The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jim A. Field - One of the best experts on this subject based on the ideXlab platform.
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oxidation of lignin in eucalyptus kraft pulp by manganese peroxidase from Bjerkandera sp strain bos55
Bioresource Technology, 2001Co-Authors: Reyes Sierraalvarez, Maria Teresa Moreira, Gumersindo Feijoo, J M Lema, Jim A. FieldAbstract:Abstract The white rot fungus Bjerkandera sp. strain BOS55 was shown in previous studies to cause high levels of kraft pulp bleaching and delignification under culture conditions in which manganese peroxidase (MnP) occurs as the dominant oxidative enzyme. In this study, the MnP of Bjerkandera was isolated and tested in vitro with eucalyptus oxygen-delignified kraft pulp (ODKP) based on measuring the reduction in kappa number as an indicator of lignin oxidation. The MnP preparation applied at 60 U/g pulp for 6 h caused a significant decrease of 11–13% in the kappa number in the ODKP under optimal conditions compared to parallel-incubated controls lacking enzyme. The effects of MnP dosage, Mn 2+ concentration, organic acid buffer selection, pH and H 2 O 2 addition were evaluated. The optimal Mn 2+ concentration range for lignin oxidation in ODKP was 100–500 μM. In the presence of low oxalate concentrations (0.3–2 mM), the Bjerkandera MnP also significantly reduced the kappa number of ODKP by 6% without any Mn. This observation is in agreement with the fact that purified Bjerkandera MnP has Mn-independent activities. Under incubation conditions with added Mn 2+ , buffers composed of metal-complexing organic acids provided two-fold better kappa number reductions compared to the inert acetic acid. The optimal H 2 O 2 dosage was found to be 0.017 μmol/min ml when added as semi-continuous pulses (every 30 min) or 0.2 μmol/min ml when generated continuously by glucose oxidase. Excess H 2 O 2 caused severe inactivation of MnP during the incubations. Factors that improved the turnover of the enzyme, such as Mn 2+ and metal-chelating acids, stabilized MnP against rapid inactivation.
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identification and synthesis of novel chlorinated p anisylpropanoid metabolites from Bjerkandera species
Journal of Natural Products, 1998Co-Authors: H J Swarts, Jim A. Field, Frank J M Verhagen, Joannes B P A WijnbergAbstract:Analysis of the EtOAc extracts from the culture medium of Bjerkandera sp. BOS55 and B. fumosa revealed the presence of two novel chlorinated metabolites. Their structures were unambiguously establi...
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role of organic acids in the manganese independent biobleaching system of Bjerkandera sp strain bos55
Applied and Environmental Microbiology, 1998Co-Authors: Maria Teresa Moreira, Reyes Sierraalvarez, Gumersindo Feijoo, Tunde Mester, Pablo Mayorga, Jim A. FieldAbstract:Bjerkandera sp. strain BOS55 is a white rot fungus that can bleach EDTA-extracted eucalyptus oxygen-delignified kraft pulp (OKP) without any requirement for manganese. Under manganese-free conditions, additions of simple physiological organic acids (e.g., glycolate, glyoxylate, oxalate, and others) at 1 to 5 mM stimulated brightness gains and pulp delignification two- to threefold compared to results for control cultures not receiving acids. The role of the organic acids in improving the manganese-independent biobleaching was shown not to be due to pH-buffering effects. Instead, the stimulation was attributed to enhanced production of manganese peroxidase (MnP) and lignin peroxidase (LiP) as well as increased physiological concentrations of veratryl alcohol and oxalate. These factors contributed to greatly improved production of superoxide anion radicals, which may have accounted for the more extensive biobleaching. Optimum biobleaching corresponded most to the production of MnP. These results suggest that MnP from Bjerkandera is purposefully produced in the absence of manganese and can possibly function independently of manganese in OKP delignification. LiP probably also contributed to OKP delignification when it was present.
