Browsing by Author "Naveen Kumar Sharma"

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Airborne algae: Their present status and relevance
(2007) Naveen Kumar Sharma; Ashwani Kumar Rai; Surendra Singh; Richard Malcolm Brown Jr.
Ongoing climatic changes coupled with various natural processes and the outcomes of human activities are not only loading the atmosphere with diverse kinds of biological particles but also changing their prevalence and spatial distribution. Despite having considerable ecological and economic significance, including their possible impact on human health, airborne algae are the least-studied organisms in both aerobiological and phycological studies. The present review has been written to bring together all available information, including a brief survey of the literature, the ecology of airborne algae, mechanisms involved in their aerosolization, the role of environmental factors in shaping the structure and composition of aero-algal flora, and other significant information associated with airborne algae. This review provides information on methodological approaches and related problems, along with suggestions for areas of future research on airborne algae. © 2007 Phycological Society of America.
Allergenicity of airborne cyanobacteria Phormidium fragile and Nostoc muscorum
(2008) Naveen Kumar Sharma; Ashwani K. Rai
In recent times, airborne microorganisms and their constituents have become prominent safety and health concern. Ongoing climatic changes coupled with unwarranted human activities have significantly deteriorated the ambient air quality. In certain environments, airborne algae contribute significantly to the total biological load of the atmosphere, hitherto dominated by bacteria and fungi. Present study was aimed to investigate the allergenic potency of two frequent viable algal forms i.e., Phormidium fragile and Nostoc muscorum found in the atmosphere of Varanasi City, India. To test the allergenic potency, crude extracts of these strains were subjected to intra-dermal allergy test and subsequent leukocyte counts, which revealed their allergenic nature. Both the species varied in their allergenic potency. N. muscorum appeared to be more allergenic than P. fragile. However, when the allergens were mixed in equal amounts, the severity of allergenicity increased significantly. A limited pattern of cross-reactivity between the species was also evident. © 2006 Elsevier Inc. All rights reserved.
Application of constructed wetland; a natural treatment system for environmentally sustainable domestic sewage treatment
(Elsevier, 2021) Virendra Kumar Mishra; Reetika Shukla; Naveen Kumar Sharma
Water resources throughout the world are severely threatened from different pollutants released into water bodies, thereby causing water pollution. Sewage is wastewater released by household drains, residential apartments, communities living in urban agglomerations, and contains of human fecal matter and large volume of water. Chemically, it contains suspended and dissolved solids (TSS and TDS), dissolved organics, nutrients (nitrate, ammonia, and phosphorus), minerals, and pathogens (bacteria, protozoans, viruses, helminth eggs), gases like H2S, CO2, CH4, and NH3, etc. Almost all the sewage ultimately finds its way to the aquatic ecosystems and is a major source of water pollution. There are several wastewater treatment technologies; however, Constructed Wetlands (CW) have emerged as an eco-friendly, economically viable option for sustainable treatment of sewage. CWs are manmade or engineered wetlands that are designed built and operated to harness the functions of natural wetlands for the treatment of various pollutants from wastewater. Constructed wetland is a well-known technology in the different parts of the world especially in European countries for the treatment of domestic sewage. But, in Indian context such studies are very limited and this technology can be applied to even the remote areas of the country where capital and energy inputs are the major issues related to sewage treatment. Under present chapter, we have reviewed some important studies conducted worldwide dealing with application of CWs for the treatment of the sewage. We have also reviewed such studies conducted in Indian context. Our study suggests that the CWs are a natural technology of wastewater treatment and it had been a successful technology in the Europe; however, its use has been very limited in India context and more studies can establish this technology as a viable option for sewage treatment in Indian context. © 2021 Elsevier Inc. All rights reserved.
Diversity and seasonal variation of viable algal particles in the atmosphere of a subtropical city in India
(2006) Naveen Kumar Sharma; Surendra Singh; Ashwani K. Rai
To characterize the airborne algal diversity in a populous subtropical urban environment, sampling was done at a height of 2.5 m, the normal human breathing zone. Results indicated that airborne algae are the permanent constituent of Varanasi city atmosphere. The nature, composition, and relative ratio of constituting groups differed among sampling sites. Cyanobacteria, possibly due to their broad ecological distribution, dominate the fluctuating climates of subtropical regions such as Varanasi. The majority of the airborne algae were of local origin, indicating short-distance transport of the algae. Soilborne algae constituted the bulk of aeroalgal flora. This might be due to their ability to withstand the dehydrating effect of the atmosphere. Composition of the aeroalgal community also exhibited seasonal variation along with the change in climatic condition of the area. Thus, the physiological ability of an algal group to tolerate different types of abiotic stresses and the climatic conditions of the area appeared to be the two major factors responsible for regulating the structure of the aeroalgal community in the air. © 2006 Elsevier Inc. All rights reserved.
