Optimization of enterocin AS-48 production on a whey-based substrate

This study demonstrates the optimization of AS-48 production by strain Enterococcus faecalis A-48-32 using a whey-derived substrate, Esprion-300 (E-300). To optimise AS-48 production, various factors such as E-300 concentration, glucose, pH and inoculum size were adjusted. The following optimal conditions were established: a growth medium comprising 5% E-300 and 1% glucose, inoculated with 8% producer strain and incubated at 28 degrees C with a controlled pH of 6.55. Under these conditions a maximum activity of 360 AU mL(-1) was attained after 18 h and remained relatively constant for 24 h. The critical factors for optimal AS-48 production in this medium were the pH stabilization at 6.55, in addition to a 1% glucose concentration. (C) 2008 Elsevier Ltd. All rights reserved.