A History of Iron Metabolism in the Mycobacteria - Iron Acquisition by the Genus Mycobacterium - page 7

Fig. 2.1 Frank Gerald
Augustine Winder (1928-
2007)
had been added (simply because the formulation of this medium did not include
addition of an iron or zinc salt), the cells prematurely ceased growth, failed to
form the usual pellicle and became elongated with a low level of DNA. The cells
had, in fact, been cultivated in a medium that was accidentally deficient in both
iron and zinc. In addition, the tubes being used for the cultivations had been recy-
cled a number of times thereby exhausting adventitious metal ions from the glass-
ware itself. When both iron and zinc were subsequently included in the medium,
full and normal growth of M. smegmatis was restored including restoration of
DNA synthesis.
This discovery then opened up the door to a major study of iron metabolism
in the mycobacteria by Winder and his associates that also included the author of
this review (see Fig. 2.2 ) who joined his team as a post-doctoral fellow in 1960 and
worked in the MRC of Ireland Laboratories until 1964. Winder and O'Hara [ 8 , 9 ]
then described the effects of both iron and zinc deficiencies on the composition of
M. smegmatis ; some of the key findings are summarized in Table 2.1 . However,
before these studies could begin, it was necessary to devise a simple protocol for
the removal of the trace metal ions from the medium otherwise there would be an