My client had purchased a bacterial strain and manufacturing process for a non-proteinogenic amino acid and was manufacturing the amino acid with variable results. I was asked to review their data and make recommendations for improving the process. After comparing the client’s manufacturing data with data from the previous manufacturer, it became clear that the source of most of the variability was the fermentation. I then focused on the details of the fermentation process to further understand the issues.

The client had very little information about the biosynthetic pathway and what they did have was based more on historical speculation than any real data. This made it difficult to recommend any specific bench, pilot or manufacturing fermentation trials to improve the process. A quick literature search revealed that, in fact, parts of the pathway had been studied in detail and there were published sequences for several of the enzymes. A more detailed literature search found several related non-proteinogenic amino acids that had also been studied in some detail. These studies had identified at least some, if not all, of the enzymes in the pathways for these amino acids. Taken together, I assembled a putative biosynthetic pathway and conceptual cellular model for the biosynthesis of the client’s amino acid. This has been used by the client’s process engineers to develop pilot and manufacturing trials to improve the manufacturing process.

Having compiled the literature review, and after comparing the pathway with the pathways of several commercially important proteinogenic amino acids, it was apparent that there was a high likelihood of being able to develop a strain with significantly higher productivity than the current strain. This was presented to the client with recommendations for a strain improvement project. Eventually, the client entered into a strain improvement project and was able to confirm much of the putative biosynthetic pathway that I had proposed.