(56d) Peptide-Based Communication Platform for Interspecies Communication

Traditionally,
industrial processes requiring bacteria have used a single organism. However, future
processes are likely to take advantage of the many advantages available that
come from utilize microbial consortia. In order to control interactions and complex
dynamics required for these cells to work together, it is important for
engineers and synthetic biologists to create robust communication pathways
between biotechnologically relevant species.  Escherichia
coli and Bacillus megaterium
are two such bacterial species that have proven themselves useful in industry
in the past. Here we present a synthetic communication pathway between the two
using a heterologous quorum sensing (QS) mechanism taken from Staphylococcus aureus.
The QS system of S. aureus
is composed of four genes making up the accessory gene regulator (agr) locus. The agrB and agrD genes, along with a Type I Signal Peptidase, produce
and secrete the signaling molecule termed Autoinducing
Peptide (AIP). The agrC
and agrA
genes encode a two component signaling cascade that leads to up-regulation of
all four QS genes. We have engineered an E.
coli strain that is able to produce and secrete mature AIP into the cell
supernatant. Furthermore, introducing this supernatant to our engineered B. megaterium
cultures effectively induces target gene expression. We anticipate that our communication
system, when combined with successful co-culture systems, will be a key
technology for the implementation of synthetic consortia for bioprocessing
applications.