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polycyclic aromatic hydrocarbon oxidation by the white rot fungus Bjerkandera sp strain bos55 in the presence of nonionic surfactants
Biotechnology and Bioengineering, 1998Co-Authors: M J J Kotterman, Henk Jan Rietberg, Annemarie Hage, Jim A. FieldAbstract:The effect of nonionic surfactants on the polycyclic aromatic hydrocarbon (PAH) oxidation rates by the extracellular ligninolytic enzyme system of the white-rot fungus Bjerkandera sp. strain BOS55 was investigated. Various surfactants increased the rate of anthracene, pyrene, and benzo[a]pyrene oxidation by two to fivefold. The stimulating effect of surfactants was found to be solely due to the increased bioavailability of PAH, indicating that the oxidation of PAH by the extracellular ligninolytic enzymes is limited by low compound bioavailability. The surfactants were shown to improve PAH dissolution rates by increasing their aqueous solubility and by decreasing the PAH precipitate particle size. The surfactant Tween 80 was mineralized by Bjerkandera sp. strain BOS55; as a result both the PAH solubilizing activity of Tween 80 and its stimulatory effect on anthracene and pyrene oxidation rates were lost within 24 h after addition to 6-day-old cultures. It was observed that the surfactant dispersed anthracene precipitates recrystallized into larger particles after Tween 80 was metabolized. However, benzo[a]pyrene precipitates remained dispersed, accounting for a prolonged enhancement of the benzo[a]pyrene oxidation rates. Because the endogenous production of H2O2 is also known to be rate limiting for PAH oxidation, the combined effect of adding surfactants and glucose oxidase was studied. The combined treatment resulted in anthracene and benzo[a]pyrene oxidation rates as high as 1450 and 450 mg L-1 d-1, respectively, by the extracellular fluid of 6-day-old fungal cultures.
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manganese is not required for biobleaching of oxygen delignified kraft pulp by the white rot fungus Bjerkandera sp strain bos55
Applied and Environmental Microbiology, 1997Co-Authors: Reyes Sierraalvarez, Maria Teresa Moreira, Gumersindo Feijoo, J M Lema, Jim A. FieldAbstract:The white rot fungus Bjerkandera sp. strain BOS55 extensively delignified and bleached oxygen-delignified eucalyptus kraft pulp handsheets. Biologically mediated brightness gains of up to 14 ISO (International Standards Organization units) were obtained, providing high final brightness values of up to 80% ISO. In nitrogen-limited cultures (2.2 mM N), manganese (Mn) greatly improved manganese-dependent peroxidase (MnP) production. However, the biobleaching was not affected by the Mn nutrient regimen, ranging from 1,000 (mu)M added Mn to below the detection limit of 0.26 (mu)M Mn in EDTA-extracted pulp medium. The lowest Mn concentration tested was at least several orders of magnitude lower than the K(infm) known for MnP. Consequently, it was concluded that Mn is not required for biobleaching in Bjerkandera sp. strain BOS55. Nonetheless, fast protein liquid chromatography profiles indicated that MnP was the predominant oxidative enzyme produced even under culture conditions in the near absence of manganese. High nitrogen (22 mM N) and exogenous veratryl alcohol (2 mM) repressed biobleaching in Mn-deficient but not in Mn-sufficient culture medium. No correlation was observed between the titers of extracellular peroxidases and the biobleaching. However, the decolorization rate of the polyaromatic dye Poly R-478 was moderately correlated to the biobleaching under a wide range of Mn and N nutrient regimens.
Bo Mattiasson - One of the best experts on this subject based on the ideXlab platform.
