Antifouling potential of Subtilisin A immobilized onto maleic anhydride copolymer thin films

Abstract

The proteinaceous nature of the adhesives used by most fouling organisms to attach to surfaces suggests that coatings incorporating proteolytic enzymes may provide a technology for the control of biofouling. In the present article, the antifouling (AF) and fouling release potential of model coatings incorporating the surface-immobilized protease, Subtilisin A, have been investigated. The enzyme was covalently attached to maleic anhydride copolymer thin films; the characteristics of the bioactive coatings obtained were adjusted through variation of the type of copolymer and the concentration of the enzyme solution used for immobilization. The bioactive coatings were tested for their effect on the settlement and adhesion strength of two major fouling species: the green alga Ulva linza and the diatom Navicula perminuta. The results show that the immobilized enzyme effectively reduced the settlement and adhesion strength of zoospores of Ulva and the adhesion strength of Navicula cells. The AF efficacy of the bioactive coatings increased with increasing enzyme surface concentration and activity, and was found to be superior to the equivalent amount of enzyme in solution. The results provide a rigorous analysis of one approach to the use of immobilized proteases to reduce the adhesion of marine fouling organisms and are of interest to those investigating enzyme-containing coating technologies for practical biofouling control.

Immobilized enzymes affect biofilm formation

“…Our studies showed that the adhesion strength of Ulva linza spores and Navicula perminuta cells decreased in the presence of the active enzyme, and that the effect of the enzyme was significantly enhanced when the enzyme was surfaceconfined (Tasso et al 2009b), revealing the important role of enzyme location at the surface-fouler interface on antifouling efficacy.…”

“…Recently, we have developed a well-defined model system to investigate the influence of immobilized subtilisin A on the adhesion of major marine foulers (Tasso et al 2009a;Tasso et al 2009b). Our studies showed that the adhesion strength of Ulva linza spores and Navicula perminuta cells decreased in the presence of the active enzyme, and that the effect of the enzyme was significantly enhanced when the enzyme was surfaceconfined (Tasso et al 2009b), revealing the important role of enzyme location at the surface-fouler interface on antifouling efficacy.…”

“…The immobilization and characterization of subtilisin A onto MA copolymer films are described in detail elsewhere (Tasso et al 2009a;2009b).…”

“…polymer coatings not containing enzyme), and with control samples consisting of PEMA copolymer films containing heatdenatured enzyme. The heat-denatured subtilisin A controls were prepared by heating immobilized subtilisin A layers to 120 °C for 45 min as described in (Tasso et al 2009b). Inactivated cellulase layers were prepared by autoclaving correspondent active layers for 20 min at 120 °C.…”

Trends in the development of environmentally friendly fouling-resistant marine coatings

“…For example, protein-degrading enzymes (serine proteases) have been shown to be effective in reducing settlement and adhesion strength of a range of fouling organisms, algal spores, diatoms and barnacle cyprids 71 , due to dissolution of adhesive 72,73 . However, the challenge for enzyme technology will be to achieve controlled release and stability of enzymes when incorporated into a coating 74,75 . In some cases, the novel coatings we have discussed are real candidates for practical application after further development work.…”