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Updated: Jun 3, 2026

High-throughput Yeast Plasmid Overexpression Screen
Published on: July 27, 2011
Reliable high-throughput approach for screening of engineered constitutive promoters in the yeast Pichia pastoris
1State Key Laboratory of Bioreactor Engineering, East China University of Science & Technology, Shanghai, China.
Aims:
To develop a reliable and sensitive high-throughput approach for the screening of engineered constitutive promoters in the yeast Pichia pastoris.
Methods And Results:
The yeast-enhanced green fluorescent protein (yEGFP) was used as the reporter to monitor the promoter strength. After eliminating the interfering components (yeast extract and tryptone) with fluorescence signal from the medium, a high-throughput screening approach was established and optimized to obtain a low standard deviation of cell density (6.9%) and fluorescence (7.4%) in 48-deep-well microplates. Then, 300 clones containing GAP promoter (P(GAP)) variants were screened, exhibiting a wide range in fluorescent intensity from about 8% to 218% of that obtained with P(GAP). Six representative clones with unique promoter sequence were picked for further characterization. A good correlation between yEGFP fluorescence in microplates and shake flasks was observed. Furthermore, the high correlation between fluorescence and transcript levels confirmed that expression was transcriptionally controlled.
Conclusions:
We developed a reliable high-throughput screening approach that can be used to select engineered constitutive promoters of varying strengths.
Significance And Impact Of The Study:
This approach is expected to accelerate the selection of constitutive promoters in P. pastoris and can also be applied for the screening of other constitutive expression clones.

