The effect of audible sound waves on the growth of Escherichia coli

Cho, Joanna Lee Ying (2007) The effect of audible sound waves on the growth of Escherichia coli. Universiti Malaysia Sabah. (Unpublished)


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The rationale of this study is to find a cheaper alternative other than ultrasound in order to control the growth of microbes. This could be beneficial to the practical microbiological technology development. In this study, sound treatments of 1000 Hz, 5000 Hz, 15 000 Hz and control (without sound) were used to assess the effect of audible sound waves on the growth of Escherichia coli. A standardized E. coli suspension of fixed concentration was used for inoculation throughout the experiment in nutrient agar and nutrient broth. The first incubation of the samples was done at 37°C for three hours. For the second incubation, the samples were incubated at room temperature (24 ± 2°C) in an acoustic chamber, JedMark LV -1 at various sound treatments; five hours for nutrient broth and 16 hours for nutrient plates. The parameters in this study were cell mass (turbidity measurement) and cell numbers (direct cell count and plate count). Results showed that sound treatment of 5000 Hz was able to give a significant increase of 25.2 percent direct viable cell count of E. coli and also plate counts which nearly double the numbers of colonies formed compared to the 1000 Hz sound treatment. The sound treatment of 15 000 Hz indicated a significant increase of 16.7 percent of cell mass of E. coli compared to 5000 Hz. In conclusion, the results of this study revealed that audible sound waves do have effects on the growth of E. coli.

Item Type: Academic Exercise
Uncontrolled Keywords: ultrasound, growth of microbe, Escherichia coli, audible sound, incubation, temperature, sound treatment, turbidity measurement
Subjects: S Agriculture > SB Plant culture
Divisions: SCHOOL > School of Science and Technology
Date Deposited: 20 Feb 2014 05:20
Last Modified: 12 Oct 2017 00:04

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