Extracellular production of lipoxygenase from Anabaena sp. PCC 7120 in Bacillus subtilis and its effect on wheat protein.

In this study, the lipoxygenase (ana-LOX) gene from Anabaena sp. PCC 7120 was successful expressed and secreted in Bacillus subtilis. Under the control of the P43 promoter, with a signal peptide from the B. subtilis 168 nprB gene, and facilitated by the molecular chaperone PrsA, the production of the recombinant ana-LOX (ana-rLOX)reached 76 U/mL (171.9 μg/ml) in the supernatant. The purified ana-rLOX was investigated for its effect on dough protein. Ana-rLOX treatment decreased free sulfhydryl groups, increased glutenin macropolymer content, promoted the formation of covalent bonds between gluten protein, and affected protein crosslinking. The results indicated that large aggregates involving gliadin and glutenin were formed. The glutenin macropolymer played a role in the formation of the dough network structure through the exchange of thiol disulfide bonds and the formation of hydrogen or hydrophobic bonds with other proteins.