Composting of seaweed waste: Evaluation on the growth of Sarcocornia perennis

Biochar, phosphate, and magnesium oxide in seaweed and cornstarch dregs co-composting: Enhancing organic matter degradation, humification, and nitrogen retention

Seaweed waste, abundant and rich in plant-stimulating properties, has the potential to be transformed into valuable soil amendments through proper composting and utilization management. Given its low carbon-to-nitrogen ratio, co-composting seaweed with carbon-rich cornstarch dregs is an effective strategy. However, the potential application of co-composting largely depends on the efficiency of the composting and the quality of the product. This study explores the effects of adding 10 % corn stalk biochar to a co-composting system of seaweed and cornstarch dregs, alongside varying buffering capacities of phosphates (KH2PO4 and K2HPO4·3H2O-KH2PO4) and MgO, on the degradation efficiency of organic matter, nitrogen transformation, and humification. The results indicate that the addition of biochar and salts enhances the oxygen utilization rate (OUR) and cellulase activity during the thermophilic phase. Additionally, X-ray diffraction (XRD) and parallel factor analysis (PARAFAC) demonstrate more intense solubilization and transformation of proteinaceous substances, along with cellulose degradation. These processes are crucial for enhancing organic matter degradation and humification, significantly boosting degradation (with an increase of 28.6 % to 33.8 %) and humification levels (HA/FA increased by 37.1 % to 49.6 %). Specifically, groups with high buffering capacity significantly promote the formation of NO3--N and NH4+-N, and a higher degree of humification, creating an optimal environment for significantly improving nitrogen retention (increased by 4.80 %). Additionally, this treatment retains and slightly enhances the plant-stimulating properties of seaweed. These findings underscore the potential of integrating biochar with specific ratios of phosphates and MgO to enhance composting efficiency and product quality while preserving the plant-stimulating effects of seaweed.

Low temperature-resistant superhydrophobic and elastic cellulose aerogels derived from seaweed solid waste as efficient oil traps for oil/water separation

Aerogel has excellent application potential in adsorption, heat preservation, and other areas due to its typical advantages of low density and high porosity. However, there are several issues with the use of aerogel in oil/water separation, including weak mechanical qualities and challenges in eliminating organic contaminants at low temperature. Inspired by cellulose Iα, which has excellent performance at low temperature, this study used cellulose Iα nanofibers extracted from seaweed solid waste as the skeleton, through covalent cross-linked with ethylene imine polymer (PEI) and hydrophobic modification of 1, 4-phenyl diisocyanate (MDI), supplemented by freeze-drying technology to form three-dimensional sheet, and successfully obtained cellulose aerogels derived from seaweed solid waste (SWCA). The compression test shows that the maximum compressive stress of SWCA is 61 kPa, and the initial performance still maintains 82% after 40 cryogenic compression cycles. In addition, the contact angles of water and oil on the surface of the SWCA were 153° and 0°, respectively, and the stable hydrophobic time in simulated seawater is more than 3 h. By combining the elasticity and superhydrophobicity/superoleophilicity, the SWCA with an oil absorption capacity of up to 11-30 times its mass, might be utilized repeatedly for the separation of an oil/water mixture.

Potent Bioactive Compounds From Seaweed Waste to Combat Cancer Through Bioinformatics Investigation

The seaweed industries generate considerable amounts of waste that must be appropriately managed. This biomass from marine waste is a rich source of high-value bioactive compounds. Thus, this waste can be adequately utilized by recovering the compounds for therapeutic purposes. Histone deacetylases (HDACs) are key epigenetic regulators established as one of the most promising targets for cancer chemotherapy. In the present study, our objective is to find the HDAC 2 inhibitor. We performed top-down in silico methodologies to identify potential HDAC 2 inhibitors by screening compounds from edible seaweed waste. One hundred ninety-three (n = 193) compounds from edible seaweeds were initially screened and filtered with drug-likeness properties using SwissADME. After that, the filtered compounds were followed to further evaluate their binding potential with HDAC 2 protein by using Glide high throughput virtual screening (HTVS), standard precision (SP), extra precision (XP), and quantum polarized ligand docking (QPLD). One compound with higher negative binding energy was selected, and to validate the binding mode and stability of the complex, molecular dynamics (MD) simulations using Desmond were performed. The complex-binding free energy calculation was performed using molecular mechanics-generalized born surface area (MM-GBSA) calculation. Post-MD simulation analyses such as PCA, DCCM, and free energy landscape were also evaluated. The quantum mechanical and electronic properties of the potential bioactive compounds were assessed using the density functional theory (DFT) study. These findings support the use of marine resources like edible seaweed waste for cancer drug development by using its bioactive compounds. The obtained results encourage further in vitro and in vivo research. Our in silico findings show that the compound has a high binding affinity for the catalytic site of the HDAC 2 protein and has drug-likeness properties, and can be utilized in drug development against cancer.

