Taxonomy fun

Phil jorge2 at earthlink.net
Sun Apr 5 18:54:58 EST 1998


Carol Hendrick wrote:
> 
> I wonder if someone with a little more experience in yeast taxonomy
> than I have can give us some insight-- and I hope you'll forgive me if
> I'm a little hypothetical with the details (or if this kind of
> question has already been discussed to death in this group).  We are
> working on forage and forage additives and the things that cause
> preserved silage to spoil when it is exposed to air.  Say that we have
> isolated a strain of yeast and want to be able to give it the
> appropriate name.  We sequence the 18S rRNA and come up with a
> sequence that when checked against GenBank and the RDP database
> matches very well with  both Saccharomyces XXX and Candida YYY, where
> according to the texts, the Candida YYY is the asexual form of the
> Saccharomyces XXX.   After many weeks of plating and waiting on
> several different sporulation media, no spores have been seen.   The
> Biolog yeast database gives a kind of poor match with Candida YYY, the
> Saccharomyces XXX is not in that database.
> 
> So the question is, do you need to see spores before you go ahead and
> call something Saccharomyces?   Somewhere back in my aging
> bacteriologist brain is the idea that Candida is the genus you put
> things in when you don't have spores and don't know where else to put
> them.  But if you have rRNA sequence that tells you it could be
> Saccharomyces, could or should  that influence the ID?
> 
> Would appreciate any thoughts...
> 
> Best regards,
> 
> Carol Hendrick
> hendrickca at phibred.com
> Pioneer Hi-Bred International, Inc.
> Johnston, IA


I'd consider it in the context of more conventional id methods-
physiologic, etc.




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