Organic Phosphorus Sources Research Articles

Different elemental stoichiometries of Fe‐limited Trichodesmium when grown under inorganic and organic phosphorus sources

AbstractTrichodesmium spp. is a colonial diazotrophic cyanobacterium found in the oligotrophic (sub)tropical oceans, where its distribution is strongly regulated by the availability of phosphorus and iron. The bulk carbon : nitrogen : phosphorus elemental composition of phytoplankton has previously been shown to depart from classical “Redfield” values under nutrient‐limitation conditions. We hypothesized that the abundance of intracellular metabolites and the extended Redfield ratios of Trichodesmium, including a range of trace elements, are variable in response to conditions of phosphorus and iron limitation that are found in the ocean. To test this, we grew Trichodesmium under trace metal–controlled conditions, where phosphorus was supplied as either dissolved inorganic phosphorus (DIP) or dissolved organic phosphorus (DOP) from iron depleted to elevated levels. We found that the steady‐state extended Redfield ratios of Trichodesmium under the iron‐depleted condition was (C106N15.82P0.62)1000Fe2.26Zn2.37Mn1.68Cu0.68Ni0.31Mo0.42Co0.03 for the DIP treatment where Trichodesmium was under iron limitation, and (C106N13.89P0.49)1000Fe3.38Zn2.51Mn0.97Cu0.52Ni0.42Mo0.33Co0.03 for the DOP treatment where Trichodesmium was under iron–phosphorus co‐limitation. Mean steady‐state cellular iron : carbon in the DIP treatment (iron limited) was only 50% of that in the control treatment, while zinc : carbon was elevated twofold. The average extended Redfield ratios following recovery from iron limitation was (C106N16.8P0.7)1000Fe4.41Zn1.44Mn1Cu0.52Ni0.19Mo0.3Co0.03 for the DIP and (C106N15.9P0.73)1000Fe7.36Zn2.24Mn1.08Cu0.71Ni0.63Mo0.38Co0.02 for the DOP treatment. No significant changes were observed in the carbon‐normalized abundance of targeted metabolites produced by Trichodesmium, under the different treatments. These results suggest Trichodesmium employs different strategies to cope with iron/phosphorus limitation, which is reflected in its extended Redfield ratios.

Effects of the integrated use of organic and inorganic phosphorus sources in micro-doses on the yield and profitability of cowpea (Vigna unguiculata L. Walp) Cultivation

An experiment was conducted in the field to evaluate the effect of phosphorus fertilization in microdose using organic and mineral fertilizers on the yield and profitability of cowpea cultivation. To achieve this, a balanced application of NPK and granular compost was provided to supply the same amount of phosphorus to the cowpea. Three treatments were compared in a split-plot design with three replications, where the treatments were in large plots and the cowpea varieties, numbering four (4), were in small plots. The three treatments are as follows: (i) T0 control treatment without fertilizer application, (ii) T1 application of two grams of NPK per hole, and (iii) T2 application of 9.375 grams of granular compost per hole. The results show a significant difference in yield parameters between treatments (pod yield, grain yield, and straw yield). The mean comparison test revealed that the control treatment and NPK are quite similar for these parameters. Thus, with compost, an increase of 69.17% in grain yield, 55.47% in pod yield, and 41.67% in straw yield was noted compared to the control. The VCR (value-cost ratio) and gross income were significantly improved by compost. The application of organic or mineral fertilizers for cowpea cultivation is profitable due to relatively high VCRs: 3.34 for NPK and 6.79 for compost. Therefore, the use of compost for cowpea cultivation proves to be economically more profitable, as it yields higher returns.

