Browsing by Author "Ashutosh Kumar Rai"

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Arbuscular mycorrhizal fungi as a potential biofertilizers for agricultural sustainability
(Open Science Publishers LLP Inc., 2022) Kumar Anand; Gaurav Kumar Pandey; Tanvir Kaur; Olivia Pericak; Collin Olson; Rajinikanth Mohan; Kriti Akansha; Ashok Yadav; Rubee Devi; Divjot Kour; Ashutosh Kumar Rai; Manish Kumar; Ajar Nath Yadav
Globally, by 2050, agricultural food production will be increased to feed the growing population. To achieve the objective in sustainable manner, scientific chronicles have explores the mutualistic interaction between plant roots and rhizosphere microbiome. One of the interactions of plants roots was found with arbuscular mycorrhiza fungi (AMF), a rhizosphere microbiome. Biofertilization process by the mean of AMF has depicted as a beneficial alternative to chemical fertilization practices. It has been recognized for having several potential applications such as plant fertilization (phosphorus, nitrogen and other micronutrients), alleviation of biotic (protecting plants from pest and pathogens), and abiotic stresses (drought, salinity, heavy metals, low and high temperature). AMF sustainably increases the plant growth and production by establishing within the host root with the help of set of genes and fulfilling the needs of the host. At present, worldwide total 340 species of AMF has been found. In the present review, global diversity, molecular crosstalk in AMF symbiosis and their potential application in sustainable agriculture has been reviewed. © 2022 Anand, et al.
Biodiversity, mechanisms, and potential biotechnological applications of minerals solubilizing extremophilic microbes: A review
(Open Science Publishers LLP Inc., 2024) Rubee Devi; Tanvir Kaur; Rajeshwari Negi; Babita Sharma; Sohini Chowdhury; Monit Kapoor; Sangram Singh; Sarvesh Rustagi; Sheikh Shreaz; Pankaj Kumar Rai; Ashutosh Kumar Rai; Ashok Yadav; Divjot Kour; Ajar Nath Yadav
The earth’s surface consists of arid, semi-arid, and hyper-arid lands, where life is profoundly challenged by harsh conditions such as temperature fluctuations, water scarcity, high levels of solar radiations, and soil salinity. The harsh environmental conditions pose serious consequences on plant survival, growth, and productivity accessibility of nutrients reduces. To cope with the harsh environments and increase plant productivity, an extremophilic microbe has attracted agriculturists and environmentalists. The extremophilic microbes, adapted to extreme environmental conditions, offer an unexploited reservoir for biofertilizers, which could provide various forms of nutrients and alleviate the stress caused by the abiotic factors in an environment friendly manner. Worldwide, minerals solubilizing extremophilic microbes are distributed in various hotspots and belong to three domains of life including, archaea, bacteria, and eukarya. The minerals solubilizing extremophilic microbes belongs to diverse phyla, namely, Ascomycota, Actinobacteria, Basidiomycota, Bacteroidetes, Crenarchaeota, Deinococcus-Thermus, Euryarchaeota, Firmicutes, and Proteobacteria. Mineral solubilizing extremophilic microbes achieve the mineral solubilization of phosphorus, potassium, zinc, and selenium by secreting special compounds such as organic acid, exopolysaccharides, and different enzymes. Consequently, extremophilic microbes are becoming increasingly important in agriculture, industries and environmental biotechnology as well, paving the way for novel sequencing technologies and “metaomics” methods, including metagenomics, metatranscriptomics, and metaproteomics. The extremophilic microbial diversity and their biotechnological application in agriculture and industrial applications will be a milestone for future needs. The present review deals with biodiversity, mechanisms and potential biotechnological applications of minerals solubilizing extremophilic microbes. © 2024 Rubee Devi, et al.
