Microbial Production and Characterization of Poly(beta-hydroxybutyrate) from a Bacillus sp. Strain Isolated from Marine Sediments

J.C. HIGUITA; J.M. NARANJO; J.A. LÓPEZ JIMÉNEZ; M.A. CUBITTO; M.A. VILLAR

Clearwater Beach, Florida

Simposio; 32nd Symposium of Biotechnology for Fuels and Chemicals; 2010

Society for Industrial Microbiology

In this work, the conditions and capabilities of  poly(beta-hydroxybutyrate) (PHB) production by a Bacillus sp. strain were studied. The Bacillus sp. Strain was isolated from superficial sediments of Bahía Blanca Estuary (Buenos Aires, Argentina). PHB production in the presence of  an excess carbon source with the restriction of at least one essential growth nutrient  such as nitrogen was analised. PHB fermentation was carried out for 36 h in a 3.7 liters Lab Fermenter (Bioengineering, Switzerland) using a grown medium with a composition of 20 g/L glucose, 1 g/L NH4NO3, 2.5 g/L K2HPO4, 2.5 g/L MgSO4 7 H2O, 2.5 g/L KH2PO4, 2.5 g/L NaCl, 0.5 g/L FeSO4 7 H2O, and 0.05 g/L MnSO4 4 H2O. After fermentation, the cells were harvested by centrifugation at 6,000 rpm for 20 min and then the intracellular PHB was extracted by using the dispersion extraction method using chloroform and sodium hypochlorite. The extracted PHB was then characterizated by 1H and 13C-Nuclear Magnetic Resonance and Infrared Spectroscopy. Both techniques were useful in confirming the PHB structure and discarding the presence of another monomeric unit different from beta-hydroxybutyrate. All in all, this Bacillus sp was confirmed to be a PHB producer.