Novel vanadium-binding proteins (Vanabins) identified in cDNA libraries and the genome of the ascidian Ciona intestinalis

Ascidians, especially those belonging to the suborder Phlebobranchia, can accumulate high levels of vanadium. Vanadium-binding proteins (vanabins) were first isolated from a vanadium-accumulating ascidian, Ascidia sydneiensis samea, and then the vanabins were cloned, their expression was studied, and metal-binding assays were conducted. In order to unravel the mechanism of vanadium accumulation, we searched for vanabin-like genes in other animals, including other ascidians. A database search revealed five groups of cDNAs that encoded vanabin-like proteins in another ascidian, Ciona intestinalis. The genes encoding C. intestinalis vanabins, CiVanabin1 to CiVanabin5, were clustered in an 8.4-kb genomic region. The direction of transcription of each gene was identical and each gene had a single intron. All the C. intestinalis vanabins were cysteine rich, and the repetitive pattern of cysteines closely resembled that of A. sydneiensis samea vanabins. Using immobilized metal ion affinity chromatography, we found that a recombinant protein of at least one of the C. intestinalis vanabins (CiVanabin5) bound to vanadium(IV) ions

Suaeda maritima-based herbal coils and green nanoparticles as potential biopesticides against the dengue vector Aedes aegypti and the tobacco cutworm Spodoptera litura

The overuse of synthetic pesticides to control insect pests leads to physiological resistance and adverse environmental effects, in addition to high operational cost. Insecticides of botanical origin have been reported as useful for control of agricultural and public health insect pests. This research proposed a novel method of mangrove-mediated synthesis of insecticidal silver nanoparticles (AgNP) using Suaeda maritima, acting as a reducing and stabilizing agent. AgNP were characterized by UV–vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analysis. S. maritima aqueous extract and mangrove-synthesized AgNP showed larvicidal and pupicidal toxicity against the dengue vector Aedes aegypti and the tobacco cutworm Spodoptera litura. In particular, LC50 of AgNP ranged from 8.668 (larva I) to 17.975 ppm (pupa) for A. aegypti, and from 20.937 (larva I) to 46.896 ppm (pupa) for S. litura. In the field, the application of S. maritima extract and AgNP (10 × LC50) led to 100% mosquito larval reduction after 72 h. Smoke toxicity experiments conducted on A. aegypti adults showed that S. maritima leaf-, stem- and root-based coils evoked mortality rates comparable or higher if compared to permethrin-based positive control (62%, 52%, 42%, and 50.2 respectively). In ovicidal experiments, egg hatchability was reduced by 100% after treatment with 20 ppm of AgNP and 250 ppm of S. maritima extract. Furthermore, low doses of the AgNP inhibited the growth of Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi. Overall, our results highlighted the potential of S. maritima-based herbal coils and green nanoparticles as biopesticides in the fight against the dengue vector A. aegypti and the tobacco cutworm S. litura

How Bruguiera gymnorhizza seedlings respond to climate change induced salinity rise?

A study was undertaken during August 2017 to evaluate the effect of salinity on chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid and proline contents of hydroponically grown seedlings of Bruguiera gymnorhizza. The primary aim was to observe its tolerance to changing salinity. The selected seedlings were exposed to five different salinity levels (2,5,10,15 and 20psu) for a period of 30 days and observations were done at a regular interval of 7,14,21 and 30 days respectively. The concentrations of chlorophyll exhibited significant positive correlations with salinity (p<0.01). The chlorophyll a:b ratio in the plant varied between 2.39 to 3.71 throughout the period of investigation. The salinity fluctuation did not affect the carotenoid level and proline content in the leaves of the species as evidenced from the insignificant r values. The results show that Bruguiera gymnorhizza of Indian Sundarbans region can tolerate and adapt to high saline condition as witnessed in the central sector of the deltaic complex around the Matla River

Efficacy of chitosan silver nanoparticles from shrimp-shell wastes against major mosquito vectors of public health importance

