Phosphate-solubilization mechanism and in vitro plant growth promotion activity mediated by Pantoea eucalypti isolated from Lotus tenuis rhizosphere in the Salado River Basin (Argentina)

2011 ◽  
Vol 110 (5) ◽  
pp. 1151-1165 ◽  
Author(s):  
L.N. Castagno ◽  
M.J. Estrella ◽  
A.I. Sannazzaro ◽  
A.E. Grassano ◽  
O.A. Ruiz
2012 ◽  
pp. 525-532 ◽  
Author(s):  
S. Velivelli ◽  
E. O'Herlihy ◽  
B. Janczura ◽  
B. Doyle Prestwich ◽  
J. Ghyselinck ◽  
...  

2016 ◽  
Vol 4 (1) ◽  
pp. 27 ◽  
Author(s):  
Edi Husen

Fourteen isolates of soil bacteria, including two known plant growth promoting rhizobacteria (PGPR) strains, Azotobacter vinelandii Mac 259 and Bacillus cereus UW 85, were tested in vitro. Parameters assessed were indoleacetic acid (IAA) production, phosphate solubilization, dinitrogen fixation, and siderophore (Fe-III chelating agent) production. IAA production was assayed colorimetrically using ferric chlorideperchloric acid reagent. Phosphate-solubilization and siderophore production were tested qualitatively by plating the bacteria in Pikovskaya and chrome azurol S agar, respectively. The ability to fix dinitrogen was measured based on nitrogenase activity of the bacteria by gas chromatography. The results showed that twelve isolates produced IAA, ranged from 2.09 to 33.28 µmol ml-1. The ability to solubilize precipitated phosphate was positively exhibited by four isolates (BS 58, BTS, TCaR 61, and BTCaRe 65). Seven isolates including Mac 259 positively produced siderophore. None of the isolates showed nitrogenase activity. Only one isolate (TS 3) did not exhibit any of the traits tested. Isolate TCeRe 60 and reference strain Mac 259 were found to have IAA- and siderophore-producing traits. Four P-solubilizing bacteria (BS 58, BTS, TCaR 61, and BTCaRe 65) were also IAA- and siderophore-producing bacteria. Potential use of these PGPR isolates needs further test in enhancing plant growth.


2017 ◽  
Vol 9 (3) ◽  
pp. 1310-1316
Author(s):  
Gurjot Kaur ◽  
Poonam Sharma ◽  
Deepika Chhabra ◽  
Kailash Chand ◽  
Gurjit Singh Mangat

The present investigation was carried out to exploit bacterial endophytes associated with root and leaf tissue of rice plant for plant growth promotion (PGP) and colonization study in vitro. Total 10 endophytic bacterial isolates (Pseudomonas sp.) were evaluate for PGP traits like P solubilization, production of Indole acetic acid (IAA), siderophore, ACC deaminase, protease, cellulase, fluorescent pigment, urease and denitrification activity. Out of 10 endophytic bacteria 30 %, 60 %, 20 %, 70 %, 10 % and 10 % were positive for siderophore, protease, cellulase, fluorescent pigment, urease and denitrification respectively. Maximum IAA production was recorded with isolate LRBLE7 (18.8 μgml-1) followed by LRBRE4 (16.0 μgml-1) and maximum P-solubilization was recorded with isolate LRBRE4 (5.8 mg 100 ml-1) followed by LRBLE7 (4.4 mg 100 ml-1). ACC deaminase production was recorded with isolate LRBLE6 (O.D=0.352 nm) followed by LRBRE5 (O.D=0.324nm). Three potential isolates (LRBRE4, LRBRE6 and LRBLE7) were selected on the basis of multiple PGP traits and were subjected to colonization study of rice seedling in vitro. Potential bacterial isolates can be exploited for improving growth and productivity in rice under sustainable management system.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Francesca Mapelli ◽  
Ramona Marasco ◽  
Eleonora Rolli ◽  
Marta Barbato ◽  
Hanene Cherif ◽  
...  

Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres ofSalicorniaplants and bulk soils were collected fromSebkhetandChotthypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated withSalicorniaroot system. A large collection of 475 halophilic and halotolerant bacteria was established fromSalicorniarhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP) features. TwentyHalomonasstrains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activitiesin vitroat 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using agfp-labelled strain it was possible to demonstrate thatHalomonasis capable of successfully colonisingSalicorniaroots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.


2015 ◽  
Vol 9 (3) ◽  
pp. 24-37 ◽  
Author(s):  
Mohammed Faisal Ansari ◽  
Devayani R. Tipre ◽  
Shailesh R. Dave

Organic farming is gaining popularity where bio-inoculants could play a key role in promoting the growth of plants. The liquid biofertilizers concept is new to farmers and developed recently. Lots of liquid biofertilizers formulations and field efficiency were shown in the past by various researchers, but the plant growth promoting (PGP) efficiency of the liquid biofertilizers isolates were not reported till date. In the present work 6 different commercially available liquid biofertilizers were used to isolate the organism. These isolated cultures were used to study their PGP efficiency with respect to phosphate solubilization and production of EPS, IAA, siderophore, ammonia, chitinase, ACC-deaminase and HCN. The phosphate solubilization was shown up to 303 g/ml by APS isolate. EPS production was shown by using different C sources and production up to 24 g/l was shown by studied isolated. Most of the organisms studied were able to produce IAA and highest production was shown up to 20 g/ml. More than 65% studied isolates showed siderophore and ACC-deaminase production. The present study shows that the commercial liquid biofertilizer isolates possess multiple traits of plant growth promotion. DOI: http://dx.doi.org/10.3126/ijls.v9i3.12463   International Journal of Life Sciences 9 (3): 2015; 24-37


2021 ◽  
Vol 11 ◽  
Author(s):  
Francisco Massot ◽  
Panagiotis Gkorezis ◽  
Jonathan Van Hamme ◽  
Damian Marino ◽  
Bojana Spirovic Trifunovic ◽  
...  

The large-scale use of the herbicide glyphosate leads to growing ecotoxicological and human health concerns. Microbe-assisted phytoremediation arises as a good option to remove, contain, or degrade glyphosate from soils and waterbodies, and thus avoid further spreading to non-target areas. To achieve this, availability of plant-colonizing, glyphosate-tolerant and -degrading strains is required and at the same time, it must be linked to plant-microorganism interaction studies focusing on a substantive ability to colonize the roots and degrade or transform the herbicide. In this work, we isolated bacteria from a chronically glyphosate-exposed site in Argentina, evaluated their glyphosate tolerance using the minimum inhibitory concentration assay, their in vitro degradation potential, their plant growth-promotion traits, and performed whole genome sequencing to gain insight into the application of a phytoremediation strategy to remediate glyphosate contaminated agronomic soils. Twenty-four soil and root-associated bacterial strains were isolated. Sixteen could grow using glyphosate as the sole source of phosphorous. As shown in MIC assay, some strains tolerated up to 10000 mg kg–1 of glyphosate. Most of them also demonstrated a diverse spectrum of in vitro plant growth-promotion traits, confirmed in their genome sequences. Two representative isolates were studied for their root colonization. An isolate of Ochrobactrum haematophilum exhibited different colonization patterns in the rhizoplane compared to an isolate of Rhizobium sp. Both strains were able to metabolize almost 50% of the original glyphosate concentration of 50 mg l–1 in 9 days. In a microcosms experiment with Lotus corniculatus L, O. haematophilum performed better than Rhizobium, with 97% of glyphosate transformed after 20 days. The results suggest that L. corniculatus in combination with to O. haematophilum can be adopted for phytoremediation of glyphosate on agricultural soils. An effective strategy is presented of linking the experimental data from the isolation of tolerant bacteria with performing plant-bacteria interaction tests to demonstrate positive effects on the removal of glyphosate from soils.


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