Puja Kumari

This work conducted metabolic profiling on nine brown, one red, and two green algal species collected from different sampling sites of Kuwait’s coastal waters in the Arabian Gulf. Crude extracts of freeze-dried seaweed samples were prepared using solvents of different polarities by solvent extraction, namely, methanol and dichloromethane, and analysed by liquid chromatography-mass spectrometry for metabolite identification. The Principal Component Analysis scores scatter plot grouped the extracts of Codium papillatum, Chondria sp., Iyengaria stellata, Feldmannia indica, Padina boergesenii, Colpomenia sinuosa, Dictyota dichotoma, Sargassum aquifolium, S. asperifolium and S. ilicifolium together, suggesting their similar chemical profiles. However, S. ilicifolium var. acaraeocarpum and C. vagabunda were separated from the remainder of seaweed taxa by unique metabolite features. As expectable, species-specific differences in chemical profiles were observed in different seaweeds. Dereplication studies were employed to identify differential metabolites and to search for their previously reported bioactivities. The study led to the tentative identification of 22 metabolites using various annotation tools contained within the Global Natural Products Social Molecular Networking platform, most importantly MolNetEnhancer. The most prevalent chemical class annotations were “terpenoids” and “lipids and lipid-like molecules”. The potential modes of action of the metabolites in certain diseases were further studied using computational approaches such as molecular docking and ligand-based pharmacophore generation. This constitutes the first metabolomics study of seaweeds from the Arabian Gulf.

The objective of the study is to investigate the mediating role of social media in order to communicate economic and development value of employer brand to create positive perception towards the organization attraction. In the proposed conceptual model we were trying to establish the relationship between these three key variables. For this, 255 responses were collected from the IT sector employee working in India. In order to test the mediation effect of social media, we performed step-wise regression on SPSS 24. Findings suggested that social media and economic and development value of employer brand dimensions are predictors of organization attraction and also mediating role of social media is positive and significant. The outcome of the study suggests that organization can use economic and development value of employer brand through social media to create pool of applicants.

Many marine algae are strong accumulators of halogens. Commercial iodine production started by burning seaweeds in the 19th century. The high iodine content of certain seaweeds has potential pharmaceutical and nutritional applications. While the metabolism of iodine in brown algae is linked to oxidative metabolism, with iodide serving the function of an inorganic antioxidant protecting the cell and thallus surface against reactive oxygen species with implications for atmospheric and marine chemistry, rather little is known about the regulation and homoeostasis of other halogens in seaweeds in general and the ecological and biological role of marine algal halogenated metabolites (except for organohalogen secondary metabolites). The present review covers these areas, including the significance of seaweed-derived halogens and of halogens in general in the context of human diet and physiology. Furthermore, the understanding of interactions between halogenated compound production by algae and the environment, including anthropogenic impacts, effects on the ozone layer and global climate change, is reviewed together with the production of halogenated natural products by seaweeds and the potential of seaweeds as bioindicators for halogen radionuclides.

The fatty acid (FA) compositions of ten seaweeds representative of Chlorophyta, Rhodophyta, and Ochrophyta from Kuwait in the Arabian Gulf region were determined and are discussed in the context of their potential nutritional perspectives for seaweed valorization. All the seaweeds had higher saturated fatty acid (SFA) and lower monounsaturated (MUFA) and polyunsaturated fatty acid (PUFA) contents than those typical of tropical environments. Palmitic, myristic, stearic, oleic, linoleic, α-linolenic, and stearidonic acids were the major FAs detected. Arachidonic, eicosapentaenoic, and docosahexaenoic acids were detected in minor amounts. Conserved fatty acid patterns revealed phylogenetic relationships among phyla, classes, and orders matching the molecular phylogenies at higher taxonomic ranks. Hierarchical clustering analyses clearly segregated different seaweeds (except Codium papillatum and Iyengaria stellata) into distinct groups based on their FA signatures. All but one species (Chondria sp.) had health-beneficial n6/n3 PUFAs (0.33:1–2.94:1) and atherogenic (0.80–2.52) and thrombogenic indices (0.61–5.17). However, low PUFA/SFA contents in most of the species (except Ulva spp.) may limit their utilization in the formulation of PUFA-rich functional foods. Ulva spp. had substantially high PUFAs with PUFA/SFA > 0.4, n6/n3 (0.33–0.66) and atherogenic (0.80–1.15) and thrombogenic indices (0.49–0.72), providing substantial potential for their utilization in food and feed applications.

