## 3 Results and Discussion
### One-Step Analysis of Competitive Growth  
By combining co-culture primary growth models with secondary growth and survival models in one step, we were able to describe the growth patterns of three microbial populations in this work. As presented in Figure 1 for _E. coli_ BR in milk and milk with 1% NaCl, respectively, the following similar characteristics can be recognised. First, LAB played a dominant role in co-cultures; grown at the highest rates that were influenced mostly by the temperature and only partly by 1% NaCl content. [PERSON] et al. [46] and [PERSON] et al. [47] reported a comparable trend regarding the influence of temperature and water activity on the behaviour of LAB. On average, they reached maximum population density (MPD) of 9.32 \(\pm\) 0.07 logs and a stable population increase (the difference between MPD and \(N_{0}\)) of 3.2 \(\pm\) 0.3 log CFU/mL in all co-culture trials in the shortest time. These results aligned with our previous work [19] and those reported for the co-culture growth of _Lactiplantibacillus plantarum_ with _S. aureus_ by [PERSON] et al. [48]. While grown independently, LAB determined the responses of _E. coli_ BR that increased the numbers in 1.23 \(\pm\) 0.32 log CFU/mL for a period in which LAB reached the early stationary phase. _E. coli_ reached its stationary phase with a maximum population density (MPD) of 3.91 \(\pm\) 0.18 logs on average and prolonged its duration with increasing temperature in both cases of milk (without and with 1% NaCl). Consistent with these results, [PERSON] and [PERSON] [49] reported final counts of _E. coli_ 3544 less than 3 logs CFU/mL during co-cultivation with _Lactobacillus acidophilus_ SBT2071 in semi-skimmed sheep's milk. Referring to the increase in population, this was not the case for _G. candidum_. However, in milk, as well as at 1% NaCl, its population reached the highest increase of 4.19 \(\pm\) 0.16 logs, for a longer period than other populations. Naturally, this period was determined by temperature. It can also be seen that the _G. candidum_ lag phase was almost identical to the period that covers the LAB lag and exponential phases together. The growth studies [24,50] demonstrated a similar pattern of growth responses during _G. candidum_ and LAB Fresco co-culturing experiments. During the stationary phase, the yeast was able to grow exponentially and reach its stationary phase. This can be explained by both lactate consumption and ammonium production [51], which are related to an increase in pH and tolerance to lactic acid produced by LAB. Similar responses were also found in co-culture trials, in which the previous isolate of _E. coli_ was replaced by the PS2 isolate isolated from Slovakian artisanal steamed and stretched Slovakian cheese. Compared to BR isolate, the only visually recognisable differences are referred to as a higher MPD and population increase of 4.76 \(\pm\) 0.26 log and 1.91 \(\pm\) 0.33 log, respectively, as well as longer durations of stationary phases in general (Supplementary Figure S1). Thus, naturally, the PS2 isolate also grew at a negligible higher rate than the BR isolate during the exponential phase. The _S. aureus_ isolate 14733 in the same type of co-cultures with LAB and _G. candidum_ reached MPD and a population increase of 3.97 \(\pm\) 0.36 and 1.06 \(\pm\) 0.29 log, respectively (Figure 2). Both mean values were close to the responses of the _E. coli_ BR isolate. Figure 1: Co-culture growth of LAB Fresco, _E. coli_ BR, and _G. candidum_ in milk at 15, 18, and 21 \({}^{\circ}\)C (without and with 1% NaCl, respectively). The continuous lines represent the growth predicted values by the H-GD model and the dots represent the experimental values (\(\blacksquare\) LAB, **A** Ec, \(\bullet\) Gc). The second _S. aureus_ isolate 2064 [52] was also used in the last series of co-cultures with LAB and _G. candidum_.