Skip to main content

The first auxotrophic mutant of Zygosaccharomyces bailii for recombinant productions: a road to practical applications


The yeast Zygosaccharomyces bailii belongs to the so-called group of non-conventional yeasts, poorly studied in the past. For this reason, up to now there is no deep knowledge regarding its physiology, genetics and molecular biology, and its genetic manipulation is not easy. Only recently this yeast attracted the attention of the scientific community due to its characteristics of stress resistance, particularly to acidic environments. Our group is working on the construction and improvement of molecular tools for an exploitation of Z. bailii as a new host system for biotechnological applications.


In spite of the good results already obtained for the production and secretion of different proteins, a great limit was represented by the lack of an auxotrophic mutant and of a reproducible protocol for targeted gene deletion in this yeast. Here we show the strategy used to obtain the first Z. bailii auxotrophic mutant (Zbleu 2 strain) and the consequent exploitation of said mutant for heterologous protein production and for metabolic engineering applications. The data obtained with the new strain showed a great improvement of production, mainly related to higher plasmid stability, if compared with the wild type strain transformed with similar plasmid but selecting for an antibiotic resistance. In addition, and once more exploiting the leu2 auxotrophy, we are developing a strategy for high copy number replication of an heterologous gene of interest.


According to our knowledge, this is the first example of an auxotrophic Z. bailii strain exploited for recombinant productions. It represents a small but necessary step to develop this host for biotechnological applications, that already resulted in significant improvement in the productions of interest.

Author information

Authors and Affiliations


Rights and permissions

Open Access This article is published under license to BioMed Central Ltd. This is an Open Access article is distributed under the terms of the Creative Commons Attribution 2.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and permissions

About this article

Cite this article

Branduardi, P., Dato, L., Riboldi, L. et al. The first auxotrophic mutant of Zygosaccharomyces bailii for recombinant productions: a road to practical applications. Microb Cell Fact 5 (Suppl 1), P67 (2006).

Download citation

  • Published:

  • DOI: