LIGNINOLYTIC ACTIVITY PATTERNS OFPleurotus ostreatusOBTAINED BY SUBMERGED FERMENTATION IN PRESENCE OF 2,6-DIMETHOXYPHENOL AND REMAZOL BRILLIANT BLUE R DYE

Abstract

The degradation of 2,6-dimethoxyphenol (DMP) and decolorization of Remazol brilliant blue R dye (RBB), added to culture media of Pleurotus ostreatus developed in submerged fermentation, and the laccase, manganese peroxidase and veratryl alcohol oxidase activities produced in these systems were evaluated. Both compounds were removed from the culture medium mainly by enzymatic action. These compounds decreased the specific growth rate and the effect on the maximal biomass values was not important. The enzymatic activities were increased by DMP and/or RBB; however, the DMP showed a higher inducer effect on all enzymes than RBB. On the other hand, the RBB showed a larger inducer effect on manganese peroxidase activity than on the laccases and veratryl alcohol oxidase activities. These results show that DMP was a better inducer of ligninolytic enzymes than dye, and the process of dye decolorization and degradation of DMP requires the action of all enzymes of the ligninolytic complex.

Heterologous Expression of Laccase (LACP83) of Pleurotus ostreatus

“…In addition, the value of laccase activity of this work was 2 times higher than that reported by Park et al (2015), where the Lacc6 gene from P. ostreatus was expressed in P. pastoris, obtaining values of 1560 U/L. The wild strain of P. ostreatus produced 3190 U/L at 144 h of culture (Grandes-Blanco et al 2013), while in this work, the recombinant strain of E. coli produced a similar activity in 19 h. …”

Molecular docking of oxidases from Pleurotus ostreatus and the activity of those produced by ARS 3526 strain grown in both, submerged and solid-state fermentations

“…For all enzymes, activity was reported in international units (U, amount of enzyme that is required to oxide one µmol of substrate per minute in the reaction mixture), but Lac activity was also informed in arbitrary units (AU, amount of enzyme that is required to increase the absorbance in one unit in the reaction mixture). Lac activity was measured in the reaction mixture that contained 950 µL substrate (2 mM DMP in 0.1 M phosphate buffer, pH 6.5) and 50 µL of EE, after one min of incubation the absorbance was read at 468 nm (ε= 35645 cm −1 M −1 ) (Grandes- Blanco et al, 2013). The MnP activity was determined in the assay mixture, containing 850 µL of substrate (0.5 mM manganous sulphate in 50 mM sodium malonate buffer, pH 4.5), 100 µL of EE and 50 µL of 0.05 mM H 2 O 2 , incubated at 30ºC for one minute, after that the absorbance at 270 nm (ε=11590 cm −1 M −1 ) was read (Giardina et al, 2000).…”

Ligninolytic Enzyme Production and Decolorization Capacity of Synthetic Dyes by Saprotrophic White Rot, Brown Rot, and Litter Decomposing Basidiomycetes

“…Much information on the decolorization of synthetic dyes by ligninolytic fungi has been obtained with Phanerochaete chrysosporium [11,37,39,56], Pleurotus ostreatus [16,49,54,57,65,68,77], Trametes versicolor [25,42,50,85], or Bjerkandera adusta [76,95,96]. Our screening showed 12 strains with the best decolorization properties.…”