Low molecular weight liquid media development for Lactobacilli producing bacteriocins

BACKGROUND Contemporary purification techniques of Lactobacilli bacteriocins include chemical precipitation and separation through solvents to obtain highly potent semi‐purified bacteriocins. These methods are laborious and bacteriocin yields are low. To address this problem a set of new, efficient, cost effective media, was created, containing low molecular weight nutrient sources (LMWM). Using these media future separation and concentration of the desired metabolic products, using ultra‐ and nano‐filtration from the cultured broth was possible.RESULTS The LMWM were made through serial filtration (filters varying in pore size 30 kDa, 4 kDa and 1 kDa MWCO) of a modified optimum liquid medium for Lactobacilli growth. The developed media were tested for bacteriocin production and biomass growth, using three known bacteriocin‐producing Lactobacilli strains, Lactobacillus casei NCIMB 11970, Lactobacillus plantarum NCIMB 8014, Lactobacillus lactis NCIMB 8586. All were successfully grown (µ max 0.16 to 0.18 h −1 ) on the LMWM and produced a significant amount of bacteriocins in the range 110 to 130 IU mL −1 .CONCLUSIONS LMWM do support Lactobacilli growth and bacteriocin production, establishing an alternative to the current production nutrient media. The uptake of the nutrient sources is facilitated as nitrogen sources, which were primarily responsible for growth, were supported in less complex forms. Copyright © 2012 Society of Chemical Industry