Effect of gamma irradiation on cell lysis and polyhydroxyalkanoate produced by Bacillus flexus

Divyashree, M. S. and Shamala, T. R. (2009) Effect of gamma irradiation on cell lysis and polyhydroxyalkanoate produced by Bacillus flexus. Radiation Physics and Chemistry, 78 (2). pp. 147-152. ISSN 0969-806X

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Abstract

Bacillus flexus cultivated on sucrose and sucrose with plant oil such as castor oil produced polyhydroxybutyrate (PHB), a homopolymer of polyhydroxyalkanoate (PHA) and PHA copolymer (containing hydroxybutyrate and hexanoate), respectively. Gamma irradiation of these cells (5-40kGy) resulted in cell damage and aided in the isolation of 45% and 54% PHA on biomass weight, correspondingly. Molecular weight of PHB increased from 1.5105 to 1.9105 after irradiation (10kGy), with marginal increase of tensile strength from 18 to 20MPa. At the same irradiation dosage, PHA copolymer showed higher molecular weight increase from 1.7105 to 2.310 5 and tensile strength from 20 to 35MPa. GC, GC-MS, FTIR and 1H NMR were used for the characterization of PHA. Gamma irradiation seems to be a novel technique, to induce cross-linking and molecular weight increase of PHA copolymer and aid in easy extractability of intracellular PHA, simultaneously.

Item Type:	Article
Uncontrolled Keywords:	Bacillus flexus Gamma irradiation Polyhydroxyalkanoate copolymer Polyhydroxybutyrate FTIR spectrum 1H NMR spectrum
Subjects:	600 Technology > 08 Food technology > 09 Food Microbiology
Divisions:	Food Microbiology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	17 Mar 2010 06:55
Last Modified:	17 Mar 2010 06:55
URI:	http://ir.cftri.res.in/id/eprint/9036

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