Source:
Generated By: https://synbiohub.org/public/igem/igem2sbol/1
Created by: Xiang Chen
Date created: 2010-10-26 11:00:00
Date modified: 2015-05-08 01:11:52
Low Oxygen Level Self-induction Genetic Circuit. NarK promoter
| Types | DnaRegion |
| Roles | Device engineered_region |
| Sequences | BBa_K301006_sequence (Version 1) |
Description
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.
Notes
Long part.Source
Constructed.| Access | Instance | Definition |
| public public public public public public | BBa_K239005 BBa_K301005 BBa_K301003 BBa_K301005 BBa_K301003 BBa_I13507 | BBa_K239005 BBa_K301005 BBa_K301003 BBa_K301005 BBa_K301003 BBa_I13507 |
| Sequence Annotation | Location | Component / Role(s) |
| BBa_K239005 BBa_K301005 BBa_K301003 BBa_K301005 BBa_K301003 BBa_I13507 | 1,139 146,1145 1154,1176 1183,2182 2191,2213 2222,3082 | BBa_K239005 BBa_K301005 BBa_K301003 BBa_K301005 BBa_K301003 BBa_I13507 |