Dissertations and Theses @ UNI
Availability
Open Access Thesis
Keywords
Bacteriology--Cultures and culture media; Propylene oxide; Sterilization;
Abstract
The effective use of propylene oxide as a sterilizing agent has been demonstrated by many workers. Its use in the high school has been suggested but not studied. The intent of this work was to ascertain the feasibility of such an application. Preliminary experiments were performed to determine the most effective concentration of propylene oxide exposure in a closed system to achieve sterilization. For heavily contaminated plates a concentration of 2.0 ml/L of propylene oxide for twenty-four hours was found to be most effective. Comparison tests were made of both propylene oxide and pressure cooker sterilized nutrient agar. Sources of contamination were exposure to air and inoculation with Bacillus subtilis and Sarcina lutea. Comparisons were made of plate counts between the two sterilizing agents on plates exposed to air for ten minutes and incubated at ambient conditions for ninety-six hours. Results of these comparisons indicated a difference in the capacities of pressure sterilized media and propylene oxide exposed media to support microbial growth. Growth on previously exposed plates was found to be significantly less than on media sterilized by conventional means. Streptomycin and terramycin antibiotic discs tested against Bacillus subtilis suggest that propylene oxide exposure has effects not apparent on pressure sterilized agar. Streptomycin discs gave a larger zone of inhibition on propylene oxide exposed media while terramycin zones were smaller. In addition, there were secondary zones of inhibition on pressure sterilized media with terramycin discs. No such zones were noted on propylene oxide sterilized media. Propylene oxide sterilization of starch agar for demonstrating hydrolysis of starch by germinating corn seeds was effective. The exposure to propylene oxide reduced the numbers of fungi colonies introduced with the com. However, germination time for corn on propylene oxide treated media was increased. This was not deemed critical in relation to the nature of the experiment for high school use. The use of propylene oxide in the high school for media sterilization is feasible if proper precautions are taken when using the chemical. The use of propylene oxide is not recommended when critical results are desired.
Year of Submission
1973
Degree Name
Master of Arts
Department
Department of Biology
First Advisor
Robert C. Goss
Second Advisor
Daryl D. Smith
Third Advisor
James Macmillan
Date Original
1973
Object Description
1 PDF file (52 leaves)
Copyright
©1973 Marvin A. Andersen
Language
en
File Format
application/pdf
Recommended Citation
Andersen, Marvin A., "Propylene Oxide Sterilization of Microbiological Media in the High School Classroom" (1973). Dissertations and Theses @ UNI. 1943.
https://scholarworks.uni.edu/etd/1943
Comments
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