A Fermentor's Phylogeny

We all appreciate those select few yeasts capable of creating that wonder of wonders, ethanol. And a select few it is, only around 25 of the 1500 yeasts out there are capable of this amazing feat. Among those are the clade Scheffersomyces. Funny enough not a lot of time has been put into detailing exactly how these little moonshine stills are related to each other.
Sure they have been studied to see who is who of making booze, but as much effort has been put into just the who is who part of that statement.
But that is changing.
A study done at the Department of Biological Science of Louisiana University aims to put these little yeasties into thier place on the family tree.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0039128

In this study Hector Urbina and Meredith took samples of yeast from several decaying wood and lignicolous insect guts and put them through a wide series of identification tests. Biochemical Analyses, yup. Morphological characterization, check. And most impressive sounding Multilocus Phylogenetic Analyses, done and done.
And as will happen when a team studies yeasts taken from wild samples(In this case from decomposing trees and insect guts.) New and species have been found. This is not a surprise with few species we have identified in the vast fungal knigdom, but as always it is good to learn more.
Based on the types of wood each strain the proposed species names are: Scheffersomyces virginianus, found the Quercus virginiana, Scheffersomcyces quercinus isolated from Quercus niger, and Scheffersomyces illinoinensis gathered from the substrate species Carya illinoinensis.

 S. quercinus, budding cells (a-b); S. virginianus, budding cells (c-d); and S. illinoinensis, budding cells (e-f)

All three of these new species produce xylose reductase and have been placed in the taxa, which indicates an enhances enzyme efficiency in fermenting D-xylose into good ol' ethanol.
While we have not yet managed to bio engineer any yeasts into taking adavantage of this abundant source of renewable carbon. If we can continue to discover new strains that are eager to make a little fungal white lightning we are sure to keep trying.


Photo and study credit:
 Hector Urbina, Meredith Blackwell
Department of Biological Sciences, Louisiana State University