# Surface Interactions between an Eco-Friendly Antifouling Agent and Pseudoalteromonas tunicata Membrane

## TL;DR

This study explores how an eco-friendly antifouling compound interacts with bacterial membranes to prevent biofilm formation.

## Contribution

The novel contribution is the direct investigation of a polyphenolic molecule's interaction with bacterial membrane models and P. tunicata.

## Key findings

- GBA26 interacts with lipid monolayers, influenced by phospholipid composition.
- GBA26 disrupts P. tunicata membranes and reduces bacterial culturability without causing ROS formation.

## Abstract

In this work, we investigated the interfacial chemistry
of our
recently developed antifouling polyphenolic small molecule (GBA26)
directly with bacterial membrane models and the marine bacterium Pseudoalteromonas tunicata. Different Langmuir lipid monolayer
models were constructed to mimic the interface of bacterial membranes.
Surface pressure–area isotherms showed that GBA26 interacted
with assembled lipid monolayers, and this interaction was influenced
by the phospholipid composition. GBA26 was also able to interact with
monolayers of lipopolysaccharide (LPS) extracted from P. tunicata. The morphology of the monolayer was also analyzed using Brewster
angle microscopy (BAM), showing that GBA26 reduced lipid domains'
condensation levels. Flow cytometry data indicated that GBA26 disrupts
cell membranes and reduces the metabolic activity of P. tunicata, without inducing ROS formation. Furthermore, GBA26 significantly
decreased bacterial culturability. Altogether, these results shed
light on its antibiofilm mechanism against this marine bacterium.