Fig. 2.

K. brevis cells remain viable after hypoosmotic stress. (A) Brevetoxin profiles for three clonal cultures (Table S1) after hypoosmotic stress. The two parent compounds, PbTx-1 (white) and PbTx-2 (gray), comprised >94% of the brevetoxin profile at day 6 after hypoosmotic stress. Derivatives (PbTx-3, -7, -9, and -cba), which would indicate cell lysis, were a small percentage of the total. (B) Comparison of growth rates for three clonal cultures acclimated to salinity treatments of 27 (black) and 35 (white) (redrawn from ref. 11) and after hypoosmotic stress produced by rapidly decreasing salinity from 35 to 27 (hatched, black and white). Error bars represent 1 SD (n = 8). Predominance of parent brevetoxin compounds and no significant decrease in growth rate indicate that cells remained intact during hypoosmotic stress.