Seven case studies are presented on commercial seaweed resources; five on wild crops, respectively Ascophyllum nodosum, Chondrus crispus, Gelidium, Laminaria longicruris and Macrocystis, are provided along with case studies of the farmed crops of Eucheuma and Laminaria japonica. Individually the cases range from descriptions of the wild crops and their management to the managed production of farmed crops including, in several examples, some information on economics and/or processing. These initial seven cases range from those emphaizing but one species from but one part of one country, to studies of a genus as it occurs commercially throughout the world.
Digital library
-
-
CARRAGEENAN IS A COMMON FOOD ADDITIVE extracted from red seaweed. For the past four decades, scientists have warned that the use of carrageenan in food is not safe. Animal studies and in-vitro studies with human cells have repeatedly shown that food-grade carrageenan* causes gastrointestinal inflammation and higher rates of intestinal lesions, ulcerations, and even malignant tumors. In fact, roughly 3,855 research papers show that carrageenan induces inflammation, most of which test the effectiveness of anti-inflammatory drugs. In the past decade, researchers have successfully identified several ways in which food-grade carrageenan causes harm. The chemical structure of carrageenan—unique chemical bondsnot found in other seaweeds or gums—affects the body in several ways. Most notably, it triggers an immune reaction, which leads to inflammation in the gastrointestinal system. Prolonged inflammation is a precursor to more serious diseases, including cancer.
-
Polysaccharides are underexploited marine bioresources and a source of natural ingredients for functional foods. Cardioprotective property of polysaccharides derived from marine algae possess good nutrient and medicinal benefits and could be used as an alternative source of dietary fibre. Bioactive sulphated polysaccharides are the main components of soluble fibre in marine algae, hence making it a valuable source. This review gives an overview of the cardioprotective properties of polysaccharides derived from marine algae. Recent studies have provided evidence that polysaccharides (chitin and fucoidan) from marine algae can play a vital role in cardioprotective activity. Further research work, especially clinical studies, are needed in order to gain a better knowledge of the structure–function relationship whereby these polysaccharides can exert potent cardioprotective activities at safe levels.
-
We want to warmly welcome all participants to the Symposium on Environmental Engineering (SEE), held in the scope of the 4th Doctoral Congress (DCE21) hosted at the Faculty of Engineering of the University of Porto (FEUP), Porto, Portugal, on the 28th and 29th of June 2021. This time, due to the COVID-19 pandemic, the event is entirely conducted in virtual mode. This Symposium is organized by PhD students of the Doctoral Program in Environmental Engineering (PDEA) at FEUP, with the support of the professors. The Environmental Engineering Symposium covers broad, important and multidisciplinary themes, with oral and poster presentations comprising a wide range of topics included in the UN Sustainable Development Goals: ▪ Clean Water: Emerging Pollutants, Monitoring and Treatment; ▪ Air Quality: Emissions, Assessment and Health Safety; ▪ Waste Management and Circular Economy; ▪ Energy, Sustainability and Innovation: Products, Technologies and Climate Change Mitigation. It is with great honour that we welcome the Keynote Speakers, who elevate the Symposium with their participation and by highlighting current hot topics of environmental engineering: ▪ Dr. Despo Fatta-Kassinos, a leading international scientist in water quality and management, Professor at the Department of Civil and Environmental Engineering and Director of Nireas-International Water Research Center of the University of Cyprus; ▪ Dr. Xavier Querol Carceller, a worldwide recognized scientist in air quality from the Institute of Environmental Assessment and Water Research (IDAEA) in Spain, who received several awards, among which the 2013 Award “Rey Jaime I” for the Protection of the Environment and the 2020 National Research Award “Alejandro Malaspina” on Natural Resources; ▪ Dr. Nuno Lacasta, the Executive Board President (CEO) of the Portuguese Environment Agency – APA. In addition, we thank the PDEA alumni at the round table session, which also provide a noteworthy contribution to the Symposium by emphasizing the role and importance of a PhD in Environmental Engineering. The Organizing Committee received over 65 communications, a new record. A total of 26 oral and 40 poster presentations of great quality were selected. We take this opportunity also to acknowledge all authors for their contributions, the Scientific Committee and the participant Institutions for their support. A final thank you to our Symposium’s sponsors: LEPABE, LSRE-LCM, CERENA and MIEA. Thank you all!! Porto, June 2021
-
Carbon offsetting—receiving credit for reducing, avoiding, or sequestering carbon—has become part of the portfolio of solutions to mitigate carbon emissions, and thus climate change, through policy and voluntary markets, primarily by land-based re- or afforestation and preservation [1, 2]. However, land is limiting, creating interest in a rapidly growing aquatic farming sector of seaweed aquaculture [3, 4, 5]. Synthesizing data from scientific literature, we assess the extent and cost of scaling seaweed aquaculture to provide sufficient CO2eq sequestration for several climate change mitigation scenarios, with a focus on the food sector—a major source of greenhouse gases [6]. Given known ecological constraints (nutrients and temperature), we found a substantial suitable area (ca. 48 million km2) for seaweed farming, which is largely unfarmed. Within its own industry, seaweed could create a carbon-neutral aquaculture sector with just 14% (mean = 25%) of current seaweed production (0.001% of suitable area). At a much larger scale, we find seaweed culturing extremely unlikely to offset global agriculture, in part due to production growth and cost constraints. Yet offsetting agriculture appears more feasible at a regional level, especially areas with strong climate policy, such as California (0.065% of suitable area). Importantly, seaweed farming can provide other benefits to coastlines affected by eutrophic, hypoxic, and/or acidic conditions [7, 8], creating opportunities for seaweed farming to act as “charismatic carbon” that serves multiple purposes. Seaweed offsetting is not the sole solution to climate change, but it provides an invaluable new tool for a more sustainable future.
