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Browsing by Author "Saini, Khem Chand"

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Abiotic stress in algae: response, signaling and transgenic approaches
(Springer Science and Business Media B.V., 2022-05-02T00:00:00) Kaur, Manpreet; Saini, Khem Chand; Ojah, Hiramoni; Sahoo, Rajalakshmi; Gupta, Kriti; Kumar, Adesh; Bast, Felix
High salinity, nutrient deficiency, heavy metals, desiccation, temperature fluctuations, and ultraviolet radiations are major abiotic stress factors considered inhospitable to algal growth and development in natural and artificial environments. All these stressful conditions cause effects on algal physiology and thus biochemical functioning. For instance, long-term exposure to hyper/hypo salinity conditions inhibits cell differentiation and reduces growth. Photosynthesis is completely blocked in algae's dehydrated state, resulting in photoinhibition or photodamage. The limitation of nutrients in aquatic environments inhibits primary production via regulating phytoplankton community development and structure. Hence, in response to these stressful conditions, algae develop plenty of cellular, physiological, and morphological defences to survive and thrive. The conserved and generalized defence responses in algae include the production of secondary metabolites, desaturation of membrane lipids, activation of reactive species scavengers, and accumulation of compatible solutes. Moreover, a well-coordinated and timely response to such stresses involves signal perception and transduction mainly via phytohormones that could sustain algae growth under abiotic stress conditions. In addition, the combination of abiotic stresses and plant hormones could further elevate the biosynthesis of metabolites and enhance the ability of algae to tolerate abiotic stresses. This review aims to present different kinds of stressful conditions confronted by algae and their physiological and biochemical responses, the role of phytohormones in combatting these conditions, and, last, the future transgenic approaches for improving abiotic stress tolerance in algae. � 2022, The Author(s), under exclusive licence to Springer Nature B.V.
Abiotic stress in algae: response, signaling and transgenic approaches
(Springer Science and Business Media B.V., 2022-05-02T00:00:00) Kaur, Manpreet; Saini, Khem Chand; Ojah, Hiramoni; Sahoo, Rajalakshmi; Gupta, Kriti; Kumar, Adesh; Bast, Felix
High salinity, nutrient deficiency, heavy metals, desiccation, temperature fluctuations, and ultraviolet radiations are major abiotic stress factors considered inhospitable to algal growth and development in natural and artificial environments. All these stressful conditions cause effects on algal physiology and thus biochemical functioning. For instance, long-term exposure to hyper/hypo salinity conditions inhibits cell differentiation and reduces growth. Photosynthesis is completely blocked in algae's dehydrated state, resulting in photoinhibition or photodamage. The limitation of nutrients in aquatic environments inhibits primary production via regulating phytoplankton community development and structure. Hence, in response to these stressful conditions, algae develop plenty of cellular, physiological, and morphological defences to survive and thrive. The conserved and generalized defence responses in algae include the production of secondary metabolites, desaturation of membrane lipids, activation of reactive species scavengers, and accumulation of compatible solutes. Moreover, a well-coordinated and timely response to such stresses involves signal perception and transduction mainly via phytohormones that could sustain algae growth under abiotic stress conditions. In addition, the combination of abiotic stresses and plant hormones could further elevate the biosynthesis of metabolites and enhance the ability of algae to tolerate abiotic stresses. This review aims to present different kinds of stressful conditions confronted by algae and their physiological and biochemical responses, the role of phytohormones in combatting these conditions, and, last, the future transgenic approaches for improving abiotic stress tolerance in algae. � 2022, The Author(s), under exclusive licence to Springer Nature B.V.
