Targeted and untargeted metabolic profiling to discover bioactive compounds in seaweeds and hemp using gas and liquid chromatography-mass spectrometry

Greenhouse gas emissions are a global problem facing the dairy/beef industry. Novel feed additives consisting of seaweeds and hemp containing bioactive compounds are theorized to reduce enteric methane emissions. In this study we aimed to investigate the metabolic profiles of brown, red and green seaweeds and hemp using gas chromatography and liquid chromatography mass spectrometry. We used targeted and untargeted approaches, quantifying known halomethanes and phenolics, as well as identifying potentially novel bioactive compounds with anti-methanogenic properties. The main findings were: (a) Asparagopsis taxiformis contained halomethanes, with high concentrations of bromoform (4200 µg/g DW), six volatile halocarbons were tentatively identified; (b) no halomethanes were detected in the other studied seaweeds nor in hemp; (c) high concentrations of lignans were measured in hemp; (d) a high numbers of sulfated phenolic acids and unidentified sulfuric acid-containing compounds were detected in all seaweeds; (e) flavonoid glucosides and glucuronides were mainly identified in hemp; and (f) the condensed tannin gallocatechin was tentatively identified in Fucus sp. Using the combined metabolomics approach, an overview and in-depth information on secondary metabolites were provided. Halomethanes of Asparagopsis sp. have already been shown to be anti-methanogenic; however, metabolic profiles of seaweeds such as Dictyota and Sargassum have also been shown to contain compounds that may have anti-methanogenic potential

Upscaling cultivation of Saccharina latissima on net or line systems; comparing biomass yields and nutrient extraction potentials

Production of sugar kelp, Saccharina latissima, has the potential of extracting nutrients and carbon from the seawater and returning it to land as a bioresource. The production thereby acts as an emission capture and utilization instrument contributing to mitigation of eutrophication and climate change. To achieve higher biomass yields improving the effects on climate and environment, and the economic feasibility of the production, cultivation techniques need to be optimized. In Denmark so far, S. latissima production yields have been lower than yields documented from Norway and the Faroe Islands. Use of alternative cultivation infrastructure designs with a higher line density per area, and better understanding the effects of annual and seasonal variations in abiotic parameters on growth, could lead the way towards a future higher yield of the S. latissima production. In this study, S. latissima was cultivated in a Danish commercial scale cultivation site for two consecutive seasons comparing the yields of different cultivation techniques: cultivation on nets and a multi-layer single line system, while also testing the possibility of coppicing the blades instead of applying a full harvest. Biomass yields of 5.0 - 6.8 kg FW m-1 cultivation line year-1, and 10.9 – 30.4 kg FW m-2 net structure were achieved. Biomass production, nutrient and carbon extraction potentials up to 91.3 t FW, 110 kg N, 13.1 kg P and 5.1 t C ha-1 were obtained using net cultivation systems and a 1.5 years growth period. Depth of cultivation had a significant effect on yield, but no effect on dry matter, C, N or P contents of S. latissima in a multi-layered line system. Biomass yields from the same system and site varied with a factor of four between years. The use of coppicing enabled multiple harvests of S. latissima, providing however biomass of reduced quality in the second year. This study demonstrates that the production yield of S. latissima can be increased by optimizing cultivation infrastructure, and indicates that net systems, or other cultivation systems with a high line density in the upper water column, can be a means to increase the areal yield of S. latissima

Valuable biomolecules from nine North Atlantic red macroalgae:Amino acids, fatty acids, carotenoids, minerals and metals

In modern society, novel marine resources are scrutinized pursuing compounds of use in the medical, pharmaceutical, biotech, food or feed industry. Few of the numerous marine macroalgae are currently exploited. In this study, the contents of nutritional compounds from nine common North Atlantic red macroalgae were compared: the lipid content was low and constant among the species, whereas the fatty acid profiles indicated that these species constitute interesting sources of polyunsaturated fatty acids (PUFA). The dominating essential and non-essential amino acids were lysine and leucine, aspartic acid, glutamic acid, and arginine, respectively. The amino acid score of the nine algae varied from 44% to 92%, the most commonly first limiting amino acid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception of phosphorus, were higher than those described for conventional food. Low sodium/potassium ratios (0.08 - 2.54) suggested a potential for using the ash fraction for sodium salt replacement. The algae constituted rich sources of carbohydrates (40% to 71% of DM) which show their potential for a broader commercial exploitation. In some species, the concentrations of arsenic, cadmium, and lead exceeded limit values for application in food or feed. In conclusion, the nine algae represent promising potential sources of health promoting additives for human and animal diets, in whole or in a biorefinery concept

Negative emission potentials using biogenic building materials:a case study from Denmark

