Low carbon/nitrogen ratio increases laccase production from basidiomycetes in solid substrate cultivation

Abstract

Basidiomycetes are laccase producers used for hydrolysis of lignocellulosic byproducts in fermentative processes and could be used on biofuel production or ruminant feeding. The objective of this study was to evaluate the effect of concentrations of non-protein nitrogen sources on laccase production and mycelial growth of Pleurotus ostreatus, Lentinula edodes and Agaricus blazei. The fungi were grown on soybean hulls to which urea (U), ammonium sulfate (AS) or mixture of AS:U (1:1) were added to achieve carbon/nitrogen (C/N) ratios of 5, 15, 20 or 30. The average longitudinal mycelial growth was measured and laccase activity was determined by the oxidation of 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid. Higher C/N ratios increased mycelial growth and decreased laccase production. The highest activities were obtained with a C/N ratio of 5. P. ostreatus, L. edodes and A. blazei produced more laccase when AS, AS:U and U, respectively, were added. In addition, C/N ratios lower than 30 induced laccase syntheses, inhibited mycelial growth and were a better condition for prehydrolysis of plant residues.

Effect of different compounds on the induction of laccase production by Agaricus blazei

“…Laccase production by Lentinus crinitus increases in the presence of 2.8 g/L nitrogen (Valle et al, 2014b) while that by P. ostreatus increases in the presence of 0.23 g/L nitrogen (Hou et al, 2004). The results of the present study and those of other studies (Ullrich et al, 2005;D'Agostini et al, 2011;Valle et al, 2014a) suggest that nitrogen concentrations in the range of 1.5-3.0 g/L induce maximum laccase production by A. blazei. Further, use of a protein nitrogen source such as urea promotes laccase production while use of inorganic nitrogen decreases laccase production (Piscitelli et al, 2011).…”

“…It degrades lignin and structurally similar compounds at a lower rate than white-rot fungi. A. blazei is a laccase producer (Ullrich et al, 2005;D'Agostini et al, 2011;Valle et al, 2014); however, no information is available on compounds that induce laccase production by A. blazei.…”

Fungal Pretreatment of Willow Sawdust with Abortiporus biennis for Anaerobic Digestion: Impact of an External Nitrogen Source

“…As far as the effect of AN on the decomposition of lignin is concerned, in the study of Allison et al [29] there was no significant effect for both ratios tested compared to the control, which is consistent with the findings of the present study. D'Agostini et al [30] have examined the effect of different C/N ratios (5-30, corresponding to~100 mg·N/g·C-16 mg·N/g·C) in lacasse production, during growth of three different basidiomycetes, Pleurotus ostreatus, Lentinula edodes, and Agaricus blazei on soybean hulls, by adding N in the form of AN and/or UR. It was shown that higher C/N ratios, i.e., lower N/C ratios, increased mycelial growth, but decreased laccase production.…”

Decolorization of Textile Reactive Dyes and Effluents by Biofilms of Trametes polyzona LMB-TM5 and Ceriporia sp. LMB-TM1 Isolated from the Peruvian Rainforest

“…However, the initial rate of decolorization was 1.6-fold as compared to medium 3 (6.71 mg/L h). It has been shown that decolorizing and biodegradation activities of various basidiomycetes are higher in lownutrient media due to the induction of some enzymes that contribute to the breakdown of substrates, releasing carbon and nitrogen resources (D'Agostini et al 2011;Hailei et al 2009;Iqbal et al 2011;Yamanaka et al 2008). Considering the high initial decolorizing rate of T. polyzona LMB-TM5, the indifference of Ceriporia sp.…”