Bio-optic characterization of Discosphaera tubifer bloom occurs in an overcrowded fishing harbour at Veraval, India.

Discosphaera tubifer, a coccolithophore has been first time reported as a bloom-forming organism from an over-crowded fishing harbour at Veraval, west coast of India. Physiochemical and optical parameters were measured following standard protocols. Average concentration of inorganic nutrients, such as NO2-N (17.26 ± 2.92 µM), NO3-N (643.80 ± 215.99 µM), PO4-P (74.10 ± 26.52 µM) and SiO3-Si (137.66 ± 25.83 µM) were recorded as very high at Veraval port as compared to other coastal stations i.e., 1.48 ± 0.66, 49.16 ± 13.73, 10.03 ± 5.31 and 96.23 ± 22.74 µM, respectively. The pH and salinity (‰) were observed to be low (7.80 ± 0.15 and 28.00 ± 4.54 ‰) as compared to coastal seawaters (8.34 ± 0.06 and 33.24 ± 2.32 ‰). Scanning electron microscopy (SEM) and spectral signature (absorbance and reflectance) study revealed that the bloom-forming organism was D. tubifer. High-performance liquid chromatography (HPLC) study detected that chlorophyllide-a represent nearly 47.53 % of total pigment composition followed by chlorophyll c2 (27.40 %) and chlorophyll c3 (14.25 %). Four prominent absorption peaks were observed within 350 to 700 nm. The first peak was very wide and ranged from 350 to 530 nm and the rest of the three peaks ranged from 550 to 590, 590 to 650 and 650 to 690 nm, respectively. In case of reflection, three peaks appeared between 550 and 590, 590 and 630 and 630 and 670 nm. Nearly 100 % reflection was observed after 720 nm. The eutrophic condition of the port water along with low salinity and low pH might be the reason for D. tubifer bloom formation. This species-specific spectral signature of the D. tubifer bloom may be helpful for developing algorithm of remote sensing data analysis.

Water pollution of Sabarmati River--a harbinger to potential disaster.

River Sabarmati is one of the biggest and major river of Gujarat that runs through two major cities of Gujarat, Gandhinagar and Ahmedabad and finally meets the Gulf of Khambhat (GoK) in the Arabian Sea. A study was conducted to evaluate the water quality of this river, as it could possibly be one of the major sources for filling up Kalpasar, the proposed man-made freshwater reservoir supposed to be the biggest one in the world. A total of nine sampling stations were established covering 163 km stretch of the river from upstream of Gandhinagar city to Vataman near Sabarmati estuary. Physicochemical (temprature, pH, salinity, chloride, total dissolved solids, turbidity, dissolved oxygen, biochemical oxygen demand, phenol, and petroleum hydrocarbons), biological (phytoplankton), and microbiological (total and selective bacterial count) analyses indicated that the river stretch from Ahmedabad-Vasana barriage to Vataman was highly polluted due to perennial waste discharges mainly from municipal drainage and industries. An implementation of sustainable management plan with proper treatment of both municipal and industrial effluents is essential to prevent further deterioration of the water quality of this river.

3D Natural Mesoporous Biosilica-Embedded Polysulfone Made Ultrafiltration Membranes for Application in Separation Technology.

Diatoms are the most abundant photosynthetic microalgae found in all aquatic habitats. In the extant study, the spent biomass (after lipid extraction) of the centric marine diatom Thalassiosira lundiana CSIRCSMCRI 001 was subjected to acid digestion for the extraction of micro composite inorganic biosilica. Then, the resulting three-dimensional mesoporous biosilica material (diatomite) was used as a filler in polysulfone (PSF) membrane preparation by phase inversion. The fabricated PSF/diatomite composite membranes were characterized by SEM-EDX, TGA, and ATR-IR, and their performances were evaluated. The number of pores and pore size were increased on the membrane surface with increased diatomite in the composite membranes as compared to the control. The diatomite composite membranes had high hydrophilicity and thermal stability, lower surface roughness, and excellent water permeability. Membranes with high % diatomite, i.e., PSF/Dia0.5, had a maximum water flux of 806.8 LMH (Liter/m2/h) at 20 psi operating pressure. High-diatomite content membranes also exhibited the highest rejection of BSA protein (98.5%) and rhodamine 6G (94.8%). Similarly, in biomedical rejection tests, the PSF/Dia0.5 membrane exhibited a maximum rejection of ampicillin (75.84%) and neomycin (85.88%) at 20 Psi pressure. In conclusion, the mesoporous inorganic biosilica material was extracted from spent biomass of diatom and successfully used in filtration techniques. The results of this study could enhance the application of natural biogenic porous silica materials in wastewater treatment for water recycling.

