Saturday, March 17, 2018

Not so smooth strawberry smoothie







Several day old strawberry smoothie - N. Carlson
Beware of the several day old strawberry smoothie. This one was was a fuzzy gray when it arrived at the kitchen sink.  I took a tease tape, transferred to a slide with some mounting fluid and examined it under a microscope. The organism has characteristics of both Rhizomucor spp. and Rhizopus spp.  With Rhizopus spp. the sporangiophores start at the same location as the rhizoids (root like structure) individual Rhizopus spp. are connected with a non septate stolon perpendicular to the rhizoids. This is similar to the runners that strawberry plants employ.  With Rhizomucor spp. the sporangiophores branch some distance away from the rhizoids. The branching on this sample is some distance from the rhizoids.

The Rhizomucor spp. sporangiospores are usually under 6 microns in diameter with round to slightly oval spores although some are irregularly shaped.  The sporangiospores in this sample are greater than 6 microns and have the characteristic walnut shell shape of a Rhizopus spp. spore. Both of these organisms can cause strawberries to rot.

Rhizopus spp. line drawing - N. Carlson

Rhizopus spp. or Rhizomucor spp.  - 400x - N. Carlson

The branching at the end is more typical of Rhizomucor spp. - 100x

Close-up of sporangiospores  that are more typical of Rhizopus spp. 


Clinical signs for zygomycete exposure (Mucor spp., Rhizopus spp., or Rhizomucor spp.) infection - 4 min.





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