THE DEPENDENCE BETWEEN ULTRASONIC EXPOSURE TIME AND BIOLOGICAL REACTIONS IN THE PARAMECIUM

Abstract

The effects of ultrasonic irradiation at different frequencies, i.e. 0.25, 0.5, 1, and 5 MHz, on the activation of the single cell creature biological reaction have been investigated. The ability shown by ultrasound in promoting and/or accelerating many reactions has been shown to be a useful field. The resonance frequency of Paramecium by using the ultrasound irradiation is an important parameter in this study. All other parameters being keep constant, it has been ascertained that an appropriate frequency value of ultrasound can be selected, capable of driving a biological reaction to its suitable yield. The oscillation of the cells in response to the ultrasound radiation is simulated using Rayleigh-Plesset's bubble activation theory. The resonance frequency of the unicellular creature is then calculated. In our experiment, the resonance (0.5 and 1 MHz) and non-resonance (0.25 and 5 MHz) frequencies were employed. The resonance frequency of the Paramecium vacuole is among 0.5013 ∼ 1.2703 MHz. When the 0.5 and 1 MHz frequencies of ultrasound was irradiated in the samples, the relative growth rate was about 30% higher than that of unexposed sample. It is obviously that the inhibition or enhancement growth conditions did not appear during irradiation the non-resonance frequency ultrasound. In addition, experimental evidence suggests that the sustaining growth effect can be expected, when the irradiation time is divided into parts.