Exposure to microwave irradiation at constant culture temperature slows the growth of Escherichia coli DE3 cells, leading to modified proteomic profiles

Abstract

Despite a few decades of research, interest continues in understanding the potential influences of low energy microwave irradiation on biological systems. In the present study, growth of E. coli DE3 in LB media slowed in the presence of microwave irradiation (max. 10 W) while the temperature of cultures was maintained at 37 °C. Viable cell counts in microwave-irradiated cultures were also significantly lower. When microwave irradiation was ceased, E. coli growth was restored. A top-down proteomic analysis of total proteins isolated from control and microwave-irradiated E. coli cultures revealed differential abundance of 10 resolved protein spots, with multiple proteins identified in each following mass spectrometric analysis. Among these proteins, a number are involved in metabolism, suggesting alterations to metabolic activities following microwave irradiation. Furthermore, four amino acid-tRNA ligases were also identified, pointing to the possibility of stress responses in E. coli under microwave irradiation.