Arctic biodiversity amidst looming climate apocalypse: Current status and way forward
(Elsevier, 2021-08-27T00:00:00) Rani, Alka; Gupta, Kriti; Saini, Khem Chand; Narwal, Sahil; Bast, Felix
Arctic region is at the forefront of climate crisis; this is where the planet is warming maximally and the effects of climate change are most obvious. In this review, we introduce the topic in broader perspective by discussing first on why Arctic biodiversity matters, and scientific evidences for a changing Arctic biodiversity due to climate change. The Arctic then dwells into the current status of Arctic biodiversity covering species diversity and its conservation status with an emphasis on species important for bioprospecting. Subsequently, threats to Arctic biodiversity will be reviewed including climate change, shipping, oil exploration, overfishing, and overharvesting. This essay would then further deliberate why Arctic matters to India in particular. Himadri-Indian research station at Svalbard, Norway-will be briefed followed by an overview of Svalbard Global Seed Vault and why signing a pact with this international facility would benefit the country. The essay concludes with final thoughts and way forward including strategies to minimize Arctic biodiversity loss, UN SDGs (Ssustainable Ddevelopment Ggoals), and climate action. � 2021 Elsevier Inc. All rights reserved.
Arctic biodiversity amidst looming climate apocalypse: Current status and way forward
(Elsevier, 2021-08-27T00:00:00) Rani, Alka; Gupta, Kriti; Saini, Khem Chand; Narwal, Sahil; Bast, Felix
Arctic region is at the forefront of climate crisis; this is where the planet is warming maximally and the effects of climate change are most obvious. In this review, we introduce the topic in broader perspective by discussing first on why Arctic biodiversity matters, and scientific evidences for a changing Arctic biodiversity due to climate change. The Arctic then dwells into the current status of Arctic biodiversity covering species diversity and its conservation status with an emphasis on species important for bioprospecting. Subsequently, threats to Arctic biodiversity will be reviewed including climate change, shipping, oil exploration, overfishing, and overharvesting. This essay would then further deliberate why Arctic matters to India in particular. Himadri-Indian research station at Svalbard, Norway-will be briefed followed by an overview of Svalbard Global Seed Vault and why signing a pact with this international facility would benefit the country. The essay concludes with final thoughts and way forward including strategies to minimize Arctic biodiversity loss, UN SDGs (Ssustainable Ddevelopment Ggoals), and climate action. � 2021 Elsevier Inc. All rights reserved.
Environmental Friendly Technologies for Remediation of Toxic Heavy Metals: Pragmatic Approaches for Environmental Management
(Springer International Publishing, 2022-05-06T00:00:00) Sharma, Ritika; Saini, Khem Chand; Rajput, Sneh; Kumar, Mohit; Mehariya, Sanjeet; Karthikeyan, Obulisamy Parthiba; Bast, Felix
Contamination of different environmental matrices (air, soil, and water) by toxic heavy metals is a widespread problem that disturbs the environment as an outcome of many anthropocentric practices. Heavy metals exceeding the permissible limits exert deleterious impacts on human beings, causing life-threatening health manifestations and detrimental effects on the environment. This has alarmed the dire need to explore various modern remediation techniques that can be utilized to lower excessive concentrations. Owing to their high-cost effectiveness, unsatisfactory output, environmentally unfriendly, complicated procedure, and high operational costs, these technologies failed to find any practical utility in remediation. On the other hand, plants and associated microorganisms are receiving more consideration as a means of remediating or degrading environmental pollutants. This chapter provides us insights into the various environmental friendly techniques that will improve our environment�s quality. Among which, phytoremediation is considered an effective technique which is known for its esthetic benefits and endless applicability. Furthermore, metal-resistant bacteria (plant growth-promoting rhizobacteria) are also reported to play a pivotal role in the phytoremediation and solubilization of minerals. Thus, this chapter critically reviews the phytoremediation technology and the efficient exploitation of microbes to alleviate the environmental burden of toxic heavy metals. � The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.
