Collapsing Aged Culture of the Cyanobacterium Synechococcus elongatus Produces Compound(s) Toxic to Photosynthetic Organisms
Figure 5
Cells respond to CM in a density dependent manner.
(A) Exponentially growing cells of S. elongatus were inoculated into conditioned medium (CM) at different initial cell densities, as indicated by the optical density at 750 nm (OD750). (B) Chloramphenicol, an inhibitor of protein synthesis, impaired the ability of high density cultures to cope with the deleterious effect of CM. (C) Cells coped better with CM when it was not supplemented with nutrients. (D and E) Inactivation of the nblR gene, encoding a response regulator essential for nutrient starvation responses, results in extreme sensitivity to CM. Data shown in B-D represent cells exposed to CM at OD750 = 0.04. Note the different y axis scale in (C) versus (B) and (D).
