Ahnfeltiopsis Flabelliformis Research Articles

Morphological and molecular reassessment of three species of the genus Besa (Phyllophoraceae, Rhodophyta) from the Northwest Pacific

ABSTRACT We investigated species referred to as ‘Ahnfeltiopsis flabelliformis’ from the Far Eastern seas of Russia as well as Besa catenata (Yendo) M.S.Calderon & S.M.Boo from Mie Prefecture (Shima Peninsula, Japan, near to its type locality) morphologically and by analysis of sequences of plastid rbcL and mitochondrial COI-5P genes. Morphological and phylogenetic analyses showed that Ahnfeltiopsis flabelliformis does not occur in the Far Eastern seas. All algae previously identified as ‘A. flabelliformis’ from Russian waters belong to two morphologically and genetically distinct species that should be referred to the genus Besa as B. divaricata (Holmes) M.S.Calderon & S.M.Boo and B. japonica (Suringar) A.V. Skriptsova & S.Y.Shibneva, comb. nov. We found an unattached form of B. divaricata and named it as B. divaricata f. ahnfeltioides A.V.Skriptsova & S.Y.Shibneva based on its morphological and ecological features.

Changes in the Structure of the Subtidal Phytocoenosis along the Gradient of the Concentrations of Biogenic Elements in the Sukhoputnaya Bay (Ussuriisky Bay, Sea of Japan)

The modification of the structure of the subtidal phytocoenosis was investigated along the gradient of the concentration of nutrients brought with sewage effluents into the Sukhoputnaya Bay (Ussuriisky Bay, the Sea of Japan). It was shown that an increase in the concentration of dissolved inorganic nitrogen (DIN) from 4.2 to 16.6 μM was followed by a decrease of 1.7 times in species richness, while the relative biomass of opportunistic species increased simultaneously by more than 1.5 times and by more than 5 times for Ulva lactuca. A decrease in the number of dominant species and in the number of layers in the structure simplified the algal phytocoenoses. The complex polydominant multi-layered phytocoenosis of Stephanocystis crassipes–Laurencia nipponica + Ulva lactuca–Ahnfeltiopsis flabelliformis was first substituted for a bidominant two-layered phytocoenosis of Stephanocystis crassipes–Tichocarpus crinitus, and further by a one-layer monodominant phytocoenosis of Ulva lactuca. A comparison of our own and published data allows us to conclude that complex phytocoenoses of perennial macrophytes can develop in water areas with DIN concentrations that do not exceed 15 μM.

Seasonal variations in a polysaccharide composition of Far Eastern red seaweed Ahnfeltiopsis flabelliformis (Phyllophoraceae)

The quantitative and qualitative composition of polysaccharides from red alga Ahnfeltiopsis flabelliformis collected in the Amur Bay (Sea of Japan) from February to December 2009, depending on the water temperature and daily dose of photosynthetically active radiation (PAR), was analyzed. The highest content of polysaccharides was observed in February and November–December at low water temperature and daily PAR dose. The polysaccharide amount produced by the seaweed significantly decreased from March to September and increased from September to November. The main components of the polysaccharides were galactose and 3,6-anhydrogalactose containing sulfate groups. The galactose content was high throughout the studied period (28–42%), 3,6-anhydrogalactose ones in the summer (17.4%) and did not depend on environmental factors. The sulfate group amount was high in April–May and July–August. A statistically significant positive correlation was found between the sulfate group amount in the polysaccharide and the average daily PAR dose in the habitat of seaweed. The dynamics of dry weight accumulation during the year was similar to the polysaccharides. According to IR spectroscopy, the polysaccharides mainly contained disaccharide units of kappa-carrageenans and iota-carrageenans. The polysaccharide from A. flabelliformis collected in June had more regular structure than that in other months.

