Author: hilduryr@matis.is

News

Doctoral defense in biology – Pauline Anne Charlotte Bergsten

Next Monday, September 12, Pauline Bergsten will defend her doctoral thesis in biology. The project is called: Exploration of the Microbial Communities within the Basaltic Subsurface of the Volcanic Island Surtsey in Iceland

The doctoral defense takes place in The Aula of the HÍ main building and starts at 10:00.

Opponents:
Dr. Steffen L. Jörgensen, associate professor at the University of Bergen, Norway
Dr. Odd Þ. Vilhelmsson, professor at the University of Akureyri.

Advisor Dr. Viggó Þór Marteinsson, Professor at the Faculty of Food Science and Nutrition , University of Iceland and Research Group Leader at Matís

Doctoral committee:
Dr. Pauline Vannier, project manager at Matís
Dr. Snædís H. Björnsdóttir, associate professor at the Faculty of Life and Environmental Sciences of the University of Iceland

Chair of Ceremony: Dr. Snæbjörn Pálsson, Professor and Head of the Faculty of Life and Environmental Sciences, University of Iceland

Abstract
Surtsey is a volcanic island located on the south-east offshore extension of the Icelandic rift zone. It was formed during successive eruptions from the seafloor in 1963-1967 and has been officially protected and studied ever since. It represents an exceptional natural setting for studying colonization and succession of life on land. Also for subsurface microbial communities associated with newly formed basaltic tuff deposits in a seawater-hydrothermal system that is still active and at temperatures approaching the presumed thermal limit for functional life.
During an international drilling operation at Surtsey in 2017, drill core samples at successive depths as well as associated hot fluids and surface fumes from fumaroles were collected for microbial investigations. This thesis presents the first and most comprehensive research of the Surtsey subsurface biosphere. Multiple approaches were combined on the rare and unique samples to increase the knowledge of microbial communities inhabiting the oceanic subsurface and of the processes that sustain such life.
These included molecular analyses of environmental DNA through 16S rRNA gene amplicon and metagenome sequencing, isolation and characterization of bacterial strains and microscopic investigations. Based on the DNA concentration, the microbial cell numbers present in the drill cores were estimated to range from about 5×104 to 1×106 cells per gram of sample.
The Surtsey subsurface is therefore a low biomass environment, making the samples extremely sensitive to external contamination. It is nevertheless a diverse habitat that hosts bacterial and archaeal clades, including extremophiles, that have been previously detected in other terrestrial and marine environments. Yet, many clades belonged to unknown lineages. Predictive functional analyses based on taxonomic identifications revealed that the Surtsey subsurface biosphere is composed of heterotrophic microorganisms as well as chemoautotrophs involved in the sulfur, nitrogen, and methane cycles. However, these results could not be strengthened by the functional metagenomic investigations as they were inconclusive. Numerous enrichment cultures were initiated using different conditions and media and resulted in nearly 200 isolated bacterial strains, which included several novel species. One novel thermophilic bacterial species, Rhodothermus bifroesti, was fully characterized and its genome was sequenced and compared with those of the two other described Rhodothermus species. Comparative analyses revealed that 2.15% of the amplicon sequence variants from the 16S rRNA gene amplicon sequence datasets were represented by cultivated strains using standard methods. Finally, putative microbial structures adhering to the basaltic tuff were discovered inside the numerous interconnected vesicles found in the basaltic glass.
All of the findings point to an active microbial colonization of the Surtsey deposits within 50 years after the eruptions ended, with possible sources of colonization coming from the surrounding ecosystems via microbial dissemination and possible adaptations.
The thesis establishes a foundation for future research on the microbial communities that inhabit the Surtsey subsurface and their temporal succession in the face of a cooling and changing hydrothermal environment.

More information can be found by clicking here.

News

The Farmers' Association of Iceland visited Matís

The Farmers' Association of Iceland visited us in Matís last September 7. Gunnar Þorgeirsson, chairman, Vigdís Häsler, managing director, and Guðrún Birna Brynjarsdóttir, expert, examined the progress in the tissue culture of seed potatoes that Matís is carrying out for the Farmers Association. Other collaborative projects were also reviewed, but they are numerous and the aim is to increase them even further in the future.

