Title：Antifouling mechanism of natural product-based coatings investigated by digital holographic microscopy

Abstract: Using natural product-based antifouling coatings has proven to be an effective strategy to combat biofoul-ing. However, their antifouling mechanisms are still unclear. In this study, the antifouling mechanism ofnatural product-based coatings consisting of bio-sourced poly(lactic acid)-based polyurethane and eco-friendly antifoulant (butenolide) derived from marine bacteria was revealed by observing 3D bacterialmotions utilizing a 3D tracking technique-digital holographic microscopy (DHM). As butenolide contentincreases, the density of planktonic marine bacteria (Pseudomonas sp.) near the surface decreases and thusleads to a reduced adhesion, indicating that butenolide elicits the adaptive response of Pseudomonas sp.to escape from the surface. Meanwhile, among these remained cells, an increased percentage is found toundergo subdiffusive motions compared with the case of smaller dose of butenolide. Further experimentsshow that butenolide can accelerate their swimming velocity and reduce flick frequency. Antibacterialassay confirms that butenolide-based coating shows high efficacy of antifouling performance againstPseudomonas sp. but without killing them like 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT).

文章链接：https://doi.org/10.1016/j.jmst.2021.02.006