Complex microbiomes are part of the food we eat and influence our own microbiome, but their diversity remains largely unexplored. Here, we generated the open access curatedFoodMetagenomicData (cFMD) resource by integrating 1,950 newly sequenced and 583 public food metagenomes. We produced 10,899 metagenome-assembled genomes spanning 1,036 prokaryotic and 108 eukaryotic species-level genome bins (SGBs), including 320 previously undescribed taxa. Food SGBs displayed significant microbial diversity within and between food categories. Extension to >20,000 human metagenomes revealed that food SGBs accounted on average for 3% of the adult gut microbiome. Strain-level analysis highlighted potential instances of food-to-gut transmission and intestinal colonization (e.g., Lacticaseibacillus paracasei) as well as SGBs with divergent genomic structures in food and humans (e.g., Streptococcus gallolyticus and Limosilactobabillus mucosae). The cFMD expands our knowledge on food microbiomes, their role in shaping the human microbiome, and supports future uses of metagenomics for food quality, safety, and authentication.
Author: Kristín Edda Gylfadóttir
Sulfation is gaining increased interest due to the role of sulfate in the bioactivity of many polysaccharides of marine origin. Hence, sulfatases, enzymes that control the degree of sulfation, are being more extensively researched. In this work, a novel sulfatase (SulA1) encoded by the gene sulA1 was characterized. The sulA1-gene is located upstream of a chondroitin lyase encoding gene in the genome of the marine Arthrobacter strain (MAT3885). The sulfatase was produced in Escherichia coli. Based on the primary sequence, the enzyme is classified under sulfatase family 1 and the two catalytic residues typical of the sulfatase 1 family—Cys57 (post-translationally modified to formyl glycine for function) and His190—were conserved. The enzyme showed increased activity, but not improved stability, in the presence of Ca2+, and conserved residues for Ca2+ binding were identified (Asp17, Asp18, Asp277, and Asn278) in a structural model of the enzyme. The temperature and pH activity profiles (screened using p-nitrocatechol sulfate) were narrow, with an activity optimum at 40–50 °C and a pH optimum at pH 5.5. The Tm was significantly higher (67 °C) than the activity optimum. Desulfation activity was not detected on polymeric substrates, but was found on GalNAc4S, which is a sulfated monomer in the repeated disaccharide unit (GlcA–GalNAc4S) of, e.g., chondroitin sulfate A. The position of the sulA1 gene upstream of a chondroitin lyase gene and combined with the activity on GalNAc4S suggests that there is an involvement of the enzyme in the chondroitin-degrading cascade reaction, which specifically removes sulfate from monomeric GalNAc4S from chondroitin sulfate degradation products.
Á GAMLÁRSDAG 2020 fundust óvænt nokkrar tómar hnífskeljar (fylking lindýra, Mollusca, flokkur samloka, Bivalvia) í fjöru innst í Hvalfirði. Skeljarnar draga nafn af útlitinu og eru langar, allt að 24 cm, mjóar, þunnar og beittar, og líkjast helst gamaldags rakhnífum. Fyrir fundinn var ekki vitað til þess að áður hefðu fundist hnífskeljar við Ísland, ef frá er talinn fundur tveggja dauðra fáfnisskelja (Ensis magnus) árið 1957 í fjöru í Lónsvík skammt frá bænum Hvalnesi. Eftir fundinn 2020 fannst í febrúar 2021 lifandi samloka í fjörunni við ósa Hafnarár í mynni Borgarfjarðar. Í kjölfar vettvangsferða höfunda og kynningu fyrstu rannsóknarniðurstaðna á Líffræðiráðstefnu haustið 2021, sem leiddu til umfjöllunar í fjölmiðlum um fundina, bárust fleiri tilkynningar um fundi bæði lifandi og dauðra hnífskelja. Þar á meðal í Kollafirði í maí 2019 og Leiruvogi í febrúar 2020. Fundust skeljar allt að 20 cm langar. Þegar þetta er ritað hefur skelin aðeins fundist við suðaustanverðan Faxaflóa. Í norðanverðu Atlantshafi eru þekktar átta tegundir hnífskelja. Þær eru líkar í útliti og getur verið erfitt að greina þær að. Niðurstöður erfðagreiningar lifandi eintaka í rannsókninni sem hér um getur staðfesta að um er að ræða tegundina Ensis terranovensis, sem við nefnum „sindraskel“. Tegundin hefur til þessa einungis fundist við Nýfundnaland á austurströnd Norður-Ameríku, og var þar fyrst greind árið 2012. Ísland er því fyrsta landið þar sem sindraskel finnst utan náttúrulegra heimkynna. Hún hefur sennilega borist hingað sem lirfa í kjölvatni flutningaskipa, jafnvel fyrir rúmum tíu árum ef mið er tekið af stærstu eintökunum sem hér hafa fundist og áætluðum vexti skeljanna. Flutningur sjávarlífvera af mannavöldum út fyrir náttúruleg heimkynni fer vaxandi. Þar sem framandi tegundir ná fótfestu geta þær breytt og/eða valdið skaða á lífríkinu sem fyrir er. Þess vegna er m.a. mikilvægt að fylgjast með útbreiðslu og lifnaðarháttum sindraskeljarinnar hér við land.
