Selenium nanoparticles (SeNPs) are gaining importance in the field of medicines due to their high surface area and unique properties than their other forms of selenium. In this study, biogenic selenium nanoparticles (B-SeNPs) were... more
Selenium nanoparticles (SeNPs) are gaining importance in the field of medicines due to their high surface area and unique properties than their other forms of selenium. In this study, biogenic selenium nanoparticles (B-SeNPs) were synthesized using cyanobacteria and their bioactivities (antioxidant, antimicrobial, anticancer and biocompatibility) were determined for comparison with commercially available chemically synthesized selenium nanoparticles (C-SeNPs). Color change of reaction mixture from sky blue to orange-red indicated the synthesis of biogenic SeNPs (B-SeNPs). UV–Vis spectra of the reaction mixture exhibited peak at 266 nm. During optimization, 30 °C of temperature, 24 h of time and 1:2 concentration ratio of sodium selenite and cell extract represented the best condition for SeNPs synthesis. Various functional groups and biochemical compounds present in the aqueous extract of Anabaena variabilis NCCU-441, which may have possibly influenced the reduction process of SeNPs...
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Heme containing proteins are associated with peroxidase activity. The proteins like hemoglobin, myoglobins, cytochrome c and micro-peroxidase other than peroxidases have been shown to exhibit weak peroxidase-like activity. This weak... more
Heme containing proteins are associated with peroxidase activity. The proteins like hemoglobin, myoglobins, cytochrome c and micro-peroxidase other than peroxidases have been shown to exhibit weak peroxidase-like activity. This weak peroxidase-like activity in hemoglobin-like molecules is due to heme moiety. We conducted molecular dynamics (MD) studies to decipher the unfolding path of Ba-Glb (a truncated hemoglobin from Bacillus anthracis) and the role of heme moiety to its unfolding path. The similar unfolding path is also observed in vitro by UV/VIS spectroscopy. The data confirmed that the unfolding of Ba-Glb follows a three state process with a meta-stable (intermediate) state between the native and unfolded conformations. The present study is supported by several unfolding parameters like root-mean-square-deviation (RMSD), dictionary of protein secondary structure (DSSP), and free energy landscape. Understanding the structure of hemoglobin like proteins in unicellular dreaded pathogens like B. anthracis will pave way for newer drug discovery targets and in the disease management of anthrax.
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Biofilms are microbial colonies that are encased in an organic polymeric matrix and are resistant to antimicrobial treatments. Biofilms can adhere to both biotic and abiotic surfaces, allowing them to colonize medical equipment such as... more
Biofilms are microbial colonies that are encased in an organic polymeric matrix and are resistant to antimicrobial treatments. Biofilms can adhere to both biotic and abiotic surfaces, allowing them to colonize medical equipment such as urinary and intravenous catheters, mechanical heart valves, endotracheal tubes, and prosthetic joints. Candida albicans biofilm is the major etiological cause of the pathogenesis of candidiasis in which its unobstructed growth occurs in the oral cavity; trachea, and catheters that progress to systemic infections in the worst scenarios. There is an urgent need to discover novel biofilm preventive and curative agents. In the present investigation, an effort is made to observe the role of cyanobacteria-derived AgNPs as a new antibiofilm agent with special reference to candidiasis. AgNPs synthesized through the green route using Anabaena variabilis cell extract were characterized by UV–visible spectroscopy. The nanoparticles were spherical in shape with 1...
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Across the world, paddy fields naturally harbour cyanobacteria that function as biofertilizers and secrete various compounds like Indole-3-acetic acid (IAA) that help organisms in regulating their growth. Also, paddy field farming... more
Across the world, paddy fields naturally harbour cyanobacteria that function as biofertilizers and secrete various compounds like Indole-3-acetic acid (IAA) that help organisms in regulating their growth. Also, paddy field farming utilizes large amounts of pesticides (e.g. atrazine); but their continued application in the agricultural field causes toxicity in non-target cyanobacterial species that hinder their performance as a biofertilizer. Hence, the current study is an attempt to ameliorate the atrazine stress in cyanobacterium Cylindrospermum stagnale by addition of IAA (1 mM each) under different atrazine levels (0, 60, 80, 100, 120, 140 µg/l). Atrazine toxicity affected C. stagnale in a dose-dependent manner further experiments revealed that both the exogenous and endogenous IAA mitigated the detrimental effects of atrazine. It reduced MDA content and simultaneously increased chlorophyll content, total protein content, and multiple antioxidant enzyme activities [superoxide dis...