Bioformulation of mineral solubilizing microbes as novel microbial consortium for the growth promotion of wheat (Triticum aestivum) under the controlled and natural conditions
(Elsevier Ltd, 2024) Rubee Devi; Tanvir Kaur; Rajeshwari Negi; Divjot Kour; Sanjeev Kumar; Ashok Yadav; Sangram Singh; Kundan Kumar Chaubey; Ashutosh Kumar Rai; Sheikh Shreaz; Ajar Nath Yadav
Microbes are a worthwhile organism of the earth that could be formulated as consortium which can be utilized as biofertilizers. Consortium-based bioinoculants or biofertilizers are superior to single strain-based inoculants for sustainable agricultural productivity and increased micronutrient content in yield. The aim of present study was to evaluate the effect of different combinations of beneficial bacteria that are more effective than single-based bioinoculants. The current work focuses on the isolation of rhizospheric microorganisms from various cereals and pseudocereal crops and the development of a single inoculum as well as a bacterial consortium which were evaluated on wheat crop. A total 214 rhizospheric bacteria were sorted out and, screened for mineral solubilizing attributes i.e., phosphorus, potassium, zinc and selenium solubilization. Among all the bacterial isolates, four potential strains exhibiting P, K, Zn and Se-solubilizing attributes were identified with the help of 16S rRNA gene sequencing as Rahnella aquatilis EU-A3Rb1, Erwinia aphidicola EU-A2RNL1, Brevibacillus brevis EU-C3SK2, and Bacillus mycoides EU-WRSe4, respectively. The identified strains formulated as a consortium which were found to improve the plant growth and physiological parameters in comparison to single culture inoculants and control. To the best of our knowledge, the present investigation is the first report that has developed the consortium from bacterial strains Rahnella aquatilis EU-A3Rb1, Erwinia aphidicola EU-A2RNL1, Brevibacillus brevis EU-C3SK2, and Bacillus mycoides EU-WRSe4. A combination of bacterial strains could be used as liquid inoculants for cereal crops growing in mountainous regions. © 2024
Carotenoid biosynthetic pathways are regulated by a network of multiple cascades of alternative sigma factors in Azospirillum brasilense Sp7
(American Society for Microbiology, 2016) Ashutosh Kumar Rai; Ashutosh Prakash Dubey; Santosh Kumar; Debashis Dutta; Mukti Nath Mishra; Bhupendra Narain Singh; Anil Kumar Tripathi
Carotenoids constitute an important component of the defense system against photooxidative stress in bacteria. In Azospirillum brasilense Sp7, a nonphotosynthetic rhizobacterium, carotenoid synthesis is controlled by a pair of extracytoplasmic function sigma factors (RpoEs) and their cognate zinc-binding anti-sigma factors (ChrRs). Its genome harbors two copies of the gene encoding geranylgeranyl pyrophosphate synthase (CrtE), the first critical step in the carotenoid biosynthetic pathway in bacteria. Inactivation of each of two crtE paralogs found in A. brasilense caused reduction in carotenoid content, suggesting their involvement in carotenoid synthesis. However, the effect of crtE1 deletion was more pronounced than that of crtE2 deletion. Out of the five paralogs of rpoH in A. brasilense, overexpression of rpoH1 and rpoH2 enhanced carotenoid synthesis. Promoters of crtE2 and rpoH2 were found to be dependent on RpoH2 and RpoE1, respectively. Using a two-plasmid system in Escherichia coli, we have shown that the crtE2 gene of A. brasilense Sp7 is regulated by two cascades of sigma factors: one consisting of RpoE1and RpoH2 and the other consisting of RpoE2 and RpoH1. In addition, expression of crtE1 was upregulated indirectly by RpoE1 and RpoE2. This study shows, for the first time in any carotenoid-producing bacterium, that the regulation of carotenoid biosynthetic pathway involves a network of multiple cascades of alternative sigma factors. © 2016, American Society for Microbiology. All Rights Reserved.
Catalase expression in Azospirillum brasilense Sp7 is regulated by a network consisting of OxyR and two RpoH paralogs and including an RpoE1→RpoH5 regulatory cascade
(American Society for Microbiology, 2018) Ashutosh Kumar Rai; Sudhir Singh; Sushil Kumar Dwivedi; Amit Srivastava; Parul Pandey; Santosh Kumar; Bhupendra Narain Singh; Anil Kumar Tripathi
The genome of Azospirillum brasilense encodes five RpoH sigma factors: two OxyR transcription regulators and three catalases. The aim of this study was to understand the role they play during oxidative stress and their regulatory interconnection. Out of the 5 paralogs of RpoH present in A. brasilense, inactivation of only rpoH1 renders A. brasilense heat sensitive. While transcript levels of rpoH1 were elevated by heat stress, those of rpoH3 and rpoH5 were upregulated by H2O2. Catalase activity was upregulated in A. brasilense and its rpoH::km mutants in response to H2O2 except in the case of the rpoH5::km mutant, suggesting a role for RpoH5 in regulating inducible catalase. Transcriptional analysis of the katN, katAI, and katAII genes revealed that the expression of katN and katAII was severely compromised in the rpoH3::km and rpoH5::km mutants, respectively. Regulation of katN and katAII by RpoH3 and RpoH5, respectively, was further confirmed in an Escherichia coli twoplasmid system. Regulation of katAII by OxyR2 was evident by a drastic reduction in growth, KatAII activity, and katAII::lacZ expression in an oxyR2::km mutant. This study reports the involvement of RpoH3 and RpoH5 sigma factors in regulating oxidative stress response in alphaproteobacteria. We also report the regulation of an inducible catalase by a cascade of alternative sigma factors and an OxyR. Out of the three catalases in A. brasilense, those corresponding to katN and katAII are regulated by RpoH3 and RpoH5, respectively. The expression of katAII is regulated by a cascade of RpoE1→RpoH5 and OxyR2. © 2018 American Society for Microbiology.
