Browsing by Author "Suresh Kumar Dubey"

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Antimicrobial resistance in plant endophytes associated with poultry-manure application revealed by selective culture and whole genome sequencing
(Elsevier B.V., 2024) Animesh Tripathi; Anjali Jaiswal; Dinesh Kumar; Priyank Chavda; Ramesh Pandit; Madhvi Joshi; Damer P. Blake; Fiona M. Tomley; Chaitanya G. Joshi; Suresh Kumar Dubey
Poultry manure is widely used as organic fertilizer in agriculture during the cultivation of crops, but the persistent high-level use of antibiotics in poultry production has raised concerns about the selection for reservoirs of antimicrobial resistance genes (ARGs). Previous studies have shown that the addition of poultry manure can increase the abundance of genes associated with resistance to tetracyclines, aminoglycosides, fluoroquinolones, sulfonamides, bacitracin, chloramphenicol, and macrolide-lincosamide-streptogramin in soil and plants. Understanding the microbial populations that harbor these ARGs is important to identify microorganisms that could enter the human food chain. Here, we test the hypothesis that environmental exposure to poultry manure increases the occurrence of antimicrobial resistance (AMR) in plant endophytes using selective culture, phenotypic Antibiotic Susceptibility Testing (AST), phylogenetic analysis, and whole genome sequencing (WGS). Endophytes from poultry manure treated Sorghum bicolor (L.) Moench plant root and stem samples showed increased phenotypic and genotypic resistance against multiple antibiotics compared to untreated controls. Comparison of AMR phenotype-to-genotype relationships highlighted the detection of multi-drug resistant (MDR) plant endophytes, demonstrating the value of genomic surveillance for emerging drug-resistant pathogens. The increased occurrence of ARGs in poultry manure-exposed endophytes highlights the need for responsible antibiotic use in poultry and animal farming to reduce contamination of ecological niches and transgression into endophytic plant microbiome compartments. It also emphasizes the requirement for proper manure management practices and vigilance in monitoring and surveillance efforts to tackle the growing problem of antibiotic resistance and preserve the efficacy of antibiotics for human and veterinary medicine. © 2024 Elsevier B.V.
Antimicrobial Resistance Transmission in Environmental Matrices: Current Prospects and Future Directions
(Springer, 2025) Mrinmoy Patra; Suresh Kumar Dubey
The advent of antibiotics, once hailed as a revolutionary medical solution, has now brought forth a troubling consequence: the rise of antimicrobial resistance (AMR). This phenomenon, spurred by the widespread use and misuse of antibiotics in human healthcare, agriculture, aquaculture and livestock sectors, has emerged as a significant public health threat with profound environmental implications. Antibiotic residues, antibiotic resistant bacteria (ARB), and antibiotic resistance genes (ARGs) now pervade multiple environmental matrices, including wastewater, soil, surface and groundwater, air, landfill leachates, and aquatic systems, enabling horizontal gene transfer (HGT) and the evolution of multidrug resistant (MDR) organisms. Among these, wastewater treatment plants act as central repositories for largely unmetabolized or partially metabolized antibiotics, ARBs, and ARGs, yet similar concerns arise from agricultural runoff, reclaimed wastewater irrigation, aquaculture discharge, and atmospheric microparticles. This review adopts the One Health approach to explore the integrated pathways through which AMR disseminates across ecological boundaries and ultimately affects human and animal health. We emphasize the roles of environmental compartments in shaping resistome dynamics and highlight mitigation strategies ranging from advanced treatment technologies to sustainable agricultural practices essential for curbing the environmental implications of AMR. Therefore, through comprehensive analysis and integration, this study contributes to the current knowledge and persistent challenges, thus providing actionable insights to guide interdisciplinary efforts in managing the environmental dimension of AMR. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.
