Kinetics of biofilm formation of Pseudomonas plecoglossicida in the presence of an annonaceous acetogenin, squamocin, and its relation to biodegradation of naphthalene”

EDUARDO ALBERTO PARELLADA; MARCELA FERRERO; ALICIA BARDÓN; ELENA CARTAGENA; ADRIANA NESKE

San Miguel de Tucuman

Congreso; VII Congreso Argentino de Microbiologia General "Samige del Bicentenario"; 2011

Sociedad Argentina de Microbiologia General

Kinetics of biofilm formation of Pseudomonas plecoglossicida in the presence of an annonaceous acetogenin, squamocin, and its relation to biodegradation of naphthalene   Eduardo Parellada1,3, Marcela Ferrero2, Alicia Bardón1,3, Elena Cartagena1, Adriana Neske1   1 Instituto de Química Orgánica, Facultad de Bioquímica, Química y Farmacia UNT. E-mail: aneske@fbqf.unt.edu.ar 2 PROIMI-CONICET. 3 INQUINOA–CONICET.   Squamocin, an annonaceous acetogenin extracted from <i>Annona cherimolia</i> (“chirimoya”), has been shown to increase the biofilm production of <i>Pseudomonas plecoglossicida</i>, a polycyclic aromatic hydrocarbons degrading bacterium, by induction of autoinducers production. Biofilm-mediated bioremediation presents a proficient and safer alternative to bioremediation. Due to its carcinogenic and toxic properties, naphthalene is considered a priority pollutant for bioremediation. Natural products, as squamocin could enhance the efficiency of bioremediation processes. In this work we study the kinetics of biofilms formation of <i>P. plecoglossicida</i>in the presence and absence of squamocin and its relation to the rate of degradation of naphthalene. The kinetics of biofilm formation was carried out by measuring absorbance at 560 nm in a microplate spectrophotometer (Biotek-Power Wave XS2 with GEN5 data analysis software). Measurements were taken every hour for a 12 hours period. Naphthalene degradation was assessed by RP-HPLC with an UV/visible detector (wavelength 276 nm). The inicial naphthalene concentration was 1mM. Treatment with squamocin at 2.5 &mu;g.ml^-1 produced 47% stimulation in the production of biofilms of the strain <i>P. plecoglossicida</i>at 6 h of incubation (p&le;0.05). At the same time, the most significant difference in naphthalene consumption between control (18%) and treated (43%) assays was registered. The rate of consumption of naphthalene at 6 h was determined by mathematical treatment of experimental data. At that time of incubation, the calculated speed of degradation in the control assay was 21.5 &mu;g.h^-1, against 38.1 &mu;g.h^-1 in squamocin treated assay. Data analysis also showed that at this time, the biofilms formation was almost reaching stationary phase or, which is the same, reaching its maximum value. The results of the kinetics of biofilms and quantification of residual naphthalene, enabled us determine that the naphthalene consuming was increased with the biofilm production. This led us to conclude that the increase in the naphthalene degradation is due perhaps to an increase in the production of biofilms since the biofilm phenotype is more suitable for bioremediation.