Fig 4.
Aggregation efficiency is pH dependent, with optimal aggregation occurring at pH 9 and above. Aggregation at pH 9 is significantly higher than that at pH 8 (P = 5.9E−8). Aggregation above pH 9 is not significantly increased (P > 0.05). There was no significant change in aggregation below pH 8 (P > 0.05). Bars and error bars represent the means and standard errors, respectively, of eight independent aggregation reactions. A value of 100% is aggregation of all algal cells.