Matís Staff

Ólafur H. Friðjónsson


Svið: Líftækni

Sími: +354 4225097 /



Erfðatækni, Líftækni, DNA, Ensím, Örverufræði, Þörungar


RITASKRÁ / Publications

RITRÝNDAR GREINAR / Articles in peer-reviewed journals:


Ara K.Z.G., Månberger A., Gabriško M., Linares-Pastén J.A., Jasilionis A, Friðjónsson OH., Hreggviðsson G.H., Janeček S., Karlsson E.N. 2020. Characterization and diversity of the complete set of GH family 3 enzymes from Rhodothermus marinus DSM 4253. Sci Rep 10, 1329 (2020).

Allahgholi L., Sardari R.R.R., Hakvåg S., Ara K.Z.G., Kristjansdottir T., Aasen I.M., Fridjonsson O.H., Brautaset T., Hreggvidsson G.O., Karlsson E.K. 2020. Composition analysis and minimal treatments to solubilize polysaccharides from the brown seaweed Laminaria digitata for microbial growth of thermophiles. J Appl Phycol 32, 1933–1947 (2020).

Nordberg Karlsson E, Sardari RRR, Ron EYC, Bjornsdottir SH, Adalsteinsson BT, Fridjonsson OH, Hreggvidsson GO. 2020. Metabolic engineering of thermophilic bacteria for production of biotechnologically interesting compounds. In: Biotechnological applications of extremophilic microorganisms (ed N Lee) deGruyter, eBook (PDF), ISBN 978-3-11-042433-1. Vol6 of the series “Life in Extreme Environments”. 10.1515/9783110424331-003

Dorawa, S.; Plotka, M.; Kaczorowska, A.-K.; Fridjonsson, O.H.; Hreggvidsson, G.O.; Aevarsson, A.; Kaczorowski, T. Characterization of DNA Polymerase from Thermus thermophilus MAT72 Phage Tt72. Proceedings 2020, 50, 38.

Werbowy O., Stefańska-Kaźmierczak, A., Jurczak-Kurek, A., Kwiatkowska-Semrau, K., Kaczorowska, A-K., Płotka, M., Fridjonsson, OH., Hreggvidsson, OH., Dąbrowski, S.,  Kaczorowski T. 2020. The Characteristics of New SSB Proteins from Metagenomic Libraries and Their Use in Biotech Applications. Viruses 2020 – Novel Concepts in Virology

Kristjansdottir, Th., Ron, E.Y.C., Molins-Delgado D., Fridjonsson, O.H., Turner, C., Bjornsdottir, S.H., Gudmundsson, S., van Niel E. W.J., Karlsson E.N., G.O. Hreggvidsson. 2020. Engineering the carotenoid biosynthetic pathway in Rhodothermus marinus for lycopene production. Metabolic Engineering Communications, Volume 11,

Hreggvidsson, G.; Nordberg-Karlsson, E., Tøndervik, A., Aachmann, F., Dobruchowska, J., Linares-Pastén, J., Daugbjerg-Christensen, M., A., Kristjansdottir, Th., & Sletta, H., Fridjonsson, O., Aasen, I. (2020). Biocatalytic refining of polysaccharides from brown seaweeds. In book: Sustainable Seaweed Technologies (pp.447-504) Chapter: 1610.1016/B978-0-12-817943-7.00016-0.


Rebets Y., Tsolis K., Guðmundsdóttir E., Koepff J., Wawiernia B., Busche T., Bleidt A., Horbal L., Myronovskyi M., Ahmed Y., Wiechert W., Rückert C., Hamed M., Bilyk B., Anne J., Fridjónsson O., Kalinowski J., Oldiges M., Economou T., Luzhetskyy A. 2019. Characterization of sigma factor genes in Streptomyces lividans TK24 using a genomic library-based approach for multiple gene deletions. Frontiers in Microbiology. 9:3033. DOI=10.3389/fmicb.2018.03033


