title: Bioaccumulation of Cu-complex reactive dye by growing pellets of Penicillium oxalicum and its mechanism.
abstract: In this paper bioaccumulation of Cu-complex reactive dye by growing pellets of Penicillium oxalicum and its mechanism was investigated. Shaking flasks experiment showed that 99.7% of dye removal at 400 mg/l was attained after 48 h contact. Column reactor experiment showed that air lift ferment tower was a suitable reactor for both pellets formation and dye bioaccumulation. Repeated inoculation of the dye-loaded pellets accelerated dye bioaccumulation, leading to complete dye removal within 12 h. Dye initially was adsorbed on surface of cell, followed by penetration into cytoplasm. During bioaccumulation, mycelium expanded unevenly and thickened locally in diameter, generating a chain of spindles along the mycelium. In addition, the cell walls grew loose and thickened remarkably, being 4-5 folds as thick as the control one. The loose cell wall may offer both dye accumulation space and route way for dye to enter cytoplasm. There were certain unknown active matters in cytoplasm, which played an important role in dye accumulation. Desorption experiments suggested that electrostatic attraction was mainly attributed to the dye bioaccumulation.
authors.affiliation: Beijing Key Laboratory of Environmental Science and Engineering, School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing 100081, PR China. xinbaoping@bit.edu.cn
authors.forename: Baoping
authors.initials: B
authors.lastname: Xin
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Wenchai
authors.initials: W
authors.lastname: Zheng
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D002473:Cell Wall / Q000378:metabolism; D003116:Color; D004396:Coloring Agents / Q000302:isolation & purification / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D008665:Metalloporphyrins / Q000302:isolation & purification / Q000378:metabolism*; D025282:Mycelium / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D010407:Penicillium / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D056951:Photoelectron Spectroscopy; D010781:Photography; D012996:Solutions; D013347:Subcellular Fractions / Q000378:metabolism; D013499:Surface Properties
chemical_list: D004396:Coloring Agents; D008665:Metalloporphyrins; D012996:Solutions; C471069:reactive blue 21; D003300:Copper