Gunn Merethe Bjørge Thomassen

Research

Through most of my professional career I have worked within the field of microbiology, with pathogenic bacteria and how they pose a threat to humans. And the aim in several of the projects I have worked on has been to gain more knowledge about the microorganisms in focus, to be able to develop strategies to prevent people being harmed by them. In my research I use both conventional microbiological methods, molecular methods and sequencing based methods and, I am working on improving my knowledge and skills within bioinformatics and analyzing large amounts of data. In food microbiology, conventional microbiological methods have been of outermost importance for a long time, and they still are. However, molecular methods and new sequencing technologies are emerging. All these methods have their strengths and weaknesses and I see them as complementary to each other rather than ranging one above the other.

In my Phd thesis I studied the development and dynamics of resilient bacterial communities in the processing environment in a newly opened salmon processing facility. I investigated the problems associated with biofilm and persistence of Listeria monocytogenes and how this is linked to other bacteria as for example Pseudomonas spp.

Currently I work as a Post doc in the project “Hydroponic Plant Cultivation on a Lunar Base Using Nutrient Sources from Human Waste”, where my research responsibility is on the food safety in the hydroponic cultivated plants.

Forskningsgruppe for Matvitenskap

LunarPlant: Hydroponic Plant Cultivation on a Lunar Base Using Nutrient Sources from Human Waste

Prosjektet skal studere komplekse responser hos planter dyrket hydroponisk med næringskilder laget av menneskelig avfall, samt å utvikle infrastruktur for bærekraftig hydroponisk plantedyrking i verdensrommet.

Optimal utnyttelse av havets matressurser (OPTiMAT)

OPTiMAT vil ha hovedfokus i den delen av verdikjeden som innbefatter ressursene etter at de er tatt opp fra havet og innovative løsninger for å bearbeide disse til trygge og lønnsomme forbrukerprodukter av høy kvalitet.

Kartlegging av listeria i sjøfasen ved produksjon av atlantisk laks (TRACEListeria)

Prosjektet skal øke kunnskapen om fôr, oppdrett og dets betydning for kontaminering av L. monocytogenes i verdikjede laks ved å dokumentere smitteveier for L. monocytogenes fra fôrprodusenter via matfiskanlegg og videre til ferdig pakket fisk.

Publications

2023

Thomassen, Gunn Merethe Bjørge; Reiche, Thorben; Hjørungnes, Martinus; Mehli, Lisbeth. (2023) High Disinfectant Tolerance in Pseudomonas spp. Biofilm Aids the Survival of Listeria monocytogenes. Microorganisms
Academic article

2022

Thomassen, Gunn Merethe Bjørge; Mehli, Lisbeth. (2022) Gjenstridige bakteriesamfunn i lakseslakteri. Norsk Sjømat
Popular scientific article
Thomassen, Gunn Merethe Bjørge; Krych, Lukasz; Knøchel, Susanne; Mehli, Lisbeth. (2022) Bacterial community development and diversity during the first year of production in a new salmon processing plant. Food Microbiology
Academic article
Thomassen, Gunn Merethe Bjørge. (2022) Resilient bacterial communities in a salmon processing environment - The impact on food safety. NTNU Open
Doctoral dissertation
Thomassen, Gunn Merethe Bjørge; Reiche, Thorben; Tennfjord, Christine Eikås; Mehli, Lisbeth. (2022) Antibiotic Resistance Properties among Pseudomonas spp. Associated with Salmon Processing Environments. Microorganisms
Academic article

2021

Thomassen, Gunn Merethe Bjørge; Krych, Lukasz; Knøchel, Susanne; Mehli, Lisbeth. (2021) ON-rep-seq as a rapid and cost-effective alternative to whole-genome sequencing for species-level identification and strain-level discrimination of Listeria monocytogenes contamination in a salmon processing plant. MicrobiologyOpen
Academic article
Bringsli, Renate; Mehli, Lisbeth; Thomassen, Gunn Merethe Bjørge. (2021) Antimicrobial resistance and biofilm formation among Pseudomonas spp., Serratia spp. and Aeromonas spp. isolated from Norwegian Farmed Salmon . NTNU
Masters thesis
Reiche, Thorben; Mehli, Lisbeth; Thomassen, Gunn Merethe Bjørge. (2021) Phenotypic and Genotypic Characterization of Antimicrobial Resistance in Pseudomonas spp. isolated from the Salmon industry. NTNU
Masters thesis

2020

Umutoni, Noelle; Jakobsen, Anita Nordeng; Mukhatov, Kirill; Thomassen, Gunn Merethe Bjørge; Karlsen, Hanne; Mehli, Lisbeth. (2020) Occurrence, diversity and temperature-dependent growth kinetics of Aeromonas spp. in lettuce. International journal of food microbiology
Academic article
Boyko, Viktoriya; Mehli, Lisbeth; Thomassen, Gunn Merethe Bjørge. (2020) Identifisering av, og biofilmegenskaper blant, Pseudomonas spp. fra et lakseslakteri – påvirkning på vekst og overlevelse av Listeria innocua. NTNU
Masters thesis

