## 3 Results and Discussion
### Antibacterial and Antifungal Activity of Bacillus amyloliquefaciens \(\mathrm{M}\)
Similarity was found in the fractional profiles of peak I and peak II. Both peaks had a fraction with the same molecular weight--Mw = 26 kDa, and its share in peak I was 4 times higher than in peak II (9.31% in peak I versus 2.29% in peak II). As the elution progressed, the number of fractions in the last two peaks decreased, and while two fractions (Mw = 27 and Mw = 33 kDa--60.78% and 39.22%, respectively) in peak III were detected (Figure 4b), only one fraction with a molecular weight of 22 kDa remained in peak IV (Figure 4c), and it accounted for 100% share. Figure 4: (**a**) Proportional contribution of individual protein fractions to the total protein profile (TPP) of peak II. (**b**) Proportional contribution of individual protein fractions to the total protein profile (TPP) of peak III. (**c**) Proportional contribution of individual protein fractions to the total protein profile (TPP) of peak IV. (**d**) Proportional contribution of individual protein fractions to the total protein profile (TPP) of peak I. The numbers on the individual bars of the histograms indicate the molecular weight of the respective fraction. In general, the lower molecular weight fractions predominated in the sample subjected to gel chromatography separation. Cultivation of B. amyloidosisetaiens M in a Laboratory Bioreactor and Determination of the Kinetic Parameters of the Process  
To obtain antifungal preparations, the strains must allow cultivation with the formation of a significant amount of spores (above \(10^{9}\) cfu spores/cm\({}^{3}\)). A mandatory condition for achieving a high concentration of spores is the research and optimization of the cultivation process. This goal cannot be successfully achieved if the maximum specific growth rate, the time to reach maximum vegetative cell productivity, and the sporulation rate are not known. The kinetic characteristics of the culture determine the optimal duration, management, and regulation of the process, resulting in products with a high concentration of spores. Therefore, a batch cultivation process of _Bacillus amyloliquefaciens_ M was carried out in a laboratory bioreactor with mechanical stirring and a constant concentration of dissolved oxygen. The changes in the biomass, the concentration of spores, the redox potential, and the pH were monitored. Mathematical modeling of the kinetics of biomass accumulation and sporulation was performed (Figures 5-8). Mathematical models are valuable and help in the rational design of production plants, for scaling up, and management of the production process. Kinetic models make it possible to study the complex biochemical processes occurring in cells and their interrelationships [41]. The strain was characterized by a short lag phase of 1.5 h (Figure 5). The culture then entered the exponential growth phase, during which it grew with a very high maximum specific growth rate \(\mu_{\text{m}}=0.739\) h\({}^{-1}\) and a low intrapopulation competition coefficient of 0.057 logN/cm\({}^{3}\cdot\)h. This indicates that the conditions in the bioreactor are suitable for the growth of the strain. This was due to the rapid entry of the strain into the stationary phase (as early as the 12 th h), when a high concentration of vegetative cells (around \(10^{13}\) cfu/cm\({}^{3}\)) was achieved. A study on the presence of spores at the 12 th h was conducted, but no spores were found. As can be seen from Figure 1, the concentration of vegetative cells remains initially constant; therefore, the theoretical duration of the process was calculated, and the time at which the maximum concentration of vegetative cells would be reached was determined. Accurate determination of process duration is essential when scaling up in industrial settings, as it determines production costs.