Bjarnadottir, M., Adalbjornsson, B.V., Nilsson, A., Slizyte, R., Roleda, M.Y., Hreggvidsson, G.O., Fridjonsson, O.H., Jonsdottir, R. 2018. Palmaria palmata as an alternative protein source: enzymatic protein extraction, amino acid composition, and nitrogen-to-protein conversion factor. Journal of Applied Phycology. Published online: 13.01.2018.  Grein / Article

Daniels W., Bouvin J, Busche T., Rückert C., Simoens K,. Karamanou S., Van Mellaert L., Fridjonsson O., Nicolai B., Economou A., Kalinowski J., Anné J., Bernaerts K. 2018. Transcriptomic and fluxomic changes in Streptomyces lividans producing heterologous protein. Microbial Cell Factories. 17, 198 doi:10.1186/s12934-018-1040-6


Sardari R.R.R., Kulcinskaja E., Ron E.Y.C., Björnsdóttir S., Friðjónsson O.H., Hreggviðsson, G.Ó., Karlsson E.N. 2017. Evaluation of the production of exopolysaccharides by two strains of the thermophilic bacterium Rhodothermus marinus. Carbohydrate Polymers. 156, 20 1–8.

Gacesa R, Zucko J, Petursdottir SK, Gudmundsdottir EE, Fridjonsson OH, Diminic J, Long PF, Cullum J, Hranueli D, Hreggvidsson GO, Starcevic A. 2017. MEGGASENSE – The Metagenome/Genome Annotated Sequence Natural Language Search Engine: A Platform for the Construction of Sequence Data Warehouses. Food Technol Biotechnol. 55(2):251-257. doi: 10.17113.

Stefaniak-Vidarsson M. M., Kale V. A., Gudjónsdottir M., Marteinsdottir G., Fridjonsson O, Hreggvidsson G.O., Sigurjonsson, O.E., Omarsdottir S., Kristbergsson K. 2017. Bioactive effect of sulphated polysaccharides derived from orange-footed sea cucumber (Cucumaria frondosa) toward THP-1 macrophages. Bioactive Carbohydrates and Dietary Fibre, 12:14-19.

Hreggvidsson G.O., Petursdottir S.K., Stefansson S.K., Björnsdottir S.H., Fridjonsson O.H. 2017. Divergence of Species in the Geothermal Environment. In: Stan-Lotter H., Fendrihan S. (eds) Adaption of Microbial Life to Environmental Extremes. Springer, Cham

Hamed MB, Karamanou S, Ólafsdottir S, Basílio JSM, Simoens K, Tsolis KC, Van Mellaert L, Guðmundsdóttir EE, Hreggvidsson GO, Anné J, Bernaerts K, Fridjonsson OH, Economou A. 2017 Large-scale production of a thermostable Rhodothermus marinus cellulase by heterologous secretion from Streptomyces lividans. Microb Cell Fact. Dec 23;16(1):232. PubMed Central PMCID: PMC5741968.


Dobruchowska J.M., Jonsson J.O., Fridjonsson O.H., Aevarsson A., Kristjansson J.K., Altenbuchner A., Watzlawick H., Gerwig G.J., Dijkhuizen L., Kamerling J.P., and Hreggvidsson G.O. 2016. Modification of linear (β1→3)-linked gluco-oligosaccharides with a novel recombinant β-glucosyltransferase (trans-β-glucosidase) enzyme from Bradyrhizobium diazoefficiens. Glycobiology 36 (11) doi: 10.1093/glycob/cww074.