Below you can see pictures of tissue cultured potatoes grown by Matís.

Matís thanks the Farmers' Association of Iceland for coming and looks forward to continued good cooperation. 

Peer-reviewed articles

Basalt-Hosted Microbial Communities in the Subsurface of the Young Volcanic Island of Surtsey, Iceland

Contact

Pauline Bergsten

Ph.D. Student

paulineb@matis.is

The island of Surtsey was formed in 1963–1967 on the offshore Icelandic volcanic rift zone. It offers a unique opportunity to study the subsurface biosphere in newly formed oceanic crust and an associated hydrothermal-seawater system, whose maximum temperature is currently above 120 ° C at about 100m below surface. Here, we present new insights into the diversity, distribution, and abundance of microorganisms in the subsurface of the island, 50years after its creation. Samples, including basaltic tuff drill cores and associated fluids acquired at successive depths as well as surface fumes from fumaroles, were collected during expedition 5059 of the International Continental Scientific Drilling Program specifically designed to collect microbiological samples. Results of this microbial survey are investigated with 16S rRNA gene amplicon sequencing and scanning electron microscopy. To distinguish endemic microbial taxa of subsurface rocks from potential contaminants present in the drilling fluid, we use both methodological and computational strategies. Our 16S rRNA gene analysis results expose diverse and distinct microbial communities in the drill cores and the borehole fluid samples, which harbor thermophiles in high abundance. Whereas some taxonomic lineages detected across these habitats remain uncharacterized (eg, Acetothermiia, Ammonifexales), our results highlight potential residents of the subsurface that could be identified at lower taxonomic rank such as Thermaerobacter, BRH-c8a (Desulfallas-Sporotomaculum), Thioalkalimicrobium, and Sulfurospirillum. Microscopy images reveal possible biotic structures attached to the basaltic substrate. Finally, microbial colonization of the newly formed basaltic crust and the metabolic potential are discussed on the basis of the data.

Link to article

Peer-reviewed articles

Cultivable Bacterial Diversity from the Basaltic Subsurface of the Young Volcanic Island of Surtsey, Iceland

Contact

Pauline Bergsten

Ph.D. Student

paulineb@matis.is

The oceanic crust is the world's largest and least explored biosphere on Earth. The basaltic subsurface of Surtsey island in Iceland represents an analogue of the warm and newly formed oceanic crust and offers a great opportunity for discovering novel microorganisms. In this study, we collected borehole fluids, drill cores, and fumarole samples to evaluate the culturable bacterial diversity from the subsurface of the island. Enrichment cultures were performed using different conditions, media and temperatures. A total of 195 bacterial isolates were successfully cultivated, purified, and identified based on MALDI-TOF MS analysis and by 16S rRNA gene sequencing. Six different clades belonging to Firmicutes (40%), Gammaproteobacteria (28.7%), Actinobacteriota (22%), Bacteroidota (4.1%), Alphaproteobacteria (3%), and Deinococcota (2%) were identified. Bacillus (13.3%) was the major genus, followed by Geobacillus (12.33%), Enterobacter (9.23%), Pseudomonas (6.15%), and Halomonas (5.64%). More than 13% of the cultured strains potentially represent novel species based on partial 16S rRNA gene sequences. Phylogenetic analyzes revealed that the isolated strains were closely related to species previously detected in soil, seawater, and hydrothermal active sites. The 16S rRNA gene sequences of the strains were aligned against Amplicon Sequence Variants (ASVs) from the previously published 16S rRNA gene amplicon sequence datasets obtained from the same samples. Compared with the culture-independent community composition, only 5 out of 49 phyla were cultivated. However, those five phyla accounted for more than 80% of the ASVs. Only 121 out of a total of 5642 distinct ASVs were culturable (≥98,65% sequence similarity), representing less than 2,15% of the ASVs detected in the amplicon dataset. Here, we support that the subsurface of Surtsey volcano hosts diverse and active microbial communities and that both culture-dependent and -independent methods are essential to improving our insight into such an extreme and complex volcanic environment.

