Scientists have discovered that microwaves are home to a surprisingly wide range of bacteria. Researchers at the University of Valencia in Spain analyzed samples from 30 microwave ovens in different settings. They found up to 747 different genera of bacteria within 25 bacterial phyla.
The study looked at microwaves in single-household kitchens, shared corporate and scientific kitchens, and molecular and microbiology laboratories. The diversity of bacteria was lowest in single-household microwaves and highest in laboratory appliances. Many of the bacteria found in domestic and shared microwaves were similar to those typically found on human hands and other kitchen surfaces.
This suggests that microbes do not need special adaptations to survive in a microwave.
Bacterial diversity in household microwaves
Some bacteria identified in domestic microwaves, like Klebsiella and Enterococcus, may pose health risks.
However, the research indicates that the microbial population of microwaves does not present a unique or increased risk compared to other kitchen surfaces. “What is clear is that one cannot trust a microwave to be a cleaner environment in terms of microorganisms compared to another kitchen surface. They must be cleaned like the rest of the kitchen,” says the lead researcher.
The researchers recommend regularly cleaning microwaves with disinfectant products, especially in workplaces where hygiene may often be neglected. They also suggest studying the bacterial populations before and after cleaning to better understand the impact of cleanliness on microwave microbiomes. The study highlights the unseen microbial diversity inside common household appliances.
It underscores the importance of regular cleaning practices to maintain a hygienic environment in our kitchens.
