Due to the great biotechnological potential of lignocellulosic waste biomass, studies are intensely aimed at finding microorganisms capable of growing on hydrolysates of lignocellulosic material and developing of biotechnological processes for production of bioethanol and different high-value biochemicals. Accordingly, recent studies have shown that certain Schwanniomyces yeast isolates, such as Schwanniomyces sp. ZIM2980, can grow quite good on acid hydrolysates of lignocellulosic waste material, showing significant biotechnological potential. However, biotechnological potential of some microorganism can be fully exploited only if it can additionally be genetically modified. Therefore, in this thesis, a previously developed process of genetic transformation was used and yeasts Schwanniomyces sp. ZIM2980, Schwanniomyces pseudopolymorphus and Schwanniomyces polymorphus var. africanus were successfully transformed for the first time, as well as the previously successfully transformed yeast Schwanniomyces polymorphus var. polymorphus. All mentioned yeasts have been successfully transformed with non-replicative DNA fragments, and plasmids that can be replicated independently in these species, without the integration in yeast genome, have been identified and can be used to construct replicative expression plasmids.