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Phycoerythrin (PE) is a light harvesting red protein, found only in cyanophyta, rhodophyta, glaucophyta and cryptophyta. Till now, red algae are well characterized and exploited commercially for PE. High cost of PE (50-3600 US$ /mg), has... more
Phycoerythrin (PE) is a light harvesting red protein, found only in cyanophyta, rhodophyta, glaucophyta and cryptophyta. Till now, red algae are well characterized and exploited commercially for PE. High cost of PE (50-3600 US$ /mg), has compelled the scientists to look for its alternate sources. During present cyanobacterial screening, Microchaete yielded maximum PE (26.32 mg/g), which was further purified on DEAE-cellulose column using sodium acetate buffer (pH-5.5). In final step, purity value of analytical grade PE (5.12) was obtained that showed 21.8 kDa band corresponding to α-subunit of B-PE. 30oC temperature, 12.5 μmol photons/m-2/s light, green wavelength, pH-8, 16:8 photoperiod and 50 mM salinity were the best conditions for maximum PE production. Pesticides (malathion and chlorpyriphos) and heavy metal (Cd2+, Cr6+) showed PE reduction whereas (Cu2+, Zn2+, Pb2+) showed PE enhancement at lower concentrations.
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Present study screened ten Cyanobacterial extracts for antimicrobial activity, cytotoxicity (against human cervical carcinoma cells Hela and SiHa) & GC-MS for chemical composition. Cyanobacterial extracts were subjected to Agar Well... more
Present study screened ten Cyanobacterial extracts for antimicrobial activity, cytotoxicity (against human cervical carcinoma cells Hela and SiHa) & GC-MS for chemical composition. Cyanobacterial extracts were subjected to Agar Well Diffusion Assay at concentration of 100µg. well-1and incubated at 37+ 2oC. Inhibition zone was measured in millimetres (mm) after 18-24 hour. Minimum inhibitory concentration (MIC) was determined by using the broth microdilution method in 96-well microtitre plates. Drug dilutions were performed using cation adjusted Mueller Hinton Broth (MHB) in a concentration range of 128-0.25 μg.ml-1 . Cytotoxicities were assessed using MTT assay. GCMS analysis was carried out on a GCMS-QP 2010 Plus Shimadzu system having RTX-5 column (Restek, USA) (60 m,ID 0.25mm, film thickness 0.25 µm). Cyanobacterial extracts exhibited significant antibacterial effect on clinical isolates of S.aureus MRSA & MRSE whereas selectively inhibited Gram-negative. Minimum inhibitory conce...
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The present study was aimed at exploring 37 strains of cyanobacteria for the biofabrication of TiO2 NP and evaluation of their antioxidant, antifungal, antibacterial and hemolytic activity. Screening of cyanobacterial strains was done via... more
The present study was aimed at exploring 37 strains of cyanobacteria for the biofabrication of TiO2 NP and evaluation of their antioxidant, antifungal, antibacterial and hemolytic activity. Screening of cyanobacterial strains was done via SEM, followed by optimisation and characterisation of the best strain. Synechocystis NCCU-370 appeared as the best strain for the synthesis of TiO2 NP in terms of size (73.39 nm) and time (24 h) after screening. Following optimisation, nanoparticles were synthesised in 12 h having an average grain size of 16 nm. The aqueous extract preparation required heating of 5 mg/ml of powdered biomass to 60 °C for 10 min. Optimum conditions for the synthesis of TiO2 NP were found to be pH 7, 30 °C and 12-h cell extract exposure to 0.1 mM of salt. Antioxidant activity was evaluated via DPPH, ABTS and FRAP assay. Antifungal potential was explored against Candida albicans (MIC = 125 µg/ml), Candida glabrata (MIC = 500 µg/ml) and Candida tropicalis (MIC = 250 µg/ml), whereas antibacterial potential was gauged for Bacillus cereus (MIC = 31.25 µg/ml), Escherichia coli (MIC = 31.25 µg/ml) and Klebsiella pneumoniae (MIC = 500 µg/ml) strains. Biogenic TiO2 NP demonstrated partial synergistic effect and excellent biocompatibility.
