Oxygen uptake rate (OUR) guided nitrogen control strategy for improving
nemadectin production by Streptomyces cyaneogriseus ssp.
noncyanogenus
Abstract
Oxygen supply and oxygen uptate rate (OUR) significantly influences both
the physiological state of cells and nemadectin biosynthesis by
Streptomyces cyaneogriseus ssp. noncyanogenus. In this study, a
real-time monitoring approach for nemadectin fermentation was developed
for the first time by an on-line OUR control strategy. The effect of OUR
levels during the mycelium differentiation phase on nemadectin
biosynthesis was studied and optimized by adjusting feeding rates of
(NH4)2SO4. Results
showed that controlling the OUR at approximately 17.5
mmol·L-1·h-1 during the mycelium
differentiation phase effectively enhanced nemadectin production,
reaching 2805.1 μg/mL, making 129.5% increase compared to the control.
This OUR control strategy was successfully scaled-up to a 500 L pilot
scale, achieving the highest ever nemadectin production of 2867.3 μg/mL.
These findings demonstrate that this OUR control strategy provides an
effective and scalable approach for industrial nemadectin production.