COVID-19: Impact on linguistic and genetic isolates of India
(Springer Nature, 2022) Prajjval Pratap Singh; Prashanth Suravajhala; Chandana Basu Mallick; Rakesh Tamang; Ashutosh Kumar Rai; Pratheusa Machha; Royana Singh; Abhishek Pathak; Vijay Nath Mishra; Pankaj Shrivastava; Keshav K. Singh; Kumarasamy Thangaraj; Gyaneshwer Chaubey
The rapid expansion of coronavirus SARS-CoV-2 has impacted various ethnic groups all over the world. The burden of infectious diseases including COVID-19 are generally reported to be higher for the Indigenous people. The historical knowledge have also suggested that the indigenous populations suffer more than the general populations in the pandemic. Recently, it has been reported that the indigenous groups of Brazil have been massively affected by COVID-19. Series of studies have shown that many of the indigenous communities reached at the verge of extinction due to this pandemic. Importantly, South Asia also has several indigenous and smaller communities, that are living in isolation. Till date, despite the two consecutive waves in India, there is no report on the impact of COVID-19 for indigenous tribes. Since smaller populations experiencing drift may have greater risk of such pandemic, we have analysed Runs of Homozygosity (ROH) among South Asian populations and identified several populations with longer homozygous segments. The longer runs of homozygosity at certain genomic regions may increases the susceptibility for COVID-19. Thus, we suggest extreme careful management of this pandemic among isolated populations of South Asia. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.
Effect of indigenous mineral availing microbial consortia and cattle manure combination for growth of maize (Zea mays L.)
(Springer, 2024) Rubee Devi; Marwa Fadhil Alsaffar; Duraid K.A. AL-Taey; Sanjeev Kumar; Rajeshwari Negi; Babita Sharma; Sangram Singh; Ashutosh Kumar Rai; Sarvesh Rustagi; Ashok Yadav; Tanvir Kaur; Divjot Kour; Ajar Nath Yadav; Amrik Singh Ahluwalia
Plant growth promoting bacterial strains were used as bioinoculants on cereal crops to improve plant growth and plant productivity. Crop responses to inoculation are complex because bacteria are not compatible with each other. Therefore, it is necessary to increase our understanding of the microbial ecology of crop rhizosphere under various agricultural techniques. In tropical agriculture, cattle manure is used as an organic fertilizer to increase soil fertility, however use of microbes as consortium have found as sustainable method for the enhancement of crops productivity. The purpose of this study was to evaluate the effects of three potential plant growth-promoting rhizospheric and endophytic bacterial strains EU-C3ST.R1, IARI-JR-44, and IARI-S-45 and organic fertilizers (cattle manure) individually and as consortia on maize (Zea mays L.) under both in-vitro and in-vivo conditions. A total of 123 bacterial strains were sorted out and screened for nitrogen fixation, phosphorus, and potassium solubilization. The potential N2-fixing; P and K solubilizing bacterial strains were identified using 16 S rRNA gene sequencing as Pseudomonas sp. EU-C3ST.R1, Micrococcus indicus IARI-JR-44, and Bacillus horikoshii IARI-S-45 respectively. The inoculation of these three strains on maize as microbial consortium and individual inoculum significantly increased the growth characteristic including height and biomass of the plants, as well as physiological characteristics i.e., chlorophyll, carotenoids, flavonoids, phenolics, and total soluble sugar content of the plant with respect to chemical fertilizers, cattle manure, and untreated control plant. The consortia were found to be more effective with respect to individual inoculants, cattle manure, and uninoculated control plants, so it can be utilized as biofertilizers for inoculation of cereal crops growing in hilly regions. © The Author(s) under exclusive licence to Society for Plant Research 2024.
Effect of indigenous mineral availing microbial consortia and cattle manure combination for growth of maize (Zea mays L.)
