Black Yeasts?

[Peter Herman x5495]

In article <33bruj$728 at nermal.cs.uoguelph.ca> jagerrat at uoguelph.ca (John A Gerrath) writes:
>I'm doing a survey of lithic algae here in Ontario and am (of course) 
>picking up a great deal of fungi in the first stage of culturing.  Most 
>of the fungi are pretty easy to peg, but (again of course) some are 
>fairly strange.  Many of these have elicited the response "black 
>yeasts".  What are black yeasts?  Where are they, taxonomically speaking, 
>within the fungi?  Are they fungi?  What is a good source for identifying 
>them?  I'm getting some types exclusively from lichen fruiting bodies, is 
>this odd?   Why/why not?  Please stop me from asking more questions!
>
>Thanks in advance.
>
>John Gerrath,
>jagerrat at uoguelph.ca

The black yeasts are a group of imperfect fungi(in the Hyphomycetes)
which all have dark pigment and blastic conidiogenesis.  The biggie 
in the group is Aureobasidium pullulans (Pullaria pullulans)  There
is a 1962 monograph on the group by Bridge Cooke that is useful in
keying them out.  (W.B. Cook, Mycopathol. Mycol. Appl 17:1-44).

I suspect that your isolates from lichens are on the lichen rather
than the fungal partner in the lichen.  I have done some work on a
specific symbiotic interaction with a gall midge (Lasioptera
ephedricola) in gall formation on Morman tea (Ephedra trifurca).  In
the course of the study, I sampled a variety of plant leaves and
stems as well as soil (though no lichens) and found A. pullulans
nearly everywhere I looked.  The literature lists it as cosmopolitan
and common so this was not a big surprise.  We are currently trying
to do some DNA fingerprinting using Pollack's method (Appl. Environ
Microbiol 58:877-883) in order to resolve some isues on the source
of the inoculum found in the galls (adjacent leaf vs selected by the
insect from a remote source).

Hope this helps

Peter Herman
Biology
New Mexico State Univ
rpeter at nmsu.edu