National Botanical Research Institute Research Articles

Phosphate solubilization and plant growth promotion by two Pantoea strains isolated from the flowers of Hedychium coronarium L.

Phosphorus (P) is an essential macronutrient for plants and is considered as one of the limiting nutrients to plants. The majority of P in the soil is found in the form of insoluble phosphate complexes, making the P unavailable for plants. In the present study, we report two highly efficient phosphate solubilizing bacteria isolated from the closed flower ofHedychium coronariumL., a medicinal plant commonly known as Gulbakawali. Based on morphological, biochemical, and molecular characterization, the two bacterial isolates were identified as genusPantoeaand designated as HCF6 and HCF9. Both these isolates efficiently solubilize tricalcium phosphate [Ca3(PO4)2] present in National Botanical Research Institute’s Phosphate (NBRIP) medium by releasing soluble phosphate up to 2000 μg ml-1and also partially solubilize aluminium phosphate (AlPO4). HCF6 and HCF9 possess several plant growth promoting traits and were evaluated for plant growth promotion ability using sand as a growth medium. Wheat plants treated with the bacterial isolates had increased root and shoot length and plant dry mass and accumulated higher inorganic phosphate in the plant tissue suggesting their role in mobilizing soluble P from insoluble P-complexes. Overall, our findings suggest that both thesePantoeaisolates (HCF6 and HCF9) represent promising candidates as bioinoculants.

Screening and evaluation of phosphate-solubilizing bacteria isolated from aquaculture ponds in a step-by-step strategy as potential biofertilizer.

The application of phosphate-solubilizing bacteria (PSB) has received little attention in aquaculture. In addition, the low efficiency of PSB as a biofertilizer in farm conditions is a major concern. Therefore, this study aims to isolate the PSB from sediment of earthen fishponds and evaluate with a more appropriate approach to ensure their effectiveness in increasing the bioavailability of phosphorus (P) in farm conditions. PSB was first isolated and selected using the National Botanical Research Institute's Phosphate (NBRIP) medium-containing tri-calcium phosphate (TCP) in solid and liquid media. Among 96 strains that were isolated, 11 strains identified by 16 s rRNA, belonging to the genera Pseudomonas and Acinetobacter, showed a higher ability to release P from TCP (48-170 mg L-1 ). Then, the efficiency of 11 strains was evaluated by combining different criteria. Among 11 selected strains, based on the ability to dissolve TCP and Ca-Phytate in culture medium, release P in sediment microcosm, and growth in a wide range of environmental conditions in fishponds, especially optimum growth at 4°C and pH above 8, Ps. deceptionensis strain Persian10 was selected as the most efficient strain for testing in aquarium conditions. In the last step, incubation of Persian10 in aquarium sediment (sterilized under gamma-ray) increased soluble P and had an impact on calcium phosphate, organic P and alkaline phosphatase activity; however, Persian10 had no impact on the concentration of iron phosphate and aluminium phosphate. Persian 10 strain can be considered a bio-fertilizer candidate in earthen fishponds as it expressed the ability to solubilize P in different conditions. It is very important to evaluate PSB in an appropriate process using a combination of different criteria to ensure optimal performance of PSB in farm conditions.

Phosphate-Solubilizing Bacteria Isolated from Phosphate Solid Sludge and Their Ability to Solubilize Three Inorganic Phosphate Forms: Calcium, Iron, and Aluminum Phosphates.

Biofertilizers are a key component of organic agriculture. Bacterial biofertilizers enhance plant growth through a variety of mechanisms, including soil compound mobilization and phosphate solubilizing bacteria (PSB), which convert insoluble phosphorus to plant-available forms. This specificity of PSB allows them to be used as biofertilizers in order to increase P availability, which is an immobile element in the soil. The objective of our study is to assess the capacity of PSB strains isolated from phosphate solid sludge to solubilize three forms of inorganic phosphates: tricalcium phosphate (Ca3(PO4)2), aluminum phosphate (AlPO4), and iron phosphate (FePO4), in order to select efficient solubilization strains and use them as biofertilizers in any type of soil, either acidic or calcareous soil. Nine strains were selected and they were evaluated for their ability to dissolve phosphate in the National Botanical Research Institute’s Phosphate (NBRIP) medium with each form of phosphate (Ca3(PO4)2, AlPO4, and FePO4) as the sole source of phosphorus. The phosphate solubilizing activity was assessed by the vanadate-molybdate method. All the strains tested showed significantly (p ≤ 0.05) the ability to solubilize the three different forms of phosphates, with a variation between strains, and all strains solubilized Ca3(PO4)2 more than FePO4 and AlPO4.

