Promoter engineering for the recombinant protein production in prokaryotic systems

Recombinant proteins have an economical value with their utilization in many areas from food industry to pharmaceutical and chemical industry. Therefore, it is of great importance to establish optimum production systems for the proteins of interest. One of the critical steps in protein production is regulation of the gene expression. Promoters are among the key regulatory elements which can directly control the level of recombinant gene expression in a host cell. Thus, a suitable promoter is required for optimum gene expression. Promoter engineering is an innovative approach to find out the best promoter system for the expression of recombinant genes, which influences the overproduction of proteins of interest. In this review, some of the bacterial hosts highly used in recombinant protein production were discussed. Next, the importance of promoters in recombinant gene expression, and promoter engineering for enhanced protein production were described. Utilization of double promoter systems was highlighted as one of the successful techniques in overproduction of recombinant proteins. Increment in the variety and availability of the novel methodologies especially in the synthetic biology is expected to increase the quality and the quantity of recombinant proteins with an economical value.