Ectoine Production Using Novel Heterologous EctABCS. salarius from Marine Bacterium Salinicola salarius

Ectoine, a heterocyclic amino acid produced by various bacteria, was widely used in the fields of cosmetics and medicine. In this study, novel ectoine synthesis cluster from marine bacterium Salinicola salarius 1A01339 firstly introduced into Escherichia coli BL21(DE3) for heterologous production ectoine. The bioinformatic analysis proved function these enzymes, showed highest identities 83.3–87.7% with enzymes other microorganisms. Using whole-cell biocatalytic method, 3.28 g/L synthesized excreted medium substrate 200 mM sodium aspartate at 25 °C, pH 6.5 flask-level. Further bioconversion performed fermentor system high cell density 20 OD/mL, concentration extracellular increased to 22.5 24 h (equivalent specific productivity 0.94 g/L·h), achieving over 6 times compared that flasks. Significantly, recombinant strain demonstrated lower catalytic temperature optimum stronger tolerance 300 mM. These results might provide compelling case as well potential applications large-scale industrial production.