Tag: <span>microbial fermentation</span>

Stirred tank single-use bioreactors (SUBs) have been widely adopted for production of biopharmaceuticals such as monoclonal antibodies in mammalian cell culture. However, they are seldom used for commercial production of biologics with microbial fermentation. SUBs offer time-saving advantages because they do not require significant downtime for cleaning and sterilization, so finding a SUB that can perform well with high cell density microbial fermentation processes has the potential to increase the number of production runs. Therefore, for this study, a His-tagged protease inhibitor was chosen as a model protein to demonstrate that the Sartorius Biostat STR¬ģ MO, a SUB recently developed for microbial fermentation, is suited for recombinant protein production by high cell density Escherichia coli fermentation processes.

At 50 L scale, the SUB achieved good process control and allowed an oxygen uptake rate (OUR) of up to 240 mmoles/L/h. The fermentation runs produced up to 5.8 g/L of the soluble recombinant protein and a dry cell weight of >60 g/L at the end of fermentation. Additionally, the SUB showed a similar fermentation profile when compared with data from parallel runs in 15 L sterilise-in-place (SIP) vessels using identical media and process parameters. This study indicates that with a minimum investment of capital resources, stirred tank SUBs could be used in pilot-scale manufacturing with high cell density microbial fermentations to potentially shorten the timelines and costs of advancing therapeutic proteins to clinic.


Microbial fermentation is used to produce such products as therapeutic proteins, antibiotics, hormones, enzymes, amino acids, blood ­substitutes and ­alcohol. These products may be expressed by the microbial cells themselves, expressed intracellularly in the cytoplasm or, in the case of bacterial cells, in the periplasmic material. Before any intracellularly-produced molecules can be used and further purified, the cells (i.e., E. coli) must be concentrated and set in an ­appropriate buffer (cell washing) before being lysed. Then after lysis, molecules of ­interest have to be separated from the ­parent cells and then clarified to remove ­cellular debris and other contaminants. Depending on the process used, additional clarification steps may be necessary…

Biologics Production