Investigating and Modeling Bacterial Growth in a Liquid Crystalline Environment

Abstract

Bacteria grow in complex environments. However, past studies investigate bacterial growth in simple aqueous solutions which do not accurately represent these complexities. One example of such a complex environment is Liquid Crystals (LCs). While research has focused on how LCs impact bacterial motility, knowledge of their influence on bacterial growth is unknown. This gives rise to the question: do LCs have any impact on the way bacteria grow, and if so, how, and why? To address this gap in knowledge we grow Escherichia coli cells in Disodium Cromoglycate solutions and show that, in the presence of a liquid crystalline environment, bacteria grow in single-cell diameter cables. We further demonstrate that this morphology is due to the properties of the liquid crystal given the coupling of the direction of cable growth and the inherent anisotropy of the LC. We also observe that, after a certain amount of time, these cables buckle. We are then able to characterize this phenomenon. These results suggest a pivotal role of liquid crystals in the growth morphology of bacteria, thus opening further research to extract new quantitative principles governing the morphogenesis of diverse forms of growing active matter.