Space-time clusters and co-occurrence of Plasmodium vivax and Plasmodium falciparum malaria in West Bengal, India.

BACKGROUND: Malaria, a prominent vector borne disease causing over a million annual cases worldwide, predominantly affects vulnerable populations in the least developed regions. Despite their preventable and treatable nature, malaria remains a global public health concern. In the last decade, India has faced a significant decline in malaria morbidity and mortality. As India pledged to eliminate malaria by 2030, this study examined a decade of surveillance data to uncover space-time clustering and seasonal trends of Plasmodium vivax and Plasmodium falciparum malaria cases in West Bengal. METHODS: Seasonal and trend decomposition using Loess (STL) was applied to detect seasonal trend and anomaly of the time series. Univariate and multivariate space-time cluster analysis of both malaria cases were performed at block level using Kulldorff's space-time scan statistics from April 2011 to March 2021 to detect statistically significant space-time clusters. RESULTS: From the time series decomposition, a clear seasonal pattern is visible for both malaria cases. Statistical analysis indicated considerable high-risk P. vivax clusters, particularly in the northern, central, and lower Gangetic areas. Whereas, P. falciparum was concentrated in the western region with a significant recent transmission towards the lower Gangetic plain. From the multivariate space-time scan statistics, the co-occurrence of both cases were detected with four significant clusters, which signifies the regions experiencing a greater burden of malaria cases. CONCLUSIONS: Seasonal trends from the time series decomposition analysis show a gradual decline for both P. vivax and P. falciparum cases in West Bengal. The space-time scan statistics identified high-risk blocks for P. vivax and P. falciparum malaria and its co-occurrence. Both malaria types exhibit significant spatiotemporal variations over the study area. Identifying emerging high-risk areas of P. falciparum malaria over the Gangetic belt indicates the need for more research for its spatial shifting. Addressing the drivers of malaria transmission in these diverse clusters demands regional cooperation and strategic strategies, crucial steps towards overcoming the final obstacles in malaria eradication.

A promising antifungal lipopeptide from Bacillus subtilis: its characterization and insight into the mode of action.

Emerging resistance of fungal pathogens and challenges faced in drug development have prompted renewed investigations into novel antifungal lipopeptides. The antifungal lipopeptide AF3 reported here is a natural lipopeptide isolated and purified from Bacillus subtilis. The AF3 lipopeptide's secondary structure, functional groups, and the presence of amino acid residues typical of lipopeptides were determined by circular dichroism, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The lipopeptide's low minimum inhibitory concentrations (MICs) of 4-8 mg/L against several fungal strains demonstrate its strong antifungal activity. Biocompatibility assays showed that ~ 80% of mammalian cells remained viable at a 2 × MIC concentration of AF3. The treated Candida albicans cells examined by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy clearly showed ultrastructural alterations such as the loss of the cell shape and cell membrane integrity. The antifungal effect of AF3 resulted in membrane permeabilization facilitating the uptake of the fluorescent dyes-acridine orange (AO)/propidium iodide (PI) and FUN-1. Using 1,6-diphenyl-1,3,5-hexatriene (DPH) and 4-(2-[6-(dioctylamino)-2-naphthalenyl] ethenyl)-1-(3-sulfopropyl) pyridinium inner salt (di-8-ANEPPS), we observed that the binding of AF3 to the membrane bilayer results in membrane disruption and depolarization. Flow cytometry analyses revealed a direct correlation between lipopeptide activity, membrane permeabilization (~ 75% PI uptake), and reduced cell viability. An increase in 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence demonstrates endogenous reactive oxygen species production. Lipopeptide treatment appears to induce late-stage apoptosis and alterations to nuclear morphology, suggesting that AF3-induced membrane damage may lead to a cellular stress response. Taken together, this study illustrates antifungal lipopeptide's potential as an antifungal drug candidate. KEY POINTS: • The studied lipopeptide variant AF3 displayed potent antifungal activity against C. albicans • Its biological activity was stable to proteolysis • Analytical studies demonstrated that the lipopeptide is essentially membranotropic and able to cause membrane dysfunction, elevated ROS levels, apoptosis, and DNA damage.

Microbial lipopeptides: their pharmaceutical and biotechnological potential, applications, and way forward.

