Sunday, December 21, 2014

Mouldy lemon

I found this mouldy lemon lurking at the bottom of our fruit bowl.

It's being attacked by the fungus Penicillium digitatum which will convert it into a spore-coated bag of mush in just a few days. The white areas are a mycelium of rapidly growing fungal hyphae and the bluish-green area marks the zone where spores are being produced in vast numbers behind the advancing fringe of hyphae.

In this macrophoto you can see the invading white mycelium on the left and the green spores on the right.

The fungus very quickly  produces vast numbers of conidiospores, which are pinched off from the tips of the branching hyphae, seen here under the microscope magnified x100.

Under the microscope you can see the conidiospores forming like minute sausages at the hyphal tips, then ......

... becoming rounder once they are released.

You can watch a fascinating time-lapse video of the fungal attack by clicking here


  1. I would imagine it smells very like my nasty lemon smelling topical steroids

    1. Just smelled a little bit musty as this stage