Enhanced Production of Fruiting Body and Bioactive Ingredients of Cordyceps militaris with LED Light Illumination Optimization

This study aimed to study the effect of different color combinations of LED light on the quantity of primordia, the formation of the fruiting body, and the yield of bioactive ingredients produced in solid culture C. militaris. The results show that appropriate color combinations and light intensities of Light-Emitting Diodes (LEDs) can significantly increase the quantity of primordia, promote the formation of fruiting bodies, and increase the yield of bioactive ingredients (cordycepin, adenosine, mannitol, and polysaccharides) in solid culture of Cordyceps militaris. LEDs have several advantages such as small size, long lifespan, fast response time, high efficiency and stability, and the ability to emit a narrow wavelength range of monochromatic light from a cold source. Our results show that both red and green-LEDs can shorten the period of primordia appearance. Red-LED increased the number of primordia and biological efficiency and red and blue LED combinations increased the biomass of the fruiting body. A light intensity of 1,000 Lux resulted in the fastest appearance of primordia, and the highest average fruiting body biomass and biological efficiency. Under different red and blue LED combinations, the highest amounts of cordycepin, adenosine, mannitol, and polysaccharide in the fruiting body of C. militaris were 15.63±0.72 (100 Lux), 23.17±1.22 (1,000 Lux), 19.84±0.84 (300 Lux), and 28.69±1.52 mg g-1 (1,000 Lux), respectively. Appropriate color combinations and intensities of LED light can significantly increase the quantity of the primordium, promote the formation of the fruiting body, and increase the yield of bioactive ingredients produced in solid culture C. militaris.