scholarly journals Rhizodegradation of Pyrene by a Non-pathogenic Klebsiella pneumoniae Isolate Applied With Tagetes erecta L. and Changes in the Rhizobacterial Community

2021 ◽  
Vol 12 ◽  
Author(s):  
Jina Rajkumari ◽  
Yashmin Choudhury ◽  
Kasturi Bhattacharjee ◽  
Piyush Pandey
Keyword(s):  
Klebsiella Pneumoniae ◽  
Plant Growth ◽  
Growth Promotion ◽  
Diversity Index ◽  
Ornamental Plant ◽  
Tagetes Erecta ◽  
Root Weight ◽  
Available Nitrogen ◽  
Core Microbiome ◽  
Bacterial Phyla

The non-clinical Klebsiella pneumoniae variants, isolated from different environments, are now well acknowledged for their role in plant-growth promotion and biodegradation of pollutants. In the present study, a non-clinical environmental isolate K. pneumoniae AWD5 is being described for rhizoremediation of pyrene, applied through the rhizosphere of an ornamental plant, Tagetes erecta L (marigold). The non-pathogenic nature of AWD5 was established using an in vivo mouse model experiment, where AWD5 was unable to cause lung infection in tested mice. Degradation of pyrene, in the presence of succinate as co-substrate, was observed to be 87.5% by AWD5, after 21 days of incubation in minimal (Bushnell–Hass) medium in vitro conditions. Consequently, the bacterial inoculation through the rhizosphere of T. erecta L. plants resulted in 68.61% degradation of pyrene, which was significantly higher than control soil. Inoculation of AWD5 also improved plant growth and exhibited an increase in root length (14.64%), dry root weight (80.56%), shoot length (3.26%), and dry shoot weight (45.35%) after 60 days of incubation. T. erecta L., an ornamental plant, was also found to be suitable for bioremediation of pyrene. The effect of AWD5 application, and rhizoremediation process, on rhizosphere bacterial diversity and community structure has been studied using the metagenomic analysis of the 16S (V3–V4) region of rRNA. 37 bacterial phyla constituted the core microbiome, which was dominated by Proteobacteria followed by Actinobacteria, Actinobacteria, and Planctomycetes for all the treatments. AWD5 inoculation enhanced the relative abundance of Firmicutes and Acidobacteria as compared with other treatments. Genus Kaistobacter and Verrucomicrobia were found to be an abundant indigenous population in pyrene-spiked soils. Bacterial richness and diversity were analyzed using the Shannon–Wiener (H) index. A lower diversity index was observed in pyrene-spiked soils. Canonical correspondence analysis (CCA) showed a possible linkage with plant growth attributes and available nitrogen content that influences diversity and abundance of the bacterial community.

Isolation, identification and characterization of native plant growth promoting bacteria and their plant growth promotion in Zea mays

2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Root Length ◽  
Growth Promotion ◽  
Shoot Length ◽  
Root Weight ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Shoot Weight

In the present rapid growing world, need for a sustainable agricultural practice which helps in meeting the adequate food demand is much needed. In this context, plant growth promoting bacteria were brought into the spot light by the researchers. Though the plant growth promoting bacteria have several beneficial applications, due to some of the disadvantages in the field conditions, they lagged behind. In the current research work, native PGPR were isolated from the rhizosphere soil samples of maize with an aim to isolate the nitrogen fixing, phosphate solubilising and potash solubilising bacteria. Out of the several isolates, potent PGPR isolates viz., Paenibacillus durus PCPB067, Bacillus megaterium PCBMG041 and Paenibacillus glucanolyticus PCPG051 were isolated and identified by using the 16 S rRNA gene sequencing studies. Genomic DNA sequences obtained were deposited in the NCBI Genbank and accession numbers were assigned as MW793452, MW793456 and MW843633. In order to check the efficacy of the PGPR isolates, pot trials were conducted by taking maize as the host plant. Several parameters viz. shoot length, shoot weight, root length, root weight and weight of the seeds were tested in which PGP treatment showed good results (shoot length - 187±3.5 cm, shoot weight - 31±4 g, root length - 32±3.6 cm, root weight - 17±2 g, yield- 103.3±6.1 g) when compared to the chemical fertilizer treatment (shoot length - 177±3.5 cm, shoot weight - 25±3.6 g, root length - 24±3.5 cm, root weight - 14.6±1.52 g, yield- 85.6±7.6 g). Based on the results, it can be stated that these native PGPR isolates can be effectively used in the plant growth promotion of maize.

