Katarina Bergström

Stockholm University / Marine Plastic Degradation

Advisor: Prof. Lars Eriksson

Katarina Bergström applies shotgun metagenomics to characterise the microbial communities colonising microplastic particles collected from confirmed Baltic Sea hot-spots — coastal bays and river outflows where microplastic concentrations exceed 10,000 particles per cubic metre. At Stockholm University's Department of Environmental Science and Analytical Chemistry, supervised by Prof. Lars Eriksson, she recovers metagenome-assembled genomes from 18 metagenomic datasets representing five polymer types (PET, PP, PS, LDPE, and PA) and four seasonal sampling windows. Thirty-one high-quality MAGs encode previously undescribed plastic oxidase and hydrolase gene families, and comparative genomics against the EnzymeMiner plastisphere database suggests three candidate PET hydrolases with active-site geometry distinct from the well-characterised IsPETase — implying independent evolutionary origin. Mineralisation bottle assays using ¹³C-labelled PET as sole carbon source confirm activity for two expressed enzymes at 20 °C — the Baltic's summer surface temperature. Her collaboration with the Swedish EPA's Baltic Sea monitoring programme provides both sample access and a direct stakeholder audience for clean-up biotechnology. Katarina's MICRO conference attendance and expressed interest in industrial biotechnology startup roles signal her entrepreneurial ambitions.