Effect of fluorescent Pseudomonas on plant growth promotion of Aloe vera
(Taylor and Francis Ltd., 2024) Anuradha Rai; Vaibhav Kumar Singh; Naveen Kumar Sharma; Jay Shankar Singh; Vinod Kumar Singh; Brahma Swaroop Dwivedi; Pradeep Kumar Rai
Modern agriculture practices heavily depend on the application of chemical fertilizers and continuous application disturbs the soil quality and health. Fluorescent Pseudomonas are the well characterized group of bacteria proficient in plant growth promotion and have excellent phosphate solubilizing abilities and solubilize insoluble phosphate to plants available form via secretion of organic acids. This study focused on the phosphate solubilization ability of Pseudomonas, arouse of Aloin-A molecule, gluconic acid production, as well as biometric parameters of key medicinal plant, the Aloe vera (Aloe barbadensis). Two strains (P. putida and Pseudomonas sp.) were found very effective PSBs and solubilized 236.73 and 153.73 mg L−1 phosphate, respectively. High-performance liquid chromatography analysis (HPLC) showed the production of gluconic acid (GA). P. putida and P. sp. produced 23970 ± 231 and 21538 ± 129 mg L−1 GA, respectively. Inoculation of the plants with consortium of P. putida and Pseudomonas sp. enhanced the plant growth, soil available P and phosphate uptake in plants than individual inoculation. An increase in aloin-A content (18.15 and 28.71 fold) was recorded in A. barbadensis treated with a PSB consortium in a soil amended without and with TCP (tricalcium phosphate), respectively. P-uptake ultimately enhances the aloin-A synthesis and biomass of plant. Therefore, agronomic attributes of Aloe vera plants can be improved for used as a medicinal plant through application of potent Fluorescent Pseudomonas. © 2023 Taylor & Francis Group, LLC.
Green-synthesized nanoparticles for treatment of wastewater: An environmentally sustainable pollution remediation technology
(Elsevier, 2021) Amit Kumar Patel; Deepak Gupta; Anubhuti Singh; Virendra Kumar Mishra; Naveen Kumar Sharma
Water is vital for life on Earth, and its unavailability or poor quality has severe consequences for all aspects of human life, including food, health, and environment. Anthropogenic activities have caused widespread pollution of water resources worldwide. Although some remediation methods and techniques have been developed, considering the extent, quantity, and varied nature of pollutants, new and sustainable technologies are urgent needed to remediate polluted water and wastewater. In recent times, the use of nanomaterials for the treatment of wastewater has gained considerable importance owing to their high accuracy and precise remediation. Nanoparticles (NPs) exhibit enhanced chemical reactivity, high surface area, lower costs and energy requirements, and efficient regeneration for reuse, making them ideal materials for wastewater treatment. The conventional method of NP production is hazardous, and application of volatile chemicals results in secondary pollution, yet biogenic NPs are inexpensive and environmentally safe. Plants, bacteria, algae, and fungi produce a range of alkaloids, flavonoids, carbohydrates, polymers, proteins, and numerous antioxidants that are effectively used as capping and stabilizing agents in NP synthesis. In this chapter, we discuss the synthesis of biogenic NPs from different organisms and their potential applications in wastewater remediation. Moreover, to supplement the existing research gaps, different strategies are also recommended. © 2021 Elsevier Inc. All rights reserved.
Growth and cellular ion content of a salt-sensitive symbiotic system Azolla pinnata-Anabaena azollae under NaCl stress
(Elsevier GmbH, 2006) Vandna Rai; Naveen Kumar Sharma; Ashwani K. Rai
Salinity, at a concentration of 10 mM NaCl affected the growth of Azolla pinnata-Anabaena azollae association and became lethal at 40 mM. Plants exposed up to 30 mM NaCl exhibited longer roots than the control, especially during the beginning of incubation. Average root number in plants exposed to 10 and 20 mM NaCl remained almost the same as in control. A further rise in NaCl concentration to 30 mM reduced the root number, and roots shed off at 40 mM NaCl. Presence of NaCl in the nutrient solution increased the cellular Na+ of the intact association exhibiting differential accumulation by individual partners, while it reduced the cellular Ca2+level. However, cellular K+ content did not show significant change. Cellular Na+ based on fresh weight of respective individual partners (host tissues and cyanobiont) remained higher in the host tissues than the cyanobiont, while reverse was true for K+ and Ca2+ contents. The contribution of A. azollae in the total cellular ion content of the association was a little because of meagre contribution of the cyanobiont mass (19-21%). High salt sensitivity of Azolla-Anabaena complex is due to an inability of the association to maintain low Na+ and high Ca2+ cellular level. © 2005 Elsevier GmbH. All rights reserved.