Ara K.Z.G., Lundemo P., Fridjonsson O.H., Hreggvidson G.O., Adlercreutz P., Karlsson E.N. 2015. A CGTase with high coupling activity using {gamma}-cyclodextrin isolated from a novel strain clustering under the genus Carboxydocella. Glycobiology. 25(5):514-23. Grein / Article

Kale V., Fridjonsson O., Jonsson J.O., Kristinsson H., Ómarsdottir, S, Hreggvidsson G.O. 2015. Chondroitin Lyase from a Marine Arthrobacter sp. MAT3885 for the Production of Chondroitin Sulfate Disaccharides. Marine Biotechnology. 17(4), 479-492. Grein / Article

Rückert C., Albersmeier A., Busche T., Jaenicke S., Winkler, A, Friðjónsson O.H., Hreggviðsson G.Ó., Lambert, C, Badcock D, Bernaerts K, Anne J., Economou A., Kalinowski. 2015. J. Complete genome sequence of Streptomyces lividans TK24. Journal of Biotechnology. 199, 21-22. Grein / Article

Plotka M., Kaczorowska A.-K., Morzywolek A., Makowska J., Kozlowski L. P., Thorisdottir A., Skírnisdottir S., Hjörleifsdottir S., Fridjonsson O., Hreggvidsson G.O., Kristjansson J.K. Dabrowski S., Bujnicki J., Kaczorowski, T. 2015. Biochemical Characterization and Validation of a Catalytic Site of a Highly Thermostable Ts2631 Endolysin from the Thermus scotoductus Phage vB_Tsc2631. PLoS ONE, 10(9), e0137374.


Hjörleifsdottir, S., Blöndal, Th., Ævarsson, A., Fridjonsson, O.H., Ernstsson, S., Hreggvidsson, G.O., Mäntylä, E., Kristjansson, J.K. 2014. Isothermal DNA amplification by a novel and non-ubiquitous Thermus polymerase A. Current Biotechnology. 3(1), 76-86.

Hjörleifsdottir, S., Ævarsson, A., Hreggvidsson, G.O., Fridjonsson, O.H., Kristjansson, J.K. 2014. Isolation, growth and genome of the Rhodothermus RM378 thermophilic bacteriophage. Extremeophiles. 18, 261–270.

Stefanska, A., Kaczorowska, A.K., Plotka, M., Fridjonsson, O.H., Hreggvidsson, G.O., Hjorleifsdottir, S., Kristjansson, J.K., Dabrowski, S., Kaczorowski, T. 2014. Discovery and characterization of RecA protein of thermophilic bacterium Thermus thermophilus MAT72 phage Tt72 that increases specificity of a PCR-based DNA amplification. Journal of Biotechnology. 28,182-183.

Plotka M, Stefanska A, Kaczorowska A-K, Morzywolek A., Fridjonsson O., Dunin-Horkawicz S., Hreggvidsson  G.O., Kristjansson J.K., Dabrowski S., Bujnicki J., and Kaczorowski T. Purification and characterization of a novel highly thermostable lysozyme from Thermus scotoductus MAT2119 bacteriophage Ph2119 that shows amino-acid sequence similarity to eukaryotic peptidoglycan recognition proteins (PGRPs). Applied and Environmental Microbiology. Publishe Online November 2013  Grein / Article

Wang, L., Watzlawick, H., Fridjonsson, O., Hreggvidsson, G., Altenbuchner, J. 2013.  Improved soluble expression of the gene encoding amylolytic enzyme Amo45 by fusion with the mobile-loop-region of co-chaperonin GroES in Escherichia coli. Biocatalysis and Biotransformation. 31(6), 335-342.  Grein / Article

Kale, V., Freysdottir, J., Paulsen, B.S., Friðjónsson, O.H., Hreggviðsson, G.O., Omarsdottir, S. 2013. Sulphated polysaccharide from the sea cucumber Cucumaria frondosa affect maturation of human dendritic cells and theiractivation of allogeneic CD4(þ) T cells in vitro. Bioactive Carbohydrates and Dietary Fibre. 2(2), 108–117. Grein / Article

Zucko, J., Fridjonsson, O.H., Petursdottir, S.K., Gacesa, R., Diminic, J., Long, P.F., Cullum, J., Hranueli, D., Hreggvidsson, G.O., Starcevic, A. 2013. Browsing metagenomes for novel starch and carbohydrate industry enzymes – AMYLOMICS case study. Current Opinion in Biotechnology. 24(Suppl 1), S21-S24. Grein / Article