Link to article

Peer-reviewed articles

Rhodothermus bifroesti sp. nov., a thermophilic bacterium isolated from the basaltic subsurface of the volcanic island Surtsey

Contact

Pauline Bergsten

Ph.D. Student

paulineb@matis.is

Novel thermophilic heterotrophic bacteria were isolated from the subsurface of the volcanic island Surtsey off the south coast of Iceland. The strains were isolated from tephra core and borehole fluid samples collected below 70 m depth. The Gram-negative bacteria were rod-shaped (0.3–0.4 µm wide, 1.5–7 µm long), aerobic, non-sporulating and non-motile. Optimal growth was observed at 70 °C, at pH 7–7.5 and with 1% NaCl. Phylogenetic analysis identified the strains as members of the genus Rhodothermus. The type strain, ISCAR-7401 T, was genetically distinct from its closest relatives Rhodothermus marinus DSM 4252 T and Rhodothermus profundi PRI 2902 T based on 16S rRNA gene sequence similarity (95.81 and 96.01%, respectively), genomic average nucleotide identity (73.73 and 72.61%, respectively) and digital DNA–DNA hybridization (17.6 and 16.9%, respectively). The major fatty acids of ISCAR-7401 T were iso-C 17:0, anteiso-C 15:0, anteiso-C 17:0 and iso-C 15:0 (>10 %). The major isoprenoid quinone was MK-7 while phosphatidylethanolamine, diphosphatidylglycerol, an unidentified aminophospholipid and a phospholipid were the predominant polar lipid components. Based on comparative chemotaxonomic, genomic and phylogenetic analyses, we propose that the isolated strain represents a novel species of the genus Rhodothermus with the name Rhodothermus bifroesti sp. Nov. The type strain is ISCAR-7401 T (=DSM 112103 T =CIP 111906 T).

Link to article

Peer-reviewed articles

SUSTAIN drilling at Surtsey volcano, Iceland, tracks hydrothermal and microbiological interactions in basalt 50 years after eruption

Contact

Pauline Bergsten

Ph.D. Student

paulineb@matis.is

The 2017 Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes (SUSTAIN) drilling project at Surtsey volcano, sponsored in part by the International Continental Scientific Drilling Program (ICDP), provides precise observations of the hydrothermal, geochemical, geomagnetic, and microbiological changes that have occurred in basaltic tephra and minor intrusions since explosive and effusive eruptions produced the oceanic island in 1963–1967. Two vertically cored boreholes, to 152 and 192 m below the surface, were drilled using filtered, UV-sterilized seawater circulating fluid to minimize microbial contamination. These cores parallel a 181 m core drilled in 1979. Introductory investigations indicate changes in material properties and whole-rock compositions over the past 38 years. A Surtsey subsurface observatory installed to 181 m in one vertical borehole holds incubation experiments that monitor in situ mineralogical and microbial alteration processes at 25–124 ∘C. A third cored borehole, inclined 55∘ in a 264∘ azimuthal direction to 354 m measured depth, provides further insights into eruption processes, including the presence of a diatreme that extends at least 100 m into the seafloor beneath the Surtur crater. The SUSTAIN project provides the first time-lapse drilling record into a very young oceanic basaltic volcano over a range of temperatures, 25–141 ∘C from 1979 to 2017, and subaerial and submarine hydrothermal fluid compositions. Rigorous procedures undertaken during the drilling operation protected the sensitive environment of the Surtsey Natural Preserve.