As lead molecules, cyclic lipopeptides with antibacterial, antifungal, and antiviral properties have garnered a lot of attention in recent years. Because of their potential, cyclic lipopeptides have earned recognition as a significant class of antimicrobial compounds with applications in pharmacology and biotechnology. These lipopeptides, often with biosurfactant properties, are amphiphilic, consisting of a hydrophilic moiety, like a carboxyl group, peptide backbone, or carbohydrates, and a hydrophobic moiety, mostly a fatty acid. Besides, several lipopeptides also have cationic groups that play an important role in biological activities. Antimicrobial lipopeptides can be considered as possible substitutes for antibiotics that are conventional to address the current drug-resistant issues as pharmaceutical industries modify the parent antibiotic molecules to render them more effective against antibiotic-resistant bacteria and fungi, leading to the development of more resistant microbial strains. Bacillus species produce lipopeptides, which are secondary metabolites that are amphiphilic and are typically synthesized by non-ribosomal peptide synthetases (NRPSs). They have been identified as potential biocontrol agents as they exhibit a broad spectrum of antimicrobial activity. A further benefit of lipopeptides is that they can be produced and purified biotechnologically or biochemically in a sustainable manner using readily available, affordable, renewable sources without harming the environment. In this review, we discuss the biochemical and functional characterization of antifungal lipopeptides, as well as their various modes of action, method of production and purification (in brief), and potential applications as novel antibiotic agents.

Generation of higher harmonics in dipolar Bose-Einstein condensates trapped in periodically modulated potentials.

We consider a quasi-one-dimensional Bose-Einstein condensate with contact and long-range dipolar interactions, under the action of the time-periodic modulation applied to the harmonic-oscillator and optical-lattice trapping potentials. The modulation results in generation of a variety of harmonics in oscillations of the condensate's width and centre-of-mass coordinate. These include multiple and combinational harmonics, represented by sharp peaks in the system's spectra. Approximate analytical results are produced by the variational method, which are verified by systematic simulations of the underlying Gross-Pitaevskii equation. This article is part of the theme issue 'New trends in pattern formation and nonlinear dynamics of extended systems'.

Spatial accessibility modeling to healthcare facilities in the case of health shocks of Midnapore municipality, India.

This research aims to identify the accessibility of the entire population, especially the slum population to existing healthcare facilities (HCF) as well as the slum neighborhoods having low geographic accessibility, and finally, to provide an analytical model for the people living in areas that are outside the coverage range of existing healthcare facilities (HCF) across the study area. Spatial data has been collected and used based on the road network, elevation, location of HCF, municipal boundary, slum point, and satellite images from various sources. Also, non-spatial data such as socioeconomic variables are collected from questionnaires survey within a particular period. The spatial analysis tool like as near, network analysis, and predictive analysis in the ArcGIS platform was used to examine geographic accessibility. The results of the spatial analysis show that the distribution of public healthcare facility centers in the study area has not been uniformly distributed. Across 84% of areas in the study area have sound spatial accessibility with traveling time coverage is about 12 min. However, 16% of areas have a traveling time of 12 to 30 min under low accessibility with existing slum neighborhoods. Therefore, the low spatial accessibility areas are demanding new healthcare facilities in the study area. The Analytical Hierarchy Process (AHP) is employed to find the most optimal and efficient locational suitability for building new healthcare facility centers. The finding of AHP analysis for site suitability of healthcare facilities revealed five major classes as most suitable (2%), suitable (5%), moderate (35%), poor (54%), and very poor (4%) in the study area. Moreover, the realistic framework of this study helps to measure geographic accessibility and suitability in any geographical area.

Low-Temperature Annealing of CdZnTeSe under Bias.

We performed a gradual low-temperature annealing up to 360 K on a CdZnTeSe radiation detector equipped with gold and indium electrodes under bias at both polarities. We observed significant changes in the detector's resistance and space-charge accumulation. This could potentially lead to the control and improvement of the electronic properties of the detector because the changes are accompanied with the reduction in the bulk dark current and surface leakage current. In this article, we present the results of a detailed study of the internal electric field and conductivity changes in CdZnTeSe detector for various annealing steps under bias taking into account different polarities during annealing and subsequent characterization. We observed that low-temperature annealing results in an increase in the barrier height at the contacts that, in general, reduces the dark current and decreases the positive space charge present in the sample compared to the pre-annealed condition.