Synthesis of LiFePO4 using adenosine triphosphate as a new organic phosphorus source and its solvothermal reaction process

LiFePO4 is prepared by hydrothermal method using phosphoric acid (named as LFP-a) or adenosine triphosphate (LFP-b) as phosphoric sources, respectively. The effects of two phosphorus sources on crystal structure, particle morphology and electrochemical properties of the materials are investigated. Meanwhile, the mechanism of adenosine triphosphate as phosphoric source to synthesis LiFePO4 is proposed. The results show that the phosphorus source has significant influence on the synthesized materials. Compared with LFP-a, LFP-b material has higher crystallinity, better particle uniformity and dispersion. This is the result of the slow release of Li3PO4 in the hydrothermal process of the ATP-dominated precursor solution, and the subsequent reaction is relatively ordered, resulting in excellent electrochemical performance: the reversible capacity at 1 C is 148.24 mAh g−1, 137.01 mAh g−1 after 100 cycles, and the capacity retention rate is 92.4 %. This work provides a reference for the preparation of high-performance LiFePO4 from organophosphorus sources.

Preparation and application of rosin@apatite hybrid material with new natural surfactants based on in-situ reaction by sol-gel method

Due to the combination of organic and inorganic advantages, organic@inorganic hybrid materials have important applications in drug-loading, water-treatment and other fields. Rosin@apatite (AP) hybrid materials with various morphologies were designed and obtained by in situ reaction using two novel rosin-based phosphoester surfactants as organic phosphorus sources. The hybrid materials combined multi-ring, multi-electron groups of natural rosin diterpene and strong physical adsorption properties of apatite. Block and sheet rosin@AP hybrid materials were prepared by sol–gel method with mild reaction conditions. The materials have excellent adsorption capacity of phenol (9.2 mg g−1) and loading capacity (492 mg g−1) of adriamycin (DOX) induced by π–π stacking interaction with rosin bases. The content of rosin based organic materials in hybrid materials is as high as 47.5% by thermogravimetric analysis. The formation mechanism of hybrid materials was speculated in detail.

Efficient activation of persulfate for tetracycline hydrochloride degradation by biochar prepared from corn stover doped with organic phosphorus sources

Proposed to prepare phosphorus-doped biochar catalyst materials by impregnation pyrolysis method using corn stover and different phosphorus source precursors as raw materials, and the batch-wise research revealed that the phosphorus source precursor, the doping ratio, and the pyrolysis temperature had a significant influence on the biochar properties. The biochar material Pb-C-4–600 prepared with (C4H9)3PO4 as phosphorus source precursor, 1:4 doping ratio, and pyrolysis temperature of 600 ℃ had an ID/IG = 0.914, pore size of 4.91 nm, and specific surface area of 173.9845 m²/g, which was 93.4 times higher than that of the pure biochar. The removal rate of TCH reached 99.77 % in 30 min under the reaction conditions of PMS concentration of 2 g/L, Pb-C-4–600 dosage of 1 g/L, and pH 3. Comparing the efficacy of Pb-C-4–600 and different catalysts for the degradation of TCH by activated PMS under the same reaction conditions, the degradation reaction rate of Pb-C-4–600 was 0.17663 min−1, which was 1.48 times higher than that of N-bio, 1.67 times higher than that of S-bio, and 2.64 times higher than that of B-bio, which further demonstrating the advantages of Pb-C-4–600 in similar composites. The oxidative degradation performance of other typical organic pollutants (BPA, phenol, AO7) was also good. The prominent reactive oxidizing radical in the system of Pb-C-4–600/PMS was SO4·−, and the system could adapt to a wide pH range.