2019

Bremvåg, Maja; Mehli, Lisbeth; Thomassen, Gunn Merethe Bjørge. (2019) Forekomst av Listeria spp. i et nyetablert prosesseringsanlegg for laks. NTNU
Masters thesis

Teaching

Courses

I have been teaching laboratory courses in microbiology, biotechnology, and general chemistry at Bachelor level through a period of eight years (2013-2020). In addition, I taught one time a laboratory course in safe food production at Master level. Additionally, I have been holding single lectures on Genetically modified organisms within the subject Food technology for third year students. One semester (autumn 2016) I had the teaching responsibility for two subjects in the Vocational Teacher Education and for a smaller part of a third subject. This included preparing and holding all the lectures in the relevant topics, evaluating exercises, conduct the laboratory exercises, preparing and evaluating exams.

Supervision

During my PhD I was the co-supervisor for six Master students and three Bachelor groups that were doing work related to my Phd-project. In my current position I am/will be the co-supervisor for at least three Bachelor groups and one Master student.

I am always interested in taking on new students that wants to do their thesis within my field of research.

Outreach

2024

Academic lecture

Thomassen, Gunn Merethe Bjørge. (2024) Persistence of foodborne pathogens during hydroponic cultivation of lettuce on nutrients based on source-separated urine. International Committee on Food Microbiology and Hygiene FoodMicro 2024, 28th International ICFMH Conference , Burgos 2024-07-08 - 2024-07-11

2023

Poster

Thomassen, Gunn Merethe Bjørge; Sandberg, Martin; Jakobsen, Øyvind Mejdell; Schiefloe, Mona; Kittang, Ann-Iren; Mehli, Lisbeth. (2023) Growth and survival of bacterial pathogens in plant nutrient solutions based on human waste. EFFoST 37th EFFoST International Conference 2023 , Valencia 2023-11-06 - 2023-11-08
Lecture

Thomassen, Gunn Merethe Bjørge. (2023) Hydroponic Plant Cultivation on a Lunar Base Using Nutrient Sources from Human Waste. Teagasc Food Bioscience, V1 Internal group meeting, Teagasc Food Bioscience , Fermoy 2023-12-08 - 2023-12-08
Lecture

Thomassen, Gunn Merethe Bjørge. (2023) Mattrygghet i hydroponisk dyrking av salat ved bruk av næring fra «human waste ». Agritech Cluster Fremtidige muligheter med bærekraftige matsystem , Digitalt 2023-02-14 -

2022

Lecture

Thomassen, Gunn Merethe Bjørge. (2022) Gjenstridige bakteriesamfunn i lakseslakteri - Betydning for mattryggheten. Lerøy Midt AS Bedriftsmøte , Hitra 2022-09-09 - 2022-09-09
Academic lecture

Lerfall, Jørgen; Hoel, Sunniva; Krych, Lukaz; Jakobsen, Anita Nordeng; Hannisdal, Atle; Duister, Ingrid Malien. (2022) Tracing Listeria monocytogenes in the production chain of Atlantic salmon (Salmo Salar L.) . FoodMicro2022 , Athen 2022-08-28 - 2022-08-31
Academic lecture

Lerfall, Jørgen; Hoel, Sunniva; Krych, Lukaz; Jakobsen, Anita Nordeng; Hannisdal, Atle; Duister, Ingrid Malien. (2022) Tracing Listeria monocytogenes in the production chain of Atlantic salmon (Salmo Salar L.) . Norges forskningsråd og FHF Havbruk22 , Bergen 2022-10-19 - 2022-10-21
Poster

Thomassen, Gunn Merethe Bjørge; Hjørungsnes, Martinus; Reiche, Thorben; Bringsli, Renate; Mehli, Lisbeth. (2022) Mixed Pseudomonas spp . biofilm aids Listeria monocytogenes to survive disinfection. International Committee on Food Microbiology and Hygiene Food Micro 2022 - Next generation challenges in Food Microbiology , Athens, Greece 2022-08-28 - 2022-08-31

2021

Poster

Thomassen, Gunn Merethe BjÃ¸rge; Krych, Lukas; Knøchel, Susanne; Mehli, Lisbeth. (2021) Efficient strain-level discrimination of the food pathogen Listeria monocytogenes. EFFoST 35th EFFoST International Conference , Lausann, Switzerland 2021-11-01 - 2021-11-04

2018

Poster

Thomassen, Gunn Merethe Bjørge; Mehli, Lisbeth. (2018) Microbial contamination of fish processing plants . Bits PILANI / Sintef REfood , Goa 2018-02-08 - 2018-02-09

2017

Poster

Thomassen, Gunn Merethe Bjørge; Lerfall, Jørgen; Jakobsen, Anita Nordeng; Mehli, Lisbeth. (2017) Profiling spoilage bacteria in lightly processed saithe (Pollachius virens). European Federation of Food Science and Technology (EFFoST) 31st EFFoST International Conference , Sitges 2017-11-13 - 2017-11-16

Språkvelger

Gunn Merethe Bjørge Thomassen