Matís (Iceland)

Salmon farming has a low feed conversion ratio and provides high-quality protein with relatively low environmental input. In Iceland, production is currently 45,000 t annually and is projected to reach 245,000 t by 2033, over 30 % of which is expected from land-based systems. This study assessed the potential environmental impacts of land-based Atlantic salmon farming using Life Cycle Assessment (LCA), with a functional unit of 1 t of salmon produced in land-based farms in Iceland in 2021. A hypothetical scenario investigated the avoided environmental burdens of utilizing the salmon manure as fertilizer based solely on its nitrogen, phosphorus, and potassium content, instead of producing synthetic fertilizer. In addition, a sensitivity analysis tested four electricity mix scenarios: the default Ecoinvent Icelandic electricity mix (Scenario 0), an LCA-based Icelandic energy mix (Scenario 1), the residual mix accounting for Guarantees of Origin (GOs) certificates (Scenario 2), and the Ecoinvent European mix (Scenario 3). For Scenario 0, impacts per functional unit were: 1.4 t CO 2 eq (Global Warming Potential), 8 kg SO 2 eq (Terrestrial Acidification), 0.6 kg P eq (Freshwater Eutrophication), 582 m 2 a crop eq (Land Use), and 8659 m 3 world eq (Water Scarcity Footprint). These results reflect relatively low environmental burdens compared to similar studies in other countries, largely due to Iceland's renewable energy. However, results from scenario 3 in the sensitivity analysis led to a GWP increase by 377 %, due to its large fossil-based composition. These results stress the importance of energy sourcing in shaping environmental outcomes and can guide impact reduction strategies for future land-based salmon farming in Iceland. • Iceland land-based salmon shows lower environmental impacts than studies overseas. • Feed production is an environmental hotspot in land-based salmon farming in Iceland. • Using salmon manure as fertilizer may avoid certain impacts of synthetic production. • Transparent LCI data, including energy mix and GOs, improves impact accountability.

We presents the discovery and molecular characterization of a novel lytic enzyme from the extremophilic Thermus thermophilus MAT72 phage vB_Tt72. The protein of 346-aa (MW=39,705) functions as phage vB_Tt72 endolysin and shows low sequence identity (<37%) to members of M23 family of peptidoglycan hydrolases, except for two uncharacterized endopeptidases of T. thermophilus phages: φYS40 (87%) and φTMA (88%). The enzyme exhibits lytic activity mainly against bacteria of the genus Thermus and, to a lesser extent, against other Gram-negative and Gram-positive bacteria. The protein is monomeric in solution and is highly thermostable (Tm=98.3°C). It retains∼50% of its lytic activity after 90min of incubation at 99°C. Crystallographic analysis, at 2.2Å resolution, revealed a fold characteristic of M23 metallopeptidases, accounting for 40% of the structure. The remaining parts of the molecule are folded in a manner that was previously undescribed. The M23 fold contains a Zn2+ ion coordinated by a conserved His-Asp-His triad, and two conserved His residues essential for catalysis. The active site is occupied by a phosphate or a sulfate anion, while the substrate-binding groove contains a ligand, which is a fragment of E. coli peptidoglycan. The common sequence-based criteria failed to identify the protein as (hyper)thermophilic. It is likely that the protein's thermal stability is owed to peculiar features of its three-dimensional structure. Instead of trimmed surface loops, observed in many thermostable proteins, the catalytic domain contains two long loops that interlace and form an α-helical bundle with its own hydrophobic core.

