Anti-biofilm activity of marine algae-derived bioactive compounds

Abstract

A large number of microbial species tend to communicate and produce biofilm which causes numerous microbial infections, antibiotic resistance, and economic problems across different industries. Therefore, advanced anti-biofilms are required with novel attributes and targets, such as quorum sensing communication system. Meanwhile, quorum sensing inhibitors as promising anti-biofilm molecules result in the inhibition of particular phenotype expression blocking of cell-to-cell communication, which would be more acceptable than conventional strategies. Many natural products are identified as anti-biofilm agents from different plants, microorganisms, and marine extracts. Marine algae are promising sources of broadly novel compounds with anti-biofilm activity. Algae extracts and their metabolites such as sulfated polysaccharides (fucoidan), carotenoids (zeaxanthin and lutein), lipid and fatty acids (γ-linolenic acid and linoleic acid), and phlorotannins can inhibit the cell attachment, reduce the cell growth, interfere in quorum sensing pathway by blocking related enzymes, and disrupt extracellular polymeric substances. In this review, the mechanisms of biofilm formation, quorum sensing pathway, and recently identified marine algae natural products as anti-biofilm agents will be discussed.

Keywords: algae extracts; anti-biofilm activity; biofilm; marine natural products; quorum quenching; quorum sensing; quorum sensing inhibition.

Figure 1

The cycle of biofilm evolution from planktonic cells to detachment of planktonic cells.

Figure 2

Chemical structure of quorum sensing signal molecules.

Figure 3

Mechanism of quorum sensing inhibition against biofilm formation. (A) AIs synthesis inhibition, (B) Degrading AIs by AHL-lactonases, (C) Interference of the signal receptors by AI antagonists, (D) Interference of the response regulators resulting in signaling cascade disturbing, (E) Reduction of the extracellular AIs resulting in inhibited cell-to-cell signaling. *AIPs are produced inside the bacterial cell as pro-AIP which will be processed and modified inside or outside the cell hinge upon the organism.