Effects of a commercial extract of the brown alga Ascophyllum nodosum on the biomass production of Kappaphycus alvarezii (Doty) Doty ex P. C. Silva and its carrageenan yield and gel quality cultivated in Brazil

Despite of its success, the carrageenan industry has had to cope with difficulties due to epiphyte infestations and diseases known as ice-ice. Some promising results in respect of biomass production, carrageenan yield, and protection epiphytes were obtained using a powdered extract of the brown alga Ascophyllum nodosum in Kappaphycus alvarezii seedling production. This study focused on the effects of the A. nodosum extract on the treatment of K. alvarezii cultivated on commercial floating rafts not only to evaluate improvements demonstrated in vitro but also the effects on the quality of the carrageenan. The seedlings were treated in an A. nodosum extract solution and placed alongside their controls on commercial floating rafts using the tubular net technique. Daily growth rate, carrageenan yield, gel strength, and gel viscosity were obtained over 20 and/or 40 days. After 20 days, daily growth rates showed no significant difference (p?=?0.44), while the carrageenan yield was higher in samples that were treated with the A. nodosum solution (p?<?0.001). After 40 days, both daily growth rate (p?=?000.7) and carrageenan yield (p?=?0.009) were higher in treated samples; however, gel strength was higher in control samples (p?=?0.03) as viscosity was also highest in the samples which had not been treated (p?<?0.001). The use of the A. nodosum extract treatment on the cultivation in situ of K. alvarezii was positive since after 40 days when the daily growth rate and carrageenan yield increased. In spite of the negative effect on the quality of the semi-refined carrageenan, the values were within commercial standards.     

A vanadium-dependent bromoperoxidase in the marine red alga Kappaphycus alvarezii (Doty) Doty displays clear substrate specificity

Bromoperoxidase activity was initially detected in marine macroalgae belonging to the Solieriaceae family (Gigartinales, Rhodophyta), including Solieria robusta (Greville) Kylin, Eucheuma serra J. Agardh and Kappaphycus alvarezii (Doty) Doty, which are important industrial sources of the polysaccharide carrageenan. Notably, the purification of bromoperoxidase was difficult because due to the coexistence of viscoid polysaccharides. The activity of the partially purified enzyme was dependent on the vanadate ion, and displayed a distinct substrate spectrum from that of previously reported vanadium-dependent bromoperoxidases of marine macroalgae. The enzyme was specific for Br- and I- ions and inactive toward F- and Cl-. The K(m) values for Br- and H2O2 were 2.5x10(-3) M and 8.5x10(-5) M, respectively. The halogenated product, dibromoacetaldehyde, that accumulated in K. alvarezii was additionally determined.     

Callus ontogeny of the Kappaphycus alvarezii (Rhodophyta, Gigartinales) brown tetrasporophyte strain

This study analyzes the callus ontogeny of the Kappaphycus alvarezii brown strain tetrasporophyte using micropropagation and tissue culture. Calli were induced from axenic explants and grown for 2 months. Ontogenic analysis was made in explants collected from days?7 to 60 of culture and observed under light and transmission electron microscopy (TEM). At the end of the experimental period, 60-day samples were also analyzed by confocal microscopy. Formation of calli was initiated in the first week from medullary and cortical cells of the explant region in air contact. Alterations in the apical region of the cells were observed in TEM as cell wall thickening, proliferation of convoluted membranes, increased number of mitochondria and chloroplast alterations, indicating the dedifferentiation of these cells. Throughout the experiment, the thick cell wall of the cells which compose callus filaments showed the presence of acidic polysaccharides, suggesting a large amount of carrageenan and neutral polysaccharides. The cytoplasm showed the following main characteristics: large amount of starch grains, presence of chloroplasts with altered plastoglobules, as well as disorganized thylakoids, presence of several convoluted membranes, and vacuoles. These filaments maintained their uniseriate organization and irregular branching with many intercellular connections between them. Despite the initial stress caused by explant isolation and the beginning of callus formation, results showed that filaments were capable of reorganization and development, retaining their dedifferentiated cells, which, in turn, strongly suggested the potential of callus-based micropropagation.     

