The following thesis is a composite of two separate research projects which were undertaken by the author for the award of an MRes in Molecular and Cellular Biology within the School of Biosciences at the University of Birmingham. Part one of this thesis will detail the first research project which sought to characterise the contribution of the enzyme phospholipase B to the intercellular lifecycle employed by the pathogenic fungus Cryptococcus neoformans which has the ability to survive within the phagolysosome of immune cell macrophages. This project used cell culture and microscopy techniques as well as whole cell lipidomic analysis and found that many aspects of Cryptococcus neoformans parasitism of macrophages are modified by phospholipase B activity. Part two of this details the second project which examined the predatory bacteria Bdellovibrio bacteriovorous. This bacterium has a unique lifecycle which involves predation of other gram negative bacteria resulting in prey cell invasion and an interperiplasmic growth and replication phase. This project sought to purify and characterize two B. bacteriovorous C-di-GMP modifying enzymes – Bd2325 and Bd1971. Herein we report the first putative analyses of these proteins.