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Coastal waters are dynamic because of anthropogenic activities that contribute nutrients and contaminants. These changes have the potential to alter patterns of primary production and thus pelagic food webs. Here, we investigated the spatial variation of the phytoplankton community and its response to changing environmental variables at 84 stations along the five coastal districts of Tamil Nadu (TN). During the present study, 85 phytoplankton species were recorded, such as diatoms (64), dinoflagellates (18), silicoflagellates (1), and Cyanophyceae (2). The maximum phytoplankton abundance was recorded on the Thanjavur coast and gradually decreased towards the south coast of Tamil Nadu. Among the phytoplankton community, 50% was dominated by pennate diatoms, attributed to higher NO3− concentrations in the coastal waters due to agricultural discharge. Cluster analysis revealed that Ramanathapuram and Tirunelveli formed a closed cluster, whereas Thanjavur and Pudukottai formed a separate closed cluster associated with higher nutrient and metal concentrations, highlighting the difference in physicochemical parameters between the northern and southern districts of the TN coast. Relatively high nutrient concentrations in the coastal waters of northern districts are of greater concern, which could impact the coastal ecosystem. Coastal eutrophication is becoming a widespread phenomenon, causing disruption in the food chain and ecosystem balances and hence requiring regular monitoring and management.

The present study investigated the phytoplankton assemblage and diversity with physicochemical parameters of Diu coastal waters in different seasons during 2018–19. During the study period, 61 phytoplankton species comprising diatoms (50 sp.), dinoflagellates (8 sp.), and cyanophyceae (3 sp.) were recorded. Diatom was found to be a major community and contributed 79 to 99% of total phytoplankton abundance. Reduction in dinoflagellate and dominance of pennate-diatoms were observed during the monsoon. Chlorophyll-a concentration also showed a similar trend and decreased during the monsoon. However, the phytoplankton abundance was low particularly during the monsoon which might be due to the elevated total suspended solids (TSS) load. Canonical correspondence analysis revealed that diatoms were able to survive in high TSS with the support of high nutrients; while dinoflagellates were limited due to those conditions. Overall, the reduction in phytoplankton abundance, diversity, and biomass was recorded due to the elevated TSS input along the coastal waters of Diu.

Coastal regions of India are prone to sea level rise, cyclones, storm surges, and human-induced activities, resulting in flood, erosion, and inundation, and some of these impacts could be attributed to climate change. Mangroves play a very protective role against some of these coastal hazards. The primary aim of the study was to estimate wave energy attenuation by mangrove vegetation using modeling, and to validate the model results with measurements conducted off Mumbai coast, where a mangrove forest is present. Wave measurements were carried out from 5−8 August 2015 at three locations in a transect normal to the coast using surface-mounted pressure-level sensors in spring tide conditions. The measured data presented wave height attenuation of the order of 52%. Model set-up and sensitivity analyses were conducted to understand the model performance with respect to vegetation parameters. It was observed that wave attenuation increases with an increase in drag coefficient, vegetation density, and stem diameter. For a typical set-up in the Mumbai coastal region having a vegetation density of 0.175 per m2, stem diameter of 0.3 m, and drag coefficient varying from 0.4 to 1.5, the model reproduced attenuation ranging from 49% to 55%, which matches reasonably well with the measured data. Spectral analysis performed for the cases with and without vegetation very clearly portrays energy dissipation in the vegetation area. This study also highlights the importance of climate change and mangrove vegetation.

