Robert’s main field of inquiry throughout his career has been in porphyrin biosynthesis and metabolism, specifically the biochemistry of heme and chlorophyll biosynthesis in bacteria, plants and algae. His team was the first to define the structure of a magnesium chelatase subunit. The current focus of research efforts relate to the mechanism of metal ion insertion into protoporphyrin IX to make heme or magnesium protoporphyrin IX, and the regulation of these two competing reactions. He is also interested in the regulation and synthesis of aminolevulinic acid, which is the universal precursor of all tetrapyrroles. Together with Professor Min Chen at the University of Sydney, he is working on characterising Halomicronema hongdechloris, the chlorophyll f synthesizing cyanobacteria that they discovered in stomatolites off Shark Bay, WA.