the biosorbents. The maximum sorption capacities (Xm) determined from the experimental equilibrium isotherms by applying the Langmuir model showed that the alga had the best copper-binding ability (Xm=23.4 mg/g), followed by the moss (Xm=11.1mg/g), and the sawdust (Xm=4.9 mg/g). No visible damages or performance losses were detected for the alga and moss after five sorption-desorption cycles using diluted HCl as eluent.     

Effects of Hydrothermal Activity on Metal Accumulation in the Thalluses of the Brown Alga Fucus evanescens in the Kuril Islands

We studied the accumulation of Fe, Mn, Zn, Cd, and Ni in the thalluses of the brown alga Fucus evanescensdepending on the remoteness of the source of the income of metals into the coastal area of Shiashkotan, Yankicha, and Kunashir islands under the effects of recent gas-hydrothermal activities. It has been revealed that the range of the postvolcanic activity effects shows a local pattern and depends on the hydrochemical peculiarities of the source and the hydrodynamic characteristics of the water area.     

The Effects of Polyphenolic Impurities in Fucoidan Samples from the Brown Alga Fucus distichus subsp. evanescens (C. Agardh) H.T. Powell, 1957 on the Embryogenesis in the Sea Urchin Strongylocentrotus intermedius (A. Agassiz, 1864) and on the Embryotoxic Action of Cucumarioside

Russian Journal of Marine Biology - The effects of polyphenolic impurities on the biological activity of fucoidan samples from the brown alga Fucus distichus subsp. evanescens were studied using...     

Quaternary marine macroalgae from Greenland

Four species of brown algae, Sphacelaria arctica, S. plumosa, Desmarestia aculeata , and midribs of a Fucus species have been found in Holocene and interstadial deposits in Greenland. The green alga Chlorochytrium dermatocolax and the red alga Audoui-nella cfr. microscopica are reported for the first time in such deposits. All species are present in the extant flora of marine, benthic algae from Greenland. They are very well preserved and can be identified to species level.     

Sulphate Uptake in Fucus serratus

The brown alga Fucus serratus Linn has been shown to possessan active sulphate uptake system, which is blocked by the metabolicinhibitors DNP and DCCD, but not by the photosystem II inhibitorDCMU. The affinity of the system for sulphate was 5.9 ? 10^–5M, and a monophasic response to external sulphate concentrationwas found in the range 10^–6–10^–3 M. Sulphateuptake was also inhibited by the Group VI anions selenate andchromate. Short-term kinetic experiments showed an initial hyperbolicuptake of for 20 s probably representing diffusion into the intracellular free spaces of the alga, afterwhich sulphate uptake was linear. The intermediates of the sulphateactivating system, APS and PAPS, appeared in the alga after20 s and cysteine after 1 min. The sulphate intermediary metabolicpools were saturated after 2 min, and radioactivity was linearlyincorporated into the sulphated fucan, fucoidan, after 2 min.A chase period of 15 min confirmed that the sulphate activatingsystem APSPAPS occurs in Fucus serratus.The principal metabolic fate of the assimilated sulphate wasesterification to fucoidan (80% of the total ³⁵S present aftera 1 h pulse) and assimilatory sulphate reduction to the sulphuramino acids was a minor pathway in this alga. The turnover ofsulphate in fucoidan was rapid (t_0.5 20 h) and was much higherthan the corresponding turnover of carbon under optimal photosyntheticconditions. This suggested that a preexisting polymer was sulphated;there was also no evidence for sulphated sugar nucleotides inthe short-term kinetic experiments.     

Turnover of the Intracellular Mannitol Pool of Fucus spiralis L. (Fucales, Phaeophyta) during Osmotic Shock

13C {¹H} nuclear magnetic resonance spectroscopy has been usedto study the turnover of the low-molecular weight carbohydratemannitol in the marine brown alga Fucus spiralis L. During incubationof plants in seawater medium with ¹³C enriched bicarbonate,all of the NMR-visible ¹³C appeared in mannitol; no significant¹³C-labelling of laminaran was observed in seawater, in a hypo-salineor in a hyper-saline medium. Pulse-chase experiments showedthat intracellular mannitol was subject to turnover (half-time20 h), the rate of carbon assimilation into mannitol being slightlygreater than the dissimilation rate, possibly due to net mannitolsynthesis during growth. Fucus spiralis was conservative in the use of mannitol as anintracellular osmoticum. In a hypo-saline medium, mannitol showedno substantial change while potassium, the major cellular cation,was reduced. In contrast, mannitol increased substantially overa 12 h incubation period in a hyper-saline medium, whereas potassiumcontent remained constant. Mannitol assimilation and dissimilation rates were not affectedsignificantly by transfer to a hypo-saline medium. The increasedmannitol content of plants incubated in a hyper-saline mediumappeared to be due to a significant increase in the mannitolassimilation rate. Key words: Mannitol, Fucus, Phaeophyta, ¹³C-NMR, osmotic adjustment     

Fucus ‘lignin’: A reassessment

A ‘lignin’ fraction isolated by the Björkman method from the marine brown alga Fucus vesiculosus has been examined by ¹³C NMR and degradative analysis, and shown to consist of polyphloroglucinols identical to those characterized earlier from Fucus. No evidence for the presence of lignin in F. vesiculosus could be found.     