Isolation and selection of salt-tolerant bacterial strains capable of solubilizing phosphorus and synthesizing phosphatase enzyme from rice-shrimp soil in Mekong River Delta, Vietnam

The aim of this study was to isolate and select salt tolerant bacteria having both functions in phosphorus solubilization and phosphatase synthesis from rice-shrimp farming soil in saline areas in Mekong River Delta of Vietnam. Phosphorus solubilizing bacteria were isolated on National Botanical Research Institute's Phosphate (NBRIP) agar medium containing 1% NaCl and the activity of phosphatase enzyme was determined by disodium p-nitrophenyl phosphate reagent method at a wavelength of 420 nm. The result showed that from 15 saline soil samples, a total of 95 strains of phosphorus solubilizing bacteria were isolated and 19 of them showed their good phosphorus solubilization. The results about phosphatase activities of these 19 strains illustrated that TBT5-3 bacterial strain was the highest phosphatase producing strain with an amount of 0.377 U/mL after 10 days of incubation. This strain showed its best phosphatase producing capacity when cultured in the liquid culture medium containing pH 5, 1% NaCl, glucose and urea under the shaking speed of 120 rpm. Based on 16S rRNA gene sequence analysis this phosphatase synthesizing bacterial strain was genetically identified as species of Bacillus sp. TBT5-3 since 100% of this train sequence is affiliated with Bacillus megaterium.

Effect of Native Trichoderma asperellum Isolate on Phosphate Solubilization and Growth of Pea

Application of phosphorus solubilizing microbes is a promising tool for enhancing P uptake in plant. The aim of this study was to evaluate the phosphate solubilization potential and growth promotion of pea (Pisum sativum L.) by native Trichoderma asperellum isolate G3. Phosphate solubilization by T. asperellum strain was assessed in National Botanical Research Institute’s Phosphate (NBRIP) broth medium. Pea plants were inoculated by Trichoderma strain and grown in pot in phosphate deficit condition. The fungal strain was able to solubilize phosphate (from 188.95±2.04 to 262.50±3.80 mgL-1) in broth at different time periods and decreased solution pH. The Trichoderma inoculated pea plant increased the root growth, shoot growth, leaf number, shoot biomass, root biomass, total dry weight, chlorophyll a, chlorophyll b and carotenoid by 23.9%, 33.3%, 33%, 37.1%, 32.7%, 28.4%, 24.5%, 17.4% and 14.7% respectively over control after 5 weeks of post inoculation. The results showed that the native T. asperellum isolate G3 has great potential in the phosphorus solubilization. Ann. Bangladesh Agric. (2020) 24(2) : 121-124

Salt Tolerant Rhizobacteria from Coastal Region of Bangladesh Portrayed the Potential for Plant Growth Promotion

Plant growth-promoting rhizobacteria can effectively reduce the severity of different abiotic stresses like water stress, temperature stress, salt stress, etc. on plant growth and development. The study aimed at isolating salt-tolerant rhizobacteria followed by their morphological, biochemical and plant growth promotion traits evaluation. Sixteen root samples of nine different plant species were collected from two locations of Patuakhali, a coastal southern district of Bangladesh. Thirty rhizobacteria were isolated, fifteen from each location, to assess their halotolerance and plant growth promoting potential. The isolated rhizobacteria were subjected to morphological (viz. shape, colour and elevation), biochemical (viz. Gram reaction, catalase test and HCN production) and growth-promoting traits [viz. phosphate solubilizing ability, salt tolerance, indole-3-acetic acid (IAA) production, and N2-fixation] characterization. Twenty-eight isolates were Gram positive, 27 were catalase positive, and nine showed varying degrees of phosphate solubilization on National Botanical Research Institute of Phosphate (NBRIP) medium. Isolate PWB5 showed the highest phosphate solubilizing index (PSI = 3.83±0.098) on the 6th day. To screen salt-tolerant rhizobacteria, the isolates were cultured in NBA media containing different (0%, 2.5%, 5%, 7.5%, 10%, 12%, 15%) NaCl concentrations. Isolate PWB12 and PWB13 grew at 15% NaCl concentration. Eleven isolates exhibited IAA producing ability on Winogradsky medium amended with L-tryptophan among which four (PMB13, PMB14, PMB15 and PWB6) were strong IAA producers. Twenty-seven isolates were potential N2-fixer and among them, 20 were highly efficient, but none of the isolates was HCN producer. The rhizobacteria isolated in the current research work showed some potential plant growth-promoting traits which seem applicable for crop production, especially, under salt stress condition.