Parsley production using organic sources of phosphorus

Parsley is a condiment produced mainly by small producers, often in the organic system. Organic fertilizers make nutrients slowly available to plants when compared to inorganic fertilizers, an important quality for phosphorus (P), which is a nutrient that tends to fixate and adsorption. Thus, the objective of this work was to evaluate the production of parsley with the use of organic sources of phosphorus in different proportions. Fourteen treatments were evaluated, resulting from the factorial 6 x 2 + 2: six proportions of two phosphate fertilizers (thermophosphate Yoorin® (TY) and bone meal (BM)), two doses (recommended (180 kg.ha-1 of P2O5, and double this) + two controls (without phosphate fertilizer; and with inorganic triple superphosphate fertilizer (recommended dose)). The proportions were: 100% P with TY; 80% P with TY + 20% with BM; 60% P with TY + 40% with BM; 40% P with TY + 60% with BM; 20% P with TY + 80% with BM; 100% P with BM. Shoot height, number of leaves, fresh and dry weight of leaves in two harvests and the total of these two harvests were evaluated. No significant differences were obtained in the two harvests. The lack of effect to phosphate fertilization may be related to the high initial P content in the soil (123 mg.dm-3), which shows that in this case, fertilization with this nutrient is not necessary to produce parsley, despite the official recommendation to fertilize with phosphorus in a soil with a high P content.

Broad-spectrum pH functional chitosan-phosphatase beads for the generation of plant-available phosphorus: utilizing the insoluble P pool.

Utilization of organic phosphates and insoluble phosphates for the gradual generation of plant-available phosphorus (P) is the only sustainable solution for P fertilization. Enzymatic conversions are one of the best sustainable routes for releasing P to soil. Phosphatase enzyme aids in solubilizing organic and insoluble phosphates to plant-available P. We herein report the preparation of highly functional chitosan beads co-immobilized with acid phosphatase and alkaline phosphatase enzymes via a glutaraldehyde linkage. The dual enzyme co-immobilized chitosan beads were characterized using Fourier-transform infrared (FTIR), thermogravimetric (TGA), and scanning electron microscopy-energy dispersive x-ray (SEM-EDX) analyses to confirm the immobilization. The co-immobilized system was found to be active for a broader pH range of ∼4-10 than the individually bound enzymes and mixed soluble enzymes. The bound matrix exhibited pH optima at 6 and 9, respectively, for acid and alkaline phosphatase and a temperature optimum at 50°C. The phosphate-solubilizing abilities of the chitosan-enzyme derivatives were examined using insoluble tri-calcium phosphate (TCP) for wide pH conditions of 5.5, 7, and 8.5 up to 25 days. The liberation of phosphate was highest (27.20mg/mL) at pH 5.5 after the defined period. The residual soil phosphatase activity was also monitored after 7days of incubation with CBE for three different soils of pH ∼5.5, 7, and 8.5. The residual phosphatase activity increased for all the soils after applying the CBE. The germination index of the Oryza sativa (rice) plant was studied using different pH buffer media upon the application of the CBE in the presence of tri-calcium phosphate as a phosphate source. Overall, the dual-enzyme co-immobilized chitosan beads were highly effective over a wide pH range for generating plant-available phosphates from insoluble phosphates. The chitosan-enzyme derivative holds the potential to be used for sustainable phosphorus fertilization with different insoluble and organic phosphorus sources.

Microbial strategies for phosphorus acquisition in rice paddies under contrasting water regimes: Multiple source tracing by 32P and 33P

Microbial acquisition and utilization of organic and mineral phosphorus (P) sources in paddy soils are strongly dependent on redox environment and remain the key to understand P turnover and allocation for cell compound synthesis. Using double 32/33P labeling, we traced the P from three sources in a P-limited paddy soil: ferric iron-bound phosphate (Fe-P), wheat straw P (Straw-P), and soil P (Soil-P) in microbial biomass P (MBP) and phospholipids (Phospholipid-P) of individual microbial groups depending on water regimes: (i) continuous flooding or (ii) alternate wetting and drying.32/33P labeling combined with phospholipid fatty acid analysis allowed to trace P utilization by functional microbial groups. Microbial P nutrition was mainly covered by Soil-P, whereas microorganisms preferred to take up P from mineralized Straw-P than from Fe-P dissolution. The main Straw-P mobilizing agents were Actinobacteria under alternating wetting and drying and other Gram-positive bacteria under continuous flooding. Actinobacteria and arbuscular mycorrhiza increased P incorporation into cell membranes by 1.4–5.8 times under alternate wetting and drying compared to continuous flooding. The Fe-P contribution to MBP was 4–5 times larger in bulk than in rooted soil because (i) rice roots outcompeted microorganisms for P uptake from Fe-P and (ii) rhizodeposits stimulated microbial activity, e.g. phosphomonoesterase production and Straw-P mineralization. Higher phosphomonoesterase activities during slow soil drying compensated for the decreased reductive dissolution of Fe-P. Concluding, microbial P acquisition strategies depend on (i) Soil-P, especially organic P, availability, (ii) the activity of phosphomonoesterases produced by microorganisms and roots, and (iii) P sources – all of which depend on the redox conditions. Maximizing legacy P utilization in the soil as a function of the water regime is one potential way to reduce competition between roots and microbes for P in rice cultivation.

