Suaeda maritima (L.) Dumort GREEN SYNTHESIS- REDUCED NICKEL OXIDE NANOPARTICLES FOR ANTIOXIDANT AND BACTERICIDAL ACTIVITY

A unique way, green, cost-effective, and direct fabrication method is proposed for the synthesis of Nickel Oxide Nanoparticles (NPs) in an eco-environmentally way through leaf extract of Suaeda maritima (L.) Dumort. The nickel oxide nanoparticles were synthesized using Nickel (II) nitrate hexahydrate as a metal source and aqueous leaf extract of S. maritima was utilized as a green reducing agent. The formation of NPs was monitored by the change in color in the reaction mixture and the synthesized NPs were characterized using UV-visible spectrophotometer, Fourier Transform infrared (FT-IR) spectroscopy, field emission scanning electron microscope (FE SEM), X-ray diffractometer (XRD), and energy-dispersive X-ray spectroscopy (EDX). Further, the antibacterial activity of synthesized NPs was carried using the agar plate well diffusion method and antioxidant activity by DPPH free radical scavenging activity of the NPs was studied. The UV-visible absorption spectra of nanoparticles show a characteristic maximum absorption peak centered at 397 nm. The functional group analysis by FT-IR confirms the presence of various bio-active functional groups in the synthesized particles. The structural characterization confirms that the particles were Face Centred Cubic lattice structure having IR-regular in shape and rough surface with average atomic weight percentages of 76.3%. The synthesized nanoparticles were found to be potent against the growth of gram-positive (Bacillus subtilis, Staphylococcus aureus) and gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. In the DPPH assay, the IC 50 values of the synthesized NPs were found to be 28.01 μg/mL which is very close to standard ascorbic acid (22.19 μg/mL) whereas the IC 50 of the aqueous plant leaf extract was found to be 47.30 μg/m confirms that the nanoparticles having enhanced antioxidant activity. From the results of the study it can be concluded that this protocol is simple, rapid, one step, eco-friendly, non-toxic for the synthesis of nickel nanoparticles.

PHYTOREMEDIATION OF HEAVY METALS BY THE DOMINANT MANGROVE ASSOCIATE SPECIES OF INDIAN SUNDARBANS

The present study aims to investigate the phytoremediation potential of zinc (Zn), copper (Cu), and lead (Pb) by two dominant mangrove associate species, Suaeda maritima, and Salicornia brachiata, found in the high saline supralittoral zone of Indian Sundarbans in four stations of the Hooghly-Matla estuarine complex during the premonsoon season (May 2019). We found that concentrations of biologically available heavy metals (HMs) in the ambient soil and bioaccumulated HMs within the vegetative plant parts occurred as per the order: Sagar South > Bakkhali > Jharkhali > Bali Island. The order of biologically available and bioaccumulated HMs was Zn > Cu > Pb. Interestingly, the selected HMs display high organ-specificity for both species with the highest enrichment in roots, followed by stems and leaves. We propose that these halophytes could be used as agents of phytoremediation and their farming would be effective in the ecorestoration of this deltaic complex in context to conservative pollutants.

Purification and characterization of bioactive compounds extracted from Suaeda maritima leaf and its impact on pathogenicity of Pseudomonas aeruginosa in Catla catla fingerlings

