Utilization of woody biomass has emerged as a top priority to meet growing energy demands, address climate change, and support the change to a viable bio-economy. However, the natural resistance of woody biomass to chemical and biological deconstruction is a challenge that biorefineries have to overcome. In BioMim we have learned from nature how to utilise Scandinavian wood resources better.
Brown rot fungi play an important role during decay of conifer wood in boreal forests. Early in the brown rot decay process, extensive depolymerization of the wood cell wall occurs, causing the wood to rapidly lose strength. This causes challenges for wood in service but creates possibilities for developing technologies for biorefining. Through the BioMim project, we have acquired new insights into how brown rot fungi degrade wood and these are now being used to improve biorefining processes as well as wood protection.
BioMim turned out to be a highly timely project as it became clear during the course of the project that oxidative processes are involved in both enzymatic and non-enzymatic (= "Fenton") degradation of wood. Thus, the two systems are connected. So-called lytic polysaccharide monooxygenase (LPMO) enzymes play a crucial role. During the project there has been massive progress in understanding how LPMO enzymes work, how they interact with other redox enzymes, and how they interact with components of the non-enzymatic decay system. One key finding is that LPMO reactions may be fueled by hydrogen peroxide, and this are already being implemented at Borregaard. During the course of the project discoveries have also been made that change views on the possible role of the non-enzymatic first stage of wood decay and the components it involves. A proof-of-concept study in which we scaled up Fenton-based pretreatment of wood has been conducted and both the performance and the environmental impacts of this process were evaluated.
To understand more of wood degradation and wood protection systems, we have, for the first time, mapped the entire gene expression of a decay fungus in both untreated wood and wood modified by furfurylation from initial to advanced stages of decay. The results showed that the fungus starts a common decay process in the furfurylated wood, but proceeds at a slower pace and then levels out. These results are important for both the basic scientific understanding of ecology and carbon cycling in nature, and for our project partner Kebony.
BioMim has brought together a large network of partners within and outside Norway with complementary expertise. This novel network, with some excellent research groups, has been able to perform research in the very forefront of the field, leading to large scientific production and major progress. Importantly, this generation of knowledge, spanning from individual enzymes and chemical compounds to complete degradative systems, has already improved and will keep on improving processes and strategic development at both industrial partners, Borregaard and Kebony.
Utilization of woody (lignocellulosic) biomass has emerged as a top priority to meet growing energy demands, address climate change, and support forest economies. Research and technology development are critically needed to find cost-effective and sustainable solutions for the conversion of biomass. Extensive exploitation of lignocellulosic biomass as a feedstock for a variety of products is the key to develop a viable bio-economy. However, the natural resistance of lignocellulosic biomass to chemical and biological deconstruction is a challenge that biorefineries have to overcome.
We want to learn from nature how to do more with Scandinavian wood resources. The two primary wood species in Norway are Norway spruce (47%) and Scots pine (33%). Brown rot fungi occur primarily on conifer wood and in boreal forest. Early in the brown rot decay process, extensive depolymerization of the wood cell wall occurs, causing the wood to rapidly lose strength in comparison to the rate of wood metabolism. This causes challenges for wood in service but creates possibilities for developing technologies for biorefining.
Enzymes, which are a key tool for biomass depolymerization, cannot penetrate the intact wood cell wall. Brown-rot fungi possess unique mechanisms employing the use of small metabolites such as iron ions to selectively remove biomass components, thus creating much improved access to their enzymes. This mechanism can be exploited in biorefining, while on the other hand, it needs to be controlled to prevent fungal damage to wood in service.
Exploitation of this kind of chemistry in (industrial) biomass conversion has so far been of limited success, due to a lack of understanding of the reaction process and of the interplay between various enzyme types, metabolites and reaction conditions. Through the BioMim project, we will acquire new insights into how brown rot fungi degrade wood and these will be used to improve biorefining processes as well as wood protection.