Screening of mycelia and spent substrate of edible mushroom species for their dyes decolorization potential

Abstract

Eleven edible mushrooms spp. viz., Pleurotus ostreatus, P. flabellatus, P. florida,  P. fossulatus, P. sapidus, P. eryngii, P. sajor-caju, Lentinula edodes, Auricularia polytricha and Agaricus bisporus (strain U3 and S11) were screened for their mycelial growth in presence of nine structurally different dyes and their decolorization potential. Decolorization of Rhodamine B, Methyl violet 2B, Starch Azure, Reactive blue, Quinaldine Red, Chicago sky blue, Azure B, Orange II sodium salt and Methylene blue was studied on solid agar plates supplemented with dyes. Under liquid culture conditions using SMS of P. sajor-caju, highest decolorization of Methyl violet 2B (96.30%), Chicago sky blue (96.00%) and Quinaldine Red (90.17%) was recorded at pH 4.0, while that of Methylene blue (80.17%), Rhodamine B (74.44%) and Azure B (100%) at pH 7.0. For rest dyes it was at pH 10.0. Almost similar trend was with SMS of P. flabellatus. Out of 15 °C, 25 °C and 35 °C in SMS of two species 25 °C was the preferred temperature. Only exception was with Orange II sodium salt, where 35 °C was preferred temperature. Under different cultural conditions , near 100% decolorization after 72 h of incubation could be obtained for Methyl violet 2B, Azure B, Starch Azure, Quinaldine Red, Reactive blue and Chicago sky blue. Even for rest of the dyes it was in the range of 70 to 90%. The present study elucidates the potential of Pleurotus spp. and their SMS in dye decolorization and has the potential to achieve 100% decolorization potential with improved culture conditions and technological improvement.