Mineralization of phosphorus as influenced by different organic and inorganic sources of phosphorus in calcareous soil

Mineralization of phosphorus as influenced by different organic and inorganic sources of phosphorus in calcareous soil

Different organic manures and inorganic sources of phosphorus as influenced on nutrient availability in calcareous soil

Different organic manures and inorganic sources of phosphorus as influenced on nutrient availability in calcareous soil

Ciclagem de Nitrogênio, Fósforo e Potássio em Ecossistemas de Pastagem

Abstract Inadequate management practices are the main factors that can cause pasture degradation, and one of the key factors is to understand the nutrient cycling in pasture ecosystems. This review aimed to describe the cycling processes of important nutrients in pasture ecosystems (nitrogen, phosphorus, and potassium), analyzing the interactions of soil-plant-animal components. The use of forage legume species intercropped with grasses is a strategy to increase the nitrogen content in the soil, minimizing costs with nitrogen fertilization in pastures. Manure and plant residues are great organic sources of phosphorus and potassium but are also fundamental for supplying microminerals. Nitrogen losses in pastures are mainly caused by leaching, runoff, and volatilization. The addition of phosphorus to the soil must be performed carefully, as there is an increase in phosphorus losses with increasing accumulation in the soil. Phosphorus is often returned to the soil far from where it was used, so the stock transfer represents a loss in pasture ecosystems that can account for approximately 5% of the inputs of phosphate fertilizers. Potassium losses mostly occur by leaching and runoff. Improving management practices is essential for balanced nutrient cycling in pasture ecosystems.

Multi-omics analysis reveals the roles of purple acid phosphatases in organic phosphorus utilization by the tropical legume Stylosanthes guianensis.

Stylo (Stylosanthes guianensis) is a tropical legume known for its exceptional tolerance to low phosphate (Pi), a trait believed to be linked to its high acid phosphatase (APase) activity. Previous studies have observed genotypic variations in APase activity in stylo; however, the gene encoding the crucial APase responsible for this variation remains unidentified. In this study, transcriptomic and proteomic analyses were employed to identify eight Pi starvation-inducible (PSI) APases belonging to the purple APase (PAP) family in the roots of stylo and seven in the leaves. Among these PSI-PAPs, SgPAP7 exhibited a significantly positive correlation in its expression levels with the activities of both internal APase and root-associated APase across 20 stylo genotypes under low-Pi conditions. Furthermore, the recombinant SgPAP7 displayed high catalytic activity toward adenosine 5'-diphosphate (ADP) and phosphoenolpyruvate (PEP) in vitro. Overexpression (OE) of SgPAP7 in Arabidopsis facilitated exogenous organic phosphorus utilization. Moreover, SgPAP7 OE lines showed lower shoot ADP and PEP levels than the wild type, implying that SgPAP7 is involved in the catabolism and recycling of endogenous ADP and PEP, which could be beneficial for plant growth in low-Pi soils. In conclusion, SgPAP7 is a key gene with a major role in stylo adaptation to low-Pi conditions by facilitating the utilization of both exogenous and endogenous organic phosphorus sources. It may also function as a PEP phosphatase involved in a glycolytic bypass pathway that minimizes the need for adenylates and Pi. Thus, SgPAP7 could be a promising target for improving tolerance of crops to low-Pi availability.

