Seaweed Energy Solutions (Norway)

Two commercially utilized kelp species, winged kelp (Alaria esculenta) and sugar kelp (Saccharina latissima), can accumulate high amounts of iodine and thereby pose a health concern if consumed in excess. Water blanching is used industrially to reduce the iodine content. This study aimed to optimize the blanching conditions to reduce the energy consumption and environmental impact by investigating the parameters of temperature, duration, use of sea or fresh water, biomass-to-water ratio, and recycling of water. The study investigated the impact of the blanching conditions on composition of the biomass, including nutrient content and potential toxic elements. The iodine content was reduced to 5% of the initial content for S. latissima and to 8% for A. esculenta at the optimal conditions in the present study, which was blanching in seawater at 80 °C for 2 min. Using tap water at the same conditions resulted in a reduction to 7 and 11% of the initial content. The content of arsenic in blanched winged kelp was reduced to levels below the maximum allowed content in feed, whereas the content in blanched sugar kelp remained above this level. This study provides a comprehensive set of data on blanching of the two kelp species, with high relevance for the industrial scale-up of kelp processing.

Metal oxide nanoparticles synthesized via green routes are increasingly recognized for their potential in water treatment applications due to their enhanced photocatalytic properties. This study presents a novel approach for the synthesis of zinc oxide nanoparticles (ZnO NPs) using κ-carrageenan derived from alkali-treated Kappaphycus striatus (Katunay itum) as a capping agent during ZnO NP formation and as a source of nonmetal dopants, carbon, and sulfur. The resulting carrageenan-mediated ZnO NPs (car-ZnO NPs) were thoroughly characterized using physicochemical techniques to evaluate their morphological, optical, and chemical properties. The findings revealed that κ-carrageenan incorporation significantly reduced the band gaps and crystallite sizes of ZnO NPs. Specifically, the 0.75 car-ZnO NPs exhibited the most uniform particle size distribution and demonstrated superior photocatalytic efficiency in degrading methylene blue (MB), methyl orange (MO), and hexavalent chromium (Cr(VI)) under UV light, outperforming unmodified ZnO NPs (0.00 car-ZnO). The enhanced photocatalytic activity is attributed to the narrowed band gap and effective doping with carbon and sulfur, which improved charge carrier separation and extended their lifetime. Additionally, car-ZnO NPs showed excellent photostability and high efficiency in repeated photocatalytic cycles, emphasizing their eco-friendly nature and practicality for water treatment. This study highlights the dual role of κ-carrageenan as a promising, sustainable material for synthesizing ZnO NPs with advanced photocatalytic properties, offering a green alternative for effective wastewater treatment and environmental remediation.

Plastic pollution is an environmental emergency and finding sustainable alternatives to traditional plastics has become a pressing need. Seaweed-based bioplastic has emerged as a promising solution, as it is biodegradable and made from renewable biomass, while seaweed cultivation itself provides various environmental benefits. However, the feasibility of implementing a brown seaweed-based bioplastic supply chain in a realistic setting remains unclear, as previous research focused either on single processing steps or on virtual supply chains aggregating data from different studies. This study describes a case study for seaweed-based bioplastic within the PlastiSea research project: from seaweed cultivation to biomass processing and bioplastic and composite material development at the lab and pilot scale, thus providing insights into its feasibility. Adopting a multidisciplinary approach, the study employs multiple methods to characterize each stage in the supply chain and provides an overall life cycle assessment (LCA) as well as lessons learned throughout the process. The analysis showed potential for producing and utilizing multiple co-products from the same seaweed source, including biopolymer extracts with varying degrees of refinement for use in low-cost (bioplastic films) and high-cost (microfiber composites) applications. The use of residual biomass as a source of alginates for producing bioplastics offers a low-cost and sustainable biomass supply currently not competing with other markets. The LCA results indicate the potential for reducing the environmental impact of seaweed-based bioplastic production through upscaling and increasing process efficiency.

