Biodegradation of phenol by Pseudomonas putida immobilized on activated pumice particles

WOS: 000227569000042Pseudomonas putida was acclimized to phenol by increase in concentration and the degradation rate was calculated as approximately 0.042 g l(-1) h(-1) in batch shake flask cultures. Phenol degradation by P. putida immobilized on several silica based support materials was investigated. Pumice was chosen as a support material and then partially characterized physically and chemically. The cell adsorption ratio was 91% with Zr-activated pumice. The biocatalyst completely degraded 1.0 g l(-1) phenol in the batch shaking system in 22 h and it was also used in recycled and continuous mode packed bed bioreactors for phenol degradation. The performance of the bioreactor was tested by running five times and it was observed that the degradation rates did not change for the first four runs. The biodegradation rate becomes high and concentration-independent in recycled packed bed bioreactors for phenol degradation. The reactor performance at high phenol concentration for the reactor tolerance was 1.25 g phenol l(-1). Continuous degradation of phenol in a packed bed bioreactor was also studied. The phenol concentrations in the feed tank was increased with a constant dilution rate (2.27 h(-1)) from 0.065 to 0.820 g l(-1). The maximum phenol degradation level of 99% was reached at a phenol loading rate of 0.001-0.002 g l(-1). The biocatalyst could be stored at 4 degrees C for 6 months without significant decrease in activity. (c) 2004 Elsevier Ltd. All rights reserved

immobilized cells in a recycled packed bed reactor

Fluorene degradation using immobilized Pleurotus ostreatus on various supports including polystyrene foam, Amberlite XAD-7, Amberlite XAD-2000, pumice particles and sand has been reported. These supports have yielded positive results with regard to performing metabolic functions, but the drawback of synthetic resins is that they are not eco-friendly. If natural supports could be used for cell immobilization for the degradation of fluorene, they would be both eco-friendly and perform metabolic functions. Therefore. This study attempts to design an immobilized P. ostreatus using pumice as a support specifically for the application of fluorene biodegradation in batch shaking systems. Laccase and MnP enzyme activities were monitored in these systems. The maximum fluorene degradation level was 89.16%. Batch degradation of fluorene in a packed bed reactor was also studied. The maximum fluorene degradation level was found to be 82.46%. Additionally, two different, synthetically concocted wastewater samples containing fluorene were studied in a recycled packed bed reactor in repeated mode. At the end of biodegradation process, the metabolites of the fluorene biodegradation produced by immobilized P. ostreatus were analyzed via GC-MS and FT-IR. It was concluded that the biotransformation of fluorene by immobilized P. ostreatus was achieved. (c) 2011 Elsevier Ltd. All rights reserved

immobilized cells in a recycled packed bed reactor

Fluorene degradation using immobilized Pleurotus ostreatus on various supports including polystyrene foam, Amberlite XAD-7, Amberlite XAD-2000, pumice particles and sand has been reported. These supports have yielded positive results with regard to performing metabolic functions, but the drawback of synthetic resins is that they are not eco-friendly. If natural supports could be used for cell immobilization for the degradation of fluorene, they would be both eco-friendly and perform metabolic functions. Therefore. This study attempts to design an immobilized P. ostreatus using pumice as a support specifically for the application of fluorene biodegradation in batch shaking systems. Laccase and MnP enzyme activities were monitored in these systems. The maximum fluorene degradation level was 89.16%. Batch degradation of fluorene in a packed bed reactor was also studied. The maximum fluorene degradation level was found to be 82.46%. Additionally, two different, synthetically concocted wastewater samples containing fluorene were studied in a recycled packed bed reactor in repeated mode. At the end of biodegradation process, the metabolites of the fluorene biodegradation produced by immobilized P. ostreatus were analyzed via GC-MS and FT-IR. It was concluded that the biotransformation of fluorene by immobilized P. ostreatus was achieved. (c) 2011 Elsevier Ltd. All rights reserved

