Browsing by Author "Pankaj Kumar Rai"

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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.
Biohydrogen production from microalgal sources
(Elsevier, 2025) Prabhakar Singh; Sakshi Singh; Pankaj Kumar Rai; Arvindkumar Kumar Singh
The global depletion of fossil fuel reserves and associated environmental challenges have shifted the focus to investigating alternative renewable energy sources. Microalgae have emerged as promising candidates for biohydrogen production due to their rapid growth and ability to thrive in diverse environmental conditions, including nonarable land, with unique photosynthetic capabilities and carbon dioxide assimilation strategies. Advancements in genetic and metabolic engineering have the potential to improve the photobiological production of hydrogen from microalgae significantly. This improvement involves manipulating specific enzymes, such as hydrogenase and nitrogenase, to modulate competing metabolic pathways to enhance hydrogen yields. The chapter provides a comprehensive overview of the current research on biohydrogen production from microalgae, with challenges and prospects in making it an economically viable approach. © 2025 Elsevier Inc. All rights reserved.
Biological control of tephritid fruit flies Bactrocera spp. in Himachal Pradesh, India
(Horizon e-Publishing Group, 2024) Preety Tomar; Priyanka Thakur; Sangram Singh; Sheikh Shreaz; Sarvesh Rustagi; Pankaj Kumar Rai; Ashok Yadav; Ajar Nath Yadav
Over the years, chemical-based insecticides have been used to enhance crop yield in the agricultural industry. However, the hazards associated with these insecticides have highlighted the need for an alternative method that is economical, eco-friendly, and safe. In this investigation, the efficacy of various biological materials, such as Neem kavach, Beauveria bassiana (Balsamo), and clay, was evaluated against fruit flies under open field conditions. The results revealed that the highest infestation was recorded in the control (71.67 %), while the lowest infestation (25.67 %) was observed in the plot treated with B. bassiana (1.5 %). This was followed by Neem kavach-treated plot (4 %) with an infestation rate of 26.67 %, and the clay-treated plot (15 g/L) with an infestation rate of 38.67 %, after the third spray. The impact of these biological agents on cucumber yield was also evaluated. The highest yield, 9.36 kg/plot, was obtained from the B. bassiana-treated plot, followed by Neem kavach-treated plots with yields of 8.94 and 7.28 kg/plot, respectively. The lowest yield of 4.58 kg/plot was recovered in the untreated plots. These findings suggest that the application of these biological agents is highly effective, as they repel egg-laying (oviposition deterrence), thereby minimizing fruit infestation and maximizing yield profit. Copyright: © The Author(s).
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.
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.
Temporal variations in microcystin-producing cells and microcystin concentrations in two fresh water ponds
(Elsevier Ltd, 2015) Shweta Singh; Pankaj Kumar Rai; Rocky Chau; Alok Kumar Ravi; Brett A. Neilan; Ravi Kumar Asthana
The relationship between microcystin production, microcystin-producing cyanobacteria, including Microcystis spp., and various biological and physicochemical parameters in Sankuldhara and Lakshmikund, situated in the same geographical area was studied over a period of 1.5 years. Seasonal variation in cyanobacterial 16S rRNA, Microcystis spp. 16S rRNA, mcyA and mcyB genes were quantitatively determined by real-time PCR. Microcystis was the dominant microcystin producer in both study sites constituting 67% and 97% of the total microcystin-producing cyanobacteria at Sankuldhara and Lakshmikund, respectively. Microcystin concentrations were 2.19-39.60μg/L and 15.22-128.14μg/L at Sankuldhara and Lakshmikund, respectively, as determined by LC-MS. Principal component analysis revealed a strong positive correlation between microcystin concentration and the copy number of mcyA and mcyB, chlorophyll a and cyanobacterial biomass at both sites. The higher microcystin concentrations in Lakshmikund pond were attributed to the high copy number of mcy genes present coupled with the pond's eutrophication status, as indicated by high total algal biomass, high chlorophyll a content, high nutrient load and low DO. Therefore, a significant difference in microcystin concentrations, correlating with these various biological and physicochemical parameters, confirms the importance of local environmental variables in the overall regulation of microcystins production. © 2014 Elsevier Ltd.
Utilization of microalgal biomass as a source of bioenergy
(Nova Science Publishers, Inc., 2018) Pankaj Kumar Rai; Abudukeremu Kadier; Manish Kumar; Sureshwar Prashad Singh
The consumption of fossil fuels and accumulation of greenhouse gases in the environment attract researchers worldwide to focus more on developing an alternative renewable and potentially carbon neutral biofuel. Microalgae have the potential to solve both the issues simultaneously by CO2 sequestration from the environment to increase its biomass and use of this biomass for biofuels production. Knowing the potential of photosynthetic microalgae, research studies focusing their utilization as feedstock for biofuel production has been carried out recently by many groups. Microalgae have added advantage that it can grow in waste water, are photosynthetic and unlike first and second generation biofuels it does not put strain on food market or changes in land use. This chapter reviews microalgae use for biofuels generation along with their large scale biomass production, harvesting techniques, pretreatment/processing and conversion of microalgae to biofuel using biochemical process. © 2018 by Nova Science Publishers, Inc. All rights reserved.