| 摘要 |
The present invention refers to a differential and selective culture medium, for the detection of yeasts of the species <i>Zygosaccharomyces bailii</i> and <i>Zygosaccharomyces bisporus</i>, allowing a drastic reduction in the time and work usually involved in the conventional detection of these species. According to the present invention, the detection of <i>Zygosaccharomyces bailii</i> and <i>Zygosaccharomyces bisporus</i> is accomplished with one single test that only requires the preparation, and inoculation of one liquid or solid culture medium. This culture medium is comprised by a base mineral medium supplemented with oligoelements and vitamins, by glucose and formic acid as the only energy and carbon sources, and by an acid-base indicator. The acid-base indicator, particularly bromocresol green, provides the medium with a green coloring that is converted into blue through the action of the above mentioned yeasts. Additionally, the blue color presented by the coloniesis a specific characteristic of these species and can be observed in the medium after 48 to 96 hours of incubation, depending upon the inoculation methodology used. The invention can be used either with previously isolated and purified yeast strains or with cell suspensions of mixed yeast populations containing other yeasts different from <i>Zygosaccharomyces bailii</i> and <i>Zygosaccharomyces bisporus</i>, for the detection of these species in the food industry, namely in wines and other beverages. The medium can also be included in galleries of yeast identification tests. |