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decolorization of textile dyes by Bjerkandera sp bol 13 using waste biomass as carbon source
Journal of Chemical Technology & Biotechnology, 2013Co-Authors: Maria Jonstrup, Benoit Guieysse, Naresh Kumar, Marika Murto, Bo MattiassonAbstract:BACKGROUND: Phanerochaete chrysosporium, Trametes versicolor and Bjerkandera sp BOL13 were compared for decolorization of azo dyes supplied individually or as a mixture. The dye decolorization was also evaluated during continuous treatment under non-sterile conditions using a lignocellulosic growth substrate. RESULTS: Bjerkandera sp BOL13 showed the highest dye decolorization potential. This fungus was also found to support high decolorization of Remazol Red RR at an initial pH of 4-6 and when using straw as co-substrate. The fungus was evaluated for Remazol Red RR decolorization in a continuously fed packed-bed bioreactor operated under non-sterile conditions with 3 days of hydraulic retention time. When glucose was supplied as growth-substrate, decolorization efficiencies of 65-90% were maintained for 12 days in a bioreactor packed with wooden material. The decolorization efficiency was lower when glucose was not fed to the fungus or when a plastic material was used as packing. Higher manganese peroxidase and laccase activities were also recorded when the wood packing was used. Contamination caused a drop in decolorization efficiency after 17-19 days operation. CONCLUSIONS: The potential of Bjerkandera sp BOL13 for decolorization of azo dyes under non-sterile conditions using lignocellulosic growth substrates was demonstrated. Research is needed to reduce contamination under non-sterile conditions. (c) 2012 Society of Chemical Industry (Less)
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degradation of toxaphene by Bjerkandera sp strain bol13 using waste biomass as a cosubstrate
Applied Microbiology and Biotechnology, 2006Co-Authors: Enrique Terrazas, Martha Lacayo Romero, Bert Van Bavel, Bo MattiassonAbstract:The white-rot fungus Bjerkandera sp. strain BOL13 was capable of degrading toxaphene when supplied with wood chips, wheat husk or cane molasses as cosubstrates in batch culture experiments. Approximately 85% of toxaphene was removed when wheat husk was the main substrate. The production of lignin peroxidase was only stimulated when wheat husk was present in the liquid medium. Although xylanase was always detected, wheat husk supported the highest xylanase production. A negligible amount of β-glucosidase and cellulase were found in the batch culture medium. To the best of our knowledge, this is the first reported case of toxaphene degradation by white-rot fungi.
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Influence of Agitation on the Removal of Nonylphenol by the White-rot Fungi Trametes versicolor and Bjerkandera sp. BOL 13
Biotechnology Letters, 2006Co-Authors: Ana Soares, Benoit Guieysse, Bo MattiassonAbstract:Bjerkandera sp. BOL 13 removed 95% of nonylphenol (at 9.7 mg nonylphenol l^−1 day^−1) from aqueous medium after 5 days of incubation in agitated cultures. This removal rate decreased 2.5-fold in static cultures. By comparison, Trametes versicolor removed nonylphenol at 2.8 mg l^−1 day^−1 under conditions of static incubation, probably due to the action of laccase, but no growth was recorded in the agitated bottles.
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isolation and characterization of a white rot fungus Bjerkandera sp strain capable of oxidizing phenanthrene
Biotechnology Letters, 2005Co-Authors: Benoit Guieysse, Enrique Terrazassiles, Teresa Alvarez, Bo MattiassonAbstract:Strain BOL13 was selected from 18 fungal strains isolated from an oil-spill contaminated site in Oruro, Bolivia. It was identified as a basidiomycete with high homology to Bjerkandera. The fungus degraded 100 mg phenanthrene l(-1) at 0.17 mg l(-1) d(-1) at 30 degrees C at pH 7. During phenanthrene degradation, a maximum manganese peroxidase activity of 100-120 U l(-1) was measured after 10 days of incubation. The ability of Bjerkandera sp. to produce lignin-modifying enzymes and to oxidize phenanthrene under various pH and temperature conditions was confirmed.
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the ability of white rot fungi to degrade the endocrine disrupting compound nonylphenol
Applied Microbiology and Biotechnology, 2005Co-Authors: Ana Soares, Karin Jonasson, Enrique Terrazas, Benoit Guieysse, Bo MattiassonAbstract:Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor and Bjerkandera sp. BOL13 were tested for their ability to degrade the endocrine-disrupting compound nonylphenol at an initial concentration of 100 mg l−1. The highest removals were achieved with T. versicolor and Bjerkandera sp. BOL13, which were able to degrade 97 mg l−1 and 99 mg l−1 of nonylphenol in 25 days of incubation, respectively. Nonylphenol removal was associated with the production of laccase by T. versicolor, but the levels of laccase, manganese peroxidase and lignin peroxidase produced by Bjerkandera sp. BOL13 were very low. At 14°C, T. versicolor and Bjerkandera sp. BOL13 sustained the removal of 88 mg l−1 and 79 mg l−1 of nonylphenol, respectively. No pollutant removal was recorded at 4°C, although both fungi could grow at this temperature in the absence of nonylphenol. A microtoxicity assay showed that the fungi produced compounds that were toxic to Vibrio fischerii; and thus a reduction in toxicity could not be correlated with nonylphenol metabolism. T. versicolor and Bjerkandera sp. BOL13 were capable of colonizing soil artificially contaminated with 430 mg kg−1 of nonylphenol. Only 1.3±0.1% of nonylphenol remained in the soil after 5 weeks of incubation.