(Springer, 2025) Rubee Devi; Marwa Fadhil Fadhil Alsaffar; Duraid K.A. Altaey; Sanjeev Kumar; Rajeshwari Negi; Babita Sharma; Sangram N. Singh; Ashutosh Kumar Rai; Sarvesh Rustagi; Ashok Yadav; Tanvir Kaur; Divjot KOUR; Ajar Nath Yadav; Amrik Singh Ahluwalia
Plant growth promoting bacterial strains were used as bioinoculants on cereal crops to improve plant growth and plant productivity. Crop responses to inoculation are complex because bacteria are not compatible with each other. Therefore, it is necessary to increase our understanding of the microbial ecology of crop rhizosphere under various agricultural techniques. In tropical agriculture, cattle manure is used as an organic fertilizer to increase soil fertility, however use of microbes as consortium have found as sustainable method for the enhancement of crops productivity. The purpose of this study was to evaluate the effects of three potential plant growth-promoting rhizospheric and endophytic bacterial strains EU-C3ST.R1, IARI-JR-44, and IARI-S-45 and organic fertilizers (cattle manure) individually and as consortia on maize (Zea mays L.) under both in-vitro and in-vivo conditions. A total of 123 bacterial strains were sorted out and screened for nitrogen fixation, phosphorus, and potassium solubilization. The potential N2-fixing; P and K solubilizing bacterial strains were identified using 16 S rRNA gene sequencing as Pseudomonas sp. EU-C3ST.R1, Micrococcus indicus IARI-JR-44, and Bacillus horikoshii IARI-S-45 respectively. The inoculation of these three strains on maize as microbial consortium and individual inoculum significantly increased the growth characteristic including height and biomass of the plants, as well as physiological characteristics i.e., chlorophyll, carotenoids, flavonoids, phenolics, and total soluble sugar content of the plant with respect to chemical fertilizers, cattle manure, and untreated control plant. The consortia were found to be more effective with respect to individual inoculants, cattle manure, and uninoculated control plants, so it can be utilized as biofertilizers for inoculation of cereal crops growing in hilly regions. © The Author(s) under exclusive licence to Society for Plant Research 2024.
Endophytic nitrogen-fixing bacteria: Untapped treasurer for agricultural sustainability
(Open Science Publishers LLP Inc., 2023) Kusam Lata Rana; Divjot Kour; Tanvir Kaur; Rajeshwari Negi; Rubee Devi; Neelam Yadav; Pankaj Kumar Rai; Sangram Singh; Ashutosh Kumar Rai; Ashok Yadav; R.Z. Sayyed; Ajar Nath Yadav
Nitrogen (N) is one of the vital elements required for proper growth and development of plants. In the earth’s atmosphere, N is available in the form of nitrogen gas (N2) and mostly plants utilize N in the form nitrate (NO3-) and ammonium ion (NH4+) which are fixed through the biological process known as N2 fixation. As N is one of the elements most likely to be limiting to plant growth, this phenomenon provides an alternative to the implementations of chemical fertilizers as source of nutrients which have resulted in the ammonia volatilization, leading to significant impact on global warming in the atmosphere which, further, diverts the focus of scientist to find out eco-friendly technology. Globally, the demand for introducing eco-friendly practices for improving sustainable agriculture productivity has been increased. Since long time, microbes play an important role in providing pollution-free environment. Endophytic microbes being present inside the specific tissues of plants mostly empower in the growth of plants. The endophytic nitrogen-fixing microbe has been well characterized from leguminous as well non-legume crops. Endophytic bacteria belong to different phyla such as Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. The predominant N2-fixing endophytic Burkholderia, Rhizobium, Pseudomonas, Bradyrhizobium, Bacillus, Frankia, Enterobacter, and Azospirillum have been reported from different host plant. Nitrogen-fixing endophytic bacteria has a wide variety of application for maintaining growth of plant, crop yield, and health of soil for sustainable agriculture. The present review focuses on major developments on biodiversity of N-fixing endophytic microbiomes and their role for plant growth promotion and soil health for agroenvironmental sustainability. © 2023 Kusam Lata Rana, et al.
Fungi as an unseen heritage and wealth: Conclusion and future challenges
(Elsevier, 2024) Ajar Nath Yadav; Tanvir Kaur; Rubee Devi; Rajeshwari Negi; Divjot Kour; Ashok Yadav; Ait Bessai Sylia; Ashutosh Kumar Rai; Elhafid Nabti; Neelam Yadav; Ahmed M. Abdel-Azeem; Amrik Singh Ahluwalia
Endophytic fungi are largely recognized for their wide range of applications. They are known to be associated with a wide range of plants, both land- and water-based. Endophytic fungi residing inside plant tissues are very diverse and belong to phyla such as Ascomycota, Basidiomycota, and Mucoromycota. Endophytic fungi are a key source of natural compounds such as enzymes, secondary metabolites, and bioactive compounds, and these have several applications in human health as well as the agricultural and industrial sectors. Fungal endophytes are also utilized as bioinoculants to promote plant growth. Fungal endophytes show different plant growth-promoting abilities such as the solubilization of minerals as well as the production of phytohormones, siderophores, ammonia, and hydrogen cyanide that alleviate stress caused by nutrient depletion as well as environmental factors such as drought, salinity, flooding, and heavy metals. Endophytic fungi also play a pivotal role as biocontrol agents that help control pests and pathogens attacking various plants. In this chapter, their biodiversity, roles, and applications in various sectors are discussed in detail. © 2024 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies.