Indian Agriculture: Challenges, Priorities and Solutions
(Springer Science+Business Media, 2025) Naveen Kumar Sharma; Pradeep Kumar Rai; Dinesh Chandra Rai
This edited volume examines the challenges and solutions in the intricate landscape of Indian agriculture and global trade. It explores the historical shifts from an industry-driven to agrarian economy, followed by rapid urbanization in the latter half of the 20th century. Modern agri-business is a global phenomenon not only affected by local and regional factors but also by global policies directed by global agencies. This book focuses on problems commonly associated with the advancement of agriculture in India, as well as issues arising out of global agricultural trade. The book contains chapters on associated problems, some priority issues, and approaches that could be used to overcome these limitations. Focused on rural India, the book underscores the critical role of agriculture, contributing a major part to the national income. The book highlights the economic opportunities arising from agriculture, emphasizing the need for sustainable practices given ecological, cultural, and socio-economic impacts. Addressing the complexities, the book advocates for diversification, adaptive varieties, and technological integration, including biotechnology and information technologies, to ensure the sustainability of agriculture. It also stresses the urgency of coherent national policies for soil and water resource use, marketing, business management, climate impacts, and more. It outlines key interventions and frameworks designed to guide actions on food security and nutrition, making a case for India's crucial role in global food production and supply chain systems. The book has been written and edited by leading researchers of the respective fields. It is a useful resource for students, researchers, academicians as well as farmers and policymakers. © 2025 The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Introduction
(Springer Science+Business Media, 2025) Naveen Kumar Sharma; Pradeep Kumar Rai; Dinesh Chandra Rai
[No abstract available]
Microbial interactions in the arsenic cycle: Adoptive strategies and applications in environmental management
(Springer Science and Business Media, LLC, 2013) Umesh Praveen Dhuldhaj; Ishwar Chandra Yadav; Surendra Singh; Naveen Kumar Sharma
The term "arsenic" is derived from the Persian word "zarnikh" meaning "yellow orpiment" (As2S 3) (Rensing and Rosen 2009). Arsenic (As) is a metalloid (Table 1) and has a single naturally occurring isotope As75 (Rensing and Rosen 2009). It occurs in four primary oxidation states, viz., arsenate [As(V)], arsenite [As(III)], elemental arsenic [As(0)], and arsenide [As(-III)]. Arsenic compounds have no known biological roles. Formerly, As found applications in medicine in ancient civilizations (Datta et al. 1979). It has also been used in the cosmetic and agriculture industries (insecticide, desiccant, rodenticide, and herbicide). However, in recent times, the element has acquired notoriety for its toxicity to humans. The Agency for Toxic Substances and Disease Registry (ATSDR) has included arsenic in the list of "20 most hazardous substances" (Rensing and Rosen 2009). © 2013 Springer Science+Business Media New York.
