Characterization of free nitrogen fixing bacteria of the genus Azotobacter in organic vegetable-grown Colombian soils

Plant biostimulants can enhance crop nutrition status, stress tolerance, yield and quality in environment-friendly manner. The aim of this study was to determine the effect of an algae and bacteria preparations on the yield and nutritional parameters of leaf and romaine lettuce cultivated for spring and summer crop. The application of a combined biostimulant consisting of plant growth-promoting bacteria (Bacillus licheniformis, Bacillus megatherium, Azotobacter sp., Azospirillum sp., and Herbaspirillum sp.) and fresh water algae (Chlorella vulgaris) was done by watering the lettuce every 14 days, and a determination of the fresh weight, total antioxidant capacity, and total carotenoids content was performed. The result revealed that the application of bacterial-algal preparation significantly affected the plant weight of both romaine and leaf lettuce in spring and summer seasons. The highest increase in the weight of romaine lettuce reached 18.9% in the spring crop, while in the case of leaf lettuce, biostimulant treatment led to a 22.7% higher weight in the summer crop. Total antioxidant capacity and total carotenoids content showed increased values in the summer crop of romaine lettuce, while for the leaf lettuce there were no differences between treatments. Therefore, the positive effect of bacterial-algal treatment on lettuce yield, total antioxidant capacity and total carotenoids confirm that it could be applied for improving romaine lettuce yield quality and quantity, especially in stress, summer conditions.

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“…and Azospirillum sp. fix nitrogen and produce siderophores (Steenhoudt and Vanderleyden, 2000;Jiménez et al, 2011).…”

Section: Biological Materialsmentioning

confidence: 99%

Effect of Bacterial-algal Biostimulant on the Yield and Internal Quality of Lettuce (Lactuca sativa L.) Produced for Spring and Summer Crop

Kopta

Pavlíková

Sękara

et al. 2018

Not Bot Horti Agrobo

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“…Growth in the presence of 0.01% malachite green was tested (Franke et al 1999). Nitrogen fixation, phosphate solubilization and potassium solubilization capacity of strain qzr14 were assessed using selective mediums (Jiménez et al 2011;Nautiyal 1999). P-solubilization was further determined using the Mo-blue method (Chen et al 2006).…”

Section: Microorganismsmentioning

confidence: 99%

The persistence and performance of phosphate-solubilizing Gluconacetobacter liquefaciens qzr14 in a cucumber soil

Wang

Yin

et al. 2017

3 Biotech

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The persistence and performance of plant growth-promoting microorganisms (PGPMs) in soil are considered critical features for effectiveness, yet they are poorly understood. Here, we investigated the colonization and activity of a new PGPM, phosphate-solubilizing Gluconacetobacter liquefaciens qzr14, in a pot culture experiment using cucumber as test crop for 20 days. The number of G. liquefaciens and bacterial diversity in the rhizosphere and bulk soil were monitored by real-time PCR and DGGE, respectively. Soil phosphorus and cucumber biomass were also examined. G. liquefaciens qzr14 effectively colonized the rhizosphere soil (bacterial density ranging from 2.70 9 10 8 to 1.18 9 10 9 copies per gram dry soil). G. liquefaciens qzr14 inoculation had significantly positive effects on bacterial diversity (BD) of the rhizosphere and bulk soil and the ratio of soluble phosphorus to total phosphorus (SP/TP). The number of G. liquefaciens in the rhizosphere soil was significantly related to SP/TP and the BD of the rhizosphere and bulk soil. BD in rhizosphere soil was significantly related to SP/TP and BD in bulk soil. Based on the results of correlation analysis, we inferred that the introduced G. liquefaciens qzr14 effectively colonized the rhizosphere of cucumber, and then expanded its bacterial community by solubilizing soil phosphorus. The expanded bacterial communities might promote cucumber growth by some new functions.

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“…The soil pH was measured according to the protocol of Jimenez et al (2011) and pH tolerance was carried out at different pH ranges. Different ranges of pH (5.5 to 9.5) Burk's media were prepared by adjusting the media pH (NaOH or HCL); one set with pH 7.0 were maintained as control.…”

Section: Ph Tolerancementioning

confidence: 99%

“…25µl PCR reaction mixture contains 15.3µl of autoclaved distilled water, 2µl of purified DNA template, 2.5µl 1X Taq buffer, 2µl of MgCl2, 2µl of deoxyribonucleotide triphosphate mixture, 1µl of each primer, 0.2µl of Taq DNA polymerase (Genei). PCR amplification reaction was run in a thermocycler with following conditions (35 cycles consisting of 95º C for 1 min, 55º C for 1 min, 72º C for 1 min, and final extension at 72 º C for 5 min) were done (Rajeswari and Kasthuri, 2009;Jimenez et al, 2011). The amplified were checked in 1.5% agarose gel for further confirmation.…”

Section: Dna Extraction and Amplification Of Nif Genementioning

confidence: 99%

“…PGPR can helps to replace chemical fertilizer nitrogen for the sustainable cultivation by fixing the atmospheric N2 and producing growth promoting substances (Ahmad et al 2005). Many species of Pseudomonas, Bacillus and Azotobacter can grow and survive at extreme environmental conditions (Jimenez et al 2011). Among them, the genus Azotobacter are common nitrogen fixing bacterium found in agricultural soils playing different beneficial roles by secreting vitamins, amino acids, sidephores and auxins (Aquilanti et al, 2004;Sharma et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

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Impact of Pesticides on PGPR Activity of Azotobacter sp. Isolated from Pesticide Flooded Paddy Soils

Chennappa¹,

Adkar-Purushothama²,

Naik³

et al. 2014

GJAS

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Azotobacter strains were isolated from paddy soils by serial dilution agar plate method.The colonies were glistening; smooth, slimy, brown to black in morphology on Jenson's N-free agar plates and the cells were Gram-negative bacteria. Biochemically, they were positive for indole production, citrate, catalase and Voges Proskauer test. Further, Nif gene sequence results revealed the presence of seven Azotobacter species. The effect of 1, 3 and 5% pesticides concentration viz., pendimethalin, chloropyrifos, glyphosate and phorate on nitrogen fixation, indole acetic acid, gibberllic acid, phosphate solubilization and bioassay of Azotobacter sp. were studied. Among all the species, GVT-1 strain was found to fix nitrogen at a maximum of 30µgN2 ml -1 day -1 , produced highest quantity gibberllic acid (10µg25ml -1 ) and able to solubilize the phosphate at the rate of 9.8cm by forming the halo zone which was supplemented with 5% phorate. Similarly, GVT-1 strain produced a highest amount of indole acetic acid (31.8µgml -1 ) in 5% pendimethalin. Further bioassay activities of GVT-1 strain found efficient in increasing the root, shoot length and vigor of the plant. From these results it is clear that the Azotobacter sp. not only produces plant growth promoting substances but is also resistant to different pesticides and is not affected by the bacterial activity.

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Characterization of free nitrogen fixing bacteria of the genus Azotobacter in organic vegetable-grown Colombian soils

Cited by 74 publications

References 27 publications

Effect of Bacterial-algal Biostimulant on the Yield and Internal Quality of Lettuce (Lactuca sativa L.) Produced for Spring and Summer Crop

Effect of Bacterial-algal Biostimulant on the Yield and Internal Quality of Lettuce (Lactuca sativa L.) Produced for Spring and Summer Crop

The persistence and performance of phosphate-solubilizing Gluconacetobacter liquefaciens qzr14 in a cucumber soil

Impact of Pesticides on PGPR Activity of Azotobacter sp. Isolated from Pesticide Flooded Paddy Soils

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