Showing papers by "Central University of Kerala published in 2017"

Microbial exopolysaccharide-mediated synthesis and stabilization of metal nanoparticles

Abstract: Exopolysaccharides (EPSs) are structurally and functionally valuable biopolymer secreted by different prokaryotic and eukaryotic microorganisms in response to biotic/abiotic stresses and to survive in extreme environments. Microbial EPSs are fascinating in various industrial sectors due to their excellent material properties and less toxic, highly biodegradable, and biocompatible nature. Recently, microbial EPSs have been used as a potential template for the rapid synthesis of metallic nanoparticles and EPS-mediated metal reduction processes are emerging as simple, harmless, and environmentally benign green chemistry approaches. EPS-mediated synthesis of metal nanoparticles is a distinctive metabolism-independent bio-reduction process due to the formation of interfaces between metal cations and the polyanionic functional groups (i.e. hydroxyl, carboxyl and amino groups) of the EPS. In addition, the range of physicochemical features which facilitates the EPS as an efficient stabilizing or capping a...

Microalgal diversity fosters stable biomass productivity in open ponds treating wastewater

Abstract: It is established that biodiversity determines productivity of natural ecosystems globally. We have proved that abiotic factors influenced biomass productivity in engineered ecosystems i.e. high rate algal ponds (HRAPs), previously. This study demonstrates that biotic factors, particularly microalgal diversity, play an essential role in maintaining stable biomass productivity in HRAP treating municipal wastewater by mutualistic adaptation to environmental factors. The current study examined data from the second year of a two-year study on HRAP treating municipal wastewater. Microalgal diversity, wastewater characteristics, treatment efficiency and several environmental and meteorological factors were documented. Multivariate statistical analyses reveal that microalgae in uncontrolled HRAPs adapt to adverse environmental conditions by fostering diversity. Subsequently, five dominant microalgal strains by biovolume were isolated, enriched, and optimum conditions for high biomass productivity were ascertained. These laboratory experiments revealed that different microalgal strains dominate in different conditions and a consortium of these diverse taxa help in sustaining the algae community from environmental and predatory pressures. Diversity, niche or seasonal partitioning and mutualistic growth are pertinent in microalgal cultivation or wastewater treatment. Therefore, enrichment of selective species would deprive the collective adaptive ability of the consortium and encourage system vulnerability especially in wastewater treatment.

Searching for signatures across microbial communities: Metagenomic analysis of soil samples from mangrove and other ecosystems.

Abstract: In this study, we categorize the microbial community in mangrove sediment samples from four different locations within a vast mangrove system in Kerala, India. We compared this data to other samples taken from the other known mangrove data, a tropical rainforest, and ocean sediment. An examination of the microbial communities from a large mangrove forest that stretches across southwestern India showed strong similarities across the higher taxonomic levels. When ocean sediment and a single isolate from a tropical rain forest were included in the analysis, a strong pattern emerged with Bacteria from the phylum Proteobacteria being the prominent taxon among the forest samples. The ocean samples were predominantly Archaea, with Euryarchaeota as the dominant phylum. Principal component and functional analyses grouped the samples isolated from forests, including those from disparate mangrove forests and the tropical rain forest, from the ocean. Our findings show similar patterns in samples were isolated from forests, and these were distinct from the ocean sediment isolates. The taxonomic structure was maintained to the level of class, and functional analysis of the genes present also displayed these similarities. Our report for the first time shows the richness of microbial diversity in the Kerala coast and its differences with tropical rain forest and ocean microbiome.

Sol-Gel Synthesis of Titanium Dioxide

Abstract: The basic principles of sol-gel synthesis, its advantages and disadvantages along with various applications are discussed. This technique is widely used for making semiconducting metal oxide nanoparticles such as titanium dioxide (TiO2). Depending on the titanium metal precursor type, two different approaches of sol-gel synthesis of TiO2 nanomaterials can be identified and are discussed here: (i) an alcohol-based process where the starting precursor is metal alkoxide and (ii) an aqueous-based process where the starting precursor is inorganic metal salts. The three different phases of TiO2, anatase, rutile and brookite are also discussed. Among the three, anatase is found to be more photocatalytically active than the other two phases. However, anatase was converted into rutile at low temperature; hence, the high-temperature stability of anatase TiO2 and its application as a photocatalyst which has also discussed.