Bacillus licheniformis M2-7 IMPROVES GROWTH, DEVELOPMENT AND YIELD OF Capsicum annuum L.

Agrociencia ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 227-242
Author(s):  
Alejandro Bolaños Dircio ◽  
Jeiry Toribio Jiménez ◽  
Miguel Á. Rodríguez Barrera ◽  
Giovanni Hernández Flores ◽  
Erubiel Toledo Hernández ◽  
...  
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Capsicum Annuum ◽  
Bacillus Licheniformis ◽  
Growth Promotion ◽  
Growth And Yield ◽  
Phytopathogenic Fungus ◽  
Root Weight ◽  
Plant Growth Promoting Bacteria ◽  
Capsicum Annuum L

Plant growth promoting bacteria are known to directly or indirectly influence the development and yield of plants. Studies that show the biotechnological potential of these bacteria as biofertilizers are thus important. The objective of this study was to evaluate the growth capacities of strains M2-7 and LYA12 and define whether their interactions with Capsicum annuum L. increases production. The hypothesis was that the Bacillus licheniformis strains have capacities to promote growth and yield of Capsicum annuum L. First, these strains were evaluated in vitro in selective culture media to detect those direct or indirect mechanisms for plant growth promotion. Then, the effect of both strains on seed germination and the effect of strain M2-7 were studied on the in vivo development of C. annuum L. The experimental design was completely randomized with 3 treatments and 3 repetitions. Data was analyzed with ANOVA and Tukey test (p≤0.05). Results showed that the bacterial strains were able to fix nitrogen, solubilize tricalcium phosphate Ca3 (PO4)2, produce gibberellins, lytic enzymes (amylases, proteases, lipases and esterases), biosurfactants, volatile compounds; and significantly inhibit growth (p≤0.05) of the phytopathogenic fungus Colletotrichum sp. Likewise, the strains M2-7 and LYA12 increased (p≤0.05) by 89 and 78% the seed germination of C. annuum L. M2-7 enhanced fresh weight (235%), stem diameter (308%), root weight, number and weight of fruits (316%), as compared to treatment 1 (Nitrofoska) and 3 (Control). Therefore, B. licheniformis M2-7 strain is attractive to develop the formulation of biofertilizers; aiming to improve yield of some horticultural crops towards a sustainable and ecological agriculture.

scholarly journals Mycogenic Nano-Complex for Plant Growth Promotion and Bio-Control of Pythium aphanidermatum

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1858
Author(s):  
Shaima M.N. Moustafa ◽  
Rania H. Taha
Keyword(s):  
Plant Growth ◽  
Metal Complex ◽  
Vicia Faba ◽  
Growth Promotion ◽  
Pathogenic Fungus ◽  
Pythium Aphanidermatum ◽  
Root Weight ◽  
Total Biomass ◽  
Growth Promoter ◽  
Green Method

