适合龟裂链霉菌13C代谢通量分析合成培养基的优化及应用

Optimization and application of chemically defined medium for 13C metabolic flux analysis of Streptomyces rimosus M4018

摘要:

为开发一种适合龟裂链霉菌13C代谢通量分析的合成培养基，以龟裂链霉菌模式菌株M4018为研究对象，比较其在各种有机氮源和无机氮源的生长和土霉素合成特性。首次筛选到以硝酸钾为主要氮源的合成培养基，通过响应面分析法进一步优化，将土霉素合成能力由75.2 mg/L提高到145.6 mg/L。并应用到100%的1-13C葡萄糖标记实验，首次从同位素标记代谢流分析上证实了龟裂链霉菌中不存在2-酮-3-脱氧-6-磷酸葡糖酸裂解途径 (Entner-Doudoroff pathway, ED)，为龟裂链霉菌13C代谢通量分析提供了重要基础。

Abstract:

The aim of this study is to develop a synthetic medium suitable for 13C metabolic flux analysis (13C-MFA) of Streptomyces rimosus. The cell growth rate and oxytetracycline production by S. rimosus M4018 were compared when M4018 cells were growth on the optimized chemically defined media with organic nitrogen sources or inorganic nitrogen sources. First, a synthetic medium contained KNO3 as the main nitrogen source was screened, then optimized by a response surface method. Using this new medium, the oxytetracycline yield was increased from 75.2 to 145.6 mg/L. Furthermore, based on the 13C-MFA, we identified that Entner-Doudoroff pathway does not exist in S. rimosus cells cultured in a chemically defined medium with feed of 100% 1-13C labeled glucose. This study is helpful for subsequent 13C-MFA application of S. rimosus.