Tricalcium phosphate solubilization and nitrogen fixation by newly isolated Aneurinibacillus aneurinilyticus CKMV1 from rhizosphere of Valeriana jatamansi and its growth promotional effect

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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PHOSPHATE SOLUBILIZATION BY FUNGI ASSOCIATED WITH LEGUME ROOT NODULES

Canadian Journal of Microbiology ◽

10.1139/m67-099 ◽

1967 ◽

Vol 13 (7) ◽

pp. 749-753 ◽

Cited By ~ 29

Author(s):

P. K. Chhonkar ◽

N. S. Subba-Rao

Keyword(s):

Tricalcium Phosphate ◽

Phosphate Solubilization ◽

Root Nodules ◽

Potassium Dihydrogen Phosphate ◽

Dihydrogen Phosphate ◽

Potassium Dihydrogen ◽

Aspergillus Sp ◽

Phosphate Solubilizing

Phosphate solubilizing ability of different isolates of fungi associated with legume root nodules was studied in vitro. Among the fungi tested, isolates of Penicillium lilacinum, Aspergillus sp., A. flavus, A. niger, A. terreus, and A. nidulans solubilized insoluble tricalcium phosphate. When soluble potassium dihydrogen phosphate was present with tricalcium phosphate in the medium, some of the fungi failed to solubilize phosphate.

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Biological nitrogen fixation and phosphate solubilization by bacteria isolated from tropical soils

Plant and Soil ◽

10.1007/s11104-012-1157-z ◽

2012 ◽

Vol 357 (1-2) ◽

pp. 289-307 ◽

Cited By ~ 74

Author(s):

Leandro Marciano Marra ◽

Cláudio Roberto Fonsêca Sousa Soares ◽

Silvia Maria de Oliveira ◽

Paulo Ademar Avelar Ferreira ◽

Bruno Lima Soares ◽

...

Keyword(s):

Nitrogen Fixation ◽

Biological Nitrogen Fixation ◽

Phosphate Solubilization ◽

Tropical Soils ◽

Biological Nitrogen

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Cultivable mushroom growth-promoting bacteria and their impact on Agaricus blazei productivity

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2013000600009 ◽

2013 ◽

Vol 48 (6) ◽

pp. 636-644 ◽

Cited By ~ 10

Author(s):

Li-Sen Young ◽

Jiunn-Nan Chu ◽

Asif Hameed ◽

Chiu-Chung Young

Keyword(s):

Nitrogen Fixation ◽

Protein Complex ◽

Phosphate Solubilization ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Agaricus Blazei ◽

Bacterial Isolates ◽

Mycelium Growth ◽

Growth Promoting ◽

Solubilization Ability

The objective of this work was to identify growth-promoting bacteria isolated from Agaricus blazei and to evaluate their effect on mushroom mycelial growth and productivity. A total of 56 A. blazei-associated bacterial isolates were obtained from casing soil and identified by 16S rRNA gene sequencing. Bacteria were evaluated as to phosphate-solubilization ability, nitrogen-fixation capability, and secretion of cellulase. Superior isolates were tested for their to effect on A. blazei productivity, micelial growth, and on the contents of the polysaccharide-protein complex and of N, P, K, Ca, and Mg. Bacterial isolates were identified as actinobacteria (60%), firmicutes (20%), and proteobacteria (20%). Among them, ten isolates had phosphate-solubilization ability, eight showed nitrogen-fixation capability, and 12 isolates promoted A. blazei mycelium growth. Bacterial inoculation reduces time till harvest in up to 26 days, increases fresh mushroom yield up to 215%, and increases total polysaccharide-protein complex content twofold when compared to the non-inoculated control. The actinobacteria group is the predominant A. blazei-associated phylum.

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Characterization of Arsenic-Resistant Endophytic Bacteria From Alfalfa and Chickpea Plants

Frontiers in Plant Science ◽

10.3389/fpls.2021.696750 ◽

2021 ◽

Vol 12 ◽

Author(s):

Hazhir Tashan ◽

Behrouz Harighi ◽

Jalal Rostamzadeh ◽

Abdolbaset Azizi

Keyword(s):

