Increases in Italian cheese consumption have focused attention on the need for additional research into the microbiology and genetics of the lactic starter cultures used in these fermentations. Starter cultures can have a significant impact on the body and texture of cheese, as well as on functional properties such as melting. As knowledge related to the physiology, genetics and general microbiology of thermophilic lactic acid bacteria expands, new strategies are becoming available to improve product quality and broaden product diversity, particularly for reduced-fat cheeses.