Optimization of cold-adapted alpha-galactosidase expression in Escherichia coli

α-Galactosidase (α-PsGal) of the cold-adapted marine bacterium Pseudoalteromonas sp. KMM 701 was cloned into the pET-40b(+) vector to study its properties and to develop an effective method for modifying human B-erythrocytes into O-blood group. The use of heat-shock as a pre-induction treatment, IPTG concentration of 0.2 mM and post-induction cultivation at 18 °C for 20 h in the developed MX-medium allowed increasing the recombinant Escherichia coli Rosetta (DE3)/40Gal strain productivity up to 30 times and the total soluble α-PsGal yield up to 40 times. •The expression of recombinant alpha-galactosidase α-PsGal from marine bacterium Pseudoalteromonas sp. was optimized.•The parameters for the maximal α-PsGal yield in soluble form in E. coli were selected.•A novel medium MX for the expression in E.coli was suggested for enhancing recombinant soluble protein production.