Seasonal variation in growth and carrageenan yield in cultivated Kappaphycus alvarezii (Doty) Doty on the coastal waters of Ramanathapuram district,Tamil Nadu

Kappaphycus alvarezii, a kappa carrageenan yielding red seaweed, was cultivated in Indian subtropical waters on the Palk Bay side of Bay of Bengal in Ramanathapuram district, Tamil Nadu, at three different sites: Vedalai, Munaikadu, and Thonithurai, for 1 year from April 2011 to March 2012. The maximum crop yields of 416 ± 51 and 550 ± 41 FW raft^?1 were recorded at Vedalai and Munaikadu, respectively, in December 2011, whereas a maximum of 326 ± 49 FW raft^?1 was recorded at Thonithurai in April 2011. Similarly, the maximum daily growth rates (DGRs) of 4.30 ± 0.51 % and 4.92 ± 0.40 % were obtained at Vedalai and Munaikadu, respectively, in December 2011, and 3.76 ± 0.48 % was recorded at Thonithurai in April 2011. Variations in environmental parameters like seawater temperature, salinity, nitrate, and phosphate were found to influence the growth of the seaweed. The maximum carrageenan content as a percentage of dry weight was 29.30 ± 0.61 % (Vedalai), 31.00 ± 0.71 % (Munaikadu), and 29.10 ± 1.12 % (Thonithurai) in March 2012. The data on moisture content (%), clean anhydrous weed/salt ratio, and carrageenan yield obtained in this study fulfilled those of international standards. Further, the results indicated that large-scale cultivation by either NGOs or self-help groups (SHGs) may be taken up along the coastal waters for the benefit of the poverty-stricken coastal people as their livelihood, as the growth rate obtained in this study compared well with that recommended for commercial cultivation elsewhere.     

Effect of epiphytism on reproductive and vegetative lateral formation in the brown, intertidal seaweed Ascophyllum nodosum (Phaeophyceae)

In the brown alga Ascophyllum nodosum (L) Le Jolis, a common species on sheltered Northern temperate rocky shores, gametes are produced in receptacles that emerge from small depressions (lateral pits) along the branched frond. These lateral pits are also the preferred settling site for the obligate epiphyte Polysiphonia lanosa (L) Tandy. Therefore, epiphytism can be expected to interfere with host reproductive output. The present study investigated the potential impact of the epiphyte on A. nodosum in two series of laboratory experiments that measured: (i) the direct shading of the host plant underneath an epiphyte canopy; and (ii) the development of receptacles in clean and epiphytised A. nodosum segments (excised from individual fronds) over a 6 month period. These experiments showed that light reaching emerged fronds underneath a dense epiphyte cover was reduced by 40%, and this was independent of the degree of desiccation the epiphyte experienced. Concurrently, in the growth study with epiphytised A. nodosum segments (segments with one clean and one epiphytised lateral pit) total receptacle biomass per epiphytised fragment was significantly reduced compared with clean segments (0.52 g and 1.25 g per gram of frond segment, respectively), although this effect was only significant in A. nodosum from sheltered shores. However, expressed as biomass per lateral pit, receptacle biomass in the remaining clean lateral pits in epiphytised segments was significantly increased in segments from both shores, demonstrating that A. nodosum can at least partially compensate for the loss of production resulting from epiphytism.     

In vitro cultivation of three <Emphasis Type=Italic>Kappaphycus alvarezii</Emphasis> (Rhodophyta,Areschougiaceae) variants (green,red and brown) exposed to a commercial extract of the brown alga <Emphasis Type=Italic>Ascophyllum nodosum</Emphasis> (Fucaceae,Ochrophyta)

Diseases such as “ice-ice” and “goose bumps” are responsible for loss of almost 70% of infected Kappaphycus production. To improve the growth of K. alvarezii and reduce the impact of diseases, the effect of the commercial Ascophyllum nodosum extract was tested. Five grams of apical branches of each K. alvarezii variant (n = 6) were bathed at different extract concentrations (e.g., 5, 10, 15, 20, 25, and 30 g L⁻¹) for 1 hour. To test the effect of the extract on epiphytes apical tips were not cleaned. After 2 weeks, the epiphytes such as Cladophora sp. and Ulva sp. disappeared. Polysiphonia subtilissima survived but its appearance was weak. The highest K. alvarezii growth rates were observed at extract concentrations of 15 and 20 g L⁻¹ (p < 0.001), almost double the expected for a 45-day production cycle used at Sepetiba Bay, Brazil. These results show that the extract was efficient at improving the growth of K. alvarezii and reducing the presence of some epiphytes.     

