Enhanced expression of active recombinant alginate lyase AlyPEEC cloned from a marine bacterium Pseudoalteromonas elyakovii in Escherichia coli by calcium compounds

Recombinant protein production in Escherichia coli is well suited to applications in the basic and applied sciences due to its associated simplicity, cost-effectiveness and the large number of genetic strategies available. However, the active-form of the marine bacterial enzyme, alginate lyase, was difficult to express in E. coli cells under standard culture conditions. In this study, we found various calcium compounds that enhanced the expression of the active enzyme. The alyPEEC gene encoding extracellular alginate lyase of Pseudoalteromonas elyakovii IAM 14594 was comprised of a 1,197 bp open reading frame encoding 398 amino acid residues with the domain G to N functioning as the mature enzyme. Three clones, pTPB24 with a 2.7 kb insert containing alyPEEC gene and paeX and their respective promoter regions, pTPB31 with a 1.6 kb insert containing only the alyPEEC gene its own promoter, and pCD11