The invention relates to
cellobiose epimerase (Areu-CE) for catalyzing
lactose conversion at low temperature and application of the
cellobiose epimerase (Areu-CE). The full length of the Areu-CE
gene is 1248 bp, 401 amino acids are encoded, the Areu-CE
gene is purified after being expressed in
escherichia coli, and the molecular weight is about 45 kDa. The
enzyme has the highest activity under the conditions that the pH is 7.0 and the temperature is 50 DEG C, the
specific activity reaches 139.7 U / mg, the Km value is 97.8 mM, and kcat / Km is 1.74 s <-1 >. MM <-1 >. Under the low-temperature condition of 8 DEG C, the conversion rates of the Areu-CE to the epinalactose of 200 mM and 400 mM
lactose both reach 27%, and the Areu-CE shows good
system compatibility in a milk
system. In addition, the half-life period of the
enzyme at 50 DEG C is 5.8 minutes, the
enzyme can be compatible with a
pasteurization process, reaction termination in industrial production is facilitated, and generation of by-products is prevented. The invention also provides a
gene sequence of the Areu-CE, a preparation method of the enzyme and application of the enzyme in production of epinalactose, and the Areu-CE enzyme is especially suitable for the fields of dairy
processing,
cold chain functional
sugar preparation and the like, and has remarkable industrial application prospect and commercial value. The enzyme has the characteristic of efficiently catalyzing
lactose to be converted into epinalactose at low temperature.