Hepatotoxic microcystins of cyanobacteria: Biosynthesis and degradation in response to abiotic stress
(CRC Press, 2013) Ashutosh Kumar Rai; Leanne Andrea Pearson; Ashok Kumar
Cyanobacteria (blue-green algae) are an ancient group of microorganisms that thrive in a broad spectrum of terrestrial, freshwater, and marine habitats ranging from hot springs to frozen ponds [1]. The successful colonization of this wide range of environments by cyanobacteria is linked to their long evolutionary history and adaptation to a number of environmental stresses such as high solar UV radiation, extreme temperatures, desiccation, oxidative stress, and nutrient fluctuations. Present-day cyanobacteria perform oxygenic photosynthesis and possess chlorophyll a and water-soluble phycobilin proteins [2,3]. Additionally, certain members of this order are capable of fixing atmospheric dinitrogen gas (N2), allowing them to colonize environments lacking a stable supply of fixed nitrogen [2]. A range of environmental conditions including higher temperatures and pH values, low turbulence, and high nutrient levels (eutrophication) can result in the proliferation of planktonic cyanobacteria in lakes and reservoirs, often leading to the formation of huge surface blooms. Certain bloom-forming cyanobacteria are also capable of producing secondary metabolites, which have a range of bioactivities, some of which are highly toxic to eukaryotic organisms including humans. Cyanotoxins are very diverse in terms of their chemical structure as well as their toxicity [4-7]. Based on the toxic effects they elicit, they may be classified as dermatotoxins (lipopolysaccharides, lyngbyatoxin-a, and aplysiatoxins), neurotoxins (anatoxin-a, homoanatoxin-a, anatoxin-a(s), and saxitoxins), and hepatotoxins (microcystins, nodularin, and cylindrospermopsin) [8-11]. Generally, these toxins are present within cells but can be released in high concentrations during cell lysis [10] or via active transport mechanisms [12]. © 2013 by Taylor & Francis Group, LLC.
Microbe-mediated remediation of dyes: Current status and future challenges
(Open Science Publishers LLP Inc., 2023) Kriti Akansha; Tanvir Kaur; Ashok Yadav; Divjot Kour; Ashutosh Kumar Rai; Sangram Singh; Shashank Mishra; Lalit Kumar; Kanika Miglani; Karan Singh; Ajar Nath Yadav
An array of industrial dyes most often azo dyes (–N=N–) deployed for different staining purposes, consequently impacting the environment significantly. The increasing pace of dye production often produces enormous wastewater from textile processing. After processing steps, dyes concentration remains left in expelled wastewater, consequently causing water pollution, and triggers negative toxicological impacts. However, remediation or decolorization is necessitating minimizing its negative consequences. Improper treatment of dye-containing waste waters triggers pollution of soil, water bodies, and so on. Numerous biological, physical, and chemical approaches for dye degradation and wastewater decolorization have been established. However, the high cost and practical feasibility of such methodologies remain obstacles in dye-containing wastewater. Microbial-assisted remediation is predominantly resilient to transforming dye compounds and reducing toxicity from water matrices in the ability to cope and provide cost-effective and efficient solutions. To cover the literature gap, and highlighting recent update information on dye remediation, we outlined different azo dyes, and their remediation deploying different physicochemical and microbial-mediated systems. In addition, recent advances in dye degradation, together with concluding remarks and future perspectives, have been pointed out. © 2023 Kriti Akansha, et al.