(1) Background: biological way is one of the most ecofriendly and safe strategies for nanomaterials synthesis. So, biosynthesis-green method was used for the preparation of Zn(II) complex (in the Nano scale) from the reaction of the schiff base ligand 2,2′-((1E,1′E)-(1,2-phenylenebis (azanylylidene)), bis(methanylylidene))bis(4-bromophenol), and Zn(II)sulphate. The biogenic ZnNP-T was characterized by different methods. Our purpose was to evaluate the ability of biosynthesis-green method for the preparation of Zn(II) complex as an antifungal agent against diseases from fungal species. (2) Methods: in this work, isolates of Pythium aphanidermatum and Trichderma harzianum were obtained, and Trichderma harzianum was used to prepare nano metal complex. We tested the pathogenicity of nano metal complex against seedling and germination of seeds, and we evaluated the effectiveness of ZnNP-T for growth promotion of Vicia feba in early stage and inhibitory activity against Pythium aphanidermatum. (3) Results: antagonistic activity of ZnNP-T was tested in vitro against Pythium aphanidermatum, and then the growth rates of Vicia faba were determined. The obtained data revealed that mycelial growth of pathogenic fungus was inhibited about 73.8% at 20 ppm. In addition, improved the total biomass of Vicia faba in the presence of P. aphanidermatum. All concentration of ZnNP-T positively affected root weight of Vicia faba seedlings, and positively affected shoot weight. Root and shoot lengths were affected by using 20 ppm of ZnNP-T with up to 180 and 96.5 mm of shoot and root length compared to that of the control, while germination percentage was significantly enhanced with up to 100% increase after 72 h of germination. (4) Conclusion: one of the modern challenges in vegetable or fruit production is to enhance seed germination and to grow healthy plants with strong root system. In future, there should be a focus on using of biogenic Zinc nano-complex as plant growth promoter agents.

scholarly journals Exploration of Klebsiella pneumoniae M6 for paclobutrazol degradation, plant growth attributes, and biocontrol action under subtropical ecosystem

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261338
Author(s):  
Govind Kumar ◽  
Shatrohan Lal ◽  
Shailendra K. Maurya ◽  
A. K. Bhattacherjee ◽  
Parul Chaudhary ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Plant Growth ◽  
Growth Promotion ◽  
Degradation Kinetics ◽  
Principal Component ◽  
Pathogenic Fungi ◽  
Inoculum Size ◽  
Growth Promoter ◽  
Degraded Land ◽  
Soil System

In recent times, injudicious use of paclobutrazol (PBZ) in mango orchards deteriorates the soil quality and fertility by persistence nature and causes a serious ecosystem imbalance. In this study, a new Klebsiella pneumoniae strain M6 (MW228061) was isolated from mango rhizosphere and characterized as a potent plant growth promoter, biocontrol, and PBZ degrading agent. The strain M6 efficiently utilizes PBZ as carbon, energy and nitrogen source and degrades up to 98.28% (50 mgL-1 initial conc.) of PBZ at 15th day of incubation in MS medium. In the soil system first order degradation kinetics and linear model suggested 4.5 days was the theoretical half-life (t1/2 value) of PBZ with strain M6. Box Behnken design (BBD) model of Response surface methodology (RSM) showed pH 7.0, 31°C temperature, and 2.0 ml inoculum size (8 x 109 CFU mL-1) was optimized condition for maximum PBZ degradation with strain M6. Plant growth promoting attributes such as Zn, K, PO4 solubilization IAA, HCN and NH3 production of strain M6 showed positive results and were assessed quantitatively. The relation between plant growth promotion and PBZ degradation was analyzed by heat map, principal component analysis (PCA) and, clustal correlation analysis (CCA). Strain M6 was also showing a significant biocontrol activity against pathogenic fungi such as Fusarium oxysporum (MTCC–284), Colletotrichum gloeosporioides (MTCC– 2190), Pythium aphanidermatum (MTCC– 1024), Tropical race 1 (TR -1), and Tropical race 4 (TR -4). Hence, results of the study suggested that strain M6 can be utilized as an effective bio-agent to restore degraded land affected by persistent use of paclobutrazol.

scholarly journals Biological Control of Chili Damping-Off Disease, Caused by Pythium myriotylum

