PPET9
Introduction
PET9 promoter is the major ADP/ATP carrier of the mitochondrial inner membrane of Pichia pastoris[1].
Characterization
In order to test the function of PPET9, we construct "PPET9-EGFP-terminator" (Figure 1). If PPET9 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 PPET9-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 decreased during 24-72h, 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] Stadlmayr G, Mecklenbrauker A, Rothmuller M, et al. Identification and characterisation of novel Pichia pastoris promoters for heterologous protein production[J]. J Biotechnol, 2010,150(4):519-529.