10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 1 2015 (January - March) Polyhydroxybutyrates (PHBs) are an attractive alternative to conventional non-biodegradable plastics, as these have physical properties similar to polypropylene and are also fully biodegradable. In the present study, an attempt was made to isolate efficient PHB producing bacteria from effluent discharge sites of different industries. Using Sudan Black screening method, 20 PHB positive bacteria (PHB yield varying between 12.11 to 82.53 mg/ml) were isolated from contaminated soil samples. Chemical nature of the extracted polymer was confirmed using FTIR analysis. Based upon their biochemical characterization, the isolates were tentatively found to belong to three prominent genera, lessThan i greaterThan viz lessThan /i greaterThan ., lessThan i greaterThan Bacillus lessThan /i greaterThan , lessThan i greaterThan Staphylococcus lessThan /i greaterThan and lessThan i greaterThan Acinetobacter lessThan /i greaterThan . Culture medium conditions having glucose as carbon source, ammonium sulphate as nitrogen source, C:N ratio as 20:1, pH at 7.0, and an incubation temperature of 30 lessThan sup greaterThan 0 lessThan /sup greaterThan C were found to support maximum PHB production by all the isolates. At optimized conditions, a few isolates (IBB, ITF and ITG) exhibited significant PHB yields, thus showing a potential for their possible industrial exploitation. KIRAN NEHRA, NIDHI DAHIYA, PRIYANKA LATHWAL AND MANPREET SINGH Biodegradable, biochemical characterization, culture medium parameters, optimization, PHB. 676-691