title: Study of the degradation of dyes by MnP of Phanerochaete chrysosporium produced in a fixed-bed bioreactor.
abstract: The production of ligninolytic enzymes by the fungus Phanerochaete chrysosporium in a fixed-bed tubular bioreactor, filled with cubes of nylon sponge, operating in semi-solid-state conditions, was studied. Maximum individual manganese-dependent peroxidase (MnP) and lignin peroxidase (LiP) activities of 1293 and 225 U/l were detected. The in vitro decolourisation of two structurally different dyes (Poly R-478, crystal violet) by the extracellular liquid obtained in the above-mentioned bioreactor was monitored in order to determine its degrading capability. The concentration of some compounds (sodium malonate, manganese sulphate) from the reaction mixture was optimised in order to maximise the decolourisation levels. A percentage of Poly R-478 decolourisation of 24% after 15 min of dye incubation was achieved. On the other hand, a methodology for a long treatment of these dyes based on the continuous addition of MnP enzyme and H(2)O(2) was developed. Moreover, this enzymatic treatment was compared with a photochemical decolourisation process. The former allowed to maintain the degradation rate almost constant for a long time, resulting in a decolourisation percentage of 70% and 30% for crystal violet and Poly R-478, respectively, after 2 h of treatment. As for the latter, it was not able to degrade Poly R-478, whereas crystal violet reached a degradation of 40% in 2 h.
authors.affiliation: Department of Chemical Engineering. University of Vigo, E-36200 Vigo, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Moldes
authors.forename: S
authors.initials: S
authors.lastname: Rodríguez Couto
authors.forename: C
authors.initials: C
authors.lastname: Cameselle
authors.forename: M A
authors.initials: MA
authors.lastname: Sanromán
mesh_terms: D000880:Anthraquinones / Q000378:metabolism*; D000891:Anti-Infective Agents, Local / Q000378:metabolism*; D019149:Bioreactors; D004396:Coloring Agents / Q000378:metabolism*; D005840:Gentian Violet / Q000378:metabolism*; D020075:Phanerochaete / Q000502:physiology*; D010777:Photochemistry; D011108:Polymers / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D000880:Anthraquinones; D000891:Anti-Infective Agents, Local; D004396:Coloring Agents; D011108:Polymers; D014874:Water Pollutants, Chemical; C017971:poly R-478; D005840:Gentian Violet