A new look at bubbles during biofilm inoculation reveals pronounced effects on growth and patterning

Abstract

Specially designed microfluidic bioflow cells were used to temporarily trap microbubbles during different inoculation stages of Pseudomonas sp. biofilms. Despite being eliminated many hours before biofilm appearance, templated growth could occur at former bubble positions. Bubble-templated growth was either continuous or in ring patterns, depending on the stage of inoculation when the bubbles were introduced. Templated biofilms were strongly enhanced in terms of their growth kinetics and structural homogeneity. High resolution confocal imaging showed two separate bubble-induced bacterial trapping modes, which were responsible for the altered biofilm development. It is concluded that static bubbles can be exploited for fundamental improvements to bioreactor performance, as well as open new avenues to study isolated bacteria and small colonies.

Key findings

• ▸Bubble-templated growth can occur at former bubble positions, even after bubbles are eliminated.
• ▸Two separate bubble-induced bacterial trapping modes were identified, affecting biofilm development.
• ▸Templated biofilms exhibit enhanced growth kinetics and structural homogeneity.

Keywords

Identifiers

DOI

10.1063/1.5005932

Journal

Biomicrofluidics

Year

2017