Size Variation Among Microbial Colonies and Experimental Evidence for a General Principle Coupling the Submolecular to Scale Independent Processes

Microorganisms adapt quickly to resource availability. In constrained environments, population heterogeneity takes an importance that is mostly obviated by cultivation in liquid cultures for which resource competition is global. Recent computational modeling implies that individuals with growth advantages are most successful in structured environments when the absolute growth rate is low or rather, when those with beneficial traits do not compete mainly with ancestors. The focus of this dissertation is to test this hypothesis in a striking case of colony size variation among the fungal pathogen Candida albicans. Chapter 1 reviews the importance of colony size variation among microorganisms. Chapter 2 investigates the phenomenon in three strains of C. albicans: a null mutant for the glutathione-independent glyoxalase, a null mutant for the major adenylyl cyclase, and the wild-type SC5314. Chapter 3 is the first of three independently conceived papers and investigates the relation between (proton) nuclear magnetic resonance properties and fluorescence spectroscopy of 6-acetyl, 2-dimethylaminonaphthalene in a yeast model. The first appendix is the second of three independently conceived papers, reviews the current literature on proton conducting biopolymers, and investigates the underlying mechanism in an example of historical interest: a lysozyme/methylglyoxal complex. The second appendix is the last of three independently conceived papers and investigates the general biophysical hypothesis of chapter 3 and of the first appendix in the context of current progress on the action of the prototypical psychedelic D-Lysergic acid diethylamide