Kale, V., Björnsdóttir, S.H., Fridjónsson, O.H., Pétursdóttir, S.K., Omarsdóttir, S., Hreggvidsson, G.O. 2013. Litorilinea aerophila gen. nov., sp. nov., an aerobic member of  class Caldilineae, phylum Chloroflexi, isolated from an intertidal hot spring. International Journal of Systematic and Evolutionary Microbiology. 63(3), 1149-1154. Grein / Article  

Schwenteit, J., Bogdanović, X., Fridjonsson, O.H., Aevarsson, A., Bornscheuer, U.T., Hinrichs, W., Gudmundsdottir, B.K. 2013. Toxoid construction of AsaP1, a lethal toxic aspzincin metalloendopeptidase of Aeromonas salmonicida subsp. achromogenes, and studies of its activity and processing. Veterinary Microbiology. 162(2-4), 687-694. Grein / Article

Verspoor, E., Consuegra, S., Fridjonsson, O.H., Hjorleifsdottir, S., Knox, D., Olafsson, K., Tompsett, S., Wennevik, V., de Leaniz, C.G. 2012. Regional mtDNA SNP differentiation in European Atlantic salmon (Salmo salar): an assessment of potential utility for determination of natal-origin. ICES Journal of Marine Science, 69(9), 1625-1636. Grein / Article


Bjornsdottir, S.H., Fridjonsson, O.H., Hreggvidsson, G.O., Eggertsson, G.  2011. Generation of targeted deletions in the genome of Rhodothermus marinus. Applied and Environmental Microbiology. 77(15), 5505-5512.  Grein / Article

Haraldur Bjornsson, Viggo T. Marteinsson, Olafur H. Fridjonsson, Dirk Linke, Eva Benediktsdottir. 2011. Isolation and characterization of an antigen from the fish pathogen Moritella viscosa. Journal of Applied Microbiology. 111(1), 17-25. Grein / Article

Jóhanna Arnórsdóttir, Manuela Magnúsdóttir, Ólafur H. Friðjónsson, Magnús M. Kristjánsson. 2011. The effect of deleting a putative salt bridge on the properties of the thermostable subtilisin-like proteinase, Aqualysin I. Protein & Peptide Letter. 18(6), 545-55. Grein / Article

Olafur Fridjonsson, Kristinn Olafsson, Scott Tompsett, Snaedis Bjornsdottir, Sonia Consuegra, David Knox, Carlos Garcia de Leaniz, Steinunn Magnusdottir, Gudbjorg Olafsdottir, Eric Verspoor, Sigridur Hjorleifsdottir. 2011. Detection and mapping of mtDNA SNPs in Atlantic salmon using high throughput DNA sequencing. BMC Genomics. 12:179. Grein / Article 

Gudmundur O. Hreggvidsson, Justyna M. Dobruchowska, Olafur H. Fridjonsson, Jon O. Jonsson, Gerrit J. Gerwig, Arnthor Aevarsson, Jakob K. Kristjansson, Delphine Curti, Robert R. Redgwell, Carl-Eric Hansen, Johannis P. Kamerling, Takoua Debeche-Boukhit. 2011. Exploring novel non-Leloir {beta}-glucosyltransferases from proteobacteria for modifying linear ({beta}1->3)-linked gluco-oligosaccharidechains. Glycobiology. 21(3), 304-328. Grein / Article

Pauline Vannier, Viggo Thor Marteinsson, Olafur Hedinn Fridjonsson, Philippe Oger, Mohamed Jebbar. Complete genome sequence of the hyperthermophilic piezophilic, heterotrophic and carboxydotrophic archaeon Thermococcus barophilus MP. Journal of Bacteriology. Published Online, January 2011. Grein / Article 


Gudmundur O. Hreggvidsson, Justyna M. Dobruchowska, Olafur H. Fridjonsson, Jon O. Jonsson, Gerrit J. Gerwig, Arnthor Aevarsson, Jakob K. Kristjansson, Delphine Curti, Robert R. Redgwell, Carl-Eric Hansen, Johannis P. Kamerling, Takoua Debeche-Boukhit. Exploring novel non-Leloir {beta}-glucosyltransferases from proteobacteria for modifying linear ({beta}1->3)-linked gluco-oligosaccharidechains. Glycobiology. Published Online Oct 2010. Grein / Article

Arnorsdottir, J., Magnusdottir, M., Fridjonsson, O., Kristjansson, M. 2010. The effect of deleting a putative salt bridge on the properties of the    thermostable subtilisin-like proteinase, aqualysin I. FEBS Journal, 277(Suppl. 1), 251. 