J M Lema - One of the best experts on this subject based on the ideXlab platform.
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degradation of selected pharmaceutical and personal care products ppcps by white rot fungi
World Journal of Microbiology & Biotechnology, 2011Co-Authors: A I Rodartemorales, Maria Teresa Moreira, Gumersindo Feijoo, J M LemaAbstract:Today, more than 3,000 pharmaceutical and personal care products (PPCPs) are used and released into the environment at low doses but they are barely degraded in wastewater treatment plants. One of the potential alternatives to effectively degrade PPCPs is based on the use of white-rot fungi (WRF) and involves the oxidative action of extracellular fungal enzymes. The aim of this work is to study the potential ability of three WRF strains, an anamorph species of Bjerkandera sp. R1, Bjerkandera adusta and Phanerochaete chrysosporium, to degrade PPCPs belonging to different therapeutic groups: anti-depressants (citalopram and fluoxetine), antibiotics (sulfamethoxazole), anti-inflammatory drugs (diclofenac, ibuprofen and naproxen), anti-epileptics (carbamazepine), tranquilizers (diazepam) and fragrances (celestolide, galaxolide and tonalide). The results reported complete degradation of all the PPCPs except for fluoxetine and diazepam, which were partially removed in percentages from 23 to 57%. In the case of fragrances, these compounds were neither detected in the fungal cultures nor in the abiotic controls, indicating the possibility of volatilization during the experiment.
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biodegradation of dibenzothiophene fluoranthene pyrene and chrysene in a soil slurry reactor by the white rot fungus Bjerkandera sp bos55
Process Biochemistry, 2007Co-Authors: Lara Valentin, Maria Teresa Moreira, Gumersindo Feijoo, Thelmo A Luchau, Carmen Lopez, J M LemaAbstract:Mass transfer phenomena can be an important constraint of the soil remediation process. With the goal of minimizing the mass transfer limitation, the degradation of four different PAHs by the white-rot fungus Bjerkandera adusta in a spiked marsh soil was evaluated in a slurry system. Key factors affecting the oxidation of PAHs with different chemical structure (two, three and four aromatic rings) were investigated. These included inoculum preparation, glucose concentration and synergic or antagonic actions between endogenous microflora and fungal culture. It was demonstrated that the fungus was able to grow and degrade the pollutants in a slurry phase stirred tank reactor. There was no significant improved effect on the degradation when the treatment was performed in presence of soil microflora. The system attained high PAH degradations, around 30 mg PAH/kg soil, after 30 days of operation under optimal conditions.
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operation of a two phase partitioning bioreactor for the oxidation of anthracene by the enzyme manganese peroxidase
Chemosphere, 2007Co-Authors: Gemma Eibes, Maria Teresa Moreira, Gumersindo Feijoo, Andrew J Daugulis, J M LemaAbstract:Abstract A study was conducted to determine the potential of a two-phase partitioning bioreactor (TPPB) for the treatment of a poorly soluble compound, anthracene, by the enzyme manganese peroxidase (MnP) from the fungus Bjerkandera sp. BOS55. Silicone oil was used as the immiscible solvent, which contained anthracene at high concentrations. The optimization of the oxidation process was conducted taking into account the factors which may directly affect the MnP catalytic cycle (the concentration of H2O2 and malonic acid) and those that affect the mass transfer of anthracene between the organic and the aqueous phase (solvent and agitation speed). The main objective was carried out in terms of improved efficiency, i.e., maximizing the anthracene oxidized per unit of enzyme used. The TPPB reached nearly complete oxidation of anthracene at a conversion rate of 1.8 mg l−1 h−1 in 56 h, which suggests the application of enzymatic TPPBs for the removal of poorly soluble compounds.