Ultrastructural changes in methicillin-resistant Staphylococcus aureus (MRSA) induced by a novel cyclic peptide ASP-1 from Bacillus subtilis: A scanning electron microscopy (SEM) study.

Increasing antimicrobial resistance among Staphylococcus aureus necessitates a new antimicrobial with a different site of action. We have isolated a novel cyclic peptide-1 (ASP-1) from Bacillussubtilis with potent activity against methicillin-resistant S. aureus (MRSA) at a minimum inhibitory concentration (MIC) of 8-64µg/ml. Scanning electron micrographs demonstrated drastic changes in the cellular architecture of ASP-1 treated cells of S. aureus ATCC 29213 and an MRSA clinical isolate at MICs, with damages to the cell wall, membrane lysis and probable leakage of cytoplasmic contents at minimum bactericidal concentrations. The ultrastructure alterations induced by ASP-1 have also been compared with those of oxacillin-treated MRSA cells at its MIC using scanning electron microscopy.

A capacitive DNA sensor for sensitive detection of Escherichia coli O157:H7 in potable water based on the z3276 genetic marker: fabrication and analytical performance.

We report a label-free biosensor for the detection of Escherichia coli O157:H7 ATCC 43895 in potable water using a newly designed DNA sensing probe targeting the z3276 genetic marker. The surface of indium tin oxide (ITO) was functionalized with the novel sensing probe by covalent coupling using APTES as a crosslinker to fabricate the DNA sensor (dubbed ZEC [z[combining low line]3276 gene of E[combining low line]. c[combining low line]oli O157:H7 ATCC 43895]). The electrochemical characterization of the fabricated ZEC sensor was performed using cyclic voltammetry and electrochemical impedance spectroscopy. Atomic force microscopy and scanning electron microscopy revealed significant changes in the surface topographies of the fabricated ZEC sensor chip. Equivalent circuit analyses suggested the capacitive nature of the ZEC sensor chip, which demonstrated a declining trend of the capacitance value from 1.568 µF (Bare ITO) to 1.221 µF (after DNA hybridization). Non-faradaic sensing measurements revealed systematically declining capacitance values upon DNA hybridization, with a 10 min response time at 10 Hz frequency and 10 mV applied potential. The ZEC sensor chip exhibited linearity in the range of 0.5 to 25 pg per 10 mL for E. coli O157:H7, with ubiquitous cross-validation of each DNA concentration using quantitative PCR prior to the analyses of real water samples. The limit of detection (LOD) at 95% confidence estimated by logistic regression was 0.1 pg DNA per 10 mL of E. coli O157:H7 (equivalent to 13.67 CFU per 10 mL) with a p-value of 0.0237. Consequently, the obtained results demonstrate the possible application of the developed ZEC sensor chip for E. coli O157:H7 detection in real water samples.

Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging.

Cadmium zinc telluride selenide (Cd1-xZnxTe1-ySey or CZTS) is one of the emerging CdTe-based semiconductor materials for detecting X- and gamma-ray radiation at or near room temperature (i.e., without cryogenic cooling). Potential applications of CZTS sensors include medical imaging, X-ray detection, and gamma-ray spectroscopy. Chemical passivation of CZTS is needed to reduce the conductivity of Te-rich surfaces, which reduces the noise and improves the device performance. In this study, we focus on the effect of surface passivation of CZTS using a 10% aqueous solution of ammonium fluoride. The effects of the chemical treatment were studied on the leakage current, charge transport measured as the electron mobility-lifetime (µτ) product, and the spectral resolution measured as the full-width at half-maximum (FWHM) of specific peaks. After passivation, the leakage current increased and began to decrease towards pre-passivation levels. The energy resolutions were recorded for eight applied voltages between -35 V and -200 V. The results showed an average of 25% improvement in the detector's energy resolution for the 59.6 keV gamma peak of Am-241. The electron µτ product was unchanged at 2 × 10-3 cm2/V. These results show that ammonium fluoride is effective for chemical passivation of CZTS detectors.

