Efficient Prevention of Marine Biofilm Formation Employing a Surface-Grafted Repellent Marine Peptide

Abstract

Creation of surfaces resistant to the formation of microbial biofilms via biomimicry has been heralded as a promising strategy to protect a range of different materials ranging from boat hulls to medical devices and surgical instruments. In our current study, we describe the successful transfer of a highly effective natural marine biofilm inhibitor to the 2D surface format. A series of cyclic peptides inspired by the natural equinatoxin II protein produced by Beadlet anemone (Actinia equine) have been evaluated for their ability to inhibit the formation of a mixed marine microbial consortium on polyamide reverse osmosis membranes. In solution, the peptides are shown to effectively inhibit settlement and biofilm formation in a nontoxic manner down to 1 nM concentrations. In addition, our study also illustrates how the peptides can be applied to disperse already established biofilms. Attachment of a hydrophobic palmitic acid tail generates a peptide suited for strong noncovalent surface interactions and allows the generation of stable noncovalent coatings. These adsorbed peptides remain attached to the surface at significant shear stress and also remain active, effectively preventing the biofilm formation over 24 h. Finally, the covalent attachment of the peptides to an acrylate surface was also evaluated and the prepared coatings display a remarkable ability to prevent surface colonization at surface loadings of 55 ng/cm2 over 48 h. The ability to retain the nontoxic antibiofilm activity, documented in solution, in the covalent 2D-format is unprecedented, and this natural peptide motif displays high potential in several material application areas.

Anti-Colonization Effect of Au Surfaces with Self-Assembled Molecular Monolayers Functionalized with Antimicrobial Peptides on S. epidermidis

“…The data unequivocally shows the presence of the specific peptides on the surface, and the surfaces are homogenous in nature. A drawback with the method is that it is not quantitative, making comparisons between specimens difficult [ 43 ]. However, the homogeneity within a sample is a good indication that we can consider that there are no gross differences in the surface density of the peptides between the different surfaces, but that the absolute surface density is an unknown factor.…”

Using Virtual AChE Homology Screening to Identify Small Molecules With the Ability to Inhibit Marine Biofouling

“…Settlement repelling compounds, in general, interfere with biochemical signal transduction pathways used by biofouling organisms to select a site to settle and initiate attachment and metamorphosis (Herzberg et al, 2021). The approach is intuitively attractive and there are many examples of natural allelochemicals active against one or a few biofouling taxa (Qian et al, 2009;Moodie et al, 2017a,b;Liu et al, 2020).…”

Creating New Antifoulants Using the Tools and Tactics of Medicinal Chemistry

“…Such examples include the microalgae-derived spirocyclic imine portimine (4) 27 and a series of cyclic peptides inspired by the equinatoxin II protein produced by the beadlet anemone (Actinia equine). 3 Given the structural complexities of such molecules, our studies typically employed SAR libraries populated with related natural products. We have also studied the antiparasitic macrocylic lactones ivermectin (generated from abamectin produced via fermentation of Streptomyces avermitilis) and abamectin.…”

“…59 The equinatoxin II mimetics are believed to function as signaling molecules that affect polysaccharide matrix production to generate highly effective nontoxic marine biofilm disruption. 3 Selectivity toward invertebrates for the avermectins is facilitated through motorneuron hyperpolarization via the stimulation of invertebrate-specific glutamate-gated chloride channels. 28 Several natural compounds explored are also effective inhibitors of the cholinesterases, which may present a conserved target for biofouling inhibition.…”

“…Our studies toward small-molecule lead identification and optimization have focused on antifouling bioactives from sessile marine organisms [barettin ( 1 ), the synoxazolidinones ( 2 ), and phidianidine A ( 3 )]; benthic microalgae [portimine ( 4 )]; and allelopathic terrestrial plant metabolites [batatasin III ( 5 ) and polygodial ( 6 )] (Figure ). In addition, we have studied larger compounds such as cyclic peptides from anemones and macrocyclic abamectin . Parent compounds have generally been generated via synthesis or isolated through bioassay-guided fractionation from organism extracts …”