Assessment of environmental gene tags linked with carbohydrate metabolism and chemolithotrophy associated microbial community in River Ganga
(Elsevier B.V., 2019) Bhaskar Reddy; Jitendra Pandey; Suresh Kumar Dubey
The microbial community mediated biogeochemical cycles play important role in global C-cycle and display a sensitive response to environmental changes. Limited information is available on microbial composition and functional diversity controlling biogeochemical cycles in the riverine environment. The Ganga River water and sediment samples were studied for environmental gene tags with reference to carbohydrate metabolism, photoheterotrophy and chemolithotrophy using high throughput shotgun metagenomic sequencing and functional annotation. The diversity of environmental gene tags specific microbial community was annotated against reference sequence database using Kaiju taxonomic classifier. The metagenomic analyses revealed that the river harbored a broad range of carbohydrate and energy metabolism genes. The in-depth investigation of metagenomic data revealed that the enzymes associated with reverse TCA cycle, Calvin-Benson cycle enzyme RuBisCO, starch and sucrose metabolism genes were highly abundant. The enzymes associated with sulfur metabolism such as EC:2.7.7.4 (sulfate to ammonium per sulfate), EC:1.8.1.2, EC:1.8.7.1 (sulfite to H 2 S) were prevalent in both the class of samples. The principal component analysis of the functional profiles revealed that the water and sediment samples were clustered distinctly suggesting that both the sites had variable abundance of functional genes and associated microbiota. The taxonomic classification showed abundance of Proteobacteria, Actinobacteria and Bacteroidetes phyla. Also, the metagenomic study showed the presence of purple sulfur bacteria viz. Thiodictyon, Nitrosococcus and purple non-sulfur bacteria viz. Bradyrhozobium and Rhodobacter. The study demonstrates that the Ganga River microbiome has prevalence of functional genes involved in carbohydrate anabolism and catabolism, and CO 2 fixation with great prospects in cellulose and sulfide degrading enzyme production and characterization. © 2019
ATP-binding cassette (ABC) import systems of Mycobacterium tuberculosis: target for drug and vaccine development
(Taylor and Francis Ltd., 2020) Dharmendra Kumar Soni; Suresh Kumar Dubey; Rakesh Bhatnagar
Nutrient procurement specifically from nutrient-limiting environment is essential for pathogenic bacteria to survive and/or persist within the host. Long-term survival or persistent infection is one of the main reasons for the overuse of antibiotics, and contributes to the development and spread of antibiotic resistance. Mycobacterium tuberculosis is known for long-term survival within the host, and develops multidrug resistance. Before and during infection, the pathogen encounters various harsh environmental conditions. To cope up with such nutrient-limiting conditions, it is crucial to uptake essential nutrients such as ions, sugars, amino acids, peptides, and metals, necessary for numerous vital biological activities. Among the various types of transporters, ATP-binding cassette (ABC) importers are essentially unique to bacteria, accessible as drug targets without penetrating the cytoplasmic membrane, and offer an ATP-dependent gateway into the cell by mimicking substrates of the importer and designing inhibitors against substrate-binding proteins, ABC importers endeavour for the development of successful drug candidates and antibiotics. Alternatively, the production of antibodies against substrate-binding proteins could lead to vaccine development. In this review, we will emphasize the role of M. tuberculosis ABC importers for survival and virulence within the host. Furthermore, we will elucidate their unique characteristics to discover emerging therapies to combat tuberculosis. © 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group, on behalf of Shanghai Shangyixun Cultural Communication Co., Ltd.
Bacterial Community Structure in the Rhizosphere of a Cry1Ac Bt-Brinjal Crop and Comparison to Its Non-transgenic Counterpart in the Tropical Soil
(2013) Amit Kishore Singh; Govind Kumar Rai; Major Singh; Suresh Kumar Dubey
To elucidate whether the transgenic crop alters the rhizospheric bacterial community structure, a 2-year study was performed with Cry1Ac gene-inserted brinjal crop (Bt) and their near isogenic non-transformed trait (non-Bt). The event of Bt crop (VRBT-8) was screened using an insect bioassay and enzyme-linked immunosorbent assay. Soil moisture, NH4 +-N, NO3 --N, and PO4 --P level had non-significant variation. Quantitative polymerase chain reaction revealed that abundance of bacterial 16S rRNA gene copies were lower in soils associated with Bt brinjal. Microbial biomass carbon (MBC) showed slight reduction in Bt brinjal soils. Higher MBC values in the non-Bt crop soil may be attributed to increased root activity and availability of readily metabolizable carbon compounds. The restriction fragment length polymorphism of PCR-amplified rRNA gene fragments detected 13 different bacterial groups with the exclusive presence of β-Proteobacteria, Chloroflexus, Planctomycetes, and Fusobacteria in non-Bt, and Cyanobacteria and Bacteroidetes in Bt soils, respectively, reflecting minor changes in the community structure. Despite the detection of Cry1Ac protein in the rhizospheric soil, the overall impact of Cry1Ac expressing Bt brinjal was less compared to that due to seasonal changes. © 2013 Springer Science+Business Media New York.
