Whey-Based Bacteriophage Inhibitory Italian Bulk Starter Medium

Six commercially available bulk starter media used for growing rod-coccus thermophilic lactic acid bacteria (e.g.. Lactobacillus bulgaricus and Streptococcus thermophilus) were compared.The media were inoculated at the manufacturer's recommended rate with freshly thawed frozen concentrated thermophilic bulk set cultures obtained from two culture supply houses.Media were tested for bacteriophage inhibition and acid-producing activity of the cells grown in each medium.Cells from the media were rated for thermophilic acid-producing activity by summing the differences between the pH of an uninoculated and 1 and 2% inoculated NOM over a temperature profile simulating Mozzarella cheese manufacture.An experimental whey-based thermophilic bulk starter medium also was evaluated in comparison with those commercially available.