Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2003
Publication Date: 6/1/2003
Citation: Gimenez-Jurado, G., Kurtzman, C.P., Starmer, W.T., Spencer-Martins, I. 2003. Metschnikowia vanudenii sp. nov. and Metschnikowia lachancei sp. nov., from flowers and associated insects in North America. International Journal of Systematic and Evolutionary Microbiology. 53:1665-1670. Interpretive Summary: Species of the yeast genus Metschnikowia are found worldwide and often isolated from the flowers of plants. These yeasts are of interest to agriculture because they are not pathogenic to humans and some of the species are effective biocontrol agents of fruit storage rot fungi. In this study, two new species of Metschnikowia are described. They were recognized as new from comparison of their gene sequences, which is the most effective means for identifying yeasts. The new species are phylogenetically near known biocontrol species and will be tested for their effectiveness as biocontrol agents
Technical Abstract: Two new species were discovered among isolates from nectaries and associated muscoid flies of flowers in North America. Metschnikowia vanudenii is heterothallic with both haploid and diploid strains. Like its close relative, the nectar species Metschnikowia gruessii, it produces "airplane" or cross formations, ovoid chlamydospores and ellipsoidopedunculate asci with two acicular ascospores. Low nuclear DNA sequence complementarity (13%) between M. gruessii and M. vanudenii supports the separation of these sister taxa. Metschnikowia lachancei was first recovered from Asclepias syriaca in USA, and is easily distinguished from other Metschnikowia species by its unique ascus and ascospore morphology. The combination of club-shaped asci, bearing 1-2 thick clavate ascospores, and low DNA relatedness (0-23%) with closely related species (M. gruessii, M. vanudenii and M. reukaufii) substantiates the proposal of a new species. The phylogenetic positions of the proposed species were determined by sequence analysis of the D1/D2 domain of 26S rDNA. Both species fit well in the Metschnikowia clade and this data support the description of the two novel species. The designated type strains are: M. vanudenii PYCC 4650 (CBS 9134, NRRL Y-27243, UWO (PS)86A4.1), and M. lachancei PYCC 4605 (CBS 9131, NRRL Y-27242, UWO (PS)7ASB2.3).