ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary The influence of inorganic phosphate and immobilization on cells of Claviceps purpurea strain 1029/N5 producing ergot peptides in shake culture was examined. Immobilization in Ca-alginate beads resulted in a marked reduction of some metabolic activities, i.e. the periods of alkaloid formation and cell growth were prolonged. High concentrations of inorganic phosphate (1 g/l KH2PO4) could reduce or stop alkaloid formation both by free and immobilized cells at any time during fermentation. The optimum phosphate concentration for alkaloid production by immobilized cells (about 0.5 mM) was a quarter of that required by free cells. This optimum shift was attributed to (i) the diminished phosphate demand of immobilized cells, due to their reduced metabolic activities, and (ii) the phosphate-dependent morphological behaviour of the biocatalyst. The observed decrease in alkaloid concentrations during later periods of the fermentation supported the idea of alkaloid-degradative enzymes, activated by high phosphate concentrations. Immobilization showed an advantageous influence on this undesirable effect.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00176524