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Background: Garlic, being a well-known medicinal plant is the most commonly used culinary spice worldwide. Investigation of protease inhibitor isolated from garlic leads to a promising contender in pharmacognostic and pharmacological... more
Background: Garlic, being a well-known medicinal plant is the most commonly used culinary spice worldwide. Investigation of protease inhibitor isolated from garlic leads to a promising contender in pharmacognostic and pharmacological studies. Objective/Introduction: Protease Inhibitor (PI) from 'garlic' (Allium sativum) was analyzed for its biological role as an antioxidant, antimicrobial, and anti-inflammatory agent. Methods: Antioxidant activity was evaluated using ferric ion reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. The anti-inflammatory activity was assessed using trypsin inhibitory assay and heat-induced albumin denaturation method. The antimicrobial activity was examined in broth against E. coli and B. Subtilis. The crystallization was setup using the hanging drop method. Results: ASPI showed DPPH radical scavenging with IC50 values 561±0.337 µg/ml. Also, ASPI showed the highest value of 0.699±0.009 mM at 1000 μg/ml and the low...
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Due to unique properties of the nanoparticles (NPs) with biocompatibility, their application as drug in drug delievery and diagnostics, the recent scientific branch nanotechnology has emerged as hope in modern medicine. Zinc oxide... more
Due to unique properties of the nanoparticles (NPs) with biocompatibility, their application as drug in drug delievery and diagnostics, the recent scientific branch nanotechnology has emerged as hope in modern medicine. Zinc oxide nanoparticles (ZnO NPs) have gained tremendous interest due to their potential use as chemotherapeutic and antimicrobial agents. They are included in the category of "generally recognized as safe (GRAS) metal oxide". There is an urgent need for developing additional sources of ZnO NPs. Therefore, in the present study 30 cyanobacterial extracts were screened for ZnO NPs synthesis.. The color change of the reaction mixture from blue to pale white indicated the synthesis of ZnO NPs. It was further confirmed by UV-Visible spectroscopy that showed the absorption peak at 372 nm. The SEM analysis during screening revealed that Oscillatoria sp. synthesized smallest ZnO NPs (~40 nm) that were further optimized for their higher yield by altering reaction conditions (pH, temperature, reaction time, concentration of extract and metal precursor). Best conditions for ZnO NPs synthesis are (0.02 M zinc nitrate, 10 ml of extract volume, pH 8, at 80 °C for 3 h). The NPs were purified through calcination at 350°C and characterized by UV-Vis, FTIR, XRD, SEM-EDAX, TEM, Zeta potential and DLS analysis. The comparative analysis of purified biogenic ZnO NPs with commercial chemically synthesized ZnO NPs (CS), exhibited their superior nature as antioxidant and anti-bacterial agent against both gram-positive and gram-negative bacteria. Synergistic effects of biogenic ZnO NPs and streptomycin additionally favored for their future use as a potential biomedical agent.
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Microbial communities attached to surfaces are found in many environments including the soil. This chapter deals with the applications of developed biofilms as biofertilizers in crop production and their contribution to battle against... more
Microbial communities attached to surfaces are found in many environments including the soil. This chapter deals with the applications of developed biofilms as biofertilizers in crop production and their contribution to battle against microbial pathogens involved in plant diseases. It describes the formation of biofilm involving various processes including surface conditioning, microbial cell adsorption to conditioned surface, growth of bacteria, and formation of EPS that resulted in growth of biofilm. There are various factors responsible for the formation and growth of biofilm. It includes topography of surface, physicochemical properties of medium, hydrodynamics, horizontal gene transfer, and quorum sensing. Here are a summary of factors involved in the different stages of biofilm development: (i) initiation of biofilm formation, (ii) maturation of the biofilm, and (iii) regulation of the biofilm architectural structure. Some ecological advantage and relevance of biofilm can be listed, viz., defense, nutrient availability and metabolic cooperation, colonization, acquisition of new genetic traits, etc. At last, this chapter describes the molecular mechanism of biofilm formation and biocontrol.
