cow's milk cheese via real-time polymerase chain reaction assay In 2017, there was a study involving the development of a real-time polymerase chain reaction (qPCR) assay for quantifying Lactobacillus delbrueckii subsp. bulgaricus as well as Streptococcus thermophilus in cow's milk cheese. The goal of this study was to create a way to identify and quantify Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, two lactic acid producing species crucial to the fermentation and ripening of cheese, in a timely manner through the use of qPCR. Two essays using lacZ gene targeting PCR primers resulted from this study and were deemed compatible with the two lactic acid bacteria (LAB) species. This allowed for the direct quantification of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in cheese produced from unpasteurized cow's milk. Effects of Lactobacillus delbrueckii subsp. bulgaricus on antigenicity of milk proteins A study in 2012 posed the question of whether or not Lactobacillus delbrueckii subsp. bulgaricus had any effect on the antigenicity of four kinds of milk proteins, being α-lactalbumin (α-LA), β-lactoglobulin (β-LG), α-casein (α-CN), and β-casein (β-CN). These proteins are the main proteins found in cow's milk and are known to have antigenic properties in humans, especially young children and infants. 2–5% of young children and infants experience cow's milk protein allergy (CMPA), which has harmful effects on their development and may even result in death. This allergy is facilitated through the antigenicity of the milk proteins, which is the ability of the proteins to trigger an immune response in the body that can result in a number of possible allergic reactions. The study was performed by simulating digestion of unfermented milk and milk that was fermented through exposure to Lactobacillus delbrueckii subsp. bulgaricus to compare their antigenicities in order to see if fermentation had any effect on the antigenicity of the proteins. The antigenicities were measured through an enzyme-linked immunosorbent assay (ELISA). The results claimed that the fermentation of cow's milk by Lactobacillus delbrueckii subsp. bulgaricus reduced the antigenicity of α-LA and β-CN. However, it also increased the antigenicity of α-CN while β-LG was not impacted. Subcellular membrane fluidity of Lactobacillus delbrueckii subsp. bulgaricus under cold and osmotic stress The efficiency of lactic acid bacteria cryopreservation is not consistent and may lead to cell death. Lactobacillus delbrueckii subsp. bulgaricus has adapted to defend against cold stress. The way most cells react to the cold is by changing the fluidity