Optimization of medium composition for production of lacticin LLC518 by Lactococcus lactis subsp. lactis LLC518 using response surface methodology.

摘要

Response surface methodology (RSM) was applied for the optimization of lacticin LLC518 production, which was produced by Lactococcus lactis subsp. lactis LLC518. Tryptone, KH₂PO₄ and MgSO₄ had significant effects on lacticin LLC518 biosynthesis by a Plackett-Burman design (PBD). After steepest ascent design (SAD) and central composite design (CCD), the optimum medium compositions were obtained as follows (g/l): sucrose 20, yeast extract 5, tryptone 8.18, beef extract 10, MgSO₄.7H₂O 0.82, K₂HPO₄ 2.8, (NH₄)₂HC₆H₅O₇ 5.0, CH₃COONa 5.0, MnSO₄ 0.25 and Tween 80 5 ml. An 86.3% increase in bacteriocin production (180.13 IU/ml) was achieved under this condition compared within unoptimized medium (96.72 IU/ml). Under these optimized conditions, the production of Lacticin LLC518 began at 4 h, peaked at 14 h.