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covalent immobilisation of manganese peroxidases mnp from phanerochaete chrysosporium and Bjerkandera sp bos55
Enzyme and Microbial Technology, 2003Co-Authors: I Mielgo, Maria Teresa Moreira, C Palma, Gumersindo Feijoo, Jose M Guisan, Roberto Fernandezlafuente, J M LemaAbstract:Abstract Manganese peroxidases (MnP) from Phanerochaete chrysosporium and Bjerkandera sp. BOS55 were immobilised in glutaraldehyde–agarose gels. Four different strategies were considered concerning the activation of the support (low or high density) and the ionic strength (low or high). In terms of immobilisation rate and yield, better results were obtained when low ionic strength conditions and high density activated support (75 μEq/ml) were used. Immobilisation proceeds initially with an ionic adsorption which facilitates the further covalent attachment of the enzyme to the support. An almost complete immobilisation has been attained in a very short period (0.5–2 h). Immobilisation maintained a high percentage of MnP activity for long periods of time (activity levels of 50–60% after more than 1 year at room temperature storage). Other desirable effects such as increased thermostability at 50–60 °C for MnP from Bjerkandera and higher resistance to high H 2 O 2 concentrations for MnP for P. chrysosporium were also obtained. This latter is quite an interesting feature because it avoids the inactivation of the enzyme in the presence of an unbalanced concentration of H 2 O 2 . The improved characteristics of the immobilised MnP make its application in several fields such as the enzymatic oxidation of hardly degradable compounds more feasible.
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oxidation of lignin in eucalyptus kraft pulp by manganese peroxidase from Bjerkandera sp strain bos55
Bioresource Technology, 2001Co-Authors: Reyes Sierraalvarez, Maria Teresa Moreira, Gumersindo Feijoo, J M Lema, Jim A. FieldAbstract:Abstract The white rot fungus Bjerkandera sp. strain BOS55 was shown in previous studies to cause high levels of kraft pulp bleaching and delignification under culture conditions in which manganese peroxidase (MnP) occurs as the dominant oxidative enzyme. In this study, the MnP of Bjerkandera was isolated and tested in vitro with eucalyptus oxygen-delignified kraft pulp (ODKP) based on measuring the reduction in kappa number as an indicator of lignin oxidation. The MnP preparation applied at 60 U/g pulp for 6 h caused a significant decrease of 11–13% in the kappa number in the ODKP under optimal conditions compared to parallel-incubated controls lacking enzyme. The effects of MnP dosage, Mn 2+ concentration, organic acid buffer selection, pH and H 2 O 2 addition were evaluated. The optimal Mn 2+ concentration range for lignin oxidation in ODKP was 100–500 μM. In the presence of low oxalate concentrations (0.3–2 mM), the Bjerkandera MnP also significantly reduced the kappa number of ODKP by 6% without any Mn. This observation is in agreement with the fact that purified Bjerkandera MnP has Mn-independent activities. Under incubation conditions with added Mn 2+ , buffers composed of metal-complexing organic acids provided two-fold better kappa number reductions compared to the inert acetic acid. The optimal H 2 O 2 dosage was found to be 0.017 μmol/min ml when added as semi-continuous pulses (every 30 min) or 0.2 μmol/min ml when generated continuously by glucose oxidase. Excess H 2 O 2 caused severe inactivation of MnP during the incubations. Factors that improved the turnover of the enzyme, such as Mn 2+ and metal-chelating acids, stabilized MnP against rapid inactivation.
Maria Teresa Moreira - One of the best experts on this subject based on the ideXlab platform.
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degradation of selected pharmaceutical and personal care products ppcps by white rot fungi
World Journal of Microbiology & Biotechnology, 2011Co-Authors: A I Rodartemorales, Maria Teresa Moreira, Gumersindo Feijoo, J M LemaAbstract:Today, more than 3,000 pharmaceutical and personal care products (PPCPs) are used and released into the environment at low doses but they are barely degraded in wastewater treatment plants. One of the potential alternatives to effectively degrade PPCPs is based on the use of white-rot fungi (WRF) and involves the oxidative action of extracellular fungal enzymes. The aim of this work is to study the potential ability of three WRF strains, an anamorph species of Bjerkandera sp. R1, Bjerkandera adusta and Phanerochaete chrysosporium, to degrade PPCPs belonging to different therapeutic groups: anti-depressants (citalopram and fluoxetine), antibiotics (sulfamethoxazole), anti-inflammatory drugs (diclofenac, ibuprofen and naproxen), anti-epileptics (carbamazepine), tranquilizers (diazepam) and fragrances (celestolide, galaxolide and tonalide). The results reported complete degradation of all the PPCPs except for fluoxetine and diazepam, which were partially removed in percentages from 23 to 57%. In the case of fragrances, these compounds were neither detected in the fungal cultures nor in the abiotic controls, indicating the possibility of volatilization during the experiment.
