Fig. 6.

Effect of growth medium components on 7-ethoxyresorufin-O-deethylation. a Effect of 50 mmol L⁻¹ phosphate buffer in LB medium with 500 µmol L⁻¹ 5-ALA and 4 µmol L⁻¹ heme. NaPO₄: sodium phosphate buffer, Na/KPO₄: mixed sodium/potassium phosphate buffer (37 mmol L⁻¹ Na⁺/12 mmol L⁻¹ K⁺), KPO₄: potassium phosphate buffer. b Variation of NaCl content in 50 mmol L⁻¹ potassium phosphate buffered LB supplemented with 500 µmol L⁻¹ 5-ALA and 4 µmol L⁻¹ heme. c Effect of CaCl₂ and MgCl₂ (each 1 mmol L⁻¹) in potassium phosphate buffered LB medium supplemented with 500 µmol L⁻¹ 5-ALA and 4 µmol L⁻¹ heme. d Effect of heme and 5-ALA supplementation. Protein expression was conducted in potassium phosphate buffered LB medium with either 4 µmol L⁻¹ heme, 62.5 µmol L⁻¹ heme, 500 µmol L⁻¹ 5-ALA or 500 µmol L⁻¹ 5-ALA and 4 µmol L⁻¹ heme