Cloning, expression, and purification of a recombinant cold-adapted beta-galactosidase from antarctic bacterium Pseudoalteromonas sp. 22b.

The gram-negative antarctic bacterium Pseudoalteromonas sp. 22b, isolated from the alimentary tract of krill Thyssanoessa macrura, synthesizes an intracellular cold-adapted beta-galactosidase. The gene encoding this beta-galactosidase has been PCR amplified, cloned, expressed in Escherichia coli, purified, and characterized.