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Prihatna C, Yan Q. Exopolysaccharide is required by Paraburkholderia phytofirmans PsJN to confer drought-stress tolerance in pea. Front Microbiol 2024; 15:1442001. [PMID: 39184028 PMCID: PMC11341992 DOI: 10.3389/fmicb.2024.1442001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2024] [Accepted: 07/30/2024] [Indexed: 08/27/2024] Open
Abstract
Paraburkholderia phytofirmans PsJN is a plant symbiotic bacterium that can colonize a broad spectrum of plant hosts and frequently shows beneficial effects on plant growth. Exopolysaccharide (EPS) is known to be important in plant-bacteria interactions. Previously, we reported that EPS is required for PsJN to survive from drought stress and colonize in pea (Pisum sativum) under drought condition. However, whether EPS is necessary for PsJN to promote plant growth remains unknown. In this work, a comparative study was conducted between the wild-type PsJN and its ∆bceQ mutant that lacks EPS to investigate the role of EPS in PsJN to confer drought-stress tolerance on pea plant. Our results showed that wild type PsJN, but not the ∆bceQ mutant, promoted pea seed germination and seedlings growth under drought stress. Pea plants inoculated with the wild type PsJN had a higher level of drought tolerance, as shown by a better vegetative growth and enhanced nodule formation, than plants inoculated with the ∆bceQ mutant. Moreover, EPS plays a role in the plant colonization under drought stress, because the ∆bceQ mutant was unable to colonize pea seeds and roots as effectively as the wild type PsJN. Further, expression of the EPS biosynthesis genes in the bceOVN operon of the wild type PsJN was induced by the presence of glucose. Overall, this study demonstrated that PsJN can promote pea plant growth under drought conditions and EPS is required for PsJN to confer beneficial effects to host plant.
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Affiliation(s)
| | - Qing Yan
- Plant Sciences and Plant Pathology Department, Montana State University, Bozeman, MT, United States
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Monaco P, Baldoni A, Naclerio G, Scippa GS, Bucci A. Impact of Plant-Microbe Interactions with a Focus on Poorly Investigated Urban Ecosystems-A Review. Microorganisms 2024; 12:1276. [PMID: 39065045 PMCID: PMC11279295 DOI: 10.3390/microorganisms12071276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 07/28/2024] Open
Abstract
The urbanization process, which began with the Industrial Revolution, has undergone a considerable increase over the past few decades. Urbanization strongly affects ecological processes, often deleteriously, because it is associated with a decrease in green spaces (areas of land covered by vegetation), loss of natural habitats, increased rates of species extinction, a greater prevalence of invasive and exotic species, and anthropogenic pollutant accumulation. In urban environments, green spaces play a key role by providing many ecological benefits and contributing to human psychophysical well-being. It is known that interactions between plants and microorganisms that occur in the rhizosphere are of paramount importance for plant health, soil fertility, and the correct functioning of plant ecosystems. The growing diffusion of DNA sequencing technologies and "omics" analyses has provided increasing information about the composition, structure, and function of the rhizomicrobiota. However, despite the considerable amount of data on rhizosphere communities and their interactions with plants in natural/rural contexts, current knowledge on microbial communities associated with plant roots in urban soils is still very scarce. The present review discusses both plant-microbe dynamics and factors that drive the composition of the rhizomicrobiota in poorly investigated urban settings and the potential use of beneficial microbes as an innovative biological tool to face the challenges that anthropized environments and climate change impose. Unravelling urban biodiversity will contribute to green space management, preservation, and development and, ultimately, to public health and safety.
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Affiliation(s)
- Pamela Monaco
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy; (A.B.); (G.N.); (G.S.S.)
| | | | | | | | - Antonio Bucci
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Italy; (A.B.); (G.N.); (G.S.S.)
