Experimental and theoretical studies on the morphogenesis of bacterial biofilms

• Published in: Soft matter Vol. 13; no. 4; pp. 7389 - 7397
• Main Authors: Zhang, Cheng, Li, Bo, Tang, Jing-Ying, Wang, Xiao-Ling, Qin, Zhao, Feng, Xi-Qiao
• Format: Journal Article
• Language: English
• Published: England 18.10.2017
• Subjects: Bacillus subtilis - physiology; Biofilms - growth & development; Models, Biological; Morphogenesis; Surface Properties; Wettability
• ISSN: 1744-683X; 1744-6848
• DOI: 10.1039/c7sm01593c

Biofilm morphogenesis not only reflects the physiological state of bacteria but also serves as a strategy to sustain bacterial survival. In this paper, we take the Bacillus subtilis colony as a model system to explore the morphomechanics of growing biofilms confined in a defined geometry. We find that the growth-induced stresses may drive the occurrence of both surface wrinkling and interface delamination in the biofilm, leading to the formation of a labyrinthine network on its surface. The wrinkles are perpendicular to the boundary of the constraint region. The variation in the surface undulations is attributed to the spatial stress field, which is isotropic in the inner regime but anisotropic in the vicinity of the boundary. Our experiments show that the directional surface wrinkles can confer biofilms with anisotropic wetting properties. This study not only highlights the role of mechanics in sculpturing organisms within the morphogenetic context but also suggests a promising route toward desired surfaces at the interface between synthetic biology and materials sciences. Mechanics and geometry play a significant role in sculpturing bacterial biofilms within the morphogenetic context.