Biodegradation of acetaminophen: Current knowledge and future directions with mechanistic insights from omics
(Elsevier Ltd, 2025) Bhavana Pandey; Anand Kumar Pandey; Laliteshwari Bhardwaj; Suresh Kumar Dubey
Acetaminophen (APAP), one of the most frequently used antipyretic and analgesic medications, has recently grown into a persistent organic contaminant of emerging concern due to its over-the-counter and widespread use. The excessive accumulation of APAP and its derivatives in various environmental matrices is threatening human health and the ecosystem. The complexity of APAP and its intermediates augments the need for adequate innovative and sustainable strategies for the remediation of contaminated environments. Bioremediation serves as an efficient, eco-friendly, cost-effective, and sustainable approach to mitigate the toxic impacts of APAP. The present review provides comprehensive insights into the ecotoxicity of APAP, its complex biodegradation pathways, and the various factors influencing biodegradation. The omics approaches viz., genomics/metagenomics, transcriptomics/metatranscriptomics, proteomics, and metabolomics have emerged as powerful tools for understanding the diverse APAP-degraders, degradation-associated genes, enzymatic pathways, and metabolites. The outcomes revealed amidases, deaminases, oxygenases, and dioxygenases as the lead enzymes mediating degradation via 4-aminophenol, hydroquinone, hydroxyquinol, 3-hydroxy-cis, cis-muconate, etc. as the major intermediates. Overall, a holistic approach with the amalgamation of omics aspects would accelerate the bioaugmentation processes and play a significant role in formulating strategies for remediating and reducing the heavy loads of acetaminophen from the environmental matrices. © 2025 Elsevier Ltd
Biodegradation of acetaminophen: Microcosm centric genomic-proteomic-metabolomics evidences
(Elsevier Ltd, 2024) Bhavana Pandey; Anand Kumar Pandey; Kritika Tripathi; Suresh Kumar Dubey
Acetaminophen (APAP) is a frequently used, over-the-counter analgesic and antipyretic medication. Considering increase in global consumption, its ubiquity in environment with potential toxic impacts has become a cause of great concern. Hence, bioremediation of this emerging contaminant is of paramount significance. The present study incorporates a microcosm centric omics approach to gain in-depth insights into APAP degradation by Paracoccus sp. APAP_BH8. It can metabolize APAP (300 mg kg−1) within 16 days in soil microcosms. Genome analysis revealed potential genes capable of mediating degradation includes M20 aminoacylase family protein, guanidine deaminase, 4-hydroxybenzoate 3-monooxygenase, and 4-hydroxyphenylpyruvate dioxygenase. Whole proteome analysis showed differential expression of enzymes and bioinformatics provided evidence for stable binding of intermediates at the active site of considered enzymes. Metabolites identified were 4-aminophenol, hydroquinone, and 3-hydroxy-cis, cis-muconate. Therefore, Paracoccus sp. APAP_BH8 with versatile enzymatic and genetic attributes can be a promising candidate for formulating improved in situ APAP bioremediation strategies. © 2024 Elsevier Ltd
Biodegradation of chlorpyrifos by Pseudomonas sp. in a continuous packed bed bioreactor
(Elsevier Ltd, 2014) Maya Yadav; Navnita Srivastva; Ram Sharan Singh; Siddh Nath Upadhyay; Suresh Kumar Dubey
Biodegradation of chlorpyrifos (CP) by Pseudomonas (Iso 1) sp. was investigated in batch as well as continuous bioreactors packed with polyurethane foam pieces. The optimum process parameters for the maximum removal of CP, determined through batch experiments, were found to be: inoculum level, 300×106CfumL-1; CP concentration, 500mgL-1; pH 7.5; temperature, 37°C and DO, 5.5mgL-1. The continuous packed bed bioreactor was operated at various flow rates (10-40mLh-1) under the optimum conditions. The steady state CP removal efficiency of more than 91% was observed up to the inlet load of 300mgL-1d-1. The bioreactor was sensitive to flow fluctuations but was able to recover its performance quickly and exhibited the normal plug-flow behavior. Accumulation of TCP (3,5,6-trichloro-2-pyridinol) affected the reactor performance. © 2014 Elsevier Ltd.
