A team of Spanish scientists from the Institute of Integrative Systems Biology (I2SysBio), the University of Valencia-CSIC and Darwin Bioprospecting Excellence SL (Valencia) has identified 101 strains of bacteria in samples from 30 microwave ovens.

Most of the bacteria belonged to the groups Bacillus, Micrococcus and Staphylococcus. Besides, pathogenic bacteria were found in home microwave ovens: Klebsiella, Enterobacter and Lactococcus, which manage to "survive and multiply" and get on the heated products if the microwave is not cleaned in time after use.

Scientists are particularly concerned about the presence of bacteria in laboratory microwave ovens. These microorganisms are resistant to high temperatures and various types of radiation. While the authors of the study did not make specific conclusions, they did emphasize the need for further research into bacteria that can survive in aggressive environments.