Rotaru Lab

University of Southern Denmark

Status: completed (2015-2018)

Harnessing microbial metabolism for the production of useful chemicals.
Novo Nordisk Foundation awarded 2.5 mil. DKK to engineer microorganisms for the production of valuable chemicals. The project will be carried out primarily at SDU with a short stay at UMass, and in collaboration with AU.

Project summary

The project is about recuperating excess renewable electricity as useful chemical commodities, using microorganisms as catalysts. We intend to generate valuable chemicals like biofuels, animal feed, and plastic precursors using biogas as CO2 source for the microorganisms while providing electrons from renewable-energy-powered electrodes. The project is grounded on recent developments in microbial electrosynthesis and intends to find strategies for green production of useful chemicals from renewable resources, hereafter touching upon three major legs of the Novo Nordisk call: the use of biological tools for making valuable products, improvement of the production potential in microorganisms, improvement of raw/renewable material utilization.

Microbial electrosynthesis from biogas will be studied in Clostridium ljungdahlii, a versatile acetogenic bacterium. Chemical production in Clostridium will be improved using genetic engineering, nano engineering and removal of inhibitory by-products with the help of microbial partners. Furthermore, C. ljungdahlii will be metabolically engineered to produce desired value-added chemicals by implementing new metabolic pathways.

The novelty of our approach lies in nano- and genetic- engineering of Clostridium cell surfaces to increase electron transfer from electrodes to microorganisms; and the use of synthetic consortia to sway electron flow towards the production of desired chemicals. This is the first time these methods will be used to improve conversion of biogas to valuable chemicals.

The proposed work aims to synergize biogas upgrading and biogas conversion to valuable commodities, in order to attain the chemical power plants of the future, fueled by renewable energy sources and waste products.

Publications fully or partially funded by the NNF grant

  1. Walker et al., 2020. The ISME Journal
  2. Rotaru et al., 2019. Limnetica 38(1): 21-40
  3. Holmes et al., 2018. Front. Microbiol. 9: 3109
  4. Ueki et al., 2018. mBio 9(4)
  5. Holmes et al. 2018. Microbial Ecology: 1-8
  6. Rotaru and Shrestha. 2016. Frontiers in Microbiology 7:662
  7. Rotaru and Thamdrup 2016. Science 351: 658
MSc thesis:

Jensen D. 2018. M.Eng. Producing PHBs from renewable sources. (AU/SDU)