AUTHOR=Han Jae-Ho , Jung Sang Taek , Oh Min-Kyu 

TITLE=Improved Yield of Recombinant Protein via Flagella Regulator Deletion in Escherichia coli

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.655072

DOI=10.3389/fmicb.2021.655072

ISSN=1664-302X

ABSTRACT=<p>Protein production requires a significant amount of intracellular energy. Eliminating the flagella has been proposed to help <italic>Escherichia coli</italic> improve protein production by reducing energy consumption. In this study, the gene encoding a subunit of FlhC, a master regulator of flagella assembly, was deleted to reduce the expression of flagella-related genes. FlhC knockout in the <italic>ptsG</italic>-deleted strain triggered significant growth retardation with increased ATP levels and a higher NADPH/NADP<sup>+</sup> ratio. Metabolic flux analysis using a <sup>13</sup>C-labeled carbon substrate showed increased fluxes toward the pentose phosphate and tricarboxylic acid cycle pathways in the <italic>flhC</italic>- and <italic>ptsG</italic>-deleted strains. Introduction of a high copy number plasmid or overexpression of the recombinant protein in this strain restored growth rate without increasing glucose consumption. These results suggest that the metabolic burden caused by <italic>flhC</italic> deletion was resolved by recombinant protein production. The recombinant enhanced green fluorescent protein yield per glucose consumption increased 1.81-fold in the <italic>flhC</italic> mutant strain. Thus, our study demonstrates that high-yield production of the recombinant protein was achieved with reduced flagella formation.</p>