PHA Project Modeling

PHA Project Modeling
We Simulated the whole process from PHB synthesis to lysis gene expression.The results we've got are shown as following.

Expression of PhaR



Figure : the gaussian fit of phaR mRNA content. This curve is drawed according to the experiment data and also the fact that both the transcription of phaR and phaP is regulated by phaR protein.

Expression of PhaP

Figure : Gaussian fit of phaP mRNA curve. The scale of the vertical axis can’t be decided because the experiment can just tell us the relative amount of phaP mRNA amount. But we use the same scale for phaR mRNA content.

Free PhaR Protein

Figure :Free phaR Protein content and the rate for them to bind to PHB granules. Because phaR is continuesly binding to the pHB granules, so there are less free phaR. At the same time, phaP is increasing much faster since less phaP is used to inhibit its transcription. But when there are too much phaP, the phaR will be replaced by phaP on the surface of the granules. What we see in this graph is that the amount of free phaR protein go down first and go up again. The cohesion rate is positive first but becomes negative later.

Concentration of PL repressor

Figure : phaP downstream PL protein level and phaR downstream PL protein level. Cre protein is accumulated very quickly at 16hr and cut the phaR downstream PL DNA sequence, no more PL protein can be produced downstream phaR after 16hr.

Total effect

Figure : Total PL content and PHB content. The PL content is predicted by our theoretical model and the PHB content curve is from experiment data. When the cultivation time is near 50 hours,the total PL  content is only 1/3~1/2 to the initiative amount，because of the sharp down of PL, the lysis gene is transcribed and the e.coli will break down.

The results simulated by MatLab is exactly what expected though wetlab results still waiting to be expected.