scholarly journals Analysis of the Genome of the Heavy Metal Resistant and Hydrocarbon-Degrading Rhizospheric Pseudomonas qingdaonensis ZCR6 Strain and Assessment of Its Plant-Growth-Promoting Traits

2021 ◽  
Vol 23 (1) ◽  
pp. 214
Author(s):  
Daria Chlebek ◽  
Tomasz Płociniczak ◽  
Sara Gobetti ◽  
Agata Kumor ◽  
Katarzyna Hupert-Kocurek ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Plant Growth ◽  
Contaminated Soils ◽  
Growth Promotion ◽  
Sulfur Metabolism ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Minimal Inhibitory Concentrations ◽  
Plant Growth Promoting

The Pseudomonas qingdaonensis ZCR6 strain, isolated from the rhizosphere of Zea mays growing in soil co-contaminated with hydrocarbons and heavy metals, was investigated for its plant growth promotion, hydrocarbon degradation, and heavy metal resistance. In vitro bioassays confirmed all of the abovementioned properties. ZCR6 was able to produce indole acetic acid (IAA), siderophores, and ammonia, solubilized Ca3(PO4)2, and showed surface active properties and activity of cellulase and very high activity of 1-aminocyclopropane-1-carboxylic acid deaminase (297 nmol α-ketobutyrate mg−1 h−1). The strain degraded petroleum hydrocarbons (76.52% of the initial hydrocarbon content was degraded) and was resistant to Cd, Zn, and Cu (minimal inhibitory concentrations reached 5, 15, and 10 mM metal, respectively). The genome of the ZCR6 strain consisted of 5,507,067 bp, and a total of 5055 genes were annotated, of which 4943 were protein-coding sequences. Annotation revealed the presence of genes associated with nitrogen fixation, phosphate solubilization, sulfur metabolism, siderophore biosynthesis and uptake, synthesis of IAA, ethylene modulation, heavy metal resistance, exopolysaccharide biosynthesis, and organic compound degradation. Complete characteristics of the ZCR6 strain showed its potential multiway properties for enhancing the phytoremediation of co-contaminated soils. To our knowledge, this is the first analysis of the biotechnological potential of the species P. qingdaonensis.

scholarly journals Bacteria Isolated from Wastewater Irrigated Agricultural Soils Adapt to Heavy Metal Toxicity While Maintaining Their Plant Growth Promoting Traits

2021 ◽  
Vol 13 (14) ◽  
pp. 7792
Author(s):  
Abdul Wahab Ajmal ◽  
Saleha Saroosh ◽  
Shah Mulk ◽  
Muhammad Nadeem Hassan ◽  
Humaira Yasmin ◽  
...  
Keyword(s):  
Plant Growth ◽  
Agricultural Soils ◽  
Culture Media ◽  
Growth Promotion ◽  
Metal Resistance ◽  
Rrna Gene ◽  
Gene Sequence Analysis ◽  
Plant Growth Promoting ◽  
Growth Promoting

The present study explored the plant growth promotion and bioremediation potential of bacteria inhabiting wastewater irrigated agricultural soils. Thirty out of 75 bacterial isolates (40%), 29/75 (39%) and 28/75 (37%) solubilized Zn, K and PO4 during plate essays respectively. Fifty-six percent of the isolates produced siderophores, while 30% released protease in vitro. Seventy-four percent of bacteria resisted Pb, Ni and Cd at various concentrations added to the culture media plates. Sixteen out of 75 (26%) isolates were able to fix N in Nbf medium. Among these 16 N fixers, N fixing nifH, nifD and nifK genes was detected through PCR in 8, 7 and 1 strain respectively using gene specific primers designed in the study with Enterobacter sp. having all three (nifHKD) genes. Isolated bacteria showed resemblance to diverse genera such as Bacillus, Pseudomonas, Enterobacter, Citrobacter, Acinetobacter, Serratia, Klebsiella and Enterococcus based on 16S rRNA gene sequence analysis. In addition to showing the best mineral solubilization and metal resistance potential, Citrobacter sp. and Enterobacter sp. also removed 87%, 79% and 43% and 86%, 78% and 51% of Ni, Cd and Pb, respectively, from aqueous solution. These potent bacteria may be exploited both for bioremediation and biofertilization of wastewater irrigated soils leading to sustainable agriculture.

scholarly journals Genomic and Physiological Investigation of Heavy Metal Resistance from Plant Endophytic Methylobacterium radiotolerans MAMP 4754, Isolated from Combretum erythrophyllum

