Studies on Toddy Yeast

SUMMARY

1.	Fifteen cultures of yeast were isolated from the toddy obtained from palmyra palm, Borassus flabellifer.
2.	Eight of the cultures belonged to Schizosaccharomyces pombe Lindner, six to Saccharomyces chevalieri Guilliermond and one to Saccharomycodes ludwigii Hansen.
3.	Schizosaccharomyces pombe strains were deficient in the synthesis of inositol and poor or subnormal in the synthesis of nicotinic acid. Six of them were completely or almost completely deficient in the synthesis of pantothenic acid. The remaining two strains synthesised pantothenic acid but were deficient in biotin.
4.	One of the strains of Schizosaccharomyces pombe analysed for its mating system proved to be homothallic. It also proved to be homozygous for the genes concerned in the synthesis of riboflavin, thiamin, biotin, and pyridoxin.
5.	All the six strains of Saccharomyces chevalieri fermented galactose in 48 hours. Analysis of single ascospore cultures from two of them showed that they were heterozygous for the fermentation of this sugar.
6.	A case of mutation from maltose non-fermenter allele to the fermenter allele was recorded in one of the strains of Saccharomyces chevalieri.
7.	All the six strains of Saccharomyces chevalieri proved to be autotrophic with respect to the synthesis of various members of vitamin B complex. Two of the strains were homozygous for the synthesis of riboflavin, thiamin, nicotinic acid and pyridoxin. Synthesis of biotin in one of the strains was found to be controlled by a single locus for which it was heterozygous. Two strains of S. chevalieri proved to be homothallic and one seemed to be basically heterothallic.
8.	The strain of Saccharomycodes ludwigii isolated, failed to ferment raffinose.