Seed bio-priming with tri-species consortia of phosphate solubilizing rhizobacteria (PSR) and its effect on plant growth promotion

Three potential rhizobacteria namely Burkholderia gladioli (MTCC 10216), Pseudomonas sp. (MTCC 9002) and Bacillus subtilis (MTCC 8528) procured from IMTECH, Chandigarh (India) were evaluated individually and as consortia for its phosphate (P) solubilizing ability and effect of growth of fenugreek (Trigonella foenum-graecum L.) and tomato (Lycopersicon esculentum L.). Phosphate solubilizing ability of these strains individually and as consortia was tested on Pikovskayas agar medium, Phosphate solubilizing agar medium and National Botanical Research Institute phosphate agar medium containing six different sources of insoluble inorganic phosphate such as tri-calcium phosphate (TCP), di-calcium phosphate (DCP), zinc phosphate (ZP), ferric phosphate (FP), sodium di-hydrogen phosphate (SP), and aluminum phosphate (AP), and two organic P such as calcium and sodium phytate. The maximum P solubilizing ability was recorded in consortium-4 having all three potential bacterial strains. Phosphate solubilization after 7th day of incubation was 37.9 mg/100 ml of TCP, 40.01 mg/100 ml of DCP, 15.79 mg/100 ml of FP, 43.02 mg/100 ml of SP, no solubilization of ZP and AP, 39.75 mg/100 ml of calcium phytate and 24.01mg/100 ml of sodium phytate. Seed germination and the other plant parameters such as plant height and weight significantly increased in fenugreek and tomato seeds, bio-primed with consortium-4 followed by consortium-3. After bio-priming of seeds in pot assay, the level of phosphorus in soil got increased by 54% in consortium-4 treated soil followed by consortium-3 (47%) over untreated control soil. Based on these findings, consoritium-4 could be recommended as a good bio-inoculant for fenugreek, tomato and other crops in comparison to individual strains and other consortia.

Screening and optimization of indole-3-acetic acid production and phosphate solubilization by rhizobacterial strains isolated from Acacia cyanophylla root nodules and their effects on its plant growth

