Temperature management strategy for efficient gene expression in a thermally inducible Escherichia coli/bacteriophage system

Abstract

In a two-phase operation, E. coli containing lambda SNU1 (Q(-)S(-)) in the chromosome is typically cultured at 33 degrees C and cloned gene expression is induced by elevating the temperature. At least 40 degrees C is necessary for complete induction of cloned gene expression; however, temperatures above 40 degrees C have been shown to inhibit cloned gene expression. This suggests that a three-phase operation, which has an induction phase between the growth and production phases, may result in higher gene expression. In this study, optimal temperature management strategies were investigated for the three-phase operation of cloned gene expression in thermally inducible E. col bacteriophage systems. The optimal temperature for the induction phase was determined to be 40 degrees C. When the temperature of the production stage was 33 C, the optimal time period for the induction phase at 40 degrees C was determined to be 60 min. In contrast, when the temperature of the production phase was 37 degrees C, the optimal period for the induction phase at 40 degrees C was 2030 min. When the three-phase temperature and temporal profile were set at a growth phase of 33 degrees C, an induction phase at 40 degrees C for 30 min, and a production phase at 37 degrees C, the highest level of cloned gene expression was achieved. (c) KSBB.