[Culture medium optimization and primary kinetics analysis for nisin production].
Response surface methodology was used to optimize a medium for nisin production of Lactococcus lactis. In the first optimization step the influence of sucrose, soybean peptone, yeast extract, potassium dihydrogen phosphate, sodium chloride, and magnesium sulfur on nisin production was evaluated using a fractional factorial design. Potassium dihydrogen phosphate influenced nisin production positively while soybean peptone affected nisin production negatively. The other components had no significant effect on nisin production. The path of steepest ascent was used to approach the optimal region of the medium composition. In the third step the optimal concentrations of KH2PO4 and soybean peptone were determined by a central composite design and response surface analysis. The optimized medium allowed nisin production to be increased from 1074 IU/mL to 2150 IU/mL. The kinetic analysis showed that nisin production fashion at optimized and non-optimized media was not changed and maintained partially growth-associated. But the specific growth rates and the specific nisin production rates for the strain at the optimized medium were bigger than the ones at the non-optimized medium after the cells entered the middle of exponential phase.
Li
C
C
State Key Laboratory of Biochemical Engineering, Institute of Chemical Metallurgy, Chinese Academy of Sciences, Beijing 100080, China. chanlixyl@hotmail.com
Bai
J H
JH
Cai
Z L
ZL
Ouyang
F
F
D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D003470:Culture Media; D005285:Fermentation; D007700:Kinetics; D013294:Lactococcus lactis / Q000254:growth & development / Q000378:metabolism*; D009561:Nisin / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D003470:Culture Media; D009561:Nisin