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Adan IH, Asudi GO, Niassy S, Jalloh AA, Mutua JM, Chidawanyika F, Khamis F, Khan Z, Subramanian S, Dubois T, Mutyambai DM. Comparative microbiome diversity in root-nodules of three Desmodium species used in push-pull cropping system. Front Microbiol 2024; 15:1395811. [PMID: 38966391 PMCID: PMC11222577 DOI: 10.3389/fmicb.2024.1395811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/28/2024] [Indexed: 07/06/2024] Open
Abstract
Background Desmodium species used as intercrops in push-pull cropping systems are known to repel insect-pests, suppress Striga species weeds, and shift soil microbiome. However, the mechanisms through which Desmodium species impact the soil microbiome, either through its root exudates, changes in soil nutrition, or shading microbes from its nodules into the rhizosphere, are less understood. Here, we investigated the diversity of root-nodule microbial communities of three Desmodium species- Desmodium uncinatum (SLD), Desmodium intortum (GLD), and Desmodium incanum (AID) which are currently used in smallholder maize push-pull technology (PPT). Methods Desmodium species root-nodule samples were collected from selected smallholder farms in western Kenya, and genomic DNA was extracted from the root-nodules. The amplicons underwent paired-end Illumina sequencing to assess bacterial and fungal populations. Results We found no significant differences in composition and relative abundance of bacterial and fungal species within the root-nodules of the three Desmodium species. While a more pronounced shift was observed for fungal community compositions compared to bacteria, no significant differences were observed in the general diversity (evenness and richness) of fungal and bacterial populations among the three Desmodium species. Similarly, beta diversity was not significantly different among the three Desmodium species. The root-nodule microbiome of the three Desmodium species was dominated by Bradyrhizobium and Fusarium species. Nevertheless, there were significant differences in the proportion of marker gene sequences responsible for energy and amino acid biosynthesis among the three Desmodium species, with higher sequence proportions observed in SLD. Conclusion There is no significant difference in the microbial community of the three Desmodium species used in PPT. However, root-nodule microbiome of SLD had significantly higher marker gene sequences responsible for energy and amino acid biosynthesis. Therefore, it is likely that the root-nodules of the three Desmodium species host similar microbiomes and influence soil health, consequently impacting plant growth and agroecosystem functioning.
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Affiliation(s)
- Isack H. Adan
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, Nairobi, Kenya
| | - George Ochieng Asudi
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, Nairobi, Kenya
| | - Saliou Niassy
- Inter-African Phytosanitary Council of the African Union, Yaoundé, Cameroon
| | - Abdul A. Jalloh
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | | | - Frank Chidawanyika
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Zoology and Entomology, University of Free State, Bloemfontein, South Africa
| | - Fathiya Khamis
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Zeyaur Khan
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Thomas Dubois
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Daniel Munyao Mutyambai
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Life Science, South Eastern Kenya University, Kitui, Kenya
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Dove R, Wolfe ER, Stewart NU, Coleman A, Chavez SH, Ballhorn DJ. Root nodules of red alder (Alnus rubra) and sitka alder (Alnus viridis ssp. sinuata) are inhabited by taxonomically diverse cultivable microbial endophytes. Microbiologyopen 2024; 13:e1422. [PMID: 38847331 PMCID: PMC11157421 DOI: 10.1002/mbo3.1422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 05/27/2024] [Accepted: 05/29/2024] [Indexed: 06/10/2024] Open
Abstract
The root nodules of actinorhizal plants are home to nitrogen-fixing bacterial symbionts, known as Frankia, along with a small percentage of other microorganisms. These include fungal endophytes and non-Frankia bacteria. The taxonomic and functional diversity of the microbial consortia within these root nodules is not well understood. In this study, we surveyed and analyzed the cultivable, non-Frankia fungal and bacterial endophytes of root nodules from red and Sitka alder trees that grow together. We examined their taxonomic diversity, co-occurrence, differences between hosts, and potential functional roles. For the first time, we are reporting numerous fungal endophytes of alder root nodules. These include Sporothrix guttuliformis, Fontanospora sp., Cadophora melinii, an unclassified Cadophora, Ilyonectria destructans, an unclassified Gibberella, Nectria ramulariae, an unclassified Trichoderma, Mycosphaerella tassiana, an unclassified Talaromyces, Coniochaeta sp., and Sistotrema brinkmanii. We are also reporting several bacterial genera for the first time: Collimonas, Psychrobacillus, and Phyllobacterium. Additionally, we are reporting the genus Serratia for the second time, with the first report having been recently published in 2023. Pseudomonas was the most frequently isolated bacterial genus and was found to co-inhabit individual nodules with both fungi and bacteria. We found that the communities of fungal endophytes differed by host species, while the communities of bacterial endophytes did not.
