ABSTRACT
With the yeast biotechnology base already in existence, it is safe to predict that yeast will continue to play a major role in industry for many more years to come. With the knowledge of genetic manipulation of yeast, however, the emphasis on industrial use of yeast will, the author believe, gradually shift from traditional biotechnology to the "new" biotechnology. Although the most commonly used yeast Saccharomyces cerevisiae is a simple unicellular organism, it has many of the characteristics of a complex, highly sophisticated eukaryotic system. Plasmid propagation and maintenance can be highly strain specific. Use of a diploid or a polyploid, rather than a haploid, could be critical for a large-scale fermentation process. While modem strain selection in these cases may be limited to the improvement in efficiencies of the processes, it is generally not crucial to the end product, with some exceptions (e.g., off-flavor removal).
