STUDIES ON BACTERIOPHAGE IN RELATION TO CHEDDAR CHEESEMAKING

Abstract

The sudden stoppage of acid development in several experimental vats of Cheddar cheese was shown to be due to the activity of a polyvalent streptococcal phage. Although the starter used consisted of a mixture of organisms, the stoppage was as abrupt as that in cases in which single strain starters are employed. Experimental infection of a vat of milk duplicated the original findings and resulted in the production of a cheese of poor body and texture, with a decidedly "fruity" flavour.The presence of phage in the starter itself could not be demonstrated. Tests made on the milk of 18 cows, composite herd samples, stable and laboratory air, and rennet extract failed to indicate specifically the origin of the lytic agent.