Objective: To assess the relief effect of beta-galactosidase genetically engineered Lactococcus lactis on the cell toxicity caused by lactose in vitro.
Methods: An in vitro toxic Caco-2 cell model caused by lactose was established to evaluate the relief effect of beta-galactosidase genetically engineered Lactococcus lactis. Cell morphological parameters and proliferation activity parameter were used.
Results: The in vitro toxic Caco-2 cell model caused by lactose was successfully established; the genetically engineered Lactococcus lactis constructed in the authors' laboratory could enable the Caco-2 cell to have normal appearance with the presence of lactose and could improve the proliferation activity with the presence of high concentration of lactose (P < 0.01).
Conclusion: The beta-galactosidase genetically engineered Lactococcus lactis has significant relief effect on the cell toxicity caused by lactose in vitro, which lays a foundation for food-grade alternation of this bacterium.