Polyhydroxybutyrate (PHB), produced by many microorganisms during stress condition, is an eco-friendly biodegradable polymer which can completely replace the petroleum-based commercial plastics. The study was aimed to screen a potent PHB producing bacterium from municipal dumpsite areas and to analyse the effects of nutritional and environmental factors to enhance production of PHB. Acinetobacter sp. K3 was a potent PHB producing soil bacterium identified by morphological, biochemical and molecular techniques. The 16S rDNA nucleotide sequence of the bacterium was assigned the accession number: KT907046 in NCBI database. Effects of different carbon, nitrogen, pH and temperatures on PHB production were analysed to enhance its product yield. It grows at the rate of 0.105 g/h/L and PHB production achieved up to 4.8 g/L from 6.04 g/L DCW (dry cell weight) and PHB contents amounts to 79.4 % w/w of total DCW. The above accumulated PHB was obtained at pH 8, temperature 400C, mannitol and urea used as carbon and nitrogen sources respectively. Further, phbA, phbB and phbC genes responsible for PHB production was amplified which confirms the presence of PHB using the gene specific primers by polymerase chain reaction (PCR) technique. This new strain could be used for further industrial production of biopolymer.
Key words: Acinetobacter; biodegradable polymer; polyhydroxybutyrate; PCR; 16S rDNA sequencing
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