Physiological, biochemical and molecular responses of the halophilic cyanobacterium Aphanothece halophytica to Pi-deficiency
(2013) Keshwanand Tripathi; Naveen Kumar Sharma; Hakuto Kageyama; Teruhiro Takabe; Ashwani Kumar Rai
We studied the responses of a halophilic cyanobacterium Aphanothece halophytica at surplus (normal composition of growth medium containing 125 μM PO43-), sufficient (the minimum concentration supporting optimal growth, 22 μM PO43-) and deficient (no external supply of Pi) concentrations of inorganic phosphate (Pi). The cyanobacterium was able to grow well in Pi-deficient conditions until the end of incubation (14 days), though at a marginally reduced rate. The cellular P-quota in Pi-surplus cells at the end of incubation was 2.7 times that of their initial P-quota (0.75 μmol mg protein-1), and remained fairly high (0.442 μmol mg protein-1) even in Pi-deficient medium. However, cultures growing in Pi-sufficient medium (22 μM PO43-), upon transfer to Pi-deficient medium, exhibited a rapid decline in cellular P level. Furthermore, cells growing in Pi-surplus medium showed a rapid efflux of P into the external medium. Aphanothece halophytica exhibited a biphasic phosphate transport system involving both high- (Ks 2.06 μM) and low-affinity (Ks 17.85 μM) transporters. Cyanobacterial cells maintained a basal level (constitutively expressed and not affected by Pi availability) of alkaline phosphatase (APase) activity, which increased 5-7-fold under Pi-deficiency. Supplementation of phosphate to the medium caused gradual decline in the enzyme activity to the basal level. Pi-deficient cells showed an enhanced level of transcripts for PPi-dependent glycolytic enzymes. Though moderate, Pi-deficiency affected the respiration, photosynthetic rate and electron transport chain activity negatively. PS II activity was most sensitive to Pi-deficiency, followed by PSI and whole chain. Pi-replete A. halophytica cells showed a single high-affinity nitrate transport system. However, deficiency of Pi reduced the nitrate and nitrite reductase activities. © 2013 © British Phycological Society.
Recombinant glycinebetaine improves metabolic activities, ionic balance and salt tolerance in diazotrophic freshwater cyanobacteria
(Elsevier B.V., 2015) Prashant Swapnil; Meenakshi Singh; Sweta Singh; Naveen Kumar Sharma; Ashwani K. Rai
To find out the physiologic mechanisms contributing to increased tolerance to salinity by glycinebetaine in diazoptrophic cyanobacteria, methyl transferase gene ApGSMT-DMT catalyzing glycinebetaine synthesis in Aphanothece halophytica was transferred into N2-fixing filamentous cyanobacteria Anabaena PCC7120 and Anabaena doliolum. The transformants synthesized/accumulated significant amount of glycinebetaine. Under salt-stress (0.1M NaCl), the transformants were more efficient in reducing nitrate and its incorporation into amino compounds compared to wild-types indicating that glycinebetaine not only shielded the enzymes from deleterious effect of salt but enhanced their activities. High photosynthetic rate of ApGSMT-DMT transformants under salt-stress exhibited haloprotection of the photosynthetic machinery, while reduced respiration revealed efficient use of photosynthates. Salinity reduced the electron flow activity of PS II causing damage to cytochrome b6-f complex, which was overcome to an extent by glycinebetaine. The observed limited electrons transport from PSII to PSI under salinity favored additional excitation of PSI resulting in increased electron transport activity of PSI. Salinity reduced the intracellular K+/Na+ and Ca2+/Na+ ratios, while transformants showed the highest K+/Na+ ratio. This attempt to develop salt tolerant N2-fixers can increase the nitrogen availability under saline conditions, and opens the way to transform symbiotic and free-living N2-fixers to increase the salt tolerance and productivity. © 2015 Elsevier B.V.
Study of Phosphate Solubilizing Fluorescent Pseudomonas Recovered from Rhizosphere and Endorhizosphere of Aloe barbadensis (L.)
(Taylor and Francis Ltd., 2023) Anuradha Rai; Naveen Kumar Sharma; Vinod Kumar Singh; Brahma Swaroop Dwivedi; Jay Shankar Singh; Pradeep Kumar Rai
Phosphorus (P) is a key nutrient required by plants for their growth and development. A large part of applied phosphatic fertilizer becomes unavailable due to its fixation in soil. In rhizosphere, fluorescent Pseudomonads are instrumental in phosphate solubilization. We isolated Pseudomonads from the rhizosphere of Aloe barbadensis (L.), and screened them for their plant growth promoting ability such as - solubilization of phosphate, auxin production and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. A total of 307 fluorescent Pseudomonas were isolated and screened, of which, 24 isolates showed a strong phosphate solubilizing ability, ranging from 69.71 to 236.73 µg ml−1. The Indole acetic acid (IAA) production by all 24 isolates varied from 28.44 to 151.99 µg ml−1. However, 17 isolates produced ACC-deaminase ranging from 8.19 to 10.27 µmol mg−1 h−1. Analyses of 16S rRNA gene and Pseudomonas-specific genes grouped the isolates in seven different species of fluorescent Pseudomonas. Genotypic analysis based on 16S rDNA-RFLP using restriction enzymes (HaeIII, AluI and MspI) and BOX-PCR generated unique genotype specific pattern. The results suggested that Pseudomonas diversity has no association with microenvironments and the sampling site of the plants. 16S rRNA gene-based diversity indices revealed great diversity among the fluorescent Pseudomonas recovered from the rhizospheric regions of the Aloe. Due to the above plant growth-promoting traits, fluorescent Pseudomonas can be exploited as bio-inoculants for crops, with minimal damage to the environment. © 2023 Informa UK Limited, trading as Taylor & Francis Group.
