Nutrient acquisition and metabolic adaptation in the context of Candida albicans virulence Candida albicans is an opportunistic human fungal pathogen. Normally a harmless commensal and part of the microbiota of healthy humans it can cause superficial to life threatening systemic infections under distinct circumstances. Central for this switch is a variety of fungal pathogenicity mechanisms. Amongst them is a remarkable metabolic plasticity which is intricately linked with other central fungal virulence traits like the yeast to hyphae switch. The chief aim of this thesis was to investigate three different aspects of these connections. The first part focused on nutrient acquisition on the example of proline – not only an especially valuable nutrient source for C. albicans but also a potent morphogenetic stimulus. In this study Gnp2 was identified as a specialized proline permease. Further analysis revealed an essential role for this permease for proline induced morphogenesis and fungal resistance against macrophage killing and exposure to reactive oxygen species. In the second part a combinatorial approach of transcriptional and metabolic profiling was utilized to examine the metabolic adaptation of C. albicans to varying degrees of amino acid availability. Thereby a repressive activity of the central amino acid metabolism regulator Stp2 was found on a metabolic gene cluster which is required for the assimilation of hydroxybenzenes. Together with subsequent phenotypical analyses these findings suggested a so far unknown link between the metabolism of aromatic amino acids and hydroxybenzenes in C. albicans. Lastly metabolic changes associated with the fungal switch from yeast to hyphal growth were investigated. A variety of morphotype specific activities of metabolic pathways was identified most notably including a stimulus independent activation of the de novo sphingolipid biosynthesis in C. albicans hyphae. Further by the pharmacological inhibition of this pathway its essential role for proper filamentation was verified.