Killer toxin of Saccharomyces cerevisae Y500-4L active against fleischmann and Itaiquara commercial brands of yeast

The strain Saccharomyces cerevisae Y500-4L, previously selected from the must of alcohol producing plants and showing high fermentative and killer capacities, was characterized according to the interactions between the yeasts and examined for curing and detection of dsRNA plasmids, which code for the killer character. The killer yeast S. cerevisae Y500-4L showed considerable killer activity against the Fleischmann and Itaiquara commercial brands of yeast and also against the standard killer yeast K2 (S. diastaticus NCYC 713), K4 (Candida glabrata NCYC 388) and K11(Torulopsis glabrata ATCC 15126). However S. cerevisae Y500-4L showed sensitivity to the killer toxin produced by the standard killer yeasts K8 (Hansenula anomala NCYC 435), K9(Hansenula mrakii NCYC500), K10(Kluyveromyces drosophilarum NCYC575) and K11(Torulopsis glabrata ATCC 15126). No M-dsRNA plasmid was detected in the S. cerevisae Y500-4L strain and these results suggest that the genetic basis for toxin production is encoded by chromosoma DNA. The strain S.cerevisae Y500-4L was more resistant to the loss of the phenotype killer with cycloheximide and incubation at elevated temperatures (40§C) than the standard killer yeast S. cerevisae K1.

[Studies on brewer's yeast (II). Phlogistic action (author's transl)].

Yeast has a phlogistic effect, and the inflammatory action of 10 brewer's yeast samples fractionated by autolysis and/or destruction of the cell wall was studied in rat hind paw. The yeast samples produced a dose dependent edema when given subcutaneously into the paw. The samples obtained by dissolution or destruction of the cell wall produced the most prominent edema and the phlogistic effect was more potent than commerical yeast powder. Peak of the response was noted 1 hour after injection and thereafter the grade of edema rapidly decreased. The pattern of swelling resembled that by dextran. The edema was partially (less than 40%) inhibited by anti-inflammatory drugs such as aspirin, aminopyrine, phenylbutazone, and indomethacin. Mannan, a main constituent of the yeast cell wall, produced a swelling similar to that observed with yeast samples and this edema was almost completely inhibited by cyprohepatdine, an anti-serotonin drug, but was not inhibited by diphenhydramine, an anti-histamine drug. The results suggest that there is a release of serotonin when brewer's yeast is given subcutaneously, thus producing a phlogistic effect.