Phosphate solubilization by microorganisms

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.

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Genomic characterization and computational phenotyping of nitrogen-fixing bacteria isolated from Colombian sugarcane fields

Scientific Reports ◽

10.1038/s41598-021-88380-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Luz K. Medina-Cordoba ◽

Aroon T. Chande ◽

Lavanya Rishishwar ◽

Leonard W. Mayer ◽

Lina C. Valderrama-Aguirre ◽

...

Keyword(s):

Antibiotic Resistance ◽

Nitrogen Fixation ◽

Plant Growth ◽

Phosphate Solubilization ◽

Nitrogen Fixing ◽

Nitrogen Fixing Bacteria ◽

Promising Tool ◽

A Genome ◽

Plant Growth Promoting ◽

Growth Promoting

AbstractPrevious studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.

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Factors determining rock phosphate solubilization by microorganisms isolated from soil

World Journal of Microbiology and Biotechnology ◽

10.1007/bf00327716 ◽

1996 ◽

Vol 12 (6) ◽

pp. 567-572 ◽

Cited By ~ 140

Author(s):

E. Nahas

Keyword(s):

Rock Phosphate ◽

Phosphate Solubilization ◽

Rock Phosphate Solubilization

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Simultaneous phosphate solubilization potential and antifungal activity of new fluorescent pseudomonad strains, Pseudomonas aeruginosa, P. plecoglossicida and P. mosselii

World Journal of Microbiology and Biotechnology ◽

10.1007/s11274-008-9925-x ◽

2008 ◽

Vol 25 (4) ◽

pp. 573-581 ◽

Cited By ~ 69

Author(s):

Babita Kumari Jha ◽

Mohandass Gandhi Pragash ◽

Jean Cletus ◽

Gurusamy Raman ◽

Natarajan Sakthivel

Keyword(s):

Pseudomonas Aeruginosa ◽

Antifungal Activity ◽

Phosphate Solubilization ◽

Fluorescent Pseudomonad

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Induced Inorganic Phosphate Solubilization Through N-Methyl-N´-Nitro-N-Nitrosoguanidine Treated Mutants of Pseudomonas koreensis Strain AK-1 (MTCC Number 12058) Under Polyethylene Glycol

Proceedings of the National Academy of Sciences India Section B Biological Sciences ◽

10.1007/s40011-014-0416-6 ◽

2014 ◽

Vol 86 (1) ◽

pp. 115-123 ◽

Cited By ~ 2

Author(s):

Amrita Kasotia ◽

Devendra Kumar Choudhary

Keyword(s):

Polyethylene Glycol ◽

Inorganic Phosphate ◽

Phosphate Solubilization

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Phosphate Solubilization Potentials of Rhizosphere Fungi Isolated from Insecticide Treated Soil

Advanced Research in Life Sciences ◽

10.2478/arls-2020-0020 ◽

2020 ◽

Vol 4 (1) ◽

pp. 58-69

Author(s):

Babatide Olufemi Oladapo ◽

Esther Aanuoluwa Ekundayo ◽

Mariam Olukemi Mokoolu ◽

Fatuyi Olanipekun Ekundayo

Keyword(s):

Incubation Time ◽

Phosphate Solubilization ◽

Trichoderma Viride ◽

Fungal Species ◽

Rhizosphere Fungi ◽

Optimization Study ◽

Lambda Cyhalothrin ◽

Optimum Ph ◽

Microbiological Techniques ◽

Tricalcium Phosphates

Abstract Insecticides are used widely to control a variety of pests and often residues of these insecticides are left in soil which may have impact on the phosphate solubilization potentials of rhizosphere fungi. Rhizosphere soils were collected from carefully uprooted cowpea seedlings with hand trowel on 50, 70 and 90th days of germination containing the lambda-cyhalothrin and dimethoate insecticides. Fungi associated with the above samples were identified by standard microbiological techniques. Screening for phosphate solubilization potential of the isolates was done by spot inoculation on Pikovskaya agar by measuring the clear zones around the colonies supplemented with tricalcium phosphates [Ca3(PO4)2]. The phosphatase produced by the fungal species was optimized using parameters such as incubation time, pH, temperature, carbon source and nitrogen source in submerged fermentation. The isolated rhizosphere fungi were identified as Rhizopus stolonifer, Aspergillus niger, Aspergillus fumigatus, Aspergillus terreus, Trichoderma viride, Arthroderma fulvum and Fusarium oxysporum. Among the isolates, Trichoderma viride showed the best ability to solubilize phosphate with solubilization index of 2.82 with dimethoate of 12.5ml/L of water. The optimization study for the enzyme production showed that the best incubation time for phosphatase production was 72 hours by Trichoderma viride. It was observed that the optimum pH for production of phosphatase by Trichoderma viride was 6.5. This study suggests that all the isolated fungi especially Trichoderma viride can adapt to these insecticidal treatments, which make them useful as biofertilizers to increase uptake of phosphorous in plants.

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