Eradication of Biofilms in Metal Working Fluids

Montana State University, Bozeman MT

Investigators

Abstract

Metal working fluids are applied in many manufacturing processes to ensure reduced tool wear and improved work piece quality. Worldwide, more than half a billion gallons of metal working fluids are consumed annually. Microbial contamination is a significant factor in the degradation of these fluids, causing biofouling and corrosion of equipment, imperilment of product quality, and posing occupational safety risks. Once metal working fluids are microbially contaminated, removing bacteria is a difficult task. Residual bacteria can quickly repopulate, even after meticulous cleaning and recharge procedures. Microbial biofilms within the inaccessible regions of a working fluid system are likely responsible for the rapid post-cleaning repopulation. Biofilms are attached microbial communities whose function depends on complex social interactions. Quorum sensing provides the means for biofilm cells to communicate and collectively control group behavior. This award supports fundamental research on quorum sensing inhibition strategies to reduce/eliminate biofilm formation. Research results can help to increase the sustainability of metal working fluids, reduce waste, and help limit occupational exposure to potentially pathogenic bacteria inhabiting the fluids. This is a very large concern in manufacturing, with applications in automotive, aerospace, medical products and defense industries, and therefore directly and positively impacts American economic welfare and national security. The award includes funding of outreach activities, especially for attraction of Native American students into engineering. A three-year study at the Center for Biofilm Engineering at Montana State University will be performed to improve metal working fluid management using an eco-friendly alternative to remove biofilms residing within metal working fluid circulation systems. Using a two-phase approach, economically feasible agents will be screened for their ability to effectively reduce/eliminate biofilm forming organisms in metal working fluids. Phase one will involve screening a matrix of chemical/synthetic quorum sensing inhibition agents, bacterial pigments, and bioengineered enzymes for their ability to eradicate biofilm in microplate assays. The most efficacious agents would be optimized to remove biofilm, both singly and in combination with standard biocide treatments. Phase two would scale up experiments on selected agents to determine suppression/removal of biofilm in MWF circulation systems including CDC bioreactors and a fully functional, autoclavable model of a CNC milling machine designed and built by a student capstone team. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.