Improvement in Wheat Productivity with Integrated Management of Beneficial Microbes along with Organic and Inorganic Phosphorus Sources

Phosphorus (P) unavailability in agricultural soils is a primary cause of the poor development and yield of field crops in arid and semiarid regions. The primary goal of this research project was to investigate the influence of integrated management of beneficial microbes or biofertilizers (BF), organic P-fertilizers, and inorganic P-fertilizers on wheat productivity in a wheat–maize cropping system. Field experiments were carried out during the two consecutive seasons of 2020/2021 (Y1) and 2021/2022 (Y2) according to the two-factorial randomized complete block design with three replications. Factor one consisted of twenty-one treatments of organic and inorganic P-fertilizer combinations, while factor two consisted of two different BF (PSB and Bioaab). One overall control where no P or BF was applied was also included in each replication for comparison. The experiment consisted of six treatments of sole P sources (sheep manure (SM), cattle manure (CM), legume residues (LR), non-legume residues (NLR), single super phosphate (SSP) and rock phosphate (RP)), each applied at a rate of 90 kg P ha−1. Different combinations of organic and inorganic P sources (giving 15 treatments) were applied at a rate of 50% P from each source (i.e., 45 kg P ha−1 applied from different sources in combination). The results revealed that the combined application of SSP+SM produced a significantly higher number of grains spike−1 (23.9%), spikes m−2 (4.5%), and grain yield (40.9%) over the control. Application of PSB produced the maximum number of grains spike−1 (23.9%), spikes m−2 (4.5%), thousand-grain weight (8.3%), grain yield (40.9%), and biological yield (17%) in the wheat crop as compared to Bioaab. It was concluded from the two-year study that integrated use of organic P-fertilizers (animal manures) plus inorganic P-fertilizer (SSP) along with PSB ranked first in terms of higher wheat productivity in a wheat–maize cropping system.

Phosphate Solubilization and Plant Growth Promotion by Pantoea brenneri Soil Isolates.

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.

High-throughput shoot phenotyping reveals temporal growth responses to nitrogen and inorganic and organic phosphorus sources in tomato.

The application of nitrogen (N) and phosphorus (P) fertilizers to soils is required to maintain crop yields, so the sufficient and timely delivery of nutrients to match crop demand is important in fertilizer management. We quantified temporal growth responses of tomato plants with different rates of N and P application using high-throughput shoot phenotyping. The tomato plants were grown in soil that had organic, inorganic or a combination of sources of P incorporated. Additional N was added to each pot at low and high rates, 13 days after planting. At the same rate of total P application, the inorganic P source resulted in greater shoot growth at the early time points. Later on, the plants supplied with organic or mixed P sources grew faster than those that received the inorganic P source, resulting in comparable shoot biomass in all treatments at the time of destructive harvest. The shoot phenotyping data demonstrated that readily available soil P was important for early tomato growth while available N was more important in later stages of vegetative growth. These results suggest that a fertilizer formulation of combined inorganic and organic P sources may be able to sustain rapid and great shoot growth in tomato plants, while also reducing additional N input.

Effect of organic and inorganic sources of phosphorus for enhancing productivity and phosphorus use efficiency in blackgram under acid soils

