Part:BBa_K301006
Low Oxygen Level Self-induction Genetic Circuit. NarK promoter
Initially during a fermentation run, DOT levels in the batch fermenter are observed with a gradual decreasing as a result of the E.Coli cells populating in growth. Over time, the DOT in the vessel will fall below 20% in which a critical point in the fermentation is reached as such low concentrations of oxygen will result in cellular death and loss of batch material. This rectified by adding the reagent IPTG (Isopropyl β-D-1-thiogalactopyranoside) in order to induce protein expression. This momentary measurement of low oxygen levels results in what is known in industry as an "Oxygen Spike" and marks the transition of the process from Batch to Fed-Batch in which there is a consistent addition of glycerol to sustain the cells during protein expression. The resultant shift from cellular growth to protein expression can be observed in the immediate increase in OD values subsequent to inoculation.
The NarK promoter (BBa_K239005) can detect the low oxygen level right before oxygen spike during fermentation. Hence initiate transcription of downstream promoter activator, T7 RNA Polymerase, which will then active the T7 promoter. The T7 promoter is followed by another T7 RNAP to enhance the production of promoter activator and the final product, which is represented as RFP in our system.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25INCOMPATIBLE WITH RFC[25]Illegal AgeI site found at 2794
Illegal AgeI site found at 2906 - 1000COMPATIBLE WITH RFC[1000]
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