Decolorization and degradation of Congo red by a newly isolated white rot fungus, Ceriporia lacerata, from decayed mulberry branches

Abstract

A newly isolated white-rot fungus named ZJSY, was isolated from the decayed mulberry branches using the method of decolorization zone. According to the morphological characteristics and sequence analysis of 18S rDNA, the strain was identified as Ceriporia lacerata. ZJSY was capable of decolorizing Congo red under the statically air-opened condition. Initial dye concentration, biomass dosage, temperature and initial pH of dye solution affected the decolorization rate. The optimum temperature and initial pH value for decolorization were 30 °C and 8, respectively. The decolorization rate could reach above 90% at 48 h when 3 g mycelia were added into 20 mL of Congo red solution with the concentration 0.1 mg mL−1. The decolorization was caused by both absorption of mycelia and degradation of enzymes mainly including manganese peroxidase (MnP) which could bio-transformed Congo red into naphthylamine and benzidine at 48 h. Toxicity test suggested the products at 48 h were more toxic than original dye. Overall findings showed that Ceriporia lacerate had good decolorization ability to Congo red and had well potential application prospects in the field of dye wastewater treatment.