PRODUCTION OF BETA-GALACTOSIDASE BY STREPTOCOCCUS-SALIVARIUS SUBSP THERMOPHILUS 11F

The production of beta-galactosidase by an autolytic strain of Strepto coccus salivarius subsp thermophilus 11F was investigated in batch and fed-batch 2-L working volume stirred tank bioreactors, beta-Galactosi dase was released into the medium upon cell lysis within 1-2 h after t he maximum biomass quantity was reached. In batch fermentations the hi ghest beta-galactosidase activity of 69 U ml(-1) was obtained when the temperature was increased to 42 degrees C after a 4-h growth period a t 30 degrees C, In fed-batch experiments the highest beta-galactosidas e activity of 74 U ml(-1) was obtained at a constant 37 degrees C.