Discovery of Diverse Bacterial Species Thriving Inside Microwaves

The radiation environment inside microwave ovens appears to be unfavorable for microbial survival. However, researchers from the University of Valencia in Spain recently reported in the journal "Frontiers in Microbiology" that they identified over 100 bacterial strains from swab samples collected from microwaves in different locations. The researchers noted that this is the first documented instance of a microbial community existing within microwaves.

By swabbing the interiors of 30 microwaves, including the walls and turntables, sourced from three distinct environments—10 from kitchens, 10 from laboratories, and 10 from shared spaces like cafeterias—the researchers transferred the samples to laboratory petri dishes, which all resulted in significant bacterial growth.

DNA analysis of the bacterial colonies revealed strains primarily belonging to Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes phyla, commonly found on human skin and frequently touched surfaces. Bacteria found in kitchen microwaves included Klebsiella and Acinetobacter, which can cause foodborne illnesses. The research team highlighted that it remains unclear how these bacterial strains survive within microwaves, necessitating further studies to understand their adaptations to high temperatures and electromagnetic radiation.