There has been much recent research interest in the potential of macroalgae (seaweed) as a methane-suppressing feed supplement for ruminants, but there are numerous potential seaweed species available that have varying compositions of potentially beneficial or deleterious consequence. Therefore, the objective of the present study was to determine the effects of feeding 3 mixtures of 3 seaweeds at levels within EU regulatory limits for ration iodine concentration on methane production and milk yield and composition of dairy cows. Forty lactating (204 ± 5.6 DIM) Holstein cows were randomly assigned to 1 of 4 treatments (10 per treatment) in blocks based on DIM, parity, BW, and milk yield. Treatments were a control TMR and 3 seaweed mixtures replacing TMR grass silage: Ascophyllum nodosum, Fucus vesiculosus, and Asparagopsis taxiformis (AN, FV, and AT, respectively; 5:45:50 and 1.5 g/kg DM), AN and FV (AN:FV at 90:10 and 6.5 g/kg DM), or FV and AN (FV:AN at 90:10 and 17.5 g/kg DM). Cows were individually fed for ad libitum DMI in freestall housing and treatments continued for 7 wk, with daily measurements of milk yield and DMI and weekly measurements of milk composition. Methane emission was estimated using 2 GreenFeed head chambers in wk 5 to 7 of treatment, milk mineral concentrations were measured in wk 1 to 6, and milk FA composition was measured in wk 6. Feeding the AN:FV and FV:AN mixtures had no effect on methane emission (g/d) or yield (g/kg DMI), whereas cows fed AT (0.075% of DM) in combination with AN and FV tended to have a lower methane emission (9%) and methane yield (12%) than cows fed the control diet and lower (20%) methane intensity (g/kg ECM) than cows fed the AN:FV mixture. Cows fed all 3 seaweed mixtures had 1.7- to 2.2-fold higher milk iodine concentrations, which showed a week-by-treatment interaction, in that cows fed the AN:FV mixture had higher milk iodine concentrations in wk 3 and 5 of the study. Cows fed the AN:FV also had lower milk urea concentration, suggesting effects of AN or FV bioactive components on rumen protein degradation. Cows fed the AT:AN:FV mixture had lower concentrations of C18:3n-6, and higher concentrations of C15:1 and C17:0, but there were no other effects of feeding seaweed on milk yield or composition. In conclusion, feeding a relatively small amount of AT (0.75 g/kg diet DM) with AN and FV reduced methane emission and yield by 9% and 12%, respectively, and there was no effect of feeding mixtures of AN and FV without AT. Feeding a higher level of AN with FV (5.85 g/kg DM) reduced milk urea concentration, suggesting inhibitory effects of phytotannins or other bioactive components on protein degradation.

Bioactive sulfated fucoidans have high fucose content and are derived from brown seaweeds. Here we report the discovery of the first cold-adapted endo-α(1→3)-fucoidanase (EC 3.2.1.211), Psf1. The psf1 gene was found in the genome of Pseudoalteromonas sp. S3178, a bacterium isolated from a shrimp near Antarctica. Phylogenetic analyses designated Psf1 as a putative member of glycoside hydrolase family 107 (GH107). Substrate selectivity analysis confirmed Psf1 as being endo-acting and indicated that the enzyme catalyzes hydrolysis of α(1→3)-glycosidic fucoidan linkages. Psf1 had temperature optimum of 10-30°C but retained activity at 1°C. Structural modeling indicated similarity to the crystal structure of P5A_FcnA (Psychromonas sp. SW5A), yet distinct high variability regions were identified by RMSF. Psf1 released low molecular weight fucoidan oligosaccharides from Saccharina latissima fucoidan that dose-dependently reduced IL-12p40 secretion in dendritic cells, and lowered IFN-γ and IL-10 levels in dendritic cells co-cultured with allogeneic CD4+ T-cells, without affecting IL-17 secretion, indicating a suppression of Th1-mediated immune response. Treatment of dendritic cells with native fucoidan from S. latissima did not affect cell viability or cytokine secretion. These findings have potential to enable new enzyme-assisted production, at low temperatures, of bioactive fucoidan oligosaccharides from S. latissima grown in the Northern Hemisphere.

