Evaluation of autochthonous Lactococcus lactis subsp. lactis strain as a candidate starter culture in white-brined cheese

Lactococcus lactis subsp. lactis NCCB100539 isolated from an artisanal raw ewe's milk cheese was evaluated as a potential starter culture in white-brined cheese. As a safety criteria, the cytotoxicity of the viable and heat-killed cells and CFE of this strain were determined on Caco-2 cell line by MTT assay. The antibiotic sensitivity of the strain to nine different antibiotics was also investigated. Cheeses produced using this strain were compared with control cheese in terms of physicochemical, microbiological, sensory properties as well as the peptide and volatile profiles during the 90-days of ripening period. Experimental cheeses had more extensive proteolysis as well as higher sensory scores. Incorporated L. lactis also led to an improvement in the microbial cheese quality. Neither living nor the dead cells and CFE of the strain showed cytotoxicity on Caco-2 cells. Therefore, L. lactis NCCB100539 strain could be a good starter candidate for the industrial white-brined cheeses.

Automated summary

Lactococcus lactis subsp. lactis NCCB100539 strain isolated from artisanal raw ewe's milk cheese showed potential as a starter culture for white-brined cheese. The strain was evaluated for safety and antibiotic sensitivity, and cheeses produced with the strain exhibited improved proteolysis, sensory scores, and microbial quality. Neither live nor dead cells and CFE of the strain showed cytotoxicity. Therefore, L. lactis NCCB100539 could be a suitable starter candidate for industrial white-brined cheeses.