A New Functional Model for Prediction of Chaperone Activity of the Recombinant M. tb Acr (α-Crystallin) Using Insulin as Substrate.

Mycobacterium tuberculosis Acr is an important protein expressed in latent tuberculosis which is active as an oligomer in preventing misfolding of cellular proteins. In this study, Mycobacterium alpha crystallin (acr) gene was cloned and expressed in Escherichia coli (E. coli). The recombinant Acr protein was purified by Nickel-NTA resin. The oligomeric state of Acr was confirmed by gel filtration chromatography using Sephacryl S-200 and Native-PAGE. Studies of chaperone activity were performed with insulin as a substrate at different mole ratios of Acr with 2 types of samples, His tag elutes (H) and His tag elutes with gel filtration (G). It was observed that the ratio of different sizes of oligomers (9 to 24 mers) had a significant effect on chaperone activity. Using the mole ratio of Acr for both (H) and (G) samples to insulin B chain and ratio of oligomers, we determined the number of Acr molecules binding to insulin as a model substrate. We found that if 1.5% of the insulin B chains are covered completely by the (G) samples, aggregation is completely inhibited as compared to 6% with (H) samples. Pre-heat treatment studies were carried out at 37°C, 60°C, and 70°C. Far-ultraviolet Circular Dichroism (UV-CD) analysis provided fresh insights into the role of ß-sheets and α-helices in chaperone activity, particularly in (H) samples suggesting a reversible conformational transition from helices to sheets. This enabled us to formulate a functional model for binding of Acr to insulin B chains which incorporated 4 types of secondary structure molecules. This might be a useful tool for analyzing in vitro preparations of recombinant Acr and build more consensuses on the structure-activity relationship especially in terms of oligomeric ratios.

Evaluation of Antifungal Efficacy of Three New Cyclic Lipopeptides of the Class Bacillomycin from Bacillus subtilis RLID 12.1.

New lipopeptide homologues (AF3, AF4, and AF5) with antifungal activities against Candida and Cryptococcus spp. were purified from a cell-free supernatant of Bacillus subtilis RLID 12.1. The lipopeptides AF3, AF4, and AF5 were identified with the same peptide sequence Asn-Pro-Tyr-Asn-Gln-Thr-Ser with variations in the fatty acid branching type and chain length (anteiso-C17, iso-C17, and iso-C18, respectively). Upon comparing the three homologues for MICs against 81 Candida (n = 64) and Cryptococcus (n = 17) clinical isolates and their cytotoxicities, we found that AF4 was the most promising antifungal lipopeptide, since it demonstrated 100% inhibition at geometric mean MICs of 3.31, 3.41, 3.48, and 2.83 µg/ml against Candida albicans, Candida tropicalis, Candida auris, and Cryptococcus neoformans, respectively, with low hemolysis values (<6%) and 50% inhibitory concentrations (13.31 µg/ml). The additive effects among the homologues AF3, AF4, and AF5 were evaluated against three Candida species, along with the cytotoxicity studies. Five combinations exhibited good additive interaction effects: AF3/AF4 (at corresponding concentrations of 4 and 4 µg/ml [4/4 µg/ml]), AF3/AF5 (4/4 µg/ml), AF3/AF5 (2/4 µg/ml), AF4/AF5 (4/4 µg/ml), and AF4/AF5 (2/4 µg/ml) in planktonic cell inhibition and AF3/AF4 (4/4 µg/ml), AF3/AF5 (4/4 µg/ml), and AF3/AF5 (2/4 µg/ml) in the inhibition of biofilm formation. However, combinations AF3/AF4 and AF3/AF5, which showed >70% cell survival with low hemolysis (<5%), were found to be comparatively effective. We describe here the additive effects of lipopeptide homologues showing reduced cytotoxicity against mammalian cells; these combinations might serve as a potent antibiofilm-forming substitute.

Bacterial communities in ancient permafrost profiles of Svalbard, Arctic.