BackgroundThe sugar kelp Saccharina latissima is a Laminariales species widely distributed in the Northern Hemisphere. Its physiology and ecology have been studied since the 1960s, given its ecological relevance on western temperate coasts. However, research interest has been rising recently, driven mainly by reports of negative impacts of anthropogenically induced environmental change and by the increased commercial interest in cultivating the species, with several industrial applications for the resulting biomass.ScopeWe used a variety of sources published between 2009 to May 2023 (but including some earlier literature where required), to provide a comprehensive review of the ecology, physiology, biochemical and molecular biology of S. latissima. In so doing we aimed to better understand the species’ response to stressors in natural communities, but also inform the sustainable cultivation of the species.ConclusionDue to its wide distribution, S. latissima has developed a variety of physiological and biochemical mechanisms to adjust to environmental changes, including adjustments in photosynthetic parameters, modulation of osmolytes and antioxidants, reprogramming of gene expression and epigenetic modifications, among others summarized in this review. This is particularly important because massive changes in the abundance and distribution of S. latissima have already been observed. Namely, presence and abundance of S. latissima has significantly decreased at the rear edges on both sides of the Atlantic, and increased in abundance at the polar regions. These changes were mainly caused by climate change and will therefore be increasingly evident in the future. Recent developments in genomics, transcriptomics and epigenomics have clarified the existence of genetic differentiation along its distributional range with implications in the fitness at some locations. The complex biotic and abiotic interactions unraveled here demonstrated the cascading effects the disappearance of a kelp forest can have in a marine ecosystem. We show how S. latissima is an excellent model to study acclimation and adaptation to environmental variability and how to predict future distribution and persistence under climate change.

Enterococcus faecalis (E. faecalis) biofilm-associated persistent endodontic infections (PEIs) are one of the most common tooth lesions, causing chronic periapical periodontitis, root resorption, and even tooth loss. Clinical root canal disinfectants have the risk of damaging soft tissues (e.g., mucosa and tongue) and teeth in the oral cavity, unsatisfactory to the therapy of PEIs. Nanomaterials with remarkable antibacterial properties and good biocompatibility have been developed as a promising strategy for removing pathogenic bacteria and related biofilm. Herein, carbon dots (CDs) derived from fucoidan (FD) are prepared through a one-pot hydrothermal method for the treatment of PEIs. The prepared FDCDs (7.15 nm) with sulfate groups and fluorescence property are well dispersed and stable in water. Further, it is found that in vitro FDCDs display excellent inhibiting effects on E. faecalis and its biofilm by inducing the formation of intracellular and extracellular reactive oxygen species and altering bacterial permeability. Importantly, the FDCDs penetrated the root canals and dentinal tubules, removing located E. faecalis biofilm. Moreover, the cellular assays show that the developed FDCDs have satisfactory cytocompatibility and promote macrophage recruitment. Thus, the developed FDCDs hold great potential for the management of PEIs.Graphical

Increasing global demand for food has generated a need for new strategies to feed a fast-growing population. Oceans appear as a sustainable solution, providing alternative sources of food such as macroalgae. These sea vegetables have high nutritional value and provide functional and health benefits. The sugar kelp Saccharina latissima is an emerging edible seaweed used mainly for human consumption. Although much is known about its biochemical compositions its lipidome remains unexplored. The aim of the present study was to characterize the polar lipid profile of S. latissima using a lipidomic-mass spectrometry HILIC-LC-MS based analysis. This approach allowed the identification of 197 molecular species of polar lipids, including glycolipids, phospholipids and betaine lipids. Several molecular species identified are carriers of polyunsaturated fatty acids with nutritional value and have been reported with anti-inflammatory, anti-microbial and anti-proliferative activity. Saccharina latissima is an emerging candidate to promote blue biotechnology inspired by the ocean.

In South Africa, Porphyra has, until recently, been little exploited, having been harvested only for a small healthfood market. However, the advent of land-based abalone farming has increased the pressure on wild Porphyra populations, as Porphyra is in demand for abalone fodder. This paper reports on the effects of a simulated harvest on Porphyra populations and those of sympatric fauna. Harvesting, starting in autumn, was found to reduce the biomass of Porphyra, an effect detectable up to six months later. Porphyra had a patchy distribution, with patches having a mode of approximately 300 thalli m−2. The main effect of harvesting was the removal of patches, as mean thallus size changed little in response to harvesting. Nine months after the start of the experiment, control populations had been reduced, through loss of patches, to the level of treatment populations. Although harvesting Porphyra reduced populations of some sympatric fauna (amphipods, isopods and littorinid snails), natural Porphyra population decreases had a comparable effect. Some recommendations are discussed for the management and controlled harvesting of Porphyra populations in South Africa.