Lee metbolic eng synthetic bio BME 162 GuestLecture Apr2_2012

E glutamine and ketoglutarate levels transmits signal

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: /gDW/hr 2.3 mmol/gDW/hr[6] 2,3-Butanediol Non-native Uniform probabilistic search Exhaustive search Literature 9 9 NA 0.11 g/g glucose 0.11 g/g glucose 0.31 g/g glucose[40] Fatty acid ethyl ester4 Non-native Uniform probabilistic search Exhaustive search Literature 19 1092 NA 3.58 mmol/gDW/hr 3.58 mmol/gDW/hr 647 mg/l[37] (0.34 g/g glucose) Fatty acid methyl ester5 Non-native Uniform probabilistic search Exhaustive search Literature 45 1353 NA 1.07 mmol/gDW/hr 1.08 mmol/gDW/hr 0.3 g/gDW[15] 4/2/12 BME 162 Guest Lecture 37 Balancing Cell Growth Using Dynamic Control Model system: lycopene production in E. coli Promoter Signaling molecule Target pathway Farmer and Liao, Nat Biotechnol. 2000 May;18(5):533-7. 4/2/12 BME 162 Guest Lecture 38 Signal and Sensor •  Acetyl phosphate (ACP) –  Indicates glucose availability •  Increasing levels of ACP can be good indicator of excess glucose flux –  Regulator of many na0ve regulons •  Ntr regulon –  Adapts the cell to nitrogen ­deficient condi0ons –  Insignificant role under bioreactor condi0ons (nitrogen ­rich) –  NRII: sensor in na0ve Ntr regulon •  Senses nitrogen status, i.e. glutamine and α ­ketoglutarate levels •  Transmits signal to the response regulator NRI through phosphoryla0on –  NRI ­P: ac0vates transcrip0on from glnAp2 promoter (‘valve’) –  In the absence of NRII, NRI can sense ACP level 4/2/12 BME 162 Guest Lecture 39 Characteriza0on of Dynamic Controller Engineered control loop (A): delete NRII and allow NRI to both sense ACP and control gene expression Wild-type Engineered cell Static induction 4/2/12 BME 162 Guest Lecture 40 Dynamic Control of Mul0copy Gene Expression   Control (‘static’) tac promoter   Engineered adaptable promoter system  No plasmid 4/2/12 BME 162 Guest Lecture 41 Metabolic Control Engineering of Lycopene Produc0on Rerouted carbon flux Control circuits Controls balance between pyruvate and G3P (precursors for lycopene) 4/2/12 BME 162 Guest Lecture 42 Dynamic control improves lycopene produc0on  Wild-type control  Lycopene genes + tac promoter for idi  Lycopene genes + adaptable promoter for idi Lycopene genes + tac promoter for idi and pps  Lycopene genes + adaptable promoter for idi and pps 4/2/12 BME 162 Guest Lecture 43 Modularity of Na0ve Metab...
View Full Document

Ask a homework question - tutors are online