Microbial genetics research group

Bacteria evolve rapidly under stress conditions where their growth is inhibited due to unfavorable growth conditions. Under stress conditions, mutations e.g., those leading to the development of antibiotic resistance or biodegradation of various organic xenobiotic compounds, are rapidly emerging. Horizontal gene transfer or the expression of new genes introduced by genetic engineering can also cause stress and an increased frequency of mutations in bacteria. Our group investigates the molecular mechanisms of evolution in bacteria belonging to the genus Pseudomonas. Part of our research is focused on the identification of genes that affect the frequency of mutations in P. putida and P. aeruginosa. We also elucidate the mechanisms of evolution of bacteria that degrade environmental pollutants by performing laboratory evolutionary experiments. In addition, we elucidate the stress responses and adaptation mechanisms that are connected with the construction of new metabolic pathways in P. putida. The results of the research could have applications in industrial biocatalysis, environmental protection and human health.

Research scientists Heili Ilves, Signe Saumaa

Doctoral students Karl Jürgenstein, Tanel Ilmjärv, Mari Tagel

Image used in header: Evolution in a bacterial colony (author: Heili Ilves)

Tagel, M., Ilves, H., Leppik, M., Jürgenstein, K., Remme, J., Kivisaar, M. (2020) Pseudouridines of tRNA anticodon stem-loop have unexpected role in mutagenesis in Pseudomonas sp. Microorganisms. 9(1):25, https://doi.org/10.3390/microorganisms9010025

Kivisaar, M. (2020) Narrative of a versatile and adept species Pseudomonas putida. J. Medical Microbiol. 69:324-338. https://doi.org/10.1099/jmm.0.001137

Mikkel, K., Tagel, M., Ilves, H., Ukkivi, K., Kivisaar, M. (2019) Integration Host Factor IHF facilitates homologous recombination and mutagenic processes in Pseudomonas putida. DNA Repair. https://doi.org/10.1016/j.dnarep.2019.102745

Ukkivi K., Kivisaar, M. (2018). Involvement of transcription-coupled factor Mfd and DNA helicase UvrD in mutational processes in Pseudomonas putida. DNA Repair, 72:18-27. https://doi.org/10.1016/j.dnarep.2018.09.011

Ilmjärv, T., Naanuri, E., Kivisaar, M. (2017). Contribution of increased mutagenesis to the evolution of pollutants-degrading indigenous bacteria. PLoS ONE, e0182484, https://doi.org/doi:10.1371/journal.pone.0182484