## 4 Discussion
An in vivo anti-staphylococcal effect was previously most frequently noted using other types of bacteriocin-producing strains and/or their bacteriocins, such as, e.g., Enterocin M produced by _Enterococcus ficecium_ AL41 = CCM8558 in broiler rabbits [32]. There also, immune parameter-phagocytic activity was increased. Based on previous [15] technological tests (e.g., no diacetyl production) of the strain MK/3, we decided to test its beneficial parameters, such as postbiotic (bacteriocin) potential. The strain MK1/3 was found to be bacteriocin (postbiotic) active. This testing is still in processing. Postbiotic substance from the strain MK1/3 showed in vitro anti-enterococcal effect. Moreover, in vivo, an anti-staphylococcal effect was also noted. [PERSON] and [PERSON] [33] described the strain _L. lactis_ from fermented milk with anti-staphylococcal activity against the target of _S. aureus_ bacteria. As formerly indicated, in this study, in vivo anti-staphylococcal effect was noted using a mice model studying safety of the MK1/3. [PERSON] et al. [34] even reported _L. lactis_ subsp. _lactis_ from fermented milk with a broad antimicrobial spectrum including _S. aureus_, _E. coli_, and _S. typhimurium_. This strain was similar to ours, tolerating 3% bile and pH 3, which are properties improving the functionality of the selected strain. Anti-staphylococcal and anti-literial effects of bacteriocin produced by _L. lactis_ 808 from fermented food products and fruits were reported by [PERSON] et al. [35]. In general, bacteriocins produced by _Lactococci_ (postbiotic active) usually exhibit a narrow inhibitory spectrum [36]. As reported, in the case of the strain MK1/3, in vitro postbiotic activity testing is still in processing. That is, we cannot recognize at this time if it is a substance with a narrow or a broad antimicrobial spectrum. Other characteristics of the bacteriocin (postbiotic) substance are being processed, hoping to achieve more adequate responses regarding its antimicrobial activity. When fresh goat cheese was made with the strain MK1/3, this type of cheese quality remained. The pH value was not negatively influenced (6.34-4.82). The total counts of presumptive _Lactococci_ reached a high level during processing (from 8.58, through 9.75 CFU/g to 9.41 CFU/g log 10), with the highest count on day 7 (10.10 CFU/g, log 10). The fresh cheese possessed a typical lactic flavor and texture, as well. Similarly, in making the Eidam cheese with the strain MK1/3, the texture and other parameters remained [14]. But growth inhibition of the MK1/3 strain was noted, with increased salt concentration in the medium through 30 h of processing [14,15]. Using 2% concentration of NaCl in the medium does not negatively influence the growth of the strain MK1/3; its growth is still sufficient (A\({}_{600}\)/30 h-2% = 2.157). This indicates the ability of _L. lactis_ MK1/3 to grow in cheeses with the standard and/or higher NaCl content [15,37]. The acceptable salt content, e.g., in Cheddar cheeses, ranged from a normal (1.7%) to high (2.3%) salt content [37]. [PERSON] et al. [36] reported that the species strains represent a culture widely used in salt-containing dairy products. They used the strain _L. lactis_ R-604 to show it to be salt-tolerant in M17 broth, even with 5% NaCl concentration, which is beneficial for its use in salt-containing dairy products. The strain MK1/3's salt tolerance is also beneficial when compared to that for _L. lactis_ R-604. It showed its advantage among the others, e.g., LAB. Temperature is one of the most crucial factors in cheesemaking. It affects all steps of cheesemaking, from curd formation to the final texture and cheese flavor. Cheese ripening or affinage is also the phase where temperature control is vital. Most cheeses are aged at 10-15 \({}^{\circ}\)C with control of humidity. This ensures proper microbial activity leading to flavor and texture development. If the temperature is too warm, cheeses may spoil or develop off-flavors.