Screening of Plant Growth–Promoting Rhizobacteria from Maize (Zea Mays) and Wheat (Triticum Aestivum) (original) (raw)
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European Journal of Biological Research, 2018
Plant Growth-Promoting Rhizobacteria (PGPR) inhabiting the area around the plant roots or in plant tissues and stimulate plant growth directly or indirectly. Synthesis of the phytohormone auxin indole-3-acetic acid (IAA) is one of the direct effects of PGPR on plant growth. This study aimed to isolate and screen IAA producing bacteria from soil and study the impacts of the alkalinity and salinity on IAA production and total antioxidant activity of the highly IAA producing strain. From the fifteen isolates tested, six were selected as efficient IAA producer, from which one isolate was highly IAA producer. The highly producing isolate was identified based on molecular characteristics using 16S rRNA. The sequence analysis showed 99% similarity with Bacillus subtilis from GenBank data base. The strain yielded IAA in a wide range of pH (5-9), giving its maximum IAA production at pH 8. High IAA concentration was also observed in the presence of 0.5% and 1% NaCl in comparison with control ...
Journal of Agricultural Chemistry and Biotechnology
The present work aims to surveying plant growth-promoting rhizobacteria (PGPR) for their ability to produce the plant growth regulator indole-3-acetic acid (IAA). One hundred and forty eight isolates from such bacteria were obtained representing the rhizosphere and rhizoplane of maize, wheat, barley, sorghum and sugar cane form different locations in Egypt (Giza, Faioum, Kafer El-Sheikh and Ismailia). Twenty isolates were selected according to their ability to produce high amount of microbial IAA. The determination of IAA was carried out by calorimetric method and chromatographic analysis (GLC). These isolates were grown on minimal medium with different carbon sources. Glucose was the best carbon source for growing the most isolates and the presence of tryptophan was necessary for production of IAA. Seven isolates which produce IAA more than others were purified and identified applying both conventional morphological, cultural, biochemical methods and API microtube systems. Accordingly, they were placed under the species of Klebsieilla pneumomiae, Azospirillum spp. Enterobacter cloacae, and Pseudomonas fluorescens.
Isolation and Characterization of Plant Growth-Promoting Bacteria from Different Rhizospheric Soils
THE JOURNAL OF MICROBIOLOGY AND MOLECULAR GENETICS
The production of indole acetic acid (IAA) is a significant property of rhizospheric bacteria to stimulate and promote plant growth. In this investigation, indole acetic acid-producing bacteria from the rhizosphere of five distinct plants (Wheat, Gulchen, Rose, Lady Finger, and Bouginvella) were isolated and characterized. Bacterial strains were isolated and identified by morphological characterization. Out of 30 bacterial isolates, 5 isolates were selected as efficient producers of Indole acetic acid. These selected bacterial isolates were subjected to several biochemical tests for identification at the genus level. After the determination of bacterial genus, antibiotic sensitivity test was performed to check the resistance pattern of each bacterial isolate against antibiotics. Selected bacterial isolates were characterized by using molecular techniques. DNA of five bacterial isolates was extracted by WizPrepTMg DNA mini kit and amplification of 16S rRNA gene was done by PCR. Ampli...
Journal of University of Shanghai for Science and Technology, 2021
Indole acetic acid (IAA) production is a major property of rhizosphere bacteria that stimulates and facilitates plant growth. The present work deals with the isolation, characterization, and identification of indole acetic acid-producing bacteria from the rhizospheric soil. Out of four organisms isolated from serial dilution, Sample-2 confirmed thick bands of IAA production by TLC analysis. 16s rRNA analysis showed the isolated organism was found to be Pseudomonas fluorescence with a similarity of 88%. The isolated organism treat plants showed increased shoot and root length in plant growth analysis. In conclusion, the isolated IAA-producing bacteria can be used as efficient biofertilizer inoculants to promote plant growth.
Plant Growth Promoting Rhizobacteria (PGPB) is considered to promote plant growth directly or indirectly. PGPB can exhibit a variety of characteristics responsible for influencing plant growth. The common traits include production of plant growth regulators (auxin, gibberellin, ethylene etc.), siderophores, HCN and antibiotics. Indole acetic acid (IAA) is one of the most physiologically active auxins. IAA is a common product of L-tryptophan metabolism by several microorganisms including PGPR. To study the effect of IAA producing rhizospheric isolates on plant growth, cup assay was performed. Vigna mungo (black grams) seeds were used for seed coating. The seeds were surface sterilized by immersing in 95% ethanol for 30 sec and mercury chloride (0.2%) for 3 min. Then further to remove traces of mercury chloride, the disinfected seeds were washed 5 times by sterile distilled water. 0.1 ml of overnight grown culture was applied on seed surface for seed coating. Seeds were dried and sowed into sterile plate until the seeds start germinating. The uncoated seeds were used as control. The germinated seeds were transferred to pots and grown for 7 days. The growth was checked by measuring their root length, shoot length and the number of leaves. The IAA produced by rhizospheric bacteria displayed appreciable activity. The shoot length, root length and the number of leaves obtained were higher compared to control. It is concluded that presence of such growth promoting rhizoflora accountable for the beneficial effects on Vigna mungo growth and yield.