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A new strain of Bjerkandera sp. production, purification and characterization of versatile peroxidase
World Journal of Microbiology and Biotechnology, 2010Co-Authors: Roberto Taboada-puig, Maria Teresa Moreira, Gumersindo Feijoo, Thelmo A. Lu-chau, María Jesús Martínez, Juan M. LemaAbstract:The lignin modifying enzymes (LMEs) secreted by a new white rot fungus isolated from Chile were studied in this work. This fungus has been identified as a new anamorph of Bjerkandera sp. based on the sequences of the ribosomal DNA and morphological analysis at light microscopy showing hyaline hyphae without clamp connection, cylindrical conidia and lack of sexual forms, similar to those reported in other Bjerkandera anamorphs. The characterization of the culture medium for the highest LMEs production was performed in flask cultures, with a formulation of the culture medium containing high levels of glucose and peptone. The highest Mn-oxidizing peroxidase activity (1,400 U/L) was achieved on day 6 in Erlenmeyer flasks. Four peroxidases (named R1B1, R1B2, R1B3 and R1B4), have been purified by using ion-exchange and exclusion molar chromatographies. All of them showed typical activity on Mn2+ and exhibited Mn-independent activity against 2,6-dimethoxyphenol. R1B4 showed also activity on veratryl alcohol (pH 3) indicating that this enzyme belongs to the versatile peroxidase family. The high VP production capacities of this strain, as well as the enzymatic characteristics of the LMEs suggest that it may be successfully used in the degradation of recalcitrant compounds.
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biodegradation of dibenzothiophene fluoranthene pyrene and chrysene in a soil slurry reactor by the white rot fungus Bjerkandera sp bos55
Process Biochemistry, 2007Co-Authors: Lara Valentin, Maria Teresa Moreira, Gumersindo Feijoo, Thelmo A Luchau, Carmen Lopez, J M LemaAbstract:Mass transfer phenomena can be an important constraint of the soil remediation process. With the goal of minimizing the mass transfer limitation, the degradation of four different PAHs by the white-rot fungus Bjerkandera adusta in a spiked marsh soil was evaluated in a slurry system. Key factors affecting the oxidation of PAHs with different chemical structure (two, three and four aromatic rings) were investigated. These included inoculum preparation, glucose concentration and synergic or antagonic actions between endogenous microflora and fungal culture. It was demonstrated that the fungus was able to grow and degrade the pollutants in a slurry phase stirred tank reactor. There was no significant improved effect on the degradation when the treatment was performed in presence of soil microflora. The system attained high PAH degradations, around 30 mg PAH/kg soil, after 30 days of operation under optimal conditions.
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operation of a two phase partitioning bioreactor for the oxidation of anthracene by the enzyme manganese peroxidase
Chemosphere, 2007Co-Authors: Gemma Eibes, Maria Teresa Moreira, Gumersindo Feijoo, Andrew J Daugulis, J M LemaAbstract:Abstract A study was conducted to determine the potential of a two-phase partitioning bioreactor (TPPB) for the treatment of a poorly soluble compound, anthracene, by the enzyme manganese peroxidase (MnP) from the fungus Bjerkandera sp. BOS55. Silicone oil was used as the immiscible solvent, which contained anthracene at high concentrations. The optimization of the oxidation process was conducted taking into account the factors which may directly affect the MnP catalytic cycle (the concentration of H2O2 and malonic acid) and those that affect the mass transfer of anthracene between the organic and the aqueous phase (solvent and agitation speed). The main objective was carried out in terms of improved efficiency, i.e., maximizing the anthracene oxidized per unit of enzyme used. The TPPB reached nearly complete oxidation of anthracene at a conversion rate of 1.8 mg l−1 h−1 in 56 h, which suggests the application of enzymatic TPPBs for the removal of poorly soluble compounds.