2021 ◽  
Vol 12 ◽  
Author(s):  
Sajjad Hyder ◽  
Amjad Shahzad Gondal ◽  
Zarrin Fatima Rizvi ◽  
Rashida Atiq ◽  
Muhammad Irtaza Sajjad Haider ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Disease Suppression ◽  
Root Weight ◽  
Dual Culture ◽  
Bacterial Isolates ◽  
Damping Off ◽  
Pythium Myriotylum ◽  
Pgp Traits

Pythium myriotylum is a notorious soil-borne oomycete that causes post-emergence damping-off in chili pepper. Of various disease management strategies, utilization of plant growth promoting rhizobacteria (PGPR) in disease suppression and plant growth promotion is an interesting strategy. The present study was performed to isolate and characterize PGPR indigenous to the chili rhizosphere in Pakistan, and to test the potential to suppress the damping-off and plant growth promotion in chili. Out of a total of 28 antagonists, eight bacterial isolates (4a2, JHL-8, JHL-12, 1C2, RH-24, 1D, 5C, and RH-87) significantly suppressed the colony growth of P. myriotylum in a dual culture experiment. All the tested bacterial isolates were characterized for biochemical attributes, and 16S rRNA sequence based phylogenetic analysis identified these isolates as Flavobacterium spp., Bacillus megaterium, Pseudomonas putida, Bacillus cereus, and Pseudomonas libanensis. All the tested bacterial isolates showed positive test results for ammonia production, starch hydrolase (except 4a2), and hydrogen cyanide production (except 4a2 and 1D). All the tested antagonists produced indole-3-acetic acid (13.4–39.0 μg mL–1), solubilized inorganic phosphate (75–103 μg mL–1), and produced siderophores (17.1–23.7%) in vitro. All the tested bacterial isolates showed varying levels of susceptibility and resistance response against different antibiotics and all these bacterial isolates were found to be non-pathogenic to chili seeds and notably enhanced percentage seed germination, plumule, redical length, and vigor index over un-inoculated control. Additionally, under pathogen pressure, bacterization increased the defense related enzymes such as Peroxidase (PO), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activates. Moreover, the treatment of chili seeds with these bacterial isolates significantly suppressed the damping-off caused by P. myriotylum and improved PGP traits compared to the control. In addition, a positive correlation was noticed between shoot, root length, and dry shoot and root weight, and there was a negative correlation between dry shoot, root weight, and seedling percentage mortality. These results showed that native PGPR possesses multiple traits beneficial to the chili plants and can be used to develop eco-friendly and effective seed treatment formulation as an alternative to synthetic chemical fungicides.

scholarly journals Impact of Pseudomonas spp. on Plant Growth, Lytic Enzymes and Secondary Metabolites Production

2021 ◽  
Vol 3 ◽  
Author(s):  
Rajesh R. Waghunde ◽  
Ambalal N. Sabalpara
Keyword(s):  
Plant Growth ◽  
Acid Production ◽  
Plant Pathogens ◽  
Growth Promotion ◽  
Root Weight ◽  
Bacterial Strains ◽  
Lytic Enzymes ◽  
Acetic Acid Production ◽  
Metabolites Production

Seven strains of Pseudomonas spp. were isolated from the south Gujarat region of India. Antifungal and bacterial activities of bacterial strains were evaluated against important plant pathogens in vitro, among them, PaRS was found most effective. The indole acetic acid production was recorded in all isolated Pseudomonas spp. Seed treatment with PaRS at 6 g/kg was significantly superior over other treatments for plant growth promotion (germination, shoot and root length, shoot and root weight, vigor index, and both shoot and root colonization) under standard roll towel method and pot conditions. The maximum siderophore production was observed in PaRS and medium production in PfRB, PaNS, and PfNC. PaNS and PaRS strains recorded strong HCN production but moderate production recorded in PaWP, PaWS, and PfNC. The maximum phosphate solubalization zone (22 mm) was found in PaRS. PaRS recorded maximum chitinase, ß-1,3-glucanase activity, hydrogen cyanide, and salicylic acid production as compared to other strains.

