Isolation and some properties of β-galactosidase from the thermophilic bacterium Thermus thermophilus

摘要: Abstract The highest β -galactosidase activity in Thermus thermophilus cells was achieved after 40 h of cultivation at 70°C a medium containing 0.8% peptone, 0.4% yeast extract and 0.2% NaCl. After the addition to 2% lactose or galactose, enzyme synthesis increased by about 33% 61% its constitutive value. thermostable isolation partial purification involved extraction 0.01  m phosphate buffer pH 7.2, ammonium sulphate precipitation, dialysis gel filtration on Sephadex G-200 lyophilization. recovery yield during process 72% total value extract. step resulted an increase specific two-fold more than precipitate. crude obtained exhibited pH 6.6 87°C. Decimal reduction times 75, 80, 85, 90 95°C were 174, 50, 22, 5.5 0.9 h, respectively..