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Nanoparticles (NPs) have gained importance in technological advances owing to their user friendly enhanced and efficient physical, chemical, and biological characteristics compared to their bulk counterparts. Biological synthesis of NPs... more
Nanoparticles (NPs) have gained importance in technological advances owing to their user friendly enhanced and efficient physical, chemical, and biological characteristics compared to their bulk counterparts. Biological synthesis of NPs by using a microorganism, enzymes, or plant extracts offers a greener and eco-friendly approach besides many advantages over physical or chemical approaches. This study reports the biosynthesis of silver nanoparticles (AgNPs) using Nostoc muscorum NCCU 442 aqueous extract as the reducing and capping agent for AgNPs synthesis. The synthesized nanoparticles were characterized by UV-VIS spectrum, SEM, EDS, TEM, AFM, DLS and XRD. Results showed distinguishing polycrystalline nature of synthesized AgNPs with surface plasmon significant band in the size range of 6-45nm with average 30 size nm. FT-IR study revealed the role of secondary metabolites present in aqueous extract for the synthesis of AgNPs. Biological activities of purified AgNPs as antioxidant and antibacterial potential showed the highest antibacterial activity against Staphylococcus aureus MTCC 902.
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Background: Poly-3-hydroxybutyrate (PHB) has attracted much consideration as biodegradable biocompatible polymer. This thermoplastic polymer has comparable material properties to polypropylene. Materials with more valuable properties may... more
Background: Poly-3-hydroxybutyrate (PHB) has attracted much consideration as biodegradable biocompatible polymer. This thermoplastic polymer has comparable material properties to polypropylene. Materials with more valuable properties may result from blending, a common practice in polymer science. Objective: In this paper, blends of PHB (extracted from cyanobacterium Nostoc muscorum NCCU- 442 with polyethylene glycol (PEG) were investigated for their thermal, tensile, hydrophilic and biodegradation properties. Methods: Blends were prepared in different proportions of PHB/PEG viz. 100/0, 98/2, 95/5, 90/10, 80/20, and 70/30 (wt %) using solvent casting technique. Morphological properties were investigated by using Scanning Electron Microscopy (SEM). Differential scanning calorimetry and thermogravimetric analysis were done for thermal properties determination whereas the mechanical and hydrophilic properties of the blends were studied by means of an automated material testing system an...
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Research Interests: Neuroscience, Biophysics, Materials Science, Chemistry, Molecular Biology, and 15 moreCatalysis, Photochemistry, Biotechnology, Nanoparticle, Ecology, Nanomaterials, Nanotechnology, Medicine, Multidisciplinary, Metal Nanoparticles, Biocompatibility, Photocatalysis, Photocatalytic, Langmuir, and Biogenic Silver Nanoparticles
This review represents systematic and integrated picture of pesticide exposure to plant and its effect on growth and metabolism. Decades ago, agrochemicals were introduced aiming at enhancing crop yields and protecting crops from pests.... more
This review represents systematic and integrated picture of pesticide exposure to plant and its effect on growth and metabolism. Decades ago, agrochemicals were introduced aiming at enhancing crop yields and protecting crops from pests. Due to adaptation and resistance developed by pests to chemicals, every year higher amounts and new chemical compounds are used to protect crops, causing undesired side effects and raising the costs of food production. Biological chemical free agriculture is gaining also more and more support but it is still not able to respond to the need for producing massive amounts of food. The use of agrochemicals, including pesticides, remains a common practice especially in tropical regions and South countries. Cheap compounds, such as DDT, HCH and Lindane, that are environmentally persistent, are today banned from agriculture use in developed countries, but remain popular in developing countries. As a consequence, persistent residues of these chemicals contam...
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Cyanobacterium Spirulina is in ever increasing demand internationally due to its high value bio-chemical constituents which find application in areas like health foods and therapeutics, especially for its high protein content. The... more
Cyanobacterium Spirulina is in ever increasing demand internationally due to its high value bio-chemical constituents which find application in areas like health foods and therapeutics, especially for its high protein content. The Spirulina protein is superior to practically all proteins including those from legumes, and is comparable to milk proteins for that matter. Moreover, interest in its phycocyanin, b-carotene, polyunsaturated acids (PUFA) and super oxide dismutase (SOD) contents has attracted the attention of researchers the world over towards protecting, promoting and preserving the production of this useful micro-organism. The present investigation deals with examining the impact of various physical stresses viz. intensity and photo-period of light, varying chromatic regimes, temperature, pH, etc., on the growth of Spirulina platensis-S5 to spell the appropriate conditions for raising the strain in laboratory. No earlier report of this kind is available, so far, to our kno...
