title: Optimization of nisin production by Lactococcus lactis.
abstract: 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).
authors.affiliation: Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Science, University of São Paulo, SP, Brazil. tcvpenna@usp.br
authors.forename: Thereza Christina Vessoni
authors.initials: TC
authors.lastname: Penna
authors.forename: Dante Augusto
authors.initials: DA
authors.lastname: Moraes
mesh_terms: 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
chemical_list: D003470:Culture Media; D010710:Phosphates; D009561:Nisin; D013395:Sucrose; D001216:Asparagine