BackgroundPlant growth-promoting rhizobacteria (PGPR) are known to improve plant growth and are used as biofertilizers, thanks to their numerous benefits to agriculture such as phosphorus solubilization and phytohormone production. In this paper, four rhizospheric bacteria (Phyllobacterium sp., Bacillus sp., Agrobacterium sp., and Rhizobium sp.) isolated from surface-sterilized root nodules of Acacia cyanophylla were tested for their ability to solubilize inorganic phosphate and to produce indole-3-acetic acid (IAA) under laboratory conditions. Then, the best IAA producer (Rhizobium sp.) was selected to test optimized conditions for IAA production. Finally, the effect of the four strains on plant growth for A. cyanophylla was evaluated in vivo. ResultsThe results showed that the totality of the tested isolates had solubilized inorganic phosphate (P) in both NBRIP (National Botanical Research Institute Phosphate) and PVK (Pikovskaya) media. Bacillus sp. was a high P-solubilizer and showed maximum solubilization in PVK (519 μg ml-1) and NBRIP (782 μg ml-1). The optimization of maximum phosphate solubilization was done using different sources of carbon (1%) and nitrogen (0.1%). Glucose and ammonium sulfate were selected to be the best carbon and nitrogen source for phosphate solubilization by all tested strains, except for Phyllobacterium sp., which recorded the highest phosphate solubilization with ammonium nitrate. The IAA production by the tested strains indicated that Rhizobium sp. produced the highest amount of IAA (90.21 μg ml-1) in culture media supplemented with L-tryptophan. The best production was observed with L-Trp concentration of 0.2% (116.42 μg ml-1) and at an initial pH of 9 (116.07 μg ml-1). The effect of NaCl on IAA production was tested at concentrations of 0 to 5% and the maximum production of 89.43 μg ml-1 was found at 2% NaCl. The extraction of crude IAA from this strain was done and purity was confirmed with Thin Layer Chromatography (TLC) analysis. A specific spot from the extracted IAA production was found to correspond with a standard spot of IAA with the same Rf value. Finally, the tested PGPR demonstrated growth stimulatory effects on Acacia cyanophylla seedlings in vivo, with a great increase of shoots’ and roots’ dry weights, and shoot length compared to control.The rhizobacterial isolates were identified by 16S rDNA sequence analysis as Agrobacterium sp. NA11001, Phyllobacterium sp. C65, Bacillus sp. CS14, and Rhizobium sp. V3E1. ConclusionThis study highlights the importance of the use of phosphate solubilizing and IAA producer microorganisms as biofertilizers to increase crop yields. The studied strains showed a significant phosphate solubilization potential and IAA production. The use of selected strains as inoculants would be interesting, in particular with a view of promoting sustainable agriculture. However, further studies to verify the efficacy of the best isolates in situ is certainly required.

Moringa Oleifera: A Bibliometric Analysis of India’s Publications During 1980-2019

The study examines India’s research publications on Moringa oleifera plant during 1980-2019, as indexed in Scopus database, focusing on aspects, such as growth characteristics, research quality and impact, extent of international collaborative papers, distribution by broad subjects and significant keywords, leading organizations, authors and journals and features of its high-cited papers. The study found that CFTRI - Mysore (21 papers), University of Calcutta (18 papers) and Banasthali Vidyapeeth (15 papers) were the most productive organizations and National Botanical Research Institute, Lucknow (79.27 and 4.12), Sri Venkateswara University, Tirupati (55.82 and 2.90) and Banaras Hindu University, Varanasi (40.7 and 2.12) were the most impactful organizations in terms of citation per paper and relative citation index. A. Mehta (10 papers), V. Sharma (10 papers) and D. Guha (9 papers) were the most productive authors and S.J.S. Flora (103.33 and 5.38), A. Urooj (36.50 and 1.90) and A.A. Mehta (20.5 and 1.59) were the most impactful authors in terms of citation per paper and relative citation index. International Journal of Pharmacy and Pharmaceutical Sciences (21 papers), Asian Journal of Pharmaceutical and Clinical Research and Journal of Ethnopharmacology (19 papers each) were the leading journals contributing to the field. Journal of Ethnopharmacology (75.0), Phytotherapy Research (52.75) and Indian Journal of Experimental Biology (33.33) were found to be most impactful journals in terms of citation per paper. Key words: Moringa oleifera, Medicinal plant, Indian publications, Scientometrics, Bibliometrics.

Usnea dasaea, a further new addition to the Lichen Flora of Tamil Nadu State, India

The present study addresses the addition of one new fruticose lichen species for the first time to the state of Tamil Nadu in Western Ghats, India. Usnea dasaea Stirt. is a new occurrence in Tamil Nadu. Descriptions of identification keys and distributions of such new species in south India provide useful information for identification. The new species addition of such lichen was identified and deposited at lichen herbaria, National Botanical Research Institute, Lucknow, Uttar Pradesh, India and Bharathiar University, Coimbatore, Tamil Nadu, India for further studies.

