Obiettivo DEVELOPMENT OF A NEW METHOD WHICH ALLOWS AVAILABILITY OF OXYGEN TO THE CELL MICROENVIRONMENT IN A BIOREACTOR. THIS AVOIDS GAS BUBBLING AND HIGH STIRRER SHEAR STRESSES WHICH ARE UNSUITABLE FOR MANY MODES OF IMMOBILIZATION. IT ALSO WILL IMPROVE OXYGEN SUPPLY TO IMMOBILIZED CELLS, WHOSE PRODUCTIVITY DEPENDS ON HIGH OXYGEN AVAILABILITY. Microenvironmental factors are of major importance for reaction kinetics and productivity of immobilized biocatalysts. However, only little is known about the structure of the microenvironment and its controlled change to improve biocatalytic process. Thus, microenvironmental effects of oxygen were investigated, a definite factor of basic and industrial relevance. A defined microenvironment was created around microorganisms with regard to oxygen. The possiblity of oxygen supply to living cells by coimmobilization of the cells with catalase and addition of hydrogen peroxide as an oxygen donor was also examined. 2 examples were chosen: production of bacitracin by Bacillus licheniformis and formation of ergot alkaloids by Claviceps purpurea. The work involved detailed investigation of the constituents of the 2 complex systems and tests in different reactors in which the 2 biocatalysts were kept in the coimmobilized state. The microbial production of bacitracin and ergot alkaloids depended on oxygen available in the microenvironment of the screening organisms. The concept of influencing the microenvironment was found to be considerably affected by multiple interactions between microorganisms, enzymes, substrates and products. Complementarity of the biocatalysts was achieved and the feasibility of supply oxygen to microorganisms via hydrogen peroxide and catalase was demonstrated. However, the following limitations were found: operational instability of catalase and toxicity of peroxide in some of the configurations tested.COIMMOBILISATION OF CATALASE AND BACILLUS OR CLAVICEPS SPECIES. STUDY OF PHYSICO-CHEMICAL INTERACTIONS AND CONTROL OF THE DISTRIBUTION IN SPACE. OPTIMIZATION OF BACITRACIN AND ALCALOID PRODUCTION. IN PARTICULAR : 1- CELL SURFACE PROPERTIES WILL BE CHARACTERIZED AS WELL AS ITS INTERACTION WITH CATALASE. 2- ABSORPTION OF CATALASE ON SPACER COLLOIDAL PARTICLES WILL BE STUDIED. 3- SIMULTANEOUS IMMOBILISATION OF CELLS AND CATALASE ON SOLID SUPPORT BY INTERFACIAL FORCES. Campo scientifico engineering and technologyenvironmental biotechnologybioremediationbioreactorssocial scienceseconomics and businesseconomicsproduction economicsproductivitynatural scienceschemical sciencescatalysisbiocatalysisnatural sciencesbiological sciencesmicrobiologynatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes Programma(i) FP1-BAP - Multiannual research action programme (EEC) in the field of biotechnology (BAP), 1985-1989 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore UNIVERSITE CATHOLIQUE DE LOUVAIN Contributo UE Nessun dato Indirizzo UNITE DE CHIMIE DES INTERFACES PLACE CROIX DU SUD 1 1348 LOUVAIN-LA-NEUVE Belgio Mostra sulla mappa Costo totale Nessun dato Partecipanti (1) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto AACHEN UNIVERSITY OF TECHNOLOGY Germania Contributo UE Nessun dato Indirizzo Templergraben 55 52056 AACHEN Mostra sulla mappa Costo totale Nessun dato