Review on Molecular Mechanisms of Antifouling Compounds: An Update since 2012

Abstract

Better understanding of the mechanisms of antifouling compounds is recognized to be of high value in establishing sensitive biomarkers, allowing the targeted optimization of antifouling compounds and guaranteeing environmental safety. Despite vigorous efforts to find new antifouling compounds, information about the mechanisms of antifouling is still scarce. This review summarizes the progress into understanding the molecular mechanisms underlying antifouling activity since 2012. Non-toxic mechanisms aimed at specific targets, including inhibitors of transmembrane transport, quorum sensing inhibitors, neurotransmission blockers, adhesive production/release inhibitors and enzyme/protein inhibitors, are put forward for natural antifouling products or shelf-stable chemicals. Several molecular targets show good potential for use as biomarkers in future mechanistic screening, such as acetylcholine esterase for neurotransmission, phenoloxidase/tyrosinase for the formation of adhesive plaques, N-acyl homoserine lactone for quorum sensing and intracellular Ca2+ levels as second messenger. The studies on overall responses to challenges by antifoulants can be categorized as general targets, including protein expression/metabolic activity regulators, oxidative stress inducers, neurotransmission blockers, surface modifiers, biofilm inhibitors, adhesive production/release inhibitors and toxic killing. Given the current situation and the knowledge gaps regarding the development of alternative antifoulants, a basic workflow is proposed that covers the indispensable steps, including preliminary mechanism- or bioassay-guided screening, evaluation of environmental risks, field antifouling performance, clarification of antifouling mechanisms and the establishment of sensitive biomarkers, which are combined to construct a positive feedback loop.

Love at First Taste: Induction of Larval Settlement by Marine Microbes

“…Subsequent reviews focused either on biofouling and commercially important species [11,25] or particular processes, like quorum sensing and its inhibition [16,22]. Molecular mechanisms of larval settlement and inhibition were recently reviewed as well [52][53][54][55]. The development of novel omic-methods (metagenomics, metabolomics, transcriptomics, proteomics) resulted in many new findings in larval settlement and attachment.…”

Structure-Antifouling Activity Relationship and Molecular Targets of Bio-Inspired(thio)xanthones

“…More recently, a xanthone isolated from a marine-derived fungus Aspergillus terreus was also found to be a potent antifoulant [15]. Nonetheless, little information on structure-antifouling activity relationship and ultimately on the mechanism of action of polyketide-related compounds, namely xanthones, is available [16,17].…”

Electrochemical Preparation of Synergistic Nanoantimicrobials

“…Previous studies on nanomaterials stabilized by quaternary alkyl ammonium salts demonstrated a controlled copper release when they are put in contact with aqueous solutions, thus exerting a marked inhibiting action against the growth of various copper-sensitive microorganisms [2,19,27,[34][35][36]. In this work, a systematic evaluation of copper release properties in aqueous solutions of composite films stabilized by BAC disinfectant agent was performed as a function of the CuNPs loading.…”