Phosphorus (P) is a fundamental mineral nutrient for crop development and essential in vital physiological processes in pulses. However P availability is restricted to crops because of various reasons. Hence developing solutions for enhancing the bioavailability of P will helps to improve the production of pulses. With this rationale, field experiments were conducted at National Pulses Research Center (NPRC), Vamban during kharif and rabi (2016 to 2018) to study the effect of phosphorus and bioresources viz, phosphobacteria and Arbuscular Mycorrhiza along with Rhizobium on growth, yield and soil nutrient status and economics of blackgram under acid soil condition. The results revealed that, soil based application of inorganic phosphorus @ 50 kg ha−1 + Rhizobium and phosphobacteria each @ 2 kg ha−1 + Arbuscular Mycorrhiza @ 50 kg ha−1 increased yield (941 kg ha−1) which is 20.29% higher than application of P2O5 @ 50 kg ha−1 + Rhizobium and phosphobacteria each @ 2 kg ha−1 (750 kg ha−1). Hence, application of both organic (Rhizobium, phosphobacteria and Arbuscular Mycorrhiza) and inorganic phosphorus resources is better for effective utilization of applied phosphorus for good pod development and yield in a sustainable way for acid soils under alfisol condition.

Isolation and Characterization of Basidiomycetous Yeasts Capable of Producing Phytase under Oligotrophic Conditions.

Phytic acid is an organic phosphorus source naturally produced by plants as phosphorus stock and can be an alternative to rock phosphate, which is a dwindling resource globally. However, phytic acid is insoluble, owing to its binding to divalent metals and is, thus, not readily bioavailable for plants and monogastric livestock. Therefore, the enzyme phytase is indispensable for hydrolyzing phytic acid to liberate free phosphates for nutritional availability, making the screening of novel phytase-producing microbes an attractive research focus to agriculture and animal feed industries. In the present study, a soil-extract-based culture medium was supplemented with phytic acid as the sole phosphorus source and oligotrophic phytase-producing strains, which had not been previously studied, were isolated. Four fungal strains with phytic acid, assimilation activities were isolated. They were found to produce phytase in the culture supernatants and phylogenetic analysis identified three strains as basidiomycetous yeasts (Saitozyma, Leucosporidium, and Malassezia) and one strain as an ascomycetous fungus (Chaetocapnodium). The optimal pH for phytase activity of the strains was 6.0-7.0, suggesting that they are suitable for industrial applications as feed supplements or fertilizer additives for farmland.

Carbohydrate utilization by belowground organs defines the capacity of faba bean to exploit organic phosphorus sources

AbstractBackgroundLimited phosphate (Pi) reserves and the economic and adverse environmental impacts of excessive application of mineral fertilizers in soils are alarming. Therefore, the use of organic phosphorus (Porg) is suggested to reduce reliance on chemical fertilizers.AimsThere is currently little information regarding the accessibility of Porg to N2 fixation plants. Therefore, the present study aims to address the question of to what extent Porg substrates can serve as reliable sources of phosphorus (P) for faba bean in its nodulated phase. Specifically, we intended to explore whether N2‐fixing plants employ intrinsic mechanisms to facilitate Porg availability.MethodsA pot experiment was conducted to assess the inherent capacity of two faba bean varieties (Tiffany vs. Mallory) to utilize Porg supplied as phytic acid and Ca‐glycerophosphate. Plants were inoculated with Rhizobium leguminosarum bv. viciae 3841 strain and cultivated on sterilized loamy sand under greenhouse conditions.ResultsPhytic acid was relatively less efficient than Ca‐glycerophosphate in sustaining plant growth. Compared to Mallory, the variety Tiffany displayed a higher capability to use Porg, as evidenced by the relatively higher biomass production, nodulation, phosphorus use efficiency, and P‐ and N‐accumulations in plant tissues. Porg exploitation was intimately linked to the efficient utilization of the host's carbohydrate budget into nutrient‐acquiring structures (roots and nodules). In addition, the preferential allocation of Pi to prolific nodules is essential for plants to thrive best under these circumstances.ConclusionsTogether with N profitability, these findings suggested that N2‐fixing plants (e.g., faba bean) can promote the sustainable exploitation of Porg, thereby diminishing the sizeable environmental footprint.

Evaluation of High Doses of Phytase in a Low-Phosphorus Diet in Comparison to a Phytate-Free Diet on Performance, Apparent Ileal Digestibility of Nutrients, Bone Mineralization, Intestinal Morphology, and Immune Traits in 21-Day-Old Broiler Chickens.