Hexagonal boron nitride (hBN) presents valuable intrinsic properties and attracts considerable attention for the development of novel two-dimensional (2D) materials-based technologies. Even though huge efforts have been made to improve the bottom-up synthesis of integrated and high quality hBN, the devices presenting the best performances are still made using hBN exfoliated from bulk crystals. In this context, we explore the Polymer-Derived Ceramics (PDC) route coupled to a high temperature process that produces millimetric and high quality hBN crystals. By investigating the (micro)structure of several samples, we demonstrate that the crystal growth occurs by segregation from a Li3BN2-BN solution upon cooling and from hBN seeds. In particular, we show that crystallization can occur at a temperature as low as 1400{\textdegree}C. Overall, these results show that hBN crystal growth in the Li3BN2-BN system is compatible with conventional flux methods that may be the most promising platform for continuous seeded hBN crystal growth.

Dietary vitamin B12 deficiency is one of the most common micronutrient deficiencies worldwide, with over a billion individuals suffering from low levels of the vitamin. While ruminant-derived meat and dairy products play a crucial role in providing the recommended B12 dietary allowance (2.4 µg/day), increasing the production and consumption of meat and milk entails substantial environmental ramifications. Spirulina blue-green algae (Arthrospira platensis) has been widely proposed as healthier and more sustainable substitutes for meat, milk, and dairy products (also known as meat and milk analogues). However, previous research has shown that while Spirulina contain desirable macro- and micro-nutrients (e.g., essential amino acids, calcium, potassium, magnesium, iron), the majority of vitamin B12 found in so-called traditional Spirulina is a non-active, pseudo-form (cobamide), unavailable to humans, referred to as pseudo-vitamin B12. This renders traditional Spirulina a limited alternative to animal-source foods. As a response, in this exploratory in vitro study, we ask whether light conditions may enhance active vitamin B12 production in Spirulina. We describe the use of scalable photobioreactors, artificially illuminated, located in the Hengill area of Iceland. These systems are used to cultivate Photosynthetically Controlled Spirulina (PCS), to produce carbon–neutral and nutritious biomass containing unopposed, biologically active vitamin B12, in levels comparable to beef (1.64 µg/100g in PCS with a standard deviation of 5% versus 0.7–1.5 μg/100g in beef). In terms of mitigating global vitamin B12 deficiency, we explore production scale up scenarios. In one scenario, by re-allocating the electricity currently consumed by heavy industry, Iceland could produce 277,950 tonnes of Spirulina biomass per year, which translates into approximately 4555 g per year of active vitamin B12, able to meet the recommended dietary allowance (RDA) of over 13.8 million children aged 1–3. More ambitious production scenarios could see Iceland providing the RDA for over 26.5 million children aged 1–3, and over 50 million children aged 0–6 months.

Microorganisms released into the atmosphere by various disturbances can travel significant distances before depositing, yet their impact on community assembly remains unclear. To address this, we examined atmospheric and lithospheric bacterial communities in 179 samples collected at two distinct Icelandic volcanic sites: a small volcanic island Surtsey, and a volcanic highland Fimmvörðuháls using 16S rRNA amplicon sequencing. Airborne microbial communities were similar between sites while significant differences emerged in the communities on lava rocks after 1-year exposure. SourceTracker analysis revealed distinct bacterial populations in the atmosphere and the lava rocks with surrounding soil contributed more significantly to lava rock microbial composition. Nevertheless, shared genera among air, rocks, and local sources, suggested potential exchange between these environments. The prevalent genera shared between rocks and potential sources exhibited stress-resistant properties, likely helping their survival during air transportation and facilitating their colonization of the rocks. We hypothesize that the atmosphere serves as a conduit for locally sourced microbes and stress-resistant distant-sourced microbes. Additionally, bacterial communities on the lava rocks of Fimmvörðuháls showed remarkable similarity after 1 and 9 years of exposure, suggesting rapid establishment. Our study reveals that atmospheric deposition significantly influences bacterial community formation, potentially influencing ecosystem dynamics and microbial communities' resilience.