Theory 52/Metabolic Engineering
Toxicity Is an Efflux Ratio
The claim
Intermediate toxicity in an engineered pathway is set by the ratio of production rate to efflux capacity rather than by the intermediate's intrinsic toxicity.
01The mechanism
A toxic intermediate is harmless while it is exported as fast as it is made; accumulation begins when production outruns efflux.
02Predictions
- P1Growth should collapse above the ratio.
- P2Intrinsic toxicity alone should mispredict.
03Refutation
Toxicity tracking intrinsic potency would remove the efflux term.