Given the current interest to reach sustainable protein supplies, seaweed proteins represent a potential source for pharmaceutical, nutraceutical, cosmeceutical, or food and feed applications. Some species are reported to contain high quantities of protein with original amino acid composition, which has been comparable to the values re- ported for other plant-based proteins. Further, seaweeds are rich in several sorts of valu- able proteins, such as peptides, enzymes, phycobiliproteins, glycoproteins, cell wall- attached proteins and mycosporine-like amino acids. However, some challenges remain to be addressed concerning protein yield. The extractability is affected by the presence of the tough polysaccharide-rich cell wall and the occurrence of phenolic compounds. In addition, because the protein content depends on species, harvesting season, location, and growing conditions, aquaculture systems are proposed as an alternative to scaling up seaweed biomass and increasing protein production. An up- date to the current knowledge of the seaweed protein extraction is addressed over the conventional procedures, which have been improved using assisted and alternative methods, including enzymatic (EAE), microwave (MAE), ultrasound (UAE), pulsed elec- tric fields (PEF), accelerated solvent extraction (ASE) and membrane filtration. The iden- tification and characterization of protein could be done through electrophoresis, chromatography or spectrometry. The potential bioactivities such as antioxidant, anti- viral, anti-inflammatory, or anticancer from seaweed-driven proteins, including novel glycoproteins and lectins, are discussed.
Digital library
-
-
Thallus erect or prostrate (decumbent), branched subdichotomously, laterally, secondly, radially or irregularly; axes and branches terete to flattened. Attached to solid substratum by a small discoid holdfast or living on sandy bottoms with part of the thallus immersed in the sand. Sometimes loose lying or floating in calm waters. Uniaxial construction but appearing multiaxial, pseudoparenchymatous with a small celled medulla.
Life history triphasic with isomorphic gametophytes and tetrasporapytes. In the genus Gracilaria, cystocarps exhibit traversing nutritive cells between the carposporophyte and the pericarp and spermataagia are in pits or conceptacles. In the genus Gracilariopsis, cystocarps lack the traversing nutritive cells and spermatangia are superficial. -
The Brunei–Indonesia–Malaysia–Philippines East Asia Growth Area (BIMP-EAGA) is located within the Coral Triangle, known to have the world’s richest biodiversity in marine flora and fauna. This region lies within the 10° N and 10° S of the Equator where natural populations of both Kappaphycus and Eucheuma grow luxuriantly and abundantly. It is in this same region where commercial cultivation of Kappaphycus and Eucheuma began in the Philippines around the mid-1960s. Commercial farming of Kappaphycus (which was originally called Eucheuma) was successful in the Philippines from the early 1970s, after which the technology was transferred to Indonesia and Malaysia in the late 1970s. No seaweed cultivation has been reported in Brunei. At present, carrageenophytes are cultivated in sub-tropical to tropical countries circumferentially around the globe within the 10° N and S of the Equator. However, their combined production is still low as compared to Indonesia, the Philippines, and Malaysia. Notably, few improvements in farming techniques have been made since its first introduction. Some of the major improvements were the introduction of deep-water farming using hanging long lines, multiple rafts, and spider webs in the Philippines; the use of short and long ‘loops’, instead of plastic ‘tie-tie’ in Indonesia; and mechanization in harvesting and use of solar “greenhouse” drying in Malaysia. Commercial cultivation of tropical red seaweeds in the BIMP-EAGA region is dominated by Kappaphycus and Eucheuma (carrageenophytes) and Gracilaria (agarophytes) and the area became the major region for the production of carageenophytes and agarophytes globally. In particular, Indonesia is a major center for the production of Gracilaria. There is an increasing demand for other agarophytes/carrageenophytes in the international market such as Gelidium spp., Pterocladia spp., Porphyroglossum sp., and Ptilophora sp. for paper and ethanol production in Indonesia and Malaysia, and Halymenia for phycoerythrin pigments in the Philippines currently pursued in an experimental stage. A summary of the present status, problems, sustainability, and challenges for the cultivation of tropical red seaweeds in the BIMP-EAGA region are discussed in this paper.
