TABLE 2.
Natural QS inhibitors observed in algae and major symbiotic bacteria
| Species | Compound | Mode of action | Biological role | QS system affected | References |
|---|---|---|---|---|---|
| Red alga, Ahnfeltiopssis flabelliformis | α-D-galactopyranosyl-glycerol (Floridoside), betonicine, and isoethionic acid | Competes with AHL signals | Kim et al. (2007a, b) | ||
| Red alga, Galaxa uraceae, Laurencia sp. | Unidentified algal extract | AHL inhibitor | Skindersoe et al. (2008) | ||
| Green alga, Chlamydomonas reinhardtii | Unidentified AHL mimics, Lumichrome | Blocks AHL molecules | Rajamani et al. (2008); Teplitski et al. (2004) | ||
| Brown alga, Laminaria digitata | Oxidized halogen HOBr, Hypobromous acid | Deactivates AHL by interfering with QS genes | Borchardt et al. (2001) | ||
| Macroalga, Delisea pulchra | Furanone | MimicsAHLsignals, inhibits gene expression | Affects biofilm formation, swarming motility, toxin production, chemotaxis | Swr system of S. liquefaciens and other gram negative bacteria | Givskov et al. (1996); Gram et al. (1996); Manefield et al. (2000) |
| Macroalga, Chlorophyta, Caulerpa sp. | Unidentified extract | AHL inhibitor | Skindersoe et al. (2008) | ||
| Marine algal | Honaucin, coibacin, laurencione, tumononic acid, and malyngamide | QS inhibitor | Vibrio harveyi | Gerwick et al. (2013) | |
| Microalga, Chlamydomonas reinhardtii | Lumichrome | Mimics AHL signals | Rajamani et al.(2008) | ||
| Bacteria | |||||
| Penicillium spp. | Penicillic acid, patulin | Las and RhI system of P. aeruginosa | Rasmussen et al. (2005) | ||
| Bacillus spp., Agrobacterium tumefaciens, Arthrobacter sp. | Lactonase | Degradation of AHL signals | Romero et al.(2011) | ||
| Bacillus spp., Alteromanas sp., Tenacibaculum discolor strain; Nocardioides sp. Streptomycetes sp. | Acylase | Degradation of C4-HSL, 3-O-C12-HSL, and long chain AHLs | Kang et al. (2004); Nithya and Pandian (2010); Romero et al. (2011) | ||
| Bacillus megaterium | AHL-oxidase | Degradation of C4 HSL and 3-O-C12 HSL | Choudhary et al. (2007) | ||
| Burkholderia strain GC4 | AHL-oxidoreductase | Degradation of 3-O-C6 HSL | Chan et al. (2011) | ||
| Streptomycetes spp. | Lactones | Mimics AHL signals | Cho et al. (2001) | ||
| Xanthomonas campestris | Cys-11-methyl-2-dodecenoic acid | Mimicsfarnesoic acid signals of C. albicans | Zhang and Dong (2004) | ||
| Staphylococcus xylosus | RNA III inhibiting peptide | Competes with QS signals | Gov et al. (2004) | ||
| Halobacillus salinus | Phenethylamide | Antagonist of AHLs | Teasdale et al. (2009) | ||
| Cyanobacteria, Blennothrix cantharidosmum | Tumonoic acids | Competes with QS signals | Clark et al. (2008) | ||