Effects of adenine on the growth and metabolism of Escherichia coli DH5α and its acetate-tolerant mutant DA19

Abstract:

Batch cultures of Escherichia coli DH5α and DA19 in carbon source limited defined media and continuous cultures in nitrogen source limited defined media were performed to compare the metabolism in both strains. DH5α showed improved growth and less acetic acid production after supplementation of adenine, but adenine had little effects on the metabolism of DA19. The proteomic analysis showed that expression of purH was down regulated in DA19 by addition of adenine while was unchanged in DH5α, suggesting that the de novo synthesis ability of purine nucleotide in DH5α was poorer than that in DA19. Supplementation of adenine resulted in enhanced expression of gnd and yddS in DH5α, and thus improved the growth.

Key words:Escherichia coli; adenine; acetic acid; two-dimensional electrophoresis;