Biosolubilization of Low-Grade Rock Phosphate by Native Microbial Consortia from Phosphate Mines: Effect of Sampling Sources and Culture Media

Two native microbial consortia were isolated from the soil and drainage in the phosphate mines, and their abilities to solubilize low-grade rock phosphate (RP) in two different culture media, namely Pikovskaya (PKV) and National Botanical Research Institute’s phosphate (NBRIP) medium, respectively, were estimated. Results showed that the two microbial consortia could grow steadily in the solution and continuously released soluble phosphate from the RP during 14 d of experiments. This process was accompanied by a drop in pH of the solution. The microbial consortium isolated from the soil achieved the largest release of soluble phosphate and pH reduction in the PKV medium among the four microbial consortia named PS, NS, PD, and ND, respectively. Fourier transform infrared spectroscopy (FTIR) analysis of RP indicated that hydroxyl, alkyl C-H bond, amide, and carboxyl were involved in the RP solubilization, and significant changes of them were observed after the experiments. The four microbial consortia were sampled before and after the experiments for the analysis of their bacterial and fungal community structures by Illumina MiSeq sequencing. Results showed that the relative diversities and abundances of the dominant bacteria and fungi varied with different sampling sources (soil and drainage) and culture media (PKV and NBRIP medium).

Effects of Phosphate Solubilizing Microorganisms on Wheat Yield and Phosphatase Activity

PHOSPHATE solubilizing capacity of four strains, Pseudomonas fluorescence, Bacillus megaterium, Serratia marcescens, and Bacillus subtilis was assessed in liquid National Botanical Research Institute’s phosphate medium containing rock phosphate (RP). A greenhouse pot experiment was conducted to evaluate the effects of inoculation with arbuscular mycorrhizal (AM) fungi alone or in combination with each strain with and without RP on wheat (Triticum aestivum Gemeza-9) growth, yield, nutrient uptake and the activity of alkaline phosphatase. The amounts of P released from RP by bacterial strains ranged from 0.22 to 80.8mg P L-1 and the pH values of the cultures were reduced from initial value of 7.3 to values varied between 4.04 and 6.62. The results indicated that B. subtilis was the most effective strain in solubilizing RP in liquid culture. The combined inoculation with bacterial strains and AM fungi led to a significant increase in soil P content and alkaline phosphatase activity compared with both the non-inoculated and the individually inoculated soil, and this increase was much higher after 69 days comparing with those after 130 days. In RP-amended soil, B. subtilis and P. fluorescence were more effective in increasing NPK uptake of wheat straw and grains compared with S. marcescens and B. megaterium when inoculated with AM fungi. This study is concluded that the combined inoculation plus RP gave better results for wheat grown in sandy soil. Further researches are required to estimate this study under field conditions and different soils to give reliable results.

Effect of elevated CO2 on litter functional traits, mass loss and nutrient release of two subtropical species in free air carbon enrichment facility

Assessing the impact of increasing carbon dioxide (CO2) on nutrient cycling requires understanding of the relationship between the concentration of CO2 and litter dynamics. It is, therefore necessary to understand leaf litter traits in response to increased atmospheric CO2. Variations in plant litter chemistry under elevated carbon dioxide (e−CO2) are the critical factors in ecosystem feedback. Litter fall, litter substrate quality, nutrient flux and decay rate in two tropical tree of Tectona grandis (Teak) and Butea monosperma (Butea) were examined. Saplings were exposed to elevated CO2 treatment (e−CO2 -550 ppm) and ambient CO2 (a−CO2; - 395 ppm) in the FACE (Free air CO2 enrichment) facility in CSIR- National Botanical Research Institute in Indo-Gangetic plain region. Litter was analysed for concentrations of carbon (C), nitrogen (N), soluble sugars (SS), lipids, lignin, cellulose, hemi-cellulose (HC) and C-based defensive compounds; soluble phenolics (SP). Nutrient concentration in naturally senesced litter for Butea and Teak was significantly different in elevated and ambient rings. Elevated CO2 significantly increased C/N (+8.27 % and +21.94 %), lowered mean litter N concentration (–3.27 % and -12.15 %), and affected the concentrations of soluble sugars, soluble phenolic and lipids in leaf litter of Butea and Teak plantations, respectively. Increase in litter biomass production (+19.75 % and 22.84 %) for both the plants under e−CO2, resulted in significant increase in the flux of N, SS, SP and lipid in to the soil. Elevated CO2 increased cellulose (+18.21 %; 12.30 %), hemicellulose (+8.48 %; +10.18 %) and lignin inputs to soils (+35.22; +43.36 %) in Butea and Teak plantation respectively. The study indicated that changes in litter biomass production and litter substrate quality during exposure to e−CO2 could significantly alter the input of nitrogen, soluble phenolic, soluble sugars, lipids, cellulose, and lignin to soils, and so also the biogeochemical cycle of the prevailing ecosystem.

