Lactose hydrolysis by mutant streptococcus thermophilus

摘要

Mutant strains of Streptococcus thermophilus having defective lactose transport systems having a phenotype gluS.sup.31, lacS.sup.-, sucS.sup.+ and &bgr;gal.sup.+ are effective for use in processes where the hydrolysis of lactose is sought. Thermostability of these strains as well as the &bgr;-galactosidase produced allows lactose hydrolysis prior to and during pasteurization. These organisms provide the food industry with improved methods of making reduced lactose dairy products.