Stabilisation of recombinant aequorin by polyols: activity, thermostability and limited proteolysis.

The photoprotein aequorin is a calcium-dependent bioluminescent enzyme which is most widely used in biotechnology processes, but this protein is susceptible to aggregation and proteolysis degradation. Various additives such as polyols are known to enhance the stability of proteins and protect them in native folded and functional state. In this work, for study of aequorin stability, the histidine-tagged apoaequorin was expressed in Escherichia coli and purified by nickel chelate affinity chromatography.

Continuous biodegradation of parathion by immobilized Sphingomonas sp. in magnetically fixed-bed bioreactors and evaluation of the enzyme stability of immobilized bacteria.

Magnetically-modified Sphingomonas sp. was prepared using covalent binding of magnetic nanoparticles on to the cell surface. The magnetic modified bacteria were immobilized in the fixed-bed bioreactors (FBR) by internal and external magnetic fields for the biodetoxification of a model organophosphate, parathion: 93 % of substrate (50 mg parathion/l) was hydrolyzed at 0.

Immobilization of magnetic modified Flavobacterium ATCC 27551 using magnetic field and evaluation of the enzyme stability of immobilized bacteria.

The magnetic modified Flavobacterium sp. was prepared by covalently binding carboxylate-modified magnetic nanoparticles, and also, ionic adsorption of magnetic Fe(3)O(4) nanoparticles on the cell surface. The magnetic modified bacteria were immobilized by both internal and external magnetic fields.

Purification of L-lysine in simulated moving bed and fixed-bed chromatography.

L-Lysine was produced by a microbial process utilizing a Corynebacterium glutamicum (ATCC 21799) strain. L-Lysine was purified from the cultivated medium by fixed-bed and simulated moving bed (SMB) chromatography. The separation conditions including pH, eluent concentration and Lys+ and Lys2+ adsorption isotherms were studied in batch adsorption.