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Karkaria, B. D.

Publications and source records attributed to Karkaria, B. D..

2 recordsLinked to original sources

Automated design of synthetic microbial communities

In naturally occurring microbial systems, species rarely exist in isolation. There is strong ecological evidence for a positive relationship between species diversity and the functional output of communities. The pervasiveness of these communities in nature highlights that there may be advantages for engineered strains to exist in cocultures as well. Building synthetic microbial communities allows us to create distributed systems that mitigates issues often found in engineering a monoculture, especially when functional complexity is increasing. Here, we demonstrate a methodology for designing robust synthetic communities that use quorum sensing to control amensal bacteriocin interactions in a chemostat environment. We explore model spaces for two and three strain systems, using Bayesian methods to perform model selection, and identify the most robust candidates for producing stable steady state communities. Our findings highlight important interaction motifs that provide stability, and identify requirements for selecting genetic parts and tuning the community composition.

synthetic biology

Killing in response to competition stabilises synthetic microbial consortia

The scale of the biological systems we can engineer is limited by the burden that host cells can bear. Division-of-labour can spread that burden across a community of cells but competitive exclusion inevitably leads to the removal of less fit community members over time. Here, we leverage amensalism and competitive exclusion to stabilise multi-species communities by engineering a strain of Escherichia coli which secretes a toxin in response to competition. We show mathematically and experimentally that such a system can produce stable populations with a composition that is tunable by easily controllable parameters. This is the first system to use competitive exclusion to create a stable two-species consortia and the first to only require the engineering of a single strain.

synthetic biology