Analysis of phytohormones and phosphate solubilization in Photorhabdus spp.

2013 ◽  
Vol 22 (S1) ◽  
pp. 25-31 ◽  
Author(s):  
Ihsan Ullah ◽  
Abdur Rahim Khan ◽  
Gun-Seok Park ◽  
Jong-Hui Lim ◽  
Muhammad Waqas ◽  
...  
Author(s):  
Zaid Raad Abbas ◽  
Aqeel Mohammed Majeed Al-Ezee ◽  
Sawsan H

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luz K. Medina-Cordoba ◽  
Aroon T. Chande ◽  
Lavanya Rishishwar ◽  
Leonard W. Mayer ◽  
Lina C. Valderrama-Aguirre ◽  
...  

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.


2020 ◽  
Vol 4 (1) ◽  
pp. 58-69
Author(s):  
Babatide Olufemi Oladapo ◽  
Esther Aanuoluwa Ekundayo ◽  
Mariam Olukemi Mokoolu ◽  
Fatuyi Olanipekun Ekundayo

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.


2014 ◽  
Vol 8 (27) ◽  
pp. 2616-2623 ◽  
Author(s):  
Paixo Resende Mara ◽  
Cristina Mendona Cardoso Jakoby Isabel ◽  
Carlos Ramos dos Santos Luiz ◽  
Antnio Soares Marcos ◽  
Dionsio Pereira Flvia ◽  
...  

2020 ◽  
Vol 1 (2) ◽  
pp. 37-51
Author(s):  
C. E. Oshoma ◽  
S. O. Nwodo ◽  
I. S. Obuekwe

The processing of cassava into value-added products is associated with discharge of effluents which contain substances that have adverse effect on the environment. Remediative activity of indigenous bacteria can be stimulated by supplementing effluents with phosphorus. Rock phosphate (RP) solubilization and enzymatic activities from bacteria on the cassava mill effluents (CME) contaminated soil was investigated. Soil mixed with varying concentrations of CME (0, 100, 200, 300, 400, 500 and 600 ml) and 10 g of RP were analyzed on days 0 and 16. Parameters analyzed were changes in pH, heterotrophic bacteria load, phosphate-solubilizing bacteria load, available phosphorus, acid phosphatase, cellulase and urease concentrations. The results showed that the medium containing 400 ml CME contaminated soil had the highest phosphate-solubilizing bacteria load (12.60 ± 2.08 x 106 cfu/ml), available phosphorus (126.00 ± 4.08 mg/kg), acid phosphatase (9.54 ± 0.51 mgN/g/min), cellulase (15.24 ± 0.81 mg/g/6h) and urease concentration (2.15±0.22 mg/g/2h). The control had the lowest phosphate-solubilizing bacteria load and enzymatic activity. Biostimulation of indigenous bacteria to enhance the degradation of cassava mill effluent-contaminated soil, using rock phosphate, showed promising results. This implies that rock phosphate solubilization by indigenous bacteria in CME-contaminated soils could be important for the remediation and reclamation of contaminated lands.


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