Abstract: A stable protease A-deficient host strain of Saccharomyces cerevisiae, which undergoes a pseudohyphal-like growth mode when starved for a nitrogen source and is capable of expressing and secrets a heterologous protein when transformed with a secretion vector containing a DNA sequence which encodes the heterologous protein. Also disclosed is a Saccharomyces cerevisiae transformant obtained by transforming such a strain with a secretion vector containing a DNA sequence which encodes a desirable heterologous protein.

Abstract: Microbial strains capable of producing enhanced levels of sphingosine, dihydrosphingosine, phytosphingosine and/or derivatives thereof are disclosed. Additionally, there are disclosed methods based on mutagenesis, or other selection techniques, whereby such strains can be produced. As a preferred example thereof, mutant strains of Pichia are provided that are capable of producing about 50% or more of such compounds than wild type strains.

Abstract: The present invention solves the need for non-toxic forms of selenium which is an essential part of the human diet. This invention provides novel dried-yeast products containing selenium as well as a method of producing the dried yeast products. The method uses selenium having high biological activity but low toxicity. The invention also provides nutritional supplements containing the novel selenium containing dried yeast products and methods of administering these products and supplements to improve human health. The invention also provides a practically non-toxic yeast selenium product having increased intracellular selenium concentrations and methods to reduce tumor cell growth by administration of a selenium yeast product comprising yeast Saccharomyces boulardii sequela PY 31 (ATCC 74366) in combination with chemotherapeutic agents.

Abstract: A strain of bread-mixing yeast for use in obtaining fresh bread-making yeasts: giving at least 100 ml in 2 hours at 30° C. in test A1, preferably at least 110 ml., more preferably at least 150 ml; complying with the following ratio: release ⁢   ⁢ of ⁢   ⁢ CO 2 ⁢   ⁢ in ⁢   ⁢ 48 ⁢   ⁢ hours ⁢   ⁢ at ⁢   ⁢ 8 ⁢ ° ⁢   ⁢   ⁢ C .