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covalent immobilisation of manganese peroxidases mnp from phanerochaete chrysosporium and Bjerkandera sp bos55
Enzyme and Microbial Technology, 2003Co-Authors: I Mielgo, Maria Teresa Moreira, C Palma, Gumersindo Feijoo, Jose M Guisan, Roberto Fernandezlafuente, J M LemaAbstract:Abstract Manganese peroxidases (MnP) from Phanerochaete chrysosporium and Bjerkandera sp. BOS55 were immobilised in glutaraldehyde–agarose gels. Four different strategies were considered concerning the activation of the support (low or high density) and the ionic strength (low or high). In terms of immobilisation rate and yield, better results were obtained when low ionic strength conditions and high density activated support (75 μEq/ml) were used. Immobilisation proceeds initially with an ionic adsorption which facilitates the further covalent attachment of the enzyme to the support. An almost complete immobilisation has been attained in a very short period (0.5–2 h). Immobilisation maintained a high percentage of MnP activity for long periods of time (activity levels of 50–60% after more than 1 year at room temperature storage). Other desirable effects such as increased thermostability at 50–60 °C for MnP from Bjerkandera and higher resistance to high H 2 O 2 concentrations for MnP for P. chrysosporium were also obtained. This latter is quite an interesting feature because it avoids the inactivation of the enzyme in the presence of an unbalanced concentration of H 2 O 2 . The improved characteristics of the immobilised MnP make its application in several fields such as the enzymatic oxidation of hardly degradable compounds more feasible.
Gumersindo Feijoo - One of the best experts on this subject based on the ideXlab platform.
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degradation of selected pharmaceutical and personal care products ppcps by white rot fungi
World Journal of Microbiology & Biotechnology, 2011Co-Authors: A I Rodartemorales, Maria Teresa Moreira, Gumersindo Feijoo, J M LemaAbstract:Today, more than 3,000 pharmaceutical and personal care products (PPCPs) are used and released into the environment at low doses but they are barely degraded in wastewater treatment plants. One of the potential alternatives to effectively degrade PPCPs is based on the use of white-rot fungi (WRF) and involves the oxidative action of extracellular fungal enzymes. The aim of this work is to study the potential ability of three WRF strains, an anamorph species of Bjerkandera sp. R1, Bjerkandera adusta and Phanerochaete chrysosporium, to degrade PPCPs belonging to different therapeutic groups: anti-depressants (citalopram and fluoxetine), antibiotics (sulfamethoxazole), anti-inflammatory drugs (diclofenac, ibuprofen and naproxen), anti-epileptics (carbamazepine), tranquilizers (diazepam) and fragrances (celestolide, galaxolide and tonalide). The results reported complete degradation of all the PPCPs except for fluoxetine and diazepam, which were partially removed in percentages from 23 to 57%. In the case of fragrances, these compounds were neither detected in the fungal cultures nor in the abiotic controls, indicating the possibility of volatilization during the experiment.
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A new strain of Bjerkandera sp. production, purification and characterization of versatile peroxidase
World Journal of Microbiology and Biotechnology, 2010Co-Authors: Roberto Taboada-puig, Maria Teresa Moreira, Gumersindo Feijoo, Thelmo A. Lu-chau, María Jesús Martínez, Juan M. LemaAbstract:The lignin modifying enzymes (LMEs) secreted by a new white rot fungus isolated from Chile were studied in this work. This fungus has been identified as a new anamorph of Bjerkandera sp. based on the sequences of the ribosomal DNA and morphological analysis at light microscopy showing hyaline hyphae without clamp connection, cylindrical conidia and lack of sexual forms, similar to those reported in other Bjerkandera anamorphs. The characterization of the culture medium for the highest LMEs production was performed in flask cultures, with a formulation of the culture medium containing high levels of glucose and peptone. The highest Mn-oxidizing peroxidase activity (1,400 U/L) was achieved on day 6 in Erlenmeyer flasks. Four peroxidases (named R1B1, R1B2, R1B3 and R1B4), have been purified by using ion-exchange and exclusion molar chromatographies. All of them showed typical activity on Mn2+ and exhibited Mn-independent activity against 2,6-dimethoxyphenol. R1B4 showed also activity on veratryl alcohol (pH 3) indicating that this enzyme belongs to the versatile peroxidase family. The high VP production capacities of this strain, as well as the enzymatic characteristics of the LMEs suggest that it may be successfully used in the degradation of recalcitrant compounds.