The effect of a liquid seaweed extract from Ascophyllum nodosum (Fucales,Phaeophyta) on the two-spotted red spider mite Tetranychus urticae

This paper presents evidence from an initial trial in favor of claims that the liquid seaweed extract of Ascophyllum nodosum, marketed in the UK as Maxicrop, can reduce numbers of the two-spotted red spider mite Tetranychus urticae on crop plants. Seven applications of Maxicrop Triple over 20 days significantly suppressed the population build-up of two-spotted red spider mites on treated strawberry plants (Fragaria sp. var. Redgauntlet) raised under high polythene tunnels as compared to untreated controls.     

A (17)O NMR study of peroxide binding to the active centre of bromoperoxidase from Ascophyllum nodosum

The (17)O NMR of bromoperoxidase in Tris buffer at pH 8 treated with (17)O-enriched H2O2 reveals direct binding of peroxide to active site vanadium both in the symmetric and asymmetric modes, the latter possibly due to hydroperoxide. In addition, non-active site HVO2(O2)2(2-) is detected. The results are counter-checked with NMR data on peroxovanadium model compounds.     

The sustainable harvesting of Ascophyllum nodosum (Fucaceae, Phaeophyceae) in Ireland, with notes on the collection and use of some other brown algae

Ireland has a long history of seaweed utilisation, with accounts of its use as a food dating to at least the twelfth century. Arramara Teoranta (literally “Seagoods Ltd.”) was established by the Irish Government in the late 1940s to continue the long tradition of sustainable seaweed harvesting in the west of Ireland, which began with kelp ash production from kelp kilns around 1700 and which continued sporadically until 1948. Initially, Arramara purchased dried sea rods (Laminaria hyperborea) and kelp fronds (mostly Saccharina latissima) and these were exported for alginate production in Scotland. Kelps were gradually replaced by Ascophyllum nodosum, a perennial wrack found in the intertidal of the North Atlantic and which is particularly common on sheltered shores in the west of Ireland. This wrack has been cut sustainably by hand in Ireland since at least the late 1940s. Figures for annual production from the main purchaser, Arramara, show that 2,000–7,000 dry weight tons (about 8,000–28,000 wet tons) have been cut in Ireland each year from 1964 to date. Whilst exports for alginate production ceased in 2009, 5,000–6,000 dry weight tons are currently being produced for the animal feed, horticulture, aquaculture, and cosmetics markets.     

Effect of moderately low temperatures (-30 C to -70 C) on the permeability of erythrocyte membranes

The barrier properties of reconstituted and native erythrocyte membranes frozen to -30, -40 or -70 degrees C and stored for a month were studied. The release of markers, namely haemoglobin molecules, [14C] sucrose and K+ ions from cells and membrane structures was measured. The main changes in the barrier function of ghosts and cells have been found to be due to freeze-thawing rather than to storage conditions. Glycerol, a cryoprotectant, appeared to stabilize the barrier properties of erythrocyte membranes for haemoglobin molecules, [14C] sucrose and to a lesser extent for K+ ions. The cryoprotective effect of glycerol has been shown to be considerably greater towards erythrocytes ghosts than to native erythrocytes.     

The aqueous extract and powder of the brown alga Dictyota dichotoma (Hudson) differentially alleviate the impact of abiotic stress on rice (Oryza sativa L.)

Physiology and Molecular Biology of Plants - Algal supplements can improve crop productivity and afford protection against abiotic stress by virtue of their rich content of plant nutrients and...     

Investigation of the application of Acadian Marine Plant Extract Powder (AMPEP) to enhance the growth, phenolic content, free radical scavenging, and iron chelating activities of Kappaphycus Doty (Solieriaceae, Gigartinales, Rhodophyta)

