Characterization of the Polyhydroxyalkanoates (PHAs) Degradation by an Isolated Pseudomona spp from Herat-Worm Compost

MIYAZAKI SS; SARTI GC; GALELLI MI; BONDESIO MI; CASAS C; TRINCHERO MF; MONZÓN A

San Carlos de Bariloche

Congreso; XXXIX XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular-XXXII Reunión Anual de la Sociedad Argentina de Biología; 2003

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular-Sociedad Argentina de Biología

Polyhydroxyalkanoates (PHAs) are accumulated as an intracellular organic carbon storage by different bacteria, under unbalance growth conditions. The thermoplastic characteristics of these polyesters and the biodegradability has attracted much attention as environmentally degradable plastic materials. An extracelular PHAs depolymerase of Pseudomona spp. isolated from earth worm compost was characterized. The enzyme was secreted by the bacterium to the culture medium only when was cultivated on poly 3-hydroxybutyrate-co-3-hydroxyvalerate (p3HBco- 3HV) as the sole carbon source. When yeast extract was added to the culture broth, Pseudomona spp. grew well but the depolymerase activity was not detected in the culture supernatant. The secreted enzyme was purified by chromatographic method fast performance liquid chromatography (FPLC). The molecular mass was determined as 45.000 by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate. The purified enzyme was stable at temperature below 35ºC and at pH value of 7,0 and can depolymerized PHAs. Kinetics of enzymatic activities were measured on PHAs films and commercial PHAs powders (they were used after purification and aged). The purified enzyme has higher affinity for PHAs films.