Figure 4.

Bacteria turbidity (optical density) studies with different citrate-based polymers (50 mg in 1 ml solution) for 28 h, in which (A) is E. coli and (B) is S. aureus. Cell suspensions without any treatment are the negative controls, while free ampicillin (2.5 μg/ml), citric acid (29 mg/ml), and commercial bacteriostatic Hydrofera Blue (50 mg in 1 ml solution) are positive controls;^#p < 0.01.