pH change after plasma treatment and effects of osmotic strength of background solutions.

<p>(<b>A</b>) pH of water, saline, PBS, and YPD after plasma treatment (left panel) and the effect of PBS on yeast cell viability (right panel). For pH measurements, 1 ml of each solution was exposed to plasma for the indicated time. The effect of PBS was assessed by measuring relative viability of plasma-treated cells compared to that of Ar gas-treated cells. Cells were treated with plasma for 3 min. (<b>B</b>) Viability of yeast cells in different concentrations of NaCl (left panel) and sorbitol (right panel) after plasma treatment. Yeast cells were treated with Ar gas and plasma for 1 and 3 min. (<b>C</b>) Changes in pH of NaCl (left panel) and sorbitol (right panel) solutions during plasma treatment. One ml of saline and sorbitol was exposed to plasma at the indicated concentrations for 10, 30, 60, and 180 sec. In (A) and (B), cell viability was assessed by relative ratio in colony forming units (CFU) calculated as follows: relative CFU (%) = (CFU number of plasma treated yeast/CFU number of Ar gas treated yeast)×100. All values are the average of three technical replicates.