Jens Kai Holm
M.Sc. (Biophysics)
Post Doc. (bio physics), Norwegian University of Science and Technology (NTNU) & ReaTech

I am currently employed in a post doc position at the Norwegian University of Science and Technology (NTNU), Department of Energy and Process Engineering in a project dealing with structure and binding properties of biomass pellets. The project is a collaboration between NTNU, ReAddit/ReaTech and the Department of Mechanical Engineering (MEK) at the Technical University of Denmark (DTU). The project is part of a larger collaboration with Energy E2 A/S, who is also co-financing the project. I am primarily situated at MEK, DTU and Readdit/ReaTech in Roskilde, Denmark.

The project is focused on the fundamental physical interactions between the constituent molecular species of biomass and co-added binders and additives. The potential problems between the optimal microscopic properties of biomass pellets and the large-scale production and processing are addressed in cooperation with collaborating research groups. By understanding the biophysical factors that determine the quality of biomass pellets, the production can be optimized with respect to handling and combustion properties.

I have a background in biophysics from the University of Copenhagen.

My PhD studies were carried out at the Department of Mathematics and Physics, University of Roskilde under the supervision of associate professor, PhD Dorthe Posselt. The PhD project concerns structural investigations of one of the most highly organized membrane systems found in biology, the thylakoid membrane system of green plants. The thylakoid membrane system organizes the photosynthetic machinery and thus serves as a flexible structural basis responsible for the regulation and optimization of the photosynthetic reactions.

I have mainly worked with small angle X-ray and neutron scattering combined with X-ray microscopy and circular dichroism spectroscopy. The combination of these techniques can provide structural knowledge about the interrelations between the organization of the membrane embedded protein complexes and the overall structure of the membrane system. Such information is of prime importance in order to understand the ability of plants to adapt to different environmental conditions.

The PhD project was carried out in close collaboration with professor Gyözö Garab, Institute of Plant Biology at the Biological Research Center in Szeged, Hungary. During a half year stay in professor Garab's lab, I have been working with isolation of thylakoid membranes and light-harvesting complexes and have been studying light-induced reversible structural changes in these systems with the aid of circular dichroism spectroscopy.

X-ray microscopy images of thylakoid membranes was obtained in collaboration with Associate Professor, PhD Joanna Abraham-Peskir from ISA, Institute for Storage Ring Facilities, University of Aarhus, Aarhus, Denmark.

Master thesis : PAC spectroscopy on two blue copper proteins (1999).

PhD thesis: Structure and structural flexibility of thylakoid membranes (2004).

Publications:

Jens K. Holm, Lars Hemmingsen, Luigi Bubacco, Benedetto Salvato, and Rogert Bauer. Interaction and coordination geometries for Ag(I) in the two metal sites of hemocyanin. Eur. J. Biochem. 2000 267: 1754-1760.

In preparation:

Structure and structural flexibility of thylakoid membranes - studied by small angle neutron scattering.

Jens Kai Holm1, László Kovács2, Eszter Rétfalvi3, László Rosta3, Gyözö Garab2 and Dorthe Posselt1

1IMFUFA (Dept. of Mathematics and Physics), Roskilde University, P.O.Box 260, DK-4000 Roskilde, Denmark.

2Biological Research Center, Hungarian Academy of Sciences, P.O.Box 521, H-6701 Szeged, Hungary.

3Budapest Neutron Centre and Research Institute for Solid State Physics and Optics, P.O.Box 49, H-1525 Budapest, Hungary

Structure and structural flexibility of thylakoid membranes - studied by small angle x-ray scattering.

Jens Kai Holm1, Gyözö Garab2 and Dorthe Posselt1

1IMFUFA (Dept. of Mathematics and Physics), Roskilde University, P.O.Box 260, DK-4000 Roskilde, Denmark.

2Biological Research Center, Hungarian Academy of Sciences, P.O.Box 521, H-6701 Szeged, Hungary.

Reversible structural changes in the aggregation state of the main chlorophyll a/b light harvesting pigment-protein complex of green plants.

Jens Kai Holm1,2, Zsuszanna Várkonyi1, László Kovács1, Dorthe Posselt2 and Gyözö Garab1

1Biological Research Center, Hungarian Academy of Sciences, P.O.Box 521, H-6701 Szeged, Hungary.

2IMFUFA (Dept. of Mathematics and Physics), Roskilde University, P.O.Box 260, DK-4000 Roskilde, Denmark.

Back