2.4 Submerged bioprocesses for colorant production
Submerged bioprocesses were performed based on the protocol described by Celestino et al.[15] with modifications. The fungal strains were transferred to tubes containing PDA and incubated at room temperature for 72 h. The fungal spores of each strain were suspended in 5 mL of sterile distilled water and the density of the spore suspension was determined using a hemocytometer (Neubauer, Germany) under an optical microscope. This spore suspension (1x104 cell/mL) was inoculated into Erlenmeyer flasks (125 mL) containing 50 mL Czapeck broth plus yeast extract (3.0 g/L sodium nitrate, 1.0 g/L potassium phosphate, 0.5 g/L magnesium sulfate, 0.5 g/L potassium chloride, 0.01 g/L ferrous sulfate, 30.0 g/L of sucrose and 0.5 g/L yeast extract), at an initial pH of 5.0. The flasks were incubated in static conditions, in a dark place, and at room temperature (28 ÂșC) for 14 days.