I am trying to adjust the pH of a bacterial culture medium containing Peptone, 10g, Beef extract, 10 g, NaCl, 5g, pH 7.3 ± 0.1 in order to test the pH range my bacterial isolates can tolerate. I am going to use sodium acetate/acetic acid, Tris/HCl and glycine/sodium hydroxide buffers to adjust the pH of the medium to below 6, 6-9, above 9, respectively. Could anyone help me with the whole procedure. which buffering capacity for each buffer I should go with? Should I add the buffer after autoclaving or before?