A novel gene expression system for Ralstonia eutropha based on the T7 promoter

Area of Science:

• Microbiology
• Molecular Biology
• Biotechnology

Background:

• Ralstonia eutropha is a key model organism for polyhydroxyalkanoates (PHAs) metabolism.
• It is also a promising chassis for heterologous protein expression.
• Current R. eutropha plasmid systems have limitations in expression performance and gene cloning capacity.

Purpose of the Study:

• To develop an improved T7 expression system for Ralstonia eutropha.
• To enhance protein production efficiency and expand synthetic biology applications.

Main Methods:

• Integrated a T7 RNA polymerase gene driven by the P_BAD promoter into the R. eutropha genome.
• Engineered a pBBR1-derived plasmid with a T7 promoter for gene expression.
• Reduced plasmid size by identifying and deleting non-essential replication sequences.

Main Results:

• Successfully established an R. eutropha T7 expression system.
• Reduced the expression plasmid size to 3392 bp, improving electroporation efficiency fourfold.
• Significantly enhanced the expression of red fluorescent protein (RFP).
• Decreased the L-arabinose concentration required for induction twentyfold.

Conclusions:

• The developed R. eutropha T7 expression system offers an efficient platform for protein production.
• This system is well-suited for various synthetic biology applications.
• The optimized plasmid system enhances overall gene expression capabilities in R. eutropha.