# Effect of Pseudomonas Fluorescens on Isofetamid Dissipation and Soil Microbial Activity
## 4 Discussion  
### Effect of P. fluorescens on Soil Properties and Isofetamide Dissipation  
According to the literature, _P. fluorescens_ as PGPR is a biofertilizer and biocontrol agent that by interacting with the root zone of plants, stimulates the absorption of nutrients by plants and improves soil fertility. _P. fluorescens_ has the ability to solubilize phosphorus, which means that it transforms forms that are unavailable into forms that are available to plants [17; 33; 34]. In addition, the _Pseudomonas_ sp. is capable of nitrogen fixation and the conversion of soil ammonium, thanks to which it makes the pool of nitrogen available for plants. In our study, a higher content of TN and TP was observed in the IS+P variant than in the control and IS samples. In addition, higher TOC contents were found in IS+P compared to the other research variants. Some researchers showed that with the introduction of _Pseudomonas_ sp. inoculum, the soil pH decreased due to the production of various acids [35]. A similar relationship was not detected in our study, which could be due to the presence of isofetamid and its influence on the processes occurring in the soil. [PERSON] et al. [36] reported that _P. fluorescens_ can inhibit soil acidification, but the nature of changes depends on many factors, including the physicochemical properties of the soil. The literature data indicate that _Pseudomonas_ sp. has the ability to degrade pollutants, including pesticides, which means that they may be potential candidates in the bioremediation process [18]. [PERSON] et al. [37] showed that _P. fluorescens_ isolated from soil has the ability to degrade endosulfan at an initial concentration of 350.24 \(\mu\)g/L within 12 days in a batch experiment, and, after 18 days, complete degradation of the pesticide was achieved. [PERSON] et al. [38] reported that the _P. fluorescens_ strain c50 effectively removed atrazine within 30 days. Our study demonstrated that the concentration of isofetamid was lower in the variant with _P. fluorescens_ than in the variant with IS alone throughout the entire  
Figure 5: (**A**) Biplot showing the relationships between the study variables, including the research variants. (**B**) Pearson correlation matrix presenting relationships between studied variables. study period, which indicates the potential of the tested strain to degrade isofetamid. The reason for this may be the effect of _P. fluorescens_, which, during its development, can use the pesticide as a source of carbon and energy (cometabolism), which may result in a decrease in the pesticide content [39]. The dissipation of isofetamid depends on various factors including soil type, pH, temperature, moisture, etc. [7]. It should be emphasized that both variants were in the same experimental conditions. Our studies have shown that the disappearance of isofetamid from the IS and IS+P variants had a similar character/trend, but a higher concentration of isofetamid was noted in IS. A similar trend may result from the fact that in the IS soil (like in IS+P), there were also other microorganisms that showed activity in IS decomposition and reduced its content, and, in both cases, the same factors intensifying isofetamid decomposition were at work, but, in the IS+P variant, this decomposition was more intense. This can be explained by a significant negative correlation between the isofetamid concentration and the number of bacteria, where the number of bacterial gene copies was similar or higher than in the control. Additionally, it was found that a significant reduction in the content of isofetamid was observed between 7 and 14 days after application. According to the PPDB document [8], the biodegradability of isofetamid in a typical aerobic soil is 37.1 days. The decomposition of pesticides in soil depends on many factors, including pH, organic matter content, and the composition and activity of microorganisms. Studies conducted by [PERSON] et al.