Department Of Botany
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Item 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, FelixThe 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.Item First report of Planomicrobium okeanokoites associated with Himantothallus grandifolius (Desmarestiales, Phaeophyta) from Southern Hemisphere(Public Library of Science, 2023-04-14T00:00:00) Chand Saini, Khem; Gupta, Kriti; Sharma, Sheetal; Gautam, Ajay K.; Shamim, Samrin; Mittal, Divya; Kundu, Pushpendu; Bast, FelixGram-positive, aerobic, motile, rod-shaped, mesophilic epiphytic bacterium Planomicrobium okeanokoites was isolated from the surface of endemic species Himantothallus grandifolius in Larsemann Hills, Eastern Antarctica. The diversity of epiphytic bacterial communities living on marine algae remains primarily unexplored; virtually no reports from Antarctic seaweeds. The present study used morpho-molecular approaches for the macroalgae and epiphytic bacterium characterization. Phylogenetic analysis was performed using mitochondrial genome encoded COX1 gene; chloroplast genome encodes rbcL; nuclear genome encoded large subunit ribosomal RNA gene (LSU rRNA) for Himantothallus grandifolius and ribosomal encoded 16S rRNA for Planomicrobium okeanokoites. Morphological and molecular data revealed that the isolate is identified as Himantothallus grandifolius, which belongs to Family Desmarestiaceae of Order Desmarestiales in Class Phaeophyceae showing 99.8% similarity to the sequences of Himantothallus grandifolius, from King George Island, Antarctica (HE866853). The isolated bacterial strain was identified on the basis of chemotaxonomic, morpho-phylogenetic, and biochemical assays. A phylogenetic study based on 16S rRNA gene sequences revealed that the epiphytic bacterial strain SLA-357 was closest related to the Planomicrobium okeanokoites showing 98.7% sequence similarity. The study revealed the first report of this species from the Southern Hemisphere to date. Also, there has been no report regarding the association between the Planomicrobium okeanokoites and Himantothallus grandifolius; however, there are some reports on this bacterium isolated from sediments, soils, and lakes from Northern Hemisphere. This study may open a gateway for further research to know about the mode of interactions and how they affect the physiology and metabolism of each other. � 2023 Saini et al.Item Concise review of green algal genus Monostroma Thuret(Springer Science and Business Media B.V., 2022-10-27T00:00:00) Kaur, Manpreet; Kala, Swarna; Parida, Aseema; Bast, FelixMonostroma (Ulotrichales, Chlorophyta) is the most intensively cultivated genus among green seaweeds, accounting for over 90% of total green algal cultivation. It is commonly found in the eulittoral zones of marine and estuarine habitats, thus contributing significantly to the ecology of the coastal ecosystem. Morphologically, the frond of Monostroma is blade-like with eponymous one-cell thickness; therefore, it is also known as �Slender sea lettuce�. Monostroma nitidum is often used for salad ingredients, boiled tsukudani, soups, etc., due to its health benefits. Monostroma kuroshiense is commercially cultivated in�East Asia�and�South America�for the edible product "hitoegusa-nori" or "hirohano-hitoegusa nori", popular�sushi�wraps. This genus remains one of the well-studied seaweed genera for ecophysiology, habitat-dependent seasonality of its growth pattern, gametangial ontogeny and phylogenetics. Moreover, rhamnan sulfate (RS), a sulfated polysaccharide, is the main component of the fiber extracted from�M. nitidum and studied for various biological activities. This review presents the taxonomy, morphology, anatomy, life history, distribution, ecology, physiology, cultivation and harvesting, chemical composition, and biotechnological applications of this genus. � 2022, The Author(s), under exclusive licence to Springer Nature B.V.Item Status, Issues, and Challenges of Biodiversity: Marine Biota(Springer Nature, 2022-09-15T00:00:00) Yadav, Digvijay Singh; Rani, Alka; Dubey, Sheetal; Bast, FelixIndia is one of the mega biodiversity countries, owing to its tropical location and warm climate. With more than 7500 km, India is blessed with a long coastline-one of the longest in the world. However, marine biodiversity remains poorly documented compared with that of