Characterization of plant growth promoting rhizobacteria isolated from polluted soils and containing 1-aminocyclopropane-1-carboxylate deaminase

2001 ◽  
Vol 47 (7) ◽  
pp. 642-652 ◽  
Author(s):  
Andrei A Belimov ◽  
Vera I Safronova ◽  
Tatyana A Sergeyeva ◽  
Tatyana N Egorova ◽  
Victoria A Matveyeva ◽  
...  

Fifteen bacterial strains containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase were isolated from the rhizoplane of pea (Pisum sativum L.) and Indian mustard (Brassica juncea L.) grown in different soils and a long-standing sewage sludge contaminated with heavy metals. The isolated strains were characterized and assigned to various genera and species, such as Pseudomonas brassicacearum, Pseudomonas marginalis, Pseudomonas oryzihabitans, Pseudomonas putida, Pseudomonas sp., Alcaligenes xylosoxidans, Alcaligenes sp., Variovorax paradoxus, Bacillus pumilus, and Rhodococcus sp. by determination of 16S rRNA gene sequences. The root elongation of Indian mustard and rape (Brassica napus var. oleifera L.) germinating seedlings was stimulated by inoculation with 8 and 13 isolated strains, respectively. The bacteria were tolerant to cadmium toxicity and stimulated root elongation of rape seedlings in the presence of 300 µM CdCl2 in the nutrient solution. The effect of ACC-utilising bacteria on root elongation correlated with the impact of aminoethoxyvinylglycine and silver ions, chemical inhibitors of ethylene biosynthesis. A significant improvement in the growth of rape caused by inoculation with certain selected strains was also observed in pot experiments, when the plants were cultivated in cadmium-supplemented soil. The biomass of pea cv. Sparkle and its ethylene sensitive mutant E2 (sym5), in particular, was increased through inoculation with certain strains of ACC-utilising bacteria in pot experiments in quartz sand culture. The beneficial effect of the bacteria on plant growth varied significantly depending on individual bacterial strains, plant genotype, and growth conditions. The results suggest that plant growth promoting rhizobacteria containing ACC deaminase are present in various soils and offer promise as a bacterial inoculum for improvement of plant growth, particularly under unfavourable environmental conditions.Key words: ACC deaminase, cadmium, ethylene, Indian mustard, pea, phytoremediation, rape, rhizobacteria.

Author(s):  
Shamal S. Kumar ◽  
Ananta G. Mahale ◽  
Md. Mifta Faizullah ◽  
J. Radha Krishna ◽  
Tharun K. Channa

Water scarcity is known as a major stumbling block towards crop development and its output all over the world. Certain free-living bacterial strains have been found near the plant root zones which have shown to improve resistance of plants towards water stress. Despite availability of basic nutrients, drought an abiotic factor substantially inhibits growth, development and yield of crops by causing an increase in ethylene levels. It is a good idea to incorporate the use of a management tool which is the utilization of plant growth-promoting rhizobacteria to help several crops manage drought conditions. Drought stress in crops can be alleviated by reducing ethylene synthesis, exopolysaccharide, osmoregulation, Indole-3-acetic acid and aggregation with the ACC deaminase-containing plant growth-promoting rhizobacteria. Inoculating pathogens like root rot (Macrophomina phaseolina) affected plant with Pseudomonas fluorescens strain TDK1 with ACC deaminase function improves drought stress. Using plant growth-promoting rhizobacteria to mitigate the negative imbibes of drought in most crops is a good idea. Several studies have been carried out on plant growth-promoting rhizobacteria, as its inoculation not only manages drought related conditions but increases root hair growth and lateral root, which assist in increased water and nutrient uptake. It limits ethylene supply, alternatively increases plant root growth by hydrolyzing 1-aminocyclopropane-1-carboxylic acid (ACC). This review will give us a perspective on the importance of plant growth-promoting rhizobacteria, as it is one of the efficient tools that helps manage drought stress on several crops.


1995 ◽  
Vol 41 (6) ◽  
pp. 533-536 ◽  
Author(s):  
Bernard R. Glick ◽  
Damir M. Karaturovíc ◽  
Peter C. Newell

A rapid and novel procedure for the isolation of plant growth promoting rhizobacteria (PGPR) is described. This method entails screening soil bacteria for the ability to utilize the compound 1-aminocyclopropane-1-carboxylate (ACC) as a sole N source, a trait that is a consequence of the presence of the activity of the enzyme ACC deaminase. This trait appears to be limited to soil bacteria that are also capable of stimulating plant growth. Seven different soil samples from two geographically disparate locations were found to contain pseudomonads that were able to to utilize ACC as a N source. Each of the seven strains was shown, by the ability of the bacterium to promote canola seedling root elongation under gnotobiotic conditions, to be a PGPR. The method described here may be used to replace the otherwise slow and tedious process of testing individual bacterial strains for their ability to promote plant growth, thereby significantly speeding up the process of finding new PGPR.Key words: plant growth promoting rhizobacteria, PGPR, 1-aminocyclopropane-1-carboxylate, ACC, ACC deaminase, bacterial fertilizer, soil bacteria.


