Optimization of culturing conditions of recombined Escherichia coli to produce umami octopeptide-containing protein

•Umami peptide is a newly found umami ingredient.•Gene engineering tool was used to expressing disputed umami peptide.•Response surface method was adopted to optimize the expression conditions.

Using synthesized peptides to verify the taste of natural peptides was probably the leading cause for tasting disputes regarding umami peptides. A novel method was developed to prepare the natural peptide which could be used to verify the taste of umami peptide. A controversial octopeptide was selected and gene engineering was used to structure its Escherichia coli. expressing vector. A response surface method was adopted to optimize the expression conditions of the recombinant protein. The results of SDS-PAGE for the recombinant protein indicated that the recombinant expression system was successfully structured. The fitting results of the response surface experiment showed that the OD600 value was the key factor which influenced the expression of the recombinant protein. The optimal culturing process conditions predicted with the fitting model were an OD600 value of 0.5, an IPTG concentration of 0.6 mM, a culturing temperature of 28.75 °C and a culturing time of 5 h.