Lentinus crinitus is a white-rot fungus that produces laccase, an enzyme used for dye decolorization. Enzyme production depends on cultivation conditions, mainly agro-industrial by-products. We aimed to produce laccase from Lentinus crinitus with agro-industrial by-products for dye decolorization. Culture medium had coffee husk (CH) or citric pulp pellet (CP) and different nitrogen sources (urea, yeast extract, ammonium sulfate and sodium nitrate) at concentrations of 0, 0.7, 1.4, 2.8, 5.6 and 11.2 g/L. Enzymatic extract was used in the decolorization of remazol brilliant blue R. CH medium promoted greater laccase production than CP in all evaluated conditions. Urea provided the greatest laccase production for CH (37280 U/L) as well as for CP (34107 U/L). In CH medium, laccase activity was suppressed when carbon-to-nitrogen ratio changed from 4.5 to 1.56, but the other nitrogen concentrations did not affect laccase activity. For CP medium, reduction in carbon-to-nitrogen ratio from 6 to 1.76 increased laccase activity in 17%. The peak of laccase activity in CH medium occurred on the 11th day (41246 U/L) and in CP medium on the 12th day (32660 U/L). The maximum decolorization within 24 h was observed with CP enzymatic extract (74%) and with CH extract (76%).

ABSTRACT. Submerged cultivation of medicinal basidiomycetes is a reproducible and efficient method of producing mycelia and metabolites. The antioxidant activity indicates its medicinal properties and is an important tool for basidiomycete screening. In this study, we analyzed the production of mycelial biomass and exopolysaccharides and the antioxidant activity of basidiomycete strains in submerged cultivation. Twenty-five strains were used for submerged cultivation in extract malt medium, and the production of mycelial biomass and exopolysaccharides was evaluated. Antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl method. Among the 25 evaluated strains, Lentinus crinitus produced the highest biomass, reaching 1190 ± 52 mg·L -1 day -1 ; Agaricus subrufescens strains had the highest exopolysaccharide production from 18.96 ± 0.15 to 20.97 ± 2.10 mg L -1 ·day -1 . Additionally, A. subrufescens showed the highest total antioxidant activity, reinforcing the therapeutic potential of this basidiomycete. No significant correlation was found between mycelial biomass or exopolysaccharide production and antioxidant activity; S.H. Umeo et al. 9908©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 9907-9914 (2015) however, the results depended on each species and the strains of the same species. We found large variations in the production of mycelial biomass and exopolysaccharides and in antioxidant activity among different species and among strains of the same species. Thus, evaluating the total antioxidant activity is an important tool for identifying strains with biotechnological potential.

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.