Spidersilk with unusual strength. Vanillin to make ice-creams taste delicious. Insulin that saves thousands of lives. All these interesting products can be produced in bacteria thanks to synthetic biology and they all have faced a crucial step in their development: what microorganism should be the chosen one?

Currently, two main protagonists take over the stage: the bacteria E. coli and the yeast S. cerevisiae, also known as the Brewer’s yeast. However, there are around 10 actors at play in the synbio arena. And today we want to talk about two of them.

Lactococcus lactis: the first bacteria ever used to treat a human disease

If you have ever tasted Brie, Camembert, Cheddar or Roquefort, you have this bacterium to thank, since it is involved in the early phases of the production of these cheeses. In 2003, this  microbe hit the news for a reason that had nothing to do with cheese. It became the first genetically engineered microorganism used to treat a human disease. A group of researchers modified the genome of this bacterium so it could secrete interleukin 10, a molecule that is helpful to treat inflammatory bowel diseases. This approach was tested on a phase I clinical trial and showed promising results. For the moment, we still have to wait for the definitive treatment.

Bacillus subtilis: flexibility is key

If there was an adjective to describe B. subtilis when looked under the lens of synbio, the main one would be flexible. This bacterium responds well to genetic engineering. It takes up different forms of DNA easily and its genome can be efficiently edited by standard lab techniques. The efforts to transform this bacterium into a useful chassis to insert genes and produce molecules of interest are getting promising results. Researchers have successfully stripped down its genome  and left it with the fundamentals.. When applied to the production of certain molecules, these simplified versions of B. subtilis produce higher yields than non-modified bacteria. This simplification has also additional advantages, as it enhances the capacity of the bacterium to uptake DNA, facilitating the engineering of this organism. When joined with the expansion of the genetic toolbox for B. subtilis with techniques like CRISPR, this microbe is currently on the rise as a multi-purpose host in synbio. That’s why at Rafts4biotech we have chosen it as one of the bacteria we work with.

In addition to all the perks we have said before, both L. lactis and B. subtilis provide a tremendous appeal to biotechs, as they hold the “food- grade” status by the FDA  —meaning that they are either safe for human consumption or that it is okay to come into direct contact with food products. 

If you want to delve deeper into these organisms, read our paper on the matter!