Bryndis Bjornsdottir, Ólafur H. Friðjónsson, Steinunn Magnúsdóttir, Valgerður Andrésdóttir, Guðmundur Ó. Hreggviðsson, and Bjarnheiður K. Guðmundsdóttir. 2009. Characterization of an Extracellular Vibriolysin of the Fish Pathogen Moritella viscoseVeterinary Microbiology. 136 (3-4) 326-334. Grein / Article


Antje Labes, Eva Nordberg Karlsson, Olafur H. Fridjonsson, Pernilla Turner, Gudmundur O. Hreggvidson, Jakob K. Kristjansson, Olle Holst, and Peter Schönheit. 2008. Novel members of glycoside hydrolase family 13 derived from environmental DNA. Applied and Environmental Microbiology 74 (2): 1914-1921. Grein / Article


Björnsdóttir, S., Fridjonsson, O.H., Kristjansson, J.K., Eggertsson, G. 2007. Cloning and expression of heterologous genes in Rhodothermus marinus. Extremophiles, 11:283-293. Grein / Article


Blondal T, Thorisdottir A, Unnsteinsdottir U, Hjorleifsdottir S, Aevarsson A, Ernstsson S, Fridjonsson OH, Skirnisdottir S, Wheat JO, Hermannsdottir AG, Sigurdsson ST, Hreggvidsson GO, Smith AV, Kristjansson JK. 2005. Isolation and characterization of a thermostable RNA ligase 1 from a Thermus scotoductus bacteriophage TS2126 with good single-stranded DNA ligation properties. Nucleic Acids Research, 33:135-42.

Blondal T, Hjorleifsdottir S, Aevarsson A, Fridjonsson OH, Skirnisdottir S, Wheat JO, Hermannsdottir AG, Hreggvidsson GO, Smith AV, Kristjansson JK. 2005. Characterization of a 5′-polynucleotide kinase/3′-phosphatase from bacteriophage RM378. Biol Chem. 280:5188-94.

Turner P, Labes A, Fridjonsson OH, Hreggvidson GO, Schönheit P, Kristjansson JK, Holst O, Karlsson EN. 2005. Two novel cyclodextrin-degrading enzymes isolated from thermophilic bacteria have similar domain structures but differ in oligomeric state and activity profile. Journal of Bioscience and Bioengineering, 100 (4)  380-90.


Birgisson H., Hreggvidsson G.O., Fridjonsson O.H., Mort, A., Kristjansson J.K., Mattiasson B. 2004. Two new thermostable α-L-rhamnosidases from a novel thermophilic bacterium. Enzyme and Microbial Technology. 34:561-571.

Birgisson H, Fridjonsson O, Bahrani-Mougeot FK, Hreggvidsson GO, Kristjansson JK, Mattiasson. 2004. A new thermostable alpha-L-arabinofuranosidase from a novel thermophilic bacterium. B. Biotechnology Letters, 26:1347-51.


Blondal T, Hjorleifsdottir SH, Fridjonsson O. H., Aevarsson A, Skirnisdottir S, Hermannsdottir AG, Hreggvidsson GO, Smith AV, Kristjansson JK. 2003. Discovery and characterization of a thermostable bacteriophage RNA ligase homologous to T4 RNA ligase 1. Nucleic Acids Research, 317247-54.

