ABSTRACT
This article outlines some of the factors influencing the choice of a suitable reactor for using immobilized biocatalysts. We have concentrated on biochemical engineering parameters of immobilized biocatalysts, which are important with respect to their application in industrial processes.
Subject(s)
Catalysis , Enzymes, Immobilized , Biomedical Engineering , Carrier Proteins , KineticsABSTRACT
Complete design of the optimum immobilized biocatalyst seems to still be a matter of the future. To be successful, it would require numerical determination of all significant parameters at each enzyme engineering phase, that is at the design of the carriers, immobilized biocatalysts and immobilized reactors. Future research trends should follow this strategy. For processing, cellulosic materials have been considered carriers that fulfill requests to an example model: they represent a unique family of carriers that cover a broad variety of physical and chemical properties, immobilizing techniques, and immobilized reactors as well. The reason for writing this review article was to test the reliability of such a processing and subsequently, to confront theoretical considerations with practical applications of biocatalysts immobilized on cellulose materials.
Subject(s)
Biotechnology/methods , Catalysis , Cellulose , Indicators and Reagents , Kinetics , MicrospheresABSTRACT
The growth and activity of formate dehydrogenase (FDH) in five methanol-utilizing yeasts at various methanol concentrations were investigated. The parameters observed were inhibited at 4% methanol concentration in the medium. For Candida boidinii and Pichia trehalophila FDH activity was not found. The highest value was detected for Pichia lindneri (0.14 U/mg protein).
Subject(s)
Candida/enzymology , Formate Dehydrogenases/metabolism , Methanol/pharmacology , Pichia/enzymology , Candida/drug effects , Candida/growth & development , Culture Media/chemistry , Pichia/drug effects , Pichia/growth & development , Species SpecificityABSTRACT
The possibility of using the enzyme thermistor (ET) for the direct determination of kinetic parameters (Km, Ki, Vm) of immobilized enzyme (IME) was evaluated using different preparations of invertase conjugated to bead celluloses. Two different ET columns packed with IME were operated in the mode of a differential enzyme reactor (short length, low substrate conversion). Kinetic parameters of the above IME reactor were computed by a nonlinear curve-fitting procedure. The obtained kinetic parameters were superverified by means of an independent differential reactor (DR) system. This system utilized an indirect postcolumn analytical method based on determination of glucose concentration in the stirred reservoir. Best agreement between the data acquired by direct (ET) and indirect (DR) methods was obtained if the ET column was operated at flow rates within the range of 1.0-1.5 ml min-1 using invertase-cellulose chlorotriazine conjugate. Influence of heat loss and flow nonideality is discussed. The proposed ET method offers a rapid, convenient, and general approach to determination of kinetic constants of IME preparations by omitting postcolumn analytical methods.