Increased chemical weathering during the deglacial to mid-Holocene summer monsoon intensification

Abstract: Chemical weathering and the ensuing atmospheric carbon dioxide consumption has long been considered to work on geological time periods until recently when some modelling and natural records have shown that the weathering-related CO2 consumption can change at century to glacial-interglacial time scale. Last glacial to interglacial transition period is a best test case to understand the interplay between Pco2-temperature-chemical weathering when a pulse of rapid chemical weathering was initiated. Here we show, from a high resolution 54 ka record from the Andaman Sea in the northern Indian Ocean, that the chemical weathering responds to deglacial to mid-Holocene summer monsoon intensification in the Myanmar watersheds. The multi-proxy data (Al/K, CIA, Rb/Sr, 87Sr/86Sr for degree of weathering and 143Nd/144Nd for provenance) reveal an increase in silicate weathering with initiation of interglacial warm climate at ~17.7 ka followed by a major change at 15.5 ka. Inferred changes in chemical weathering have varied in tandem with the regional monsoonal proxies (δ18Osw-salinity changes of Northern Indian Ocean, effective Asian moisture content and δ18O records of Chinese caves) and are synchronous with changes in summer insolation at 30°N and δ18O of GISP2 implying that chemical weathering was not a later amplifier but worked in tandem with global climate change.

Occurrence of concurrent infections with multiple serotypes of dengue viruses during 2013-2015 in northern Kerala, India.

Abstract: Background Dengue is a global human public health threat, causing severe morbidity and mortality. The occurrence of sequential infection by more than one serotype of dengue virus (DENV) is a major contributing factor for the induction of Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS), two major medical conditions caused by DENV infection. However, there is no specific drug or vaccine available against dengue infection. There are reports indicating the increased incidence of concurrent infection of dengue in several tropical and subtropical regions. Recently, increasing number of DHF and DSS cases were reported in India indicating potential enhancement of concurrent DENV infections. Therefore, accurate determination of the occurrence of DENV serotype co-infections needs to be conducted in various DENV prone parts of India. In this context, the present study was conducted to analyse the magnitude of concurrent infection in northern Kerala, a southwest state of India, during three consecutive years from 2013 to 2015. Methods A total of 120 serum samples were collected from the suspected dengue patients. The serum samples were diagnosed for the presence of dengue NS1 antigen followed by the isolation of dengue genome from NS1 positive samples. The isolated dengue genome was further subjected to RTPCR based molecular serotyping. The phylogenetic tree was constructed based on the sequence of PCR amplified products. Results Out of the total number of samples collected, 100 samples were positive for dengue specific antigen (NS1) and 26 of them contained the dengue genome. The RTPCR based molecular serotyping of the dengue genome revealed the presence of all four serotypes with different combinations. However, serotypes 1 and 3 were predominant combinations of concurrent infection. Interestingly, there were two samples with all four serotypes concurrently infected in 2013. Discussion All samples containing dengue genome showed the presence of more than one serotype, indicating 100% concurrent infection. However, the combination of serotypes 1 and 3 was predominant. To the best of our knowledge, this is the first report indicating the concurrent infection of dengue in the northern Kerala, India. The phylogenetic analysis of dengue serotype 1 identified in this study shows a close relationship with the strain isolated in Delhi and South Korea during the 2006 and 2015 epidemics respectively. Similarly this study indicates that the phylogeny of dengue serotype 3 of northern Kerala is more closely related to dengue isolate of Rajasthan state, India. The geographical and climatic conditions of Kerala favours the breeding of both the mosquito vectors of dengue (Aedes albopictus and Aedes aegypti), which may enhance the severity of dengue in the future. Therefore, the study provides an alarming message for the urgent need of an antiviral strategy or other health management systems to curb the spread of dengue infection.

Production of Bionanomaterials from Agricultural Wastes

Abstract: Nature is gifted with numerous nanomaterials which could be simply prepared from plant materials. Agricultural waste (waste produced on a farm through various farming activities) includes both natural and nonnatural wastes. In the agricultural residues, refuse and wastes create a significant amount of worldwide agricultural productivity. It has variously been estimated that wastes can account for over 30% of worldwide agricultural productivity. The goal of this chapter is to assess the most recent trends to produce bionano nanomaterials from agricultural waste. Nanocellulose extraction from agricultural wastes is a promising substitute for waste treatment, and a few more wide applications of nanocellulose in biological science are much expected in the near future. The most salient nanocellulose applications in this chapter deal with the production and support matrices for enzyme immobilization, biosensors, and antimicrobial agents. Silicon nanoparticles concluded to be one of the elite compounds for the enhancement of agricultural yields.

