## 2 Results and Discussion
### Biochemical Characteristics and Cellular Fatty Acid Composition of the ZCR6 Strain  
The biochemical characteristics revealed that _P. qingdaonensis_ ZCR6 was positive for oxidase, catalase, and arginine dihydrolase, and was able to produce pyoverdine. In turn, it  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{PCF Mechanisms} & \multicolumn{3}{c}{**Plant**} & \multicolumn{3}{c}{**Surface-Active Proportional**} \\  & & & & & & & & & & & & & \\ \hline \multirow{2}{*}{**ACCD***} & \multirow{2}{*}{**LAA***} & \multirow{2}{*}{**C\({}_{99}\)/O\({}_{2}\)**\(\sigma\)**} & \multirow{2}{*}{**Slatformphan**} & \multirow{2}{*}{**BCN***} & \multirow{2}{*}{**NH\({}_{3}\)**\(\sigma\)**} & \multirow{2}{*}{**CMC***} & \multirow{2}{*}{**Suffix**} & \multirow{2}{*}{**Timeon**} & \multirow{2}{*}{**BCN***} & \multirow{2}{*}{**Suffix**} & \multirow{2}{*}{**BCN***} \\  & & & & & & & & & & & & & \\ \hline
206.73 \(\pm\) 1.27 & 3.59 \(\pm\) 0.11 & 6.5 \(\pm\) 0.53 & - & - & + & + & 46.1 \(\pm\) 0.55 & 4.0 \(\pm\) 0.2 & 25.71 \(\pm\) 0.57 & 71.0 \(\pm\) 1.40 & 14.71 \(\pm\) 0.29 \\ \hline \hline \end{tabular}  
* \({}^{\text{a}}\)ACCD activity (nmol a-ketobutyrate mg\({}^{-1}\) h\({}^{-1}\)); \({}^{\text{b}}\) (AA mL-1 of medium); \({}^{\text{c}}\) the halo diameter (mm) calculated by subtracting the colony diameter from the total halo size; \({}^{\text{d}}\)-8 + positive; \({}^{\text{e}}\) – negative; \({}^{\text{h}}\) (mN m\({}^{-1}\);\({}^{\text{i}}\) (mm); \({}^{\text{j}}\) (\%); \({}^{\text{k}}\) H–\(\pi\)-hexadecane; \({}^{\text{i}}\) X–\(p\)-xylene; \({}^{\text{m}}\) D–diesel oil.  
\end{table}
Table 1: The activity of the plant-growth-promoting mechanisms and surface-active abilities of the ZCR6 strain.  
Figure 1: Maximum-likelihood-based phylogeny resulting from the concatenated 16S rRNA, _gyrB_, and _rpoD_ sequences, representing the relative position of the ZCR6 strain among other _Pseudomonas_. All positions containing gaps or missing data were eliminated. The final dataset contained 2563 positions. Accession numbers of sequences used in this study are listed in Supplementary Table S1. Bootstrap values are represented at the branching points. The bar represents 0.05 substitutions per site. Each strain is given an ANI value relative to the sequences belonging to the ZCR6 strain; \({}^{\text{e}}\) strain JJ\({}^{\text{T}}\) with the highest ANI value.  
was negative for dehydrogenase, urease, nitrate reductase, and gelatinase, and was unable to hydrolyze starch and produce pyocyanin. The obtained results were consistent with those obtained in [20] for the _P. qingdaonensis_ strain \(\mathrm{JJ^{T}}\), except for its starch hydrolysis ability and the production of pyoverdine; however, these may be due to natural variability between strains belonging to the same species.  
The cellular fatty acid composition of the ZCR6 strain showed a high percentage of C16:0 (30.98%), C16:1\(\omega\)7c/C16:1\(\omega\)6c (26.35%), C18:1\(\omega\)7c/C18:1\(\omega\)6c (15.44%), and C17:0 cyclo (10.22%) fatty acids. Additionally, the hydroxylated fatty acids C12:0 2 OH, C12:0 3 OH, and C10:0 3 OH were detected, and their abundance was in the range of 3.34-4.63%. Moreover, C12:0 and C19:0 cyclo \(\omega\)8c fatty acids were present; however, their abundance was low, 2.22% and \(<1\%\), respectively (Table 2). These results differed from the profile obtained for the \(\mathrm{JJ^{T}}\) strain, which was dominated by C17:0 cyclo (24%) and C16:0 (21.4%), while C16:1\(\omega\)7c/C16:1\(\omega\)6c and C18:1\(\omega\)7c/C18:1\(\omega\)6c fatty acids constituted only 11.5% and 10.5% of the total fatty acids, respectively [20]. However, [PERSON] et al. [20] used a three-day-old culture instead of a 24-h-old culture, as is required and recommended in the MIDI-MIS method. To compare our results with \(\mathrm{JJ^{T}}\) strain fatty acid methyl esters (FAMEs), analysis of three-day-old ZCR6 culture was performed. The obtained results showed a high similarity of both profiles.