Abstract

Overview

Radio frequency (RF) non-thermal (NT) bio-effects on Saccharomyces cerevisiae yeast growth have been systematically investigated, addressing the debate over potential health risks or beneficial applications of RF exposure.

Methodology and Devices Used

• A transverse electro-magnetic (TEM) device paired with dielectric spectroscopy for RF frequency selection was employed.
• The device comprises two 240-μL chambers 3D printed for cell cultures and operates up to a few GHz, delivering uniform RF fields.
• A vector network analyzer provided ~20 dBm continuous-wave (CW) RF power.

Experimental Findings

• Frequency regions exhibiting large permittivity differences (1.0 MHz, 3.162 MHz, 10 MHz) were selected for testing RF's effect on yeast growth.
• RF field at 3.162 MHz decreased yeast growth rates by 15.1%, while at 1.0 MHz, an enhancement of 13.7% was observed, indicating frequency-dependent non-thermal effects.
• These differences might influence nutrient transport near the cell membrane.
• Control comparisons were done with one at the same temperature, and another 1 degree C higher.

Conclusion and Further Research

This study confirms the presence of RF non-thermal effects on yeast growth, which are dependent on the frequency. The hypothesized mechanisms, such as non-uniform RF fields and fluidic diodes in cell membrane ion channels, suggest crucial roles in nutrient transport but require further verification.