3 yeast strains were tested, the first S. cerevisiae well-known for its ability to produce ethanol, but this
yeast is sensitive to osmotic stress; C. Pelliculosa has the ability to grow in media of high osmotic
pressure induced by sugars or salts; and Z. rouxii is well-known for its capacity to grow in rich sugar
environments.The fermentative yeasts S. cerevisiae 522D, Zygosaccharomycesrouxii (IP 2021.92) and
Candida Pelliculosa (IP 820.63) were obtained from the culture collection of the Pasteur Institute
(Paris, France). Stock cultures were maintained on a gelified medium whose composition was (kg m_3):
glucose, 20;peptone, 10; yeast extract, 10; and agar, 10. In all cases, cultures were maintained at 28 _C for
24 h and then stored at 4 _C.