Cédric F.V. Hobel, Viggó T. Marteinsson, Sigurbjörg Hauksdóttir, Ólafur H. Fridjónsson, Sigurlaug Skírnisdóttir, Gudmundur Ó. Hreggvidsson, Jakob K. Kristjánsson. 2004. Use of low nutrient enrichments to access novel amylase genes in silent diversity of thermophiles. World Journal of Microbiology and Biotechnology, Volume 20 (8), pp. 801-809


Fridjonsson O., Watzlawick H., Mattes R. 2002. Thermoadaptation of α-galactosidase AgaB1 in Thermus thermophilusJournal of Bacteriology, 184(12): 3385-91.


Fridjonsson O., Mattes R. 2001.Production of recombinant α-galactosidases in Thermus thermophilusApplied and Environmental Microbiology, 67(9):4192-8.


Fridjonsson O., Watzlawick H., Mattes R. 2000. The structure of the α-galactosidase gene loci in Thermus brockianus ITI360 and Thermus thermophilus TH125. Extremophiles. 4(1):23-33.


Fridjonsson O., Watzlawick H., Gehweiler A., Rohrhirsch T., and Mattes R. 1999. Cloning of the gene encoding a novel thermostable α-galactosidase from Thermus brockianus ITI360. Applied and Environmental Microbiology, 65(9):3955-63.

Fridjonsson O., Watzlawick H., Gehweiler A., Mattes R. 1999. Thermostable α-galactosidase from Bacillus stearothermophilus NUB3621: cloning, sequencing and characterization. FEMS Microbiology Letters, 176(1):147-53.


Magnusson H.B., Fridjonsson O.H, Andresson O.S, Benediktsdottir E., Gudmundsdottir S., Andresdottir V. 1994. Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish, detected by nested reverse transcription-PCR of 16S rRNA sequences. Applied and Environmental Microbiology, 60(12):4580-3.

Andresson O.S., Fridjonsson O.H . 1994. The sequence of the single 16S rRNA gene of the thermophilic eubacterium Rhodothermus marinus reveals a distant relationship to the group containing Flexibacter, Bacteroides, and Cytophaga species. Journal of Bacteriology, 176(20):6165-9.


Gudmundur O. Hreggvidsson, Solveig Petursdottir, Snaedis Björnsdottir, Olafur H. Fridjonsson. 2011. Microbial speciation in the geothermal ecosystem. In: Adaption of microbial life to environmental extremes : Novel research results and application. edited by Helga Stan-Lotter, Sergiu Fendrihan. Heidelberg, Springer Verlag.


Varsha Kale, Jón Óskar Jónsson, Ólafur Friðjónsson, Sesselja Ómarsdóttir, Guðundur Ó. Hreggviðsson. Erindi 47: Cloning and expression of a chondroitin lyase gene from the marine bacterium Arthrobacter MAT3885 and characterization of the recombinant enzyme. Líffræðirannsóknir á Íslandi. Ráðstefna Líffræðifélags Íslands, Reykjavík, 11.-12. nóvember 2011. 

P.Hamaguchi, M.Geirsdottir, A. Vrac, H. G. Kristinsson, H. Sveinsdottir, O. H. Fridjonsson, G.O. Hreggvidsson. In-vitro antioxidant and antihypertensive properties of Icelandic sea cucumber (Cucumaria frondosa). IFT Annual meeting and food expo, Chicago, 2010. Poster presentation.


Guðmundur Óli Hreggviðsson, Ólafur H. Friðjónsson, Þorleifur Ágústsson, Sigríður Hjörleifsdóttir, Kjell Hellman, Filipe Figueiredo, Helgi Thorarensen. Photoperiod and genetics of growth and maturity in cod (Gadus morhua). Skýrsla Matís 13-10, 43 s. Lokuð skýrsla. Skýrsluágrip.


