The topic of this thesis has been built on previous work of our group, especially Rieger et al. 2008 and Čepl et al. 2010. We examined and described the regularity of morphogenesis of S. marcescens, morphotype F colonies (from "the fountain", because of a shape it resembles). Typical colony consists of elevated red navel, low non-pigmented ring and again elevated red rim. Structured profile of the colony together with changes in pigmentation of structures during development without need of artificial dying, provides considerable advantage in observation of the morphogenesis. Aims of this thesis were (i) to find other factors that affect the morphogenesis, (ii) to characterize interactions of S. marcescens colonies with other bacterial strains (S. rubidaea and E .coli) and finally (iii) to study the phenomenon of induced resistance to the antibiotics described in (Heal and Parsons, 2002; Lu 2004; Bernier et al. 2011) in our model organisms. (i) Mutual interactions of colonies on the plate indicates that morphogenesis is affected by autocrine signals, which diffuse into the medium and the atmosphere and affect the development of surrounding colonies. We have detected changes of pH of the medium during the development of colonies in their vicinity. At ...