Figure 4.

Protective effect of various amino acids against the toxic effect of BMAA. (A) Competition experiments with BMAA and amino acids in BG11. Anabaena was cultured in liquid medium with shaking in plastic vials, without BMAA (control) or with 25 μM BMAA. The concentration of each amino acid is 250 μM. After five days of incubation, the cultures were imaged. (B) Competition experiments with BMAA and amino acids in BG11₀ deprived of combined nitrogen. The experiments were carried out similarly to (A) except the concentration of each amino acid is 100 μM. (C,D) Similar competition experiments as in A and B, except that the ration between BMAA and each amino acid varied from 0:0, to 1:0, 1:1, 1:2, 1:5, and 1:10. All cultures were started with a similar OD at 0.07 in BG11 (C) or BG11₀ (D). After seven days of incubation, the cultures were imaged.