cells

Fluorene is one of the most common polycyclic aromatic hydrocarbons found in the environment and it is listed as a priority pollutant by EPA. In this present work, the biodegradation of fluorene (a polycyclic aromatic hydrocarbon) by Trametes versicolor (T. versicolor), Trametes trogii (T. trogii), Ganoderma carnasum (G. carnasum) and Pleurotus ostreatus (P. ostreatus) was investigated. While T. versicolor, T. trogii and G. carnasum degraded fluorene by 30%, P. ostreatus metabolized approximately 85% of a solution containing 30.0 mg L-1 of fluorene within six weeks. Additionally, this strain was able to completely degrade the fluorene in a 50.0-mg L-1 solution and was selected for further study. P. ostreatus were subject to varying fluorene concentrations and showed that cell growth toxicity increased with increasing fluorene levels in growth media. Furthermore, P. ostreatus reduced the fluorene in a 5.0-mg L-1 solution by 92.9%. Laccase and manganese peroxidase enzyme activity were also monitored to determine possible roles in fluorene degradation. Gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR) analyses were also employed to identify metabolites. These results indicate that no remarkable metabolite was detected at the end of degradation process. (c) 2010 Elsevier Ltd. All rights reserved

A novel carrier for Phanerochaete chrysosporium immobilization

WOS: 000225928600008PubMed ID: 15974183Phanerochaete chrysosporium BKMF-1767 cells were immobilized on different carriers. The optimum carrier according to adsorbed P. chrysosporium cells number (86.38%) was determined to be polystyrene foam, a novel carrier. The conditions for the immobilization of cells on polystyrene foam were optimized and determined as 50 rpm, 37degreesC, and 2 h. The results show that the adsorption of P. chrysosporium on polystyrene foam follows the Langmuir adsorption isotherm. High manganese peroxidase activity (421 U/L) and dry mass (4.7 g/L) were recovered from the batch mode polystyrene foam solid state fermentation system

Treating denim fabrics with immobilized commercial cellulases

Immobilization of a commercial cellulase (C) onto chemically modified pumice (P) particles has been studied. ZrOCl2 activated pumice was used as a carrier for the cellulase immobilization and some operational properties of this carrier were determined. Denim washing performance of immobilized cellulase (MP) was also investigated comparing with free enzymes (FE) and traditional denim washing procedure. Immobilized acid cellulases can efficiently abrade indigo dyed denim fabrics. (C) 2004 Elsevier Ltd. All rights reserved

Laccase: production by Trametes versicolor and application to denim washing

WOS: 000227569000026Laccase activity was monitored in synthetic media supplemented with various phenolics. Phenol was the most effective inducer. The white rot basidiomycete Trametes versicolor grown in non-induced and phenol induced conditions, was tested for production of laccase (TvLac), lignin peroxidase (LiP), manganese peroxidase (MnP), arylalcohol oxidase (AAO) and polyphenol oxidase (PPO). Although no PPO, LiP and AAO were observed in the culture filtrates, TvLac and MnP activities were detected at the fourth and fifth day of incubation, respectively. In phenol induced cultures, the maximum enzyme activity was enhanced about 20-fold with regard to control cultures. Laccase production at optimum phenol concentration was investigated by monitoring enzyme activity, protein content, glucose consumption and biomass and it was determined that laccase production is non-growth associated. The optimum pH of the enzyme was 4.5. Kinetic constants of TvLac was determined as K. value 0.6 1mM and a V-max of 8264 U/L (R-2 = 0.99). Laccase, isolated from T.versicolor, was also used for denim washing without a mediator. TvLac was more effective than commercial laccase with a mediator. (c) 2004 Elsevier Ltd. All rights reserved

Biodecolourization of Direct Blue 15 by immobilized Phanerochaete chrysosporium

WOS: 000227569000057In vitro and in vivo biodecolourization of structurally different nine direct azo dyes by Phanerochaete chrysosporium immobilized on ZrOCI, -activated pumice was studied in stationary cultures. No lignin peroxidase activity was detected in the extracellular medium of R chrysosporium. In order to support dye degradation, ligninolytic culture filtrate from fungus, containing mainly manganese peroxidase, was treated with dye. Direct Blue 15 (DB15, 120 mg/l) was determined as the best decolourized dye and its decolourization by immobilized P. chrysosporium was studied in a small-scale packed-bed reactor (PBR). The colour removal efficiency in repeated batches was found as 95-100%. Kinetic analysis of enzymatic decolourization of DB15 indicate that the process is time dependent and follows first-order kinetics with respect to initial concentrations of dye. The rates of colour removal (k values) decrease to a significant extent with increasing initial concentrations of dye. In this decolourization process, it was observed that MnP played an important role while there was no obvious role for UP and adsorption was determined as a minor mechanism in decolourizing DB15. (c) 2004 Elsevier Ltd. All rights reserved