The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction wi... more The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction with excellent antioxidant properties.
The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction wi... more The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction with excellent antioxidant properties.
Bioreactor systems have been developed as alternatives to standard culture flasks due to their ho... more Bioreactor systems have been developed as alternatives to standard culture flasks due to their homogeneous nature, easiness of monitoring and increased cell production. Here we investigated the in vitro expansion of bone marrow (BM) mesenchymal stem cells (MSC) in spinner flasks, using gelatin microcarriers (Cultispher S) to support cell adhesion and proliferation. MSC expansion was performed using a low-serum containing medium (2% of fetal bovine serum, FBS).A strategy was defined for the maximization of cell expansion: microcarriers were pre-coated with FBS in order to increase cell seeding efficiency and an adequate feeding regime was established (25% medium exchange everyday). The maximum cell density, 4.2 × 105 cells/mL, was obtained at day 8, corresponding to a fold increase in total cell number of 8.4 ± 0.8. Expanded MSC retained their differentiation potential into adipogenic and osteogenic lineages, as well as their clonogenic ability. Harvested cells expressed >90% of CD73, CD90 and CD105 markers.These results demonstrated that a microcarrier-based stirred culture system is adequate for human MSC expansion, using a low-serum containing medium, allowing the generation of significant cell numbers for potential applications in regenerative medicine.
ABSTRACT Although the removal of steroid estrogens by enzymatic treatment with free fungal enzyme... more ABSTRACT Although the removal of steroid estrogens by enzymatic treatment with free fungal enzymes has been already demonstrated in previous batch experiments, the main limitations associated to this system are the low productivity and degradation yield, typical of batch operations, as well as the unfeasibility of reusing the enzyme. With the aim of overcoming these drawbacks, an enzymatic membrane reactor (EMR) was designed for the continuous removal of estrone (E1) and estradiol (E2) by a commercial laccase from Myceliophthora thermophila. The use of an ultrafiltration membrane allowed the separation of the enzyme according to its high molecular weight while the degradation products could pass through it. Not only the continuous operation was proved, but also different operational parameters were assessed for their relevance on the efficiency of the process. Accordingly, the effects of laccase activity (500-1,000 U/L), hydraulic residence time (1-4 h) and oxygen frequency supply (2-8 pulses of oxygen each HRT) were investigated. Removal efficiencies between 64-100 % and degradation rates of 0.96-2.92 mg/(L.h) were attained. Furthermore, the residual estrogenic activity of the effluent was largely reduced up to 97 %. The present work proves the feasibility of using a laccase-mediated reactor for the continuous removal of estrogenic compounds.
ABSTRACT A Two Phase Partitioning Bioreactor (TPPB) was proposed to carry out the degradation of ... more ABSTRACT A Two Phase Partitioning Bioreactor (TPPB) was proposed to carry out the degradation of the poorly soluble compound anthracene by laccase from Trametes versicolor. The organic phase consisted of silicone oil saturated with anthracene. The surfactant (Triton X-100) was added to the aqueous phase at concentration above the critical micelle concentration (CMC) to enhance anthracene solubility. The feasibility of reusing the aqueous phase, containing the laccase-mediator system was tested in three consecutive cycles of 24 h with an initial laccase activity of 1200 U/L and 1 mM of the mediator 1-hydroxybenzotriazole (HBT). In the first cycle, total degradation of anthracene took place at a high conversion rate: 16 mu mol/L(R)h. The degree of removal achieved in two subsequent cycles with no extra addition of laccase or HBT were 68 % and 40 % for a laccase activity of 150 and 90 U/L in each cycle respectively. These results proved the potential of a TPPB including a surfactant for the removal of poorly soluble compounds by the enzyme laccase and the possibility of exhausting the oxidative potential of the aqueous phase in consecutive cycles to minimize consumption of both laccase and the mediator.
Transformation Products of Emerging Contaminants in the Environment, 2014
ABSTRACT Natural and synthetic endocrine disrupting chemicals (EDCs) are released into the enviro... more ABSTRACT Natural and synthetic endocrine disrupting chemicals (EDCs) are released into the environment, mainly through sewage treatment systems, before reaching the receiving bodies. It is crucial to maintain ongoing efforts to develop, validate and/or update the current approaches for the effective removal of EDCs. White-rot fungi (WRF) secrete mediators of high molecular weight, increasing the range of compounds potentially biodegradable. The enzymatic membrane reactor (EMR) configuration detailed in this chapter consists of a continuous stirred tank reactor coupled to an ultrafiltration polyethersulfone membrane with a nominal molecular weight cut-off of 10kDa, which allows the recovery and recycling of the enzyme to the reaction vessel. The most common transformation products (TPs) from advanced oxidation processes (AOPs) are obtained by the breakdown of the EDC structure, yielding molecules with lower molecular weight than that of the parent compound and reduced estrogenic activity.
The goal of this study is the development of a system based on the use of the ligninolytic enzyme... more The goal of this study is the development of a system based on the use of the ligninolytic enzyme Manganese Peroxidase (MnP) for the degradation of polycyclic aromatic hydrocarbons (PAHs), of which anthracene was selected as an example. A main problem of these compounds is their poor solubility in aqueous media. Therefore, the addition of different water miscible organic solvents
In this chapter, the engineering aspects of processes catalyzed by peroxidases will be presented.... more In this chapter, the engineering aspects of processes catalyzed by peroxidases will be presented. In particular, a discussion of the existing technologies that utilize peroxidases for different purposes, such as the removal of recalcitrant compounds or the synthesis of polymers, is analyzed. In the first section, the essential variables controlling the process will be investigated, not only those that are
The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction wi... more The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction with excellent antioxidant properties.
