Iron Dependency of and Transport by Cyanobacteria
Kerstin Nicolaisen and Enrico Schleiff
from: Iron Uptake and Homeostasis in Microorganisms (Edited by: Pierre Cornelis and Simon C. Andrews). Caister Academic Press, U.K. (2010)
Abstract
Cyanobacteria are dependent on but can also be compromised by metals such as iron. On the one hand the demand for iron for photosystem functionality represents a challenge for the iron uptake machinery in iron limiting environments. On the other hand intoxication by iron causes a severe problem for growth and reproduction. To overcome this dilemma cyanobacteria have developed a regulatory network controlling iron uptake. They produce siderophores, which are distinct from that of other bacteria. Furthermore, the iron metabolism is linked to the nitrogen metabolism as documented for example in Anabaena sp. PCC 7120. In this chapter we focus on three aspects of this regulatory system. We describe the physiological consequence of iron starvation or iron intoxication in cyanobacteria. Especially molecular, morphological and physiological changes will be discussed. In the second part we elucidate the regulatory network sensing the iron status within the cell with focus on the Fur mediated transcriptional network and its cross talk to other regulatory systems. In the final section we focus on the molecular components involved in uptake of iron by cyanobacteria read more ...