Incidence of various dreadful microbial infections and the development of antibiotic resistance by infection causative microbes are the main reasons for reducing aquaculture productivity. Hence, there is an immense need for the discovery of alternative and efficient treatment for quick recovery of diseased fishes. In the present study, Suaeda maritima leaf extracts (hexane, diethyl ether, ethanol, and water) were screened for in vitro and in vivo antibacterial and antioxidant activities. Out of all the four extracts, ethanolic extract showed highest antibacterial activity against S. aureus (4.9 ± 1.3 mm), B. subtilis (1.6 ± 0.3 mm), K. pneumoniae (4.2 ± 1.8 mm), and P. aeruginosa (4.1 ± 1.2 mm). Similarly, antioxidant activity was also higher for ethanolic extract (500 µg/mL) based on DPPH radical scavenging ability (71.6 ± 1.4%) and reducing potential (149 μg/mL) assays. Further, ethanolic extract was purified consecutively via column chromatography and preparative TLC where an active fraction was selected based on highest antibacterial (10.1 ± 1.4 mm) and antioxidant properties (82.3 ± 2.8%). Active fraction was loaded onto mass spectroscopy and identified the presence of four active constituents such as 1,2,9,10-tetramethoxy-6-methyl-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinolin-3-yl) methanol; 3',7-Dimethoxy-3-hydroxyflavone; Saponin and (19R)9acetyl19hydroxy10,14dimethyl20oxopentacyclo[11.8.0.0 < 2,10 > .0 < 4,9 > .0 < 14,19 >]henicos-17-yl-acetate. Besides, in vivo studies were conducted on Catla catla fingerlings infected with P. aeruginosa under laboratory conditions. The fingerlings were segregated into 5 groups, among which group 4 and 5 were treated with crude and purified extracts. Both the extracts were efficient in treating infected fingerlings and recorded 100% survival rate which is even better than group-3 treated with a synthetic antibiotic (77%). Hence, S. maritima leaf extract can be considered as a possible alternative medicine in aquaculture.

Purification and Characterization of Bioactive Compounds Extracted from Suaeda Maritima Leaf and its Impact on Pathogenicity of Pseudomonas Aeruginosa in Catla Catla Fingerlings

Incidence of various dreadful microbial infections and the development of antibiotic resistance by infection causative microbes are the main reasons for reducing aquaculture productivity. Hence, there is an immense need for the discovery of alternative and efficient treatment for quick recovery of diseased fishes. In the present study, Suaeda maritima leaf extracts (hexane, diethyl ether, ethanol, and water) were screened for in vitro and in vivo antibacterial and antioxidant activities. Out of all the four extracts, ethanolic extract showed highest antibacterial activity against S.aureus (4.9±1.3 mm), B.subtilis (1.6±0.3 mm), K.pneumonia (4.2±1.8 mm), and P.aeruginosa (4.1±1.2 mm). Similarly, antioxidant activity was also higher for ethanolic extract (500 µg/ml) based on DPPH radical scavenging ability (71.6±1.4 %) and reducing potential (149 μg/mL) assays. Further, ethanolic extract was purified consecutively via column chromatography and preparative TLC where an active fraction was selected based on highest antibacterial (10.1±1.4 mm) and antioxidant properties (82.3±2.8 %). Active fraction was loaded onto mass spectroscopy and identified the presence of four active constituents such as 1,2,9,10-tetramethoxy-6-methyl-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinolin-3-yl) methanol; 3',7-Dimethoxy-3-hydroxyflavone; Saponin and (19R)9acetyl19hydroxy10,14dimethyl20oxopentacyclo[11.8.0.0<2,10>.0<4,9>.0<14,19>]henicos-17-yl-acetate. Besides, in vivo studies were conducted on Catla catla fingerlings infected with P. aeruginosa under laboratory conditions. The fingerlings were segregated into 5 groups, among which group 4 and 5 were treated with crude and purified extracts. Both the extracts were efficient in treating infected fingerlings and recorded 100% survival rate which is even better than group-3 treated with a synthetic antibiotic (77%). Hence, S. maritima leaf extract can be considered as a possible alternative medicine in aquaculture

Green synthesis, characterization, antioxidant, antibacterial, and photocatalytic activity of Suaeda maritima (L.) Dumort aqueous extract-mediated copper oxide nanoparticles