1994 ◽  
Vol 40 (11) ◽  
pp. 911-915 ◽  
Author(s):  
Bernard R. Glick ◽  
Christian B. Jacobson ◽  
Melinda M. K. Schwarze ◽  
J. J. Pasternak

The plant growth promoting rhizobacterium Pseudomonas putida GR12-2 was mutagenized with nitrosoguanidine and three separate mutants that were unable to utilize 1-aminocyclopropane-1-carboxylic acid (ACC) as a sole nitrogen source were selected. These mutants are devoid of the ACC deaminase activity that is present in wild-type P. putida GR12-2 cells. Only wild-type cells, but not any of the ACC deaminase mutants, promoted root elongation of developing canola seedlings under gnotobiotic conditions. These results are interpreted in terms of a model in which P. putida GR12-2 promotes root elongation by binding to germinating seeds and sequesters and hydrolyzes some of the unbound ACC, thereby lowering the level of ACC and hence the endogenous ethylene concentration, allowing the roots to grow longer.Key words: 1-aminocyclopropane-1-carboxylate, ACC, plant growth promoting rhizobacteria, PGPR, ACC deaminase, bacterial fertilizer.


2012 ◽  
Vol 12 (51) ◽  
pp. 6170-6185
Author(s):  
A Karnwal ◽  

Plant growth-promoting rhizobacteria (PGPR) are free-living soil-borne bacteria that colonize the rhizosphere and have great importance in governing the functional property of terrestrial ecosystems. In this study, rhizospheric bacteria were isolated from maize and wheat and screened for their plant growth promoting activities. These isolates were identified as Pseudomonas , Bacillus , Azospirillum and Azotobacter species. All isolates were tested for their indole acetic acid (IAA) production ability. All isolates produce the varying amount s o f IAA ranging from 0.6- 2.7 μg/ml. The highest concentration of IAA was produced by bacterial strain Bacillus subtilis AK31. A series of growth pouch and pot experiments were conducted to study the effect of bacterial inoculants on the growth of maize and wheat. It was concluded that IAA plays a key role i n the growth promotion of roots in maize and wheat in growth pouch study. In maize, isolate AK1, AK21, AK31 and AK8 showed high indole acetic acid (6.86, 7.11, 7.11 and 7.36 pmol/ml, respectively) and root elongation activity ( 4.10, 5.00, 5.00 and 3.80 cm, respectively) after 96h of growth. In wheat, bacterial strains AK31, AK2, AK14, AK32 and AK15 showed high IAA ( 6.59, 5.66, 5.35, 7.53 and 5.66 pmol/ml, respectively) and root elongation ( 6.07, 4.00, 5.20, 6.90 and 5.20 cm, respectively) activity after 96h of growth. In pot experiments, Bacillus sp. AK21, Bacillus subtilis AK31, Azotobacter diazotrophicus AK14, Microbacterium sp. AK19 and Pseudomonas fluorescens AK32 showed effective results in term s of increase in root and shoot dry weight in maize (123, 130, 121, 120, 124g and 116, 126, 116, 114, 120g/pot, respectively) and wheat (130, 135, 125, 118, 140g and 105, 106, 110, 102, 110g/pot, respectively), in comparison to controls of maize and wheat crops. Thus, it might be concluded that PGPR strains AK21, AK31, AK14, AK19 and AK32 could be used as crop- enhancer and bio- fertilizer for production of maize and wheat .


2013 ◽  
Vol 1 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Umesh P. Shrivastava ◽  
Ashok Kumar

A total of nine strains of plant growth promoting rhizobacteria were analyzed for ACC deaminase activity, where highest ACC deaminase activity was found in Klebsiella sp strain ECI-10A (539.1 nmol α-keto butyrate/ mg protein/ h) and lowest in Microbacterium sp strain ECI-12A (122.0 nmol α-keto butyrate/ mg protein/ h). Although Microbacterium sp strain ECI-12A showed lowest level of ACC deaminase activity, but, the species of Microbacterium isolated from rhizosphere is the first report. Microbacterium sp strain ECI-12A was also analyzed under varying conditions of time, amount of 1-Aminocyclopropane-1- carboxylate (ACC), and temperature for optimization of the ACC deaminase activity. The optimum activity was recorded with the supplementation of 5mM ACC at 30°C temperature after 24h of culture growth. All the nine strains showed acdS gene in the PCR amplification of that gene. No any rhizospheric Microbacterium species showing ACC deaminase activity have been reported earlier, therefore, we report here ACC deaminase activity in Microbacterium sp ECI-12A isolated from rice rhizosphere is a novel finding. DOI: http://dx.doi.org/10.3126/ijasbt.v1i1.7921 Int J Appl Sci Biotechnol, 2013, Vol. 1(1): 11-15


2020 ◽  
pp. 1186-1194
Author(s):  
Roberta Mendes dos Santos ◽  
Everlon Cid Rigobelo

The search for plant growth-promoting rhizobacteria is an ongoing need for the development of new bioinoculants for use in various crops, including sugarcane. Bacterial strains with various plant growth-promoting properties can contribute to sustainable agricultural production. The present study aimed to isolate, characterize and select sugarcane rhizobacteria from six different varieties through principal components analysis. This study selected 167 bacterial strains with the ability to fix nitrogen, produce indolacetic acid, exhibit cellulolytic activity, and solubilize phosphate and potassium were isolated. Of these 167 bacterial strains, seven were selected by principal component analysis and identified as belonging to the genera Staphylococcus, Enterobacter, Bacillus and Achromobacter. Bacillus thuringiensis IP21 presented higher potential for nitrogen fixation and CaPO4 and AlPO4 solubilization and a lower potential for K solubilization in sugarcane. Enterobacter asburiae IP24 was efficient in indolacetic acid production and CaPO4 and FePO4 solubilization and inefficient for Araxá apatite solubilization.


2008 ◽  
Vol 57 (4) ◽  
pp. 312-317 ◽  
Author(s):  
Venkadasamy Govindasamy ◽  
Murugesan Senthilkumar ◽  
Kishore Gaikwad ◽  
Kannepalli Annapurna

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