Browsing by Author "Jay Kumar"

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Artificial and natural photoprotective compounds
(Nova Science Publishers, Inc., 2018) Garvita Singh; Jay Kumar
A continuous increase in environmental pollutants in the biosphere has lead to substantial loss of stratospheric ozone layer, allowing unavoidable entry of ultraviolet (UV) radiations on the Earths surface. This increase in UV radiations has emerged as one of the major environmental risk factor for non-melanoma skin cancer and its overexposure can cause erythema, edema, photoaging and hyperpigmentation. The most well known way to reduce the incoming UV radiation penetration through skin is topical application of sunscreens, having potential to either absorb or reflect UV by their active molecules for long hours. Based on their photoprotective strategies active molecules in sunscreens are broadly classified as natural or artificial sunscreen. The artificial sunscreen compounds either reflect and scatter UV radiations (inorganic compounds) or have potential to absorb incoming UV radiation and reemit it as heat or light energy (organic compounds). However, photoprotection via artificial sunscreen compounds bear the risk to cause damage to living organism by alterations at genomic and proteomic constitution. Furthermore, their regular use may cause a negative impact on human health. Their continous release in environment is a matter of concern as they are not ecofriendly. The use of natural sunscreen compounds has gained significant attention as they are safe with multiple biological actions on the skin as antioxidants and being cost effective are becoming markets first choice changing the trend towards natural-green cosmetics. Their active constituents act as effective ROS (reactive oxygen species) scavenger and promise protection against oxidative stress, with the broad spectrum of UV absorption, anti-inflammatory, and immunomodulatory properties. With the increasing interest in natural sunscreen formulations, the aim of this chapter is to make a review of the different forms of photoprotective compounds available, emphasizing types and role of natural sunscreens derived from plants, and algae as substitutes for different types of synthetic sunscreen filters. Therefore, further study pertaining to sunscreen knowledge and understanding its response with sun remains important aim. © 2010 by Nova Science Publishers, Inc. All rights reserved.
Cyanobacteria: Applications in Biotechnology
(Elsevier, 2018) Jay Kumar; Divya Singh; Madhu B. Tyagi; Ashok Kumar
Cyanobacteria, the first oxygen-evolving group of photosynthetic Gram-negative prokaryotes, are unique among microbial world and grow in diverse habitats. Cyanobacteria synthesize a vast array of novel secondary metabolites including biologically active compounds with antibacterial, antiviral, antifungal, and anticancer activities. Certain other important metabolites reported from cyanobacteria, include enzymes, toxins, UV-absorbing pigments, and certain fluorescent dyes. Furthermore, biofuel production by cyanobacteria constitutes one of the most promising areas for biotechnological applications. In addition, production of alcohols and isoprenoids, biopolymers, recombinant proteins, and single-cell protein employing modern tools of genetic engineering seems attractive. In the field of agriculture, potent N2-fixing cyanobacteria could be exploited as bio-factory to produce biofertilizer for enriching the fertility of soil. There is a need to develop suitable genome engineering tools in cyanobacteria to produce fuels, value-added compounds, and feedstocks in a sustainable way. In this chapter, an overview of the potential applications of cyanobacteria in various sectors of biotechnology is presented. © 2019 Elsevier Inc. All rights reserved.
