TITLE:
Impact of Iron Availability on Bacillus amyloliquefaciens Growth
AUTHORS:
D. Clark, C. Youngblood, M. Taplin, E. Brown, B. S. Williams, C. Phillips, B. Garner
KEYWORDS:
Bacillus, Catechol, Hemolysis, Iron
JOURNAL NAME:
Advances in Microbiology,
Vol.4 No.13,
October
21,
2014
ABSTRACT: Bacillus amyloliquefaciens is a biocontrol agent whose genome has been sequenced. Within the genome of B. amyloliquefaciens are genes
associated with iron chelation, but these genes are not found within all
sequenced strains. The impact of iron availability on the B. amyloliquefaciens physiology was examined in this study. B. amyloliquefaciens ATCC 23843 was
cultured under ironreplete and iron-deplete conditions for 48 hours, at 37°C. Final growth yields were dependent on iron
concentration. Cultures grown in the absence of detectable iron were restricted
in growth, but reached their highest yields at 48 hours. Iron restriction was
confirmed by the presence of iron chelators in the filtrates. In contrast, B. amyloliquefaciens ATCC 23843 cultures
grown with ferric ammonium citrate as the iron source research reached the
highest yields at 24 hours. Iron chelator production was not detected in the
ferric ammonium samples. A significant decrease in turbidity was observed for
these cultures, which coincided with elevated spore production in B. amyloliquefaciens ATCC 23843. A
decrease in turbidity was also observed on blood agar, where hemolysis was
readily evident. We propose that iron impacts numerous physiological responses
and further studies will elucidate the complex regulatory mechanisms governed
by iron availability.