Study of soil cyanobacteria along a rural-urban gradient
(Elsevier B.V., 2018) Pradeep Kumar Rai; Anuradha Rai; Naveen Kumar Sharma; Surendra Singh
Urbanization is one of the modern and critical factors adversely affecting global biodiversity. The impact of urbanization on soil microbial diversity has sporadically been studied of cyanobacterial diversity. The present study analyzes morphological as well as molecular diversity of cyanobacteria along a rural-urban gradient using a culture based approach. In total, 22 cyanobacterial morphotypes (14 genera and 21 species) from five orders were reported; dominated by the members of the order Nostocales. In general, cyanobacterial diversity decreased from rural to urban areas; with N2-fixing heterocystous forms dominating the cyanobacterial flora of the urban area. The values of Shannon–Weaver (2.56) and Simpson's (2.32) indices suggested higher cyanobacterial diversity in the rural area compared to that of the sub-urban and urban areas. Statistical analyses established the importance of physico-chemical factors in structuring the cyanobcaterial communities along the gradient with soil characteristics such as – pH, organic carbon, nitrogen and bulk density, directly as well as indirectly. © 2018 Elsevier B.V.
Teaching versus research in higher education institutes: Revisiting the issue
(Indian Academy of Sciences, 2016) Ajeet Kumar Rai; Naveen Kumar Sharma
[No abstract available]
Urbanization reduces overall cyanobacterial abundance but favors heterocystous forms
(Elsevier B.V., 2021) Pradeep Kumar Rai; Anuradha Rai; Naveen Kumar Sharma; Vinod Kumar Singh; Surendra Singh
Managing agricultural land, both in terms of quantity and quality, is one of the major challenges of the world. Urbanization is a powerful human-induced land use transformation that not only affects adversely the availability of arable lands, but also the soil microbial diversity crucial for maintaining fertility and other soil functions. The study reports the change in cyanobacterial diversity and community composition along a rural-urban gradient, through amplicon sequencing using Illumina MiSeq approach. Urbanization significantly altered the diversity, abundance and community composition of cyanobacteria that vary along the gradient. Rural soils had the highest diversity and maximal abundance of uncultured cyanobacteria, followed by sub-urban and urban soils. In general, along the gradient Oscillatoriales (non-heterocystous forms) were the most abundant taxa, while abundance of Nostocales (i.e., heterocyst bearing N2-fixers) increased in the urban soil. The favored growth of specific taxa in urban soils indicates biotic homogenization. The relative dominance of genus Leptolyngbya in urban and sub-urban soils could be used as an indicator of urbanization. © 2021 Elsevier B.V.
Use of biowaste to ameliorate chromium-contaminated soils to improve crop productivity
(Elsevier B.V., 2024) Anuradha Rai; Naveen Kumar Sharma; Vinod Kumar Singh; Ashish Rai; Vipin Kumar; Abhinav Kumar; Jay Shankar Singh; Sanjay Kudesia; Pradeep Kumar Rai
Increasing discharge of untreated industrial effluents has led to high metal loads in different environments. In the recent past Chromium (Cr) has emerged as a severe pollution to soil and aquatic ecosystems. Its global average load in soil is 54 ppm. Chromium has deleterious effects on crops and the subsequent food chain. If ingested, hexavalent chromium [Cr (VI)] is highly carcinogenic to faunal health. Here, we investigate the use of biowaste on chromium-contaminated soils to promote phytostabilization and overall improvement in crop productivity via decreased solubilization, restricted leaching, higher bioavailability of micronutrients, along with the efficient recycling of waste from the environment. Biowaste amendments facilitate complex processes such as stable compound formation after reacting to organic ligands, precipitation on surfaces, and ion exchange phenomenon; to improve fertility, physical health, and microbial activity in soil. The resulting improved soil quality promotes resettlement of vegetation and better plant growth and development. The potency of different biowastes to immobilize the hazardous metal(loid)s depends on their chemical nature, the extent of their degradation by microbes, their reaction in specific soil-type and concerned metal(loid)s. We need to develop different bio-remedial strategies to curtail the Cr-phytotoxicity, and ensure sustainable crop productivity. © 2024 The Authors