Experimental Demonstration of Non-local Controlled-Unitary Quantum Gates Using a Five-qubit Quantum Computer

Abstract: Local implementation of non-local quantum gates is necessary in a distributed quantum computer. Here, we demonstrate the non-local implementation of controlled-unitary quantum gates proposed by Eisert et al. (Phys Rev A 62:052317, 2000) using the five-qubit IBM quantum computer. We verify the fidelity and accuracy of the implementation through the techniques of quantum state and process tomographies.

Cultural adaptation of a peer-led lifestyle intervention program for diabetes prevention in India: the Kerala diabetes prevention program (K-DPP)

Abstract: Type 2 diabetes mellitus (T2DM) is now one of the leading causes of disease-related deaths globally. India has the world’s second largest number of individuals living with diabetes. Lifestyle change has been proven to be an effective means by which to reduce risk of T2DM and a number of “real world” diabetes prevention trials have been undertaken in high income countries. However, systematic efforts to adapt such interventions for T2DM prevention in low- and middle-income countries have been very limited to date. This research-to-action gap is now widely recognised as a major challenge to the prevention and control of diabetes. Reducing the gap is associated with reductions in morbidity and mortality and reduced health care costs. The aim of this article is to describe the adaptation, development and refinement of diabetes prevention programs from the USA, Finland and Australia to the State of Kerala, India. The Kerala Diabetes Prevention Program (K-DPP) was adapted to Kerala, India from evidence-based lifestyle interventions implemented in high income countries, namely, Finland, United States and Australia. The adaptation process was undertaken in five phases: 1) needs assessment; 2) formulation of program objectives; 3) program adaptation and development; 4) piloting of the program and its delivery; and 5) program refinement and active implementation. The resulting program, K-DPP, includes four key components: 1) a group-based peer support program for participants; 2) a peer-leader training and support program for lay people to lead the groups; 3) resource materials; and 4) strategies to stimulate broader community engagement. The systematic approach to adaptation was underpinned by evidence-based behavior change techniques. K-DPP is the first well evaluated community-based, peer-led diabetes prevention program in India. Future refinement and utilization of this approach will promote translation of K-DPP to other contexts and population groups within India as well as other low- and middle-income countries. This same approach could also be applied more broadly to enable the translation of effective non-communicable disease prevention programs developed in high-income settings to create context-specific evidence in rapidly developing low- and middle-income countries. Australia and New Zealand Clinical Trials Registry: ACTRN12611000262909 . Registered 10 March 2011.

Greener synthesis of magnetite nanoparticles using green tea extract and their magnetic properties

Abstract: The facile green synthesis method has been employed for the synthesis of biocompatible Fe3O4 magnetic nanoparticles (MNPs) using green tea extract. The effective reduction of ferric ions (Fe3+) were done using an aqueous green tea extract where it acts as reducing as well as capping agent. The effect of iron precursor to green tea extract ratio and reaction temperature was studied. The MNPs were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, dynamic light scattering and vibrating sample magnetometer. It was observed that the reaction temperature strongly affects the magnetic and structural properties of MNPs. The magnetic measurements study showed that Fe3O4 MNPs are superparamagnetic at 300 K, while at 60 K have ferromagnetic as well as superparamagnetic contributions.

Nanoagrotechnology for Soil Quality, Crop Performance and Environmental Management

Abstract: Nanotechnology is emerging as the key enabling technology that contributes to increased crop production with special emphasis on soil protection with environmental sustainability. Increasing worldwide food security and challenging climatic conditions are the key components for encouraging the scientific community to focus on accelerating the growth of nanoagrotechnology. Last few decades immensely contributed to the field of agriculture; technological innovations by several hybrid varieties, synthetic chemical compounds and advanced techniques of biotechnology are an integral part of this achievement. The present decade emerged as the “decade of nanoagrotechnology”, as a new origin of agricultural developments through most groundbreaking scientific finding in the field.

