Table VI.
The effect of pH and selected cations in the presence or absence of boric acid on the pore size of C. album cell walls
| Time/Treatment | MSL
|
|||
|---|---|---|---|---|
| Ca2+ | Mg2+ | Na+ | No Cation | |
| nm | ||||
| 2.5 h | ||||
| No boric acid | ||||
| pH 2.0 | 3.6 | 3.6 | 3.8 | 3.7 |
| pH 1.5 | 4.5 | 5.1 | 5.2 | 5.0 |
| 1 mm Boric acid | ||||
| pH 2.0 | 3.6 | 3.7 | 3.7 | 3.7 |
| pH 1.5 | 3.7 | 3.8 | 3.9 | 3.8 |
| 24 h | ||||
| No boric acid | ||||
| pH 2.0 | 3.7 | 4.7 | 4.9 | 5.0 |
| pH 1.5 | >7.0a | >7.0 | >7.0 | >7.0 |
| 1 mm Boric acid | ||||
| pH 2.0 | 3.7 | 3.8 | 3.8 | 3.8 |
| pH 1.5 | 3.9 | 5.4 | 5.6 | 5.7 |
C. album cells were grown in the presence of boric acid (100 μm) and then denatured with ethanol. The denatured cells (5 g) were rehydrated in water and then incubated in 100 mm KCl/HCl, pH 1.5 and 2.0 (20 mL), containing 50 mm CaCl2, 50 mm MgCl2, or 75 mm NaCl. At the indicated times the cells were transferred to 20 mm Na phosphate, pH 6.5, and the MSL of their walls determined.
a
MSL beyond the limit of the assay.