Glycine feeding improves pristinamycin production during fermentation including resin for in situ separation.

ABSTRACT

Seven amino acids were tested as precursors to affect pristinamycin production by a mutant strain derived from Streptomyces pristinaespiralis ATCC25486. Of those, glycine was selected as the best precursor to facilitate both cell growth and pristinamycin production at the feeding time of 36-h incubation and the feeding rate of 0.75 g L(-1) flask culture. The optimized time and concentration of glycine feeding were applied to enlarged 3-L bioreactor fermentation with a resin added at the time of 20-h fermentation for in situ separation. As a result, a combination of the glycine feeding and the added resin resulted in the maximal pristinamycin yield of 616 mg L(-1) culture 12 h after glycine feeding. The yield from the combined treatment was 1.71-, 2.77- and 4.32-fold of those from the mere glycine and resin treatments and the control, respectively. Other parameters, including intracellular nucleic acid content, animo nitrogen content and pH level, during 72-h fermentation were also given in association with the pristinamycin yields in the different treatments. The results indicate that glycine feeding is an effective approach to enhance pristinamycin production in the culture of S. pristinaespiralis F213 with supplemented resin for in situ separation.