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Research Interests: Biology, Cyanobacteria, Medicine, Multidisciplinary, Free Radical, and 15 moreAntioxidants, Insecticides, Aquatic Ecosystem, Environmental Concern, Catalase, Nitrogen, Detoxification, Degradation, Endosulfan, Bioremedation, Antioxidant enzyme, Ecosystem, Malondialdehyde, Ascorbate Peroxidase, and APX
Mishra, NP, Fatma, T. and Singhal, GS 1995. Developnent of antioxidative de-fense system of wheat seedlings in response to high light. - Physiol. Plant. 95: 77-82. Changes in the activities of enzymes involved in the detoxification of... more
Mishra, NP, Fatma, T. and Singhal, GS 1995. Developnent of antioxidative de-fense system of wheat seedlings in response to high light. - Physiol. Plant. 95: 77-82. Changes in the activities of enzymes involved in the detoxification of reactive oxygen species in wheat seedlings ( ...
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ABSTRACT
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ABSTRACT Adhesion to biomaterial is assumed to be a crucial step in the pathogenesis of foreign body infection. Slime producing Staphylococcus epidermidis and Staphylococcus aureus have emerged as a preeminent cause of nosocomial... more
ABSTRACT Adhesion to biomaterial is assumed to be a crucial step in the pathogenesis of foreign body infection. Slime producing Staphylococcus epidermidis and Staphylococcus aureus have emerged as a preeminent cause of nosocomial bacteremia and infections of prosthetic medical devices. We evaluated the time-dependent anti-adhesive effect of RBx 7644 (ranbezolid), vancomycin, linezolid and quinupristin/ dalfopristin on two isolates each of S. epidermidis and S. aureus. Linezolid and quinupristin/ dalfopristin showed inhibition only at supra-inhibitory concentrations (2 and 4X MIC) following 2 and 4 h delayed treatment, whereas RBx 7644 demonstrated significant activity against adhesion of staphylococcal cells that had been treated with 2 to 6 h delay. When vancomycin treatment was delayed by 4 to 6 h, even concentrations above the MIC were unable to prevent adherence. This study indicates that RBx 7644 has anti-adhesion potential and may emerge as an important antibiotic for prevention and treatment of device-related infections caused by staphylococci.
Research Interests: Biofilms, Chemotherapy, Medicine, Adhesion, Vancomycin, and 14 moreBiofilm, Surface, Plastics, Bacteria, Staphylococcus aureus, Staphylococcus epidermidis, Anti-Bacterial Agents, Time Factors, Microbial Sensitivity Tests, Bacterial Adhesion, Furans, Oxazolidinones, Acetamides, and Pharmacology and pharmaceutical sciences
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Research Interests: Microbiology, Medical Microbiology, Biology, Medicine, Population, and 15 moreBacteria, Laboratory, Phenotype, Laboratories, Antibiotics, Antimicrobial agents, Microbial Sensitivity Tests, Efflux Pumps, Agar, Sensitivity and Specificity, Area Under the Curve, Methicillin Resistant Staphylococcus Aureus, Doubling Time, Pharmacology and pharmaceutical sciences, and Minimum Inhibitory Concentration
algae isolates obtained from fresh and marine resources could be one of the richest sources of novel bioactive secondary metabolites expected to have pharmaceutical significance for new drug development. This study was conducted to... more
algae isolates obtained from fresh and marine resources could be one of the richest sources of novel bioactive secondary metabolites expected to have pharmaceutical significance for new drug development. This study was conducted to evaluate the antiangiogenic and antiproliferative activity of Chlorella pyrenoidosa in experimental models of angiogenesis and by MTT assay. lyophilized extract of C. pyrenoidosa was extracted using dichloromethane/methanol (2:1), concentrated and vacuum evaporated to obtain the dried extract. The crude extract was evaluated in the vascular endothelial growth factor (VEGF)-induced angiogenesis in in ovo chick chorioallantoic membrane assay (CAM) at various concentrations (n = 8) using thalidomide and normal saline as positive and untreated control groups, respectively. The crude extract was also subjected to the antiangiogenic activity in the silver nitrate/potassium nitrate cautery model of corneal neovascularization (CN) in rats where topical bevacizumab was used as a positive control. The vasculature was photographed and blood vessel density was quantified using Aphelion imaging software. The extract was also evaluated for its anti proliferative activity by microculture tetrazolium test (MTT) assay using HeLa cancer cell line (ATCC). VEGF increased the blood vessel density by 220% as compared to normal and thalidomide treatment decreased it to 67.2% in in ovo assay. In the in-vivo CN model, the mean neovascular density in the control group, the C. pyrenoidosa extract and bevacizumab group were found to be 100%, 59.02%, and 32.20%, respectively. The Chlorella pyrenoidosa extract negatively affected the viability of HeLa cells. An IC50 value of the extract was 570 μg/ml, respectively. a significant antiangiogenic activity was observed against VEGF-induced neovascularization and antiproliferative activity by MTT assay. In this study, it could be attributed that the activity may be due to the presence of secondary metabolites in the C. pyrenoidosa extract.
