- Volume 73, Issue 2, 1972

SUMMARY: Mannophosphoinositides appear to be widespread among the Actinomycetales. Besides the well-known mycobacterial source, they are also present in streptomyces, microbispora (Kataoka & Nojima, 1967; Tabaud, Tisnovska & Vilkas, 1971), nocardias (Yano, Furukawa & Kusunose, 1969) and corynebacteria (Brennan & Lehane, 1971) and a related phosphorus-free mannoinositide is prominent in propionibacteria (Prottey & Ballou, 1968; Shaw & Dinglinger, 1969). Prompted by the unusual observation of a monomannophosphoinositide in Corynebacterium aquaticum (Khuller & Brennan, 1972) we have examined in more detail three species of Nocardia, and find that mannophosphoinositides, which are always of the dimannosyl type, are barely evident in Nocardia polychromogenes, whereas in N. coeliaca, they are among the most obvious phospholipids. Glucose-containing phospholipids and glycolipids are always prominent.

SUMMARY: Numerical analysis of the 41 species currently recognized in the genus Saccharomyces indicated that only 23 clusters were sufficiently different, at less than 90% matching of 58 characters, to be classified as separate species. These species belonged to four main divisions of the genus, mutually related at 70 to 75% matching: Saccharomyces cerevisiae group (twelve species), S. exiguusgroup (seven species), S. florentinus group (three species) and S. rouxii. By similar analysis of the genus Kluyveromyces, three groups were recognized; the first, of twelve species, was associated with Kluyveromyces lactis, which, related at 70% to the four groups of Saccharomyces, may be regarded as a fifth group of that genus. The second group of Kluyveromyces is a single species, K. veronae, which is related to the S. cerevisiae group. The third group of Kluyveromyces, five former species related to K. africanus, is closely related to S. exiguus. The genera Saccharomyces and Kluyveromyces overlap and it is proposed that they be regarded as a single genus, Saccharomyces. In the combined genus there are 34 species, assessed at 90% matching coefficient. A list of proposed synonyms is presented, with modified standard descriptions of those species in which the synonyms are merged.

The advantages of serological identification over a scheme based on fermentation and assimilation are discussed; yeast isolates may be allocated rapidly to one of the major taxonomic groups by agglutination and examination of morphology.

Saccharomyces rouxii characteristically reacted with serum A, and S. exiguus group usually with serum D, although occasionally also with sera A or B. The groups of species associated with Kluyveromyces lactis, S. cerevisiae and S. florentinus were antigenically heterogeneous, but were distinguished by morphology of the cells.