scholarly journals Selection of Mercury-Resistant PGPR Strains Using the BMRSI for Bioremediation Purposes

2021 ◽  
Vol 18 (18) ◽  
pp. 9867
Author(s):  
Daniel González ◽  
Marina Robas ◽  
Agustín Probanza ◽  
Pedro A. Jiménez
Keyword(s):  
Contaminated Soils ◽  
Plant Growth Promoting Rhizobacteria ◽  
Mining District ◽  
Bacterial Strains ◽  
Ciudad Real ◽  
Agriculture Industry ◽  
Suitability Index ◽  
Plant Growth Promoting ◽  
Potential Use

Heavy metal pollution of soil, particularly by mercury (Hg), is a problem that can seriously affect the environment and human health. For this reason, it is necessary to take steps to remediate these environments, prevent potential adverse effects, and restore these areas for subsequent use in agriculture, industry, ranching, and forestry. The present study has selected 40 bacterial strains from rhizosphere and bulk soil that grow naturally in high Hg-contaminated soils from the Almadén mining district in Ciudad Real, Spain. With the objective of evaluating the potential use of these strains in phyto-rhizoremediation, an evaluation and statistical analysis of their PGPR (Plant-Growth-Promoting Rhizobacteria) activity at different levels of Hg was carried out as the first condition of selection for their potential use in bioremediation. In addition, a Hg MBC (Maximum Bactericidal Concentration) was performed with the aim of selecting the strains with high Hg tolerance. Finally, strains with potential biotechnological use have been proposed according to the Bio-Mercury Remediation Suitability Index (BMRSI) criteria, which consider indole-3-acetic acid (IAA) production, acid 1- aminocyclopropane-1-carboxylic deaminase (ACCd) activity, phosphates solubilization, and siderophore production measured in the presence of Hg, as well as its MBC to Hg. The strains selected for further in vivo and in situ processes must reach at least an MBC (Hg) > 100 μg/mL and BMRSI ≥ 6.5.

scholarly journals Evaluation of the PGPR Capacity of Four Bacterial Strains and Their Mixtures, Tested on Lupinus albus var. Dorado Seedlings, for the Bioremediation of Mercury-Polluted Soils

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1293
Author(s):  
Daniel González ◽  
Carlota Blanco ◽  
Agustín Probanza ◽  
Pedro A. Jiménez ◽  
Marina Robas
Keyword(s):  
Plant Growth ◽  
Contaminated Soils ◽  
Lupinus Albus ◽  
Plant Growth Promoting Rhizobacteria ◽  
Mining District ◽  
Bacterial Strains ◽  
Toxic Heavy Metals ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
High Concentrations

Soil contamination by mercury, which is one of the most toxic heavy metals due to its bioaccumulative capacity, poses a risk to the environment as well as health. The Almadén mining district in Ciudad Real, Spain is one of the most heavily-polluted sites in the world, making the soils unusable. Bioremediation, and more specifically phyto-rhizoremediation, based on the synergistic interaction established between plant and Plant Growth Promoting Rhizobacteria (PGPR), improves the plant's ability to grow, mobilize, accumulate, and extract contaminants from the soil. The objective of this study is to evaluate the plant growth-promoting ability of four PGPR strains (and mixtures), isolated from the bulk soil and rhizosphere of naturally grown plants in the Almadén mining district, when they are inoculated in emerged seeds of Lupinus albus, var. Dorado in the presence of high concentrations of mercury. After 20 days of incubation and subsequent harvesting of the seedlings, biometric measurements were carried out at the root and aerial levels. The results obtained show that the seeds treatment with PGPR strains improves plants biometry in the presence of mercury. Specifically, strain B2 (Pseudomonas baetica) and B1 (Pseudomonas moraviensis) were those that contributed the most to plant growth, both individually and as part of mixtures (CS5 and CS3). Thus, these are postulated to be good candidates for further in situ phyto-rhizoremediation tests of mercury-contaminated soils.