Evolution of physicochemical properties and bacterial community in aerobic composting of swine manure based on a patent compost tray

The objective of this study was to explore the changes in physicochemical properties and bacterial community during swine manure composting with a new compost tray (CT). The results showed that the organic matter (OM), moisture content (MC), and C/N decreased. The total Kjeldahl nitrogen (TKN), P₂O₅, K₂O and humic acids (HAs) contents of the compost increased. The properties of the final compost product comply with the requirements of regulation except for the moisture according to NY/T 525-2012. Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes were the major phyla during the composting. Genus Terrisporobacter played a key role in degrading organic (OM). The content of K₂O was main factors driving the succession of bacterial communities. These findings shed some novel lights into the dynamic changes of physicochemical propertied and their impact on bacterial community in a composting process.

Optimization of liquid fertilizer production from waste seaweed: A design of experiment based statistical approach

In Istanbul, which is surrounded by the sea on 3 sides, thousands of tons of seaweed that have formed naturally every year are washed ashore. In this study, the usability of these seaweeds which are landfilling already in fertilizer production was discussed. Liquid fertilizer production was carried out using 3 different physical and 4 different biological methods, and the produced fertilizers were diluted in 5 different ratios (1%, 10%, 25%, 50%, and 100%) and applied to cress seed. The effect of each fertilizer and its concentration on seed germination, plant length, number of leaves, and soil moisture-holding capacity was studied. The data obtained were analyzed using Response Surface Methodology (RSM). The results showed that if seaweed was fermented with anaerobic seed sludge for 15 days and applied to the plant by diluting it to 15-25%, plant growth will be supported at an optimum level. It has also been shown that if the seaweed was fermented with yeast culture for 18 days and fed with a concentration of >90%, the moisture-holding capacity of the soil could be increased by up to 27%.

A Review on Sarcocornia Species: Ethnopharmacology, Nutritional Properties, Phytochemistry, Biological Activities and Propagation

Sarcocornia A. J. Scott is a halophytic edible succulent plant belonging to the Amaranthaceae family. To date, the genus includes 28 species distributed worldwide in saline environments, usually salt marshes. Sarcocornia (Scott) is similar to Salicornia (L.), which has a recognized commercial value in morphological and taxonomical traits. Species of both genera are commonly named samphire or glassworts in Europe, and their fleshy shoots are commercialized under their traditional names. Due to their nutritional, organoleptic and medicinal properties, Sarcocornia species have a high economic potential in various biotechnology sectors. Being highly tolerant to salt, they can be cultivated in saline conditions, and dissimilar to Salicornia, they are perennial, i.e., they can be harvested year-round. Therefore, Sarcocornia species are considered promising gourmet vegetables to be explored in the context of climate change, soil and water salinization and eco-sustainability. We hereby put together and reviewed the most relevant information on Sarcocornia taxonomy, morphology, nutritional and pharmacological properties, uses in ethnomedicine, potential applications in biotechnology, and propagation strategies.

Advances in Extraction Methods to Recover Added-Value Compounds from Seaweeds: Sustainability and Functionality

Seaweeds are a renewable natural source of valuable macro and micronutrients that have attracted the attention of the scientists in the last years. Their medicinal properties were already recognized in the ancient traditional Chinese medicine, but only recently there has been a considerable increase in the study of these organisms in attempts to demonstrate their health benefits. The extraction process and conditions to be used for the obtention of value-added compounds from seaweeds depends mainly on the desired final product. Thermochemical conversion of seaweeds, using high temperatures and solvents (including water), to obtain high-value products with more potential applications continues to be an industrial practice, frequently with adverse impact on the environment and products’ functionality. However more recently, alternative methods and approaches have been suggested, searching not only to improve the process performance, but also to be less harmful for the environment. A biorefinery approach display a valuable idea of solving economic and environmental drawbacks, enabling less residues production close to the much recommended zero waste system. The aim of this work is to report about the new developed methods of seaweeds extractions and the potential application of the components extracted.