Nitrogen Fixation ◽

Plant Growth ◽

Endophytic Bacteria ◽

Phosphate Solubilization ◽

Lipase Production ◽

Growth Potential ◽

Sodium Arsenate ◽

Plant Growth Promoting ◽

Growth Promoting

The present investigation was carried out to isolate arsenic (As)-resistant endophytic bacteria from the roots of alfalfa and chickpea plants grown in arsenic-contamination soil, characterize their As tolerance ability, plant growth-promoting characteristics, and their role to induce As resistance by the plant. A total of four root endophytic bacteria were isolated from plants grown in As-contaminated soil (160–260-mg As kg−1 of soil). These isolates were studied for plant growth-promoting (PGP) characteristics through siderophore, phosphate solubilization, nitrogen fixation, protease, and lipase production, and the presence of the arsenate reductase (arsC) gene. Based on 16S rDNA sequence analysis, these isolates belong to the genera Acinetobacter, Pseudomonas, and Rahnella. All isolates were found As tolerant, of which one isolate, Pseudomonas sp. QNC1, showed the highest tolerance up to 350-mM concentration in the LB medium. All isolates exhibited phosphate solubilization activity. Siderophore production activity was shown by only Pseudomonas sp. QNC1, while nitrogen fixation activity was shown by only Rahnella sp. QNC2 isolate. Acinetobacter sp. QNA1, QNA2, and Rahnella sp. QNC2 exhibited lipase production, while only Pseudomonas sp. QNC1 was able to produce protease. The presence of the arsC gene was detected in all isolates. The effect of endophytic bacteria on biomass production of alfalfa and chickpea in five levels of arsenic concentrations (0-, 10-, 50-, 75-, and 100-mg kg−1 soil) was evaluated. The fresh and dry weights of roots of alfalfa and chickpea plants were decreased as the arsenic concentration of the soil was increased. Results indicate that the fresh and dry root weights of alfalfa and chickpea plants were significantly higher in endophytic bacteria-treated plants compared with non-treated plants. Inoculation of chickpea plants with Pseudomonas sp. QNC1 and Rahnella sp. QNC2 induced lower NPR3 gene expression in chickpea roots grown in soil with the final concentration of 100-mg kg−1 sodium arsenate compared with the non-endophyte-treated control. The same results were obtained in Acinetobacter sp. QNA2-treated alfalfa plants grown in the soil plus 50-mg kg−1 sodium arsenate. These results demonstrated that arsenic-resistant endophytic bacteria are potential candidates to enhance plant-growth promotion in As contamination soils. Characterization of bacterial endophytes with plant growth potential can help us apply them to improve plant yield under stress conditions.

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Isolation and characterization of plant growth-promoting endophytic bacteria of wild legumes growing on sandy soils of Binh Thuan province, Vietnam

World Journal of Advanced Research and Reviews ◽

10.30574/wjarr.2021.10.3.0274 ◽

2021 ◽

Vol 10 (3) ◽

pp. 246-254

Author(s):

Dang Thi Ngoc Thanh ◽

Pham Thi Thu Ly ◽

Pham Thi Nga ◽

Pham Van Ngot

Keyword(s):

Nitrogen Fixation ◽

Plant Growth ◽

Endophytic Bacteria ◽

Phosphate Solubilization ◽

Sandy Soils ◽

Legume Species ◽

Bacterial Isolates ◽

Isolation And Characterization ◽

Plant Growth Promoting ◽

Growth Promoting

The roots of two legume species (Tephrosia purpurea and Tephrosia villosa) that grew wild on dry sandy soils of Binh Thuan province were sources for isolating plant growth-promoting endophytic bacteria. Semi-solid LGI medium was used for the isolation of nitrogen-fixing bacteria from root extracts. All bacterial isolates isolates were evaluated for their ability to solubilize calcium orthophosphate on solid NBRIP medium and their ability to produce IAA in Burk's liquid medium supplemented with 100 mg/L tryptophan. The possibilities of nitrogen fixation, phosphate solubilization and IAA synthesis were all quantitative examined by colorimetric method. Twenty-two bacterial isolates of T. purpurea and 18 isolates of T. villosa were capable of nitrogen fixation in the range of 1.94 to 2.81 mg/L NH4+, whereas only 18 isolates of T. purpurea and 16 isolates of T. villosa showed phosphate solubilization in the range of 12.30 – 48.90 mg/L P2O5, and IAA production in the range of 0.38 – 12.72 mg/L. Sixteen outstanding bacterial isolates of the two legume species were identified by MALDI-TOF technique. The results showed that 13 isolates had high similarity with five bacterial genera including Klebsiella, Cronobacter, Enterobacter, Burkholderia, and Bacillus with score values in the range of 2.070 – 2.411.

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