A Comparative Study of Free Amino Acids of the Brown Alga <Emphasis Type="Italic">Fucus vesiculosus</Emphasis> Linnaeus, 1753 from the Intertidal Zone of the Murman Shore,Barents Sea

The free amino-acid contents of the apical and middle parts of the thallus, as well as the receptacles of fertile and juvenile specimens, of the brown alga Fucus vesiculosus collected from seven different biotopes of the Murman shore, Barents Sea have been studied for the first time. The free amino-acid composition of the studied algae specimens was dominated by alanine, along with aspartic and glutamic acid. The distribution of free amino acids in the thallus of Fucus is uneven and depends on the habitat. The free aminoacid contents in the spring vary considerably between different parts of the thallus; however, certain regular patterns of their distribution are observed. A correlation has been found between the level of some individual amino acids in different parts of the thallus of fertile and juvenile algae and the salinity of the seawater.     

The role of hypersalinity in the persistence of the Texas 'brown tide' in the Laguna Madre

A brown tide bloom of the alga Aureoumbra lagunensis was presentwithout interruption in the Laguna Madre of Texas from January1990 through October 1997. This is the longest continual phytoplanktonbloom of which we are aware. Although the factors leading tothe initiation of this bloom have been well documented, thefactors contributing to its persistence are still being investigated.Two physical characteristics of the Laguna Madre may play animportant role: the long turnover time for waters in this coastallagoon (–1 year) and the hypersaline conditions that usuallyexist (40–60 PSU) due to evaporation exceeding precipitation.In this study, we examined the effects of salinity on the growthrates of the brown tide alga and on the growth of one of itsprotozoan grazers. Historical data from before the onset ofthe brown tide provide evidence for the suppression of microzooplanktonpopulations and mesozooplankton growth caused by hypersalinity.The brown tide alga will grow in a remarkably wide range ofsalinities ranging from 10 to 90 PSU. Maximum growth rates areachieved at salinities ranging from 20 to 60 PSU. One commongrazer on the brown tide alga, the heterotrophic dinoftagellateOxyrrhis marina, was found to grow more slowly under hypersalineconditions. The normally hypersaline conditions of the LagunaMadre may, therefore, favor the brown tide alga over other phytoplanktonspecies that do not grow well under hypersaline conditions,and also suppress the growth and feeding rates of potentialgrazers.     

Effect of fucoidan from brown alga <Emphasis Type="Italic">Fucus evanescens</Emphasis> on a formation of TMV-specific inclusions in the cells of tobacco leaves

The effect of fucoidan (1.3; 1.4-α-L-fucan), a sulfated polysaccharide from the brown alga Fucus evanescens on the formation of specific granular and tubular inclusions induced by tobacco mosaic virus (TMV) and consisted presumably of the virus-coded protein components of the viral replicase was investigated in the TMV-infected leaves of tobacco (Nicotiana tabacum L.). In four days after inoculation of the leaves with a TMV preparation (1 mg/ml), the signature of infection in a presence of fucoidan (1 mg/ml) was a preferential formation of intracellular granular inclusions, which were related to early stages of the virus reproduction. When infected leaves were not treated with fucoidan, their cells contained mainly tubular inclusions, which were presumably formed from the granular ones on the last stages of the infection process. These observations demonstrated that fucoidan delayed the development of the TMV-induced infection.     

Phospholipid metabolism in the brown alga, Fucus serratus

The metabolism of phospholipids in the brown alga, Fucus serratus was studied. The major phospholipids of this alga are phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, cardiolipin and phosphatidylcholine. When the time-course of labelling of the lipids from [³²P] orthophosphate was studied, total labelling was approximately linear for 8 hr. All the major classes of phospholipid were labelled. The extent and pattern of labelling were not affected by the presence of proteins synthesis inhibitors phosphatidic acid was highly labelled at short time intervals. Phosphatidylcholine was relatively poorly labelled. The extent and pattern of labelling were not affected by the presence of protein synthesis inhibitors indicating that the enzymes involved in phospholipid synthesis have a rather slow turnover. Incorporation of radioactivity into phosphatidylglycerol was stimulated significantly by light.     

