Bacteriocin production by Bacillus licheniformis strain P40 in cheese whey using response surface methodology

Abstract

In this work, a 2 3 factorial design was performed with the aim of optimizing the bacteriocin production by Bacillus licheniformis P40, using response surface methodology (RSM). The bacteriocin production was first tested on different byproducts, like feather meal, grape bagasse, an industrial fibrous soybean residue and cheese whey. Cheese whey was the selected medium to test the effect of three variables (temperature, initial pH and whey concentration) by RSM. Statistical analysis of results showed that, in the range studied, the three variables have a significant effect on bacteriocin production. Response-surface data showed maximum bacteriocin production at initial pH between 6.5 and 7.5 and temperature between 26 and 37 °C when the cheese whey concentration was 70 g l −1. Increasing whey concentration resulted in increase of bacteriocin production, with an activity at the maximum whey concentration tested. It was not possible to determine a relation between bacteriocin production and optimal conditions for bacterial growth.