## 4 Discussion
It should also be emphasized that the cheese samples were made from unpasteurized, raw goat's milk, which was not free of native microbiota. However, even in the control sample, the acid whey was added to control the fermentation process. The endogenous microbiota can grow in the milk during fermentation, next to the starter cultures; however, carefully selected starter cultures of bacteria strains are able to dominate during the milk's fermentation [54]. Lactobacillus (predominantly _Lactobacillus brevis, Lactobacillus plantarumum, Lactobacillus paracsei_ and _Lactobacillus casei_) constitute the majority of nonstarter lactic acid bacteria in Cheddar, creamy, and some artisanal cheeses. Typical counts of _Lactobacillus_ cells range from 10 to about 10\({}^{8}\) CFU/g of the cheese samples [55; 56; 57]. In comparison, [PERSON] et al. [58] used _L. brevis_ as a probiotic starter culture and found that counts of LAB during 30 days of storage period were approximately 9-6 log CFU/g. Although, in our study, we do not provide the identification of the LAB, the changes in the chemical and physical properties, as well as the texture and sensory characteristics, were observed in samples with _L. brevis_ B1 and _L. plantarum_ Os2, in comparison to the AW control. These observations gave an initial proof of domination of the selected starter cultures and could be a premise for further research. We have found that the level of Enterobacteriaceae in the final product was very high (5.57-6.66 log CFU/g), which suggests the need to improve the hygienic condition of the process. The important observation is that the presence of the Enterobacteriaceae family was successfully reduced during storage. On the other hand, the samples were free of _Listeria monocytogenes_ and _Salmonella_ spp., which was in line with the UE regulation [53], as well as the studies by [PERSON] et al. [9], [PERSON] et al. [59], [PERSON] et. al. [60] and [PERSON] et al. [50]. Moreover, the selected bacterial strains _L. brevis_ B1 and _L. plantarum_ Os2 possess strong antibacterial properties [19; 20]. The isolation of the LAB strains with anti-microbiological, mainly anti-listerial activity from artisanal cheese samples is quite common [16], which could be the reason of the phenomenon. Microbial dynamics in cheese are affected by several factors, such as milk composition, salting, starter culture, renet addition, temperature, relative humidity (85-97%), pH, redox potential, water activity and moisture [61]. Among the several factors that influence the physicochemical properties of cheese, the acidity is crucial as it directly affects the stability of casein micelles and milk minerals [62]. In our study, the pH value was in the range of 5-6, which is the typical value for most cheese varieties [52], however, it was lower than in study of [PERSON] et al. [63]. The differences in the pH values could be caused by the different composition of the starter cultures and their interaction. After 1 month of storage, a significant (\(p<0.05\)) increase in pH was observed, which may have been caused by the utilization of lactic acid, the formation of a non-acid decomposition product and the release of alkaline protein decomposition products [64; 65]. Both the starter bacteria used, _L. plantarum_ Os2 and _L. brevis_ B1, are heterofermatteric LABs that use the phosphoketolase pathway to produce a mixture of lactic acid, ethanol, acetic acid and CO2 as products of hexose fermentation [55]. These bacterial strains represented a similar slight acidification model, however, the Os2 strain seems to be more effective as the TA value after 2 months of storage was the highest in the samples of cheeses fermented with the _L. plantarum_ Os2 strain. In addition, the oxidation-reduction potential increased during storage in all samples and was higher than in the study by [PERSON] et al. [66] where cheeses such as Camembert, Cheddar and Comte reached an ORP between 100 and 350 mV.