Phosphate solubilizing microorganisms (PSMs) in soil have been shown to reduce mineral phosphate fertilizer supplementation and promote plant growth. Nevertheless, only several P-solubilizing microorganisms capable of solubilizing both organic and mineral sources of soil phosphorus have been identified up to now. The aim of this study was to evaluate the inorganic soil phosphate solubilizing activity of phytate-hydrolyzing Pantoea brenneri soil isolates. We showed that the strains efficiently solubilize a variety of inorganic phosphates. We optimized the media composition and culturing conditions to improve the solubilization efficiency of the strains and investigated the mechanisms of their phosphate solubilization. Through HPLC analysis, it was determined that P. brenneri produce oxalic, malic, formic, malonic, lactic, maleic, acetic, and citric acids as well as acid and alkaline phosphatases while growing on insoluble phosphate sources. Finally, we analyzed the influence of P. brenneri strains with multiple PGP-treats on plant growth in greenhouse experiments and showed their ability to promote growth of potato.

The objective of this study was to assess the effect of AgpP-P phytase supplementation on productivity, nutrient availability, zoo-sanitary assessment of meat and serum biochemical parameters of Hubbard broilers. A total of 180 one-day-old Hubbard broiler chickens were randomly divided into 2 groups (control and experimental) with 3 replicates and 30 broilers per replicate. In the experimental group, the diet was supplemented with phytase preparation at 1000 FTU/kg. Results showed that phytase supplementation increased body weight and absolute weight gain in Hubbard broilers, while reducing the total amount of feed consumed by birds (P < 0.05). Phytase improved the availability and absorption of organic nutrients, calcium and phosphorus. However, no differences were observed for N absorption (P<0.05). Phytase supplementation increased Ca and P contents, total protein level and alanine aminotransferase activity, and reduced urea level, aspartate aminotransferase and alkaline phosphatase activities in serum (P < 0.05). The meat of phytase-fed broilers meets Russian State Standards for fresh, good-quality meat based on organoleptic and physico-chemical characteristics. In conclusion, it was established that the addition of phytase at 1000 FTU/kg to the diet for broilers enhances the digestibility of the organic and mineral components of the feed ration, increases body weight in birds and reduces the amount of feed consumed.

The studies were conducted to determine the role of strains of soil bacteria Pantoea brenneri in increasing the bioavailability of soil phosphorus and to assess the biotechnological potential of the strains for use as biofertilizers. Soil microcosms were created in four variants: inoculated non-sterile soil (30 g + 5 ml of P. brenneri suspension, 1.5×108 CFU/ml); control with non-sterile soil (30 g + 5 ml of 0.9% NaCl); Inoculated sterile soil (30 g + 5 ml P. brenneri suspension, 1.5×108 CFU/ml); control with sterile soil (30 g + 5 ml 0.9% NaCl). Microcosms were incubated for 15 days, samples were taken at the beginning and end of incubation. Phosphate mobilization of P. brenneri strains in soil is confirmed by an increase in the expression level of gdh (glucose dehydrogenase) and pho (phosphatase) genes, the products of which are involved in the solubilization and mineralization of hard-to-reach phosphorus compounds. Expression of the target genes in sterile soil was higher than in non-sterile soil, depending on the incubation time and strain used: for the gdh gene - on average by 1.2...1.9 times, for the pho gene - on average by 1.3...1.7 times. The introduction of the strain suspension into the soil contributed to an increase in the number of bioavailable forms of phosphorus in sterile soil by an average of 22...27%, in non-sterile soil - by 15...18%. P. brenneri strains remained viable in the soil throughout the experiment, which characterizes their ability to compete with native soil microflora. On the 5th day of incubation, a 6-8-fold increase in the number of CFU/g of soil was noted, compared with the initial point (day 0), and on the 15th day, the value of this indicator exceeded the initial value by an average of 3...4 times.

Background The major storage form of phosphorus in plant-derived feed is presents by insoluble phytates and not digested by animals. Microbial enzymes phytases are able to hydrolyze phytates and are widely used as feed additives in animal nutrition to improving the utilization of phytate-phosphorus in diets and reducing manure phosphorus excretion to the environment. However, no single phytase can perform effectively under various conditions of digestive systems and dietary compositions. That's why there is a constant search and development of new effective feed phytases preparations. The objective of this study was to study the effect of AgpP-P phytase supplementation on productivity, nutrient availability, veterinary-sanitary assessment of meat and serum biochemical parameters of Hubboard broilers. Results Results showed that phytase supplementation increased body weight and absolute weigh gain in broilers, while reducing the total amount of feed consumed by birds (P < 0.05). Phytase improved the availability and absorption of organic nutrients, calcium (Ca) and phosphorus (P). However, no differences were observed for nitrogen (N) (P < 0.05). Phytase supplementation increased Ca and P contents, total protein (TP) level and alanine aminotransferase (ALT) activity, and reduced urea level, aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities in serum, respectively (P < 0.05). The meat of phytase-fed broilers meets Russian State Standards (GOST) for fresh good-quality meat based on organoleptic, physicochemical and bacterioscopic characteristics. Conclusions The results of present study demonstrated that addition of AgpP-P phytase to the diet of broiler chickens has a positive effect on the nutrient availability and productivity of birds, while reducing the total amount of feed consumed by chickens. Biochemical parameters in serum remained within the physiological norm. The meat of phytase-fed broilers met the Russian State Standards (GOST) for fresh good-quality meat. Thus, it is shown that AgpP-P phytase has the potential for use as a feed additive in poultry farming.