ABSTRACT
Modern lactic starter technology is a highly competitive, multimillion-dollar sector of today's cheese industry. More literature exists on milk fermentative organisms than for any other food. Several excellent review articles have been written detailing the history of starter cultures. This chapter discusses the use of the homofermentative, mesophilic lactic streptococci Streptococcus lactis and Streptococcus cremoris in hard and soft cheesemaking. Also discussed are thermophilic lactic starters. These starter cultures serve several important functions in the cheesemaking process including initiation of the fermentation process, inhibition of potentially pathogenic organisms, enhancement of cheese keeping quality, direct and indirect contributions to cheese flavor and aroma, and the stabilization of milk in the form of cheese. Successful cheesemaking relies on the conversion of milk sugars to lactic acid by starter bacteria. It is uncontested that bacteriophage infection of starter cultures represents the most challenging problem to the cheese industry, as well as the greatest source of economic loss.
