Yeasts Occurring in Souring Figs

Abstract

115 yeasts were isolated from Calimyrna, Adriatic and Kadota vars. of figs growing in California. Most of the yeasts isolated were spp. of Saccharomyces or Candida. The more common spp. of Saccharomyces in order of importance were S. cerevisiae, S. tubiformis and S. fragilis, S. carlsbergensis var. polymorphus were also isolated. The genus Candida was represented by species of C. krusei and C. chalmersi. Other organisms isolated were P. kluyveri, P. fermentans, P. belgica, Zygopichia chevalieri, Hanseni-aspora melligeri, Kloeckera lindneri, K. africana, Torulopsis stellata and single cultures of Zygosaccharomyces globi-formis, Hansenula anomala var. sphaerica and a new species, Debaryomyces dekkeri. The sugar tolerance of the organisms isolated was low; most of them growing in 40[degree] but not in 50[degree] Balling fig syrup. The production of volatile and fixed acids was low'' and not sufficient to cause the spoilage termed souring. Evidence was presented to show that adaptive lactase formation occurs in Saccharomyces fragilis.