Inactivation of Microorganisms by Gamma Irradiation

Abstract

The purpose of this study was to establish kill curves detailing the sterilization efficiency of 60Co gamma irradiation on non-pathogenic vegetative and spore preparations. This was done by testing the viability of the microorganisms over a range of gamma irradiation exposures. The procedures used to carry out the work will be used in fliture sterilization studies of pathogenic microorganisms for later use as antigen reagents. The initial use of non-pathogenic organisms provided a low-risk method for familiarization with the protocol and resolution of any potential problems. Results showed that 4.0 kOy irradiation over a 12 minute period was required for complete inactivation of Erwinia herbicola. The inactivation of Bacillus afropheus (formerly Bacillus subtilis var globigii (BO)) dry powder required 25kGy over 75 minutes and the inactivation ofBacillus afropheus in liquid suspension required 35 kGy over 105 minutes. These results showed that vegetative cells and spore preparations can be successfully sterilized by gamma irradiation in a short amount of time. These results will be used as starting points to establish kill curves for Risk Group 3 organisms such as Bacillus anthracis and Yersiniapestis. The purpose of this study was to establish kill curves detailing the sterilization efficiency of 60Co gamma irradiation on non-pathogenic vegetative and spore preparations. This was done by testing the viability of the microorganisms over a range of gamma irradiation exposures. The procedures used to carry out the work will be used in fliture sterilization studies of pathogenic microorganisms for later use as antigen reagents. The initial use of non-pathogenic organisms provided a low-risk method for familiarization with the protocol and resolution of any potential problems. Results showed that 4.0 kOy irradiation over a 12 minute period was required for complete inactivation of Erwinia herbicola.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2005
Accession Number
ADA450139

Entities

People

  • B. Ford
  • B. Kournikakis
  • R. E. Hilsen

Tags

DTIC Thesaurus Topics

  • Biological Products
  • Classification
  • Dose Rate
  • Efficiency
  • Gamma Rays
  • Materials
  • Microorganisms
  • National Security
  • Packaging
  • Radiation
  • Radiation Effects
  • Security
  • Spreadsheet Software
  • Standards
  • Sterilization
  • Viability

Fields of Study

  • Agricultural and Food sciences

Readers

  • Approximation Theory.
  • Microbial Pathology