Isolation and characterization of exopolysaccharide secreted by a toxic dinoflagellate, Amphidinium carterae Hulburt 1957 and its probable role in harmful algal blooms (HABs).

Extracellular polymeric substances (EPS) produced by a toxic dinoflagellate Amphidinium carterae Hulburt 1957 was isolated and characterized. Molecular masses of the EPS were about 233 and 1,354 kDa. Spectral analyses by (1)H nuclear magnetic resonance and Fourier Transformed-Infrared Spectroscopy revealed the characteristic of the functional groups viz. primary amine, carboxyl, halide, and sulfate groups present in the EPS. However, five elements (C, O, Na, S, and Ca) were detected by scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDX) analysis. X-ray diffraction and differential scanning calorimetric analysis confirmed the amorphous nature of EPS, which was comprised of an average particle size of 13.969 µm (d 0.5) with 181 nm average roughness. Two monosaccharide constituents, galactose (73.13%) and glucose (26.87%) were detected by gas chromatography-mass spectroscopy analysis. Thermal gravimetric analysis revealed that degradation of EPS obtained from A. carterae takes place in three steps. The EPS produced by A. carterae was found to be beneficial for the growth of both A. carterae and Bacillus pumilus. The potential heterogeneous properties of EPS may play an important role in harmful algal bloom.

Taxonomy and okadaic acid production of a strain of Prorocentrum lima (Dinophyceae) isolated from the Bay of Bengal, North Indian Ocean.

Prorocentrum lima (CSIRCSMCRI005) was isolated from the coastal seawater of Thonithurai, Tamil Nadu, India. Morphology of the isolate was studied using light microscopy (LM) and scanning electron microscopy (SEM) while phylogenetic analyses of the internal transcribed spacer region (ITS1-5.8s-ITS2), 18S rDNA, and large subunit (LSU) rDNA were also carried out. Growth of the isolate was studied, and okadaic acid (OA) production was examined using liquid chromatography with electrospray ionization and quadrupole time of flight mass spectroscopy (LC-ESI-Q-ToF-MS). Morphological features observed including oval cell shape with a broad middle region, narrow anterior and round posterior end, large central pyrenoid with starch sheath, smooth thecal surface, and V-shaped periflagellar area consisting of eight platelets matched with the description of the type species and those reported elsewhere. The ITS, 18S, and LSU sequence phylogenetic analysis revealed that the isolate was closely related to other strains reported from the pacific. The growth rate (µ) was 0.05 div. day-1. P. lima CSIRCSMCRI005 produced okadaic acid and related esters. The production of free and total OA was 20.12 ± 4.77 and 22.30 fg cell-1, respectively. The findings of this study contribute useful information concerning the regional risk of diarrheic shellfish poisoning in the North East Indian Ocean and the global distribution and toxic potential of Prorocentrum lima. Further studies on the ecophysiology of this strain will be helpful. This manuscript reports the detailed morphological, phylogenetic, and toxicological characterization of this species from the Bay of Bengal and the North Indian Ocean as a whole.

Improved biorefinery pathways of marine diatoms using a water miscible ionic liquid and its colloidal solution: efficient lipid extraction and in situ synthesis of fluorescent carbon dots for bio-imaging applications.

In this study, a water-miscible 'classic' ionic liquid (IL), 1-ethyl-3-methylimidazoliumacetate ([EMIM][Ac]), has been used for lipid extraction from marine diatoms Thalassiosira lundiana CSIR-CSMCRI 001 by following a non-polar solvent partition method. The composition of lipid was determined using gas chromatography-mass spectrometry (GC-MS). In total, 91.4 mg g-1 (dry wt) of lipid was produced, out of which the percentage of docosahexaenoic acids (DHA), myristic acid, palmitic acid, and arachidonic acid was 19.6%, 15.1%, 11.2%, and 10.4%, respectively. The IL-inseparable residual waste solution was directly used to generate green fluorescent carbon dots (FCDs) by constructing a colloidal solution with the help of a surface-active IL, choline dioctyl sulfosuccinate ([Cho][AOT]). The stability of colloidal FCDs was examined using FTIR, FT-NMR, and Raman spectroscopy. FCDs were extracted from the colloidal solutions via the demicellization process and characterized using HR-TEM (2 to 5 nm) and PXRD techniques. The optical properties of colloidal FCDs were measured using UV-Vis and fluorescence spectroscopy and showed a wide range of emission (λ 460 nm to λ 590 nm). Such FCD stabilized colloidal solutions could be effectively used in fluorescence imaging of yeast cells, thus making the biorefinery approach more sustainable.