Quorum sensing inhibitors from marine bacteria Oceanobacillus sp. XC22919

Abstract

In this study, three active compounds isolated from Oceanobacillus sp. XC22919 were identified as 2-methyl-N-(2′-phenylethyl) butyramide (1), 3-methyl-N-(2′-phenylethyl)-butyramide (2) and benzyl benzoate (3), and were first reported to exhibit the apparent quorum sensing inhibitory activities against C. violaceum 026 and P. aeruginosa. Compounds 1–3 inhibited violacein production of C. violaceum 026 by 10.5–55.7, 11.2–55.7, and 27.2%–95.7%, respectively, and inhibited pyocyanin production of P. aeruginosa by 1.7–50.8, 39.1–90.7, and 57.2%–98.7%, respectively. The azocasein-degrading proteolytic rates of P. aeruginosa were observed by 13.4–31.5, 13.4–28.8, and 11.3%–21.1%, respectively. With respect to elastase, the range of inhibition of activity of compounds 1–3 was 2.1–30.3, 4.2–18.2, and 8.9%–15.7%, respectively. Compounds 1 and 3 also showed a concentration-dependent attenuation in biofilm formation, with the maximum of 50.6% inhibition, and 37.7% inhibition at 100 μg/mL, respectively.

Keywords:

• Marine bacteria
• Oceanobacillus sp. XC22919
• quorum sensing
• quorum sensing inhibitors
• secondary metabolites
• virulence factors
• pathogens