Characterisation of spin coated engineered Escherichia coli biofilms using atomic force microscopy

Area of Science:

• Microbiology
• Biotechnology
• Materials Science

Background:

• Biofilms offer potential as robust biocatalysts due to their resilience.
• Assessing biofilm surface properties and adhesion strength is critical for their use in bioreactors.

Purpose of the Study:

• To characterize the surface properties and adhesive strength of Escherichia coli biofilms under growth conditions.
• To evaluate the suitability of spin-coating for generating robust biofilms for biocatalysis.

Main Methods:

• Atomic force microscopy (AFM) was used to study biofilm topography and tip-cell interaction forces.
• Escherichia coli biofilms were grown using a novel spin-coating method on a poly-l-lysine coated glass substrate.
• Biofilm maturation was monitored over 10 days at 30°C, with electron microscopy used to observe extracellular polymer substance (EPS).

Main Results:

• Adhesion force between the AFM tip and biofilm surface increased significantly from 0.8 nN to 40 nN within 3 days.
• Increased adhesion is attributed to the production of extracellular polymer substance (EPS) during biofilm maturation.
• Spin-coated biofilms exhibited stronger surface adhesion compared to conventionally grown biofilms.

Conclusions:

• Spin-coating is a viable method for producing biofilms with enhanced adhesive properties for potential biocatalyst applications.
• Understanding biofilm adhesion dynamics is key to optimizing their performance in bioreactor environments.