Abstract
Hansenula polymorpha alcohol oxidase (AOX) was immobilised on propylamino-derivatised controlled pore glass (CPG) by covalent attachment using glutaraldehyde (GA) as cross-linker. Different pore and particle sizes were used as well as different experimental conditions (GA concentration, buffer type, pH, time of activation) to optimise the enzymatic productivity and operational stability of the immobilised enzyme. The best results were obtained by activating CPG with 6.5% GA in phosphate buffer, pH 7, for 1 h. The highest activity (0.45 U/mg) and productivity (6.2 mol/m 3 min) were obtained with a CPG support with 120–200 mesh and 550 Å pore size. Mini packed-bed bioreactors (9.4–69 mm 3) with the immobilised AOX, were used to monitor ethanol. The performance of the bioreactors was simulated using a plug flow model. External mass transfer limitations were observed for residence times higher than 2 s. The bioreactors operated continuously at 32 °C for more than 14 h without significant loss of performance (less than 5%). Ethanol in real samples such as beer, brandy and fermentation media was also successfully monitored. Bi-enzymatic bioreactors containing AOX and HRP were further constructed and displayed a similar performance.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.