From left to right: Agnese Kokina, Juris Kibilds, Zane Ozolina, Janis Liepins

Group leader: Dr.biol. Janis Liepins


Group focuses on the fundamental and applied aspects of yeast nutritional physiology. Currently the group is working to find out mechanisms which are involved in formation of auxotrophic starvation specific phenotype in the budding yeast Saccharomyces cerevisiae.

Purine nucleotide auxotrophy is typical trait of many eukaryotic parasitic organisms. Nucleotide  metabolism is target for several immunosuppressant therapies,  and is also foreseen as potent target for eukaryotic parasite control. Budding yeast Saccharomyces cerevisiae is excellent eukaryotic cell model organism and powerful tool for drug screening.

Understanding mechanism of yeast cell reaction to nucleotide auxotrophy would facilitate yeast application in specific drug screens, developing strategies for control of biotechnological relevant auxotrophic strains, etc.

We have hands on expertise in following methods:

- microbial cultivation (from microcultivation in 96 well plates to laboratory scale fermenters of several litres);

- yeast protein tagging and immunofluorescence;

- yeast stress tolerance assays;

- enzymatic assays (photometric, fluorometric or luminescent detection);

- qPCR.

Group members participate in following projects and activities:

Postdoctoral grant “Molecular mechanisms of purine and pyrimidine auxotrophic starvation in budding yeast“ YEAUX (EU Structural Fund)

“Bacterial intracellular microcompartments as synthetic nanoreactors”  (funded by Mikrotik Ltd, administered by Charity Fund of University of Latvia)

Nacionāla un starptautiska mēroga pasākumu īstenošana izglītojamo talantu attīstībai. SAM 8.3.2. "Palielināt atbalstu vispārējās izglītības iestādēm izglītojamo individuālo kompetenču attīstībai". Projekta numurs:

COST Action CA16120 (European Epitranscriptomics Network)

COST Action CA16112 (Personalized Nutrition in aging society: redox control of major age-related diseases)


Ozolina Z, Kokina A,  Liepins J, 2017. Adenine starvation is signalled through environmental stress response system in budding yeast Saccharomyces cerevisiae Environm Experim Biol 15, 283 - 286

Pentjuss, A., Stalidzans, E., Liepins, J., Kokina, A., Martynova, J., Zikmanis, P., Mozga, I., Scherbaka, R., Hartman, H., Poolman, M.G., Fell, D.A., Vigants, A., (2017). Model-based biotechnological potential analysis of Kluyveromyces marxianus central metabolism. J. Ind. Microbiol. Biotechnol. Vol. 44, p. 1177–1190.

Martynova J., Kokina A, Liepins J, Scerbaka R, Vigants A, 2016. Effects of acetate on Kluyveromyces marxianus DSM 5422 growth and metabolism. Appl. Microb. and Biotechn., 100 (10), 4585-94 [0]

Liepins J, Kovačova E, Shvirksts K, Grube M, Rapoport A, Kogan G. 2015. Drying enhances immunoactivity of spent brewer's yeast cell wall β-D-glucans. J. Biotechnol. 206: 12-6.  [2]

Rungis, D.E., Voronova, A., Kokina, A., Veinberga, I., Skrabule, I. and Rostoks, N. 2015. Assessment of genetic diversity and relatedness in the Latvian potato genetic resources collection by DArT genotyping. Plant Genetic Resources, pp.1-7.

Kuka J, Liepinsh E, Makrecka-Kuka M, Liepins J, Cirule H, Gustina D, Loza E, Zharkova-Malkova O, Grinberga S, Pugovics O, Dambrova M, 2014. Suppression of intestinal microbiota-dependent production of pro-atherogenic trimethylamine N-oxide by shifting L-carnitine microbial degradation. Life. Sci. 117(2): 84-92 [12]

Kokina A, Kibilds J, Liepins J, 2014. Adenine auxotrophy – be aware. Some effects of adenine auxotrophy in Saccharomyces cerevisiae strain W303-1A, FEMS Yeast Res.,  14(5): 697-707 [3]

Makrecka M, Svalbe B, Volska K, Sevostjanovs E, Liepins J, Grinberga S, Pugovics O, Liepinsh E, Dambrova M, 2014. Mildronate, the inhibitor of L-carnitine transport, induces brain mitochondrial uncoupling and protects against anoxia-reoxygenation, Eur. J. Pharmacol., 723: 55-61 [6]

Grube M, Dimanta I, Gavare M, Strazdina I, Liepins J, Juhna T, Kalnenieks U, 2013. Hydrogen-producing Escherichia coli strains, overexpressing lactose permease: FT-IR analysis of the lactose-induced stress, Biotechnol. Appl. Biochem., 61(2): 111-7 [1]

Smits K, Liepins J, Gavare M, Patmalnieks A, Gruduls A, Jankovica Dz, 2012. Zirconia nanocrystals as submicron level biological label, IOP Conf. Ser.: Mater. Sci. Eng. 38, 012050 [2]

Rapoport, A., Borovikova, D., Kokina, A., Patmalnieks, A., Polyak, N., Pavlovska, I., Mezinskis, G. and Dekhtyar, Y., 2011. Immobilisation of yeast cells on the surface of hydroxyapatite ceramics. Process Biochemistry, 46(3), pp.665-670.

Brusbardis V, Liepins J, 2010. Mathematical modeling of glycerol cycle in baker’s yeast, Research for Rural Development, Annual 16th, International Scientific Conference Proceedings, Jelgava, LLU, 214 – 220, ISSN 1691-4031 [0]

Kokina, A. and Rostoks, N., 2008, January. Genome-Wide and Mla Locus-Specific Characterisation of Latvian Barley Varieties. In Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. (Vol. 62, No. 3, pp. 103-109).

Kokina, A., Legzdina, L., Berzina, I., Bleidere, M., Rashal, I., Rostoks, N. and Šterne, D., 2008. Molecular marker-based characterization of barley powdery mildew Mlo resistance locus in European varieties and breeding lines. Agronomijas Vēstis, (11), pp.77-83.

Liepins J, Kuorelahti S, Penttilä M, Richard P, 2006. Enzymes for the NADPH-dependent reduction of dihydroxyacetone and D-glyceraldehyde and L-glyceraldehyde in the mould Hypocrea jecorina. FEBS J. 2006, 273(18): 4229-35. [23]


Conference thesis

Liepins J, Kokina A, 2014. Nutritional effects on baker’s yeast desiccation tolerance. CBM2014, Tartu, Estonia, 16- 19.10

Kokina A, Kibilds J, Liepins J,  2013. Some adenine auxotrophy effects in yeast Saccharomyces cerevisiae, 26th International Conference on Yeast Genetics and Molecular Biology, Frankfurt, Germany, 29. August- 04. September

Liepins J , Gavare M, Kokina A, Grube M, Smits K, 2012. FT-IR based Saccharomyces cerevisiae biomass quantification and it’s application in ZrO2 nanoparticle toxicity studies, proof of principle 1st congress of Baltic Microbiologists (CBM2012), Riga, Latvia, 31.October-3.November,

Kokina A, Liepins J, 2012. Role of ade8 mutation in stress resistance of yeast Saccharomyces cerevisiae CEN.PK strain background, 22nd IUBMB Congress/37th FEBS kongress, Sevilia Spain, 04- 09. September



VTT Biotechnology (Finland),

University of Tartu (Estonia)

University of Stockholm (Sweden)


Institute of Solid State Physics

Institute of Organic Synthesis of Latvia

TEVA Latvia