RESUMO
A review is given on the morphology of Acremonium chrysogenum and the biosynthesis of cephalosporin C based on the published references. Investigations are presented on the comparison of cultivation media carried out by means of shake flask cultures. The process performance of a standard cultivation in well controlled bioreactor is presented and compared with other cultivations, which were executed with the same strain and bioreactor, but with various carbon-, nitrogen- and sulphur-sources keeping the concentrations of the key components at definite levels. Also the influence of dilution and enrichment of the medium on the process performance is explored. Mathematical models for the growth of Acremonium chrysogenum and production of cephalosporin C are reviewed and their application for control of industrial processes with complex cultivation media are discussed.
Assuntos
Acremonium/crescimento & desenvolvimento , Acremonium/metabolismo , Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/métodos , Cefalosporinas/biossíntese , Modelos Biológicos , Acremonium/classificação , Acremonium/citologia , Antibacterianos/biossíntese , Reatores Biológicos/economia , Técnicas de Cultura de Células/economia , Divisão Celular/fisiologia , Cefalosporinas/economiaRESUMO
Process monitoring of cephalosporin C formation by Acremonium chrysogenum in laboratory investigations is considered. The goal of these investigations is the identification of bottlenecks in the biosynthesis and the improvement of the process performance. Based on reports of other research groups and own experience the key parameters were selected, which influence the process performance. They are: dissolved oxygen and pH values. In addition the concentrations of biomass, DNA, glucose and reducing sugars (glucose, maltose, maltotriose and oligosaccharides), methionine, other nitrogen sources (ammonium ion, other amino acids), organic acids, phosphate, sulfate, dissolved organic carbon, proteins, product and precursors in the cell free cultivation medium are monitored. In addition the intracellular concentrations of RNA, DNA, proteins, amino acids as well as the activities of the enzymes of the biosynthesis of cephalosporin C are determined. The influence of these parameters on the biosynthesis is discussed.