Agricultural Nanotechnology: Concepts, Benefits, and Risks

Abstract: Nanotechnology is one of the utmost significant tools in modern agriculture is predicted to become a driving cost-effective force in the near future. Nanotechnology in agriculture has gained drive in the last decade with an abundance of public funding, but the step of development is uncertain, even though many disciplines come under the agriculture system. This could be attributed to a unique nature of farm production whereby energy and matter are exchanged freely, the scale of demand of input materials constantly being enormous in contrast with industrial nanoproducts. The nanotechnologic intervention in farming has prospects for improving the efficiency of nutrient use through nanoformulations of fertilizers, surveillance and control of pests and diseases, improvement of new-generation pesticides, biosensors (which are exclusively used in remote sensing devices for precision farming), clay-based nanoresources for precision water management, and reclamation of salt-affected lands.

Marine Enzymes: Production and Applications for Human Health.

Abstract: Marine microbial enzymes have wide applications in bioindustries. Selection of microorganisms for enzyme production at the industrial level requires good yield and high production rate. A number of enzymes such as amylase, caseinase, lipase, gelatinase, and DNases have been discovered from microbes isolated from extreme marine environments. Such enzymes are thermostable, tolerant to a varied range of pH and other harsh conditions required in industrial applications. Novelty in their structure and characteristics has shown promising scope to the researchers in academia and industry. In this chapter, we present a bird's eye view on recent research works in the field of enzyme production from marine origin as well as their potential biological applications relevant to human health.

Climatic periodicities recorded in lake sediment magnetic susceptibility data: Further evidence for solar forcing on Indian summer monsoon

Abstract: The Indian summer monsoon exhibits considerable spatio-temporal variability. It is therefore important to understand its dynamics and the inherent periodicities. In this study, we have performed spectral and wavelet analyses of magnetic susceptibility data for sediments from Thimmannanayakanakere (TK)–a small lake in southern India. The main objective of this investigation is to identify and explain the possible origin of the prominent periodicities present in the magnetic susceptibility data. Significant periodicities in the TK χlf data are centered at 906, 232, 147, 128, 96, 61, 54 and 44 years, which might have a solar origin. The wavelet power spectrum of the raw and detrended χlf data confirms the findings of spectral analysis and also provides temporal variations of the significant cyclicities during the past 3700 cal. years B.P. Positive correlation is documented between sunspot activity and TK χlf data; cross-spectral analysis of the reconstructed sunspot data and TK χlf data suggest that there is a strong coherence between the two datasets as significant periodicities are documented in both. There is a good match between the TK χlf and the reconstructed total solar irradiance data for the past 1200 years. However, an out-of-phase relationship is documented at certain time-intervals, which may be attributed to uncertainties in the age-depth model. The results obtained from this study show that solar variations are the main controlling factor of the southwest monsoon and, like other archives from different regions in India, the TK lake sediments have also recorded these solar signatures.

Geochemical systematics of the Mauranipur-Babina greenstone belt, Bundelkhand Craton, Central India: Insights on Neoarchean mantle plume-arc accretion and crustal evolution

Abstract: The Neoarchean Bundelkhand greenstone sequences at Mauranipur and Babina areas within the Bundelkhand Gneissic Complex preserve a variety of magmatic rocks such as komatiitic basalts, basalts, felsic volcanic rocks and high-Mg andesites belonging to the Baragaon, Raspahari and Koti Formations. The intrusive and extrusive komatiitic basalts are characterized by low SiO 2 (39–53 wt.%), high MgO (18–25 wt.%), moderately high Fe 2 O 3 (7.1–11.6 wt.%), Al 2 O 3 (4.5–12.0 wt.%), and TiO 2 (0.4–1.23 wt.%) with super to subchondritic (Gd/Yb) N ratios indicating garnet control on the melts. The intrusive komatiitic suite of Ti-enriched and Al-depleted type possesses predominant negative Eu and positive Nb, Ti and Y anomalies. The chemical composition of basalts classifies them into three types with varying SiO 2 , TiO 2 , MgO, Fe 2 O 3 , Al 2 O 3 and CaO. At similar SiO 2 content of type I and III basalts, the type II basalts show slightly high Al 2 O 3 and Fe 2 O 3 contents. Significant negative anomalies of Nb, Zr, Hf and Ti, slightly enriched LREE with relatively flat HREE and low ∑REE contents are observed in type I and II basalts. Type III basalts show high Zr/Nb ratios (9.8–10.4), TiO 2 (1.97–2.04 wt.%), but possess strikingly flat Zr, Hf, Y and Yb and are uncontaminated. Andesites from Agar and Koti have high SiO 2 (55–64 wt.%), moderate TiO 2 (0.4–0.7 wt.%), slightly low Al 2 O 3 (7–11.9 wt.%), medium to high MgO (3–8 wt.%) and CaO contents (10–17 wt.%). Anomalously high Cr, Co and Ni contents are observed in the Koti rhyolites. Tholeiitic to calc alkaline affinity of mafic-felsic volcanic rocks and basalt–andesite–dacite–rhyolite differentiation indicate a mature arc and thickened crust during the advanced stage of the evolution of Neoarchean Bundelkhand greenstone belt in a convergent tectonic setting where the melts were derived from partial melting of thick basaltic crust metamorphosed to amphibolite-eclogite facies. The trace element systematics suggest the presence of arc-back arc association with varying magnitudes of crust-mantle interaction. La/Sm, La/Ta, Nb/Th, high MgO contents (>20 wt.%), CaO/Al 2 O 3 and (Gd/Yb) N > 1 along with the positive Nb anomalies of the komatiite basalts reflect a mantle plume source for their origin contaminated by subduction-metasomatized mantle lithosphere. The overall geochemical signatures of the ultramafic-mafic and felsic volcanic rocks endorse the Neoarchean plume-arc accretion tectonics in the Bundelkhand greenstone belt.

