Investigation of Mn peroxidase production and dye decolorization ability of newly isolated Bjerkandera adusta

In this study, peroxidase production and dye decolorization activity of the newly isolated white rot fungus Bjerkandera adusta were investigated under various conditions. Firstly, its peroxidase activity was tested on SDA media containing MnSO4 as manganese source. Fungal growth caused brown color. It was stated that the formation of brown color was due to the manganese peroxidase activity of the fungi. Moreover, horseradish peroxidase like activity was determined during liquid and solid phase fermentation conditions. It was shown that crude culture filtrate of this fungus possess peroxidase enzyme with Reactive Blue 171 dye decolorization activity. This crude enzyme source showed high peroxidase activity at 4-50 C and pH 2.6-4.5. The dye decolorization activity of this fungus against various dyes such as Reactive Blue 171 (RB 171), Indigo Carmine, Remazol Brilliant Blue R, Astrazon Blue and Astrazon Black was also investigated. Bjerkandera adusta could decolorize all of the dyes under batch conditions. Decolorization of various dyes by fungal pellets was also studied under non-sterile conditions and it was shown that fungal pellets could decolorize all the dyes used. The longevity of decolorization activity of the pellets was also investigated under repeated-batch conditions. The pellets were stable at least for three times with residence time of 30 min for RB 171 and 24 h for the other dyes, during repeated-batch experiments. Moreover, these pellets had high dye decolorization activity under repeated-batch conditions. The pellets showed and maintained the dye decolorization activity under non-sterile conditions. Because it is unpractical to use the sterilization and sterile medium, decolorization under non-sterile conditions has great value.