ANTIBIOFLM ACTIVITY OF BIOSURFACTANT PRODUCED BY A SPONGE‐ASSOCIATED MARINE COBETIA SP. JCG‐23

Abstract

Marine symbiotically associated microbes play a vital role and are an excellent source of natural compounds that exert wide biological activities. In this study, we have reported on the identifcation, characterization, phylogenetic relationship, and anti-bioflm surface-active compound-producing abilities of marine invertebrate sponge-associated Cobetia sp. JCG-23. Among 24 isolates, a total of fve strains (JCG2, JCG19, JCG20, JCG22, and JCG23) have active surface molecule producing potential on the emulsifcation index assay. Interestingly, the potential candidate JCG-23, produces biosurfactants with low surface tension (22 Nm-1) that exert anti-bioflm activity against Pseudomonas aeruginosa PAO1. The isolate was identifed as genus Cobetia sp. JCG-23 with 99.1% sequence similarity to Cobetia crustatorum (EU909460) based on 16S rRNA genesequence analysis. The large-scale production, purifcation, stability, and characterization of biosurfactant were carried out and its surface activity was determined using the oil drop method. Subsequent spectral analysis such as UV, FT-IR, and GC-MS analysis indicated that the purifed biosurfactant was a hydroxyl fatty acid, namely octadecanoic acid (C18H36O2) with a molecular weight of 284 m/z. Furthermore, the efect of antibioflm activity on the viability of Pseudomonas aeruginosa PAO1 by static ring tube and light and confocal laser scanning microscopy analysis revealed that the octadecanoic acid from Cobetia sp. JCG-23 has strong bioflm dismantle ability against Pseudomonas aeruginosa PAO1. Further characterization of the biosurfactant from the isolate Cobetia sp. JCG-23 can pave the way for developing novel bioactive agents targeting bioflm-forming pathogens on topical and medical devices.