Presented is the protocol for co-immobilizing whole-cell biocatalysts for cofactor regeneration and improved reusability, using the production of L-xylulose as an example. The cofactor regeneration is achieved by coupling two Escherichia coli strains expressing functionally complementary enzymes; the whole-cell biocatalyst immobilization is achieved by cell encapsulation in calcium alginate beads.
In this study, we present a protocol for cortisol extraction from the fin and jawbone of sturgeon species. Fin and jawbone cortisol levels were further examined by comparing two washing solvents followed by ELISA assays. This study piloted the feasibility of jawbone cortisol as a novel stress indicator.