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The mycelial biomass of basidiomycetes is a promising source of compounds and represents an alternative for industrial and biotechnological applications. Fungi use light as information and hold photoresponse mechanisms, in which sensors respond to light wavelengths and regulate various biological processes. Therefore, this study aimed to investigate the effects of blue, green, and red lights on the growth, chemical composition, and antioxidant and antimicrobial activity of Lentinus crinitus mycelial biomass. The chemical composition of the mycelial biomass was determined by chromatographic methods, antioxidant activity was analyzed by in vitro assays, and antimicrobial activity was investigated by the microdilution assay. The highest mycelial biomass yield was observed under blue-light cultivation. Many primordia arose under blue or green light, whereas the stroma was formed under red light. The presence of light altered the primary fungal metabolism, increasing the carbohydrate, tocopherol, fatty acid, and soluble sugar contents, mostly mannitol, and reducing the protein and organic acid concentrations. Cultivation under red light increased the phenol concentration. In contrast, cultivation under blue and green lights decreased phenol concentration. Benzoic and gallic acids were the main phenolic acids in the hydroalcoholic extracts, and the latter acids increased in all cultures under light, especially red light. Mycelial biomass cultivated under red light showed the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ferric reducing antioxidant power (FRAP) method showed that all light wavelengths increased the antioxidant activity of mycelial biomass, with the highest value under red light. Moreover, the β-carotene/linoleic acid co-oxidation (BCLA) assay demonstrated that the antioxidant activity was affected by light cultivation. Mycelial biomass grown under all conditions exhibited antibacterial and antifungal activities. Thus, mycelial biomass cultivation of L. crinitus under light conditions may be a promising strategy for controlling the mycelial chemical composition and biomass yield.

The influence of green light on mycelium biomass growth and extracellular enzyme activities of edible mushrooms from the Pleurotus genus, which is popularly cultivated all over the world, were investigated. The mycelium of seven strains of five species of Pleurotus (P. citrinopileatus, P. djamor, P. eryngii, P. ostreatus, and P. pulmonarius) was grown in liquid medium at 28 °C in the dark or under green light (515−530 nm). The light source was light-emitting diodes (LED) with photon flux density adjusted to 20 μmol m−2 s-1 that was kept on throughout the cultivation period. After 12 days of growth, the mycelium was recovered and used for biomass determination and the cultivation medium was used to total cellulase, endoglucanase, xylanase, and laccase activities determination. Green light reduced the mycelial biomass growth of Pleurotus spp. but increased the cellulolytic and xylanolytic activities. The cellulolytic activity of most strains increased in the presence of green light with increases ranging from 1.5 times (P. ostreatus endoglucanase) to 8 times (P. citrinopileatus total cellulase and endoglucanase). Green light reduced laccase activity for most strains with the greatest reduction for P. eryngii (2.2 times lower). The specific enzymatic activity of cellulase and endoglucanase from P. citrinopileatus, increased by 31 times and 30 times, respectively, compared to the dark. Also, the specific laccase and xylanase activities of P. pulmonarius increased 4.4 times and 6.8 times, respectively, under green light. The use of light at particular wavelengths can be a viable strategy to increase the production of enzymes for different biotechnological applications and species of Pleurotus are particularly interesting for this purpose.

Agaricus subrufescens é um cogumelo que produz lacases, oxirredutases que degradam corantes. As condições de cultivo como concentração de nitrogênio, fonte de carbono e indutores podem aumentar a produção de lacase. O objetivo deste estudo foi cultivar A. subrufescens com ureia, subprodutos agroindustriais e indutores para produzir lacase para descoloração de corantes. Agaricus subrufescens U7-1 e U7-3 foram cultivadas em meio líquido com ureia (0, 2, 4, 6 e 8 g L-1), fontes de carbono (glicose, melaço de cana-de-açúcar – MC e de soja - MS) e indutores (álcool veratrílico, etanol, guaiacol e vanilina). O extrato enzimático do cultivo foi usado na descoloração de remazol azul brilhante R (RBBR), preto reativo 5 (PR5) e verde malaquita (VM). A produção de lacase de A. subrufescens foi maior com menores concentrações de ureia e a maior atividade de lacase de U7-1 ocorreu com 2 g L-1 de ureia e U7-3 sem ureia. MC aumentou a atividade e antecipou o pico de lacase de U7-1 em cinco dias e de U7-3 em 15 dias. MS reduziu a atividade de lacase. Vanilina aumentou a atividade de lacase de U7-1 em 29% (44380 U L-1) e antecipou o pico de atividade; e vanilina e álcool veratrílico aumentaram a atividade de lacase (44770 U L-1) de U7-3, mas atrasaram o pico de atividade. Os extratos de U7-1 e U7-3 do cultivo com vanilina descoloriram o RBBR em 24 horas (65% e 75%) e VM (70%, 24 e 72 horas), mas não reduziram a cor de PR5.