Biotransformation of Methylene Blue by Mixed Fungal Cultures of Gloeophyllum trabeum and Aspergillus oryzae

Abstract

This study investigated the biotransformation of methylene blue (MB) by mixed fungal cultures of Gloeophyllum trabeum and Aspergillus oryzae. Equal volumes of A. oryzae and G. trabeum cultures were applied to Erlenmeyer containing MB and incubated at 30°C for 7 days. The change in absorbance of the MB control solution and the solution after application, measured with a UV-Visible spectrophotometer, was used to calculate the decolorization. The addition of A. oryzae to G. trabeum cultures showed MB biodecolorization reaching 69.34%, greater than single cultures of G. trabeum and A. oryzae, which were 31.50% and 36.82%, respectively. Metabolite identification from MB biodecolorization by mixed culture using LC-QTOF-MS found the following metabolites:

Biodecolorization and biotransformation of methylene blue using mixed cultures of brown-rot fungus Daedalea dickinsii and filamentous fungus Aspergillus oryzae: identification of metabolites and degradation pathway

“…N -(8-(Dimethylamino)-2-pentadecyl-3 H -phenothiazin-3-ylidene)- N -methyl methanaminium (C 31 H 48 N 3 S + , m / z 494) was detected as a metabolite at retention time of 5.17 min, as shown in Table 2 . This metabolite had also been reported in the previous study by Purnomo et al 27 …”

“…Furthermore, a total of 3 metabolites were detected (Table 1) at retention times of 3.96, 6.17 detected as a metabolite at retention time of 5.17 min, as shown in Table 2. This metabolite had also been reported in the previous study by Purnomo et al 27…”

“…The ability of D. dickinsii to decolorize MB dye was related to the production of hydroxyl radicals from the Fenton reaction mechanism. Meanwhile, MB transformation occurred during decolorization with A. oryzae , and the proposed pathway had also been published by Purnomo et al 27 with m / z 494. A new pathway was also proposed in this study from mixed cultures of D. dickinsii and A. oryzae , as shown in Fig.…”

“…In fact, the biodecolorization ability of D. dickinsii and A. oryzae is still lower than the Gloeophyllum trabeum and A. oryzae mixed culture (69.34%). 27 This could be due to the different types of enzymes possessed by the two cultures. G. trabeum produces xylanase and laccase enzymes while A. oryzae produces lignolytic enzymes.…”

Adsorption and decolorization study of reactive black 5 by immobilized metal–organic framework of UiO-66 andGloeophyllum trabeumfungus

“…Subsequently, before measuring the absorbance, the solution was centrifuged at 3000 rpm for 10 min, and the supernatant was measured for its absorbance at a wavelength range of 300–800 nm. Decolorization rate was calculated at the peak wavelength exhibiting the highest absorption based on eqn (1): 23 where A o represents the absorbance of the control solution (dye) and A t is the absorbance at time t . While, adsorption capacity at time t ( Q t , mg g −1 ) is given by eqn (2): 24 where C o denotes the initial concentration (mg L −1 ), C t is the concentration at time t (mg L −1 ).…”