MANAGEMENT AND GENETIC CHARACTERIZATION OF AGRICULTURAL AND BIOTECHNOLOGICAL MICROBIAL RESOURCES
Location: Bacterial Foodborne Pathogens & Mycology Research Unit
Title: Diddensiella caesifluorescens gen. nov., sp. nov., a riboflavin-producing yeast species of the family Trichomonascaceae
Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 2, 2012
Publication Date: December 7, 2012
Citation: Gabor, P., Dlauchy, D., Price, N.P., Kurtzman, C.P. 2012. Diddensiella caesifluorescens gen. nov., sp. nov., a riboflavin-producing yeast species of the family Trichomonascaceae. International Journal of Systematic and Evolutionary Microbiology. 2012(62):3081-3087.
Interpretive Summary: This study is part of an international collaboration to discover new yeasts of biotechnological importance, and has focused on isolation of strains from rotted wood because of their potential to transform biomass into biofuels and other biobased products. Strains of the new yeast, named Diddensiella caesifluorescens, were isolated from rotted hardwood from Hungary. Identification and genetic placement of the species among the ascomycete yeasts was from analysis of gene sequences. This species is a member of a relatively small group of yeasts that are able to metabolize recalcitrant chemical molecules. The new species produces the vitamin riboflavin (vitamin B2), but it is not certain whether the amount produced is of commercial interest. Following publication of the description of D. caesifluorescens, this new species will become available to biotechnologists for further study.
Four strains of a novel heterothallic yeast species were isolated from rotten wood collected in or near the Pilis Mountains in Hungary. The strains produced riboflavin in liquid culture. Analysis of gene sequences for the D1/D2 domains of the large subunit nuclear ribosomal RNA (rRNA), as well as analysis of concatenated gene sequences for D1/D2 nuclear large subunit rRNA, translation elongation factor 1-' and RNA polymerase II, subunit Retinol binding protein 1 (RBP1) placed the novel species in a small clade including only two recognized species, Candida santjacobensis and C. transvaalensis, in the family Trichomonascaceae. Both DNA sequence analyses demonstrated that the new species is distinct from all currently recognized teleomorphic yeast genera. The name Diddensiella caesifluorescens is proposed to accommodate the new genus and species. The new genus proposed here can be recognized only from gene sequence analysis, because the characters of its asexual reproduction and ascospore formation are shared by several species of the genera Trichomonascus, Sugiyamaella and Spencermartinsiella. The type and isotype strains of Diddensiella caesifluorescens are NCAIM Y.01949T (NRRL Y-48781T, CBS .....T) and NCAIM Y.01956I (NRRL Y-48782I, CBS .....I), respectively.