Simoes, Marcus (2026) Conjugation of Plasmids into Photorhabdus laumondii Induces Production of Natural Products. Masters thesis, Concordia University.
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Abstract
The discovery of natural products from the microbial metabolome is essential for the identification of novel bioactive compounds, such as antibiotics. Microbes like bacteria contain all of the necessary biosynthetic machinery to produce natural products, yet only express these genes under conditions of stress, not usually in a lab environment. In this work I demonstrate a new method to increase production of natural products in bacteria: plasmid-induced stress. The metabolic burden induced by plasmid presence in the bacteria Photorhabdus laumondii subsp. laumondii TT01 increases the expression of cryptic biosynthetic genes and the production of multiple natural products. Recombinant protein production from the plasmid and high concentrations of the antibiotic carbenicillin induce additional stress to the bacteria. In plasmid-containing P. laumondii, 19/26 of predicted biosynthetic gene clusters were upregulated and 4/6 known natural products showed increased production. The upregulation of the heat shock and SOS stress responses was observed, as well as an increase in the expression of toxin and virulence genes. Overall, this work will allow for the activation of cryptic biosynthetic gene clusters in diverse bacterial species, without the need for genomic knowledge. The untapped biosynthetic potential of bacteria is vast, and this work will enable the exploration of their metabolome, allowing for the uncovering of new potentially life saving compounds.
| Divisions: | Concordia University > Faculty of Arts and Science > Chemistry and Biochemistry |
|---|---|
| Item Type: | Thesis (Masters) |
| Authors: | Simoes, Marcus |
| Institution: | Concordia University |
| Degree Name: | M.A. Sc. |
| Program: | Chemistry |
| Date: | 10 February 2026 |
| Thesis Supervisor(s): | Findlay, Brandon |
| Keywords: | Microbiology, Molecular Biology, Biochemistry, Natural Products, Antibiotics, Photorhabdus, Bacteria, Plasmids, Conjugation |
| ID Code: | 996818 |
| Deposited By: | Marcus Simoes |
| Deposited On: | 29 Jun 2026 15:09 |
| Last Modified: | 29 Jun 2026 15:09 |
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