PAOX1
Introduction
AOX1 promoter is a key promoter in the methylotrophic yeast Pichia pastoris.
Characterization
In order to test the function of PAOX1, we construct "PAOX1-EGFP-terminator" (Figure 1). If PAOX1 is functional, we can test the fluorescence intensity of EGFP in supernatant samples obtained from the culture of recombinant P.pastoris GS115 strain.
Figure 1 Gene circuit of PAOX1-EGFP-terminator
Our results matched the general expected trend (Figure 2). After fermentation experiment in BMMY medium containing 1% methanol. The fluorescence intensity of the samples of recombinant P.pastoris GS115 containing the EGFP gene gradually increased over time, which is in line with literature description[1]. At the same time, we measured the growth curve of the strains.
Figure 2 Fluorescence intensity and OD600 absorbance of samples obtained at different time points from the culture of corresponding recombinant P.pastoris GS115 containing EGFP gene.
Reference
[1] Xuan Y, Zhou X, Zhang W, et al. An upstream activation sequence controls the expression of AOX1 gene in Pichia pastoris[J]. FEMS Yeast Res, 2009,9(8):1271-1282.