Organizing co mmittee

particles with paramagnetic properties were formed. The 
particles were washed with 50% ethanol. To synthesize the SiO
2
layer on the surface of the 
magnetic particles, TEOS (tetraethylorthosilicate) was used for the Stöber reaction. After the 
reaction, the paramagnetic particles were washed three times with 50% ethanol, and the Stöber 
reaction was carried out again.
The analysis of the sorption properties of the synthesized paramagnetic sorbent was 
carried out by isolating DNA from the 
E. coli
cell culture using solutions of the 
SOREX-DNA commercial kit (ICPS, Uzbekistan) according to the instructions. The 
isolated bacterial DNA was analyzed by gel electrophoresis in 0.7% agarose gel. 
As seen in fig. 1, in samples 1–4, a high-molecular fragment of genomic DNA is 
observed, while in samples 5 and 6 this DNA fragment is absent. 
Thus, it has been established that the thickness of the SiO
2
surface layer affects the 
sorption properties of the paramagnetic sorbent. 
 
Figure 1. Gel electrophoresis of 
isolated 
E. coli
genomic DNA
 
1,2 – genomic DNA isolated using 
Silicagel 5/40 sorbent 
3,4 – genomic DNA isolated using a 
paramagnetic sorbent with a 3-fold 
coating of SiO
2 
5,6 - genomic DNA 
isolated using paramagnetic sorbent 
with 1x SiO
2
coating 

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Poster presentation 
190 
SCREENING FOR PHOSPHATE-SOLUBILIZING WHEAT 
RHIZOBACTERIA (Triticum aestivum) 
 
G.Х. Кadirova, М.S. Sadullayeva, Т.S. Хusanov, Т.E. Shonaxunov
 
Institute of Microbiology of the Academy of Sciences, Tashkent, Uzbekistan;
e-mail: [e-mail]
 
Soil fertility and sustainable agriculture are crucial for ensuring global food security. 
The majority of soils with high sorption capacity have scarce phosphorus (P) resources 
that fall far short of what agriculture needs, it is not enough agricultural fertility and 
productivity. Agricultural soils typically have a phosphorus content of 0.05%, of which 
only 0.1% is accessible to plants. Biological phosphate solubilization, which is carried 
out by soil microorganisms and facilitates the conversion of sparingly soluble 
phosphorus compounds into forms accessible to higher plants, is one of the potential 
approaches for increasing the phosphorus nutrition of agricultural crops. 
The objective of this study is to identify and screen wheat (
Triticum aestivum
L.) 
phosphate-solubilizing rhizobacteria (FSR) for the capacity to produce acids. 
More than 50 isolates (pure cultures) of FSR were found in the root zone of wheat 
(
Triticum aestivum
L.), which was grown in the Tashkent and Kashkadarya regions of 
the Republic in the cultivars "Asr," "Yaksart," and "Thunder." The dynamics of growth 
and development were demonstrated by 20 of the isolates isolated in pure culture, who 
were able to dissolve tricalcium phosphate on the Pikovsky nutritional medium with an 
indicator, generating a transparent zone. It has been determined that the 
Acinebacter, 
Clostridium, Enterobacter, Pseudomonas, Bacillus, Exiguobacterium
, and 
Serratia
genera contain the most active FSR strains
. 
It is known that one of the main 
mechanisms recognized as responsible for the release of available forms of phosphorus 
by plants in the soil is the production of organic acids and an increase in the activity of 
acid phosphatases. Therefore, the next stage of the research was to determine the 
formation of total titratable acids by active FSR. It has been established that all studied 
FSR form organic acids, but the most active acid-forming cultures are 
Acinebacter pittii
1K, 
Bacillus cereus
11K, 
Acinebacter pittii
2K, 
Enterobacter cloacae
9K, 
Exiguobacterium 
sp.12K, 
B. cereus
16K, 
Serratia marcescens
21K, 
E. cloacae
FA, 
Pseudomonas aeruginosa
23A, 
P. aeruginosa
28A, 
E. cloacae
34A and 
B. subtilis
35A. 
It should be noted that in the most active PS strains 
S. marcescens
21K and 
P. 
aeruginosa
23A, the total amount of titratable acids for 15 days remains at the level of 
28.4 mg/ml to 36.0 mg/ml and from 14.6 to 32.4 mg/ml. Today, improving phosphate 
bioavailability for crop productivity is the main objective for sustainable agricultural 
development. Isolated local strains of FSR are extremely effective as biofertilizers in 
this situation because they boost phosphorus' bioavailability to plants, support 
sustainable agriculture, and enhance soil fertility and crop yields.