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biodegradation of dibenzothiophene fluoranthene pyrene and chrysene in a soil slurry reactor by the white rot fungus Bjerkandera sp bos55
Process Biochemistry, 2007Co-Authors: Lara Valentin, Maria Teresa Moreira, Gumersindo Feijoo, Thelmo A Luchau, Carmen Lopez, J M LemaAbstract:Mass transfer phenomena can be an important constraint of the soil remediation process. With the goal of minimizing the mass transfer limitation, the degradation of four different PAHs by the white-rot fungus Bjerkandera adusta in a spiked marsh soil was evaluated in a slurry system. Key factors affecting the oxidation of PAHs with different chemical structure (two, three and four aromatic rings) were investigated. These included inoculum preparation, glucose concentration and synergic or antagonic actions between endogenous microflora and fungal culture. It was demonstrated that the fungus was able to grow and degrade the pollutants in a slurry phase stirred tank reactor. There was no significant improved effect on the degradation when the treatment was performed in presence of soil microflora. The system attained high PAH degradations, around 30 mg PAH/kg soil, after 30 days of operation under optimal conditions.
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operation of a two phase partitioning bioreactor for the oxidation of anthracene by the enzyme manganese peroxidase
Chemosphere, 2007Co-Authors: Gemma Eibes, Maria Teresa Moreira, Gumersindo Feijoo, Andrew J Daugulis, J M LemaAbstract:Abstract A study was conducted to determine the potential of a two-phase partitioning bioreactor (TPPB) for the treatment of a poorly soluble compound, anthracene, by the enzyme manganese peroxidase (MnP) from the fungus Bjerkandera sp. BOS55. Silicone oil was used as the immiscible solvent, which contained anthracene at high concentrations. The optimization of the oxidation process was conducted taking into account the factors which may directly affect the MnP catalytic cycle (the concentration of H2O2 and malonic acid) and those that affect the mass transfer of anthracene between the organic and the aqueous phase (solvent and agitation speed). The main objective was carried out in terms of improved efficiency, i.e., maximizing the anthracene oxidized per unit of enzyme used. The TPPB reached nearly complete oxidation of anthracene at a conversion rate of 1.8 mg l−1 h−1 in 56 h, which suggests the application of enzymatic TPPBs for the removal of poorly soluble compounds.
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covalent immobilisation of manganese peroxidases mnp from phanerochaete chrysosporium and Bjerkandera sp bos55
Enzyme and Microbial Technology, 2003Co-Authors: I Mielgo, Maria Teresa Moreira, C Palma, Gumersindo Feijoo, Jose M Guisan, Roberto Fernandezlafuente, J M LemaAbstract:Abstract Manganese peroxidases (MnP) from Phanerochaete chrysosporium and Bjerkandera sp. BOS55 were immobilised in glutaraldehyde–agarose gels. Four different strategies were considered concerning the activation of the support (low or high density) and the ionic strength (low or high). In terms of immobilisation rate and yield, better results were obtained when low ionic strength conditions and high density activated support (75 μEq/ml) were used. Immobilisation proceeds initially with an ionic adsorption which facilitates the further covalent attachment of the enzyme to the support. An almost complete immobilisation has been attained in a very short period (0.5–2 h). Immobilisation maintained a high percentage of MnP activity for long periods of time (activity levels of 50–60% after more than 1 year at room temperature storage). Other desirable effects such as increased thermostability at 50–60 °C for MnP from Bjerkandera and higher resistance to high H 2 O 2 concentrations for MnP for P. chrysosporium were also obtained. This latter is quite an interesting feature because it avoids the inactivation of the enzyme in the presence of an unbalanced concentration of H 2 O 2 . The improved characteristics of the immobilised MnP make its application in several fields such as the enzymatic oxidation of hardly degradable compounds more feasible.