Environmental Friendly Technologies for Remediation of Toxic Heavy Metals: Pragmatic Approaches for Environmental Management
(Springer International Publishing, 2022-05-06T00:00:00) Sharma, Ritika; Saini, Khem Chand; Rajput, Sneh; Kumar, Mohit; Mehariya, Sanjeet; Karthikeyan, Obulisamy Parthiba; Bast, Felix
Contamination of different environmental matrices (air, soil, and water) by toxic heavy metals is a widespread problem that disturbs the environment as an outcome of many anthropocentric practices. Heavy metals exceeding the permissible limits exert deleterious impacts on human beings, causing life-threatening health manifestations and detrimental effects on the environment. This has alarmed the dire need to explore various modern remediation techniques that can be utilized to lower excessive concentrations. Owing to their high-cost effectiveness, unsatisfactory output, environmentally unfriendly, complicated procedure, and high operational costs, these technologies failed to find any practical utility in remediation. On the other hand, plants and associated microorganisms are receiving more consideration as a means of remediating or degrading environmental pollutants. This chapter provides us insights into the various environmental friendly techniques that will improve our environment�s quality. Among which, phytoremediation is considered an effective technique which is known for its esthetic benefits and endless applicability. Furthermore, metal-resistant bacteria (plant growth-promoting rhizobacteria) are also reported to play a pivotal role in the phytoremediation and solubilization of minerals. Thus, this chapter critically reviews the phytoremediation technology and the efficient exploitation of microbes to alleviate the environmental burden of toxic heavy metals. � The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.
INFLUENCE OF INSULIN AND METFORMIN ON PROSTATE CANCER
(Nova Science Publishers, 2017) Singh, Pushpendra; Bast, Felix; Kumar, Shashank; Saini, Khem Chand
Dietary habit and hormonal factor play a significant role in prostate cancer deregulation in addition to genetic and environmental factor. Nonandrogenic growth factor like insulin and insulin growth factor are influences the prostate cancer initiation and progression. Insulin and Insulin-like growth factor regulate various metabolic pathways, cell growth, cellular proliferation and apoptosis. Various epidemiological results point out that insulin not only increased the risk of cardiovascular, macrovascular, and microvascular complications but also at significantly increase the risk of various cancers. The use of metformin, the usually approved drug for type 2 diabetes, was continually linked with the decreased risk of the incidence of a variety of cancers. More than 60 clinical trials of metformin being tested as a treatment for various types of cancer, including breast, colon, prostate, endometrial, and pancreatic cancer. The ability of metformin to lower circulating insulin may be predominantly imperative for the treatment of cancers. Moreover, metformin inhibiting mammalian target of rapamycin promoted cell growth signaling. In this chapter, the confirmation behind a role for metformin in cancer therapy and its prospective molecular mechanisms of action are discussed.
Microorganisms: A potential source of bioactive molecules for antioxidant applications
(MDPI AG, 2021-02-22T00:00:00) Rani, Alka; Saini, Khem Chand; Bast, Felix; Mehariya, Sanjeet; Bhatia, Shashi Kant; Lavecchia, Roberto; Zuorro, Antonio
Oxidative stress originates from an elevated intracellular level of free oxygen radicals that cause lipid peroxidation, protein denaturation, DNA hydroxylation, and apoptosis, ultimately impairing cell viability. Antioxidants scavenge free radicals and reduce oxidative stress, which further helps to prevent cellular damage. Medicinal plants, fruits, and spices are the primary sources of antioxidants from time immemorial. In contrast to plants, microorganisms can be used as a source of antioxidants with the advantage of fast growth under controlled conditions. Further, microbe-based antioxidants are nontoxic, noncarcinogenic, and biodegradable as compared to synthetic antioxidants. The present review aims to summarize the current state of the research on the antioxidant activity of microorganisms including actinomycetes, bacteria, fungi, protozoa, microalgae, and yeast, which produce a variety of antioxidant compounds, i.e., carotenoids, polyphenols, vitamins, and sterol, etc. Special emphasis is given to the mechanisms and signaling pathways followed by antioxidants to scavenge Reactive Oxygen Species (ROS), especially for those antioxidant compounds that have been scarcely investigated so far. � 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Microorganisms: A potential source of bioactive molecules for antioxidant applications
