Researchers Control Biofilm Formation Using Optical Traps
Published:07 Mar.2024    Source:Optica
Biofilms -- slimy layers formed when bacteria stick together on a surface -- allow bacteria to shield themselves from extreme environments and even evade antibiotics. In a new study, researchers showed that laser light in the form of optical traps can be used to control biofilm formation. The findings could allow scientists to harness these microbial layers for various bioengineering applications.
The researchers experimented with Bacillus subtilis, a non-pathogenic bacterium that naturally forms biofilms. They used a low-nutrient environment that is hostile to B. subtilis to prompt the bacteria to form a biofilm. They found that using a laser emitting at a wavelength of 820 nm to 830 nm enabled prolonged optical trapping of biofilm clusters while minimizing significant photodamage. However, using a laser at 473 nm -- a wavelength highly absorbed by the bacteria -- caused the cells to rupture and the biofilm clusters to disintegrate. When the researchers studied bacteria dynamics and biofilm formation using optical tweezers at 820 nm wavelength for an hour, they discovered that bacterial clusters aggregated near optically trapped clusters, adhered to the surface and started to form a microcolony.

Overall, the experiments revealed some flexibility in the exact growth conditions, sizes of clusters and wavelengths necessary for manipulating the biofilms. The researchers say that it might also be possible to use their methodology with other types of biofilm-forming microorganisms.< style="display:none" href="">