Production of PHB (polyhydroxybutyrate) by rhodopseudomonas palustris KU003 and rhodobacter capsulatus KU002 under phosphate limitation.

ABSTRACT

Nine bacterial species of purple non sulphur bacteria were isolated from Warangal district of South India from leather industry effluents which included Rhodopseudomonas palustris, R.rutila, R.acdiophila, Rhodopila globiformis, Rhodospirillum rubrum, Rsp.photometricum, Rhodobacter sphaeroides, Rb.capsulatus, Rhodobacter sp and Rhodocyclus gelatinosus were isolated. Among these Rhodopseudomonas palustris KU003 and Rhodobacter capsulatus KU002 were selected for the production of Polyhydroxybutyrate (PHB). The extracted PHB was characterized by IR and NMR spectral analysis. Effect of nutrient limitation in the form of phosphate KH2PO4 was tested to enhance the production of the polymer. Maximum yield of PHB was recorded at a concentration of 280 mg/L of KH2PO4 in Rps.palustris while no significant increase in the production of the polymer was observed in Rb.capsulatus.