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Affiliation(s)
- Robyn Dove
- Portland State University Biology DepartmentPortlandOregonUSA
| | - Emily R. Wolfe
- Portland State University Biology DepartmentPortlandOregonUSA
- Portland State UniversityPortlandOregonUSA
| | - Nathan U. Stewart
- Portland State University Biology DepartmentPortlandOregonUSA
- Portland State UniversityPortlandOregonUSA
| | - Abigail Coleman
- Portland State University Biology DepartmentPortlandOregonUSA
- Oregon Health and Science UniversityPortlandOregonUSA
| | - Sara Herrejon Chavez
- Portland State University Biology DepartmentPortlandOregonUSA
- University of California BerkeleyBerkeleyCaliforniaUSA
| | - Daniel J. Ballhorn
- Portland State University Biology DepartmentPortlandOregonUSA
- Portland State UniversityPortlandOregonUSA
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Xue X, Chen R, Xu C, Zhang C, Dong L, Zhao X, Wang X. Apple-marigold intercropping improves soil properties by changing soil metabolomics and bacterial community structures. Front Microbiol 2023; 14:1195985. [PMID: 37455738 PMCID: PMC10343436 DOI: 10.3389/fmicb.2023.1195985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023] Open
Abstract
Marigold can protect crops against soil-borne diseases. However, the effects of intercropping with marigold on apple rhizosphere soils are not known. In this study, we investigated the metabolite profiles and bacterial community structures in rhizosphere soils of the apple-marigold intercropping system by high-throughput sequencing and soil metabolomics. The results show that intercropping marigold could significantly enhance soil moisture, nitrogen, and enzyme activities compared with clean tillage. The soil metabolite profiles and the soil bacterial community structures in the rhizosphere soils were different between the inter-and mono-cropping systems. Among nine metabolites, carbohydrates were more increased in the intercropping system than in the monocropping system. Pathway enrichment analysis revealed that the greatest differential, in terms of metabolic pathway, was starch and sucrose metabolism. Moreover, intercropping marigold significantly increased the relative abundance of plant growth promoting bacteria in rhizosphere soils, such as Rhizobiales, Pseudomonadales, and Bacillales. These results indicate that marigold intercropping positively affected the apple orchard's soil quality and may provide a new intercropping technique to improve soil fertility in orchards and promote plant growth.
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Affiliation(s)
- Xiaomin Xue
- Shandong Institute of Pomology, Tai’an, China
| | - Ru Chen
- Shandong Institute of Pomology, Tai’an, China
| | - Chao Xu
- School of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | | | - Lijuan Dong
- Taishan Forestry Research Institute, Tai’an, China
| | - Xianyan Zhao
- School of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Xiaohan Wang
- School of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
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Safronova V, Sazanova A, Belimov A, Guro P, Kuznetsova I, Karlov D, Chirak E, Yuzikhin O, Verkhozina A, Afonin A, Tikhonovich I. Synergy between Rhizobial Co-Microsymbionts Leads to an Increase in the Efficiency of Plant-Microbe Interactions. Microorganisms 2023; 11:1206. [PMID: 37317180 DOI: 10.3390/microorganisms11051206] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/24/2023] [Accepted: 05/02/2023] [Indexed: 06/16/2023] Open
Abstract
Combined inoculation of legumes with rhizobia and plant growth-promoting rhizobacteria or endophytes is a known technique for increasing the efficiency of nitrogen-fixing symbiosis and plant productivity. The aim of this work was to expand knowledge about the synergistic effects between commercial rhizobia of pasture legumes and root nodule bacteria of relict legume species. Pot experiments were performed on common vetch (Vicia sativa L.) and red clover (Trifolium pratense L.) co-inoculated with the participation of the corresponding commercial rhizobial strains (R. leguminosarum bv. viciae RCAM0626 and R. leguminosarum bv. trifolii RCAM1365) and seven strains isolated from nodules of relict legumes inhabiting the Baikal Lake region and the Altai Republic: Oxytropis popoviana, Astragalus chorinensis, O. tragacanthoides and Vicia costata. The inoculation of plants with combinations of strains (commercial strain plus the isolate from relict legume) had a different effect on symbiosis depending on the plant species: the increase in the number of nodules was mainly observed on vetch, whereas increased acetylene reduction activity was evident on clover. It was shown that the relict isolates differ significantly in the set of genes related to different genetic systems that affect plant-microbe interactions. At the same time, they had additional genes that are involved in the formation of symbiosis and determine its effectiveness, but are absent in the used commercial strains: symbiotic genes fix, nif, nod, noe and nol, as well as genes associated with the hormonal status of the plant and the processes of symbiogenesis (acdRS, genes for gibberellins and auxins biosynthesis, genes of T3SS, T4SS and T6SS secretion systems). It can be expected that the accumulation of knowledge about microbial synergy on the example of the joint use of commercial and relict rhizobia will allow in the future the development of methods for the targeted selection of co-microsymbionts to increase the efficiency of agricultural legume-rhizobia systems.