-
The growing world population demands an in- crease in animal protein production. Seaweed may be a valu- able source of protein for animal feed. However, a biorefinery approach aimed at cascading valorisation of both protein and non-protein seaweed constituents is required to realise an eco- nomically feasible value chain. In this study, such a biorefinery approach is presented for the green seaweed Ulva lactuca containing 225 g protein (N × 4.6) kg−1 dry mat- ter (DM). The sugars in the biomass were solubilised by hot water treatment followed by enzymatic hydrolysis and centri- fugation resulting in a sugar-rich hydrolysate (38.8 g L−1 sugars) containing glucose, rhamnose and xylose, and a protein-enriched (343 g kg−1 in DM) extracted fraction. This extracted fraction was characterised for use in animal feed, as compared to U. lactuca biomass. Based on the content of essential amino acids and the in vitro N (85 %) and organic matter (90 %) digestibility, the extracted fraction seems a promising protein source in diets for monogastric animals with improved characteristics as compared to the intact U. lactuca. The gas production test indicated a moderate rumen fermentation of U. lactuca and the extracted frac- tion, about similar to that of alfalfa. Reduction of the high content of minerals and trace elements may be required to allow a high inclusion level of U. lactuca products in animal diets. The hydrolysate was used suc- cessfully for the production of acetone, butanol, ethanol and 1,2-propanediol by clostridial fermentation, and the rhamnose fermentation pattern was studied.
-
Seaweeds (also called macroalgae) are considered a potential biomass feedstock for biorefineries for production of energy and chemicals. In this study, a biorefinery strategy for the brown seaweed Saccharina latissima is described. Fresh S. latissima harvested at the Irish coast contained glucose and mannitol as most abundant fermentable sugars. The fresh biomass was chopped and pressed in order to obtain a liquid fraction (press juice), which contained 16 g/L of mannitol as main sugar component, and an insoluble fraction referred to a “press cake”. The mannitol in the press liquid has been extracted and purified to serve as a substrate for chemical conversions. The use of the press juice and hydrolysed press cake as substrates for production of acetone, butanol and ethanol by anaerobic fermentation has been evaluated. While the press juice was easily fermentable after addition of nutrients, the press cake was toxic for the microorganisms. When the press cake hydrolysate was diluted, fermentation was possible. The toxicity of the hydrolysate might be associated to the high salt concentrations determined in it. The use of the residue after enzymatic hydrolysis of the press cake as fertilizer has been evaluated.
-
The secondary metabolites of seaweed Ulva fasciata and Hypnea musciformis,collected form southeast and southwest coast of India. were tested for biotoxicity potential. Both species bowed potent activity in antibacterial, brine shrimp cytotoxicity, larvicidal, antifouling and ichthyotoxicity assays.
-
The brown seaweed Sargassum wightii Greville ex J. Agardh 1848 was collected from Pamban (south east coast of Tamilnadu, India; Latitude 9o18’N and Longitude 79o12’ E) and extracted with different solvents such as acetone, ethanol, benzene and chloroform in a soxhlet apparatus. The antibacterial activity of the extracts were tested against natural pathogens isolated from housefly (Musca domestica Linnaeus 1758), such as Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus, Micrococcus luteus, Pseudomonas aeruginosa and Escherichia coli respectively. The extracts were also subjected to alpha amylase inhibitory, anti-inflammatory and antioxidant activities following standard protocols. Ethanol extract exerted high inhibitory effect on all the microbes and was assertive against B. cereus (14.2 mm). Potential and significant (p<0.05) alpha amylase inhibition was observed in the chloroform extract (81.24±8.063%). The benzene extract had significantly (p<0.05) higher antioxidant activity (74.44±3.27%) and the antiinflammatory activity was comparatively higher in the acetone extract (65.5±1.21%). However, the control drugs exhibited better activity than all the tested extracts. The qualitative phytochemistry showed the presence of flavonoids, pholobatannins, phenolic compounds, aromatic acids and xanthoproteins. The Fourier transform infra-red (FT-IR) spectrum contained eight major peaks which confirmed the presence of amino, keto, fluoro alkane group and aromatic compounds in the extracts which could be responsible for the bioactivity.
-
This presentation by Klaus Lüning discusses ways to cultivate seaweed, the development of seaweed, and the pros/cons that come along with seaweed cultivation.
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.