Fig. 1

Heterologous glycoprotein expression in different E. coli mutants. a Schematic representation of a series of gene cluster scarless deletion mutants derived from E. coli wild-type strain W3110. b Detection of the expressions of acceptor protein SC4573 and glycoprotein KPO2-SC in W3110 ∆waaL. c Growth curves and viable counts of E. coli wild-type strains and each mutant strain (W3110 ∆waaL, WdlO-d01, WdlO-d02, WdlO-d03, and WdlO-d04). Each strain was inoculated with a seed solution at OD₆₀₀ = 2.0, and LB ratio of 1:100; the viable bacteria were counted by gradient dilution-coated LB plates at OD₆₀₀ = 2.0. d Comparison of KPO2-SC glycoprotein expression in each mutant strain. e Detection of KPO1-SC glycoprotein expression in mutant strain WdlO-d01