scholarly journals Plant Growth Enhancement using Rhizospheric Halotolerant Phosphate Solubilizing Bacterium Bacillus licheniformis QA1 and Enterobacter asburiae QF11 Isolated from Chenopodium quinoa Willd

2020 ◽  
Vol 8 (6) ◽  
pp. 948
Author(s):  
Ismail Mahdi ◽  
Nidal Fahsi ◽  
Mohamed Hafidi ◽  
Abdelmounaaim Allaoui ◽  
Latefa Biskri

Plant growth-promoting rhizobacteria represent a promising solution to enhancing agricultural productivity. Here, we screened phosphate solubilizing bacteria from the rhizospheric soil of Chenopodium quinoa Willd and assessed their plant-growth promoting rhizobacteria (PGPR) properties including production of indole-3-acetic acid (IAA), siderophores, hydrogen cyanide (HCN), ammonia and extracellular enzymes. We also investigated their tolerance to salt stress and their capacity to form biofilms. Two isolated strains, named QA1 and QF11, solubilized phosphate up to 346 mg/L, produced IAA up to 795.31 µg/mL, and tolerated up to 2 M NaCl in vitro. 16S rRNA and Cpn60 gene sequencing revealed that QA1 and QF11 belong to the genus Bacillus licheniformis and Enterobacter asburiae, respectively. In vivo, early plant growth potential showed that quinoa seeds inoculated either with QA1 or QF11 displayed higher germination rates and increased seedling growth. Under saline irrigation conditions, QA1 enhanced plant development/growth. Inoculation with QA1 increased leaf chlorophyll content index, enhanced P and K+ uptake and decreased plant Na+ uptake. Likewise, plants inoculated with QF11 strain accumulated more K+ and had reduced Na+ content. Collectively, our findings support the use of QA1 and QF11 as potential biofertilizers.

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 316
Author(s):  
Nidal Fahsi ◽  
Ismail Mahdi ◽  
Abdelhalem Mesfioui ◽  
Latefa Biskri ◽  
Abdelmounaaim Allaoui

In recent years, the low Zn content of wheat has become critical. Consequently, solutions that can improve the Zn nutrition of wheat are highly researched. In the present investigation, we aimed to evaluate the potential benefits of phosphate-solubilizing bacteria isolated from Ziziphus lotus on wheat seedling growth. Based on the phosphate-solubilizing criteria, four isolated strains, J16, J143, J146, and J158, were identified by 16SrRNA gene sequencing as Pseudomonas moraviensis, Bacillus halotolerans, Enterobacter hormaechei, and Pseudomonas frederiksbergensis, respectively. Studies of the conventional properties of plant growth-promoting rhizobacteria (PGPR) showed that E. hormaechei J146 produced up to 550 mg·L−1 of indole-3-acetic acid (IAA). Siderophores and ammonia were produced by all strains but cellulase was restricted to B. halotolerans J143, whereas proteases were missing in E. hormaechei J146 and P. frederiksbergensis J158. E. hormaechei J146 tolerate up to 1.5 mg·L−1 of copper and cadmium, while B. halotolerans J143 withstood 1.5 mg·L−1 of nickel. Strains B. halotolerant J143, E. hormaechei J146, and P. frederiksbergensis J158 remarkably improved wheat seed germination, plant growth, and Zn absorption. Lastly, nutrient measurement revealed that a wheat plant inoculated with E. hormaechei J146 and P. frederiksbergensis J158 increased its nitrogen and potassium uptake by up to 17%.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1071
Author(s):  
Minchong Shen ◽  
Jiangang Li ◽  
Yuanhua Dong ◽  
Hong Liu ◽  
Junwei Peng ◽  
...  