Staphylococcus gallinarum FCW1 was isolated from naturally fermented coconut-water and identified by biochemical and molecular methods. Probiotic characterization and safety assessment were conducted through a series of in vitro tests. A high survival rate was observed when the strain was tested for resistance to bile, lysozyme, simulated gastric and intestinal fluid, phenol, and different temperature and salt concentrations. The strain showed antagonism against some pathogens, was susceptible to all antibiotics tested except penicillin, and showed no hemolytic and DNase activity. Hydrophobicity, autoaggregation, biofilm formation, and antioxidation tests indicated that the strain possessed a high adhesive and antioxidant ability. Enzymatic activity was used to evaluate the metabolic capacities of the strain. In-vivo experiment on zebrafish was performed to check its safety status. The whole-genome sequencing indicated that the genome contained 2,880,305 bp with a GC content of 33.23%. The genome annotation confirmed the presence of probiotic-associated genes and genes for oxalate degradation, sulfate reduction, acetate metabolism, and ammonium transport in the FCW1 strain, adding to the theory that this strain may be helpful in treating kidney stones. This study revealed that the strain FCW1 might be an excellent potential probiotic in developing fermented coconut beverages and treating and preventing kidney stone disease., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Antimicrobial peptide crustin was isolated and purified from Penaeus semisulcatus using Sephadox G-100 column gel filtration chromatography. P. semisulcatus crustins was observed as a single band with 14 kDa of molecular weight on SDS-PAGE and the retention time of 46 min in RP-HPLC. Circular dichroism spectra of P. semisulcatus crustin showed alpha helices in its secondary structure followed by random coils. Crystalline nature and functional groups arrangement were investigated by X-Ray Diffraction (XRD) and Fourier Transform Infra-Red spectroscopy (FTIR). P. semisulcatus crustin showed the effective antibacterial activity against Gram positive strains B. thuringienisis (4 μg/ml) and B. pumilis (6 μg/ml) when compare to Gram negative strains. Biofilm Inhibitory Concentration (BIC) were determined for these strains and percentage of biofilm inhibition was confirmed and visualized through in sit microscopic analysis. Hence, we reported the effect of crustin on biofilm inhibition and eradication at low concentrations by using crystal violet staining and confocal microscopic observations. In addition, haemolytic activity of this purified crustin also analysed using human RBCs. The results of this study, suggests that this bio peptide crustin is a potential and promising therapeutic agent to treat drug resistant bacteria and biofilm-related infections., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The interaction of surfactant-cobalt(III) complexes [Co(bpy)(dien)TA](ClO4)3 · 3H2O (1) and [Co(dien)(phen)TA](ClO4)3 · 4H2O (2), where bpy = 2,2'-bipyridine, dien = diethylenetriamine, phen = 1,10-phenanthroline and TA = tetradecylamine with human serum albumin (HSA) under physiological conditions was analyzed using steady state, synchronous, 3D fluorescence, UV/visabsorption and circular dichroism spectroscopic techniques. The results show that these complexes cause the fluorescence quenching of HSA through a static mechanism. The binding constant (Kb ) and number of binding-sites (n) were obtained at different temperatures. The corresponding thermodynamic parameters (∆G°, ∆H° and ∆S°) and Ea were also obtained. According to Förster's non-radiation energy transfer theory, the binding distance (r) between the complexes and HSA were calculated. The results of synchronous and 3D fluorescence spectroscopy indicate that the binding process has changed considerably the polarity around the fluorophores, along with changes in the conformation of the protein. The antimicrobial and anticancer activities of the complexes were tested and the results show that the complexes have good activities against pathogenic microorganisms and cancer cells., (Copyright © 2015 John Wiley & Sons, Ltd.)

The polymer-cobalt(III) complexes, [Co(bpy)(dien)BPEI]Cl3 · 4H2O (bpy = 2,2'-bipyridine, dien = diethylentriamine, BPEI = branched polyethyleneimine) were synthesized and characterized. The interaction of these complexes with human serum albumin (HSA) and bovine serum albumin (BSA) was investigated under physiological conditions using various physico-chemical techniques. The results reveal that the fluorescence quenching of serum albumins by polymer-cobalt(III) complexes took place through static quenching. The binding of these complexes changed the molecular conformation of the protein considerably. The polymer-cobalt(III) complex with x = 0.365 shows antimicrobial activity against several human pathogens. This complex also induces cytotoxicity against MCF-7 through apoptotic induction. However, further studies are needed to decipher the molecular mode of action of polymer-cobalt(III) complex and for its possible utilization in anticancer therapy., (Copyright © 2015 John Wiley & Sons, Ltd.)

The comparative binding effect of single and double aliphatic chain containing surfactant-cobalt(III) complexes cis-[Co(bpy)2(DA)2](ClO4)3·2H2O (1), cis-[Co(bpy)2(DA)Cl](ClO4)2·2H2O (2), cis-[Co(phen)2(CA)2](ClO4)3·2H2O (3), and cis-[Co(phen)2(CA)Cl](ClO4)2·2H2O (4) with bovine serum albumin (BSA) under physiological condition was analyzed by steady state, time resolved fluorescence, synchronous, three-dimensional fluorescence, UV-Visible absorption and circular dichroism spectroscopic techniques. The results show that these complexes cause the fluorescence quenching of BSA through a static mechanism. The binding constants (Kb) and the number of binding sites were calculated and binding constant values are found in the range of 10(4)-10(5) M(-1). The results indicate that compared to single chain complex, double chain surfactant-cobalt(III) complex interacts strongly with BSA. Also the sign of thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicate that all the complexes interact with BSA through hydrophobic force. The binding distance (r) between complexes and BSA was calculated using Förster non-radiation energy transfer theory and found to be less than 7 nm. The results of synchronous, three dimensional fluorescence and circular dichroism spectroscopic methods indicate that the double chain surfactant-cobalt(III) complexes changed the conformation of the protein considerably than the respective single chain surfactant-cobalt(III) complexes. Antimicrobial studies of the complexes showed good activities against pathogenic microorganisms., (Copyright © 2013 Elsevier B.V. All rights reserved.)