Link to article

Peer-reviewed articles

Impact of onboard chitosan treatment of whole cod (Gadus morhua) on the shelf life and spoilage bacteria of loins stored superchilled under different atmospheres

Contact

Pauline Bergsten

Ph.D. Student

paulineb@matis.is

The initial handling of marine fish on board fishing vessels is crucial to retain freshness and ensure an extended shelf life of the resulting fresh products. Here the effect of onboard chitosan treatment of whole, gutted Atlantic cod (Gadus morhua) was studied by evaluating the quality and shelf life of loins processed six days post-catch and packaged in air or modified atmosphere (% CO2/ O2/ N2: 55/5/40) and stored superchilled for 11 and 16 days, respectively. Sensory evaluation did not reveal a clear effect of chitosan treatment on sensory characteristics, length of freshness period or shelf life of loins under either packaging conditions throughout the storage period. However, directly after loin processing, microbiological analysis of loins showed that onboard chitosan treatment led to significantly lower total viable counts as well as lower counts of specific spoilage organisms (SSO), such as H2S-producers and Pseudomonas spp., compared to the untreated group. In addition, the culture-independent approach revealed a lower bacterial diversity in the chitosan-treated groups compared to the untreated groups, independently of packaging method. Partial 16S rRNA gene sequences belonging to Photobacterium dominated all sample groups, indicating that this genus was likely the main contributor to the spoilage process.

Link to article

News

Conference on September 8. Innovation and opportunities in Icelandic food production

Orkídea and the University of Iceland are holding a conference on innovation and opportunities in food production on September 8 at Hotel Selfoss. Matís employees Rósa Jónsdóttir and Kolbrún Sveinsdóttir will give a presentation on the production of new proteins for food and feed.

It is imperative to increase food production in the world significantly in the coming decades due to the ever-growing world population. This poses great challenges, as a large part of the world's usable vegetation is already used for agricultural production. Many usable fish stocks have reached their endurance limit and there is a growing shortage of energy and water for food production. These challenges also contain great opportunities for Iceland, which the intention is to shed light on at this event, which is a joint project of Orkídea, the Icelandic University of Agriculture, the Ministry of University, Industry and Innovation, the University of Bifröst, Íslandstofa, Lax-inn Education Center, Matís, the Agricultural Advisory Center, Association of small food producers and Ölfus Cluster.

Video recordings from the conference can be found by clicking the button below:

Video recordings

The conference program can be found here:

Moderator: Vigdís Häsler, executive director Farmers' Association of Iceland

News

Matís comes to the search for genetic factors of bow crisis

Bógkreppa is a hereditary genetic defect in sheep in Iceland. The defect is likely to be recessive, meaning that in order for lambs to be born with the symptoms of rickets, they must receive the defective gene from both parents. This means that the genetic defect has been hidden for years in the Icelandic treasury and then unexpectedly pops up.

Matís is involved in a project that aims to find a genetic marker that could be used to diagnose the defect in heterozygous individuals. If such a genetic marker were found, it would be possible to eliminate the genetic defect from Icelandic cattle and ensure that it does not enter insemination centers.

The research project is funded by the Professional Council for Sheep Breeding, led by the University of Iceland's Institute of Pathology at Keldum, and in addition to Matís, RML is involved in the project.

See more on the Bændablaðir website by clicking here

Photo: Shutterstock

News

Genetic modification of microorganisms

The guests of the Matvælið podcast this time are Björn Þór Aðalsteinsson, project manager at Matís and Tryggvi Stefánsson, assistant manager at Algalíf. In the episode, they review marketing and research considerations in relation to genetic modification of microbes.

Björn Þór tells us about the Thermo-Tools project that Matís' biotechnology group has been working on for the past few years. The Thermo Tools project aims to develop new tools to genetically modify thermophilic microbes. Iceland has the unique feature of having a large amount of hot springs and, as a result, very good access to heat-loving microbes. Thermophilic microbes live at very high temperatures, ranging from 50-121°C, and the problem lies in the fact that the devices and tools normally used for genetic modification do not work at such high temperatures.

Tryggvi Stefánsson from Algalíf tells us about their production of Astaxanthin and how the market in which Algalíf operates sets a clear policy against genetic modification and the importance of having non-GMO certification in their production.

Listen to the full episode below:

The host is Ísey Dísa Hávarsdóttir

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