Effect of Biofabricated Silver nanoparticles on Growth parameters in Fenugreek (Trigonella foenum-graecum)
(Springer, 2024) Garvita Singh; Anshul Sheokand; Ashi Gupta; Himani Gupta; Jay Kumar; Renu Soni; Varsha K. Singh; Rajeshwar P. Sinha
Plants being the primary producer in the ecosystem and are the most significant source of food and energy for life to sustain; therefore, a better and improved understanding related to the impacts of nanoparticles on plant growth and development needs to be studied. Use of nanotechnology is one of the methods to ensure food security by improving plant growth and productivity. The current study was undertaken to explore interactions of biologically synthesized (from cyanobacterial extract) silver nanoparticles (AgNPs) on growth and development of Trigonella foenum-graecum. Plant responses to AgNPs exposure in features like percentage seed germination, hypocotyl length and root length, chlorophyll content, number of branchlets, number of leaves, number of flowers, pod length, and number of seeds, were examined. The results obtained showed that out of three different concentrations (10 µg/mL, 20 µg/mL and 50 µg/mL) of AgNPs, 10 µg concentration was found to be the most relevant for growth parameters. There was a slight increase in the studied parameters at 20 µg concentration of AgNPs but higher concentration of AgNPs had showed inhibitory effects. The results obtained showed that out of three different concentrations (10 µg/mL, 20 µg/mL and 50 µg/mL) of AgNPs, 10 µg/mL concentration was found to be most relevant in the study of growth parameters. AgNPs at low concentrations (10 µg/mL and 20 µg/mL) showed positive effect on overall development of plant by enhancing the number of branchlets, leaves per plant, number of pods, and seed production. AgNPs caused toxicity to the seedlings at higher concentration and increased exposure time. Other parameters such as early flowering and delayed senescence has also been reported in AgNPs treated plants which can be used for further studies. © The Author(s) under exclusive licence to Society for Plant Research 2024.
Endophytic and epiphytic modes of microbial interactions and benefits
(Springer Singapore, 2017) Jay Kumar; Divya Singh; Paushali Ghosh; Ashok Kumar
Plants and microbes are the important components of ecosystem, and their interactions help in regulating the biogeochemical cycle in the environment. Plant-associated microorganisms include bacteria, fungi, viruses, and some algae. They may be endophytic and/or epiphytic depending upon their location on the host plants. These microbes use host plants for their growth, colonization, and proliferation; however, they offer a variety of benefits to the hosts. Colonization of microorganisms on host plants takes place through air, water, and insects, or they may also be present in germinating plant parts. Endophytic microbial interactions influence the internal part, while epiphytic microbial interactions influence the exterior surface of the plants. These microbes are not harmful to the plants; however, they secrete some beneficial substances which may help in plant growth promotion, resistance to pathogenic microbes, removal of harmful contaminants, and production of secondary metabolites. In such a way, microbes contribute in agricultural crop improvement, food safety, and industries. This chapter briefly deals with the ecology, interactions, and benefits of plant-microbe interaction, especially in the area of sustainable agriculture and crop improvement. © 2017, Springer Nature Singapore Pte Ltd.
Facile and green synthesis of highly dispersed cobalt oxide (Co3O4) nano powder: Characterization and screening of its eco-toxicity
(Elsevier B.V., 2018) Shikha Dubey; Jay Kumar; Ashok Kumar; Yogesh Chandra Sharma
A novel green synthesis of cobalt oxide (Co3O4) nanoparticles using latex of Calotropis procera via simple precipitation method at room temperature was investigated. An extensive characterization of the product was carried out using X-ray diffractometry (XRD), Differential scanning calorimetry (DSC), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and UV–Visible spectroscopy. The results of the characterization confirmed that the synthesized nanomaterial is highly dispersed. TEM analysis revealed that the nano particles are having an average size around 10 nm. The eco-toxic investigation suggested that the particles are non-toxic and safe towards the environment. This green strategy proves to be an effective, fast, simple and cost-effective approach for the synthesis of Co3O4 nanoparticles for various applications. © 2018 The Society of Powder Technology Japan
Isolation of pyomelanin from bacteria and evidences showing its synthesis by 4-hydroxyphenylpyruvate dioxygenase enzyme encoded by hppD gene
(Elsevier B.V., 2018) Divya Singh; Jay Kumar; Ashok Kumar
Various types of pigments are produced by different bacterial species and play multifunctional role including their role as a protective agent against environmental stresses. The present study deals with the isolation and characterization of melanin pigment from bacteria. Three isolates showed pigment production and identified as Klebsiella pneumoniae S-1, Alcaligenes faecalis PBI and Enterobacter sp. ABI on the basis of 16S rRNA gene sequencing. The maximum production of brown pigment (λmax 405 nm) was attained after 6 days of growth in liquid medium containing 3 g L−1 of L-tyrosine. Solubility test, FTIR and ESI-MS analysis suggested the nature of pigment as melanin. Identity of pigment type from all the three bacteria was made by HPLC analysis, results showed the presence of homogentisic acid (HGA), a precursor of pyomelanin. All the bacteria showed high activity of 4-hydroxyphenylpyruvate dioxygenase (HPPD) suggesting its role in HGA synthesis. PCR amplification of gene(s) also showed the presence of 4-hydroxyphenylpyruvate dioxygenase (hppD) gene coding for HPPD enzyme suggesting its role in pyomelanin synthesis. This study deals with only three bacterial isolates, isolation of such pigment from a large number of bacteria growing in harsh habitats may prove useful in finding novel type of melanin. © 2018 Elsevier B.V.