Microbial treatment has recently been attracting attention as a sustainable agricultural strategy addressing the current problems caused by unreasonable agricultural practices. However, the mechanism through which microbial inoculants promote plant growth is not well understood. In this study, two phosphate-solubilizing bacteria (PSB) were screened, and their growth-promoting abilities were explored. At day 7 (D7), the lengths of the root and sprout with three microbial treatments, M16, M44, and the combination of M16 and M44 (Com), were significantly greater than those with the non-microbial control, with mean values of 9.08 and 4.73, 7.15 and 4.83, and 13.98 and 5.68 cm, respectively. At day 14 (D14), M16, M44, and Com significantly increased not only the length of the root and sprout but also the underground and aboveground biomass. Differential metabolites were identified, and various amino acids, amino acid derivatives, and other plant growth-regulating molecules were significantly enhanced by the three microbial treatments. The profiling of key metabolites associated with plant growth in different microbial treatments showed consistent results with their performances in the germination experiment, which revealed the metabolic mechanism of plant growth-promoting processes mediated by screened PSB. This study provides a theoretical basis for the application of PSB in sustainable agriculture.


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.


2021 ◽  
Vol 11 ◽  
Author(s):  
Jinge Xie ◽  
Zongqiang Yan ◽  
Guifen Wang ◽  
Wenzhi Xue ◽  
Cong Li ◽  
...  

Phosphorus in the soil accessible to plants can easily be combined with calcium ion, the content of which is high in karst rocky desertification (KRD) regions, thereby resulting in a low utilization efficiency of phosphorus. The application of phosphate-solubilizing bacteria (PSB) from the KRD region would facilitate enhanced phosphate availability in the soil. In the present study, the strains belonging to Acinetobacter, Paraburkholderia, and Pseudomonas with efficient phosphate-solubilizing ability were isolated from fruit tree rhizosphere soils in KRD regions. Particularly, Acinetobacter sp. Ac-14 had a sustained and stable phosphate-solubilizing ability (439–448 mg/L, 48–120 h). Calcium carbonate decreased the phosphate-solubilizing ability in liquid medium; however, it did not affect the solubilization index in agar-solidified medium. When cocultivated with Arabidopsis thaliana seedling, Ac-14 increased the number of lateral roots, fresh weight, and chlorophyll content of the seedlings. Metabolomics analysis revealed that Ac-14 could produce 23 types of organic acids, majorly including gluconic acid and D-(-)-quinic acid. Expression of Ac-14 glucose dehydrogenase gene (gcd) conferred Pseudomonas sp. Ps-12 with a sustained and stable phosphate-solubilizing ability, suggesting that the production of gluconic acid is an important mechanism that confers phosphate solubilization in bacteria. Moreover, Ac-14 could also produce indole acetic acid and ammonia. Collectively, the isolated Ac-14 from KRD regions possess an efficient phosphate-solubilizing ability and plant growth-promoting effect which could be exploited for enhancing phosphorus availability in KRD regions. This study holds significance for the improvement of soil fertility and agricultural sustainable development in phosphorus-deficient KRD regions.


Author(s):  
Sri Purwaningsih ◽  
Dwi Agustiyani ◽  
Satjiya Antonius

Background and Objectives: This study was aimed to isolate Rhizobium spp., from the plant rhizosphere and to investigate their effects on the growth of peanut (Arachis hypogaea L.) as plant growth-promoting rhizobacteria (PGPR). Materials and Methods: The isolates were characterized using YEMA, YEMA + Congo Red, and YEMA + Bromothymol blue (BTB) media. The Rhizobium was tested qualitatively for their ability to produce indole acetic acid (IAA), siderophores, proteases, nitrogenases as well as phosphate solubilizing activity. A greenhouse experiment was carried out to elucidate the effect of Rhizobium inoculation on Arachis hypogaea L. growth. Results: Eleven isolates were obtained in YEMA media and they were red-pink in the YEMA + Congo Red media. The YEMA + BTB test showed that 2 isolates were slow-growing and the rest were fast-growing isolates. Seven isolates produced siderophores, 5 were capable of phosphate solubilizing, 9 isolates produced protease enzyme, 4 isolates could produce IAA, and 7 isolates could fix nitrogen. The B1 and the combination of some high trait-isolate treatments in Y gave the best results on Arachis hypogaea L. growth. Conclusion: These isolates can be developed as biological fertilizer agents for the peanut plant.


2007 ◽  
Vol 2 (3) ◽  
pp. 326-333 ◽  
Author(s):  
A. Vikram ◽  
H. Hamzehzarghani . ◽  
A.R. Alagawadi . ◽  
P.U. Krishnaraj . ◽  
B.S. Chandrashekar .

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