scholarly journals Bio-Mercury Remediation Suitability Index: A Novel Proposal That Compiles the PGPR Features of Bacterial Strains and Its Potential Use in Phytoremediation

2021 ◽  
Vol 18 (8) ◽  
pp. 4213
Author(s):  
Marina Robas ◽  
Pedro A. Jiménez ◽  
Daniel González ◽  
Agustín Probanza
Keyword(s):  
Phosphate Solubilization ◽  
Plant Growth Promoting Rhizobacteria ◽  
Soil Bioremediation ◽  
Bacterial Strains ◽  
Auxin Production ◽  
Suitability Index ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Potential Use ◽  
Selection Of

Soil pollution from heavy metals, especially mercury, is an environmental problem for human health. Biological approaches offer interesting tools, which necessarily involve the selection of organisms capable of transforming the environment via bioremediation. To evaluate the potential use of microorganisms in phytorhizoremediation, bacterial strains were isolated from rhizospheric and bulk soil under conditions of chronic natural mercury, which were identified and characterized by studying the following: (i) their plant growth promoting rhizobacteria (PGPR) activities; and (ii) their maximum bactericide concentration of mercury. Information regarding auxin production, phosphate solubilization, siderophore synthesis and 1-aminocyclopropane-1-carboxylic acid deaminase (ACCd) capacity of the isolates was compiled in order to select the strains that fit potential biotechnological use. To achieve this objective, the present work proposes the Bio-Mercury Remediation Suitability Index (BMR-SI), which reflects the integral behavior of the strains for heavy metal polluted soil bioremediation. Only those strains that rigorously fulfilled all of the established criteria were selected for further assays.

scholarly journals Efecto de la somatotropina bovina recombinante (bST) al momento del destete sobre la productividad de ovejas

2019 ◽  
pp. 5-15
Author(s):  
Blanca Estela Gómez-Luna ◽  
Rafael Alejandro Veloz-García ◽  
César Díaz-Pérez ◽  
Juan Carlos Ramírez-Granados
Keyword(s):  
Mycorrhizal Fungi ◽  
Dry Weight ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Strains ◽  
Beneficial Microorganisms ◽  
Randomized Experimental Design ◽  
Plant Growth Promoting ◽  
Phytopathogenic Microorganisms ◽  
Root Size ◽  
Potential Use

The Mexican marigold flower (Tagetes erecta) is a plant native to Mexico, the uses are: pigments, flavoring, perfumery, ornamental, insecticides, nematicides and medicinal. In the soil there is a great richness of microorganisms mycorrhizal fungi and plant growth promoting rhizobacteria with an important role in the processes that affect the transformation of nutrients in the soil and their availability for plants and protection against phytopathogenic microorganisms. The objective of this work was to evaluate the effect of the use of beneficial microorganisms in the development of the cempasúchil flower compared with the application of a fertilizer. The bacterial strains were identified as 225, 254, 302 and an inoculum of mycorrhizal fungi. The Blue Garden fertilizer. Fresh weight, dry weight, number of flowers, root size were determined. A completely randomized experimental design and Tukey test were used. According to the results obtained, the best treatments that could have a potential use were the following treatments: fertilizer, strain 254, strain 302 and strain 254 and mycorrhiza. The use of beneficial microorganisms for the production of Mexican marigold flowers was shown to be effective and comparable with the application of fertilizer, therefore reducing its use and even eliminating it.

scholarly journals PGPR Characteristics of Rhizospheric Bacteria to Understand the Mechanisms of Faba Bean Growth

Proceedings ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 27
Author(s):  
Rim Tinhinen Maougal ◽  
Maya Kechid ◽  
Chaima Ladjabi ◽  
Abdelhamid Djekoun
Keyword(s):  
Plant Growth ◽  
Faba Bean ◽  
Biochemical Characterization ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Strains ◽  
Rhizospheric Bacteria ◽  
Plant Growth Promoting ◽  
Pgpr Traits ◽  
Taxonomic Groups ◽  
High Degree