Plant Growth-Promoting Rhizobacteria (PGPRs): Functions and benefits
(Springer Singapore, 2019) Divya Singh; Paushali Ghosh; Jay Kumar; Ashok Kumar
Microorganisms have a fundamental contribution in the growth and development of plants by influencing their physiology and metabolism. Plant growth-promoting rhizobacteria (PGPRs) have been recognized as an important coevolutionary factor between plants and microbes. PGPRs show antagonistic and synergistic interactions with pathogenic microbes and plants, respectively. PGPRs produce a vast array of secondary compounds which facilitate agricultural yield as well as environmental cleanup. Since the extensive uses of chemical fertilizers and pesticides have caused deleterious impacts on almost all life forms in nature, researchers have shifted their attention on PGPRs throughout the world to improve the crop productivity. Moreover, the cost-effective and eco-friendly nature of PGPR makes them desirable candidate for application in crop disease management and integrated nutrient management. As such, now attention is also being focused to explore plant microbiome in order to identify new strains of microbes that can be used for enhancing plant growth and health in a sustainable way. The present chapter highlights the functions of PGPRs with special reference to its properties such as nutrient acquisition, mineral solubilization, siderophore production, phytohormone production, and tolerance to biotic as well as abiotic stresses. It also focuses on the benefits of PGPRs as biofertilizer, phytostimulant, and biocontrol agents and in rhizoremediation. © Springer Nature Singapore Pte Ltd. 2019.
Proteomic De-regulation in cyanobacteria in response to abiotic stresses
(Frontiers Media S.A., 2019) Piyoosh Kumar Babele; Jay Kumar; Venkatesh Chaturvedi
Cyanobacteria are oxygenic photoautotrophs, exhibiting a cosmopolitan distribution in almost all possible environments and are significantly responsible for half of the global net primary productivity. They are well adapted to the diverse environments including harsh conditions by evolving a range of fascinating repertoires of unique biomolecules and secondary metabolites to support their growth and survival. These phototrophs are proved as excellent models for unraveling the mysteries of basic biochemical and physiological processes taking place in higher plants. Several known species of cyanobacteria have tremendous biotechnological applications in diverse fields such as biofuels, biopolymers, secondary metabolites and much more. Due to their potential biotechnological and commercial applications in various fields, there is an imperative need to engineer robust cyanobacteria in such a way that they can tolerate and acclimatize to ever-changing environmental conditions. Adaptations to stress are mainly governed by a precise gene regulation pathways resulting in the expression of novel protein/enzymes and metabolites. Despite the demand, till date few proteins/enzymes have been identified which play a potential role in improving tolerance against abiotic stresses. Therefore, it is utmost important to study environmental stress responses related to post-genomic investigations, including proteomic changes employing advanced proteomics, synthetic and structural biology workflows. In this respect, the study of stress proteomics offers exclusive advantages to scientists working on these aspects. Advancements on these fields could be helpful in dissecting, characterization and manipulation of physiological and metabolic systems of cyanobacteria to understand the stress induced proteomic responses. Till date, it remains ambiguous how cyanobacteria perceive changes in the ambient environment that lead to the stress-induced proteins thus metabolic deregulation. This review briefly describes the current major findings in the fields of proteome research on the cyanobacteria under various abiotic stresses. These findings may improve and advance the information on the role of different class of proteins associated with the mechanism(s) of stress mitigation in cyanobacteria under harsh environmental conditions. Copyright © 2019 Babele, Kumar and Chaturvedi.
