PERMEABILIZED STREPTOCOCCUS-THERMOPHILUS IN THE PREPARATION OF LOW-LACTOSE MILK

Several compounds with detergent activity were used to permeabilize St reptococcus thermophilus and allow a high level expression of intracel lular beta-galadosidase. Treatment with SDS, Triton X-100, sodium deox ycholate and oxgall suppressed cell growth for several hours, which pe rmitted the use of permeabilized S. thermophilus biomass in milk witho ut concomitant production of lactic acid. The addition of cell prepara tions directly or entrapped in an agarose-gel support resulted in up t o 90% or higher reduction of lactose content in milk.