Seaweeds (macroalgae) are an attractive resource for diverse microbial- and enzymatic production processes. They are abundant, underutilized, cheap, and rich in carbohydrates, and therefore have the potential to be used as a source of mono- or oligosaccharides, and as substrates for industrial fermentation processes. Many seaweed polysaccharides, including the sulfated polysaccharides ulvan and fucoidan, are however complex and heterogenous in structure, and there are currently few enzymes available to modify them, and understanding of their enzymatic depolymerization remains limited. The present study aimed to identify and characterize robust fucoidanases and ulvan lyases. Metagenomes were obtained from microbial enrichments from an intertidal hot-spring, genes identified that expressed putative fucoidanases and ulvan lyases, and following gene cloning and expression, the respective enzymes were screened for enzymatic activity. Consistent with their origin, the identified protein sequences were considerably divergent from previously characterized enzymes, with a 44 % average maximal sequence identity. In total, the study resulted in the characterization of 10 new fucoidanases (GH107 and GH168 families) and 8 new ulvan lyases (PL24, PL25 and PL40 families). Notably, the new fucoidanases appeared to have functional specificity towards fucoidan containing α-1,3 linked L-fucosyl and several functioned at high temperature. The study contributes a metagenomics-based approach to identify new seaweed polysaccharide degrading enzymes and an increased understanding of the diversity of such enzymes, which may have implications for the realization of biotechnology based valorization of seaweed biomass.
As the global population continues to grow, so does the demand for longer, healthier lives and environmentally responsible choices. Consumers are increasingly drawn to naturally sourced products with proven health and wellbeing benefits. The marine environment presents a promising yet underexplored resource for the cosmetics industry, offering bioactive compounds with the potential for safe and biocompatible ingredients. This manuscript provides a comprehensive overview of the potential of marine organisms for cosmetics production, highlighting marine-derived compounds and their applications in skin/hair/oral-care products, cosmeceuticals and more. It also lays down critical safety considerations and addresses the methodologies for sourcing marine compounds, including harvesting, the biorefinery concept, use of systems biology for enhanced product development, and the relevant regulatory landscape. The review is enriched by three case studies: design of macroalgal skincare products in Iceland, establishment of a microalgal cosmetics spin-off in Italy, and the utilization of marine proteins for cosmeceutical applications.
Seaweed is a great source of biologically active metabolites which could prove interesting in cosmeceutical applications. In this study, seven Icelandic seaweed species (Ascophyllum nodosum, Alaria esculenta, Laminaria hyperborea, Digital Laminaria, Saccharina latissima, Palmaria palmata, and Schizymenia jonssonii) were screened for total polyphenol content, antioxidant properties, and inhibition of skin-degrading enzymes. Antioxidant assays included DPPH (2,2-diphenyl-1-picrylhydrazyl), reducing power, and ORAC (oxygen radical absorbance capacity). In most assays, A. nodosum extracts were the most active. A. nodosum extracts also showed the strongest inhibition of the skin-degrading enzymes elastase and collagenase at low concentrations, demonstrating its skin-protective qualities. To further investigate the activity, A. nodosum was subsequently extracted with solvents with increasing polarity into seven different extracts. Compared to other extracts, the extracts obtained by extraction with acetone and methanol showed the highest activity in all assays. Extracts obtained with room-temperature water and 85 °C water also demonstrated moderate to high activities. The outcomes of this study support the potential utilization of the brown seaweed A. nodosum as a source of natural ingredients in cosmeceuticals.
