Abstract
In order to clarify the mechanism of growth of a musty-odor producing cyanobacterium Oscillatoria brevis isolated in Norway, the effects of iron forms on the growth and geosmin production of O.brevis were studied using laboratory cultures.
O.brevis grew well and produced geosmin in the EDTA-free CT medium as well as in the presence of EDTA.Thus, O.brevis showed an ability to utilize colloidal iron and even iron oxides for its growth. This suggests that O.brevis would be expected to produce a specific high affinity iron chelator (siderophore) in the chelator-free medium.
In the presence of bathophenanthroline disulfonate (BPDS), a strong Fe (II) chelating agent, O.brevis was able to grow.Furthermore, O.brevis was capable of growing in the medium containing a microbial siderophore, desferrioxamine B (DESF), instead ofEDTA.
These results show that O.brevis has an excellent ability to utilize a variety of iron forms including Fe (III) -EDTA, Fe (II) -BPDS, Fe (III) -DESF chelates, colloidal ferric hydroxide and more thermodynamically stable crystalline iron oxides (Fe2O3, Fe3O4) in comparison with musty-odor producing cyanobacteria such as Anabaena macrospora, Phormidium tenue and Oscillatoria tenuis isolated from Lake Biwa
