Environmental Science and Pollution Research

, Volume 12, Issue 5, pp 278–284 | Cite as

Assessment of Antifouling Effectiveness of two Natural Product Antifoulants by Attachment Study with Freshwater Bacteria (7 pp)

  • Qingwei Xu
  • Carlos Barrios
  • Teresa Cutright
  • Bi-min Zhang Newby



Goal, Scope, Background. The traditional solution for keeping unwanted organisms from attaching to submerged surfaces is to apply anti-fouling coatings. The most common antifoulant was tributyltin (TBT). TBT systems were highly effective but were also toxic to non-target organisms. The use of the TBT based coatings will be completely banned by January 1, 2008. Therefore, there is an urgent need to seek out suitable non-toxic alternatives.


The aim of this work was to evaluate the effectiveness of capsaicin and zosteric acid as natural product antifoulants (NPAs) in deterring bacterial attachment. Two fresh water bacteria systems Pseudomonas putida (Pp) and bacteria isolated from Lake Erie (LE) were used to assess the attachment when the NPAs dispersed in the water. Effectiveness was ascertained based on the decrease in microbial attachment, limited toxicity, and minimum alteration of the coatings properties.

Results and Discussion

A significant inhibition of bacteria attachment was achieved when aqueous capsaicin concentration was increased from 0 to 40 mg/L. For instance, after 14 days the LE system depicted 93.5% and 98.5% less biofilm coverage for 20 mg/L and 40 mg/L capsaicin, respectively when compared to systems without NPA. Biofilm coverage was reduced by 92.5% and 98.2%, respectively with 50 mg/L and 500 mg/L zosteric acid.


Both capsaicin and zosteric acid was effective at preventing bacteria attachment. As the NPA aqueous concentration increased, biofilm formation decreased. Evaluating changes in aqueous pH, conductivity, dissolved oxygen, aqueous microbial population and biofilm formation suggested that the primary antifoulant mechanism of these two NPAs was to block the bacteria's active sites versus posing a lethal level.

Recommendation and Perspective

From the attachment study, zosteric acid appeared to be more effective in preventing bacterial attachment when the NPAs were dispersed in the aqueous environment. For practical applications, the antifoulant needs to be incorporated into a coating and have a slow release rate. Thus the ability to successfully incorporate zosteric acid into a coating, without deterring bacterial attachment, needs to be investigated.

natural product antifoulants (NPAs) capsaicin biofilms antifouling mechanisms antifoulants tributyltin (TBT) zosteric acid 


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Copyright information

© Ecomed 2005

Authors and Affiliations

  • Qingwei Xu
    • 1
  • Carlos Barrios
    • 2
  • Teresa Cutright
    • 3
  • Bi-min Zhang Newby
    • 4
  1. 1.Qingwei Xu Dept. of Civil Engineering The University of Akron Akron, Ohio 44325-3905 USA
  2. 2.Carlos A. Barrios Dept. of Chemical Engineering The University of Akron Akron, Ohio 44325-3905 USA
  3. 3.Dr. Teresa J. Cutright Department of Civil Engineering University of Akron Akron, OH 44325-3905 USA
  4. 4.Dr. Bi-min Zhang Newby Department of Chemical Engineering The University of Akron Akron OH 44325-3905 USA

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