Permafrost soils are unique habitats in polar environment and are of great ecological relevance. The present study focuses on the characterization of bacterial communities from permafrost profiles of Svalbard, Arctic. Counts of culturable bacteria range from 1.50 × 103 to 2.22 × 105 CFU g-1 , total bacterial numbers range from 1.14 × 105 to 5.52 × 105 cells g-1 soil. Bacterial isolates are identified through 16S rRNA gene sequencing. Arthrobacter and Pseudomonas are the most dominant genera, and A. sulfonivorans, A. bergeri, P. mandelii, and P. jessenii as the dominant species. Other species belong to genera Acinetobacter, Bacillus, Enterobacter, Nesterenkonia, Psychrobacter, Rhizobium, Rhodococcus, Sphingobacterium, Sphingopyxis, Stenotrophomonas, and Virgibacillus. To the best of our knowledge, genera Acinetobacter, Enterobacter, Nesterenkonia, Psychrobacter, Rhizobium, Sphingobacterium, Sphingopyxis, Stenotrophomonas, and Virgibacillus are the first northernmost records from Arctic permafrost. The present study fills the knowledge gap of culturable bacterial communities and their chronological characterization from permafrost soils of Ny-Ålesund (79°N), Arctic.

Taxonomic characterization and the bio-potential of bacteria isolated from glacier ice cores in the High Arctic.

Glacier ice and firn cores have ecological and biotechnological importance. The present study is aimed at characterizing bacteria in crustal ice cores from Svalbard, the Arctic. Counts of viable isolates ranged from 10 to 7000 CFU/ml (mean 803 CFU/ml) while the total bacterial numbers ranged from 7.20 × 10(4) to 2.59 × 10(7) cells ml(-1) (mean 3.12 × 10(6) cells ml(-1) ). Based on 16S rDNA sequence data, the identified species belonged to seven species, namely Bacillus barbaricus, Pseudomonas orientalis, Pseudomonas oryzihabitans, Pseudomonas fluorescens, Pseudomonas syncyanea, Sphingomonas dokdonensis, and Sphingomonas phyllosphaerae, with a sequence similarity ranging between 93.5 and 99.9% with taxa present in the database. The isolates exhibited unique phenotypic properties, and three isolates (MLB-2, MLB-5, and MLB-9) are novel species, yet to be described. To the best of our knowledge, this is the first report on characterization of cultured bacterial communities from Svalbard ice cores. We conclude that high lipase, protease, cellulase, amylase, and urease activities expressed by most of the isolates provide a clue to the potential industrial applications of these organisms. These microbes, producing cold-adapted enzymes may provide an opportunity for biotechnological research.

Ecotoxicological assessment of tannery effluent using guppy fish (Poecilia reticulata) as an experimental model: a biomarker study.

Tannery wastewater in the East Calcutta Wetlands (a Ramsar site of West Bengal; number 1208) exerts adverse effects on commercial fish production and subsequently affects humans. The present study was conducted to investigate acute and chronic toxicity of tannery effluent on a fish biosystem by examining oxidative stress enzyme expression in different organs including liver, gills, and muscle following exposure. Phosphatases, both alkaline phosphatase and acid phosphatase, and antioxidant superoxide dismutase and catalase enzyme activities were determined in guppy fish (Poecilia reticulata) exposed to sublethal concentrations of composite tannery effluent. Data demonstrated that tannery effluent was capable of interfering with metabolic processes of fish by altering stress enzyme activities in fish organs, resulting in cellular injury. Data suggest that elevated activities of stress enzymes in fish upon exposure to environmental pollutants may serve as important biomarkers for oxidative stress.

A broad-spectrum antimicrobial activity of Bacillus subtilis RLID 12.1.

In the present study, an attempt was made to biochemically characterize the antimicrobial substance from the soil isolate designated as RLID 12.1 and explore its potential applications in biocontrol of drug-resistant pathogens. The antimicrobial potential of the wild-type isolate belonging to the genus Bacillus was determined by the cut-well agar assay. The production of antimicrobial compound was recorded maximum at late exponential growth phase. The ultrafiltered concentrate was insensitive to organic solvents, metal salts, surfactants, and proteolytic and nonproteolytic enzymes. The concentrate was highly heat stable and active over a wide range of pH values. Partial purification, zymogram analysis, and TLC were performed to determine the preliminary biochemical nature. The molecular weight of the antimicrobial peptide was determined to be less than 2.5 kDa in 15% SDS-PAGE and in zymogram analysis against Streptococcus pyogenes. The N-terminal amino acid sequence by Edman degradation was partially determined to be T-P-P-Q-S-X-L-X-X-G, which shows very insignificant identity to other antimicrobial peptides from bacteria. The minimum inhibitory concentrations of dialysed and partially purified ion exchange fractions were determined against some selected gram-positive and gram-negative bacteria and some pathogenic yeasts. The presence of three important antimicrobial peptide biosynthesis genes ituc, fend, and bmyb was determined by PCR.

