Dr Michelle Dickinson: Kitchen sponges are better than petri dishes

Kitchen Sponges! 
New research out this week shows that the structure of your kitchen sponge makes it a better incubator for growing diverse bacterial communities than even a laboratory Petri dish! 
It seems that – like humans, some bacteria thrive in a diverse community while others prefer more of a solitary existence. The great thing about a kitchen sponge is that it provides a physical environment that allows all kinds of bacteria to find their favourite living conditions leading to a high level of biodiversity (or lots of different types of bacteria) on your sponge. 
The research published in the journal Nature Chemical Biology https://www.nature.com/articles/s41589-021-00961-w took 80 different strains of E. coli and mixed the bacteria in laboratory petri dishes in different combinations.  Some had spaces with lots of different living spaces where all the microbial species could mix freely, others were smaller and mimicked spaces where species could keep to themselves. 
What they found was that regardless of the size of the petri dish – the results were the same – only one or two bacteria strains survived. 
The small petri-dishes hurt the species that depended on interactions with other species whereas the large petri-dishes hurt the loner species who don't like interactions with others. 
They ran the experiment with a strip of household sponge and found it to be a better incubator of microbial diversity than any of the laboratory equipment they tested thanks to the large and small spaces which kept all the bacterial species happy. 
This study follows on from previous ones. A 2017 study in Nature identified 362 different types of bacteria in 14 sponges – the only other place with this much bacteria is the human intestinal tract. 
A 2017 study in the Journal of Food Protection found that 44 percent of kitchens contained fecal bacteria, which was primarily found in sinks, sponges and dishcloths. 
If all of this info has got you looking at your sponge in a new way – don't panic, there are some really simple ways to disinfect it. 
1 - Dishwasher – throw your sponge in the dishwasher with your dishes. 
2 - Microwave – place in a bowl of water and microwave until the water boils 
3 - Bleach – dip in a bowl of water with bleach for a couple of minutes

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