Effect of colour LEDs on mycelia growth of Aspergillus ficuum and phytase production in photo-fermentations

Aspergillus ficuum grown on plates and in liquid cultures were illuminated by a white fluorescent light and four different colour LED lights (white, blue, green and red) to evaluate the regulation of LED lights on fungal growth. Biomass conversion, pellet size and phytase activity were examined. In liquid culture, luminous intensity was highly correlated with the rate of biomass conversion but did not affect pellet size. The white fluorescent light contained several different wavelengths, and therefore, its effect on A. ficuum represents the cooperative effect of these wavelengths. Strong luminance of a white fluorescent light inhibited growth of A. ficuum mycelia on plates, whereas white LED light enhanced growth. The development of mycelia was also inhibited by blue LED light and enhanced by red LED light illumination. Investigating the effect of LED lights on the growth of A. ficuum could provide evidence on the luminous intensity that is sufficient for regulating fermentation by light.