Difference between revisions of "Part:BBa K2963033"
| Line 22: | Line 22: | ||
Figure 2. we tested the enzyme activity of the racemase in cells. The enzyme activity under the control of one <i>lacO</i> is higher than that with two <i>lacO</i>s. | Figure 2. we tested the enzyme activity of the racemase in cells. The enzyme activity under the control of one <i>lacO</i> is higher than that with two <i>lacO</i>s. | ||
| + | |||
| + | ===References=== | ||
| + | |||
| + | 1.Keitarou K. Roles and regulation of the glutamate racemase isogenes, racE and yrpC, in Bacillus subtilis[J]. Microbiology, 2004, 9(150): 2911-2920. | ||
| + | |||
| + | 2. Feng Jiang, Gaofu Qi, Zhixia Ji. Expression of glr gene encoding glutamate racemase in Bacillus licheniformis WX-02 and its regulatory effects on synthesis of poly-γ-glutamic acid[J]. Biotechnology Letters, 2011, 33: 1837-1840. | ||
| + | |||
<!-- Add more about the biology of is part here. | <!-- Add more about the biology of is part here. | ||
Latest revision as of 11:35, 20 October 2019
Ptac(two lacOs)-racE- Producing γ-PGA with different D/L monomer ratio
Our project used this part to produce γ-PGA with different D/L glutamate monomer ratios.This part contains the racE gene, which was under the control of a modified tac promoter with another additional operator gene (lacO). We used racemase activity data and real-time PCR data to characterize and compare the different expression intensities of racE gene using different structures of tac promoters.
Usage and Biology
The racE gene is derived from Bacillus subtilis. This gene encodes a racemase which can converts L-glutamic acid to D-glutamate.
Characterization
We used real-time quantitative PCR and enzyme activity assay to compare the different expressions of racE gene under the control of tac promoter containing different numbers of operator genes in Corynebacterium glutamicum. The results were shown in Figure 1. The expression level of the racE gene at 8 h, 16 h, 24 h decreased by 29.99%, 58.86% and 62.34% respectively. The results showed that the expression intensity of racE was effectively reduced at each transcriptional stage by the tandem of two lacOs compared to one lacO. At the same time, we tested the activity of the racemase in cells. The enzyme activity under the control of one lacO is higher than that with two lacOs. The data is shown in Figure 2.
Figure1
Figure 1. The expression level of the racemase gene racE at 8 h, 16 h, 24 h decreased by 29.99%, 58.86% and 62.34% respectively. The results show that the expression intensity of racE was effectively reduced at each transcriptional stage by the tandem of two lacOs compared to one lacO.
Figure2
Figure 2. we tested the enzyme activity of the racemase in cells. The enzyme activity under the control of one lacO is higher than that with two lacOs.
References
1.Keitarou K. Roles and regulation of the glutamate racemase isogenes, racE and yrpC, in Bacillus subtilis[J]. Microbiology, 2004, 9(150): 2911-2920.
2. Feng Jiang, Gaofu Qi, Zhixia Ji. Expression of glr gene encoding glutamate racemase in Bacillus licheniformis WX-02 and its regulatory effects on synthesis of poly-γ-glutamic acid[J]. Biotechnology Letters, 2011, 33: 1837-1840.