Microbiology, Virology, Host-pathogen interactions, Molecular biology and biotechnology
Main research activities
My recent research has mainly focused on studying quorum sensing (QS) in the marine, pathogenic bacteria Aliivibiro salmonicida. QS is a cell-to-cell signaling system that enables bacterial populations to collectively regulate gene expression in response to cell density and thus coordinate group behaviors. Our study shows that A. salmonicida produces eight different QS signal molecules (N-acyl-homoserine lactones) to regulate activities such as biofilm formation, colony morphology, motility, and virulence amongst others. A. salmonicida causes disease in the Atlantic salmon only during winter seasons when the sea temperature is low, and our studies show that temperature is an important environmental factor for QS in this bacteria.
The most recent project I have focused on explores the potential of using Arctic, marine bacteria as bioplastics producers. When grow in an environment with nutrient imbalance, many bacteria can store carbon as polyhydroxyalkonates (PHA), a fully biodegradable biopolyester. These carbon storages are visible as large granules in the cytoplasm. Based on the presence of pha synthase genes we have selected and screened different marine proteobacteria for their ability to produce PHA. Several promising candidates have been identified and shown to produce intracellular PHA granules.
My MSc and PhD work was within the field of virology where I studied orthopoxviruses. The aims were to study distribution of orthopoxviruses within the Norwegian fauna, to characterize cowpox viruses isolated from Fennoscandinavia and to study risks associated with using genetically modified orthopoxviruses as vaccine vectors.
MarPlast (2017-2020) Marine microorganisms for bioplastics production (WP-leader)
MarVal From unexploited marine biomass to high value products (Researcher)
Publications not listed in CRIStin
Hansen H, Okeke MI, Nilssen Ø, Traavik T (2004). Recombinant viruses obtained from co-infection in vitro with a live vaccinia-vectored influenza vaccine and a naturally occurring cowpox virus display different plaque phenotypes and loss of the transgene. Vaccine 23(4):499-506.
Hansen H, Sandvik T, Tryland M, Olsvik Ø, Traavik T (1999). Comparison of thymidine kinase and A-type inclusion protein gene sequences from Norwegian and Swedish cowpox virus isolates. APMIS 107(7):667-75.
Sandvik T, Tryland M, Hansen H, Mehl R, Moens U, Olsvik Ø, Traavik T (1998). Naturally occurring orthopoxviruses: potential for recombination with vaccine vectors. J Clin Microbiol. 36(9):2542-7.
Tryland M, Sandvik T, Hansen H, Haukenes G, Holtet L, Bennett M, Mehl R, Moens U, Olsvik Ø, Traavik T (1998). Characteristics of four cowpox virus isolates from Norway and Sweden. APMIS 106(6):623-35.