scholarly journals Biological control of chili damping off disease, caused by Pythium myriotylum

2020 ◽  
Author(s):  
Sajjad Hyder ◽  
Amjad Shahzad Gondal ◽  
Zarrin Fatima Rizvi ◽  
Muhammad Irtaza Sajjad Haider ◽  
Muhammad Inam-ul-Haq
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Disease Suppression ◽  
Root Weight ◽  
Dual Culture ◽  
Bacterial Isolates ◽  
Damping Off ◽  
Pythium Myriotylum ◽  
Pgp Traits

ABSTRACTPythium myriotylum is a notorious soil-borne oomycete causes post-emergence damping off in chilli pepper. Of various disease management strategies, utilization of plant growth promoting rhizobacteria (PGPR) in disease suppression and plant growth promotion is eye catching strategy. The present study was performed to isolate and characterize PGPR indigenous to chili rhizosphere in Pakistan, and to test their potential to suppress damping off and plant growth promotion in chilli. Out of total 28 antagonists, 8 bacterial isolates (4a2, JHL-8, JHL-12, 1C2, RH-24, 1D, 5C and RH-87) significantly suppressed the colony growth of P. myriotylum in dual culture experiment. All the tested bacterial isolates were characterized for biochemical attributes, and 16S rRNA sequence based phylogenetic analysis identified these isolates as Flavobacterium spp., Bacillus megaterium, Pseudomonas putida, Bacillus cereus and Pseudomonas libanensis. All the tested bacterial isolates showed positive test results for ammonia production, starch hydrolase (except 4a2), and hydrogen cyanide production (except 4a2 and 1D). All the tested antagonists produced indole-3-acetic acid (13.4-39.0 μg ml−1), solubilized inorganic phosphate (75–103 μgml-1) and produced siderophores (17.1–23.7%) in vitro. All the tested bacterial isolates showed varied level of susceptibility and resistance response against different antibiotics and all these bacterial isolates were found non-pathogenic to chill seeds and notably enhanced percentage seed germination, plumule, redical length and vigor index over un-inoculated control. Additionally, under pathogen pressure, bacterization increased the defense related enzymes (PO, PPO and PAL) activates. Moreover, chilli seeds treatment with these bacterial isolates significantly suppressed damping-off caused by P. myriotylum, and improved PGP traits as compared to control. In addition, a positive correlation was noticed between shoot, root length and dry shoot and root weigh and a negative correlation was seen between dry shoot, root weight and seedling percentage mortality. These results showed that native PGPR possess multiple traits beneficial to the chilli plants and can be used to develop eco-friendly and effective seed treatment formulation as an alternative to synthetic chemical fungicides.

scholarly journals Isolation and Characterization of Plant Growth Promoting Rhizobacteria for Growth Promotion of Rice (Oryza sativa L.) and Wheat (Triticum aestivum)

2021 ◽  
Vol 2 (2) ◽  
pp. 177-194
Author(s):  
Muhammad Ayyaz ◽  
Zulqurnain Khan ◽  
Nabila Tabassam ◽  
Tariq Sultan ◽  
Amjad Saeed ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Plant Growth ◽  
Growth Promotion ◽  
Growth Parameters ◽  
Oryza Sativa L ◽  
Growth Enhancement ◽  
Root Weight ◽  
Bacterial Strains ◽  
Phosphorus Solubilization ◽  
Isolation And Characterization

