Hardass microbes are colonising your kitchen

Extremophiles are superhardy microbes that can live in some of the toughest environments Mother Nature provides - from the frozen wastes of the Antarctic to highly-acidic mine tailings. Now you can add your kitchen to that list.

A paper published in the journal Fungal Biology details the discovery of a novel type of fungus found living on the rubber seals of dishwashers. Zalar et al. sampled 189 machines in over a hundred towns and cities across the world. A plethora of fungal species were recovered, including some harmful to human health.

Fungi such as Aspergillus, Candida, Penicillium cropped up 62% of the kitchens, but the most common discovery were the black yeasts Exophiala dermatitidis and Exophiala phaeomuriformis, which were found in over half of the dishwashers. The ultra-hardy fungi appear to have evolved specifically for their new environment, showing a previously unrecorded combination of tolerances toward heat, high salt concentrations, aggressive detergents, and both acid and alkaline water. One of the black yeasts, Exophiala dermatitidis, is rarely found in nature and can be pathogenic in humans, frequently colonising the lungs of cystic fibrosis patients and occasionally causing fatal infections in healthy humans.

There's no word yet on whether the fungi present a direct risk to homeowners, so for now marvel at the fact that domestic engineering creates a little piece of hell on earth for microbes - but nothing they can't handle.

Zalar P, et al., Dishwashers - A man-made ecological niche accommodating human opportunistic fungal pathogens, Fungal Biology (2010), doi:10.1016/j.funbio.2011.04.007