Stage-dependent sensitivity to ultraviolet radiation in zygotes of the brown alga Fucus serratus

Sensitivity to ultraviolet (UV) radiation (UV-A, lambda = 315-400 nm; plus UV-B, lambda = 280-315 nm) of zygotes of the brown alga Fucus serratus L. (Phaeophyta) has been assessed through effects on growth of developing germlings. Different stages of development were distinguished by considering 5 h periods of time after fertilisation. Both the stage of the zygote and the UV radiation condition significantly affected growth of developing germlings. The negative response of growth rate of early stages of the zygotes to UV radiation seemed to be caused by UV-B rather than UV-A radiation, as the lowest relative growth rates were always estimated for germlings developed from zygotes irradiated with UV-B radiation. As regards the stage of the zygote, those germlings that developed from zygotes irradiated at 5-10 h after fertilisation showed the strongest inhibition of growth compared with the other stages. These results point to polarisation as the most UV-sensitive process during the first 24 h of the development of the zygote. A non-linear relationship between the developmental stage of the zygote and the sensitivity to UV radiation is suggested.     

Microbial herbivory on the brown tide alga, Aureococcus anophagefferens: results from natural ecosystems, mesocosms and laboratory experiments

Experiments were conducted with natural plankton assemblages from two areas in Great South Bay (GSB) and the Peconic Bays Estuary System, NY, to compare the rates of growth and pelagic grazing mortality of Aureococcus anophagefferens with co-occurring phytoplankton. We hypothesized that A. anophagefferens would experience low mortality rates by microbial herbivores (relative to feeding pressure on other algae) thus providing it with a competitive advantage within the phytoplankton community. In fact, substantial rates of mortality were observed in nearly every experiment in our study. However, mortality rates of A. anophagefferens were less than intrinsic growth rates of the alga during late spring and early summer in Great South Bay, resulting in positive net growth rates for the alga during that period. This timing coincided with the development of a brown tide in this estuary. Similarly, growth rates of the alga also exceeded mortality rates during bloom development in natural plankton assemblages from the Peconic Bays Estuary System held in mesocosms. In contrast to the situation for A. anophagefferens, growth rates of the total phytoplankton assemblage, and another common picoplanktonic phytoplankter (Synechococcus spp.), were frequently less than their respective mortality rates. Mortality rates of A. anophagefferens in both systems were similar to growth rates of the alga during later stages of the bloom. Laboratory studies confirmed that species of phagotrophic protists that consume A. anophagefferens (at least in culture) are present during brown tides but preference for or against the alga appears to be species-specific among phagotrophic protists. We conclude that two scenarios may explain our results: (1) protistan species capable of consuming the brown tide alga were present at low abundances during bloom initiation and thus not able to respond rapidly to increases in the intrinsic growth rate of the alga, or (2) the brown tide alga produced substance(s) that inhibited or retarded protistan grazing activities during the period of bloom initiation. The latter scenario seems less likely given that significant mortality of A. anophagefferens was measured during our field study and mesocosm experiment. However, even a minor reduction in mortality rate due to feeding selectivity among herbivores might result in a mismatch between growth and grazing of A. anophagefferens that could give rise to significant net population growth of this HAB species. Either scenario infers an important role for trophic interactions within the plankton as a factor explaining the development of brown tides in natural ecosystems.     

Participation of the Green Algae <Emphasis Type="Italic">Ulvaria obscura</Emphasis> in Bioremediation of Sea Water from Oil Products

Participation of green algae in bioremediation of sea water from oil products (OPs) has been studied. Decrease in the content of OPs in water is accompanied by their accumulation by the alga Ulvaria obscura (Chlorophyta). It has been assumed that neutralization of OPs in Ulvaria occurs, similarly to Fucus vesiculosus (Phaeophyta), all over the thallome: destruction of OPs starts on the alga surface by epiphytic hydrocarbonoxidizing bacteria providing absorption and subsequent degradation of OPs by plant cells. The role of macrophytes in bioremediation of coastal areas from OPs is considerably higher than previously supposed.     

Nitrogen content in the brown alga Fucus gardneri and its relation to light, herbivory and wave exposure

Nitrogen is a necessary element for much of seaweed physiology, and is the most common limiting nutrient for marine macroalgae. Therefore, the content of nitrogen in algal tissue is often considered a useful indicator of algal productivity. However, the significance of algal nitrogen content in the field is understudied. We used a factorial manipulation of light and herbivory at three sites in order to evaluate how three factors (light, herbivory, wave exposure) affect the nitrogen content of the brown alga Fucus gardneri. We found that nitrogen content was a function of (1) nitrogen supply via amount of water flow and (2) irradiance, possibly via photoinhibitory effects. This research shows that local effects, by shifting nutrient allocation, can change nitrogen content over spatial scales of centimeters.     

LIPID COMPOSITION OF THE BROWN ALGA FUCUS VESICULOSUS1,2

The lipids of the brown alga Fucus vesiculosus consist of approximately 3.6% hydrocarbons (including carotenes) and sterol esters, 11.8% triglycerides, 4.2% free fatty acids, 10.6% sterols, 15.1% chlorophylls and xanthophylls, 29.9% glycolipids, and 6.5% phospholipids. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol appear to be present and phosphatidylcholine is absent.