MENY

Biofilms

“…biofilm cells are sad, sad organisms; imagine being born, raised and die attached to your parents! Umbilical cords prison…” -  Roald Kommedal (in a frustrated moment trying to avoid wall-growth)

Biofilms are microorganisms growing attached to surfaces, frequently embedded in a gel like extracellular polymer network of microbial origin (Bill Charaklis often cited definition from 1990). They form in almost any niche in nature, and are known to us as troublesome and sometimes, infectious stratums on industrial components, food, teeth, medical implants and mucoids. However, biofilms may also be used in beneficial bioprocesses. The ability of biofilms to host diverse and dense populations of active bacterial degraders may be used in environmental biotechnological applications such as wastewater treatment, off-gas treatment and bioremediation.

Our group focus on detachment of bacterial cells from biofilms, and synthesis and dynamics of the extracellular polymeric matrix (EPS), the connective tissue of biofilms. Our objective is to understand the mechanisms involved in biofilm detachment, the stoichiometry and rate of EPS synthesis and degradation, and propose descriptive mathematical models for the two processes. Methodologically we apply time lapse image analysis of biofilm flow cells to study biofilm formation and thickness control, combined with particle size analysis, flow cytometry and epi-fluorescence microscopy of the detached biofilm components. EPS analysis are carried our by liquid chromatography and ion chromatography for polymer size and composition analysis.

We also study depolymerisation (hydrolysis) of particulate and polymeric organic matter in natural biofilm systems. Our focus is on developing a mathematical model for degradation and growth on organic polymers in diffusion controlled micro-structures, including intermediate dynamics and identification and activity estimation of active extracellular depolymerising enzymes.

In addition to the more fundamental studies outlined above, we have initiated several programs in applied biofilm research. These include the application of cathodic protection of steel structures in marine structures exposed to biocorrosion by sulphate reducing bacteria, and micobioally enhanced oil recovery in cooperation with IRIS-Biomiljø.

Contact person: Roald Kommedal