2021 ◽  
Vol 18 (3) ◽  
pp. 997
Author(s):  
Mampolelo M. Photolo ◽  
Lungile Sitole ◽  
Vuyo Mavumengwana ◽  
Matsobane G. Tlou
Keyword(s):  
Heavy Metal ◽  
Plant Growth ◽  
Phthalate Esters ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Plant Growth Promoting Bacteria ◽  
Nickel Resistance ◽  
Metal Detoxification ◽  
Plant Growth Promoting ◽  
Growth Promoting

Combretum erythrophyllum is an indigenous southern African tree species, a metal hyperaccumulator that has been used as a phytoextraction option for tailing dams in Johannesburg, South Africa. In hyperaccumulators, metal detoxification has also been linked or attributed to the activities of endophytes, and, in this regard, metal detoxification can be considered a form of endophytic behavior. Therefore, we report herein on the identification of proteins that confer heavy metal resistance, the in vitro characterization of heavy metal resistance, and the production of plant growth-promoting (PGP) volatiles by Methylobacterium radiotolerans MAMP 4754. Multigenome comparative analyses of M. radiotolerans MAMP 4754 against eight other endophytic strains led to the identification of zinc, copper, and nickel resistance proteins in the genome of this endophyte. The maximum tolerance concentration (MTC) of this strain towards these metals was also investigated. The metal-exposed cells were analyzed by transmission electron microscopy (TEM). The ethyl acetate and chloroform extracts (1:1 v/v) of heavy metal untreated M. radiotolerans MAMP 4754 were also screened for the production of PGP compounds by Gas Chromatography–Mass Spectroscopy (GC/MS). The MTC was recorded at 15 mM, 4 mM, and 12 mM for zinc, copper, and nickel, respectively. The TEM analysis showed the accumulation of metals in the intracellular environment of M. radiotolerans MAMP 4754, while the GC/MS analysis revealed several plant growth-promoting compounds, including alcohols, phthalate esters, alkenes, ketones, sulfide derivatives, phenols, and thiazoles. Our findings suggest that the genetic makeup of M. radiotolerans MAMP 4754 encodes heavy metal resistant proteins that indicate hyperaccumulator-specific endophytic behavior and the potential for application in bioremediation. The production of plant growth-promoting volatiles in pure culture by M. raditotolerans MAMP 4754 is a characteristic feature for plant growth-promoting bacteria.

Heavy metal resistance mechanisms in actinobacteria for survival in AMD contaminated soils

Geochemistry ◽  
2005 ◽  
Vol 65 ◽  
pp. 131-144 ◽  
Author(s):  
Andre Schmidt ◽  
Götz Haferburg ◽  
Manuel Sineriz ◽  
Dirk Merten ◽  
Georg Büchel ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Contaminated Soils ◽  
Heavy Metal Resistance ◽  
Resistance Mechanisms ◽  
Metal Resistance

scholarly journals Bioremediation of lead using bacterial isolates and study their plant relieving effect on wheat under metal contamination

2020 ◽  
Vol 35 (1-2) ◽  
Author(s):  
Prashakha J. Shukla ◽  
Vishwa R. Vyas
Keyword(s):  
Heavy Metal ◽  
Stress Condition ◽  
Inhibitory Concentration ◽  
Anthropogenic Activities ◽  
Wheat Plant ◽  
Cost Effective ◽  
Heavy Metal Resistance ◽  
Metal Resistance

Increasing concentration of heavy metals due to various anthropogenic activities is a serious problem. To overcome this issue, many chemical and physical methods are available but they are either directly or indirectly harmful to nature. By these methods more quality of chemicals are wasted. So, bioremediation is the best method to remove pollutants. It is an eco-friendly and cost-effective process. A low concentration of heavy metal is required to plant for their growth and metabolic process but at higher concentration, plants do not survive. With the use of microbes, we can survive plants at certain levels. During this work heavy metal tolerating microorganism was isolated and purified. Various tests were performed like staining, minimum inhibitory concentration, multiple heavy metal resistance, multiple antibiotic resistance, biochemical test, DNA isolation, in vitro examination of the wheat plant under the stress condition of lead (1000ppm).

scholarly journals Seed-Biopriming of Durum Wheat with Diazotrophic Plant Browth Promoting Bacteria (PGPB) Enhanced Tolerance to Fusarium Head Blight (FHB) and Salinity Stress

