Photo Mk2010, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons

Dear Readers, you would think, would you not, that the inside of a microwave would be a very hostile environment for a bacteria to live in. After all, the thing works via a magnetron, which produce microwaves – these then bounce off the metal interior of the microwave and penetrate whatever’s in the oven, causing the water molecules to vibrate and to heat up. Not a happy place for anything with water in its body, which would be practically anything. Add in the fact that microwaves in laboratories are used to sterilise equipment, and you’d think that the buggies wouldn’t stand a chance.

However, like all good scientist, Manuel Porcar from the University of Valencia decided to see if this was actually true. He and his team sampled 30 microwaves: 10 from single-household domestic kitchens: 10 from mixed-use settings (such as the dreaded office microwave) and 10 from microbiology laboratories. In all, he discovered bacteria from 747 different genera in the microwaves. The household appliances had the least bacterial diversity, and the laboratories had the most – not surprising when you think of all the different kinds of experiments that the equipment in the microbiology microwaves might have represented.

In the domestic and office microwaves, the bacteria overlapped and were usually species that live on human hands or in food – they don’t seem to need special adaptations to survive in the microwave, possibly because the food particles protect them. In the laboratories, however, the bacteria that survived were more likely to be extremophiles, specially adapted for desert/irradiated conditions.

Porcar does not think that the bacteria in domestic and office microwaves are any worse than the bacteria found on hands, or in the rest of the kitchen – it just points up the need to clean the microwave as often as you clean other food preparation areas. My hunch is that the worst places are probably office microwaves, where it’s no one’s responsibility to clean the microwave and so nobody does (ditto office fridges). It makes me glad that I’ve retired!

Another scientist, Belinda Ferrari at the University of New South Wales, suggests that analysing the ‘microwave biome’ before and after cleaning might be an interesting way to see what else, apart from microwaves, bacteria can survive. Some species are resilient little devils, for sure.

You can read the whole paper here.

And here is a brief grumble. Just a brief one. I have been increasing my steps a little every day, and today I managed over 3000 for the first time. However, I am still walking with a limp, and what it seems to be doing is throwing out my back, which is more painful than it’s been for years. Harrumph. I am a little afraid that I’m going to end up with sciatica, so I might have a rest day tomorrow and just do a little gentle wandering around. Fortunately I see the physiotherapist next Tuesday, so hopefully I can get some suggestions. I do feel as if progress is being made, and I am so pleased and grateful overall.

As you were! As Dame Julian of Norwich said, “All shall be well, and all shall be well,  all manner of things shall be well”. And I am also quite partial to “This too shall pass”. Any other phrases that spring to mind when times are tough, Readers?

Statue of Dame Julian of Norwich by David Holgate outside Norwich Cathedral, Photo By User:Poliphilo – Crop of https://commons.wikimedia.org/wiki/File:Statue_of_Dame_Julian.JPG,, CC0, https://commons.wikimedia.org/w/index.php?curid=117908925