Structural analysis and cytokine-induced activity of gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis

Gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis was studied. According to FT-IR and NMR spectroscopy data, the polysaccharide was found to be iota/kappa-carrageenan with iota- and kappa-type units in a 2:1 ratio containing beta-carrageenan units and minor amounts of nu- and mu-carrageenans. The HPLC and ESI MS/MS data of enzymatic hydrolysis products revealed that the main components of the polymer chain are iota-carrabiose, iota-carratetraose and hybrid tetra- and hexasaccharides consisting of kappa- and iota-units. Xylose was a substituent of a hydroxyl group at C-6 of 1,3-linked β-d-galactose in the total polysaccharides. It was shown that the ability of carrageenans to increase the synthesis of cytokines depended on their molecular weight. The polysaccharide induced the synthesis of the anti-inflammatory cytokine IL-10, whereas oligosaccharides increased the synthesis of both pro- and anti-inflammatory cytokines at high concentrations.

The decadal changes in the Ahnfeltia bed in the Peter the Great Bay (Sea of Japan): possible causes

The decadal changes (from 1992 to 2005) of a community of unattached red algae in the Sea of Japan dominated by Ahnfeltia tobuchiensis were studied for the first time. The most important changes were an increase in species richness and significant changes in the stock of dominant species in the Ahnfeltia bed accompanied by a drastic decrease in the stock and biomass of the cold-temperate-water species Chondrus armatus, which coincided with a significant increase in the stock and biomass of Ahnfeltiopsis flabelliformis, an alga with warm-temperate-water affinity, while the stock and biomass of A. tobuchiensis did not change considerably. These changes led to the alteration of the algal community. The association co-dominated by A. tobuchiensis and C. armatus was noted in 1992, and by 2005, this association was replaced by the A. tobuchiensis and A. flabelliformis co-dominated association. Possible causes for these changes are discussed. It was concluded that warmer waters may be the basic environmental stress factor playing the central role in changing the community structure of the studied Ahnfeltia bed.

The interspecific relationships of seaweeds and their role in the formation of communities of Ahnfeltia tobuchiensis (Kanno et Matsubara, 1932) Makienko, 1970 (Rhodophyta)

The character and intensity of interspecific relationships between common species of an Ahnfeltia bed community (Ahnfeltia tobuchiensis, Ahnfeltiopsis flabelliformis, Chondrus armatus, and Ptilota filicina) were investigated in relation to light levels and concentrations of dissolved inorganic nitrogen and phosphorus compounds. Growth and photosynthetic rates of seaweeds were measured in mono and co-cultures, as well as in a medium containing the metabolites of attendant species. Under low light conditions, A. tobuchiensis showed the highest competitive ability among the species we studied. The experimental results indicated both negative (exploitative competition, allelopathic inhibition of production processes of a competitor) and positive (stimulation of growth and photosynthesis of accompanying species) relationships between seaweeds. Increased nutrient concentrations and light levels resulted in a substantial reduction in the intensity of interspecific relationships. The dynamic system of positive and negative relationships may regulate the A. tobuchiensis community structure; the intensity of interspecific relationships depends on the availability of resources such as light and nutrients.

Structural peculiarities of polysaccharide from sterile form of Far Eastern red alga Ahnfeltiopsis flabelliformis

KCl-insoluble sulfated polysaccharide from sterile alga Ahnfeltiopsis flabelliformis was investigated. Partial reductive hydrolysis and NMR spectroscopy showed that the polysaccharide comprises disaccharide units of carrabiose only. According to FT-IR-, 1D, 2D NMR spectroscopies and mass-spectrometry this polysaccharide is kappa/beta-carrageenan with ratio of kappa- and beta-types units 3:1 and contains minor amounts of iota- and gamma-carrageenans (precursor of beta-carrageenan). In addition, ESIMS/MS data suggested that xylose (minor amount) is present in the polysaccharide as a substituent one of hydroxyl group of galactose. According to aPTT and PT assays the studied carrageenan affected mostly intrinsic pathway of coagulation, while it effect on the extrinsic pathway is absent.

Comprehensive study of phycobiliproteins and sulfated polysaccharides from the red alga Ahnfeltiopsis flabelliformis

Successive extraction of phycobiliproteins (PBP) by two methods (0.1 M phosphate buffer and 1.5% NaNO3 solution) and polysaccharides from reproductive (cystocarps) and sterile red alga A. flabelliformis was performed. The yield of phycoerythrin (PE) was twice as great for extraction by NaNO3 than by phosphate buffer. The yield of polysaccharides was 1.6 times greater for successive extraction than without preliminary extraction of PBP from the alga. The polysaccharide content in sterile plants was 1.5 times less than in alga with cystocarps regardless of the PBP extraction method. According to IR spectral data, the polysaccharide from sterile plants was κ-carrageenan; from alga with cystocarps, κ,ι-carrageenan.

