Current research activities include:
- Structure-function studies of biomass-converting enzymes and their accessory proteins and domains.
- Applied enzymology and bioprocessing for converting biomass to useful products.
- Biomass-degrading microbial communities; enzyme discovery.
- Gene expression systems, protein secretion and surface proteomics in lactic acid bacteria.
- Discovery and characterization of novel bacterial virulence factors.
- Development of nature-inspired novel catalysts
Some of this research is done in close collaboration with, or even led by, other groups at NMBU, particularly the Bioprocess Technology and Biorefining (BioRef) group headed by Professor Svein Horn and the MEMO group (Microbial Ecology and Meta-Omics) headed by Associate Professor Phil B. Pope. We also collaborate closely with Professor Morten Sørlie and researcher Åsmund Røhr Kjendseth in the Natural Product Chemistry and Organic Analysis group.
o Fundamental enzyme studies and enzyme development
o Applied enzymology
o Microbial communities and enzyme discovery
o Fermentation technologies
o LAB-based vaccines
o Bacterial virulence
o Catalyst development
We aim at combining high-level basic research with applied studies and innovation. We regularly collaborate with industry, but it is important for us to be scientifically fully independent and to base everything we do on a very strong basis in fundamental research.
Conversion of lignocellulosic material in Nature. The picture shows an artist impression of enzyme systems, including LPMOs and other redox enzymes, as well as non-enzymatic redox processes, involved in the degradation of lignocellulosic biomass. For more information, see here.
A large part of the group works on enzymes involved in biomass processing, in particular enzymes working on chitin, cellulose and various hemicelluloses.
One important group of enzymes are the lytic polysaccharide monooxygenases (LPMOs). The activity of these enzyme was first detected in our group in 2005 followed by a detailed description of their unique catalytic power in a landmark Science paper in 2010. The LPMOs are catching a lot of attention, since they are important for efficient bioprocessing of lignocellulosic biomass and since they are intriguing and abundant enzymes that likely have additional, hitherto undiscovered functions. While the catalytic function of LPMOs is only partly understood, it is clear that they carry out unique chemistry (see e.g. here). In 2019 one of our talented post-docs, Zarah Forsberg, received a grant from the Novo Nordisk Foundation to study multi-domain LPMOs.
Our latest project, which is an ERC-Synergy project called CUBE, aims at using the unique structure and catalytic power of LPMOs as inspiration for developing completely new enzyme-based and synthetic catalysts. To do so, we will collaborate with (bio)chemists specialized in catalysis in Oslo (Prof. Unni Olsbye), Turin (Prof. Silvia Bordiga) and Muelheim and der Ruhr (Prof. Serena DeBeer).
We have a large portfolio of enzyme projects, varying from fundamental structure-function studies to applied projects focusing on bioprocess development. The main scientific driver in these projects is to unravel how Nature manages to break down highly recalcitrant materials such as shrimp shells, wood and straw. The main applied driver is the need for developing green technologies (i.e., enzyme- and fermentation-based) for valorizing of non-edible biomass, such as forest residues and straw, as well as chitin-rich materials such as shrimp shells. On the applied side, we collaborate intensely with the Bioprocess Technology and Biorefining (BioRef) group led by Svein Horn. PEP member Aniko Varnai is a subproject leader in the Bio4Fuels project and plays a central role in coupling are fundamental enzyme work with applications.
We have been focusing quite a bit on efficient enzymatic degradation (or saccharificaton) of polysaccharides such as chitin and cellulose. Some more recent projects, have other targets. In the recently started FunEnzFibres project we study how we can use enzymes to produce high quality cellulose fibers. We also have projects aiming at the conversion of (hemi-)cellulose and chitin to shorter, soluble oligomers with a wide variety of (potential) function. Our research on chitin conversion has led to a spin-off company called BioCHOS, led by former group member Berit B. Aam.
While much of our work is centered around enzymes acting on biomass, we also do research in the fields of microbial ecology and molecular microbiology.
All the way since about 2000, we have been working on expressing useful proteins in lactic acid bacteria. In the past decade, this work has been focused on developing lactic acid bacteria as vaccine carriers, supported by two consecutive grants from the Norwegian GlobVac programme. This work is led by Ass. Professor Geir Mathiesen.
Expression of antigens in lactobacilli. Picture 1 shows various ways to anchor an antigen (yellow) to the cell membrane or cell wall of lactobacilli. Picture 2 shows bacterial cells visualized by indirect immunofluorescence microscopy; the green colour indicates the presence of the antigen on the bacterial surface. For more information, see e.g. here or here.
Driven by Phil Pope, who joined the group in 2009, we have developed research in microbial ecology, in particular on biomass-processing microbial communities. Today, Phil leads his own group, the MEMO group (Microbial Ecology and Meta-Omics), but there is still a lot of collaboration. In 2019, one of the young talented post-docs in the PEP group, Live H. Hagen, has been awarded an 8 mNOK Young Research Talent Researcher project from the Norwegian Research Council called "SeaCow: Promoting efficient, low emitting cows through manipulation of the rumen microbiome".
Interestingly, -omics data indicate that chitinases, the first enzymes ever studied in our group, and LPMOs, discovered by our group in 2005/2010, both play a role in bacterial virulence. Thus, these enzymes putatively present totally new virulence factors and their study may lead to unravelling novel aspects of bacterial pathogenicity. These topics are pursued by Deputy Group leader Professor Gustav Vaaje-Kolstad and his team, who today are focusing on revealing alternative functions of enzymes originally thought only to be involved in biomass processing.
We depend heavily on infrastructure, in particular a wide range of analytical instruments (HPLCs, Mass spectrometers) and small scale biorefining facilities. The PEP group is partner in the NorBioLab I & II and the Napi projects, which are national infrastructure projects funded by the Research Council of Norway. Thanks to years of hard work, external funding for these projects, and support from NMBU, we have highly up-to-date infrastructure for analytics, (meta-)proteomics and small scale biorefining. Our efforts and infrastructure in proteomics are directed by Morten Skaugen and Magnus Arntzen. Our participation in NorBioLab is directed by Vincent Eijsink, while the daily management of the biorefinery is done by Associate Professor Bjørge Westereng and co-workers in the Bioref group.
Part of the NMBU Biorefinery
Analytical equipment. HPLCs and mass spectrometers.
Analytical equipment. One of our ICS systems.
Part of the NMBU Biorefinery (three-phase separator and spray-drier).