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A gram-positive bacterium that accumulated PHB was isolated from local garden soil in Bangalore. Based on its morphological and physiological properties, and nucleotide sequence (about 1.5 kb) of its 16S rDNA it was identified as Bacillus thuringiensis IAM 12077. | Turk J Biol 33 (2009) 225-230 © TÜBİTAK doi:10.3906/biy-0808-10 Mutagenesis of Bacillus thuringiensis IAM 12077 for increasing poly (-β-)hydroxybutyrate (PHB) production Pal ADWITIYA, Prabhu ASHWINI, Arun Kumar AVINASH, Rajagopal BADRI, Dadhe KAJAL, Ponnamma VOMSI, Shivakumar SRIVIDYA Department of Microbiology, Centre for PG Studies, SBM Jain College, 18/3, 9th Main, 3rd block, Jayanagar, Bangalore-560011 INDIA Received: 19.08.2008 Abstract: A gram-positive bacterium that accumulated PHB was isolated from local garden soil in Bangalore. Based on its morphological and physiological properties, and nucleotide sequence (about 1.5 kb) of its 16S rDNA it was identified as Bacillus thuringiensis IAM 12077. In this study the PHB-producing capacity of putative mutant strains of Bacillus thuringiensis IAM 12077 was evaluated. A Bacillus sp. identified as a Bacillus thuringiensis IAM 12077 strain capable of producing 10%-15% dry cell weight (DCW) PHB when grown in nutrient broth for 48 h was subjected to random mutagenesis [physical (UV) and chemical (acridine orange)]. Among the UV-mutants screened, 19 putative mutants produced more PHB than the parental, while 2 strains produced less. Of these mutants, B8 exhibited promising PHB accumulation (24.68%; 1.54-fold) with more PHB production (1.3 g/l; 5.4-fold) than the parental strain. Chemical mutagenesis yielded putative mutants, of which 6 had a decrease, 3 had no change, and 2 had an increase (B3, C2) in PHB production. While the increase in accumulation (19.69%, 1.43-fold and 22.22%, 1.62-fold, respectively, for B3 and C2) was comparable to the increase shown by the UV mutant (B8), the yields did not concomitantly increase (0.43g/l, 1.13fold and 0.6g/l, 1.57-fold, respectively). Key words: Bacillus thuringiensis IAM 12077, Poly (-β-) hydroxybutyrate, random mutagenesis Poli (-β-) hidroksibutirat üretiminin artışı için Bacillus thuringiensis IAM 12077’nin mutagenezi Özet: PHB biriktiren gram pozitif bir bakteri .
