E. Coli: An Apt Choice for Recombinant Protein Production

The bio-manufacturing of recombinant proteins requires robust processes that can maximize protein yield from mammalian cell cultures while ensuring the efficacy of these proteins as human therapeutics. Recombinant protein production using mammalian cells offers several advantages over microbial systems in the expression of Escherichia coli. 

Escherichia coli (E. coli) is a bacterial type that is normally located in human intestines and animal guts. It is mostly harmless and helps in keeping the digestive tract healthy. However, some issues may occur, such as diarrhea, if contaminated food or foul water is consumed. 

Researchers’ Choice of Organisms to Produce Recombinant Cell Culture Proteins

While enhancing cell viability, maintaining a healthy culture, and customizing the cell culture in accordance with the needs of an individual, recombinant cell culture plays a highly crucial role. With the increasing need for animal-free supplements in cell culture applications, the recombinant cell culture supplements market is growing.

E. coli is one of the most preferred choices of researchers to produce recombinant proteins. It is used as a cell factory which is well-established and has become the most popular expression platform for recombinant proteins.

Theoretically, the steps for obtaining a recombinant protein are quite simple. These involve taking the gene of interest, cloning it in the expression vector that has been at its disposal, transforming it into the host of choice, inducing it, and then, the protein is ready for purification and characterization.

However, poor growth of the host, inclusion body (IB) formation, protein inactivity, and unavailability of protein are some of the major challenges that come forward down the pipeline of recombinant protein production. 

The growth in the global recombinant cell culture supplements market is expected to be driven by the rising demand for cell culture supplements, increasing investment in life sciences research and development, as well as growing advantages of recombinant supplements over traditional animal-derived supplements. 

The global recombinant cell culture supplements market was estimated at $308.6 million in 2021 and is expected to reach $1.18 billion by 2032, growing at a CAGR of 12.24% during the forecast period 2022-2032.  

Expression Vectors for High-Throughput Protein Expression

The E. coli expression vector possesses the same features as those of other vectors, such as selection marker (e.g., antibiotic resistance), the origin of replication, transcriptional promoter, 5′ untranslated regions (5′UTR), and translation initiation site.

E. coli strains facilitate the expression of proteins containing disulfide bonds or proteins that are encoded by genes containing rare codons and proteins toxic to E. coli. 

A few E. coli strains, such as BL21 and its derivatives, are widely used in recombinant protein production. These strains are efficient in increasing protein stability, containing a chromosomal copy of the T7 ribonucleic acid (T7 RNA) polymerase gene for simple and efficient expression of genes under the control of the T7 promoter. 

Many established companies in cell culture media supplements are entering synergistic activities with emerging companies that are solely focused on recombinant protein production, which is expected to help the global recombinant cell culture supplements market to grow at a faster pace in the years to come. 

Optimization of Recombinant Protein Production in E. Coli 

Even after selecting the plasmid and host, it cannot be predicted if the protein will be obtained in high amounts and in a soluble active form or not. The major limitation of using E. coli for protein expression is its lack of available machinery for post-translational modifications. 

In E. coli, phosphorylation of the targeted molecule (a mouse or human protein) has been achieved by coexpression with human Jun N-terminal kinase 1. Along with it, protein glycosylation is also a major post-translational modification that affects protein stability, distribution, and function. 

Although bacterial N-glycans structurally differ from their eukaryotic counterparts, E. coli enables the production of recombinant glycoproteins in bacteria. Recombinant proteins can be ubiquitinated in E. coli by co-overexpressing the target protein, ubiquitin, and ubiquitin ligases. Therefore, by expressing genes related to the modifications of interest, the targeted proteins can be post-translationally modified in E. coli expression systems. 

In the process of recombinant protein production, cloning methods have been rapidly advancing and can be performed with high efficiency, fidelity, and reliability at a reasonably lower cost. To meet the requirement of developing a highly flexible expression vector, an optimal vector must contain a strong but tuneable promoter and tags with optimized N-terminal codons to facilitate protein expression, solubility, and purification. Large N-terminal tags are also being used to enhance translational initiation and promote solubility. Moreover, new tags are being developed for considerable improvement in protein production. 

The global recombinant cell culture supplements market was dominated by the North America region in 2021. The growth can be attributed to the presence of prominent production of recombinant proteins in the region, as well as the availability of funding and technology for recombinant cell culture supplements. 

Conclusion

Potential strategies to engineer a robust, high-producing cell line growing in a chemically defined media can maximize the production of recombinant proteins with the right glycosylation qualities. E. coli is a suitable host for expressing stably folded, globular proteins from prokaryotes and eukaryotes. Protein expression and purification in E. coli have begun to revolutionize studies in various research fields. 

Where to Learn More

For more information on this market, please see Global Recombinant Cell Culture Supplements Market - Analysis and Forecast, 2022-2023, a detailed 245-page report packed with data and insights covering market segmentation, recent market developments, market demand, drivers and challenges, the competitive landscape, and key players.

About the Publisher: BIS Research is a global market intelligence, research and advisory company that focuses on emerging technology trends that are likely to disrupt the market. Its team includes industry veterans, experts, and analysts with diverse backgrounds in consulting, investment banking, government, and academia.