Heterologous protein secretion by Candida utilis

Area of Science:

• Biotechnology
• Microbial Engineering
• Protein Production

Background:

• Candida utilis (Torula yeast) is utilized as a food additive and for intracellular molecule production.
• Developing efficient hosts for secreted protein production is crucial for industrial applications.

Purpose of the Study:

• To engineer Candida utilis for the secretion of active proteins, specifically Candida antarctica lipase B (CalB).
• To evaluate the efficacy of different secretion signals and surface display strategies in C. utilis.
• To establish C. utilis as a viable host for recombinant protein secretion.

Main Methods:

• Recombinant C. utilis strains were created using novel expression vectors with nourseothricin resistance (sat1).
• Native and heterologous secretion signals were employed to facilitate CalB secretion.
• CalB was fused to the C. utilis Gas1 cell wall protein for surface display.
• Gene expression was driven by C. utilis promoters, including TDH3 and GXS1.

Main Results:

• Recombinant C. utilis successfully secreted enzymatically active CalB into the growth medium.
• Secreted CalB exhibited minimal N-glycosylation, indicating a simplified post-translational modification.
• Effective surface display of active CalB and β-galactosidase was achieved through Gas1 fusions.
• The developed expression system was functional in multiple yeast species, including Pichia jadinii, Candida albicans, and Saccharomyces cerevisiae.

Conclusions:

• Candida utilis is a promising and versatile host for the secretory and surface display production of active recombinant proteins.
• The developed expression vectors and promoters enable efficient gene expression and protein secretion in C. utilis.
• This work expands the utility of C. utilis in biotechnology and biopharmaceutical production.