Ascomycete yeasts that both ferment and assimilate xylose were reported previously as associates of insects living in woody substrates. Most notable have been reports of Pichia stipitis-like yeasts that are widely associated with the wood-boring beetle, Odontotaenius disjunctus (Coleoptera: Passalidae), in the eastern United States. Our continuing investigation of insect gut yeasts has lead to the discovery of two new xylose-fermenting yeasts that phylogenetic analysis places as sister taxa. The beetle hosts, O. disjunctus and Phrenapates bennetti (Coleoptera: Tenebrionidae), are similar in habitat and appearance, and the presence of similar gut yeasts is an additional common feature between them. Here we describe the new yeast genus Spathaspora, the type species S. passalidarum, and its sister taxon Candida jeffriesii and discuss their natural history, including a comparison with Pichia stipitis, another member of a guild of xylose-fermenting yeasts with similar metabolic traits. In addition a morphologically distinct yeast ascospore type is described for Spathaspora.
Bibliographical noteFunding Information:
We are extremely grateful to Kristin Baum and James Cronin, who helped to capture the beetles in the sweltering heat of a Louisiana August, and Cennet Erbil, Demetra Kandalepas, Jonathan Lo, and Amy Whittington, who helped to culture and characterize the yeasts. Cletus Kurtzman (USDA, Peoria) made available his extensive DNA sequence database for comparisons. GenBank and the NRRL and CBS collections of fungal cultures are gratefully acknowledged. This work was supported in part by National Science Foundation Grants DEB-0072741 and REU supplements to M.B. and Joseph V. McHugh and NSF DEB-0417180 and a REU supplement to M.B., Joseph V. McHugh, and S.-O.S., and the Boyd Professor Fund at LSU. We also acknowledge the use of the DNA sequencing facility supported by NSF Multiuser Equipment Grant (DBI-0400797) to Robb Brumfield.
Copyright 2011 Elsevier B.V., All rights reserved.
- Convergent evolution
- Sexual reproduction
- Wood decomposition