Evaluation of cationic micropeptides derived from the innate immune system as inhibitors of marine biofouling

Abstract

A series of 13 short synthetic amphiphilic cationic micropeptides, derived from the antimicrobial iron-binding innate defence protein lactoferrin, have been evaluated for their capacity to inhibit the marine fouling process. The whole biofouling process was studied and microfouling organisms such as marine bacteria and microalgae were included as well as the macrofouling barnacle Balanus improvisus. In total 19 different marine fouling organisms (18 microfoulers and one macrofouler) were included and both the adhesion and growth of the microfoulers were investigated. It was shown that the majority of the peptides inhibited barnacle cyprid settlement via a reversible nontoxic mechanism, with IC₅₀ values as low as 0.5 μg ml⁻¹. Six peptides inhibited adhesion and growth of microorganisms. Two of these were particularly active against the microfoulers with MIC-values ranging between 0.01 and 1 μg ml⁻¹, which is comparable with the commercial reference antifoulant SeaNine.

Keywords:

• antifouling
• innate defence
• nontoxic
• peptides
• amphiphilic

Acknowledgements

UiT The Arctic University of Norway, Tromsø, Norway. Dr JS Svendsen and Dr R. Karstad are gratefully acknowledged for initial peptide generation and Dr L. Moodie is acknowledged for linguistic advice. H.P. and G.C. were supported by the Centre for Marine Chemical Ecology (http://www.cemace.science.gu.se) at the University of Gothenburg.

Conflict of interest disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grants from the Norwegian research council [ES508288] and UiT VINNOVA [2014-01435].