Effect of light on growth, intracellular and extracellular pigment production by five pigment-producing filamentous fungi in synthetic medium

The competence of the living creatures to sense and respond to light is well known. The effect of darkness and different color light quality on biomass, extracellular and intracellular pigment yield of five potent pigment producers Monascus purpureus, Isaria farinosa, Emericella nidulans, Fusarium verticillioides and Penicillium purpurogenum, with different color shades such as red, pink, reddish brown and yellow, were investigated. Incubation in total darkness increased the biomass, extracellular and intracellular pigment production in all the fungi. Extracellular red pigment produced by M. purpureus resulted maximum in darkness 36.75 ± 2.1 OD and minimum in white unscreened light 5.90 ± 1.1 OD. Similarly, intracellular red pigment produced by M. purpureus resulted maximum in darkness 18.27 ± 0.9 OD/g and minimum in yellow light 8.03 ± 0.6 OD/g of substrate. The maximum biomass production was also noticed in darkness 2.51 g/L and minimum in yellow light 0.5 g/L of dry weight. In contrast, growth of fungi in green and yellow wavelengths resulted in low biomass and pigment yield. It was found that darkness, (red 780–622 nm, blue 492–455 nm) and white light influenced pigment and biomass yield.