-
This work evaluated the use of effluent from a marine shrimp biofloc rearing system to cultivate the green seaweed Ulva. First, the growth of two Ulva species, U. ohnoi and U. fasciata, was evaluated. Second, the best-performing species was cultivated under two different stocking densities (2 g L-1 and 4 g L-1) to evaluate both growth and nutrient uptake rates, considering total ammonia nitrogen, nitrate, and orthophosphate. In both cases, environmental variables were monitored, and the cultivation medium, consisting of 25% biofloc water and 75% seawater, was exchanged weekly. U. ohnoi grew significantly better, considering all variables evaluated (p<0.05). The smaller stocking density produced a higher specific growth rate (p<0.05). Yield, however, was unaffected (p≥0.05). No significant differences in the nutrient uptake rates were observed (p≥0.05). Overall, this work highlights the importance of species selection for seaweed destined for aquaculture. Additionally, it also optimizes the cultivation of seaweeds, specifically U. ohnoi, using effluent from biofloc systems.
-
Water shortage is one of the leading global problems along with the depletion of energy resources and environmental deterioration. Recent industrialization, global mobility, and increasing population have adversely affected the freshwater resources. The wastewater sources are categorized as domestic, agricul- tural and industrial effluents and their disposal into water bodies poses a harmful impact on human and animal health due to the presence of higher amounts of nitrogen, phosphorus, sulfur, heavy metals and other organic/inorganic pollutants. Several conventional treatment methods have been employed, but none of those can be termed as a universal method due to their high cost, less efficiency, and non- environment friendly nature. Alternatively, wastewater treatment using microalgae (phycoremediation) offers several advantages over chemical-based treatment methods. Microalgae cultivation using wastew- ater offers the highest atmospheric carbon fixation rate (1.83 kg CO2/kg of biomass) and fastest biomass productivity (40–50% higher than terrestrial crops) among all terrestrial bio-remediators with concomi- tant pollutant removal (80–100%). Moreover, the algal biomass may contain high-value metabolites including omega-3-fatty acids, pigments, amino acids, and high sugar content. Hence, after extraction of high-value compounds, residual biomass can be either directly converted to energy through thermo- chemical transformation or can be used to produce biofuels through biological fermentation or transes- terification. This review highlights the recent advances in microalgal biotechnology to establish a biorefinery approach to treat wastewater. The articulation of wastewater treatment facilities with microalgal biorefinery, the use of microalgal consortia, the possible merits, and demerits of phycoreme- diation are also discussed. The impact of wastewater-derived nutrient stress and its exploitation to mod- ify the algal metabolite content in view of future concerns of cost-benefit ratios of algal biorefineries is also highlighted.
-
Cultivated kelps and other macroalgae have great potential in future provision of food, feed, bioenergy, fertilizer, and raw material for a range of chemical products including pharmaceuticals, food and feed additives, and cosmetics. Only a few species are currently cultivated, almost exclusively in Asia. There is a range of species that could be utilized in different parts of the world, providing that protocols for reproduction, propagation, and cultivation are developed. Domestication of species involves selection of traits that are desirable in cultivation and in the utilization of the harvested biomass. Genetic improvement of cultivated species through recombination of alleles and selection (breeding) has ensured high productivity and product quality in both agri- and aquaculture and will likely do so for macroalgae cultivation and use as well. According to the published literature, genetic improvement of kelps in Asia has so far largely relied on utilization of heterosis expressed in certain combinations of parental material, sometimes species hybrids. Here, we explore and evaluate the various methods that could be used in kelp breeding and propose an initial simple and low-cost breeding strategy based on recurrent mixed hybridization and phenotypic selection within local populations. We also discuss the genetic diversity in wild populations, and how this diversity can be protected against genetic pollution, either by breeding and cultivating local populations, or by developing cultivars that are not able to establish in, or hybridize with, wild populations.
-
A PDF on "CPI - Assets and Activities Relating to Seaweed".
-
Kelp forests and Sargassum beds not only are commercially important in themselves but also play an important role in spawning, breeding and feeding grounds for many kind of fish, shellfish, lobster and other important fisheries resources (Komatsu et al. 1982; Komatsu 1985; Ohno et al. 1990; Watanuki and Yamamoto 1990; Terawaki et al. 1998). The distributions of kelp forests comprising of the Ecklonia and Eisenia species are restricted to warm-water regions. A number of ecological studies on these plants have been undertaken with particular attention focused the re-establishment of kelp forests. This is due to declining populations that are a result of various factors, including human activities (Tsutsui et al. 1996). Thus, there has been development of construction techniques of artificial foundation, for kelp forests, and transplanting techniques of seed and adult marine algae, on artificial foundations (Hasegawa et al. 1995). Techniques of formation for seaweed bed may fall under either of the following classifications: 1. Spore dispersal technique; 2. The spore bag technique; 3. Ropeseeding technique; 4. Adult-plant transplantation method; 5. Concrete blocks; 6. The threading technique; 7. Gravel-bag technique; and 8. Transplantation of young plants (Largo and Ohno 1993). In this study, we used the spore bag on the roof of an artificial iron reef and a natural rock for a seaweed bed. The present paper describes the formation of seaweed beds by the spore bag method on an artificial iron reef and a natural rock (habitat).
