Lignocellulosic raw materials are suitable for establishing sustainable bioprocesses as they are renewable and widely available. Non-conventional yeasts such as Scheffersomyces stipitis and Kluyveromyces marxianus stand out as potential working microorganisms for sustainable biochemical production, primarily due to their ability to ferment xylose, which constitutes a large proportion of the dry matter of lignocellulosic raw materials. Therefore, the aim of this study was to investigate whether it is possible to construct producers of these biochemicals by targeted genetic modifications of these yeasts, which do not naturally produce L-lactate and 2,3-butanediol. For the purpose of producing L- lactate, yeast strains S. stipitis and K. marxianus were constructed with the expressed genes ldhL1 and ldhL2, which code for L-lactate dehydrogenase in the bacterium Lactobacillus gasseri. For the production of 2,3-butanediol, the genes alsS and alsD, which code for α-acetolactate synthase and α- acetolactate decarboxylase in the bacterium Bacillus subtilis, were expressed in yeast. In order to increase the yield of L-lactate and 2,3-butanediol, additional modifications aimed at inhibiting competitive metabolic pathways were introduced into the constructed yeast strains K. marxianus. Through a series of experiments, it was established that the producers of L-lactate and 2,3-butanediol yeasts K. marxianus and S. stipitis were successfully constructed. Of the engineered strains, the best producer of L-lactate is the yeast strain K. marxianus with the expressed ldhL1 and ldhL2 genes and the inactivated PDC1 gene, which produces L-lactate with an efficiency of 87 % through glucose fermentation, while the best producer of 2,3-butanediol is the yeast strain K. marxianus that expresses the alsS and alsD genes and produces 2,3-butanediol from glucose with an efficiency of 62 %.