Optimization of nisin production by Lactococcus lactis.
The production of nisin by batch culture of Lactococcus lactis ATCC 11454 in MRS broth (pH 6.5), as treated in 30 assays, that were set up by a fractional factorial design of two levels (2[4-1]), was improved. The minimum and maximum concentrations of sucrose (5.0-12.5 g/L), asparagine (7.5-75 g/L), potassium phosphate (6.0-18.0 g/L), and Tween-80 (1.0-6.6 g/L) were added to MRS broth. The best nisin activities ranged from 1.5 x 10(4) to 1.8 x 10(4) arbitrary units (AU)/mL for the maximum levels of sucrose, asparagine, and monobasic potassium phosphate, and for the minimum concentration of Tween-80. The best following proportions between nutrients were adopted as optimum for maximum specific nisin productivity of about 6.0 mg/mg of dry cell weight (related to 2.5 mg of pure nisin preparation with a specific activity of 1.0 x 10(5) AU/mL): C/N = 0.17, C/P = 0.69, N/P = 4.17 (C = sucrose, N = asparagine, P = phosphate, T = Tween-80).
Penna
Thereza Christina Vessoni
TC
Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Science, University of São Paulo, SP, Brazil. tcvpenna@usp.br
Moraes
Dante Augusto
DA
D001216:Asparagine / Q000378:metabolism; D001431:Bacteriological Techniques / Q000379:methods; D003470:Culture Media; D013294:Lactococcus lactis / Q000254:growth & development / Q000378:metabolism*; D009561:Nisin / Q000096:biosynthesis*; D010710:Phosphates / Q000378:metabolism; D012044:Regression Analysis; D013395:Sucrose / Q000378:metabolism
D003470:Culture Media; D010710:Phosphates; D009561:Nisin; D013395:Sucrose; D001216:Asparagine