
Synthetic biology envisions a bioengineering
domain for designing new genetic parts and
systems, or redesigning of existing ones.
Until now, the most versatile workhorse of
synthetic biology has been Escherichia coli.
However, there is a need for exploring new
chassis which can be naturally adapted to
unique traits or metabolic pathways.
Lactococcus lactis (L. lactis)
is a ‘Generally Regarded
As Safe’ (GRAS)
organism. It is naturally found in milk products
and is also known to colonize the
human gut.
Unlike E. coli, it does not have an endotoxin
layer, which requires extra measures
for
purification.
Due to its ability to use a wide range of
substrates and tolerance for a
wide range of
conditions (pH, temperature, solvent
concentration), L. lactis serves as an
alternate
bacterial model for metabolic and bioprocess
engineering.

The range of products it can be engineered to
produce include bioplastics,
biofuels,
biopolymers, polyols, and food flavors.
However, the absence of genetic and
regulatory
libraries for this organism make genetic
circuits design and assembly challenging
in
this chassis.
The ability to fine-tune gene expression forms
a cornerstone for the design
and operation of
genetic circuits. This optimization has not
been fully carried out in
non-traditional
chassis like L. lactis.