title: Ammonium ion affecting tylosin production by Streptomyces fradiae NRRL 2702 in continuous culture.
abstract: Nitrogen regulation in tylosin production by Streptomyces fradiae NRRL 2702 was studied in chemostat culture using a soluble synthetic medium. The maximum value of specific tylosin formation rate (qTYL) was 1.13 mg g-1 h-1 at the specific growth rate (mu) of 0.05 h-1, and qTYL decreased with increasing levels of the specific growth rate after reaching a rate of 0.1 h-1. The optimum conditions for tylosin formation were that the specific ammonium ion uptake rate (qN) and mu were 0.13 mmol g-1 h-1 and 0.05 h-1, respectively. The specific formation rates of threonine dehydratase (TDT) and tylosin were repressed by high levels of specific ammonium ion uptake rate. This study showed the adaptation to chemostat cultures of the nitrogen regulation of tylosin fermentations.
authors.affiliation: Department of Genetic Engineering, Youngdong Institute of Technology, Chungbuk, South Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D013302:Streptomyces / Q000378:metabolism*; D015645:Tylosin / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D000644:Quaternary Ammonium Compounds; D015645:Tylosin