Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023

The thermophilic bacterium Rhodothermus marinus as a cell factory

Höfundar / Authors: Þórdís Kristjánsdóttir (1), Ólafur H. Friðjónsson (1), Björn Þór Aðalsteinsson (1, 2), Eva Nordberg Karlsson (3), Steinn Guðmundsson (2), Guðmundur Óli Hreggviðsson (1, 2)

Starfsvettvangur / Affiliations: 1. Matís 2. University of Iceland 3. Lund University

Kynnir / Presenter: Þórdís Kristjánsdóttir

Today, chemicals for industries are mainly produced from fossil fuel feedstocks, but sustainable and greener alternatives are needed. Biorefineries, where underexploited biomass such as seaweed and agricultural waste, is used as feedstock for microbial production of fuels and chemicals, is a feasible option. We believe that the bacterium Rhodothermus marinus is a good candidate for biorefineries as it: 1) is thermophilic, so it not only survives but thrives in the fluctuating and extreme temperatures often needed for this process (biomass treatment, polysaccharide solubility, reduce viscosity, minimize contamination risk, reduce costs of cooling, etc.), 2) can degrade and use many different polysaccharides, which are the major carbon sources in biomass, e.g. alginate and laminarin from brown seaweed, 3) natively produces industrially relevant chemicals, such as carotenoids and exopolysaccharides (EPS), and 4) can be genetically engineered with an efficient thermostable CRISPR-Cas9 system, making it possible to optimize strains to convert target biomass to target chemicals. Here, I will focus on our genetic engineering efforts for R. marinus, including 1) engineering the carotenoid biosynthetic pathway for production of lycopene and β-caroenoids, e.g. astaxanthin, 2) increasing cellulolytic activity by cloning heterologous cellulase genes in to the R. marinus genome, and 3) altering the EPS structure.