The use of rhizobacteria for plant growth enhancement is decades old. Still, in this era of the 21st century, biofertilizers have become the need of the day due to the health and environmental concerns associated with chemical fertilizers and pesticides. Rhizobacteria strains were isolated from the rhizosphere of rice and wheat. The selected bacterial strains' nitrogen fixation, indole acetic acid (IAA) production, phosphorus solubilization, and antifungal activity were determined on morphological, biochemical, and molecular levels. Production of IAA ranged from 6 µg/ml to 29.33 µg/ml. Ethylene production (C2H4/hr) varied from 2 µmoles to 9.8 µmoles. Maximum Phosphorus Solubilization index (7), decrease in pH (4) and Solubilization % age (0.49) was observed in WM-2 (wheat microbe). Promising results were obtained concerning antifungal activity against Rhizoctonia solani and Fusarium sp. The effect of the potential PGPR strains on the germination of rice and wheat was significantly positive in Petri plates. In the case of rice, the highest shoot length (29.27 cm) was observed by inoculation with RPR-33 (Rice isolate), and the most increased root length (9.33 cm) was observed in the treatment inoculated with RPR-42. The highest shoot fresh weight (476.67 mg/plant) was recorded in the treatment inoculated with RPR-42. The maximum root weight was 170 mg/plant in the same treatment. For wheat, all recorded growth parameters were improved significantly by wheat microbe WM-5. All the PGPR isolates showed positive results for growth parameters of wheat and rice on inoculation. So, it is suggested that these PGPR isolates may be used in potential biofertilizers.

scholarly journals Diazotrophic Bacteria Pantoea dispersa and Enterobacter asburiae Promote Sugarcane Growth by Inducing Nitrogen Uptake and Defense-Related Gene Expression

2021 ◽  
Vol 11 ◽  
Author(s):  
Pratiksha Singh ◽  
Rajesh Kumar Singh ◽  
Hai-Bi Li ◽  
Dao-Jun Guo ◽  
Anjney Sharma ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Ethylene Production ◽  
Growth Promotion ◽  
Rrna Gene ◽  
N Fixation ◽  
Root Weight ◽  
Related Gene ◽  
Pantoea Dispersa ◽  
Enterobacter Asburiae

Sugarcane is a major crop in tropical and subtropical regions of the world. In China, the application of large amounts of nitrogen (N) fertilizer to boost sugarcane yield is commonplace, but it causes substantial environmental damages, particularly soil, and water pollution. Certain rhizosphere microbes are known to be beneficial for sugarcane production, but much of the sugarcane rhizosphere microflora remains unknown. We have isolated several sugarcane rhizosphere bacteria, and 27 of them were examined for N-fixation, plant growth promotion, and antifungal activity. 16S rRNA gene sequencing was used to identify these strains. Among the isolates, several strains were found to have a relatively high activity of nitrogenase and ACC deaminase, the enzyme that reduces ethylene production in plants. These strains were found to possess nifH and acdS genes associated with N-fixation and ethylene production, respectively. Two of these strains, Pantoea dispersa-AA7 and Enterobacter asburiae-BY4 showed maximum plant growth promotion (PGP) and nitrogenase activity, and thus they were selected for detailed analysis. The results show that they colonize different sugarcane tissues, use various growth substrates (carbon and nitrogen), and tolerate various stress conditions (pH and osmotic stress). The positive effect of AA7 and BY4 strains on nifH and stress-related gene (SuCAT, SuSOD, SuPAL, SuCHI, and SuGLU) expression and the induction of defense-related processes in two sugarcane varieties, GT11 and GXB9, showed their potential for stress amelioration and PGP. Both bacterial strains increased several sugarcane physiological parameters. i.e., plant height, shoot weight, root weight, leaf area, chlorophyll content, and photosynthesis, in plants grown under greenhouse conditions. The ability of rhizobacteria on N-fixing in sugarcane was also confirmed by a 15N isotope-dilution study, and the estimate indicates a contribution of 21–35% of plant nitrogen by rhizobacterial biological N fixation (BNF). This is the first report of sugarcane growth promotion by N-fixing rhizobacteria P. dispersa and E. asburiae strains. Both strains could be used as biofertilizer for sugarcane to minimize nitrogen fertilizer use and better disease management.

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