-
The composition and the patterns of spatial and temporal variability of the epiphytic assemblages of Fucus vesiculosus of Clare Island, on the western coast of Ireland, were investigated for an annual cycle. Specimens of Fucus were collected on seven sampling dates from three sites of the island (Portlea, Kinnacorra and Portnakilly). Data of cover of the most common epiphytic species were collected and analysed by multivariate and univariate techniques. Elachista fucicola, Polysiphonia lanosa, Porphyra umbilicalis, Spongonema tomentosum and Ulva compressa were the most common species. Spatial and temporal variation was detected both for the whole assemblage and for the most abundant species. In general, the assemblage was quantitatively more abundant and diverse in spring–summer than in autumn–winter. In spring–summer, there was a clear differentiation among the assemblage of Portnakilly and the assemblages of the other two sites. Individual species were also generally more abundant in spring – summer and their distribution at the three sites was often not consistent in time; P. lanosa was the only epiphyte for which a consistent effect of site was found. Spatial variation on a scale of meters to tens of meters was the most striking pattern of distribution of the epiphytic assemblage; significant effects related to this spatial scale were detected both for the whole assemblage and for individual species. Phenological patterns of the epiphytic species determining availability of propagules and limited dispersal, leading to aggregated patterns of distribution, are considered the main factors responsible of such patchiness. The importance of the incorporation of small spatial scales in sampling designs analysing the distributional patterns of epiphytic assemblages is discussed.
-
Background
Porphyra yezoensis Ueda is one of the most important edible seaweed, with a dimorphic life cycle which consists of gametophyte as macroscopical blade and sporophyte as microscopic filamentous. Conspicuous differences exist in the two generations, such as morphology, cell structure, biochemistry, physiology, and so on. The developmental process of Porphyra yezoensis has been studied thoroughly, but the mechanism is still ambiguous and few studies on genetic expression have been carried out.
In this study, the suppression subtractive hybridization (SSH) method conducted to generate large-scale expressed sequence tags (EST) is designed to identify gene candidates related to the morphological and physiological differences between the gametophytic and sporophytic generations of Porphyra yezoensis Ueda.
Findings
Each 300 clones of sporophyte and gametophyte cells were dipped onto the membrane for hybridization. The result of dot-blot suggested there were 222 positive clones in gametophyte library and 236 positive clones in sporophyte library. 383 positive clones of strongest signals had been sequenced, and 191 EST sequences of gametophyte and 192 of sporophyte were obtained.
A total of 196 genes were obtained, within which 104 genes were identified from the gametophyte and 92 from the sporophyte. Thirty-nine genes of the gametophyte and 62 genes of the sporophyte showed sequence similarity to those genes with known or putative functions which were classified according to their putative biological roles and molecular functions. The GO annotation showed about 58% of the cellular component of sporophyte and gametophyte cells were mainly located in cytoplasm and nucleus. The special genes were located in Golgi apparatus, and high expression in plastid, ribosome and endoplasmic reticulum. The main biological functions of gametophyte cells contributed to DNA repair/replication, carbohydrate metabolism, transport and transcription, especially in response to heat and oxidative stress. The sporophyte cell expresses more genes in transcription, transport, carbohydrate metabolism, particularly in signal transduction, DNA and protein modification, protein and nucleotide metabolism. Four genes are expressed on both gametophyte and sporophyte cells and eighteen genes have not been annotated.
Conclusion
According to the information of GO annotation, the gametophyte tends to growth and self- protection while the sporophyte tends to be more active in development. Interpretation of the differentially expressed genes revealed new insights into the molecular processes of the generation alternation of Porphyra yezoensis. Further investigation are needed due to insufficiency of functional genes research and indeterminancy of the functions of many sequences.
Pages
Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
Funding for this web portal is provided by the World Wildlife Fund and the University of Hawaii-Hilo.