Isolation and selection of highly effective phosphate solubilizing bacterial strains to promote wheat growth in Egyptian calcareous soils

BackgroundForty phosphate solubilizing bacterial (PSB) isolates were isolated from the root zone of wheat plants cultivated in the Delta and the Northwestern coast regions of Egypt. All isolates proofed their ability to dissolve tricalcium phosphate on the National Botanical Research Institute's phosphate growth medium (NBRIP) by producing clear zone and increasing the available phosphorus that ranged between 40 and 707 mg l−1. They were designated as Egyptian native phosphate solubilizing bacteria (ENPSB).ResultsAll strains proofed their ability to dissolve tricalcium phosphate on (NBRIP) medium by producing clear zone and increasing the available phosphorus that ranged between 40 and 707 mg l−1. The ENPSB 1, 2, and 3 strains were highly efficient as they gave 707, 653, and 693 mg l−1 soluble phosphorus respectively. Intriguingly, the two highly efficient strains for phosphate solubilization were isolated from the Northwestern coast alkaline soils. Moreover, 75% of strains were also produced profitable amounts of indole acetic acid (IAA) ranged from 0.79 to 50.5 mg l−1. Amazingly, the most efficient strain ENPSB 1 in solubilizing phosphorus (707 mg l−1soluble P) was the best one for producing IAA (50.5 mg l−1). The three efficient strains were identified using the sequencing of 16S rRNA. Sequence analysis of 16S rRNA for selected strains confirmed that the strains ENPSB 1, 2, and 3 were genetically closed to Enterobacter aerogenes; Pantoea sp. and Enteriobacter sp. respectively.ConclusionThe inoculation by mix cultures of strains (ENPSB 1, 2, and 3) contributed to raising the dry weight and P content of wheat plants by 76% and 12% over the full fertilized plants. Inoculation of soil PSB can be used to solve the deficiency of phosphorus and promote plant growth effectively in calcareous soils.

Screening and Isolation of Effective Microbes for Decomposition Process among Different Organic Waste

Organic waste is material that is biodegradable and comes from either plant or animal. It can be decomposed over time by microbes into methane, carbon dioxide, water, and other simple organic molecules. Microorganism especially bacteria and fungus are able to decompose cellulose by an enzyme known as cellulase. Since plants are made up from cellulose, this study is focused on isolating and identifying the microbes that are responsible in decomposing the organic waste by screening for the microorganisms that are able to produce cellulose enzyme. In this experiment, the bacteria were isolated from three different samples, which are; compost product, decayed wood and empty fruit bunch mix with oil palm frond. The samples were collected from the fresh decomposing organic waste. The samples undergo serial dilution, screening the ability of the microorganism to solubilize phosphate by using National Botanical Research Institute’s Phosphate media (NBRIP) and screening the ability of the microorganism to produce cellulose enzyme by using Carboxymethyl Cellulose Media (CMC) treated with Congo Red and NaCl for confirmation of the targeted effective microbes. The result shows that the targeted effective microbes will produce the halo zone or clear zone formation after being treated with Red Congo and NaCl solution on CMC media and producing a halo zone on NBRIP media. In this experiment, we manage to isolate and identify the bacteria that is responsible in producing cellulase enzyme and solubilizing phosphate that is known as Streptomyces sanglieri. Application of effective microbes will promote the plant uptake due to its ability in converting the nutrient into available form to the plant.

Characteristics of Inorganic Phosphate-Solubilizing Bacteria from the Sediments of a Eutrophic Lake.

