Abstract
Polyhyroxyalkanotes (PHAs) are a family of polyhydroxyesters synthesized by numerous bacteria as an intracellular carbon and energy storage compound under nutrient-limiting conditions with excess carbon. An extensive screening program was previously done to isolate a promising bacterial isolate capable of polyhydroxyalkanoate (PHA) production. Polyhydroxalkanoates are biodegradable thermo polyesters like poly-β-hydroxybutyrate (PHB), which can be produced intracellularly as carbon and energy reserves. In this present study, out of 35 isolates, as many as 12 isolates were found to accumulate PHA which isolated from the oil and plastic contaminated soils, collected from different contaminated sites in Baghdad. However only one bacterial colony is selected among others based on maximum PHA yield (4.8g/L) after 48 hrs of incubation at 30°C with 54 % of PHA. Bacteria from this colony was characterized by morphological, biochemical and identified as Azotobater. The maximum PHA yield was recorded under the dry weight basis with 3% of corn oil wastes as the sole carbon source. However, Sudan black stained cells showed the presence of large quantities of granules in the cell cytoplasm when viewed under microscope. The polymer was extracted for the purpose of studying its physical and chemical properties.