Biodegradation of fipronil: molecular characterization, degradation kinetics, and metabolites
(Springer Science and Business Media Deutschland GmbH, 2023) Anjali Jaiswal; Animesh Tripathi; Suresh Kumar Dubey
Fipronil (C12H4Cl2F6N4OS) is a commonly used insecticide effective against numerous insects and pests. Its immense application poses harmful effects on various non-target organisms as well. Therefore, searching the effective methods for the degradation of fipronil is imperative and logical. In this study, fipronil-degrading bacterial species are isolated and characterized from diverse environments using a culture-dependent method followed by 16S rRNA gene sequencing. Phylogenetic analysis showed the homology of organisms with Acinetobacter sp., Streptomyces sp., Pseudomonas sp., Agrobacterium sp., Rhodococcus sp., Kocuria sp., Priestia sp., Bacillus sp., Aeromonas sp., and Pantoea sp. The bacterial degradation potential for fipronil was analyzed through high-performance liquid chromatography (HPLC). Incubation-based degradation studies revealed that Pseudomonas sp. and Rhodococcus sp. were found to be the most potent isolates that degraded fipronil at 100 mg L−1 concentration, with removal efficiencies of 85.9 and 83.6%, respectively. Kinetic parameter studies, following the Michaelis-Menten model, also revealed the high degradation efficiency of these isolates. Gas chromatography-mass spectrometry (GC-MS) analysis revealed fipronil sulfide, benzaldehyde, (phenyl methylene) hydrazone, isomenthone, etc., as major metabolites of fipronil degradation. Overall investigation suggests that native bacterial species isolated from the contaminated environments could be efficiently utilized for the biodegradation of fipronil. The outcome derived from this study has immense significance in formulating an approach for bioremediation of fipronil-contaminated surroundings. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Biodegradation of imidacloprid: Molecular and kinetic analysis
(Elsevier Ltd, 2022) Pallavi Gautam; Suresh Kumar Dubey
Imidacloprid (C9H10ClN5O2) is the most widely used insecticide. Its persistence and toxic nature have caused a detrimental effect on living biota. Thus its removal from the contaminated environment has become imperative. The present study aimed to isolate bacterial species from pesticide-contaminated sites and assess their potential for biodegradation of imidacloprid. The 16S rRNA analysis revealed the genetic relatedness of isolates to Sphingobacterium sp., Agrobacterium sp., Pseudomonas sp., and Bacillus sp. Batch biodegradation studies showed that Sphingobacterium sp. and Agrobacterium sp. were the most promising isolates as they degraded 81.0% and 84.9%, respectively, of imidacloprid at the concentration of 95 mg/L via co-metabolism. Kinetic study (Vmax/Ks ratio) also suggested the high degradation efficiency of these isolates. Imidacloprid-guanidine (C9H11ClN4) was identified as the metabolite. This report highlights the potential of bacteria for imidacloprid degradation and could be utilized for the formulation of strategies for the remediation of imidacloprid contaminated environments. © 2022
Biodegradation of isoprene by Arthrobacter sp. strain BHU FT2: Genomics-proteomics enabled novel insights
(Elsevier Ltd, 2021) Abhishek Singh; Anand Kumar Pandey; Suresh Kumar Dubey
The bacterial degradation of isoprene is important for maintaining its atmospheric concentration in unpolluted environment. It may be possible to use natural isoprene degrading bacteria in engineered systems to eliminate or limit isoprene emissions from various sources. Biodegradation of isoprene by Arthrobacter sp. strain BHU FT2 was investigated. The genome was found to contain 4151545 bp long chromosome having 3747 coding genes, and coded potential isoprene degrading enzymes. The molecular docking of monooxygenases with isoprene displayed a higher binding energy (−4.59 kcal/mol) for WP_015938387.1 monooxygenase. Analysis of the identified monooxygenases with the known isoprene monooxygenases revealed 67% sequence identity of WP_015938387.1 (Locus tag JHV56_10705) monooxygenase of the considered strain with the OPX16961.1 monooxygenase of Gordonia sp. i37 isoprene degrading starin. These results provided a strong evidence for the high isoprene degrading potential of the Arthrobacter sp. BHU FT2 which could be efficiently exploited for isoprene degradation in large scale bio-filtration units. © 2021 Elsevier Ltd
Biodegradation of Neonicotinoids: Current Trends and Future Prospects
(Springer Science and Business Media Deutschland GmbH, 2023) Pallavi Gautam; Suresh Kumar Dubey
Purpose of Review: Neonicotinoids are synthetic insecticides, and among all agrochemicals, they rank second in consumption. The unparalleled use of neonicotinoids in various sectors including agriculture has currently reintroduced them as emerging pollutants/hazards due to their endocrine-disrupting nature. High water solubility, low volatility, and persistent nature have resulted in their accumulation in the environment. Thus, investigating efficient and sustainable methods for the remediation of contaminated environments due to this pollutant is imperative. Recent Findings.: Bioremediation provides a cost-effective and environment-friendly option over conventional physicochemical techniques that produce toxic byproducts. The microbial route for degradation has the potential to completely mineralize neonicotinoids by virtue of their adaptive and diverse metabolic machinery. Potent microbes such as Ensifer, Phanerochaete, Bacillus, Ochrobactrum, Trametes, Rhodococcus, Sphingobacterium, and Pseudomonas have been isolated and screened for their immense degradation potential, and the metabolites, degradative enzymes, and transformation pathways have been elucidated. The incorporation of modern tools/techniques such as metabolic engineering, microbial biotechnology, omics-based database approaches or systems biology, artificial intelligence, and machine learning can fasten and give better bioremediation results. Summary: This study has aimed to summarize the processes employed to date to degrade neonicotinoids and present a comprehensive report reflecting past efforts, advances, and future prospects. Therefore, this report will be beneficial in strengthening the understanding of the extent of efforts made for neonicotinoid degradation and how conventional approaches such as bioaugmentation, biostimulation, and biofiltration can be accelerated by advanced technologies viz., omics and machine learning. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
Biosensor for the detection of Listeria monocytogenes: emerging trends
(Taylor and Francis Ltd, 2018) Dharmendra Kumar Soni; Rafiq Ahmad; Suresh Kumar Dubey
The early detection of Listeria monocytogenes (L. monocytogenes) and understanding the disease burden is of paramount interest. The failure to detect pathogenic bacteria in the food industry may have terrible consequences, and poses deleterious effects on human health. Therefore, integration of methods to detect and trace the route of pathogens along the entire food supply network might facilitate elucidation of the main contamination sources. Recent research interest has been oriented towards the development of rapid and affordable pathogen detection tools/techniques. An innovative and new approach like biosensors has been quite promising in revealing the foodborne pathogens. In spite of the existing knowledge, advanced research is still needed to substantiate the expeditious nature and sensitivity of biosensors for rapid and in situ analysis of foodborne pathogens. This review summarizes recent developments in optical, piezoelectric, cell-based, and electrochemical biosensors for Listeria sp. detection in clinical diagnostics, food analysis, and environmental monitoring, and also lists their drawbacks and advantages. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.
Biotechnological potential for degradation of isoprene: a review
(Taylor and Francis Ltd, 2018) Navnita Srivastva; Abhishek Singh; Yashpal Bhardwaj; Suresh Kumar Dubey
Isoprene, the ubiquitous, highly emitted non-methane volatile hydrocarbon, affects atmospheric chemistry and human health, and this makes its removal from the contaminated environment imperative. Physicochemical degradation of isoprene is inefficient and generates secondary pollutants. Therefore, biodegradation can be considered as the safer approach for its efficient abatement. This review summarizes efforts in this regard that led to tracking the diverse groups of isoprene degrading bacteria such as Methanotrophs, Xanthobacter, Nocardia, Alcaligenes, Rhodococcus, Actinobacteria, Alphaproteobacteria, Bacteriodetes, Pseudomonas, and Alcanivorax. Biodegradation of isoprene by such bacteria in batch and continuous modes has been elaborated. The products, pathways and the key enzymes associated with isoprene biodegradation have also been presented. © 2017 Informa UK Limited, trading as Taylor & Francis Group.
Cellulose degradation potential of Paenibacillus lautus strain BHU3 and its whole genome sequence
(Elsevier Ltd, 2018) Suman Yadav; Suresh Kumar Dubey
The aim of this work was to study cellulose degradation and whole genome sequence of Paenibacillus lautus BHU3 isolate. The 16S rRNA gene sequence analysis revealed genetic relatedness (99%) of Iso 7 with Paenibacillus lautus, Iso 8 with Paenibacillus lactis, and Iso 9 with Bacillus amyloliquefaciens. Clear zone formation followed by CMCase and FPase assays exhibited cellulolytic potential in the order: P. lautus > P. lactis > B. amyloliquefaciens. The most potent isolate, Paenibacillus lautus strain BHU3 was subjected to whole genome analysis with reference to the genomic basis of cellulose degradation. Results showed that P. lautus strain BHU3 contains 6234 protein coding genes of which, 316 were associated with the carbohydrate metabolism. Further, genomic CAZymes analysis indicated that the P. lautus strain BHU3 comprising a range of glycoside hydrolase (GH) family genes (143), may play the vital role(s) in enhancing the cellulolytic attributes, and could be the useful tool for lignocellulosic biomass degradation and waste management. © 2018 Elsevier Ltd
Challenges and knowledge gaps in ecological sciences
(Indian Academy of Sciences, 2018) Suresh Kumar Dubey; Jitendra Pandey
[No abstract available]
Changes in Actinomycetes community structure under the influence of Bt transgenic brinjal crop in a tropical agroecosystem
(2013) Amit Kishore Singh; Major Singh; Suresh Kumar Dubey
Background: The global area under brinjal cultivation is expected to be 1.85 million hectare with total fruit production about 32 million metric tons (MTs). Brinjal cultivars are susceptible to a variety of stresses that significantly limit productivity. The most important biotic stress is caused by the Brinjal fruit and shoot Borer (FSB) forcing farmers to deploy high doses of insecticides; a matter of serious health concern. Therefore, to control the adverse effect of insecticides on the environment including the soil, transgenic technology has emerged as the effective alternative. However, the reports, regarding the nature of interaction of transgenic crops with the native microbial community are inconsistent. The effect of a Bt transgenic brinjal expressing the bio-insecticidal protein (Cry1Ac) on the rhizospheric community of actinomycetes has been assessed and compared with its non-transgenic counterpart. Results: Significant variation in the organic carbon observed between the crops (non-Bt and Bt brinjal) may be due to changes in root exudates quality and composition mediated by genetic attributes of Bt transgenic brinjal. Real time quantitative PCR indicated significant differences in the actinomycetes- specific 16S rRNA gene copy numbers between the non-Bt (5.62-27.86) × 1011 g-1 dws and Bt brinjal planted soil (5.62-24.04) × 1011 g-1 dws. Phylogenetic analysis indicated 14 and 11, actinomycetes related groups in soil with non-Bt and Bt brinjal crop, respectively. Micrococaceaea and Nocardiodaceae were the dominant groups in pre-vegetation, branching, flowering, maturation and post-harvest stage. However, Promicromonosporaceae, Streptosporangiaceae, Mycobacteriaceae, Geodermatophilaceae, Frankiaceae, Kineosporaceae, Actisymmetaceae and Streptomycetaceae were exclusively detected in a few stages in non-Bt brinjal rhizosphere soil while Nakamurellaceae, Corynebactericeae, Thermomonosporaceae and Pseudonocardiaceae in Bt brinjal counterpart. Conclusion: Field trails envisage that cultivation of Bt transgenic brinjal had negative effect on organic carbon which might be attributed to genetic modifications in the plant. Changes in the organic carbon also affect the actinomycetes population size and diversity associated with rhizospheric soils of both the crops. Further long-term study is required by taking account the natural cultivar apart from the Bt brinjal and its near-isogenic non-Bt brinjal with particular reference to the effects induced by the Bt transgenic brinjal across different plant growth stages. © 2013 Singh et al.; licensee BioMed Central Ltd.
Changes in pmoA gene containing methanotrophic population and methane oxidation potential of dry deciduous tropical forest soils
(Indian Academy of Sciences, 2020) Yashpal Bhardwaj; Suresh Kumar Dubey
In natural ecosystems such as forests topographical gradients, species composition variability and seasonality, are the potential drivers of methane (CH4) metabolism, and thus, of the population size and activities of methane oxidizing bacteria (MOB). To test the hypothesis that topography, tree species and seasonal variability influence MOB population and soil methane oxidation potential (MOP), we conducted two consecutive years of study selecting three sites in a dry deciduous tropical forest in Chandauli district of eastern Uttar Pradesh, India. The qPCR results showed a large variation in MOB population size (copies g-1 dws), ranging from 1.0 x 106 to 2.1 x 107 and 9.0 x 105 to 2.2 x 107 during 2016 and 2017 respectively. The distribution of MOB population revealed the trend: hilltop > middle > hillbase with its maxima in the winter and minima in the rainy season. Laboratory incubation study revealed a similar trend in soil MOP (ng CH4 g-1 h-1 dws), it varied from 10.6 to 20.6 and 10.5 to 20.7 during 2016 and 2017 respectively. The outer canopy soils showed lower MOB population and MOP compared to under canopy soils of tree species Butea monosperma, Madhuca indica and Tectona grandis during both years of study. The topography, season and tree species significantly influenced the MOB population size and MOP. Soil MOP showed a highly significant correlation (r = 0.89; p < 0.01) with MOB population, and a negative correlation was found with soil moisture (r = 0.76; p < 0.01). The results indicate that the dry deciduous tropical forest soils are potential sinks of atmospheric CH4 wherein, the MOB population characteristically responds to topographical changes, tree species and seasonal shifts driving collectively the overall MOP of forest soils. © 2020, Indian Academy of Sciences.
Characterization of bacterial isolates from rubber dump site and their use in biodegradation of isoprene in batch and continuous bioreactors
(Elsevier Ltd, 2015) Navnita Srivastva; Awadhesh Kumar Shukla; Ram Sharan Singh; Siddh Nath Upadhyay; Suresh Kumar Dubey
Bacterial isolates from contaminated soil of a waste rubber dumping site were isolated and characterized using biochemical and molecular approaches. Isoprene degradation kinetics in batch mode (isoprene concentration: 100-1000ppm) revealed the degradation efficiency of isolates as: Pseudomonas sp. (83%)>Alcaligenes sp. (70%)>Klebsiella sp. (68.5%). The most efficient isolate Pseudomonas sp. was finally inoculated in a specifically designed bioreactor system comprising a bioscrubber and a biofilter packed with polyurethane foam connected in series. The bioscrubber and biofilter units when operated in a series showed more than 90% removal efficiency up to the inlet loading rate (IL) of 371.1g/m3/h. Maximum elimination capacity (EC) of biofilter was found to be an order of magnitude greater than that for bioscrubber. Oxidative cleavage of the double bond of isoprene has been revealed through IR spectra of the leachate. © 2015 Elsevier Ltd.
Current Developments in Biotechnology and Bioengineering: Crop Modification, Nutrition, and Food Production
(Elsevier Inc., 2016) Suresh Kumar Dubey; Ashok Pandey; Rajender Singh Sangwan
Current Developments in Biotechnology and Bioengineering: Crop Modification, Nutrition, and Food Production provides extensive coverage of new developments, state-of-the-art technologies, and potential future trends, presenting data-based scientific knowledge on agribiotechnology and describing world agriculture and the role biotechnology can play in ensuring food security over the next fifty years. The book discusses the effects of climate change in agriculture and the resultant emergence of new crops, including drought tolerant and more nutritious plants. In addition, the book discusses insect and virus resistance in plants and outlines plant metabolic engineering for agriculture, genetically engineered plants, and microbial diseases. Highlights recent developments in agriculture due to biotechnology. Relates the effect of climate change in agriculture to the development of new crops. Describes the application of metabolic engineering in the development of new genetically modified plants. © 2017 Elsevier B.V. All rights reserved.