His research employs a range of molecular genetic approaches and focuses on the mechanisms used by bacteria to acquire, store and control the iron they need for growth, which is a major facet of bacterial survival and pathogenicity. He has strong interests in bacterial energy mechanisms, having discovered a novel and highly complex bacterial hydrogenease as well as identifying and characterising a new regulatory system controlling anaerobic respiration. His research has pioneered the concept of ‘iron rationing’. His more recent work has identified a novel iron regulatory mechanism (Fur-mediated anti-silencing) and a new family of iron transporters (Efe/Ftr) within bacteria.