Dissertation defence (Biochemistry): MSc Arina Koroleva
MSc Arina Koroleva defends the dissertation in Biochemistry titled “Streptomyces as a Source of Natural Products and Industrial Enzymes” at the University of Turku on 26 September 2025 at 12.00 (University of Turku, Arcanum, Aava auditorium, Arcanuminkuja 1, Turku).
The audience can participate in the defence by remote access: https://echo360.org.uk/section/993bd939-59a4-4370-93a1-2ef3df27e51b/public
Opponent: Professor Gerald Lackner (University of Bayreuth, Germany)
Custos: Professor Mikko Metsä-Ketelä (University of Turku)
Doctoral Dissertation at UTUPub: https://www.utupub.fi/handle/10024/194125
***
Summary of the Doctoral Dissertation:
Streptomyces bacteria are well known for producing compounds that fight infectious diseases and even cancer. They also make enzymes used in industries like food processing, medical diagnostics, and sustainable fuel production. Advances in genome sequencing have shown that Streptomyces have even more hidden potential. Many genes that could produce useful molecules remain silent in the laboratory and are only activated under certain environmental or chemical conditions.
My dissertation explored several strategies to unlock this hidden potential. Using interaction with Saccharomyces cerevisiae yeasts as a natural trigger, I observed broad changes in the Streptomyces genome that led to the production of several antifungal compounds and multiple hydrolytic enzymes. These molecules specifically targeted the yeast cells, altering their cell structure and ultimately causing cell death, which in turn released nutrients that Streptomyces could utilize. These findings provide new insights into how Streptomyces communicates with other microorganisms and how such interactions can induce the production of valuable, previously hidden compounds.
The second part of my research focused on both activating and increasing the production yields of these molecules. I contributed to the development of a method called single-cell mutant ion, which combines random genetic changes with high-throughput screening to rapidly identify bacterial strains with improved production of a target molecule. For example, using this method, my colleagues and I successfully increased the production of the cholesterol oxidase enzyme by more than 20-fold. This technique has direct industrial benefits, as it can significantly increase the efficiency and speed of drug and enzyme manufacturing.
The audience can participate in the defence by remote access: https://echo360.org.uk/section/993bd939-59a4-4370-93a1-2ef3df27e51b/public
Opponent: Professor Gerald Lackner (University of Bayreuth, Germany)
Custos: Professor Mikko Metsä-Ketelä (University of Turku)
Doctoral Dissertation at UTUPub: https://www.utupub.fi/handle/10024/194125
***
Summary of the Doctoral Dissertation:
Streptomyces bacteria are well known for producing compounds that fight infectious diseases and even cancer. They also make enzymes used in industries like food processing, medical diagnostics, and sustainable fuel production. Advances in genome sequencing have shown that Streptomyces have even more hidden potential. Many genes that could produce useful molecules remain silent in the laboratory and are only activated under certain environmental or chemical conditions.
My dissertation explored several strategies to unlock this hidden potential. Using interaction with Saccharomyces cerevisiae yeasts as a natural trigger, I observed broad changes in the Streptomyces genome that led to the production of several antifungal compounds and multiple hydrolytic enzymes. These molecules specifically targeted the yeast cells, altering their cell structure and ultimately causing cell death, which in turn released nutrients that Streptomyces could utilize. These findings provide new insights into how Streptomyces communicates with other microorganisms and how such interactions can induce the production of valuable, previously hidden compounds.
The second part of my research focused on both activating and increasing the production yields of these molecules. I contributed to the development of a method called single-cell mutant ion, which combines random genetic changes with high-throughput screening to rapidly identify bacterial strains with improved production of a target molecule. For example, using this method, my colleagues and I successfully increased the production of the cholesterol oxidase enzyme by more than 20-fold. This technique has direct industrial benefits, as it can significantly increase the efficiency and speed of drug and enzyme manufacturing.
University Communications