The red alga ‘Bangia’ sp. ESS1, a ‘Bangia’ 2 clade member, responds to heat stress via accelerated asexual reproduction and acquires thermotolerance based on heat-stress memory. However, whether these strategies are specific to ‘Bangia’ 2, especially ‘Bangia’ sp. ESS1, or whether they are employed by all ‘Bangia’ species is currently unknown. Here, we examined the heat-stress responses of ‘Bangia’ sp. ESS2, a newly identified ‘Bangia’ clade 3 member, and Bangia atropurpurea. Intrinsic thermotolerance differed among species: Whereas ‘Bangia’ sp. ESS1 survived at 30 °C for 7 days, ‘Bangia’ sp. ESS2 and B. atropurpurea did not, with B. atropurpurea showing the highest heat sensitivity. Under sublethal heat stress, the release of asexual spores was highly repressed in ‘Bangia’ sp. ESS2 and completely repressed in B. atropurpurea, whereas it was enhanced in ‘Bangia’ sp. ESS1. ‘Bangia’ sp. ESS2 failed to acquire heat-stress tolerance under sublethal heat-stress conditions, whereas the acquisition of heat tolerance by priming with sublethal high temperatures was observed in both B. atropurpurea and ‘Bangia’ sp. ESS1. Finally, unlike ‘Bangia’ sp. ESS1, neither ‘Bangia’ sp. ESS2 nor B. atropurpurea acquired heat-stress memory. These findings provide insights into the diverse heat-stress response strategies among species from different clades of ‘Bangia’.

Even though seaweeds have been considered a nutrient-rich dietary source of minerals in other parts of the world, there is little knowledge about trace element accumulation in seaweeds of the Arabian Gulf. The Arabian Gulf is of particular interest due to being an extreme environment, as it features some of the highest temperatures and salinities observed in any marine waters in the world. This study determined the minerals contents using inductively-coupled plasma-mass spectrometry (ICP-MS) in 10 of the most common seaweeds of this region (Iyengaria stellata, Padina boergesenii, Chondria sp., Feldmannia indica, Codium papillatum, Sargassum aquifolium, Ulva chaugulii, Ulva tepida and Ulva sp.) supported by morphological and molecular (DNA barcode)-based identification. The finding of U. chaugulii reported here is a new record for Kuwait. Most of the seaweeds were rich in essential minerals including Ca, Mg, Na, K, Fe and Zn and their contents were higher than those of other mineral-rich foods. Principal component analysis revealed species-specific distributions of minerals in seaweeds. U. tepida and I. stellata were found to be exceptionally rich in most of the macro- and trace elements along with low As and Se, and thus can be utilized for food and feed applications.

The green microalga Lobosphaera incisa accumulates long-chain polyunsaturated arachidonic acid sequestered in triacylglycerols under nitrogen (N)-starvation conditions. Many of L. incisa’s physiological and metabolic responses to N-starvation have been previously investigated. However, the temporal dynamics of the volatile organic compounds (VOCs) under different N availability and their role in L. incisa stress responses have yet to be elucidated. Here, we investigated the VOC profiles of L. incisa to reveal their emission patterns, and proposed their physiological roles under N-starvation. Using gas chromatography-mass spectrometry, 42 and 19 VOCs were identified in the algal biomass (AVOCs) and in the medium (MVOCs), respectively, belonging to alkanes, alkenes, benzenoids, esters, fatty alcohols, fatty aldehydes, fatty acids (FAs), FA esters, ketones, and terpenoids; most of these are the oxidative products of FAs or photosynthetic pigment degradation. The discriminant AVOCs and MVOCs produced under N-starvation were identified by principal component analyses and hierarchical clustering. A significant treatment- and time-dependent increase in volatile FAs and their oxidative products was observed in the algal biomass and medium under N-starvation as compared to N-replete controls, following a similar pattern as reactive oxygen species (ROS) production. This suggests that VOCs may be involved in ROS scavenging. Despite the increase in total VOCs, terpenoids and alkenes decreased significantly with N-starvation duration, along with chloroplast degradation. Transcriptomics data supported the VOC patterns and revealed the upregulation of genes involved in fatty aldehyde, fatty alcohol, and ketone synthesis, including lipoxygenase, thioesterase, and fatty acyl CoA reductase, along with a decrease in the expression of genes putatively implicated in alkene biosynthesis. Several VOCs were identified as potential biotechnological targets, and their putative biosynthetic pathways were proposed, which could be genetically manipulated to enhance the yields of high value products. We conclude that VOCs may play an important role in stress metabolism, ROS scavenging, and the amelioration of oxidative stress under N-starvation. Also, VOCs released in the medium may communicate the signal to neighboring cells, thus priming them to adjust their metabolic activities to adapt to N-starvation conditions, indicating that the function of VOCs as chemical signaling messengers is conserved from microalgae to higher plants.