Biografi

Jeg er utdannet bioteknolog fra det Tekniske Universitetet i Braunschweig (Tyskland) og har en doktorgrad på bioprosessteknologi fra Leibniz Universitetet i Hannover (Tyskland). Min hovedinteresse er utviklingen av bioteknologiske prosesser innen bioenergi og næringsstoffgjenvinning. I mine doktorgradsstudier har jeg optimalisert produksjonsprosesser for sekundære metabolitter i marine bakterier og i min tid på Uppsala Universitetet (Sverige) utviklet jeg molekylære verktøy for en syntetisk biologisk tilnærming innen cyanobakterier. Siden jeg kom til NIBIO i 2012 har jeg jobbet med utviklingen av fotobioreaktorsystemer og bioprosesser med grønne mikroalger. Idag er mitt primære fokus på resirkulering av næringsstoffer fra avløpsvann og industrielle sidestrømmer innen en sirkulær bioøkonomi.

Nøkkelord som beskriver mine vitenskapelige interesser er:

  • Fototrofiske mikroorgansimer: Grøne mikroalger og cyanobakterier
  • Utvikling og konstruksjon av (foto)bioreaktorsystemer
  • Optimalisering av bioprosesser
  • Gjenvinning av næringsstoffer
  • Behandling av avløpsvann og industrielle sidestrømmer
  • Biodrivstoff, bioplast, biogjødsel, biostimulering
  • Sirkulær bioøkonomi

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Sammendrag

Several species of microalgae and phototrophic bacteria are able to produce hydrogen under certain conditions. A range of different photobioreactor systems have been used by different research groups for lab-scale hydrogen production experiments, and some few attempts have been made to upscale the hydrogen production process. Even though a photobioreactor system for hydrogen production does require special construction properties (e.g., hydrogen tight, mixing by other means than bubbling with air), only very few attempts have been made to design photobioreactors specifically for the purpose of hydrogen production. We have constructed a flat panel photobioreactor system that can be used in two modes: either for the cultivation of phototrophic microorganisms (upright and bubbling) or for the production of hydrogen or other anaerobic products (mixing by “rocking motion”). Special emphasis has been taken to avoid any hydrogen leakages, both by means of constructional and material choices. The flat plate photobioreactor system is controlled by a custom-built control system that can log and control temperature, pH, and optical density and additionally log the amount of produced gas and dissolved oxygen concentration. This paper summarizes the status in the field of photobioreactors for hydrogen production and describes in detail the design and construction of a purpose-built flat panel photobioreactor system, optimized for hydrogen production in terms of structural functionality, durability, performance, and selection of materials. The motivations for the choices made during the design process and advantages/disadvantages of previous designs are discussed.

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Sammendrag

Cyanobacteria are suitable for sustainable, solar-powered biotechnological applications. Synthetic biology connects biology with computational design and an engineering perspective, but requires efficient tools and information about the function of biological parts and systems. To enable the development of cyanobacterial Synthetic Biology, several molecular tools were developed and characterized: (i) a broad-host-range BioBrick shuttle vector, pPMQAK1, was constructed and confirmed to replicate in Escherichia coli and three different cyanobacterial strains. (ii) The fluorescent proteins Cerulean, GFPmut3B and EYFP have been demonstrated to work as reporter proteins in cyanobacteria, in spite of the strong background of photosynthetic pigments. (iii) Several promoters, like P(rnpB) and variants of P(rbcL), and a version of the promoter P(trc) with two operators for enhanced repression, were developed and characterized in Synechocystis sp. strain PCC6803. (iv) It was shown that a system for targeted protein degradation, which is needed to enable dynamic expression studies, is working in Synechocystis sp. strain PCC6803. The pPMQAK1 shuttle vector allows the use of the growing numbers of BioBrick parts in many prokaryotes, and the other tools herein implemented facilitate the development of new parts and systems in cyanobacteria.

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Sammendrag

Hydrogen production through biological routes is promising because they are environmentally friendly. Hydrogen production through biophotolysis or photofermentation is usually a two stage process. In the first stage CO2 is utilized for biomass production which is followed by hydrogen production in the second stage in anaerobic/sulfur deprived conditions in the next stage. The major challenges confronting the large scale production of biomass/hydrogen are limited not only on the performance of the photo bioreactors in which light penetration in dense cultures is a major bottleneck but also on the microbiology, biochemistry and molecular biology of the organisms. Other dependable factors include area/ volume (A/V) ratio, mode of agitation, temperature and gas exchange. Photobioreactors of different geometries are reported for biohydrogen production-Tubular, Flat plate, Fermentor type etc. Every reactor has its own advantages and disadvantages. No reactor is ideal for this purpose. Airlift, helical tubular and flat plate reactors are found most suitable with respect to biomass production. These bioreactors may be employed for hydrogen production with necessary modifications to overcome the existing bottlenecks like gas hold up, oxygen toxicity and improved agitation system. This review article attempts to focus on existing photobioreactors with respect to biomass generation and hydrogen production and the steps taken to improve its performance through engineering innovation that definitely help in the future construction of photobioreactors.