The acquisition of essential trace metals is a fundamental requirement for metalloprotein function but is often a challenge for microbes: Too low a concentration results in suboptimal uptake but too high a concentration of any metal (including essential metals) is toxic. Microbes cope by releasing strong metal binding secondary metabolites that control metal uptake. Despite their importance as "gatekeeper" metabolites, our knowledge of biogenic metal chelators is limited. At Princeton, I work in collaboration with analytical chemists to understand the diversity of strategies bacteria use to obtain essential trace metals.
Baars O., Morel F.MM, Zhang X.. 2018. The purple non-sulfur bacterium Rhodopseudomonas palustris produces novel petrobactin related siderophores under aerobic and anaerobic conditions. Environmental Microbiology. 5:1667-1676. doi: 10.1111/1462-2920.14078
Baars O., Zhang X., Gibson M.I, Stone A.T, Morel F.MM, Seyedsayamdost M.R. 2018. Crochelins: Siderophores with an Unprecedented Iron-Chelating Moiety from the Nitrogen-Fixing Bacterium Azotobacter chroococcum. Angewandte Chemie. 57(2):536-541. doi: 10.1002/anie.201709720
Baars O, Zhang X, Gibson MI, Stone AT, Morel FMM, Seyedsayamdost MR. 2017. Crochelins, siderophores with a novel iron-chelating moiety from the nitrogen-fixing bacterium Azotobacter chroococcum. Angewandte Chemie. 57:536-541. doi: 10.1001/anie.201709720/epdf
Baars O., Zhang X., Morel F.MM, Seyedsayamdost M.R. 2016. The Siderophore Metabolome of Azotobacter vinelandii. Applied and Environmental Microbiology. 82(1):27-39. doi: 10.1128/AEM.03160-15