Comparative proteomic analysis of Pleurotus ostreatus mycelia grown in submerged fermentation under different light wavelength

Light is a key environmental factor in the growth, development, and metabolism of the edιble mushroom Pleurotus ostreatus. In this study, the effect of white, blue, green, yellow, red light, and darkness on the global protein expression profile of P. ostreatus LGAM 1123 grown in submerged cultivation was investigated. No inhibition of the growth of the fungus, in all the light conditions tested, compared to the dark, was observed. However, the mycelial protein content was reduced by 10% in blue and white light. From the proteomic analysis, a different proteome was expressed for each light wavelength, with red and blue light presenting the most distinctive proteome profiles. Blue light induces pathways such as the citrate cycle (TCA cycle), glycolysis/gluconeogenesis and biosynthesis of amino acids, while red light induces mRNA-related pathways. GC-MS analysis of biomass revealed differences in the produced amino acids, sugars, and lipids. The distinct regulation of proteins and bioactive compounds under different light wavelengths growth indicate that using a specific light wavelength, the metabolism of P. ostreatus could turn into particular biochemical pathways. These strategies could be useful for the food industry because specific nutrients could be increased in the fermentation of edible fungi without the need for genetic engineering of the strain.