Simple SummaryPhytic acid is the main storage form for phosphorus in plants. Although it is the main source of organic phosphorus in broiler diets, its utilization by monogastric animals is limited. In addition, phytic acid displays antinutritional effects, impacting optimal nutrient and energy digestibility. The supplementation of feed with phytases enables broilers to use phytate phosphorus more efficiently. Superdosing of phytase has been reported to have additional beneficial effects on the animal beyond the ones derived from the improved phosphorus utilization. This study tried to elucidate the mechanisms related to the immune response and mucosal morphology contributing to those overall beneficial effects. Although addressing performance was not the primary target of the study, performance improved linearly with increasing levels of phytase. The use of increasing doses of phytase showed linear increases in apparent ileal digestibility of crude protein, crude ash, and phosphorus. Jejunal crypt depth decreased with the addition of phytase to a low-protein diet, as well as the content of CD3-positive intraepithelial lymphocytes, but the results could not demonstrate clear differences between phytase doses in these specific parameters.The supplementation of feed with phytases enables broilers to utilize more efficiently phosphorus (P) from phytic acid (IP6), the main storage form of P in plants. The current study evaluated the addition of 500, 1000, and 3000 FTU of phytase per kg to a phytate-containing diet with low P level (LP) fed to broilers from 1 to 21 days of age and compared it to a hypoallergenic phytate-free diet (HPF). There was a linear improvement in performance parameters with increasing levels of phytase in the LP diet (p < 0.001). Apparent ileal digestibility of crude protein, P, and some amino acids, increased with phytase. Crude ash, P, and the calcium content of tibia bones linearly increased with increasing levels of phytase (p < 0.001). Crypt depth (related to body weight) in the jejunum epithelium linearly decreased with phytase addition (p < 0.001). Cecal crypt depth decreased with phytase supplementation (p = 0.002). Cecum tissue showed lower counts of CD3-positive intraepithelial lymphocytes in broilers receiving the phytase in comparison to LP (p < 0.001), achieving similar counts to HPF-fed broilers. Although results from the current study seem to point out some mechanisms related to the immune response and mucosal morphology contributing to those overall beneficial effects, no clear differences between different phytase doses could be demonstrated in these specific parameters.

Agronomic efficiency and genome mining analysis of the wheat-biostimulant rhizospheric bacterium Pseudomonas pergaminensis sp. nov. strain 1008T.

Pseudomonas sp. strain 1008 was isolated from the rhizosphere of field grown wheat plants at the tillering stage in an agricultural plot near Pergamino city, Argentina. Based on its in vitro phosphate solubilizing capacity and the production of IAA, strain 1008 was formulated as an inoculant for bacterization of wheat seeds and subjected to multiple field assays within the period 2010–2017. Pseudomonas sp. strain 1008 showed a robust positive impact on the grain yield (+8% on average) across a number of campaigns, soil properties, seed genotypes, and with no significant influence of the simultaneous seed treatment with a fungicide, strongly supporting the use of this biostimulant bacterium as an agricultural input for promoting the yield of wheat. Full genome sequencing revealed that strain 1008 has the capacity to access a number of sources of inorganic and organic phosphorus, to compete for iron scavenging, to produce auxin, 2,3-butanediol and acetoin, and to metabolize GABA. Additionally, the genome of strain 1008 harbors several loci related to rhizosphere competitiveness, but it is devoid of biosynthetic gene clusters for production of typical secondary metabolites of biocontrol representatives of the Pseudomonas genus. Finally, the phylogenomic, phenotypic, and chemotaxonomic comparative analysis of strain 1008 with related taxa strongly suggests that this wheat rhizospheric biostimulant isolate is a representative of a novel species within the genus Pseudomonas, for which the name Pseudomonas pergaminensis sp. nov. (type strain 1008T = DSM 113453T = ATCC TSD-287T) is proposed.