Contact
Ólafur Reykdal
Project Manager
olafur.reykdal@matis.is
Markmið verkefnisins um kryddjurtir var að rannsaka áhrif kryddjurta á geymsluþol matvæla en mikill áhugi er á hagnýtingu náttúrulegra hráefna í stað rotvarefna til að ná viðunandi geymsluþoli matvæla. Í verkefninu var athyglinni fyrst og fremst beint að einni kryddjurt, sítrónumelissu. Ljóst er að sítrónumelissan býr yfir andoxunarvirkni samkvæmt mælingum í verkefninu. Andoxunarefnin gegna mikilvægu hlutverki fyrir heilsu, þau sporna gegn myndun skaðlegra efna í líkamanum og draga úr óæskilegum breytingum.
Í verkefninu kom í ljós að þættir í sítrónumelissu geta hamlað fjölgun örvera og að sítrónumelissa er því meðal mögulegra hráefna sem geta lengt geymsluþol matvæla. Á þessu stigi er þó ekki tímabært að nota sítrónumelissu alfarið í stað rotvarefna sem fram til þessa hafa verið nauðsynleg fyrir matvælaöryggi. Þessa þróun ætti að taka í varfærnum skrefum og fylgjast með öryggi afurðanna. Hafa má í huga að notkun sítrónumelissu í matvæli treystir hollustuímynd varanna vegna andoxunarefna, vítamína og annarra næringarefna. Í tilraunum kom í ljós að sítrónumelissa hamlaði gegn vexti örvera við vissar aðstæður. Pressaður safi úr sítrónumelissu var til skoðunar og býður hann upp á hagnýtingu. Við geymslu á sítrónumelissu og fleiri kryddjurtum við 3-4 °C kom í ljós að skemmdarferlar gengu hægt fyrir sig.
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Lemon balm is a plant that belongs to the group of herbs. In this project the properties of lemon balm were studied to test if the plant could be used to prolong shelf life of processed foods and thus replace food additives.
Considerable antioxidant activity was measured in lemon balm. It was also found that lemon balm can act as an antimicrobial agent to delay the growth of bacteria in fish balls and meat balls. The antimicrobial activity was dependent on the form of lemon balm. Lemon balm juice can be used in product development.
Lemon balm added to processed foods will provide increased content of antioxidants and vitamins. The use of lemon balm to replace preservatives should only be used stepwise and safety of the food should be checked during changing of recipes.
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Contact
Elísabet Eik Guðmundsdóttir
Project Manager
elisabet@matis.is
Þessi skýrsla er lokuð.
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Contact
Guðrún Svana Hilmarsdóttir
Specialist
gudrun.svana@matis.is
Understanding and reducing the greenhouse gas emissions of bottom trawl fisheries is of importance, as it directly impacts efforts to mitigate climate change and promotes sustainable fishing practices. As a considerable part of global landings is fished using demersal trawls and vessel renewal is often mentioned as an important mitigation measure. This study compares the greenhouse gas emissions of older and newer trawlers in the Icelandic fleet, using Life Cycle Assessment methodology with the functional unit "1 kg of demersally trawled fish at landing". The global warming potential (kg CO2-eq) from older Icelandic bottom trawlers was assessed and compared to the newer ones, where older vessels were in some cases being decommissioned. A total of 11 trawlers were assessed, providing a cross section of the Icelandic bottom trawler fleet, with respect to age, size, catch composition and onboard operations. The results show that freezer trawling was more energy-intensive compared to trawlers landing their catches chilled/superchilled. Fleet renewal alone does not explain the reduction in fuel use and greenhouse gas emissions in the Icelandic bottom trawl fleet between 2012 and 2022, highlighting the need for a comprehensive approach considering multiple factors such as catch composition, fishing ground, and vessel characteristics, which explained 87% of the emissions. Catching indicated increased fuel consumption compared to steaming. The greenhouse gas emissions allocated to each demersal fish species ranged on average from 0.5 to 1.0 kg CO2-eq/kg of the weight of demersal fish landed, and from 1.4 to 2.7 kg CO2-eq/kg of the edible part of demersal fish landed (mass allocation), where redfish stood out as having the highest emissions.