Invasive ant ( Anoplolepis gracilipes ) disrupts pollination in pumpkin

Abstract: Yellow crazy ant (Anoplolepis gracilipes (F. Smith); “YCA”) is known for its aggressive predatory ability and ability to exert exploitation competition on both native and other invasive ants via floral nectar. We argue that YCA invasion can exert both interference and exploitation competition on legitimate pollinators. In pumpkin fields (Cucurbita maxima L.) of south India, YCA infested the flowers, particularly the pistillate flowers, for nectar foraging. Pumpkin is a honey bee-mediated cross-pollinated monoecious plant that produces disproportionately very few pistillate flowers. We hypothesize that YCA presence in the flowers can affect the visitation rate and foraging time of honey bees in the flowers, the fruit set in pumpkins, and can exert predatory pressure on the honey bees if the bees linger in ant-colonized flowers. Both YCA and honey bees preferred to forage on the limited pistillate flowers in the plants. After colonizing the flowers, YCA did not retreat for hours, even upon disturbance by competitors, such as honey bees. Both the visitation frequency and the foraging time of honey bees were drastically reduced in ant-colonized flowers, and none of the ant-colonized flowers developed into fruits, suggesting that the YCA exert both an ecological and evolutionary pressure on pumpkin. The ants preyed upon about 17% of the honey bees that lingered in ant-colonized flowers, and the time the bees spent foraging predicted the fate of the bees. Exploitation competition exerted by the YCA on pumpkin may have far-reaching consequences for the pollination and productivity of this cash crop.

2-Deoxy Glucose Modulates Expression and Biological Activity of VEGF in a SIRT-1 Dependent Mechanism.

Abstract: Reprogramming of energy metabolism particularly switching over of cells to aerobic glycolysis leading to accumulation of lactate is a hallmark of cancer. Lactate can induce angiogenesis, an important process underlying tumor growth and metastasis. VEGF is one of the most important cytokines which regulate this process and the present study was designed to examine if blocking glycolytic pathway in tumor cells can affect its angiogenic potency with respect to VEGF. For this, the expression and biological activity of VEGF synthesized and secreted by tumor derived cell lines in the presence or absence of 2-deoxy glucose (2-DG), an inhibitor of glycolysis was determined. The results suggested that inhibition of glycolysis using sub-lethal doses of 2-DG down-regulated the expression of VEGF and also significantly reduced its biological activity. Further mechanistic studies revealed that the down regulation of VEGF gene expression by 2-DG was due to an increase in SIRT-1 activity and the reduced biological activity was found to be due to an increase in the PAR modification of VEGF. Activity of SIRT-1 and PAR modification of VEGF in turn, was found to be correlated to the cellular NAD+ levels. The results presented here therefore suggest that treatment of cancer cells with 2-DG can significantly reduce its overall angiogenic potency through transcriptional and post-translational mechanisms. J. Cell. Biochem. 118: 252-262, 2017. © 2016 Wiley Periodicals, Inc.