[Regulatory effects of ammonium ions on the biosynthesis of meilingmycin].
Based on the effects of different ammonium sulfate concentrations on meilingmycin biosynthesis, the results show that lower concentration of ammonium ions stimulates the biosynthesis of meilingmycin, while the concentration of higher than 5mmol/L inhibits the mycelial growth and the biosynthesis of the products. However, the sugar consumption rate increases with the elevating concentration of ammonium sulfate. On this basis, six enzymes, which are greatly related to the meilingmycin biosynthesis and the glucose metabolism, were measured and analyzed during the meilingmycin fermentation process. The results suggest that glucose-6-phosphate dehydrogenase, citrate synthase, succinate dehydrogenase and fatty acid synthase are stimulated by higher concentration of ammonium ions, while valine dehydrogenase and methylmalonyl-CoA carboxyltransferase are inhibited. From the results it follows that ammonium ions favors primary metabolism, that is, the HMP passway and the TCA circle is enhanced, as well as the source of the precursors for the biosynthesis of meilingmycin is restricted, which bring about the lower production of meilingmycin.
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China. wangping5@126.com
Ping
P
Wang
Ying-ping
YP
Zhuang
Ju
J
Chu
Si-liang
SL
Zhang
D000645:Ammonium Sulfate / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D050260:Carbohydrate Metabolism / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005285:Fermentation; D018942:Macrolides / Q000378:metabolism*; D013302:Streptomyces / Q000187:drug effects / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D018942:Macrolides; C452420:meilingmycin; D000645:Ammonium Sulfate