Background The aim of this work was to synthesize copper oxide nanoparticles (CuO NPs) utilizing heartwood aqueous extract of Suaeda maritima (L.) Dumort. The synthesis of CuO NPs using green methodology with small size and high stability paved the way to protect the environment by not involving toxic chemicals and environment-friendly methodology for pharmacological and photocatalytic applications. The aqueous areal parts extract of S. maritima (L.) Dumort was used for synthesis, characterization of CuO NPs was studied, and further its antioxidant, antibacterial, and photocatalytic activity for the removal of methylene blue was studied. Results The synthesized CuO NPs shows characteristic UV-visible absorption maximum at 282 nm. The FT-IR spectra shows peak at 3640 cm−1 attributed to hydrogen bonded O-H group of poly phenols, alcohols, and N-H of amide. Strong peak at 1122 cm−1 corresponds to C-OH stretch in phenols and alcohols. Peaks at 1467 cm−1 and 1585 cm−1 corresponds to C=C in aromatic compounds. Strong peak at 1749 cm−1 represents the C=O in aldehydes or in keto compounds. Several strong bonds identified in the range of 1088 to 1225 cm−1 representing C-O-C stretch vibrations. The synthesized particles were circular in shape with rough surface morphology and dispersed as clusters with size of 37 nm with metallic content of 73.8%. The synthesized CuO NPs were proved as potent antibacterial and antioxidant activities. The photocatalytic for the removal of methylene blue in aqueous solution was studied and results proved that the CuO NPs were effectively remove the dye up to 86.91% within less time of 75 min. Hence, the CuO NPs synthesized are high efficiency with less particle size and can be used as antioxidant, antibacterial agent, and also applicable for the removal of hazardous methylene blue dye from effluents and can contribute indirectly to clean up the environment. Conclusions The investigation reports the eco-friendly, cost-effective method for synthesizing copper oxide nanoparticles from S. maritima extract with biomedical applications.

Effect of Salinity and Nitrogen Form in Irrigation Water on Growth, Antioxidants and Fatty Acids Profiles in Halophytes Salsola australis, Suaeda maritima, and Enchylaena tomentosa for a Perspective of Biosaline Agriculture

Cultivation of salt-tolerant crops help to face to irreversible global salinization of freshwater and soils. In New-Caledonia, three halophytes are candidates for saline crops, Salsola australis R.Br., Suaeda maritima (L.) Dumort and Enchylaena tomentosa R.Br. Their success and quality depend yet on availabilities of salinity and essential nutrients in agrosystems. So, we investigated effects of three salinities, i.e., control moderate and high, and five nitrogen ratios, i.e., 100:0, 75:25, 50:50, 25:75 or 0:100 NO3−-N:NH4+-N ratio on their growth and functional value for fatty acids and antioxidants. Results show that the leaf fatty acid and antioxidant profiles of species, emphasize their good potential to become functional crop products, based on comparison with other functional plants, dietetic recommendation, or functional indices. However, their total phenolic compounds (TPC) content can be influenced by N-ratio (Suaeda maritima and Enchylaena tomentosa) and their antioxidant activity index (AAI) can be influenced by salinity (Suaeda maritima), N-ratio (Salsola australis) or both (Enchylaenatomentosa). Their quantitative and/or qualitative fatty acid profiles can also be influenced by salinity (Enchylaena tomentosa), N-ratio (Suaeda maritima), or both (Salsola australis). Regarding these variations, involving salt tolerance and nitrogen nutrition mechanisms, we recommend suitable treatments to maintain or optimize the growth and the functional quality of leaves in the three species.

Salt Tolerance in the Halophyte Suaeda maritima L. Dum.—the Effect of Oxygen Supply and Culture Medium on Growth

Suaeda maritima is an annual species that grows in salt marshes and tolerates not only salt but also flooding, although plants are smaller at lower than at higher elevations of salt marshes. We investigated whether adventitious roots play a role in tolerance to flooding and how flooding affects ion accumulation in the shoots, a determinant of growth in this species. We examined the response of plants grown in Stout and Arnon culture solution to different periods of flooding at different salinities and verified our results with plants grown in other culture solutions (Hoagland and Yoshida). We measured growth, photosynthesis and estimated stomatal frequency as well as the accumulation of Na+, Ca2+, Mg2+ and K+: plants grew and photosynthesised optimally in 200-mM Na+ (in Stout and Arnon solution), but the optimal concentration for growth increased to 450 mM when in Yoshida solution. Flooding always decreased growth, but had little effect on Na+ concentrations. Although plants produced adventitious roots, their mass decreased rather than increased with flooding. The decrease in production of adventitious roots under flooded conditions suggested that they were not important in the tolerance of this species to submergence—an unusual response compared with the general response of flooding-tolerant plants.