Quorum Sensing Inhibition by EOSLs. Antiquorum sensing activity of essential oils alone, Oleic acid sophorolipid alone, and the newly synthesized EOSLs was performed using method described elsewhere with slight modifications.
Antibiofilm Activity of the Synthesized EOSLs. Biofilm formation is another phenotype governed by quorum sensing.
These observations led to the musing that if the EOs could be converted into their corresponding EOSLs they might acquire indigenous QS inhibition property.
For synthesizing these EOSLs, Candida bombicola ATCC 22214 was used as the producer organism.
Interestingly it was observed that oils that were not showing any QSI activity before, either alone or in combination with OASL, became potent inhibitors of quorum sensing mediated phenotypes upon transformation into their corresponding EOSLs (Table 1).
FTIR analysis demonstrated that synthesized EOSLs show certain peaks similar to those of OASL; however, certain new peaks could be seen in the spectra of the synthesized EOSLs.
In our study antibiofilm activity of selected EOSLs but not EOs have been analyzed as they are expected to have improved ability to inhibit initial adhesion of microorganisms to solid surface due to their biosurfactant like property in addition to their antimicrobial and quorum sensing inhibitory property.
This paper highlights the advantage of conversion of EOs to EOSLs because this conversion reaction bestows additional chemical and physical properties to the component EOs making them better quorum sensing inhibitors and powerful anti-biofilm agents.