Novel Anti-fouling Strategies of Live and Dead Soft Corals (Sarcophyton trocheliophorum): Combined Physical and Chemical Mechanisms

At present, biomimetic antifouling research objects are mostly concentrated on the fast-moving marine organism, but the anti-fouling effect of the low-speed or static marine equipment is not obvious. This paper describes the anti-fouling mechanism of soft coral (Sarcophyton trocheliophorum), including the physical defense mechanism and the bactericidal ability of mucus and coral powder. As a sessile organisms, soft coral lacks escape mechanism. Therefore, the study on its antibacterial strategy is significant because it can provide theoretical guidance for static antifouling. Results showed that the live soft coral would molt in unfriendly environment, and the secreted mucus could defend themselves against fouling microorganism. Then, Liquid Chromatography-Mass Spectrometry (LC-MS) analysis was conducted to identify the bioactive compounds of the coral powder and mucus. Results revealed that both powder and mucus contained a wide variety of toxic components, which had bactericidal effects. Moreover, at the same concentration, the inhibitory effect of the main components on Gram-negative bacteria was stronger than that on positive bacteria. These findings enhance the understanding about the antifouling mechanism of soft coral and provide new ideas for design and prepare novel antifouling strategy to combat biofouling under static condition.