title: Biodegradation pathway and detoxification of the diazo dye Reactive Black 5 by Phanerochaete chrysosporium.
abstract: The in vivo biodegradation of the diazo dye Reactive Black 5 (RB5) by Phanerochaete chrysosporium immobilised on cubes of nylon sponge and on sunflower-seed shells (SS) in laboratory-scale bioreactors was investigated. The SS cultivation led to the best results with a decolouration percentage of 90.3% in 72 h for an initial RB5 concentration of 100 mg/L. It was found that the addition of 0.4 mM veratryl alcohol (VA) into the medium considerably increased the decolouration rate in SS cultivation. However, the addition of VA had no effect in the nylon cultivation. Thin layer chromatography (TLC) revealed that RB5 was transformed into one metabolite after 24 h. UV-vis spectroscopy and Fourier Transform Infrared (FT-IR) also confirmed the biodegradation of RB5. Toxicity of RB5 solutions before and after fungal treatment was assayed using Sinorhizobium meliloti as a sensitive soil microorganism. P. chrysosporium transformed the toxic dye RB5 into a non-toxic product.
authors.affiliation: Department of Soil Science, Faculty of Agriculture, Shahid Chamran University, Ahvaz, Iran.
authors.forename: Naeimeh
authors.initials: N
authors.lastname: Enayatizamir
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Tabandeh
authors.forename: Susana
authors.initials: S
authors.lastname: Rodríguez-Couto
authors.forename: Bagher
authors.initials: B
authors.lastname: Yakhchali
authors.forename: Hossein A
authors.initials: HA
authors.lastname: Alikhani
authors.forename: Leila
authors.initials: L
authors.lastname: Mohammadi
mesh_terms: D001673:Biodegradation, Environmental / Q000187:drug effects; D018914:Cells, Immobilized / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002855:Chromatography, Thin Layer; D003116:Color; D004396:Coloring Agents / Q000302:isolation & purification* / Q000633:toxicity*; D050296:Microbial Viability / Q000187:drug effects; D009282:Naphthalenesulfonates / Q000302:isolation & purification* / Q000633:toxicity*; D020075:Phanerochaete / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016962:Sinorhizobium meliloti / Q000166:cytology / Q000187:drug effects; D013997:Time Factors; D018675:Toxicity Tests
chemical_list: D004396:Coloring Agents; D009282:Naphthalenesulfonates; C063421:Remazol black B