Effect of different fertilization treatments on indole-3-acetic acid producing bacteria in soil
Journal of Soils and Sediments, 2011
Purpose Soil microorganisms directly affect the growth of plants. Especially, plant growth-promoting rhizobacteria (PGPR) play an important role in plant growth. There are many studies about the effects of different fertilization treatments on soil microbial community structure; however, the effects on PGPR, including indole-3-acetic acid (IAA)-producing bacteria have not been previously reported. The objective of this study is to determine the effects of different types of fertilizers on IAA-producing bacteria. Materials and methods The field trial was completed in the North China with a winter wheat and summer corn rotation system. IAA-producing bacteria were screened from soil treated with different fertilizer (non-nitrogen fertilizer (CK), controlled-release fertilizer (CR), chemical fertilizer (CF), and organic fertilizer (OF)) which was established in September 2005. Quantity of IAA produced by bacteria was determined by spectrophotometer. IAA-producing bacteria were identified based on 16S rDNA sequence. Community structures and phylogenetic relationships of IAA-producing bacteria were analyzed by online Basic Local Alignment Search Tool search engine, biosoftware of DNAMAN and Molecular Evolutionary Genetics Analysis. Results and discussion Compared with CK treatment, CF and CR treatment increased soil pH values, while OF treatment decreased pH. The three types of fertilizers all increased soil organic carbon and total nitrogen, with OF treatment causing the significant increase. Soils treated with OF or CR fertilizer could significantly increase the number of culturable bacteria compared with CF or CK treatment. Fifty-three IAA-producing bacteria (14 strains from CK, nine from CF, eight from CR, and 22 from OF) were identified based on 16S rDNA sequence. The Shannon–Weiner index of IAA-producing bacteria isolated from CK and OF (2.06 and 2.45, respectively) was significantly higher than those from CF and CR (0.50 and 0.95, respectively). Arthrobacter sp. was the most prevalent group of IAA-producing bacteria. Conclusions The fertilizers increased soil organic carbon and total nitrogen, particularly the organic fertilizers. Controlled-release fertilizers and organic fertilizers can promote growth of soil-culturable bacteria and IAA-producing bacteria. These may be reasons why organic fertilizers and controlled-release fertilizers can promote crop growth. Different fertilization treatments affected IAA yield mainly through modifying the quantities of microorganisms, rather than changing the IAA-producing ability of the same microorganisms. Pedobacter sp. which can produce IAA has not been described previously.
Journal of Pure and Applied Microbiology
Plant growth-promoting rhizobacteria (PGPR) have proved to be an effective solution for enhancing growth of various plant species. Five different bacterial isolates extracted from rhizosphere soil were extensively studied for the production of indole acetic acid (IAA) and among those Bacillus safensis YKS2 strain was found to produce substantial quantities of IAA. B. safensis YKS2 strain was characterized and submitted to National Centre for Biotechnology Information (NCBI) (Gen Bank No. MH539636). Optimization of IAA production with varying pH and temperature revealed that IAA production was maximum at pH 7 and at a temperature of 37°C. The production of IAA was confirmed and quantified by Fourier-transform infrared spectroscopy (FTIR), Thin-layer chromatography (TLC), Gas chromatography-mass spectrometry (GC-MS). The PGPR inoculum showed significant (p<0.05) shoot increase (60.00 – 89.00%) and root increase (30.00 – 90.00%) relative to the controls in Vigna radiata. This study ...
Evaluation of Plant Growth Promoting Activity of Rhizosphere Bacteria of Different Crop Plants
Plant growth promoting rhizobacteria (PGPR) are good sources of nourishment to soil and hence a potential alternative to chemical fertilizers. In the study, a total of 12 rhizobacterial isolates, designated as SI1 -SI12 were assayed for their plant growth promoting activity. Using available standardized protocols the phosphate solubilisation and nitrogen fixation capabilities of the bacterial isolates were determined. Indole acetic acid (IAA) production capability of all the isolates was observed, among which two of the isolates SI-2 and SI-9 were noted to produce IAA in considerable amounts. These PGPR are thus found to be a promising source of bio fertilizers, detailed experimental study of which is to be accomplished in future.
Engineering Journal, 2012
18 rhizobacteria were isolated from various rhizospheric soils in Mandalay region, Myanmar and some of their biochemical characteristics were studied. Among them, 4 isolates belonged to Bacillus spp. and another 5 strains were recognized as Serratia spp. All 18 isolates were screened for indole-3-acetic acid (IAA) production and quantitative determination of IAA was done for all strains by UV-Vis spectrophotometer with 2 days interval during 10 days incubation. All isolates had different optimum IAA production periods and strain R1 was the best IAA producer strain with 121.1 ppm. It was observed that Bacillus spp. produced IAA ranging from 53.1 ppm to 71.1 ppm optimally and Serratia spp. were regarded as poor IAA producers. Among these 18 strains, the best four IAA producers (R1, R3, R5, R8) were selected for further study on maize plant and their activities of nitrogen fixation were also detected by plate screening method. Seed germination rate was studied with eight types of treatment and the treatments with isolates did not show significant effects on seed germination rate. At 20 th day after sowing, dry root weight and fresh root weight, root length, number of adventitious roots, dry shoot weight and fresh shoot weight and shoot height were analyzed. In pot trial experiment, treatment R1 significantly increased the fresh shoot weight, shoot height and dry shoot weight whereas treatment R3 significantly increased fresh root weight, root length, dry root weight and number of adventitious roots and all treatments with bacterial isolates showed plant growth promotion than the control systems.