The new CIIMAR study demonstrates that natural peptides produced by cyanobacteria are capable of replacing toxic biocides that dominate the market for anti-fouling paints used in the maritime industry. The use of these peptides as an active component brings direct benefits to the environment, the blue economy and marine biodiversity.
A consortium of researchers led by CIIMAR, in collaboration with the University of Lisbon and the University of Porto, has developed a new anti-fouling approach based on natural peptides from marine cyanobacteria. The proof of concept described in the study Engineered coatings containing cyclic peptides from cyanobacteria delay the development of a stable macrofouling community demonstrates its ability to replace conventional toxic coatings currently dominant in the global market.
Joana Almeida, researcher at CIIMAR's Bioinspired Ocean Interfaces group and leader of this study, explains that "the main innovation of this work lies in the use of natural peptides produced by cyanobacteria, which selectively interfere with the initial processes of biological colonisation, without harming non-target organisms or marine biodiversity." The result is a product capable of "effectively controlling marine biofouling without resorting to the continuous release of toxic biocides, paving the way for a new generation of environmentally responsible anti-fouling coatings."
The challenges of marine biofouling
Marine biofouling is a natural phenomenon that occurs when submerged surfaces, such as ship hulls, port infrastructure or aquaculture equipment, are colonised by bacteria, algae and invertebrates. This process represents one of the greatest operational and economic challenges for marine industries, particularly the shipbuilding industry, increasing ship maintenance costs, fuel consumption and emissions.
Currently, the dominant response to this problem is the use of paints that continuously release toxic biocides (copper and other metal compounds) to prevent fouling. Despite their effectiveness, these solutions have a high environmental cost, causing marine pollution, loss of biodiversity and degradation of ecosystems. Their action is so intense that some biocides, such as tributyltin (TBT), have already been banned by the European Union, which has required, through the Biocidal Products Regulation (EU 528/2012), the development of environmentally safe alternatives. Joana Almeida explains that "the transition to non-toxic anti-fouling solutions is inevitable given the European regulatory framework." The study, now published in the renowned scientific journal Trends in Biotechnology by the Cell group, presents an innovative natural-based solution that solves all the above challenges: "this transition is not only possible, but also technologically feasible," adds the CIIMAR researcher.
An effective and non-toxic alternative
During the experiments, coatings functionalised with bioactive peptides produced by a cyanobacterial strain included in CIIMAR's LEGE-CC collection proved to be particularly effective in interfering with biofilm formation and inhibiting the attachment of mussel larvae in the laboratory, thereby delaying the initial stages of biological colonisation in real marine environment conditions, a crucial aspect in the control of biofouling.
By interfering with the adhesion and sequential organisation processes of the initial encrusting communities, namely through the modulation of natural chemical signals that guide the adhesion of bacteria and other microorganisms, these compounds reduce the subsequent colonisation of macroalgae and invertebrates, without resorting to any chemical toxicity. This strategy is based on the ecological modulation of biofouling, inspired by chemical communication mechanisms that exist in the ocean. According to Joana Almeida, this "control of the initial stages of biofouling is crucial to prevent the development of the most problematic species. Our results show that it is possible to achieve this control by using the natural mechanisms of sequential colonisation to our advantage without releasing compounds that are harmful to the environment".
Equally important to note is that the study in question demonstrates that these peptides produced by marine cyanobacteria perform comparably, and in some respects superiorly, to a commercial biocide widely used in industry (Econea®). "By reducing the release of pollutants into the ocean, this technology has the potential to generate clear environmental benefits, but also direct economic gains for sectors such as maritime transport, aquaculture and coastal infrastructure," emphasises the CIIMAR researcher. The positive impacts extend to sectors such as fisheries, aquaculture and tourism, contributing to healthier oceans and a more sustainable blue economy.
From the laboratory to industry
Joana Almeida explains the potential of this study and its value as proof of concept, bringing the application of these peptides closer to industrial use: "This study goes beyond fundamental research: we have demonstrated the functional incorporation of the compounds into coatings and validated prototypes in real marine conditions, bringing the technology closer to industrial application." This advance represents a clear progression in the level of technological maturity, bringing a natural solution closer to future industrial application.
The technology is already at a promising pre-industrial stage. The next steps are to demonstrate long-term effectiveness in different marine environments and to optimise the production and incorporation processes of the compounds on a competitive industrial scale.
The results of this study also open up new perspectives for research and development of anti-fouling technologies inspired by nature, with clear benefits for the environment, industry and society, in line with the United Nations Sustainable Development Goals (SDGs), European requirements and positioning itself as a decisive step towards cleaner, more resilient and productive oceans.