Title Morphologies and phenotypes in Bacillus subtilis biofilms
Author Xiaoling Wang1,2*, Shuo Meng1, and Jingshi Han1
Address 1School of Mechanical Engineering, University of Science and Technology, Beijing, P. R. China, 2John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
Bibliography Journal of Microbiology, 55(8),619–627, 2017,
DOI 10.1007/s12275-017-7041-z
Key Words Bacillus subtilis, biofilm, fluorescence, morphology, phenotype
Abstract In this study, we explored Bacillus subtilis biofilm growth under various conditions such as the use of substrates with different stiffnesses and nutrient levels using a well-developed optical imaging technique to spatially and temporally track biofilm growth. We also developed a quantitative method to characterize B. subtilis biofilm morphologies under various growth conditions. To determine biofilm rim irregularities, we used the dimensionless P2A ratio, defined as P2/4πA, where P is the perimeter and A is the area of the biofilm. To estimate biofilm thickness from transmission images, we developed a calibration procedure based on Beer- Lambert’s law and cross sectioning. Furthermore, to determine the distributions of different B. subtilis cell phenotypes during biofilm growth, we used a triple-fluorescence-labeled B. subtilis strain that expressed motility, matrix production, and sporulation. Based on this work, we are able to tune biofilm growth by changing its growing environment.