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Cochrane, R.

Publications and source records attributed to Cochrane, R..

3 recordsLinked to original sources

BRIDGE: A broad-host platform for interkingdom DNA delivery enabling the genetic domestication of phylogenetically diverse yeasts

Efficient DNA delivery remains one of the greatest barriers to engineering non-conventional yeasts, limiting their genetic domestication and exploitation as next-generation microbial cell factories. Here, we present BRIDGE (Bacteria-to-yeast Rapid Interkingdom DNA Gene Exchange), an integrated synthetic biology platform for broad-host interkingdom DNA delivery. BRIDGE is centred on a compact 6-kb Pan/ARS-oriT broad-host BRIDGE vector, enabled by a superconjugative helper plasmid (pSC5). Using BRIDGE, we expanded interkingdom DNA transfer from representatives of four genera accessible using pSC5 alone to ten phylogenetically diverse yeast genera, including Saccharomyces, Maudiozyma, Starmerella, Kazachstania, Yarrowia, Zygosaccharomyces, Lachancea, Kluyveromyces, Pichia and Komagataella. To demonstrate the versatility of BRIDGE, we engineered a 16-kb visual reporter carrying a synthetic five-gene violacein biosynthetic pathway from Chromobacterium violaceum. Individual transcriptional units were first constructed using the YeastFab modular cloning system and subsequently assembled into the complete pathway by single-step in vivo homologous recombination in Saccharomyces cerevisiae, followed by rapid plasmid recovery using the EASY-C platform. The reporter was successfully delivered to all ten yeast genera, demonstrating BRIDGE-mediated transfer of complete multigene synthetic pathways. Robust violacein production was observed across all six Saccharomyces species tested, providing a rapid visual marker for transformant identification, while modest functional pathway expression was also detected in Kazachstania and Kluyveromyces. Successful pathway transfer, albeit without visible pigmentation, was achieved in the remaining genera, indicating that regulatory compatibility, rather than DNA transfer, is the principal determinant of heterologous pathway expression in distantly related yeasts. Collectively, BRIDGE establishes an integrated Design-Build-Recover-Deliver workflow that combines modular in vitro construction of transcriptional units, single-step in vivo assembly of multigene pathways, rapid plasmid recovery using the EASY-C platform and broad-host interkingdom DNA delivery. This versatile framework enables the rapid genetic modification of previously intractable microorganisms, expanding the synthetic biology toolbox for sustainable biomanufacturing and industrial biotechnology.

synthetic biology↗

Engineering Conjugative Plasmids for Inducible Horizontal DNA Transfer

Rapidly developing microbial resistance to existing antimicrobials poses a growing threat to public health and global food security. Current chemical-based treatments target cells by inhibiting growth or metabolic function, but their effectiveness is diminishing. To address the growing antimicrobial resistance crisis, there is an urgent need for innovative therapies. Conjugative plasmids, a natural mechanism of horizontal gene transfer in bacteria, have been repurposed to deliver toxic genetic cargo to recipient cells, showing promise as next-generation antimicrobial agents. However, the ecological risks posed by unintended gene transfer require robust biocontainment strategies. In this study, we developed inducible conjugative plasmids to solve these challenges. Utilizing an arabinose-inducible promoter, we evaluated 13 plasmids with single essential gene deletions, identifying trbC and trbF as strong candidates for stringent regulation. These plasmids demonstrated inducibility in both cis and trans configurations, with induction resulting in up to a 5-log increase in conjugation efficiency compared to uninduced conditions. Although challenges such as reduced conjugation efficiency and promoter leakiness persist, this work establishes a foundation for the controlled transfer of plasmids, paving the way for safer and more effective antimicrobial technologies.

synthetic biology↗

Designer Sinorhizobium meliloti strains and multi-functional vectors for direct inter-kingdom transfer of high G+C content DNA

Storage and manipulation of large DNA fragments is crucial for synthetic biology applications, yet DNA with high G+C content can be unstable in many host organisms. Here, we report the development of Sinorhizobium meliloti as a new universal host that can store DNA, including high G+C content, and mobilize DNA to Escherichia coli, Saccharomyces cerevisiae, and the eukaryotic microalgae Phaeodactylum tricornutum. We deleted the S. meliloti hsdR restriction-system to enable DNA transformation with up to 1.4 x 105 efficiency. Multi-host and multi-functional shuttle vectors (MHS) were constructed and shown to stably replicate in S. meliloti, E. coli, S. cerevisiae, and P. tricornutum, with a copy-number inducible E. coli origin for isolating plasmid DNA. Crucially, we demonstrated that S. meliloti can act as a universal conjugative donor for MHS plasmids with a cargo of at least 62 kb of G+C rich DNA derived from Deinococcus radiodurans.

synthetic biology↗