Microbes Mediated Nutrient Dynamics for Plant Growth Promotion: Current Research and Future Challenges
(Springer, 2024) Rubee Devi; Tanvir Kaur; Rajeshwari Negi; Babita Sharma; Sanjeev Kumar; Sangram Singh; Ashutosh Kumar Rai; Sarvesh Rustagi; Ashok Yadav; Anu Kumar; Divjot Kour; Ajar Nath Yadav
On earth, soil is one of the most essential parts of nature which plays critical roles in plant growth, water flow, waste products recycling and provides habitats to various organisms. Soil is the combination of organic matter, air, water minerals, and sixteen different essential nutrient elements which are categorized into primary macronutrients, secondary macronutrients, and micronutrients. The nutrients elements present in soil either in organic forms or organic forms interchanged by the various microbial mechanisms such including fixation, chelation and solubilization. The microbes from all three domain i.e., archaea, bacteria, and eukarya have been reported for exhibiting the various mechanisms and strain belonging to genera Arthrobacter, Burkholderia, Bacillus, Paenibacillus, Pseudomonas, Rhizobium, Natrinema, and Serratia are widely known for ruling the nutrients dynamics. The microbes playing role in nutrients dynamics, have great economic importance in agriculture sector as agriculturist is in pressure of producing high quality and quantity of food along with managing the sustainability. These microbes could solve agricultural problems such as soil degradation and environmental pollution by using them as bio-fertilizer over chemical-based products. A huge number of reports have supported such statements so, the purpose of the present review aims to complies microbial role in all category nutrients dynamics and their role in plant growth promotion. © Association of Microbiologists of India 2024.
Microbes Mediated Nutrient Dynamics for Plant Growth Promotion: Current Research and Future Challenges
(Springer, 2025) Rubee Devi; Tanvir Kaur; Rajeshwari Negi; Babita Sharma; Sanjeev Raj Kumar; Sangram N. Singh; Ashutosh Kumar Rai; Sarvesh Rustagi; Ashok Yadav; Anu Kumar; Divjot KOUR; Ajar Nath Yadav
On earth, soil is one of the most essential parts of nature which plays critical roles in plant growth, water flow, waste products recycling and provides habitats to various organisms. Soil is the combination of organic matter, air, water minerals, and sixteen different essential nutrient elements which are categorized into primary macronutrients, secondary macronutrients, and micronutrients. The nutrients elements present in soil either in organic forms or organic forms interchanged by the various microbial mechanisms such including fixation, chelation and solubilization. The microbes from all three domain i.e., archaea, bacteria, and eukarya have been reported for exhibiting the various mechanisms and strain belonging to genera Arthrobacter, Burkholderia, Bacillus, Paenibacillus, Pseudomonas, Rhizobium, Natrinema, and Serratia are widely known for ruling the nutrients dynamics. The microbes playing role in nutrients dynamics, have great economic importance in agriculture sector as agriculturist is in pressure of producing high quality and quantity of food along with managing the sustainability. These microbes could solve agricultural problems such as soil degradation and environmental pollution by using them as bio-fertilizer over chemical-based products. A huge number of reports have supported such statements so, the purpose of the present review aims to complies microbial role in all category nutrients dynamics and their role in plant growth promotion. © Association of Microbiologists of India 2024.
Microbes-mediated alleviation of heavy metal stress in crops: Current research and future challenges
(Open Science Publishers LLP Inc., 2022) Rubee Devi; Tanvir Kaur; Divjot Kour; Macie Hricovec; Rajinikanth Mohan; Neelam Yadav; Pankaj Kumar Rai; Ashutosh Kumar Rai; Ashok Yadav; Manish Kumar; Ajar Nath Yadav
Heavy metals (HMs) pollute the environment on a global scale and have different harmful effect on ecosystem. Outstripping accumulation of diverse toxic HMs in soils has altered the diversity, structure and function of microflora, degraded soils, reduces growth and yield of plant, and entered the food chain. HM treatment is necessary for maintaining the agricultural soil health. Many procedures and approaches have been used to recover contaminated soils in recent time, however, most of them were too pricey not environmentally friendly, and negatively affected soil properties. Usage of microbes was found as cost affective and ecofriendly approach for bioremediation of HMs. Microbes increased sustainability in agriculture soil health, which is essential to uninterrupted plant growth or improvement in stress full condition through mechanism likes productions phytohormones, organic acids, biosurfactants, exopolymers, antioxidant enzymes; and solubilization of phosphorus. It is well known that plant growth-promoting microbes enhance crop productivity and plant resistance to HM stress. In this following review, deep insight have has provided on mechanism of alleviation of HM stress by microbes and enhancement of plant growth promotion. © 2022 Devi, et al.
