Lactococcus lactis is a non-pathogenic lactococcus researched thoroughly and put into many applications. It has several fermentative pathways, but the most important purpose is its property to manufacture dairy product such as cheese and milk. Lactococcus lactis specializes in lactate dehydrogenase excreting lactic acid, which is used to preserve food and extend food shelf life. Dairy industries continue to improve the activities and effectiveness of L. lactis by manipulating its environment and cell behavior.

Another study utilizes the simple and harmless bacteria as mucosal vaccine. In developing countries where vaccines are limited and not affordable, diseases can spread easily. Researchers attempt to prove that a mucosal vaccine against Streptococcus pneumoniae using Lactococcus lactis is more effective than vaccination with purified live antigen. L. lactis is treated to recombine vaccine strains, so the cell can express the vaccine protein PspATIGR4. The result shows that L. lactis has more potential and safety in developing vaccine in human and should be considered to be used against more pathogens.