An optimization study on concentration (viz. 0.01, 0.1, and 1.0 g L^?1) and dipping time (i.e., 30 and 60 min) was conducted on three different color morphotypes (i.e., reddish brown, yellowish brown and purple) of the commercial carrageenophyte Kappaphycus alvarezii (Doty) Doty. The study tested the efficacy of Acadian Marine Plant Extract Powder (AMPEP) on the growth rate and occurrence of macro-epiphytes from August to November, representing the wet season of the Philippines. The optimum concentration and dipping time were obtained at 0.1 g L^?1 and 30 min, respectively. These optimum parameters were then further verified in a commercial nursery using the yellowish brown morphotype. In another experiment, K. alvarezii (tambalang purple morphotype) and Kappaphycus striatum (Schmitz) Doty (sacol green morphotype) with, and without, AMPEP dippings were tested for their total phenolic content, free radical scavenging and iron chelating activities. Seaweed dipped in AMPEP demonstrated higher growth rates than the control. Lower concentrations (i.e., 0.01-0.1 g L^?1) and shorter dipping time (e.g., 30 min) produced higher growth rates than the highest concentration (1.0 g L^?1) and longer (60 min) dipping time. The presence of macro-epiphytes such as filamentous Ulva did not adversely affect the robust growth of the three color morphotypes of K. alvarezii. The lowest and highest growth rates obtained in a commercial seaweed nursery using the optimum concentration and dipping time of AMPEP were observed in July and January with 0.8% and 6.7% day^?1, respectively. The antioxidant content of K. alvarezii (tambalang purple) and K. striatum (sacol green) responded differently to AMPEP dipping. The changes in total antioxidant activity followed almost the same trend as in phenolic content, in both K. alvarezii (tambalang purple) and K. striatum (sacol green), whereas, the iron chelating ability of both seaweeds with and without AMPEP dipping varied monthly. The results obtained for the use of AMPEP dips for commercial Kappaphycus cultivation demonstrated an effective management tool for improved farming protocols.     

Assignment of the human TYRP (brown) locus to chromosome region 9p23 by nonradioactive in situ hybridization.

The TYRP (brown) locus determines pigmentation and coat color in the mouse. The human homolog of the TYRP locus has been recently identified and shown to encode a 75-kDa transmembrane melanosomal glycoprotein called gp75. The gp75 glycoprotein is homologous to tyrosinase, an enzyme involved in the synthesis of melanin, forming a family of tyrosinase-related proteins. A genomic clone of human gp75 was used to map the human TYRP locus to chromosome 9, region 9p23, by nonradioactive fluorescent in situ hybridization. Specificity of hybridization was tested with a genomic fragment of human tyrosinase that mapped to a distinct site on 11q21. The 9p region has been reported to be nonrandomly altered in human melanoma, suggesting a role for the region near the TYRP locus in melanocyte transformation.     

Toxicity of extract of Magonia pubescens (Sapindales: Sapindaceae) St. Hil. to control the brown dog tick, Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae)

The action of crude ethanol extract of the stem bark of the soapberry Magonia pubescens St. Hil. was studied upon larvae of the Brown Dog tick Rhipicephalus sanguineus (Latreille). Tick larvae were obtained by maintaining gravid females in an incubator, after collecting them from naturally infested kennels. The tick larvae were placed in envelopes of filter paper impregnated with different concentrations of the extract dissolved in dimethylsulfoxide (DMSO) and distilled water. Four tests were repeated with each solution (n > 120). The control was carried out in DMSO and distilled water. The bioassays were performed at 27 +/- 1 degrees C, RH > 80% and 12:12 light cycle. Mortality was observed after 48 h exposure. All motionless larvae were considered to be dead. The extract of M. pubescens showed larvicidal potential against R. sanguineus. The lethal concentrations of 1503 ppm (LC50) and 9991 ppm (LC99) were obtained. There was no mortality in the control group. Based on the results of the current study, M. pubescens should be recognized as an future alternative acaricide for the control of Brown Dog tick. These results reinforce the importance of the preservation of this soapberry in its natural biome.     

Polysaccharides of algae: 60. Fucoidan from the Pacific brown alga Analipus japonicus (Harv.) Winne (Ectocarpales, Scytosiphonaceae)

A fucoidan containing L-fucose, sulfate, and O-acetyl groups at a molar ratio of 3 : 2 : 1, as well as minor amounts of xylose, galactose, and uronic acids was isolated from the brown alga Analipus japonicus collected in the Sea of Japan. The structures of the native polysaccharide and the products of its desulfation and deacetylation were studied by the methods of methylation, periodate oxidation, and NMR spectroscopy. It was shown that the polysaccharide molecule mainly consists of a linear carbohydrate chain of (1-->3)-linked alpha-L-fucopyranose residues, which bear numerous branches in the form of single alpha-L-fucopyranose residues (three branches at position 4 and one branch at position 2 per each ten residues of the main chain). Sulfate groups occupy positions 2 and (to a lesser extent) 4, most of the terminal nonreducing fucose residues being sulfated twice. The acetyl groups are located predominantly at positions 4. The structural role of minor monosaccharides was not established.