Physiological and molecular characterization of locally adapted Rhizobium strains of lentil (Lens culinaris Medik.) having restricted phage sensitivity
(2012) Sanjay Kumar Jaiswal; Banshi Dhar; Ashutosh Kumar Rai
Indigenous rhizobia were isolated from root nodules of lentil plants collected from various agro-climatic regions of India. These isolates together with four standard lentil Rhizobium strains were screened for sensitivity against eight phages. Four strains, USDA 2431, BHULR 104, BHULR 113 and BHULR 115 having restricted sensitivity to lytic phages LRP-1, LRP-4, LRP-13 and LRP-15 respectively, were characterized for both physiological and molecular characters. All strains had a generation time of between 3.8 and 5.6 h in yeast extract-mannitol (YM) broth, and colonies on YM agar plates showed an acidic reaction. Compared to other strains, strain USDA 2431 grew poorly when sucrose was the sole carbon source and showed maximum growth in arabinose-containing medium. The intrinsic antibiotic resistance level in all strains was tested against seven antibiotics and found to be high with ampicillin and kanamycin (50-60 μg ml-1) but very low with neomycin (0.03 μg ml-1).With the exception of strain BHULR 113, all strains expressed ex planta nitrogenase activity, with strain USDA 2431 showing the maximum activity (26.8 nmol C 2H4 h-1 mg-1 protein) after 6 h of incubation. Genomic and phylogenetic relationships among the strains were examined by randomly amplified polymorphic DNA and 16S rRNA sequence analysis. Genetic distance varied from 0.09 to 0.23 among the strains, and the primer OPL-11 was found to be suitable for the discrimination of these strains. The 16S rRNA sequence analysis revealed 99-100% similarity with Rhizobium leguminosarum bv. viciae. These results clearly indicate that phage sensitivity is a useful marker for discriminating locally soil-adapted rhizobial strains forming effective nodules in lentil. © 2012 Springer-Verlag and the University of Milan.
Potential effect of novel endophytic nitrogen fixing diverse species of Rahnella on growth promotion of wheat (Triticum aestivum L.)
(Springer, 2024) Kusam Lata Rana; Rajeshwari Negi; Babita Sharma; Ashok Yadav; Rubee Devi; Tanvir Kaur; Sheikh Shreaz; Sarvesh Rustagi; Ashutosh Kumar Rai; Sangram Singh; Divjot Kour; Ajar Nath Yadav
The present investigation aims to isolate nitrogen fixing endophytic bacteria from cereals crops and their potential role in plant growth promotion of wheat (Triticum aestivum L.) for sustainable growth. In the present investigation, endophytic bacteria were isolated from different cereal crops growing in the Divine Valley of Baru Sahib, Himachal Pradesh, India and isolates were screened for nitrogen fixation. The nitrogenase activity exhibiting bacterial isolates were further screened for other plant growth promoting traits including solubilization of phosphorus, potassium, and zinc; production of indole-3-acetic acid, siderophores, ammonia, hydrogen cyanide and extracellular enzyme. The potential nitrogen fixing strains were molecularly identified and evaluated for the growth promotion of wheat. A total of 304 putative endophytic bacterial isolates were isolated from wheat, oats, barley, and maize using selective and complex growth media. Among 304 putative endophytic bacteria, 8 isolates exhibits nitrogenase activity. On the basis of nitrogenase activity and other plant promoting traits, two efficient strains i.e. EU-E1ST3.1 and EU-A2RNfb were molecularly identified using 16S rRNA gene sequencing and found that these strains belongs to genera Rahnella. The wheat inoculated with two selected nitrogen-fixing endophytic bacterial strains showed considerable enhancement in total chlorophyll, nitrogen, Fe and Zn content over the un-inoculated control. In comparison of two selected nitrogen-fixing endophytic bacterial strains, Rahnella aquatilis EU-E1ST3.1 was found to enhance better growth and physiological parameters and it might be developed as biofertilizers to establish a sustainable agriculture system. In the present investigation, the isolated potential nitrogen fixing endophytic bacteria could be used as biofertilizer or bioinoculant for growth of diverse cereal crops growing in hilly region for agricultural sustainability. © The Author(s), under exclusive licence to Korean Society of Crop Science (KSCS) 2024.
Proteomic evidences for microcystin-RR-induced toxicological alterations in mice liver
(Nature Publishing Group, 2018) Ashutosh Kumar Rai; Rupesh Chaturvedi; Ashok Kumar
This study deals with the isolation and purification of an important variant of microcystins namely microcystin-RR (MCYST-RR) from Microcystis aeruginosa and reports its effects on mice liver protein profile and cellular functions. Protein profiling by 2-dimensional gel electrophoresis revealed changes in the number and accumulation of protein spots in liver of mice treated with different concentrations of MCYST-RR. Untreated (control) mice liver showed 368 protein spots while the number was 355, 348 and 332 in liver of mice treated with 200, 300 and 400 μg kg body wt-1 of MCYST-RR respectively. Altogether 102, 97, and 92 spots were differentially up-accumulated and 93, 91, and 87 spots were down- accumulated respectively with the treatment of 200, 300, 400 μg kg body wt-1. Eighteen differentially accumulated proteins present in all the four conditions were identified by MALDI-TOF MS. Of these eighteen proteins, 12 appeared to be involved in apoptosis/toxicological manifestations. Pathway analysis by Reactome and PANTHER database also mapped the identified proteins to programmed cell death/apoptosis clade. That MCYST-RR induces apoptosis in liver tissues was also confirmed by DNA fragmentation assay. Results of this study elucidate the proteomic basis for the hepatotoxicity of MCYST-RR which is otherwise poorly understood till date. © 2018 The Author(s).