Inorganic phosphate-solubilizing bacteria (IPB) are an important component of microbial populations in lake sediments. The phosphate that they decompose and release becomes an important source of phosphorus for eutrophic algae. The IPB strains were screened and isolated from the sediments of Sancha Lake using National Botanical Research Institute’s phosphate (NBRIP) plates. Their taxonomy was further determined by the 16S rDNA technique. The tricalcium phosphate-solubilizing ability of obtained IPB strains was evaluated using NBRIP- bromophenol blue (BPB) plates and Pikovskaya (PVK) liquid medium. Then, the ability of IPB strains to release phosphorus from the sediments were investigated by mimicking the lake environment. In this study, a total of 43 IPB strains were screened and isolated from the sediments of Sancha Lake, belonging to three phyla, eight families, and ten genera. Among them, two potentially new strains, SWSI1728 and SWSI1734, belonged to genus Bacillus, and a potentially new strain, SWSI1719, belonged to family Micromonosporaceae. Overall, the IBP strains were highly diverse and Bacillus and Paenibacillus were the dominant genera. In the tricalcium phosphate-solubilizing experiment, only 30 of the 43 IPB strains exhibited clear halo zones on plates, while in the liquid culture experiment, all strains were able to dissolve tricalcium phosphate. The phosphate-solubilizing abilities of the strains varied significantly, and the strain SWSI1725 of the Bacillus genus showed the strongest ability with a phosphate-solubilizing content of 103.57 mg/L. The sterilized systems demonstrated significantly elevated phosphorus hydrochloride (HCl–P) decomposition and release from the sediments after the inoculation of IPB strains, whereas no significant effect was demonstrated on the phosphonium hydroxide (NaOH-P). Thus, the IPB strains in the sediments of Sancha Lake possessed rich diversity and the ability to release phosphorus in sediments.

Isolation and identification of phosphate solubilizing bacteria and evaluate its effect on of Mung bean (Vigna radita [L.] R.Wilczek) growth

Sixteen soil samples were collected from wheat, barley and yellow corn rhizosphere in Abu-Ghraib, Aqraqof, Latifieh,Tarmiah, Jadriya and of Agriculture in Baghdad university/ Baghdad city. The results found nine phosphate solubilizing bacteria (PSB) isolates (Y1, Y2, Y3, Y4, Y5, Y6, Y7, Y8, Y9), formed clear zones on National Botanical Research Institute's (NBRIP) agar. The solubility index (SI) of PSB isolates ranged from 2.00 to 3.66. Y4 have the highest SI (3.66) followed by Y3 and Y6 (3.33). Phosphate solubilization abilities varying from (20.10-39.00 μg.ml-1), Y4 was the highest (39.00 μg.ml-1) followed by Y3 (37.00μg.ml-1). The results of hydrolytic enzymes production showed that almost all nine isolates are able to produce protease and pectinase, while Y1 and Y2 showed negative results in cellulase production. Maximum ability for hydrogen cyanide (HCN) and indole acetic acid (IAA) production were showed byY3 and Y4 isolates. The isolate Y4 was found to be the most efficient isolate, so it was selected identified as Bacillus cereus using biochemical tests confirmed by VITEC 2 compact system. The results of High performance liquid chromatography (HPLC) revealed that Bacillus cereus produce oxalic acid (2.996), citric acid (9.117) and malic acid (3.734). Bacillus cereus (Y4) enhanced the growth of mung bean plants. A significant increase in branches number (12.33), plant length (83.0cm), fresh weight (27.25 g) and dry weight (1.427g) were obtained compared with control treatments. The main objective of this study is to isolate PSB and evaluate their roles in plant growth promotion. The results showed the high phosphate solubilization efficiency of PSB isolates and the identified isolates was found to be good enough for plant growth promoting.

Sidrophore Production and Phosphate Solubilization by Bacillus cereus and Pseudomonas fluorescens Isolated from Iraqi Soils and Soil Characterization

