The genetic control of the two types of mannan produced by Saccharomyces cerevisiae

DNA sequence similarity, cell wall mannans and physiological characteristics in some strains of Candida utilis, Hansenula jadinii and Hansenula petersonii

The physiological characteristics, proton magnetic resonance spectra of cell wall mannans, DNA base composition and DNA sequence similarity of some strains of Candida utilis, Hansenula jadinii and Hansenula petersonii were examined. It was found that C. utilis was not distinguishable from H. jadinii by any of these criteria. These findings show the close genetic relationship between C. utilis and its perfect form H. jadinii. In contrast, H. petersonii was found to differ from C. utilis and H. jadinii on account of insignificant DNA reassociation as well as a number of other properties.

DNA base composition of species of the genus Saccharomyces

DNA base compositions (GC content) of Saccharomyces species are reported and discussed. Several amendments of the four groups given by van der Walt are suggested, viz. the transfer of S. kluyveri to group 1, and of S. eupagycus, S. cidri, S. montanus, S. microellipsodes and S. florentinus to group 2. The synonomy of S. amurcae and S. cidri is suggested. The DNA base compositions revealed two possible pairs of sibling species: S. elegans and S. bailii, with a difference in GC content of 4.1%; S. dairensis and S. servazzii with a difference in GC content of ca. 3%. S. mrakii had a GC content of 47.3-48.5% the highest encountered in this genus and similar to that of Kluyveromyces thermotolerans.