This study was conducted to isolate and identify potent pigment producers. From thirty-three fungal
isolates, one isolate (FPO2) which isolated from yoghurt samples was able to produce an extracellular orange
pigment. The fungal isolate was identified as M. ruber. Among the tested culture media, potato dextrose broth
(PDB) was the most suitable medium for the maximum orange pigment secretion. The supplementation PDB
with mannitol at concentration 1.5% the maximum orange pigment was produced by M. ruber. On the other
hand, the addition of any nitrogen source to the medium led to decrease in orange pigment production. Pigment
production gradually increased as the incubation period increased, reaching the maximum value (O.D460 2.856)
after 9 days. Additionally, 2% inoculum size was found to be optimum for pigment production under shaking
conditions (150 rpm) at pH 7.0 when the fungus grown at 28 °C in darkness.