EBCRC Project 4.21: Biofilm applications

Biofilms cause major problems in industrial and clinical settings, while standard antimicrobials and antibiotics are mostly inefficient against biofilms.

The Biofilm Applications Project aims at providing novel, specific solutions to biofilm issues based on fundamental knowledge of biofilm biology.

In 2005, the small signaling molecule nitric oxide (N-O) was discovered to play a role in the regulation of biofilm dispersal. Exposure to low, non-toxic concentrations of NO were found to change gene expression and induce the transition from a biofilm to a planktonic mode of growth in many species. Thus the use of NO, either via chemical compounds releasing NO in solution or via coatings that can be applied on surfaces and generate NO, may provide a low cost and environmentally safe solution to biofilm control.

The formation of biofilms that block filtration membranes affects a range of industries that rely on water purification, and it was determined as a priority area for initial demonstration and transfer of the NO technology to the industry. Our research identified two lead NO donors suitable for dispersing biofilms on reverse osmosis (RO) membranes, and that were found to increase the efficacy of a standard industrial disinfectant. In a recent pilot trial addition of nanomolar amounts of NO donor was found to increase the efficacy of a standard disinfectant by >1-log reduction in biofilms on RO membranes and reducing the amount of toxic chemicals by 3-fold.

The Biofilm Application project also investigated ways to improve antimicrobial formulations in the consumer product industry that are often expensive and applied at toxic concentrations with limited efficacy against biofilms. Several NO donors were tested and found to trigger dispersal of household biofilms, including biofilms formed in toilet bowl and washing machine model systems. Combination treatments resulted in 4-8 log reductions in biofilm forming bacteria.

Overall, the application of novel biofilm dispersal technology allows for reduced usage of toxic chemicals, reduced impact on the environment and improved efficacy of control measures against recalcitrant biofilms.

Image: Biofilm plus minus RO (Nic Barraud)

Project team

Key contact

(+61 2) 9385 2102
s.kjelleberg@unsw.edu.au