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Scytonemin is believed to protect a variety of organisms against the negative effects of ultraviolet radiation. Cyanobacteria have evolved different strategies to minimize the potential damage caused by solar ultraviolet radiation. This... more
Scytonemin is believed to protect a variety of organisms against the negative effects of ultraviolet radiation. Cyanobacteria have evolved different strategies to minimize the potential damage caused by solar ultraviolet radiation. This includes the synthesis of the UV-absorbing compound scytonemin, which acts as a sunscreen. During the present study scytonemin was found in 9 out of 19 studied cyanobacterial strains. Aulosira fertilissima showed the maximum amount of scytonemin. The effect of environmental factors, including temperature, light intensity, UV-light and salt was studied on scytonemin synthesis of A. fertilissima. A remarkable change in scytonemin synthesis was observed under salt stress and UV-light stress. Scytonemin increased under all stress conditions but it increased maximally under yellow-light stress.
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Illuminating the role of protein on the surface of cyanobacterial derived capped, decapped AgNPs and its biomedical application.
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Weeds are the worst category of agricultural pests as they compete with crops for water, nutrients, and light, grow faster than crops and eventually reduces the crop productivity thereby increasing the production cost. Herbicide has been... more
Weeds are the worst category of agricultural pests as they compete with crops for water, nutrients, and light, grow faster than crops and eventually reduces the crop productivity thereby increasing the production cost. Herbicide has been used as a management tool to control weeds, by modifying their physiological activities like reducing photosynthesis, increasing protease activity and free radicals etc. The application of non-selected herbicides kills not only the weeds but also non-target organisms including the main crop. Herbicides like paraquat have been used in rice fields but its toxic effects on other organisms is at par. Salicylic acid, a plant growth regulator, is known to regulate oxidative stress in plants subjected to unfavourable environmental conditions. Given this, the present study was designed to study the effect of salicylic acid in Microchaete sp. NCCU-342 exposed to paraquat. The results obtained demonstrated that the paraquat toxicity elevated MDA and H2O2 leve...
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The present study involves the green synthesis of platinum nanoparticles and their application as anticancer and antibacterial agents.
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Aldehyde-deformylating oxygenase (ADO) is an essential enzyme for production of long-chain alkanes as drop-in biofuels, which are compatible with existing fuel systems. The most active ADOs are present in mesophilic cyanobacteria,... more
Aldehyde-deformylating oxygenase (ADO) is an essential enzyme for production of long-chain alkanes as drop-in biofuels, which are compatible with existing fuel systems. The most active ADOs are present in mesophilic cyanobacteria, especially Given the potential applications of thermostable enzymes in biorefineries, here we generated a thermostable (Cts)-ADO based on a consensus of ADO sequences from several thermophilic cyanobacterial strains. Using an design pipeline and a metagenome library containing 41 hot-spring microbial communities, we created Cts-ADO. Cts-ADO displayed a 3.8-fold increase in pentadecane production on raising the temperature from 30°C to 42°C, whereas ADO from (Np-ADO) exhibited a 1.7-fold decline. 3D structure modeling and molecular dynamics simulations of Cts- and Np-ADO at different temperatures revealed differences between the two enzymes in residues clustered on exposed loops of these variants, which affected the conformation of helices involved in formi...