(MDPI AG, 2021-02-22T00:00:00) Rani, Alka; Saini, Khem Chand; Bast, Felix; Mehariya, Sanjeet; Bhatia, Shashi Kant; Lavecchia, Roberto; Zuorro, Antonio
Oxidative stress originates from an elevated intracellular level of free oxygen radicals that cause lipid peroxidation, protein denaturation, DNA hydroxylation, and apoptosis, ultimately impairing cell viability. Antioxidants scavenge free radicals and reduce oxidative stress, which further helps to prevent cellular damage. Medicinal plants, fruits, and spices are the primary sources of antioxidants from time immemorial. In contrast to plants, microorganisms can be used as a source of antioxidants with the advantage of fast growth under controlled conditions. Further, microbe-based antioxidants are nontoxic, noncarcinogenic, and biodegradable as compared to synthetic antioxidants. The present review aims to summarize the current state of the research on the antioxidant activity of microorganisms including actinomycetes, bacteria, fungi, protozoa, microalgae, and yeast, which produce a variety of antioxidant compounds, i.e., carotenoids, polyphenols, vitamins, and sterol, etc. Special emphasis is given to the mechanisms and signaling pathways followed by antioxidants to scavenge Reactive Oxygen Species (ROS), especially for those antioxidant compounds that have been scarcely investigated so far. � 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Morpho-molecular characterization of rock-inhabiting lichen Dermatocarpon miniatum (Verrucariaceae, Ascomycota) and its symbiont in Indian Himalayas
(Springer, 2021-03-24T00:00:00) Saini, Khem Chand; Bast, Felix; Nayaka, Sanjeeva; Gautam, Ajay Kumar
The genus Dermatocarpon (Verrucariaceae) is a rock-inhabiting lichen, mostly grows along the edges of lakes, rivers, streams, and watercourses. Dermatocarpon species are widely distributed from the tropics to the polar regions. In present study, D. miniatum samples were collected from the Indian Himalayas; the mycobiont and their photobionts are identified using morphological and molecular methods. The ITS rDNA markers was amplified for the DNA extracted from cultured photobiont isolates and mycobiont. The light and confocal laser scanning microscope were used for morphological evaluation of the photobionts. The nuclear ITS rDNA gene of the mycobionts and photobionts were sequenced to confirm identity. The phylogenetic trees of mycobionts and photobionts were constructed using the Maximum likelihood method that revealed an evolutionary affinity of lichen D. miniatum and photobiont Diplosphaera chodatii with similar taxa. The D. chodatii (Trebouxiophyceae) was associated with all samples of D. miniatum. This study concludes that Diplosphaera chodatii is the primary photobiont associated with D. miniatum. To the best of our knowledge this is the first study of diversity for the photobiont associated with D. miniatum from India. � 2021, Archana Sharma Foundation of Calcutta.
Morpho-molecular characterization of rock-inhabiting lichen Dermatocarpon miniatum (Verrucariaceae, Ascomycota) and its symbiont in Indian Himalayas
(Springer, 2021-03-24T00:00:00) Saini, Khem Chand; Bast, Felix; Nayaka, Sanjeeva; Gautam, Ajay Kumar
The genus Dermatocarpon (Verrucariaceae) is a rock-inhabiting lichen, mostly grows along the edges of lakes, rivers, streams, and watercourses. Dermatocarpon species are widely distributed from the tropics to the polar regions. In present study, D. miniatum samples were collected from the Indian Himalayas; the mycobiont and their photobionts are identified using morphological and molecular methods. The ITS rDNA markers was amplified for the DNA extracted from cultured photobiont isolates and mycobiont. The light and confocal laser scanning microscope were used for morphological evaluation of the photobionts. The nuclear ITS rDNA gene of the mycobionts and photobionts were sequenced to confirm identity. The phylogenetic trees of mycobionts and photobionts were constructed using the Maximum likelihood method that revealed an evolutionary affinity of lichen D. miniatum and photobiont Diplosphaera chodatii with similar taxa. The D. chodatii (Trebouxiophyceae) was associated with all samples of D. miniatum. This study concludes that Diplosphaera chodatii is the primary photobiont associated with D. miniatum. To the best of our knowledge this is the first study of diversity for the photobiont associated with D. miniatum from India. � 2021, Archana Sharma Foundation of Calcutta.
