Corynebacterium glutamicum is widely used in biotechnology to produce amino acids, proteins, and other biological products. However, genetic systems in this bacterium often show different performance depending on the surrounding DNA sequences, making it difficult to achieve precise and predictable gene expression.

In a study published in Journal of Agricultural and Food Chemistry, a research team led by WANG Peng from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, along with international partners, developed a new genetic strategy to improve the reliability and efficiency of gene expression in Corynebacterium glutamicum, an important industrial microorganism.

Researchers first developed a strategy called "5'-end translationalization." Instead of treating the 5′ untranslated region (5′UTR) as only a regulatory sequence, they redesigned it as a functional element to help control protein production more effectively.

Using this strategy, researchers created a more stable and flexible gene expression system. This system reduces the influence of surrounding genetic sequences and allows different functional elements to operate more independently, improving the predictability of microbial engineering.

Besides, researchers developed a polycistronic design module as part of the strategy to further enhance protein production. Experimental results showed that the system increased the production of recombinant vaccine antigen OmlA by 4.07-fold and boosted the yield of the natural food-grade pigment indigoidine by 7.33-fold.

The strategy was tested in other bacterial hosts including Escherichia coli, demonstrating its potential for wider applications in synthetic biology and microbial manufacturing.

This work provides a new strategy for improving the design of engineered microorganisms, supporting the development of more efficient platforms for producing proteins, food ingredients, and other high-value bioproducts.

Leaderless polycistronic designs. (Image by SUN Manman)