Contact
Guðjón Þorkelsson
Strategic Scientist
gudjon.thorkelsson@matis.is
Fat explosion has not been measured during the quality assessment of lamb and ewe carcasses because it is not possible to visually assess muscle since the carcasses are not cut after cooling in slaughterhouses. It is changing. Australia, the world's largest lamb exporter, has adopted intramuscular fat as a breeding target. In order to breed and pay farmers for fat in the muscles of lamb carcasses, fast and automatic measurements of hot carcasses on the slaughter line are needed. Meat and Livestock Australia and public bodies have supported the development and testing of meters based on different technologies. One meter has been certified and is being tested/used in several abattoirs in Australia and New Zealand. The meter is from Meqprobe and is based on probes being inserted into the warm back muscle on the slaughter line, which assess intramuscular fat using laser technology.
Other measures, such as optical imaging (OCT), based on the adaptation of needles used in medical imaging to measure intramuscular fat and other properties, and magnetic resonance imaging (NMR) are still under development.
The purpose of including intramuscular fat in the quality assessment is to make lamb meat from Australia stand out in demanding markets in other countries that are willing to pay a higher price for higher taste quality.
We are considering whether to breed for intramuscular fat in Icelandic sheep. Conditions in Iceland are completely different from Australia, where about 25 million lambs are slaughtered per year, the age at slaughter is 6-8 months, the average weight is 25 kg, and about 70% of the production is sold abroad. The slaughterhouses in Iceland might be too small to cover the costs of an objective assessment of muscle fat, and there is also a question as to whether it serves any purpose both for farmers and different markets. Another option is to focus on breeding and measure intramuscular fat in the back muscles of lambs from progeny research farms the day after slaughter in cold slaughterhouses. The carcasses would then have to be cut to access the spinal muscles of the lambs and NIR meters or imaging should be used to measure fat in the muscles.
The NIR meter from the company SOMA OPT has been certified in Australia to measure intramuscular fat in the spinal muscles of lamb carcasses. Imaging equipment for beef is also being adapted to lamb meat. It is also interesting to observe the development of technology for image analysis with ordinary mobile phones.
It is also interesting to see if it will be possible to use ultrasound on live cattle to tell about intramuscular fat. This report is a summary of the development of instrumentation in relation to intramuscular fat in lambs in Australia and New Zealand. It is part of the project "Fat blasting in lamb meat", which is funded by Development Fund for Sheep Farming.
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Marbling of muscle is now a sheep breeding objective in Australia and New Zealand. Marbling has in breeding programs been evaluated in the loin muscles of carcasses of lambs from progeny testing either by sampling muscle for chemical analysis or measuring samples or muscle surfaces by Near Infrared Reflectance (NIR) instruments. Rapid, accurate and reliable techniques for measuring intramuscular fat in loin muscles of lamb carcasses are needed if it is to be included in the price to farmers, grading and further processing and marketing. This is being done in Australia and New Zealand. Different technologies have been developed and tested with the support of MLA (Meat and Livestock Australia).
Online technologies of interest include:
"MEQ (Meat Eating Quality) probe" is an industry applicable technology to estimate intramuscular fat (IMF) percent in lamb by inserting laser-based probes in the loin muscle of hot carcasses. It has been granted conditional AUS-MEAT accreditation to measure IMF% in hot lamb carcasses and is being used and tested in abattoirs in Australia and New Zealand.
The start up company Miniprobes has developed a needle with a fiber optic probe to measure IMF based on optical coherence tomography (OCT).
The company AMPC is developing the Marbl™ technology using a single-sided nuclear magnetic resonance sensor alongside the longissimus muscle to capture IMF measurements without penetrating the carcass.
NIR analyzer from the company SOMA OPT has been accredited Australia for estimating intramuscular fat in lamb loin muscles. It is based on cut carcass technology which can be used in research and progeny testing.
Including intramuscular fat as a breeding goal in sheep production in Iceland is being considered. It is still too early to say if it is feasible. Data must be collected from progeny testing for many years using the SOM OPT NIR meter or similar tools to see if there is enough genetic variation to justify intramuscular fat as a breeding objective. The small size of sheep production in Iceland with around 400 thousand lambs slaughtered in 8 weeks each year in 3-4 abattoirs will probably make it too expensive to adapt sophisticated online technologies to measure and use intramuscular fat to control and improve the eating quality of the meat.