This study was conducted to explore the ability of Pseudomonas fluorescens and Bacillus cereus to solubilizing a phosphate in soil for enhancing the planting growth and, its relation with soill characterization. The isolates were identified as P.fluorescens and B. cereus using convential analysis and, its phosphate solubilization ability and sidrophore was shown by the clear zone formation on National Botanical Research Institute’s Phosphate medium. Moreover, Pseudomonas fluorescens isolates (n = 9) and three of B. cereus isolated from agricultural area in Baghdad university, Mustansiriyah university and Diyala bridge. Results displayed that bacterial count were varied in soil samples according to their region,,and ranging from 30 to 60 *10 2 CFU/g in Baghdad university soil to 10—20 *10 2 CFU/g in Mustansiriyah university soil ,.,the Baghdad soil macronutrient which included: NH4 , NO3 ,P,and K were ., 8.42 , 20.53 , 19.09 218.73 respectively, While the physio analysis revealed that the mean of pH was 7.3 and EC was 8.63. on the other hand the micronutrient analysis indicated that the soil samples were included Ca ,Fe ,Mn ,Zn and Cu which gave their mean 5025.9 , 8.9, 4.9, 0.5 and 1.5 respectevily. Results revealed that all isolated bacteria (9 isolates of P.fluorescens and three isolates of B. cereus gave ahalo zone which mean their ability to be phosphate solubilizing bacteria at 100%. Results revealed that all isolated bacteria were detected a ability to produce high levels from chelating agents(( siderophores)) by P.fluorescens and. B cereus at 100%,when appeared ahalo clear zone. Furthermore, the high levels of phosphate solubilization and siderophore production were grouped in bacterial species isolated from Iraqi soils. might be attributed to many soil factors such as soil nutrient status, soil acidity, water content, organic matter and soil enzyme activities.

Isolation and identification of a phosphate-solubilizing Paenibacillus polymyxa strain GOL 0202 from durum wheat (Triticum durum Desf.) rhizosphere and its effect on some seedlings morphophysiological parameters

Abstract Paenibacillus polymyxa is a common bacterium, belonging to Plant Growth Promoting Rhizobacteria (PGPR). It is found in soils, roots and rhizosphere of various crop plants especially wheat. This bacterium has a great biotechnological potential in sustainable agriculture. Indeed, in the rhizosphere, P. polymyxa is involved in nitrogen fixation, production of phytohormones, exoplysaccharides, hydrolytic enzymes and antibiotics, in the enhancement of soil porosity and in soil phosphorus solubilization. In this study, we have identified GOL 0202 strain as Paenibacillus polymyxa, isolated from durum wheat (Triticum durum Desf.) rhizosphere collected from arid region soil of Southern. This genomic identification was performed by 16S rRNA gene sequencing. It was shown that this strain possesses an interesting phosphate solubilization activity on NBRIP (National Botanical Research Institute Phosphorus) medium containing tricalcium phosphate (Ca3 (PO4)2). This activity, was recorded over five days, it was negatively correlated with pH medium whose decline was due probably to the release of organic acids. In addition to other activities associated with P. polymyxa, this availability of soluble phosphate has allowed the improvement of durum wheat seedlings growth estimated through dry weight, chlorophylls and proteins contents. Hence, P. polymyxa GOL 0202 could be used for their targeted application as bioinoculant.

Biosynthesis and characterization of hydroxyapatite and its composite (hydroxyapatite-gelatin-chitosan-fibrin-bone ash) for bone tissue engineering applications.

Hydroxyapatite (HAp) is a bioactive and biocompatible material possessing osteoconductive properties used widely in the biomedical sector. In the present study, synthesis of hydroxyapatite (HAp) using a Klebsiella pneumoniae SM24 (phosphate solubilizing bacteria) isolated from the slaughterhouse. HAp synthesized using biological source showed efficient and positive enzymatic activity in the National Botanical Research Institute Phosphate Medium (NBRIP). Characterization of HAp using FTIR revealed the presence of phosphate group hydroxyapatite and XRD spectra showed polycrystalline nature. The morphological characterization of HAp using FESEM revealed the mesoporous structure and EDX spectrum indicated presence of Ca and P as the major components. In addition, a new bone composite was prepared using the synthesized HAp, Gelatine (G), Chitosan (C), Fibrin (F) and Bone ash (HApGCF) using Simulated Body Fluid (SBF) solution. The confirmation of chemical and structural characteristics of HApGCF bone composite was achieved using FTIR, XRD and SEM analyses. The HApGCF bone composite was tested over osteoblast MG-63 cells showing effective biocompatibility and osteoblast attachment on the composite surface. Therefore, the present report proposes the in vitro application of HApGCF bone composite as a replacement for major bone damage and injury in a biocompatible and non-toxic way.