Optical Trapping for Investigating and Regulating Bacterial Biofilms

Biofilm formation is a bacterial survival response to hostile or suboptimal environmental conditions, driven by the secretion of a glue-like extracellular polymeric substance. In this work, the research team developed optical methods to study and regulate biofilms. Researchers examined how different light wavelengths influence biofilm development under a microscope and used optical tweezers to manipulate spatial structure and assess biofilm strength.

Experiments were conducted with bacteria including Bacillus subtilis in MSgg medium and Sinorhizobium meliloti in several biofilm-promoting media. Blue light (473 nm) induced cell rupture and disintegration of B. subtilis biofilms, while near-infrared light (820-830 nm) caused minimal damage and enabled optical structuring. Using tug-of-war optical tweezers, the team quantified how S. meliloti biofilm adhesion varies with nutrient composition. These findings contribute to understanding biofilm regulation with implications for health and bio-inspired materials.

About the presenter
Anna Bezryadina, Ph.D., is an associate professor in the Department of Physics and Astronomy at California State University, Northridge (CSUN), where she has been a faculty member since 2018. Her research focuses on optical trapping and manipulation, nonlinear optics in biological samples, optically controlled bacterial biofilms, and optical studies of microplastic and nanoplastic effects on biosystems. She earned her bachelor’s in physics from San Francisco State University (SFSU) and her doctorate in physics from the University of California, Santa Cruz (UCSC) in 2012.