When strawberries go bad
Rhizopus stolonifer is an awesome mold. You’ve probably seen it before, on the peaches in your fruit bowl, or on your bagel, or (hopefully not) attacking your body. It’s a versatile and ubiquitous thing, and it makes great hairy colonies that grow astonishingly quickly.
Here is it causing a post-harvest disease of strawberries. You’re seeing seven days of growth and subsidence.
Quicktime 5+ movie
Time lapse video of delicious strawberries inoculated with the evil mold Rhizopus stolonifer by Kent Loeffler.
The little hairs that seem to be clawing their way up are the sporangiophores. If you squint a bit you can almost see a little grey pinhead (sporangium) atop each one. Those pinheads are filled with fungal spores, each hoping to find its very own strawberry.
- DoctorFungus has a good discussion of Rhizopus spp. implicated in nasty, invasive human disease (zygomycosis). In general, don’t worry about catching a fungal infection from rotten fruit. However, if your immune system is not working right because of HIV or immune-suppressing drugs, be wary of fungi.
- Rhizopus oligosporus, a friendlier cousin of the strawberry mold, is used to produce tempeh. You know, tempeh, that meat-like substance made from fermented soybeans. Buy some from your local grocer or health food store and stir fry it up for dinner.
- The strawberries? No, don’t eat them once they’ve become hairy.
I wonder if this fungus could be a cure for male pattern baldness?
This is awsome!! It looks like cotton candy! yum yum!
amazing colors… Why does it turn green afterwards?
Hiya Nick. Greenish-gray, I’d say. It’s greenish-gray mostly from all the kajillion billions of little spore-bearing pinheads; it’s greenish-gray from the sheer density of the thing. (and maybe your monitor lends a greenish cast?)
Thanks, Prof. Hodge (and all your students) for a great blog. I always look forward to new installments.
I thought it was interesting to see the strawberries in the time lapse really collapse BEFORE the sporangiophores started to sprout up. I suppose that means that the mold has been active in the fruit for awhile before it starts to look bad. I’ve wondered about this in the past. Isn’t it likely that we eat infected fruits and vegetables all the time where molds just haven’t reached the fruiting stage yet? At what stage of development do these molds start generating products that might be harmful to humans?
[…] A lot of people think that a mold is a mold is a mold, but that’s just not so. The mold that’s rotting your lemon is not the same one that’s growing in your maple syrup, or eating your strawberries. In fact, your lemon, maple, and strawberry molds each belong to a different phylum of fungi. Proust said it: The real voyage of discovery consists not in seeking new landscapes but in having new eyes. […]
[…] Welcome to Supermarket Mycology, an irregular series of posts on fungi you might well encounter in your everyday life. We’ve already kicked things off handsomely with time lapses of rotting strawberries and lemons, and of course there was the cautionary tale of the moldy maple syrup. Fungi are more ubiquitous than most people imagine; supermarkets house a surprising number of both good (tasty or useful) and bad (unwanted or ugly) fungi. […]
Great stawberry video! Fruit will never taste the same.
I think its very knowledge nourishing.Congratulations for your great effort.
I think that plate is done for. Grandma’s going to be mad!
[…] of disgusting things? Seems like every fungus is out to make its own kind of mess: molds turn your strawberries to mush, stinkhorns turn your mulch into putrescence, and inky caps (genus Coprinus) turn themselves into a […]
yum!! at the end that looks so yummy!!! n that plate should go in the bin!!
I wonder at the end of the video what the strawberries would look like behind the mold.
why does other fruits do the same as the strawberrey? Like as a banna it goes bad at first. turns brown then you start seening these mold and it smells terrible. How come other fruits smell as bad than the bannana.
@ zippidydooda
I doubt there would be much to see.
Great strawberry video
Yes, awesome video.
That was pretty cool I mean the mold just kept growing long after it had covered the berries.
Although mold is, of course, cool, berry fans will want to check out this amazing tip on mold prevention from the New York Times.
[…] LBM (little brown mushroom) of some sort that seems to be getting parasitized by a zygomycete (like Rhizopus stolonifer, the common bread mold). Zygomycetes have a characteristic zygosporangium, or sexual spore making […]