The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction wi... more The oligomerization of esculin by laccase in aqueous medium resulted in a precipitate fraction with excellent antioxidant properties.
Bioreactor systems have been developed as alternatives to standard culture flasks due to their ho... more Bioreactor systems have been developed as alternatives to standard culture flasks due to their homogeneous nature, easiness of monitoring and increased cell production. Here we investigated the in vitro expansion of bone marrow (BM) mesenchymal stem cells (MSC) in spinner flasks, using gelatin microcarriers (Cultispher S) to support cell adhesion and proliferation. MSC expansion was performed using a low-serum containing medium (2% of fetal bovine serum, FBS).A strategy was defined for the maximization of cell expansion: microcarriers were pre-coated with FBS in order to increase cell seeding efficiency and an adequate feeding regime was established (25% medium exchange everyday). The maximum cell density, 4.2 × 105 cells/mL, was obtained at day 8, corresponding to a fold increase in total cell number of 8.4 ± 0.8. Expanded MSC retained their differentiation potential into adipogenic and osteogenic lineages, as well as their clonogenic ability. Harvested cells expressed >90% of CD73, CD90 and CD105 markers.These results demonstrated that a microcarrier-based stirred culture system is adequate for human MSC expansion, using a low-serum containing medium, allowing the generation of significant cell numbers for potential applications in regenerative medicine.
ABSTRACT Although the removal of steroid estrogens by enzymatic treatment with free fungal enzyme... more ABSTRACT Although the removal of steroid estrogens by enzymatic treatment with free fungal enzymes has been already demonstrated in previous batch experiments, the main limitations associated to this system are the low productivity and degradation yield, typical of batch operations, as well as the unfeasibility of reusing the enzyme. With the aim of overcoming these drawbacks, an enzymatic membrane reactor (EMR) was designed for the continuous removal of estrone (E1) and estradiol (E2) by a commercial laccase from Myceliophthora thermophila. The use of an ultrafiltration membrane allowed the separation of the enzyme according to its high molecular weight while the degradation products could pass through it. Not only the continuous operation was proved, but also different operational parameters were assessed for their relevance on the efficiency of the process. Accordingly, the effects of laccase activity (500-1,000 U/L), hydraulic residence time (1-4 h) and oxygen frequency supply (2-8 pulses of oxygen each HRT) were investigated. Removal efficiencies between 64-100 % and degradation rates of 0.96-2.92 mg/(L.h) were attained. Furthermore, the residual estrogenic activity of the effluent was largely reduced up to 97 %. The present work proves the feasibility of using a laccase-mediated reactor for the continuous removal of estrogenic compounds.
ABSTRACT A Two Phase Partitioning Bioreactor (TPPB) was proposed to carry out the degradation of ... more ABSTRACT A Two Phase Partitioning Bioreactor (TPPB) was proposed to carry out the degradation of the poorly soluble compound anthracene by laccase from Trametes versicolor. The organic phase consisted of silicone oil saturated with anthracene. The surfactant (Triton X-100) was added to the aqueous phase at concentration above the critical micelle concentration (CMC) to enhance anthracene solubility. The feasibility of reusing the aqueous phase, containing the laccase-mediator system was tested in three consecutive cycles of 24 h with an initial laccase activity of 1200 U/L and 1 mM of the mediator 1-hydroxybenzotriazole (HBT). In the first cycle, total degradation of anthracene took place at a high conversion rate: 16 mu mol/L(R)h. The degree of removal achieved in two subsequent cycles with no extra addition of laccase or HBT were 68 % and 40 % for a laccase activity of 150 and 90 U/L in each cycle respectively. These results proved the potential of a TPPB including a surfactant for the removal of poorly soluble compounds by the enzyme laccase and the possibility of exhausting the oxidative potential of the aqueous phase in consecutive cycles to minimize consumption of both laccase and the mediator.
Transformation Products of Emerging Contaminants in the Environment, 2014
ABSTRACT Natural and synthetic endocrine disrupting chemicals (EDCs) are released into the enviro... more ABSTRACT Natural and synthetic endocrine disrupting chemicals (EDCs) are released into the environment, mainly through sewage treatment systems, before reaching the receiving bodies. It is crucial to maintain ongoing efforts to develop, validate and/or update the current approaches for the effective removal of EDCs. White-rot fungi (WRF) secrete mediators of high molecular weight, increasing the range of compounds potentially biodegradable. The enzymatic membrane reactor (EMR) configuration detailed in this chapter consists of a continuous stirred tank reactor coupled to an ultrafiltration polyethersulfone membrane with a nominal molecular weight cut-off of 10kDa, which allows the recovery and recycling of the enzyme to the reaction vessel. The most common transformation products (TPs) from advanced oxidation processes (AOPs) are obtained by the breakdown of the EDC structure, yielding molecules with lower molecular weight than that of the parent compound and reduced estrogenic activity.
The goal of this study is the development of a system based on the use of the ligninolytic enzyme... more The goal of this study is the development of a system based on the use of the ligninolytic enzyme Manganese Peroxidase (MnP) for the degradation of polycyclic aromatic hydrocarbons (PAHs), of which anthracene was selected as an example. A main problem of these compounds is their poor solubility in aqueous media. Therefore, the addition of different water miscible organic solvents
In this chapter, the engineering aspects of processes catalyzed by peroxidases will be presented.... more In this chapter, the engineering aspects of processes catalyzed by peroxidases will be presented. In particular, a discussion of the existing technologies that utilize peroxidases for different purposes, such as the removal of recalcitrant compounds or the synthesis of polymers, is analyzed. In the first section, the essential variables controlling the process will be investigated, not only those that are
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