## 3 Results and Discussion  
### Development of the Qualitative Composition of the Biopreparation  
Microorganisms most often transform NSAIDs into their hydroxyl derivatives, and in this form, they get from biological sewage treatment plants to the environment. Few bacteria and fungi break down these drugs into intermediates of basal metabolism [1; 2; 17; 29; 30]. One of the best-known mechanisms of drug degradation is the degradation of paracetamol. It is most often transformed into such critical metabolites as 4-aminophenol and hydroquinone. The degradation of these intermediates limits this drug's degradation rate [31; 32]. Moreover, many papers concern the decomposition of ibuprofen, the first step of which is usually hydroxylation of the aromatic ring or the side chain carbon. Complete degradation proceeds with the aromatic ring cleavage, most often carried out by enzymes belonging to the cleaving dioxygenases [33; 34; 35]. Diclofenac and naproxen are much more difficult to decompose. There are few reports on the degradation of naproxen, and the critical step in its decomposition is demethylation to desmethylnroxen. Naproxen is often degraded by pathways typical for naphthalene derivatives, where salicate 1,2-dioxygenase, responsible for the cleavage of the aromatic ring, plays a unique role [3; 36]. Hydroxylation is also the first step in the transformation of diclofenac. In the following steps, the amino bond between the rings is hydrolyzed. Monocyclic intermediates can be degraded via various pathways to the final products, which are central metabolism intermediates [1; 2]. The bacteria in which the complete decomposition of paracetamol has been described include the _Pseudomonas moorei_ KB4 strain isolated from the activated sludge from the wastewater treatment plant Klimzowiec (Chorzow, Poland), which is also characterized by the ability to degrade diclofenac [24; 37]. In turn, the _Bacillus thuringiensis_ B1(2015b) strain, isolated from the soil of the chemical factory Organika-Azot in Jaworzno (Poland), belongs to the bacteria that break down ibuprofen and naproxen [38; 39]. These strains were used to construct a preparation composed of immobilized bacteria on a plant sponge from _Loofha cylindrica._ In addition, the preparation was enriched with the _Stenotrophomonas maltophilia_ KB2 strain, which can degrade naproxen and a wide range of aromatic compounds due to the rich enzyme system [25; 40]. The second tested strain is _Planococcus_ sp. S5, showing the ability to decompose phenolic compounds and naproxen [21; 41]. Both strains were isolated from the activated sludge of a sewage treatment plant in Bytom Miechowice (Poland) [25; 41]. In the conducted research, it was essential to determine the optimal species composition of the preparation. Three systems were selected for the study: V1--containing strains B1(2015b), KB4 and KB2, V2--including strains B1(2015b), KB4 and S5 and V3--containing all four tested strains. In earlier studies [11], the KB2 strain was shown to be antagonistic to the KB4 strain. However, the obtained results indicate that the immobilization of the KB2 strain abolishes this effect, as no significant differences were observed in any of the tested systems (Figures 1-3). Figure 1: Degradation of paracetamol (**A**) and ibuprofen (**B**) in cultures containing systems of bacterial strains V1, V2, and V3. Figure 2: Degradation of paracetamol (**A**); ibuprofen (**B**); naproxen (**C**); and diclofenac (**D**) in the presence of a mixture of drugs in cultures containing systems of V1, V2, and V3 bacterial strains. In the first stage of the research, the distribution of 250 ug/L of paracetamol and ibuprofen by each tested system was checked. It was shown that the V1 and V3 systems degraded paracetamol within 18 h, while the degradation of this drug by the V2 system took up to 24 h (Figure 1A). However, no significant differences were observed in the degradation of ibuprofen by all the tested systems, which occurred within 28 h (Figure 1B).