Overview of extraction of astaxanthin from Haematococcus pluvialis using CO2 supercritical fluid extraction technology vis-a-vis quality demands
(Elsevier, 2021-04-19T00:00:00) Saini, Khem Chand; Yadav, Digvijay Singh; Mehariya, Sanjeet; Rathore, Parikshita; Kumar, Bikash; Marino, Tiziana; Leone, Gian Paolo; Verma, Pradeep; Musmarra, Dino; Molino, Antonio
Microalgae biomass have been used as a source of nutrient-rich food, feed, and health-promoting compounds. Among the several commercially available microalgae, Haematococcus pluvialis is the most abundant source of natural astaxanthin (3, 3'-dihydroxy-?, ?-carotene-4, 4'-dione), which is considered as �super antioxidant.� Therefore natural astaxanthin produced by H. pluvialis has a higher antioxidant capacity than the synthetic sources, which reduces oxidative stress and free radicals and helps the human body to maintain a healthy state. However, H. pluvialis contains astaxanthin inside the cells, which need to be extracted using nontoxic extraction technologies for different application. Among the different available extraction technologies, supercritical fluid extraction (SFE) is a modern technology with increasing applications in pharmaceutical and nutraceutical sector. The most frequently employed supercritical solvent in food and natural product processing is carbon dioxide (CO2) due to its low critical temperature and pressure while considered as nontoxic extraction solvent. Therefore, nowadays, supercritical carbon dioxide (SC-CO2) is considered as a new substitute for complete extraction of natural compounds from different matrices. However, the extraction efficiency and purity of astaxanthin in the extract are influenced by different operative conditions such as the extraction pressure, temperature, time, and use of cosolvent. Hence the optimum operative condition of SC-CO2 extraction could enhance the extraction yields of astaxanthin and of its purity the extract. Therefore present chapter summarizes the effects of several extraction parameters on SC-CO2 extraction of astaxanthin from H. pluvialis, which could serve as benchmark for future development of SC-CO2 extraction technology and its commercial implementation in pharmaceutical and nutraceutical sector. � 2021 Elsevier Inc.
A review on microbial products and their perspective application as antimicrobial agents
(MDPI, 2021-12-13T00:00:00) Rani, Alka; Saini, Khem Chand; Bast, Felix; Varjani, Sunita; Mehariya, Sanjeet; Bhatia, Shashi Kant; Sharma, Neeta; Funk, Christiane
Microorganisms including actinomycetes, archaea, bacteria, fungi, yeast, and microalgae are an auspicious source of vital bioactive compounds. In this review, the existing research regard-ing antimicrobial molecules from microorganisms is summarized. The potential antimicrobial compounds from actinomycetes, particularly Streptomyces spp.; archaea; fungi including endophytic, filamentous, and marine-derived fungi, mushroom; and microalgae are briefly described. Further-more, this review briefly summarizes bacteriocins, halocins, sulfolobicin, etc., that target multiple-drug resistant pathogens and considers next-generation antibiotics. This review highlights the pos-sibility of using microorganisms as an antimicrobial resource for biotechnological, nutraceutical, and pharmaceutical applications. However, more investigations are required to isolate, separate, purify, and characterize these bioactive compounds and transfer these primary drugs into clinically approved antibiotics. � 2021 by the authors. Li-censee MDPI, Basel, Switzerland.