Significant reductions in carbon footprint can be achieved by increasing the use of biogenic materials in construction. In biogenic materials, carbon is embedded as long as the materials are not biologically degraded, and they consequently act as carbon reservoirs that keep CO2 out of the atmosphere. The reservoirs of carbon are maintained if the biogenic materials during maintenance and renovation are replaced by similar ones. Buildings containing more wood, straw, and other biogenic materials and less concrete, steel, and mineral wool are therefore part of the way forward for a sustainable restructuring of the construction industry. Until now, the main focus has been on reducing energy consumption of buildings, while less focus has been on energy consumption and the climate impact from the production of materials and the construction process itself. This paper examines the potential carbon reservoir in the building stock in Denmark for the next 100 years. In detail the paper describes potential building components made from biogenic resources, outlines the necessary amounts and qualities of biogenic materials, and summarizes the available biogenic resources. The article is based on the conditions for construction in Denmark and the opportunities Denmark has as an industrialized agricultural country with a long coastline, which can be utilized in the production of biogenic resources for manufacturing of building materials.Significant reductions in carbon footprint can be achieved by increasing the use of biogenic materials in construction. In biogenic materials, carbon is embedded as long as the materials are not biologically degraded, and they consequently act as carbon reservoirs that keep CO2 out of the atmosphere. The reservoirs of carbon are maintained if the biogenic materials during maintenance and renovation are replaced by similar ones. Buildings containing more wood, straw, and other biogenic materials and less concrete, steel, and mineral wool are therefore part of the way forward for a sustainable restructuring of the construction industry. Until now, the main focus has been on reducing energy consumption of buildings, while less focus has been on energy consumption and the climate impact from the production of materials and the construction process itself. This paper examines the potential carbon reservoir in the building stock in Denmark for the next 100 years. In detail the paper describes potential building components made from biogenic resources, outlines the necessary amounts and qualities of biogenic materials, and summarizes the available biogenic resources. The article is based on the conditions for construction in Denmark and the opportunities Denmark has as an industrialized agricultural country with a long coastline, which can be utilized in the production of biogenic resources for manufacturing of building materials

An objective framework to test the quality of candidate indicators of good environmental status

Large efforts are on-going within the EU to prepare the Marine Strategy Framework Directive's (MSFD) assessment of the environmental status of the European seas. This assessment will only be as good as the indicators chosen to monitor the 11 descriptors of good environmental status (GEnS). An objective and transparent framework to determine whether chosen indicators actually support the aims of this policy is, however, not yet in place. Such frameworks are needed to ensure that the limited resources available to this assessment optimize the likelihood of achieving GEnS within collaborating states. Here, we developed a hypothesis-based protocol to evaluate whether candidate indicators meet quality criteria explicit to the MSFD, which the assessment community aspires to. Eight quality criteria are distilled from existing initiatives, and a testing and scoring protocol for each of them is presented. We exemplify its application in three worked examples, covering indicators for three GEnS descriptors (1, 5, and 6), various habitat components (seaweeds, seagrasses, benthic macrofauna, and plankton), and assessment regions (Danish, Lithuanian, and UK waters). We argue that this framework provides a necessary, transparent and standardized structure to support the comparison of candidate indicators, and the decision-making process leading to indicator selection. Its application could help identify potential limitations in currently available candidate metrics and, in such cases, help focus the development of more adequate indicators. Use of such standardized approaches will facilitate the sharing of knowledge gained across the MSFD parties despite context-specificity across assessment regions, and support the evidence-based management of European seas

Crude fucoidan content in two North Atlantic kelp species, Saccharina latissima and Laminaria digitata - seasonal variation and impact of environmental factors

Fucoidans are sulphated fucose-rich polysaccharides predominantly found in the cell walls of brown algae. The bioactive properties of fucoidans attract increasing interest from the medico-pharmaceutical industries and may drive an increase in demand of brown algae biomass. In nature, the biochemical composition of brown algae displays a seasonal fluctuation driven by environmental factors and endogenous rhythms. To cultivate and harvest kelps with high yields of fucoidans, knowledge is needed on seasonal variation and impact of environmental conditions on the fucoidan content of brown algae. The relations between the fucoidan content and key environmental factors (irradiance, nutrient availability, salinity and exposure) were examined by sampling natural populations of the common North Atlantic kelps, Saccharina latissima and Laminaria digitata, over a full year at Hanstholm in the North Sea and Aarhus in the Kattegat. In addition, laboratory experiments were carried out isolating the effects of the single factors. The results demonstrated that (1) seasonal variation alters the fucoidan content by a factor of 2–2.6; (2) interspecific differences exist in the concentrations of crude fucoidan (% of dry matter): L. digitata (11%) > S. latissima (6%); and (3) the effects of single environmental factors were not consistent between species or between different conspecific populations. The ambiguous response to single environmental factors complicates prospective directions for manipulating an increased content of fucoidan in a cultivation scenario and emphasizes the need for knowledge on performance of local kelp ecotypes.This study was carried out as part of the MacroAlgae Biorefinery (MAB3), the MacroAlgae Biorefinery 4 (MAB4) and the Macrofuels projects, funded by The Danish Council for Strategic Research, the Innovation Fund Denmark and the European Union's Horizon 2020 research and innovation programme under grant agreement no. 654010, respectively