Sweet gene

The confirmation experiment of Sweet gene.

The confirmation experiment of Sweet gene.

The confirmation experiment of Sweet gene.pdf We get the Sweet gene groE which could help E-coli folding the protein correctly at high temperature from the genome of BL21. Caring this protein would make the host bacteria grow better at high temperature.
Experimental procedure:
Step 1: recover groE and Blank ( E.coli without sweet gene),and shake them at 37℃ for 12 to 16h at 150rpm.
Step 2: measure the OD600 of bacterial liquid .
Step 3: use 50ul bacterial liquid which has been diluted times to coat plates. Set temperature and induced factor (IPTG, 1 mM) control.
Step 4: add 5ul bacterial liquid which has been diluted times to liquid Luria-Bertani medium .Set temperature control. After cultivating for 12 to 16h, measure the OD600 of bacterial liquid.



Fig1. The experimental procedure of Sweet gene’s confirmatory experiment The data of Sweet gene’s confirmation experiment version 1.0


Fig2. The initial OD600 of the groE and Blank

Fig3. The OD600 of the E.coli after 16h

Fig4. The average value of the OD600 of fig 2 The data of Sweet gene’s confirmation experiment version 2.0 The initial OD600 of the g+p ( groE on the backbone of pET32a) and p( plasmid pET32a)

After 4 h, we measure the OD600 of each kind of cell liquid:


Dealing with these data, we got the results as follows:

Averaging the different volume, we have a more visual figure. The Sweet gene plays a powerful role in the temperature struggle.
After 17 hours:


The average of data after 17h:


After 17h, we found a strange phenomenon. The g+p lives better at 42℃ without IPTG, and we don’t know the reason. Besides, the Sweet gene still works in a temperature struggle.

After 45h：

The average of data after 45h:

After 45h, the strange phenomenon became stranger. There was no regularity anymore. The Sweet gene was no longer performing its function.

We still compared the OD600 of one type of bacteria while time elapses. The volume of bacterial liquid is 5 ul.

The volume of bacterial liquid is 10 ul.

The volume of bacterial liquid is 15 ul.

From these figures, we still got the same result as the data above.