Evaluation of Alkylresorcinol Production by Pseudomonas spp.

Alkylrecorcinols (ARs) are a group of non-isoprenoid lipids belonging to the phenol group. Biologically important properties have been conferred to ARs such as antifungal and antibacterial. These metabolites have been found in various organisms being rhizobacteria an important source of ARs. Knowing that bacteria of the genus Pseudomonas biosynthesize ARs, these bacteria become an alternative for the control of pathogenic microorganisms. The aims of this study were to evaluate the production of intracellular (AR_IN) and extracellular (AR_EX) ARs in liquid cultures of a set of Pseudomonas strains obtained from rhizosphere of Physalis peruviana. In addition, by constructing growth curves, quantification and identification of ARs by colorimetric and LC-DAD methods, respectively, it was determined the best AR-producer strain and the optimum time of production. Test strains showed an AR production peak at exponential growth phase, as well as a peak during the stationary phase by intracellular contents, with amounts between 0.44 and 4.8 µg/mL for AR_EX and 0.20 and 2.4 µg/mL for AR_IN. In conclusion, production of this metabolite is not constant in time. PS-11 was the fastest growing strain with highest AR_IN production. PC-20, despite of its slow growth, produced the highest amount of AR_EX. Additionally, seven AR-related metabolites were also identified for the best AR-producer strain by a LC-DAD-based derivatizing method.