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Affiliation(s)
- Vera Safronova
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Anna Sazanova
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Andrey Belimov
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Polina Guro
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Irina Kuznetsova
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Denis Karlov
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Elizaveta Chirak
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Oleg Yuzikhin
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Alla Verkhozina
- Siberian Institute of Plant Physiology and Biochemistry (SIPPB), P.O. Box 1243, 664033 Irkutsk, Russia
| | - Alexey Afonin
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
| | - Igor Tikhonovich
- All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Sh. Podbelskogo 3, 196608 St. Petersburg, Russia
- Department of Genetics and Biotechnology, Saint Petersburg State University, Universitetskaya Emb. 7/9, 199034 St. Petersburg, Russia
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Evaluation of inorganic phosphate solubilizing efficiency and multiple plant growth promoting properties of endophytic bacteria isolated from root nodules Erythrina brucei. BMC Microbiol 2022; 22:276. [PMCID: PMC9675159 DOI: 10.1186/s12866-022-02688-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 11/02/2022] [Indexed: 11/21/2022] Open
Abstract
Background In soils, phosphorous (P) mostly exists in fixed/insoluble form and unavailable for plants use in soil solution, hence it is in scarcity. P is fixed in the form of aluminium, iron and manganese phosphates in acidic soils and calcium phosphate in alkaline soils. Phosphate solubilizing bacteria, the ecological engineers play a pivotal role in the mobilization of fixed forms of P by using different mechanisms. The objectives of this study were to evaluate inorganic phosphate solubilizing efficiency and other multiple plant growth promoting traits of Erythrina brucei root nodule endophytic bacteria and to investigate effects of the selected endophytic bacteria on the growth of wheat plant under phosphorous deficient sand culture at greenhouse conditions. Results Among a total of 304 passenger endophytic bacteria, 119 (39%) exhibited tricalcium phosphate (TCP) solubilization; however, none of them were formed clear halos on solid medium supplemented with aluminum phosphate (Al-P) or iron phosphate (Fe–P). Among 119 isolates, 40% exhibited IAA production. The selected nine potential isolates also exhibited potentials of IAA, HCN, NH3 and/or hydrolytic enzymes production. All the selected isolates were potential solubilizers of the three inorganic phosphates (Al-P, Fe–P and TCP) included in liquid medium. The highest values of solubilized TCP were recorded by isolates AU4 and RG6 (A. soli), 108.96 mg L−1 and 107.48 mg L−1, respectively at sampling day3 and 120.36 mg L−1 and 112.82 mg L−1, respectively at day 6. The highest values of solubilized Al-P and Fe–P were recorded by isolate RG6, 102.14 mg L−1 and 96.07 mg L−1, respectively at sampling days 3 and 6, respectively. The highest IAA, 313.61 µg mL−1 was recorded by isolate DM17 (Bacillus thuringiensis). Inoculation of wheat with AU4, RG6 and RG5 (Acinetobacter soli) increased shoot length by 11, 17.4 and 14.6%, respectively compared to the negative control. Similarly, 76.9, 69.2 and 53.8% increment in shoot dry weight is recorded by inoculation with RG6, AU4 and RG5, respectively. These nine potential endophytic isolates are identified to Gluconobacter cerinus (4), Acinetobacter soli (3), Achromobacter xylosoxidans (1) and Bacillus thuringiensis (1). Conclusion AU4, RG6 and RG5 can be potential bio-inoculants candidates as low cost agricultural inputs in acidic and/or alkaline soils for sustainable crop production. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02688-7.
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Sai Aparna Devi N, Balachandar D. Authentication of putative competitive bacterial endophytes of rice by re-isolation and DNA fingerprinting assay. J Appl Microbiol 2022; 133:1808-1820. [PMID: 35751483 DOI: 10.1111/jam.15689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 03/30/2022] [Accepted: 06/22/2022] [Indexed: 11/26/2022]
Abstract
AIM The plant-growth-promoting putative competitive endophytes offer significant benefits to sustainable agriculture. The unworthy opportunistic and passenger endophytes are inevitable during the isolation of putative competitive endophytes. This study aimed to discriminate the putative competitive endophytes undoubtedly from the opportunistic and passenger endophytes. METHODS AND RESULTS The newly-isolated endophytes from field-grown rice were inoculated to 5-days old rice seedlings under gnotobiotic conditions. Re-isolation of the inoculated strains from the root surface, inner tissues of the whole plant, root, and shoot was performed after 5-days. All the re-isolated colonies were compared with native isolate for the homology by BOX-A1R-based repetitive extragenic palindromic-PCR (BOX-PCR) and enterobacterial repetitive intergenic consensus (ERIC-PCR) DNA fingerprints. The results revealed that the putative competitive endophyte (RE25 and RE10) showed positive for re-isolation and BOX and ERIC fingerprints for the whole plant, root, and shoot. The opportunistic (RE27 and RE8) and passenger endophytes (RE44 and RE18) failed in re-isolation either from root or shoot. The epiphytes (ZSB15 and Az204) showed negative for endophytic re-isolation and positive for surface colonization. CONCLUSION This modified procedure can discriminate the putative competitive endophytes from others. SIGNIFICANCE AND IMPACT OF THE STUDY Eliminating the opportunistic and passenger endophytes and epiphytes early by this method would help develop endophytic inoculants to enhance rice productivity.
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Affiliation(s)
- Nunna Sai Aparna Devi
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
| | - Danajeyan Balachandar
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
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