A review on microbial products and their perspective application as antimicrobial agents
(MDPI, 2021-12-13T00:00:00) Rani, Alka; Saini, Khem Chand; Bast, Felix; Varjani, Sunita; Mehariya, Sanjeet; Bhatia, Shashi Kant; Sharma, Neeta; Funk, Christiane
Microorganisms including actinomycetes, archaea, bacteria, fungi, yeast, and microalgae are an auspicious source of vital bioactive compounds. In this review, the existing research regard-ing antimicrobial molecules from microorganisms is summarized. The potential antimicrobial compounds from actinomycetes, particularly Streptomyces spp.; archaea; fungi including endophytic, filamentous, and marine-derived fungi, mushroom; and microalgae are briefly described. Further-more, this review briefly summarizes bacteriocins, halocins, sulfolobicin, etc., that target multiple-drug resistant pathogens and considers next-generation antibiotics. This review highlights the pos-sibility of using microorganisms as an antimicrobial resource for biotechnological, nutraceutical, and pharmaceutical applications. However, more investigations are required to isolate, separate, purify, and characterize these bioactive compounds and transfer these primary drugs into clinically approved antibiotics. � 2021 by the authors. Li-censee MDPI, Basel, Switzerland.
Seaweed-associated epiphytic bacteria: Diversity, ecological and economic implications
(Elsevier B.V., 2023-07-18T00:00:00) Kaur, Manpreet; Saini, Khem Chand; Mallick, Ashrumochan; Bast, Felix
The microbial communities associated with seaweeds remain underexplored, despite their enormous biodiversity and the fact that they differ significantly from their free-living marinecounterpart. Studying the epiphytic bacterial microbiota, directly or indirectly, plays a vital role in normal algal morphological development, metabolism, growth and defence against fouling organisms. Furthermore, as these bacteria interact with algae in multifaceted ways, they constitute a fascinating source of new bioactive compounds with antimicrobials, antibiotic potential and produce algal-specific polysaccharidases with biotechnological applications. Microscopy, accompanied by bacterial culture and molecular biology, has made it feasible to establish and identify the phylogenetic origin of various algae-associated bacterial communities. Thus, this review first highlights the immense diversity of the epiphytic bacteria associated with algae, predominantly from the phyla Proteobacteria, Bacteroidetes, and Firmicutes. We further describe the factors affecting the composition and abundance of the epiphytic bacteria and their ecological role. We end with the bioprospecting value of this interaction, such as the production of hydrolytic enzymes and specific bioactive compounds. However, further investigation of the epiphytic bacterial communities present in different macroalgae using new technologies is still needed, mainly to evaluate the production of various metabolites with biotechnologicalapplications. � 2023 Elsevier B.V.
Seaweed-associated epiphytic bacteria: Diversity, ecological and economic implications
(Elsevier B.V., 2023-07-18T00:00:00) Kaur, Manpreet; Saini, Khem Chand; Mallick, Ashrumochan; Bast, Felix
The microbial communities associated with seaweeds remain underexplored, despite their enormous biodiversity and the fact that they differ significantly from their free-living marinecounterpart. Studying the epiphytic bacterial microbiota, directly or indirectly, plays a vital role in normal algal morphological development, metabolism, growth and defence against fouling organisms. Furthermore, as these bacteria interact with algae in multifaceted ways, they constitute a fascinating source of new bioactive compounds with antimicrobials, antibiotic potential and produce algal-specific polysaccharidases with biotechnological applications. Microscopy, accompanied by bacterial culture and molecular biology, has made it feasible to establish and identify the phylogenetic origin of various algae-associated bacterial communities. Thus, this review first highlights the immense diversity of the epiphytic bacteria associated with algae, predominantly from the phyla Proteobacteria, Bacteroidetes, and Firmicutes. We further describe the factors affecting the composition and abundance of the epiphytic bacteria and their ecological role. We end with the bioprospecting value of this interaction, such as the production of hydrolytic enzymes and specific bioactive compounds. However, further investigation of the epiphytic bacterial communities present in different macroalgae using new technologies is still needed, mainly to evaluate the production of various metabolites with biotechnologicalapplications. � 2023 Elsevier B.V.

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