Extracellular polymeric substances protect Escherichia coli from organic solvents

Abstract

The roles and functions of extracellular polymeric substances (EPS) have been intensively studied. Besides the significance of EPS in microbial multi-cellular structure formation, the interaction between EPS and external stressors was also investigated. However, seldom research studied how EPS response to organic solvents, a general type of chemicals in industry and potential pollutants in environments. In the present study, we found that EPS can response to n-butanol (n-BuOH) stress via excess secretion and varied composition, and EPS protect Escherichia coli from the n-BuOH stress. The extracellular proteins in EPS played a significant role in the protective effects via contributing to the surface hydrophobicity putatively by changing the secondary structure. We believe these findings would enable us to understand the functions of EPS in bacterial physiological activities better and benefit the EPS-related bioprocesses. This study would also provide us alternatives to utilize microorganisms with EPS excretion routine.