The selection of a biocatalyst for the development of a biomimetic CCS processes has several constraints. In particular, Carbonic Anhydrase (CA) must be active and stable at both temperature and ionic strength typical of CO2 absorption units. The present contribution concerns the kinetic assessment of a recombinant CA identified and characterized in the thermophilic bacterium, Sulfurihydrogenibium sp.. This enzyme is thermostable and thermoactive up to 100 °C and is resistant to common protein denaturants. The experimental apparatus consisted of a 2 L stirred cell reactor. The procedure was based on the assessment of absorption rate. The system was previously validated with respect to bovine carbonic anhydrase. Tests were carried out with aqueous solutions characterized by a wide spectrum of composition (NaCO3-NaHCO3, KaCO3-KHCO3, ...). CA concentration was changed over a wide interval. Long-term stability of the recombinant CA was also assayed. Tests with the recombinant CA at 25°C in 0.5 M NaCO3-0.5 M NaHCO3 buffer at pH 9.6 yielded kcat/Km =272 m3/(kg s). Assuming for CA the MW=29kDa, kcat/Km resulted 7.9 109 m3/(mol s). Performances of the recombinant CA were assessed in K2CO3 solutions, one of the aqueous solvent commonly adopted for CO2 absorption on industrial scale. A mass transfer enhancement factor of 4 was assessed at: 20%w K2CO3 solution, carbon loading 1.2, CA concentration of 15 kg/m3 at 25°C. Some tests were carried out with CA immobilized in polyurethane foam granules, as a first attempt at CA immobilization. The enhancement factor of CA immobilized was assessed.
Biomimetic CCS process: performances of a thermostable recombinant carbonic anhydrase / Russo, MARIA ELENA; Olivieri, Giuseppe; Marzocchella, Antonio; Salatino, Piero; C., Capasso; V., De Luca; Rossi, Mose'. - STAMPA. - (2011), pp. 70-70. (Intervento presentato al convegno XXXIV Meeting of the Italian Section of the Combustion Institute tenutosi a Rome nel October 24-26, 2011) [10.4405/34proci2011.III12].
Biomimetic CCS process: performances of a thermostable recombinant carbonic anhydrase
RUSSO, MARIA ELENA;OLIVIERI, GIUSEPPE;MARZOCCHELLA, ANTONIO;SALATINO, PIERO;ROSSI, MOSE'
2011
Abstract
The selection of a biocatalyst for the development of a biomimetic CCS processes has several constraints. In particular, Carbonic Anhydrase (CA) must be active and stable at both temperature and ionic strength typical of CO2 absorption units. The present contribution concerns the kinetic assessment of a recombinant CA identified and characterized in the thermophilic bacterium, Sulfurihydrogenibium sp.. This enzyme is thermostable and thermoactive up to 100 °C and is resistant to common protein denaturants. The experimental apparatus consisted of a 2 L stirred cell reactor. The procedure was based on the assessment of absorption rate. The system was previously validated with respect to bovine carbonic anhydrase. Tests were carried out with aqueous solutions characterized by a wide spectrum of composition (NaCO3-NaHCO3, KaCO3-KHCO3, ...). CA concentration was changed over a wide interval. Long-term stability of the recombinant CA was also assayed. Tests with the recombinant CA at 25°C in 0.5 M NaCO3-0.5 M NaHCO3 buffer at pH 9.6 yielded kcat/Km =272 m3/(kg s). Assuming for CA the MW=29kDa, kcat/Km resulted 7.9 109 m3/(mol s). Performances of the recombinant CA were assessed in K2CO3 solutions, one of the aqueous solvent commonly adopted for CO2 absorption on industrial scale. A mass transfer enhancement factor of 4 was assessed at: 20%w K2CO3 solution, carbon loading 1.2, CA concentration of 15 kg/m3 at 25°C. Some tests were carried out with CA immobilized in polyurethane foam granules, as a first attempt at CA immobilization. The enhancement factor of CA immobilized was assessed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