Two promising natural lipopeptides from Bacillus subtilis effectively induced membrane permeabilization in Candida glabrata.

Candida glabrata is an important opportunistic human pathogen well known to develop resistance to antifungal drugs. Due to their numerous desirable qualities, antimicrobial lipopeptides have gained significant attention as promising candidates for antifungal drugs. In the present study, two bioactive lipopeptides (AF4 and AF5 m/z 1071.5 and 1085.5, respectively), coproduced and purified from Bacillus subtilis RLID12.1, consist of seven amino acid residues with lipid moieties. In our previous studies, the reversed phased-HPLC purified lipopeptides demonstrated broad-spectrum of antifungal activities against over 110 Candida albicans, Candida non-albicans and mycelial fungi. Two lipopeptides triggered membrane permeabilization of C. glabrata cells, as confirmed by propidium iodide-based flow cytometry, with PI uptake up to 99% demonstrating fungicidal effects. Metabolic inactivation in treated cells was confirmed by FUN-1-based confocal microscopy. Together, the results indicate that these lipopeptides have potentials to be developed into a new set of antifungals for combating fungal infections.

Two promising Bacillus-derived antifungal lipopeptide leads AF4 and AF5 and their combined effect with fluconazole on the in vitro Candida glabrata biofilms.

Introduction: Candida species are endowed with the ability to produce biofilms, which is one of the causes of pathogenicity, as biofilms protect yeasts from antifungal drugs. Candida glabrata (Nakaseomyces glabrata) is one of the most prevalent pathogenic yeasts in humans and a biofilm producer. Methods: The study was aimed at evaluating the combined effects of two highly promising antifungal biomolecules (AF4 and AF5) lipopeptide in nature, chromatographically purified to homogeneity from Bacillus subtilis (B. subtilis) and the standard antifungal fluconazole (at different concentrations) to demonstrate C. glabrata biofilm formation inhibition. Biofilm production and inhibition were evaluated by quantification of the biofilm biomass and metabolic activity using crystal violet (CV) staining and XTT reduction assays, respectively. Microscopic techniques such as confocal scanning laser microscopy (CSLM) and scanning electron microscopy (SEM) were employed to visualize biofilm formation and inhibition. Results and Discussion: Compared to untreated and fluconazole-treated biofilms, an enhanced in vitro anti-biofilm effect of the antifungal lipopeptides AF4/AF5 alone and their combinations with fluconazole was established. The lipopeptides AF4/AF5 alone at 8 and 16 µg/mL exhibited significant biomass and metabolic activity reductions. SEM and CSLM images provided evidence that the lipopeptide exposure results in architectural alterations and a significant reduction of C. glabrata biofilms, whereas (2', 7'-dichlorofluorescin diacetate (DCFDA) and propidium iodide (PI) analyses showed reactive oxygen species (ROS) generation along with membrane permeabilization. The estimation of exopolysaccharides (EPS) in AF4/AF5-treated biofilms indicated EPS reduction. The combinations of fluconazole (64/128 µg/mL) and AF4/AF5 lipopeptide (16 µg/mL) were found to significantly disrupt the mature (24 h) biofilms as revealed by CSLM and SEM studies. The CSLM images of biofilms were validated using COMSTAT. The FTIR-analyses indicate the antibiofilm effects of both lipopeptides on 24 h biofilms to support CSLM and SEM observations. The combinations of fluconazole (64/128 µg/mL) and AF4/AF5 lipopeptide were found to disrupt the mature biofilms; the study also showed that the lipopeptides alone have the potentials to combat C. glabrata biofilms. Taken together, it may be suggested that these lipopeptide leads can be optimized to potentially apply on various surfaces to either reduce or nearly eradicate yeast biofilms.