Mosquito-borne diseases are causing serious damage to public health worldwide, and control of these deadly mosquito vectors is a major thrust area for epidemiologists and public health workers. Therefore, the present research reports an eco-friendly solution with multipotency of silver nanoparticle fabricated from shrimp shell biowaste in controlling mosquitoes and bacterial pathogens. The biofabricated chitosan silver nanoparticles (Cs-AgNPs) were confirmed by UV-visible spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction and zeta potential analysis. The TEM studies showed that the obtained Cs-AgNPs were mostly spherical in shape. Low doses of chitosan and Cs-AgNPs showed high mosquitocidal properties against both larvae and adult of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The LC50 (lethal concentration 50%) of Cs-AgNPs was 10.240 ppm (fourth instar larvae) and 9.671 ppm (adult) for An. stephensi; 11.349 ppm (fourth instar) and 12.015 ppm (adult) for Ae. aegypti and 12.426 ppm (fourth instar) and 12.965 ppm (adult) for Cx. quinquefasciatus. The concerning part of antibacterial studies showed that Cs-AgNP had significant inhibition on tested bacterial pathogens. Overall, this study shows that chitosan extracted from the shrimp shell wastes can be used as a potential source for controlling major mosquito vectors

Convenient Synthesis of Two Mango Allergens

The mango allergens, 5[2’(Z)-heptadecenyl]resorcinol (10) and 5[12’(Z)-heptadecenyl]resorcinol (20) have been synthesized by simple routes using easily accessible starting materials

Decadal Variation of Dissolved Oxygen in the Lower Gangetic Delta Water

We analyzed the Dissolved Oxygen (DO) level in the surface water off Namkhana, a sampling station in the lower Gangetic delta region. Our three decade analysis in three different reasons (premonsoon, monsoon and postmonsoon) exhibits a decrease in the DO value with the passage of time. Based on the DO value we carried out a premilinary Water Quality Index (WQI) analysis using the average seasonal temperature of the study region. This index can be used as proxy to aquatic health in the study site, provided other relevant variables remain within the optimum range. The DO level varies as per the sequence monsoon &gt; postmonsoon &gt; premonsoon. The sudden rise of DO level and WQI during premonsoon 2009 is attributed to Aila, a super cyclone that passed across the lower Gangetic delta on 25th May, 2009 with a speed of ~110 km/hr.</p

Estimation of stored carbon in <i>Sonneratia apetala</i> seedlings collected from Indian Sundarbans

1598-1602Sonneratia apetala grows luxuriantly in the low saline zone of Indian Sundarbans. Considering the carbon storing potential of the species we attempted to identify the best fitting allometric equation with stored carbon per unit area by S. apetala seedlings as the dependent variable and biomasses of vegetative parts of the seedlings (leaf, stem, root and total biomass) separately as independent variables. The sampling was undertaken during monsoon 2016 in two selected stations, Chemaguri and Bali island located in the western and central sectors of the deltaic complex respectively, with contrasting salinity profile. Another purpose of this study was to observe the impact of salinity (if any) on the allometric equations of S. apetala seedlings. We observed that common allometric equation can be used (considering stem and total biomasses of the seedlings as independent variable) to predict the stored carbon per unit area in the seedlings growing in different salinity gradient

Inter-annual variation of salinity in Indian Sundarbans

410-415Using secondary data coupled with real time data, inter-annual variation of surface water salinity in three sectors (western, central and eastern) of Indian Sundarbans during 1984-2013 was studied. Salinity of the aquatic system in the present deltaic complex, situated in the inshore region of Bay of Bengal is primarily regulated by anthropogenic factors (like barrage discharge, run-off from the adjacent landmasses etc.) and natural factors (like siltation, plate tectonics etc.). Surface water salinity has decreased by 0.63 and 0.86 psu per year in the western and eastern sectors respectively, whereas in the central sector, it has increased 1.09 psu per year. Another important objective of the study is to investigate the future salinity (in 2043, 30 years after 2013) in the three sectors of the deltaic complex considering the present data set of 30 years as the baseline. Our forecast through exponential smoothening method reveals an alarming hypersaline environment in the central Indian Sundarbans