Abstract
Iron may play a key role in the growth of cyanobacteria, which sometimes cause to form water blooms in eutrophic water environment. To evaluate the influence of iron depletion on the growth of Anabaena circinalis, a bloom-forming cyanobacterium, ex-situ cultivation experiments using defined chemical components was conducted. It was found that (a) contrast to normal cultivation (iron concentration is at 10-6M), growth of A.circinalis was strongly suppressed by iron depletion lower than the order of 10-9M, especially assessed in terms of chlorophyll-a than cell concentration, (b) supplying iron to the growth-suppressed A.circinalis restored its growth almost to normal.