Quantum scissor from exact generalized photon number statistics.

We report the close form expressions of the photon number statistics for a generalized coherent state and a generalized photon-added coherent state, which are shown to be crucial for proposing a variety of quantum scissor operations. The analytically obtained distributions are also capable of predicting the precise laser intensity windows for realizing a variety of quantum scissors. Truncating a photon added state overcomes the selection rule of obtaining the lower order Fock states. Photon addition also enables us to obtain a higher order Fock state in a lower order superposition. The importance of circular geometry is also demonstrated for engineering such quantum scissors.

Taxonomic characterization, adaptation strategies and biotechnological potential of cryophilic yeasts from ice cores of Midre Lovénbreen glacier, Svalbard, Arctic.

Ten strains of cryophilic yeast were studied from glacier ice cores of Svalbard, Arctic. The ice melt samples contained about 3×10(3) - 1×10(4) colony forming unit (CFUs) per ml. Sequence analysis of the isolates, using D1/D2 domain identified five species of yeasts: Cryptococcus adeliensis (MLB-18 JX192655), Cryptococcus albidosimilis (MLB-19 JX192656), Cryptococcus saitoi (MLB-22 JX192659), Rhodosporidium lusitaniae (MLB-20 JX192657), and Rhodotorula mucilaginosa (MLB-27 JX192664). Effect of temperature on growth of these isolates was studied. The strains are able to grow at temperatures ranging between 1 and 20°C. Screening of the cultures for amylase, cellulase, protease, lipase, urease and catalase activity were carried out indicating varying amounts of enzyme production at different temperatures. Characterization of lipase in strain Cryptococcus sp. MLB-24 was performed. Fatty acid methyl ester (FAME) analysis of the cultures grown at four different temperatures (1, 4, 15, and 20°C) was also done. Decrease in temperature was reported to cause increase in concentration of unsaturated fatty acids. High amount of oleic acid accumulated with increase in temperature. These fatty acids possibly help the strains to survive in glacial ice core cold environment. The extracellular and intracellular filtrate of the cultures showed negative antifreeze protein (AFP) activity. The observations indicate that probably the isolates in the present undertaking adapt to low temperatures, by enzyme and PUFA secretion rather than by antifreeze protein secretion.

The elucidation of the multimodal action of the investigational anti-Candida lipopeptide (AF4) lead from Bacillus subtilis.

Background: Candida species are the main etiological agents for candidiasis, and Candida albicans are the most common infectious species. Candida species' growing resistance to conventional therapies necessitates more research into novel antifungal agents. Antifungal peptides isolated from microorganisms have potential applications as novel therapeutics. AF4 a Bacillus-derived lipopeptide demonstrating broad-spectrum antifungal activity has been investigated for its ability to cause cell death in Candida species via membrane damage and oxidative stress. Methods: Using biophysical techniques, the secondary structure of the AF4 lipopeptide was identified. Scanning electron microscopy and confocal microscopy with fluorescent dyes were performed to visualise the effect of the lipopeptide. The membrane disruption and permeabilization were assessed using the 1,6-diphenyl hexatriene (DPH) fluorescence assay and flow cytometric (FC) assessment of propidium iodide (PI) uptake, respectively. The reactive oxygen species levels were estimated using the FC assessment. The induction of apoptosis and DNA damage were studied using Annexin V-FITC/PI and DAPI. Results: Bacillus-derived antifungal variant AF4 was found to have structural features typical of lipopeptides. Microscopy imaging revealed that AF4 damages the surface of treated cells and results in membrane permeabilization, facilitating the uptake of the fluorescent dyes. A loss of membrane integrity was observed in cells treated with AF4 due to a decrease in DPH fluorescence and a dose-dependent increase in PI uptake. Cell damage was also determined from the log reduction of viable cells treated with AF4. AF4 treatment also caused elevated ROS levels, induced phosphatidylserine externalisation, late-stage apoptosis, and alterations to nuclear morphology revealed by DAPI fluorescence. Conclusion: Collectively, the mode of action studies revealed that AF4 acts primarily on the cell membrane of C. albicans and has the potential to act as an antifungal drug candidate.