Elisabet Eik Guðmundsdóttir, Guðmundur Óli Hreggviðsson, Arjan Narbad, Wioleta Trzaska, Ndegwa Maina, Jaana Liimatainen, Maija Tenkanen, Ólafur H. Friðjónsson. 2020 Fermented seaweed based novel feed additives for aquaculture. Provisional patent application IS 050321

Gudmundur O. Hreggvidsson and Olafur H. Fridjonsson. 2019. Methods for Enzymatic Processing of Polysaccharides from Brown algae. PCT/IS2019/050010

Gudmundur O. Hreggvidsson, Jon O. Jonsson, Bryndis Bjornsdottir, Olafur H. Fridjonsson, Josef Altenbuchner, Hilde Watzlawick, Justyna M. Dobruchowska, and Johannis P. Kamerling. 2014. Thermostable alginate degrading enzymes and their methods of use. US provisional patent application.

Aleksandra Stefanska, Olafur H. Fridjonsson, Gudmundur O. Hreggvidsson, Slawomir Dabrowski and Tadeusz Kaczorowski. 2013. Thermostable single-Stranded DNA binding protein and its methods of use. US provisional patent application

S. Hjörleifsdóttir, G.O. Hreggvidsson, O.H. Fridjonsson, A. Ævarsson & J.K. Kristjansson: Nucleic Acid Encoding DNA Polymerase of Bacteriophage RM378, United States Patent Application No. 10/270,786 (2002).

S. Hjörleifsdóttir, G.O. Hreggvidsson, O.H. Fridjonsson, A. Ævarsson & J.K. Kristjansson: RNA Ligase of Bacteriophage RM378, United States Patent No. 6,818,425 (2002).

S. Hjörleifsdóttir, G.O. Hreggvidsson, O.H. Fridjonsson, A. Ævarsson & J.K. Kristjansson: Bacteriphage RM378 of a thermophilic host organism, United States Patent No. 6,492,161 (2000).

Brück T, Fridjonsson OF, Hreggvidsson GO, Kettling U, Kohl A, Koltermann A, Rarbach M, Reisinger C, Unterstrasser I, 2012. Thermostable xylanase for the selective hydrolysis of pentose-containing polysaccharides European patent no. 2516451 A2 Publication date Oct31, 2012.

Gudmundur O. Hreggvidsson, Jon O. Jonsson, Olafur H. Fridjonsson, Justyna M. Dobruchowska, and Johannis P. Kamerling. 2013. Glucan branching enzymes and their methods of use. US patent application filed March 26 2014. PCT/IS2014/050003, WO 2014155395 A2.

Sigríður Hjörleifsdottir, Gudmundur O. Hreggvidsson, Olafur H. Fridjonsson, Arnthor Aevarsson and Jakob K. Kristjansson. Bacteriophage RM 378 of a thermophilic host organisms. US Patent application No. 09/585,959, filed June 2. 1999. Also filed as PCT as well as five divisional US patent applications on genes for RNA ligase, DNA polymerase, DNA helicase, RNase H and 3´-5´exonuclease.

A. Ævarsson, T. Blondal, O.H. Fridjonsson, S. Skirnisdottir, S. Hjörleifsdóttir, G.O. Hreggvidsson & J.K. Kristjansson 2007: Methods of Use for Thermostable RNA Ligases. European patent no. 1546355

Viggo Th. Marteinsson, Cedric Hobel, Gudmundur O. Hreggvidsson, Jakob K. Kristjansson and Olafur H. Fridjonsson. Accessing microbial diversity by ecological methods. US Patent application 09/770,771, filed Jan. 26. 2001

Arnthor Aevarsson, Viggo Th. Marteinsson, Olafur H. Fridjonsson, Gudmundur O. Hreggvidsson and Jakob K. Kristjansson. Method of obtaining protein diversity. Icelandic Patent application no. 5863 filed Feb. 23. 2001 and US No. 09/878,423 filed June 11. 2001.

Gudmundur O. Hreggvidsson, Olafur H. Fridjonsson, Sigurlaug Skirnisdottir and Jakob K. Kristjansson. Retrieval of genes and gene fragments from complex samples. Icelandic Patent application no. 6372 filed May 3. 2002. US patent application no. 10/200,055 filed July 18. 2002.