Influence of iron and chelator on siderophore production in Frankia strains nodulating Hippophae salicifolia D. Don.

Effect of iron and chelator on the growth and siderophore production in the ten newly Frankia strains isolated from the root nodules of Hippophae salicifolia D. Don and the two reference strains were studied. Growth of the strains was greatly affected when grown in the iron and EDTA deprived conditions. All the strains were capable of producing both the hydroxamate and catecholate type siderophore that was detected using the Csaky and Arnow assays. Production of siderophore was enhanced in the EDTA replenish condition in contrast to the iron supplemented medium suggesting that EDTA reduces the availability of other free metals and hence creates the stress condition for which the secretion of siderophore is enhanced. A decrease in siderophore production was observed with an increase in iron concentration. Strains HsIi2 and HsIi10 were found to be producing more siderophore than the other strains.