Spatial distribution of algae in the Ahnfeltia tobuchiensis bed in Amursky Bay (Sea of Japan)

Horizontal and vertical distribution of algae in Ahnfeltia tobuchiensis beds was studied in the area of Mt. Stolovaya in Amursky Bay, Sea of Japan. Thirty-four species of macroalgae (2 species of Chlorophyta, 26 Rhodophyta, and 6 Ochrophyta) were found in the area of study. Two fields of the unattached alga Ahnfeltia were located opposite Mt. Stolovaya; they differed in area, macrophyte stock, number and biomass of attendant species, hydrochemical and light conditions. A monodominant Ahnfeltia tobuchiensis community formed in the southern field and a bidominant community of Ahnfeltia tobuchiensis + Ahnfeltiopsis flabelliformis developed in the northern field. It is suggested that the horizontal distribution of common macrophyte species in the Ahnfeltia beds at Mt. Stolovaya is conditioned by the amount of photosynthetically active radiation (PAR) reaching the surface of the algal bed. Differences in tolerance of Ahnfeltia and attendant species to shadowing and in light conditions across the alga stratum define the vertical distribution of algae within the bed. Chondrus armatus and Ptilota filicina were found mainly in the upper layer of the algal bed. A. tobuchiensis, A. flabelliformis, Chaetomorpha linum, and Coccotylus orientalis extended across the entire thickness of the bed.

The effects of betonicine, floridoside, and isethionic acid from the red alga Ahnfeltiopsis flabelliformis on quorum-sensing activity

A mixture of three compounds (betonicine, floridoside, and isethionic acid) purified from the red alga Ahnfeltiopsis flabelliformis, was reported to have an inhibition activity on bacterial quorum sensing mechanism mediated by Noctanoyl-dl-homoserine lactone (OHL) and the TraR transcriptional activator protein. We subsequently conducted a more detailed investigation of the three compounds using chemically synthesized (betonicine and floridoside) or commercially available (isethionic acid) compounds, individually or in various combinations. When tested alone, none of the three compounds inhibited OHL, but a mixture of floridoside and isethionic acid exhibited a dose-dependent inhibitory effect on the function of OHL. In contrast, betonicine or its isomer exhibited a dose-dependent stimulatory effect, similar to OHL, at concentrations between 10−3 and 10−6 M. These three compounds will be useful for elucidating the interaction between OHL and TraR, and for developing novel bacterial quorum-sensing inhibitors.

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.

동해안 3개 원전 배수로 해조군집의 생태적 특성

The species composition and biomass of marine algae at the discharge canals of three (Gori, Wolseong and Uljin) nuclear power plants on the east coast of Korea were investigated seasonally from February 1992 to October 2000. As a result, 103-107 species of marine algae were found at the discharge canals during the past nine years. In general, algal communities established at the discharge canals were less diverse than those at the intake canals and control sites. 43 species (6 blue-green, 9 green, 10 brown and 18 red algae) of marine algae occurred more than 1/6 frequency and thus can be categorized as warm tolerant species. Among these, two green (Urospora penicilliformis, Cladophora albida), four brown (Sphacelaria divaricata, S. rigidula, Sargassum coreanum, S. fulvellum) and four red algae (Stylonema alsidii, Bangia atropurpurea, Hypnea charoides, Chondria crassicaulis) are recorded as warm tolerant marine algae for the first time in Korea during this study. Enteromorpha compressa, Padina arborescens, Amphiroa zonata and Ahnfeltiopsis flabelliformis were common species found more than 50% frequency at the discharge canals of all three nuclear power plants investigated. Dominant species in biomass were Padina arborescens and Amphiroa zonata. Results showed that, as a whole, the red algae appeared as predominant algal group at the discharge canals of all three nuclear power plants on the east coast of Korea. However, the biomass proportion of dominant algae at the discharge canals of each nuclear power plant varied over the year during the past nine years.