RpoH2 sigma factor controls the photooxidative stress response in a non-photosynthetic rhizobacterium, Azospirillum brasilense Sp7
(2012) Santosh Kumar; Ashutosh Kumar Rai; Mukti Nath Mishra; Mansi Shukla; Pradhyumna Kumar Singh; Anil Kumar Tripathi
Bacteria belonging to the Alphaproteobacteria normally harbour multiple copies of the heat shock sigma factor (known as σ32, σH or RpoH). Azospirillum brasilense, a non-photosynthetic rhizobacterium, harbours five copies of rpoH genes, one of which is an rpoH2 homologue. The genes around the rpoH2 locus in A. brasilense show synteny with that found in rhizobia. The rpoH2 of A. brasilense was able to complement the temperature-sensitive phenotype of the Escherichia coli rpoH mutant. Inactivation of rpoH2 in A. brasilense results in increased sensitivity to methylene blue and to triphenyl tetrazolium chloride (TTC). Exposure of A. brasilense to TTC and the singlet oxygen-generating agent methylene blue induced several-fold higher expression of rpoH2. Comparison of the proteome of A. brasilense with its rpoH2 deletion mutant and with an A. brasilense strain overexpressing rpoH2 revealed chaperone GroEL, elongation factors (Ef-Tu and EF-G), peptidyl prolyl isomerase, and peptide methionine sulfoxide reductase as the major proteins whose expression was controlled by RpoH2. Here, we show that the RpoH2 sigma factor-controlled photooxidative stress response in A. brasilense is similar to that in the photosynthetic bacterium Rhodobacter sphaeroides, but that RpoH2 is not involved in the detoxification of methylglyoxal in A. brasilense. © 2012 SGM.
Structural and functional diversity of plant growth promoting microbiomes for agricultural sustainability
(Open Science Publishers LLP Inc., 2022) Tanvir Kaur; Divjot Kour; Olivia Pericak; Collin Olson; Rajinikanth Mohan; Ashok Yadav; Shashank Mishra; Manish Kumar; Ashutosh Kumar Rai; Ajar Nath Yadav
The plant allied microbes are phyllospheric, endophytic, and rhizospheric that is allied with plants eco-systems. These microbes have are termed as plant growth promoting (PGP) microbes as they have an ability to enhance growth of plant through indirectly or directly PGP mechanisms. The PGP microbes improve the growth and development of plant under both normal and diverse abiotic stresses conditions of temperatures, pH, salinity and drought. The microbes uses subsequent mechanism to stimulate the plant growth like biological nitrogen fixation; solubilization of minerals (P, K and Zn); production of phyto-hormones (Indole acetic acid, cytokinin and gibberellic acid); 1-aminocyclopropane-1-carboxylate deaminase attributes; production of extracellular hydrolytic enzymes (amylase, cellulase, chitanase, pectinase, protease, and xylanase), siderophores, hydrogen cyanide and ammonia. The PGP microbes sorted out from soil and plant associated are belong to several phylum of all three domain, that is, Archaea, Bacteria and Eukarya with predominant species of genera Arthrobacter, Pseudomonas, Aspergillus, Bacillus, Burkholderia, Colletotrichum, Exiguobacterium, Flavobacterium, Fusarium, Halobacillus, Haloferax, Lysinibacillus, Paenibacillus, Penicillium, Psychrobacter, Sediminibacillus, Streptomyces, Trichoderma, and Virgibacillus. In agriculture PGP microbiomes potentiality has increased steadily as it is an effective way to reduce the use of different chemical-based fertilizer, pesticide and other supplements. Present progress on research related to PGP microbial diversity (plant and soil microbiomes), along with their colonizing capability and action’s mechanism should increase their applications for plant growth and disease management of agricultural system toward the agricultural sustainability. Present review deals with the structural and functional diversity of PGP microbiomes for agricultural sustainability. © 2022 Kaur, et al.