Continuous production of a hybrid antibiotic byStreptomyces lividans TK21 pellets in a three-phase fluidized-bed bioreactor

Abstract

The continuous production of a hybrid antibiotic by a transformed strain of Streptomyces lividans TK21 in a three‐phase fluidized bed is studied. Cell aggregates, known as pellets, are used as immobilized cell particles in the bioreactor. A methodology to prepare pellets of a suitable size and morphology is developed. The continuous production of the antibiotic is studied on the basis of decoupling cell growth and antibiotic production, by means of phosphate limitation in the growth medium. The best results are achieved at D = 0.021 h1, with alternate feeding of 0 and 0.05 m M phosphate media. Continuous production of the antibiotic can be maintained at satisfactory levels for periods of 60 days, and stable operation of the bioreactor is achieved during 85 days. Finally, the evolution of the internal structure of the pellets during continuous fermentation is studied. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 601–610, 1997.

Multi-omic characterisation ofStreptomyces hygroscopicusNRRL 30439: detailed assessment of its secondary metabolic potential

“…An initial death phase in the centre of the pellet results in growth arrest, and a secondary metabolic phase of inward-growing multinucleated mycelium is associated with the production of commercially attractive antimicrobial metabolites. 52–56 While likely dependent on the strain, these morphological changes are often difficult to distinguish in suspension culture, yet they are important as they determine the fate of the production phase.…”