INTERACTIONS AMONG THERMOPHILIC LACTOBACILLI DURING GROWTH IN CHEESE WHEY

The starters used in the Parmesan cheese technology are whey-cultured, mixed strain cultures of thermophilic rod lactic acid bacteria. In mi xed strain cultures, interactions among different strains can result i n both stimulatory or inhibitory effects on microbial growth rate and metabolic activity. These effects, studied by the use of conductance, were observed for individual strains of thermophilic lactobacilli, whi ch were grown in whey and in the presence of cell-free supernatant flu ids from whey cultures of other strains. The importance of whey as a g rowth medium on the microbial composition of the whey cultures is disc ussed.