Aspergillus niger Secretes Citrate to Increase Iron Bioavailability.

ABSTRACT: Aspergillus niger has an innate ability to secrete various organic acids, including citrate. The conditions required for A. niger citrate overproduction are well described, but the physiological reasons underlying extracellular citrate accumulation are not yet fully understood. One of the less understood culture conditions is the requirement of growth-limiting iron concentrations. While this has been attributed to iron-dependent citrate metabolizing enzymes, this straightforward relationship does not always hold true. Here, we show that an increase in citrate secretion under iron limited conditions is a physiological response consistent with a role of citrate as A. niger iron siderophore. We found that A. niger citrate secretion increases with decreasing amounts

SUBMITTER: Odoni DI 

PROVIDER: S-EPMC5539119 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature