Life on Planet: Its Origin and Expansion Across Earth’s Ecosystem Ranbir Chander Sobti, Indu Sharma, R. K. Negi, Sonakshi Modeel Biotechnology Innovations for A Sustainable Future Integrating Clean Energy Life on the Planet Clean Water and Climate Action, 2026
A novel non-invasive imaging technique for mapping microplastic accumulation and distribution in different organ systems of Indian major carp Labeo rohita (Ham. 1822) Sneha Siwach, Aviral Singh, Soumyadeep Paul, Vanika Gupta, Ishaan Gupta, Ram Krishan Negi Current Research in Toxicology, 2026 . Fluorescence microscopy confirmed presence of MPs in the gastrointestinal (GI) tract, gills, muscle tissues and excreta of exposed fish, whereas, micro-computed tomography (µ-CT) facilitated non-destructive, three-dimensional whole-body imaging, allowing precise localization and visualization of internalized particles within intact organisms. A clear, progressive and exposure-dependent increase in microplastic presence was observed over the 28-day experimental period, supported by non-parametric trend and effect-size analyses, with consistently higher relative burdens under waterborne exposure compared to the dietary exposure, as revealed by complementary µ-CT and fluorescence imaging. Detection of microplastics in muscle tissue indicates systemic translocation beyond primary uptake organs, whereas their presence in excreta confirms active elimination processes. Strong spatial concordance between µ-CT and fluorescence microscopy validates the robustness of the dual-imaging approach. Collectively, this study advances microplastic ecotoxicology by establishing a scalable, high-resolution, non-invasive imaging framework for mapping and tracking microplastic fate in freshwater systems as well as organ-specific microplastic distribution and burden in freshwater fish under environmentally realistic exposure conditions.
Emerging risk factors and the role of gut microbiota in immunomodulation and therapeutic implications in colorectal cancer Sonakshi Modeel, Sneha Siwach, Padma Dolkar, Meenu Chaurasia, Pankaj Yadav, Apoorva Atri, Aarzoo Yadav, Tarana Negi, Ram Krishan Negi Cancer Pathogenesis and Therapy, 2026 The pathophysiology of many ailments, including neurological, gastrointestinal, and metabolic problems, is well known to be influenced by intestinal dysbiosis. Clinical research has provided evidence suggesting a strong correlation between dysbiosis of the gut microbiome and colorectal cancer (CRC) development. The active reprogramming of metabolic pathways to boost glycolysis, fatty acid production, lipogenesis, and glutaminolysis constitutes a major metabolic shift in cancer development, including CRC. The complex combination of different factors leads to CRC, making it an environmental disease. These factors include food and lifestyle choices, genetics and family history, age, underlying intestinal diseases, and dysbiosis of the gut microbiota. One of the primary risk factors for carcinoma development is diet, which impacts an individual's gut microbiome. In addition to impacting CRC formation, the gut microbiome also has immunomodulatory effects, including various immunological interactions and the underlying mechanisms governing them. Microbial interactions in CRC have been extensively studied, yet numerous unresolved queries exist on how gut bacteria can influence treatment. It is possible to perform microbiome-driven immunotherapies focusing on probiotics, prebiotics, and synbiotics. However, large-scale treatment utilization in CRC patients is limited by several issues, including variations in the microbial makeup of each patient's gut and a lack of established methods. The study highlights the impact of several risk factors, including dysbiosis of the gut microbiome and different approaches to halting and treating CRC progression with a focus on diet changes and modulation of the gut flora. Given the foregoing, we propose that if research gaps are addressed and immunotherapy is paired with microbial interventions, microbiota-based therapeutics could potentially impede the growth of tumors and treat CRC.
Sustainable aquaculture: A blueprint for achieving zero hunger Sneha Siwach, Apoorva, Meenu Chaurasia, Padma Dolkar, Aarzoo Yadav, Pankaj Yadav, L. Themchuirin, Nongmaithem Sonia, Drishti Kohli, Priyanka Paswan, Ram Krishan Negi Biotechnology Innovations and Sustainability for Zero Hunger, 2025 Many of the developing countries on the coast rely on the revenues and trade that come from fish and fishery products. Aquaculture is not a new production method, although in the last few decades the volume and quality of the final product have changed significantly. It is one of the most rapidly growing businesses with 1% annual growth rate. Since the late 1990s, the international aquaculture industry has expanded and has effectively contributed to achieving the sustainability goals of the economy, environment, and social aspects. It is crucial to reconsider the further development of aquaculture and its contribution to the second SDG of the UN, which is the elimination of hunger on the planet, as well as the growing gap between the rich and the poor. Being one of the fastest growing sectors within the food systems, aquaculture increases the production of valuable nutrients such as high-quality proteins, omega 3 fatty acids, and micronutrients such as iodine, vitamin D, and B12. Such nutrients are vital for fighting malnutrition, especially among the poor patterns and areas of food deficit. The world is becoming more in need of seafood with aquaculture being seen as a practical solution to high demands quite different from farming. The current global discrepancy in the degree of sustainable aquaculture growth, both across and within nations, is particularly noticeable when it comes to human access to aquatic food produced through farming. The chapter calls for sustainability and technology that can help increase production and provide more reliable sources of food, highlighting the centrality of aquaculture in the fight against global hunger and malnutrition worldwide. It also emphasizes the importance of aquaculture when it comes to fighting hunger at the global level and accomplishing the main sustainable development goal of the United Nations (SDG 2), which is zero hunger.
A comprehensive DNA barcoding of Indian freshwater fishes of the Indus River system, Beas Sonakshi Modeel, Ram Krishan Negi, Monika Sharma, Padma Dolkar, Sheetal Yadav, Sneha Siwach, Pankaj Yadav, Tarana Negi Scientific Reports, 2024 The Beas River is one of the important rivers of the Indus River system located in Himachal Pradesh, India, that harbors a diverse range of freshwater fish species. The present study employed COI gene to investigate the ichthyofaunal diversity of river Beas. Through the sequencing of 203 specimens from Beas River, we identified 43 species, belonging to 31 genera, 16 families, and 10 orders. To analyze the genetic divergence and phylogeny of identified species, 485 sequences of Indian origin were retrieved from BOLD, resulting in a dataset of 688 sequences. Our findings consistently revealed a hierarchical increase in the mean K2P genetic divergence within species (0.80%), genus (9.06%), and families (15.35%). Automated Barcode Gap discovery, Neighbour Joining, and Bayesian inference consensus tree methodologies were employed to determine the putative species and their phylogeny, successfully delimiting most of the species with only a few exceptions. The results unveiled six species exhibiting high intra-species divergence (> 2%), suggesting the presence of sibling species and falsely identified sequences on online databases. The present study established the first DNA barcoding-based inventory of freshwater fish species in the Beas River providing comprehensive insights into economically exploited endangered and vulnerable species. In order to ensure the sustainable use of aquatic resources in the Beas River, we recommend the implementation of species measures to protect biodiversity and genetic resources.
Sporosarcina hypophthalmichthys sp. nov. Isolated From Gastrointestinal Tract of Fish Hypophthalmichthys molitrix (Valenciennes, 1844) Meghali Bharti, Monika Sharma, Stanzin Choksket, Himani Khurana, Sneha Siwach, Sonakshi Modeel, Suresh Korpole, Ram Krishan Negi Journal of Basic Microbiology, 2024 A rod‐shaped, motile, Gram‐stain‐positive bacterial strain RKN2T, was isolated from gut of silver carp (Hypophthalmichthys molitrix) residing in Gobindsagar reservoir, Himachal Pradesh, India. Having the greatest sequence similarity to Sporosarcina koreensis F73T (98.51%), Sporosarcina luteola Y1T (98.4%) and Sporosarcina aquimarina SW28T (98.36%), the 16S rRNA gene phylogeny confirmed the belonging of strain RKN2T to genus Sporosarcina. Digital DNA‐DNA hybridization values were 21.7%, 20.6%, and 19.2%, and average nucleotide identity values were 76.42%, 80.16%, 76.51%, of strain RKN2T with Sporosarcina koreensis F73T, Sporosarcina luteola Y1T, and Sporosarcina aquimarina SW28T, respectively. The genomic analysis of strain RKN2T showed various biological properties including nitrate reduction, genes responsible for carbohydrate‐active enzymes production, antimicrobial compounds, as well as potential metabolism of aromatic compounds and heavy metals. G+C composition of RKN2T genome was 52.7%. This strain can grow in temperatures between 10°C and 40°C (optimum, 28°C–30°C), NaCl concentrations up to 6.0% (w/v), and 6.0–8.0 (optimum, 6.5–7.5) pH range. MK‐7 was the dominant respiratory quinone, A‐4 type cell wall peptidoglycan was present with anteiso‐C15:0, iso‐C15: 0, and anteiso‐C17:0 being the major fatty acids and Lys‐Glu being main amino acids. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were the strain RKN2T's three main polar lipids. The strain is a novel species under genus Sporosarcina based on polyphasic approach and the name Sporosarcina hypophthalmichthys sp. nov. is given for strain RKN2T. RKN2T is a type strain (= MCC 4365T = JCM34522T = CCM9112T).
Emerging Role of Gut Microbiome in Cancer Immunotherapy Meghali Bharti, Sonakshi Modeel, Sheetal Yadav, Pankaj Yadav, Sneha Siwach, Padma Dolkar, Shekhar Nagar, Tarana Negi, Ram Krishan Negi Role of Microbes in Sustainable Development Human Health and Diseases, 2023
Length-weight relationship and condition factor of Labeo rohita and Hypophthalmichthys molitrix Research Journal of Pharmaceutical Biological and Chemical Sciences, 2015
Fish diversity in glacial and spring-fed water bodies of Champawat district in the Kumaon region of Uttarakhand state, India Journal of Sustainability Science and Management, 2009
RECENT SCHOLAR PUBLICATIONS
Environmental Drivers and Bioaccumulation Pathways of Microplastics in Freshwater Fish from the River Yamuna, India S Siwach, P Dolkar, A Yadav, A Atri, M Chaurasia, P Yadav, ... Preprints , 2026 2026
A novel non-invasive imaging technique for mapping microplastic accumulation and distribution in different organ systems of Indian major carp Labeo rohita (Ham. 1822) S Siwach, A Singh, S Paul, V Gupta, I Gupta, RK Negi Current Research in Toxicology, 100294 , 2026 2026
Emerging risk factors and the role of gut microbiota in immunomodulation and therapeutic implications in colorectal cancer S Modeel, S Siwach, P Dolkar, M Chaurasia, P Yadav, A Atri, A Yadav, ... Cancer Pathogenesis and Therapy 4 (01), 14-30 , 2026 2026 Citations: 12
Life on Planet: Its Origin and Expansion Across Earth’s Ecosystem RC Sobti, I Sharma, RK Negi, S Modeel Biotechnology Innovations for a Sustainable Future: Integrating Clean Energy … , 2026 2026 Citations: 1
Mitochondrial Perspective on Species Complexes and Evolutionary Dynamics Within Genus Channa S Modeel, M Chaurasia, S Siwach, P Dolkar, RK Negi, RK Negi Biochemical Genetics, 1-25 , 2025 2025 Citations: 1
DNA-based identification of fishes: A review of barcoding methods and their efficiency assessment S MODEEL, BD JOSHI, A YADAV, T NEGI, RK NEGI Iranian Journal of Ichthyology 12 (1), 66-89 , 2025 2025 Citations: 2
Metagenomic analysis of metal (loid) s resistance genes and its environmental applications P Dolkar, S Modeel, S Siwach, P Yadav, M Chaurasia, L Themchurin, ... Advances in Applied Microbiology 132, 123-168 , 2025 2025 Citations: 1
Sustainable aquaculture: A blueprint for achieving zero hunger S Siwach, M Chaurasia, P Dolkar, A Yadav, P Yadav, L Themchuirin, ... Biotechnology innovations and sustainability for zero hunger, 136-150 , 2025 2025 Citations: 3
Sporosarcina hypophthalmichthys sp. nov. Isolated From Gastrointestinal Tract of Fish Hypophthalmichthys molitrix (Valenciennes, 1844) M Bharti, M Sharma, S Choksket, H Khurana, S Siwach, S Modeel, ... Journal of basic microbiology 64 (12), e2400226 , 2024 2024 Citations: 2
Comparative analyses of gut microbiota reveal ammonia detoxification and nitrogen assimilation in Cyprinus carpio var. specularis C Talwar, S Nagar, RK Negi Folia Microbiologica 69 (5), 1029-1041 , 2024 2024 Citations: 1
Challenges and effective tracking down strategies of antibiotic contamination in aquatic ecosystem P Dolkar, M Sharma, S Modeel, S Yadav, S Siwach, M Bharti, P Yadav, ... Environmental Science and Pollution Research 31 (44), 55935-55957 , 2024 2024 Citations: 7
Unveiling the ecotoxicological impact of microplastics on organisms-the persistent organic pollutant (POP): A comprehensive review S Siwach, M Bharti, S Yadav, P Dolkar, S Modeel, P Yadav, T Negi, ... Journal of Contaminant Hydrology 266, 104397 , 2024 2024 Citations: 25
Role of science and technology for sustainable aquaculture development and aquatic ecosystem management S Modeel, P Dolkar, S Siwach, P Yadav, RK Negi Role of Science and Technology for Sustainable Future: Volume 1: Sustainable … , 2024 2024 Citations: 9
Integrated multi-platform approaches to gain insights into ecosystem’s fundamental ecology and habitat specific alterations S Nagar, C Talwar, RK Negi bioRxiv, 2024.06. 07.597995 , 2024 2024
A comprehensive DNA barcoding of Indian freshwater fishes of the Indus River system, Beas S Modeel, RK Negi, M Sharma, P Dolkar, S Yadav, S Siwach, P Yadav, ... Scientific reports 14 (1), 2763 , 2024 2024 Citations: 28
Adaptive evolution of Sphingopyxis sp. MC4 conferred degradation potential for persistent β-and δ-Hexachlorocyclohexane (HCH) isomers M Sharma, DN Singh, G Uttam, P Sharma, SA Meena, AK Verma, ... Journal of Hazardous Materials 461, 132545 , 2024 2024 Citations: 4
Emerging Role of Gut Microbiome in Cancer Immunotherapy M Bharti, S Modeel, S Yadav, P Yadav, S Siwach, P Dolkar, S Nagar, ... Role of Microbes in Sustainable Development: Human Health and Diseases, 409-427 , 2023 2023
Taxonomy, distribution, biology and conservation of vulnerable snow trout Schizothorax richardsonii (Actinopterygii: Cyprinidae: Schizothoracinae) in the Himalayan and sub … M BHARTI, S NAGAR, P YADAV, S SIWACH, P DOLKAR, S YADAV, ... Iranian Journal of Ichthyology 10 (1), 8-27 , 2023 2023 Citations: 5
Riverine pollution influences the intraspecific variation in the gut microbiome of an invasive fish, Cyprinus carpio (Linn., 1758) M Bharti, S Nagar, RK Negi 3 Biotech 13 (10), 320 , 2023 2023 Citations: 2
Correction to: Mitochondrial DNA reveals shallow population genetic structure in economically important Cyprinid fish Labeo rohita (Hamilton, 1822) from South and Southeast Asia S Modeel, BD Joshi, S Yadav, M Bharti, RK Negi Molecular Biology Reports 50 (7), 6309-6309 , 2023 2023 Citations: 1
MOST CITED SCHOLAR PUBLICATIONS
Fish gut microbiome: current approaches and future perspectives C Talwar, S Nagar, R Lal, RK Negi Indian journal of microbiology 58 (4), 397-414 , 2018 2018 Citations: 330
The genus Sphingopyxis: Systematics, ecology, and bioremediation potential-A review M Sharma, H Khurana, DN Singh, RK Negi Journal of Environmental Management 280, 111744 , 2021 2021 Citations: 157
Defining the Environmental Adaptations of Genus Devosia: Insights into its Expansive Short Peptide Transport System and Positively Selected Genes C Talwar, S Nagar, R Kumar, J Scaria, R Lal, RK Negi Scientific reports 10 (1), 1151 , 2020 2020 Citations: 138
Species diversity, abundance and distribution of fish community and conservation status of Tons river of Uttarakhand State, India RK Negi, S Mamgain Journal of Fisheries and Aquatic Science 8 (5), 617-626 , 2013 2013 Citations: 88
Comparative Genomic Analysis Reveals Habitat-Specific Genes and Regulatory Hubs within the Genus Novosphingobium R Kumar, H Verma, S Haider, A Bajaj, U Sood, K Ponnusamy, S Nagar, ... MSystems 2 (3), 10.1128/msystems. 00020-17 , 2017 2017 Citations: 71
Microbial taxonomy in the era of OMICS: application of DNA sequences, computational tools and techniques NK Mahato, V Gupta, P Singh, R Kumari, H Verma, C Tripathi, P Rani, ... Antonie Van Leeuwenhoek 110 (10), 1357-1371 , 2017 2017 Citations: 70
Comparative genomic analysis of rapidly evolving SARS-CoV-2 reveals mosaic pattern of phylogeographical distribution R Kumar, H Verma, N Singhvi, U Sood, V Gupta, M Singh, R Kumari, ... Msystems 5 (4), 10.1128/msystems. 00505-20 , 2020 2020 Citations: 59
Seasonal variation in benthic macro-invertebrates and their correlation with the environmental variables in a freshwater stream in Garhwal region (India) PC Joshi, RK Negi, T Negi Life Science Journal 4 (4), 85-89 , 2007 2007 Citations: 46
Morphological and molecular characterization of Neogastrostyla aqua nov. gen., nov. spec.(Ciliophora, Hypotrichia) from River Yamuna, Delhi; comparison with Gastrostyla-like genera H Kaur, RK Negi, K Kamra European journal of protistology 68, 68-79 , 2019 2019 Citations: 44
Gut microbiome of endangered Tor putitora (Ham.) as a reservoir of antibiotic resistance genes and pathogens associated with fish health H Khurana, DN Singh, A Singh, Y Singh, R Lal, RK Negi BMC microbiology 20 (1), 249 , 2020 2020 Citations: 40
River of garhwal himalaya uttarakhand RK Negi, S Mamgain Pakistan Journal of Biological Sciences 16 (22), 1510-1516 , 2013 2013 Citations: 40
Analysis of morphometric characters of Schizothorax richardsonii (Gray 1832) from the Uttarkashi District of Uttarakhand State, India RK Negi, T Negi Journal of Biological Sciences 10 (6), 536-540 , 2010 2010 Citations: 40
Comparative genomics of Sphingopyxis spp. unravelled functional attributes H Verma, GG Dhingra, M Sharma, V Gupta, RK Negi, Y Singh, R Lal Genomics 112 (2), 1956-1969 , 2020 2020 Citations: 36
Genomic insights into the phylogeny of Bacillus strains and elucidation of their secondary metabolic potential H Khurana, M Sharma, H Verma, BS Lopes, R Lal, RK Negi Genomics 112 (5), 3191-3200 , 2020 2020 Citations: 34
A comprehensive DNA barcoding of Indian freshwater fishes of the Indus River system, Beas S Modeel, RK Negi, M Sharma, P Dolkar, S Yadav, S Siwach, P Yadav, ... Scientific reports 14 (1), 2763 , 2024 2024 Citations: 28
Unveiling the ecotoxicological impact of microplastics on organisms-the persistent organic pollutant (POP): A comprehensive review S Siwach, M Bharti, S Yadav, P Dolkar, S Modeel, P Yadav, T Negi, ... Journal of Contaminant Hydrology 266, 104397 , 2024 2024 Citations: 25
Microbial ecology of sulfur biogeochemical cycling at a mesothermal hot spring atop Northern Himalayas, India S Nagar, C Talwar, M Motelica-Heino, HH Richnow, M Shakarad, R Lal, ... Frontiers in Microbiology 13, 848010 , 2022 2022 Citations: 25
Complete Genome Analysis of Thermus parvatiensis and Comparative Genomics of Thermus spp. Provide Insights into Genetic Variability and Evolution of Natural … C Tripathi, H Mishra, H Khurana, V Dwivedi, K Kamra, RK Negi, R Lal Frontiers in Microbiology 8, 1410 , 2017 2017 Citations: 25
Seasonal assessment of heavy metal pollution in water and sediment of fish pond at Bhagwanpur, Roorkee (UK), India A Maurya, T Negi, RK Negi Asian Journal of Animal Sciences 12 (1), 16-22 , 2018 2018 Citations: 24
A study on stream morphology of some selected streams hill streams of district Nainital with special reference to its biotic communities RK Negi, BD Joshi, T Negi, P Chand Proceedings of National Seminar on Limnology at Jiapur, India , 2007 2007 Citations: 24