Ultraviolet-B Radiation Stress-Induced Toxicity and Alterations in Proteome of Deinococcus radiodurans
(S. Karger AG, 2021) Jay Kumar; Paushali Ghosh; Ashok Kumar
Deinococcus radiodurans is a polyextremophilic bacterium capable to survive and grow at high doses of ionizing radiation. Besides resistance to ionizing radiation, the bacterium is also resistant to toxic chemicals and desiccation. This study deals with the effects of non-ionizing radiation (ultraviolet-B) on survival, alterations in proteomic profile, and gene expression in D. radiodurans. Exposure of culture to UV-B caused decrease in the percentage survival with increasing duration, complete killing occurred after 16 h. D. radiodurans also showed enhancement in the generation of reactive oxygen species and activities of antioxidative enzymes. Separation of proteins by 2-dimensional gel electrophoresis revealed major changes in number and abundance of different proteins. Twenty-eight differentially abundant protein spots were identified by MALDI-TOF MS/MS analysis and divided into 8 groups including unknown proteins. Gene expression of a few identified proteins was also analyzed employing qRT-PCR, which showed differential expression corresponding to the respective proteins. In silico analysis of certain hypothetical proteins (HPs) suggested that these are novel and as yet not reported from D. radiodurans subjected to UV-B stress. These HPs may prove useful in future studies especially for assessing their significance in the adaptation and management of stress responses against UV-B stress. © 2020 S. Karger AG, Basel.
UV-B radiation stress causes alterations in whole cell protein profile and expression of certain genes in the rice phyllospheric bacterium Enterobacter cloacae
(Frontiers Media S.A., 2016) Jay Kumar; Piyoosh K. Babele; Divya Singh; Ashok Kumar
Among the different types of UV radiation, UV-B radiation (280-315 nm) has gained much attention mainly due to its increasing incidence on the Earth's surface leading to imbalances in natural ecosystems. This study deals with the effects of UV-B radiation on the proteome and gene expression in a rice phyllospheric bacterium, Enterobacter cloacae. Of the five bacteria isolated from rice leaves, E. cloacae showed the highest level of resistance to UV-B and total killing occurred after 8 h of continuous exposure to UV-B. Reactive oxygen species were induced by UV-B exposure and increased with increasing duration of exposure. Protein profiling by SDS-PAGE and 2-dimensional gel electrophoresis (2-DE) revealed major changes in the number as well as expression of proteins. Analysis of 2-DE gel spots indicated up/down-regulation of several proteins under the stress of UV-B radiation. Thirteen differentially expressed proteins including two hypothetical proteins were identified by MALDI-TOF MS and assigned to eight functional categories. Both the hypothetical proteins (gi 779821175 and gi 503938301) were over-expressed after UV-B irradiation; gi 503938301 was characterized as a member of FMN reductase superfamily whereas gi 779821175 seems to be a structural protein as it did not show any functional domain. That the expression of certain proteins under UV-B stress is indeed up-regulated was confirmed by qRT-PCR. Transcript analysis of selected gene including genes of hypothetical proteins (cp011650 and cp002886) showed over-expression under UV-B stress as compared to untreated control cultures. Although this study deals with a limited number of proteins, identification of differentially expressed proteins reported herein may prove useful in future studies especially for assessing their significance in the protection mechanism of bacteria against UV-B radiation stress. © 2016 Kumar, Babele, Singh and Kumar.