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Cyanobacteria has evolved the capacity to synthesize, mount up and metabolize scytonemin a photoprotective pigment as a part of an overall tactic to taper the unswerving and oblique destructive effects of environmental ultraviolet... more
Cyanobacteria has evolved the capacity to synthesize, mount up and metabolize scytonemin a photoprotective pigment as a part of an overall tactic to taper the unswerving and oblique destructive effects of environmental ultraviolet radiation (UVR) due to the deterioration of ozone layer attributable to the release of pollution containing the chemicals chlorine and bromine. Scytonemin is an indole phenolic pigment found in the sheath of many cyanobacteria having a unique dimeric structure, ecological importance and novel pharmaceutical activity have enthused substantial pursuit in its biosynthesis. This study includes the screening of scytonemin from 46 studied cyanobacterial strains out of which 23 showed the presence of scytonemin. Aulosira fertilissima showed the maximum scytonemin. The effect of environmental factors, including Light intensity, photoperiod, UV-light was studied on scytonemin synthesis of A. fertilissima. A remarkable change in scytonemin synthesis was observed und...
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Biologically active compounds with different modes of action, such as antiproliferative, antioxidant, antimicrotubule, have been isolated from algae and cyanobacteria. The present study was designed to evaluate antiangiogenic and... more
Biologically active compounds with different modes of action, such as antiproliferative, antioxidant, antimicrotubule, have been isolated from algae and cyanobacteria. The present study was designed to evaluate antiangiogenic and antiproliferative potential of dichloromethane and methanol (2:1) extracts of different cyanobacteria. Further fingerprinting of the activity possessing extracts were carried out using ESI-LC-MS/MS. Extracts (25, 50 and 100 microg) were screened in the vascular endothelial growth factor (VEGF) induced angiogenesis in inovo chick chorioallontoic membrane assay (CAM) at various concentrations using thalidomide and normal saline as positive and untreated control groups respectively. The extracts were also evaluated for their antiproliferative activity by MTT assay using HeLa cancer cell line. The results obtained from the various algal extracts did not show any significant antiangiogenic activity as compared to VEGF control. Oscillatoria sp. and Lyngbya offici...
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Adhesion to biomaterial is assumed to be a crucial step in the development of staphylococcal foreign body infections. Production of extracellular slime has major implications for the development and implementation of therapeutic... more
Adhesion to biomaterial is assumed to be a crucial step in the development of staphylococcal foreign body infections. Production of extracellular slime has major implications for the development and implementation of therapeutic strategies. The effect of extracted slime was investigated on the activity of vancomycin, teicoplanin, linezolid, quinupristin/dalfopristin, rifampicin and ranbezolid against 10 clinical and 4 ATCC staphylococcal isolates. The slime extract caused a 2- to 16-fold increase in the MICs of vancomycin and teicoplanin, with a shift in the MIC(90) from 2 to 32 (vancomycin) and 2 to 16 (teicoplanin), whereas the MICs of linezolid and quinupristin/dalfopristin were only moderately affected. In time-kill studies, a significant decrease in bacterial killing (>3 log(10) cfu/ml) was observed with vancomycin and teicoplanin (4 x MIC) after addition of slime (5 and 20 mg/ml), whereas the effect of killing by linezolid and quinupristin/dalfopristin was very modest. The ...
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In the present study, changes in velocity of cytoplasmic streaming in the giant internodal cells of Nitella for varying concentration of the pesticides, 2,4-D, dieldrin, malathion, methyl parathion and endosulfan, were measured. Marked... more
In the present study, changes in velocity of cytoplasmic streaming in the giant internodal cells of Nitella for varying concentration of the pesticides, 2,4-D, dieldrin, malathion, methyl parathion and endosulfan, were measured. Marked decrease in the velocity of cytoplasmic streaming was found at the concentrations of 0.01, 0.1, 1, 10 and 100mM. Dieldrin was the most toxic to all the pesticides investigated, followed by methyl parathion, endosulfan, malathion and 2,4-D. Threshold values for dieldrin, methylparathion, endosulfan, malathion and 2,4-D as indicated by the onset of decrease in the normal cytoplasmic streaming velocity were less than 6.25 x 10(-6), 2.5 x 10(-5), 5 x 10(-5), 5 x 10(-5) and 1.25 x 10(-5)M respectively. Cessation of streaming was noticed above 1mM in dieldrin and above 10mM when exposed to methylparathion and endosulfan. Cessation of streaming was not seen up to 100mM concentration of 2,4-D and malathion.