2019 ◽  
Author(s):  
Adel Hadj Brahim ◽  
Mouna Jlidi ◽  
Lobna Daoud ◽  
Manel Ben-Ali ◽  
Asmahen Akremi ◽  
...  
Keyword(s):  
Plant Growth ◽  
Durum Wheat ◽  
Abiotic Stresses ◽  
Growth Promotion ◽  
Head Blight ◽  
Biotic And Abiotic Stresses ◽  
Plant Growth Promoting ◽  
Seed Biopriming

Abstract Background The use of bioinoculants based on plant growth-promoting bacteria (PGPB) to promote plant growth under biotic and abiotic stresses is in full expansion. To our knowledge much work has not been, thus far, done on seed-biopriming of durum wheat for tolerance to biotic and abiotic stresses. In the present work, we report detailed account of the effectiveness a potent bacterial strain with proven plant growth-promoting ability and antimicrobial activity. The isolate was selected following screening of several bacterial strains isolated from halophytes that grow in a coastal saline soil in Tunisia for their role in enhancing durum wheat tolerance to both salinity stress and head blight disease.Results Accordingly, Bacillus strains MA9, MA14, MA17 and MA19 were found to have PGPB characteristics as they produced indole-3-acetic acid, siderophores and lytic enzymes, fixed free atmospheric nitrogen, and solubilized inorganic phosphate, in vitro . The in vivo study that involved in planta inoculation assays under control (25 mM NaCl) and stress (125 mM NaCl) conditions indicated that all PGPB strains significantly ( P < 0.05) increased the total plant length, dry weight, root area, seed weight, nitrogen, protein and total mineral content. On the other hand, strain MA17 reduced Fusarium Head Blight (FHB) disease incidence in wheat explants by 64.5%, showing that the strain has antifungal activity as was also displayed by in vitro inhibition study.Conclusions Both in vitro and in vivo studies showed that MA9, MA14 MA9, MA14, MA17 and MA19 strains were able to play the PGPB role. Yet, biopriming with Bacillus strain MA17 offered the highest bioprotection against FHB, plant growth promotion, and salinity tolerance. Hence, the MA17 strain should further be evaluated under field condition and formulated for commercial production. Besides, the strain could further be evaluated for its potential role in bioprotection and growth promotion of other crop plants. We believe, the strain has potential to significantly contribute to wheat production in the arid and semi-arid region, especially the salt affected Middle Eastern Region, besides its potential role in improving wheat production under biotic and abiotic stresses in other parts of the world.

Enhancement of verticillium wilt resistance in tomato transplants by in vitro co-culture of seedlings with a plant growth promoting rhizobacterium (Pseudomonas sp. strain PsJN)

1998 ◽  
Vol 44 (6) ◽  
pp. 528-536 ◽  
Author(s):  
V K Sharma ◽  
J Nowak
Keyword(s):  
Plant Growth ◽  
Verticillium Wilt ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Disease Suppression ◽  
Pseudomonas Sp ◽  
Plant Growth Promoting ◽  
Growth Promoting

The potential utilization of a plant growth promoting rhizobacterium, Pseudomonas sp. strain PsJN, to enhance the resistance of tomato transplants to verticillium wilt was investigated. Plant growth and disease development were tested on the disease-susceptible cultivar Bonny Best after Verticillium dahliae infection of tissue culture plantlets bacterized in vitro (by co-culturing with the bacterium) and seedlings bacterized in vivo (after 3 weeks growth in the greenhouse). Significant differences in both disease suppression and plant growth were obtained between in vitro bacterized and nonbacterized (control) plants. The degree of protection afforded by in vitro bacterization depended on the inoculum density of V. dahliae; the best and worst protection occurred at the lowest (103 conidia ·mL-1) and highest (106 conidia ·mL-1) levels, respectively. In contrast, the in vivo bacterized tomatoes did not show plant growth promotion when compared to the nonbacterized control plants. When challenged with Verticillium, significant growth differences between in vivo bacterized plants (26.8% for shoot height) and nonbacterized controls were only seen at the 3rd week after inoculation. Compared with the in vitro inoculation, there was no delay in the verticillium wilt symptom expression, even at the lowest concentration of V. dahliae, by in vivo PsJN inoculation. These results suggest that endophytic colonization of tomato tissues is required for the Verticillium-resistance responses. Plant growth promotion preceeds the disease-resistance responses and may depend on the colonization thresholds and subsequent sensitization of hosts.Key words: Pseudomonas sp., plant growth promoting rhizobacterium, Verticillium dahliae, tomato, colonization, plant growth promotion, disease suppression.

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