Saccharomyces bulderi sp.nov., a yeast that ferments gluconolactone

An unknown yeast species was isolated from maize silage and was determined to be novel on the basis of morphological and physiological characteristics, nucleotide sequence of domain D1/D2 of LSU rDNA and from its electrophoretic karyotype. The name for the proposed new species is Saccharomyces bulderi Middelhoven, Kurtzman et Vaughan-Martini (type strain CBS 8638, NRRL Y-27203, DBVPG 7127). S. bulderi is closely related to S. barnettii and S. exiguus from which it can be distinguished by having a double vitamin requirement of biotin and thiamine and by no or slow aerobic growth on raffinose, a sugar that on the contrary is fermented rapidly. Gluconolactone is rapidly fermented with ethanol, glycerol and carbon dioxide being the main products.