terrestrial biodiversity. On top of it, the threats from climate change are imminent and have already started wreaking havoc on species diversity, for instance, ocean acidification causing coral bleaching in the atolls of the Laccadive Islands. A systematic approach to acquiring complete and exhaustive knowledge about marine biodiversity may help us understand the extent of anthropogenic damage and take appropriate actions and policies to prevent further loss. Currently, we merely know the tip of the global biodiversity iceberg; with merely 1.3 million species characterized yet, estimates suggest there might be around 9 million species of eukaryotes alone. Conserving biodiversity is crucial not only for ecosystem services but also for future generations as a possible revenue generator-the so called bequest value. This chapter reviews the status of marine biodiversity along India�s coasts, efforts on its economic utilization, and the impact of climate change. � Indian National Science Academy 2022.Item 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, FelixHigh 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.Item 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, FelixContamination 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.Item Impact of light on microalgal photosynthetic microbial fuel cells and removal of pollutants by nanoadsorbent biopolymers: Updates, challenges and innovations(Elsevier Ltd, 2021-10-20T00:00:00) Khan, Mohd Jahir; Singh, Nikhil; Mishra, Sudhanshu; Ahirwar, Ankesh; Bast, Felix; Varjani, Sunita; Schoefs, Benoit; Marchand, Justine; Rajendran, Karthik; Banu, J. Rajesh; Saratale, Ganesh Dattatraya; Saratale, Rijuta Ganesh; Vinayak, VandanaPhotosynthetic microbial fuel cells (PMFCs) with microalgae have huge potential for treating wastewater while simultaneously converting light energy into electrical energy. The efficiency of such cells directly depends on algal growth, which depends on light intensity. Higher light intensity results in increased potential as well as enhancement in generation of biomass rich in biopolymers. Such biopolymers are produced either by microbes at anode and algae at cathode or vice versa. The biopolymers recovered from these biological sources can be added in wastewater alone or in combination with nanomaterials to act as nanoadsorbents. These nanoadsorbents further increase the efficiency of PMFC by removing the pollutants like metals and dyes. In this review firstly the effect of different light intensities on the growth of microalgae, importance of diatoms in a PMFC and their impact on PMFCs efficiencies have been narrated. Secondly recovery of biopolymers from different biological sources and their role in removal of metals, dyes along with their impact on circular bioeconomy have been discussed. Thereafter bottlenecks and future perspectives in this field of research have been narrated. � 2021 Elsevier LtdItem 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, ChristianeMicroorganisms 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.Item 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, FelixArctic 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.Item DNA barcode-based phylogenetic assessment of selected mangroves from sundarbans delta and Kerala(Springer Nature, 2021-06-02T00:00:00) Rani, Alka; Jugale, Smita; Bast, FelixIndia harbors the wealthiest biodiversity of mangroves, yet the utilization of sequence-based DNA barcodes for the characterization of mangrove diversity from the Indian coastal region is needed to be explored. In the present study, we assessed DNA barcode-based phylogenetics of mangroves from Sundarbans Delta and Kerala at the ITS locus of the nuclear genome. The phylogenetic analysis was performed using Bayesian inference, which proved to resolve the evolutionary affinities effectively. Our study presents mangroves� systematic assessment with total 6 DNA sequences generated from 5 genera, and the first DNA barcode of Volkameria inermis and Avicennia marina from Payyanur Kerala, Avicennia alba and Suaeda maritima from the Sundarbans Delta was reported from ITS locus. The phylogenetic assessment confirmed that Avicennia belongs to the family Acanthaceae and placed the Volkameria inermis from Payyanur and Clerodendrum eriophyllum under the same monophyletic clade. � 2021, Indian National Science Academy.