Rhizobacteria play an important role in maintaining soil balance. Among these bacteria, there are those taht have shown their ability to promote the growth of plants, known as Plant Growth Promoting Rhizobacteria (PGPR). In our work, we are interested in characterizing 110 bacterial strains isolated in the field in the region of Ben Badis (Constantine Algeria) from 5 varieties of faba bean. Phenotypic and biochemical characterization showed that most of the isolates are cream-colored, slightly raised, flat and opaque, Gram−, catalase+ and oxidase−, and Bacillus form. PCA analysis allowed us to select 40 isolates with a high degree of variability to continue our work. The results obtained have directed us towards different taxonomic groups (rhizobium, Pseudomonas, Bacillus etc.). The evaluation of the PGPR potential of bacteria (phytostimulation, biofertilization and biocontrol), showed that 100% of bacteria are able to produce auxin at different concentrations, with the highest concentration (177.77 µg/mL) for the isolate 6, and that more than 50% of isolates are capable of producing nitrogen, ammonia and phytate mineralization. These PGPR traits have a direct effect on plant growth of five varieties of the faba bean and can be used to select the best performing bacteria for inoculation tests.

scholarly journals Role of Two Plant Growth-Promoting Bacteria in Remediating Cadmium-Contaminated Soil Combined with Miscanthus floridulus (Lab.)

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 912
Author(s):  
Shuming Liu ◽  
Hongmei Liu ◽  
Rui Chen ◽  
Yong Ma ◽  
Bo Yang ◽  
...  
Keyword(s):  
Plant Growth ◽  
Contaminated Soils ◽  
Translocation Factor ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Strains ◽  
Pgp Traits ◽  
Cd Tolerance ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Cd Translocation

Miscanthus spp. are energy plants and excellent candidates for phytoremediation approaches of metal(loid)s-contaminated soils, especially when combined with plant growth-promoting bacteria. Forty-one bacterial strains were isolated from the rhizosphere soils and roots tissue of five dominant plants (Artemisia argyi Levl., Gladiolus gandavensis Vaniot Houtt, Boehmeria nivea L., Veronica didyma Tenore, and Miscanthus floridulus Lab.) colonizing a cadmium (Cd)-contaminated mining area (Huayuan, Hunan, China). We subsequently tested their plant growth-promoting (PGP) traits (e.g., production of indole-3-acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase) and Cd tolerance. Among bacteria, two strains, Klebsiella michiganensis TS8 and Lelliottia jeotgali MR2, presented higher Cd tolerance and showed the best results regarding in vitro growth-promoting traits. In the subsequent pot experiments using soil spiked with 10 mg Cd·kg−1, we investigated the effects of TS8 and MR2 strains on soil Cd phytoremediation when combined with M. floridulus (Lab.). After sixty days of planting M. floridulus (Lab.), we found that TS8 increased plant height by 39.9%, dry weight of leaves by 99.1%, and the total Cd in the rhizosphere soil was reduced by 49.2%. Although MR2 had no significant effects on the efficiency of phytoremediation, it significantly enhanced the Cd translocation from the root to the aboveground tissues (translocation factor > 1). The combination of K. michiganensis TS8 and M. floridulus (Lab.) may be an effective method to remediate Cd-contaminated soils, while the inoculation of L. jeotgali MR2 may be used to enhance the phytoextraction potential of M. floridulus.

scholarly journals Selection of Saccharum spp. rhizobacteria with growth-promoting properties using PCA analysis

2020 ◽  
pp. 1186-1194
Author(s):  
Roberta Mendes dos Santos ◽  
Everlon Cid Rigobelo
Keyword(s):  
Plant Growth ◽  
Principal Component ◽  
Plant Growth Promoting Rhizobacteria ◽  
Cellulolytic Activity ◽  
Bacterial Strains ◽  
Saccharum Spp ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Enterobacter Asburiae ◽  
Selection Of

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.

Sign in / Sign up

Export Citation Format

Share Document