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Sample records for bacteria purification properties

  1. Water Purification Using Functionalized Cellulosic Fibers with Nonleaching Bacteria Adsorbing Properties.

    Science.gov (United States)

    Ottenhall, Anna; Illergård, Josefin; Ek, Monica

    2017-07-05

    Portable purification systems are easy ways to obtain clean drinking water when there is no large-scale water treatment available. In this study, the potential to purify water using bacteria adsorbing cellulosic fibers, functionalized with polyelectrolytes according to the layer-by-layer method, is investigated. The adsorbed polyelectrolytes create a positive charge on the fiber surface that physically attracts and bonds with bacteria. Three types of cellulosic materials have been modified and tested for the bacterial removal capacity in water. The time, material-water ratio and bacterial concentration dependence, as well as the bacterial removal capacity in water from natural sources, have been evaluated. Freely dispersed bacteria adsorbing cellulosic fibers can remove greater than 99.9% of Escherichia coli from nonturbid water, with the most notable reduction occurring within the first hour. A filtering approach using modified cellulosic fibers is desirable for purification of natural water. An initial filtration test showed that polyelectrolyte multilayer modified cellulosic fibers can remove greater than 99% of bacteria from natural water. The bacteria adsorbing cellulosic fibers do not leach any biocides, and it is an environmentally sustainable and cheap option for disposable water purification devices.

  2. Separation, Purification and Identification of Bacteria

    African Journals Online (AJOL)

    user

    2011-05-16

    May 16, 2011 ... biochemical characteristics of the bacteria (Joseph et al., 2001). The common standard strains such as .... Berger's Manual of. Determinative Bacteriology. The Williams and Wilkins CO., Baltimore. (USA). Bruce E, Susan (1988). Recent advances in the development of an improved human anthrax vaccine.

  3. Immunomodulatory properties of probiotic bacteria

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria...... with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when cultured with blood DC......, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the intestinal microbiota...

  4. Purification Techniques of Bacteriocins from Lactic Acid Bacteria and Other Gram-Positive Bacteria

    Science.gov (United States)

    Saavedra, Lucila; Sesma, Fernando

    The search for new antimicrobial peptides produced by lactic acid ­bacteria and other Gram-positive microorganisms has become an interesting field of research in the past decades. The fact that bacteriocins are active against numerous foodborne and human pathogens, are produced by generally regarded as safe (GRAS) microorganisms, and are readily degraded by proteolytic host systems makes them attractive candidates for biotechnological applications. However, before suggesting or choosing a new bacteriocin for future technology developments, it is necessary to elucidate its biochemical structure and its mode of action, which may be carried out once the bacteriocin is purified to homogeneity. This chapter focuses on describing the main strategies used for the purification of numerous bacteriocins.

  5. Isolation, purification and identification of bacteria from the shoes ...

    African Journals Online (AJOL)

    13 strains of bacteria were isolated from 12 shoes that were worn by children aged 6 to 12 for more than half a year. Through morphological observation, physiological and biochemical measurements, as well as 16SrRNA sequence analysis, the bacteria were identified as follows: Bacillus licheniformis, Bacillus subtilis (5 ...

  6. Antioxidant Properties of Probiotic Bacteria.

    Science.gov (United States)

    Wang, Yang; Wu, Yanping; Wang, Yuanyuan; Xu, Han; Mei, Xiaoqiang; Yu, Dongyou; Wang, Yibing; Li, Weifen

    2017-05-19

    Oxidative stress defines a condition in which the prooxidant-antioxidant balance in the cell is disturbed, resulting in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' viability. Probiotics have been known for many beneficial health effects, and the consumption of probiotics alone or in food shows that strain-specific probiotics can present antioxidant activity and reduce damages caused by oxidation. However, the oxidation-resistant ability of probiotics, especially the underling mechanisms, is not properly understood. In this view, there is interest to figure out the antioxidant property of probiotics and summarize the mode of action of probiotic bacteria in antioxidation. Therefore, in the present paper, the antioxidant mechanisms of probiotics have been reviewed in terms of their ability to improve the antioxidant system and their ability to decrease radical generation. Since in recent years, oxidative stress has been associated with an altered gut microbiota, the effects of probiotics on intestinal flora composition are also elaborated.

  7. Purification of methanol dehydrogenase from mouth methylotrophic bacteria of tropical region

    Directory of Open Access Journals (Sweden)

    Waturangi, D.

    2011-01-01

    Full Text Available Aims: Purification of methanol dehydrogenase (MDH from methylotrophic bacteria was conducted to obtain pure enzyme for further research and industrial applications due to the enzyme’s unique activity that catalyzes oxidation of methanol as an important carbon source in methylotrophic bacteria.Methodology and Results: The enzyme was screened from methylotrophic bacteria isolated from human mouth. Purification of this enzyme was conducted using ammonium sulphate precipitation followed by cation exchange chromatography. Two types of media were used to produce the enzymes: luria broth and standard mineral salts media (MSM. MSM produced MDH with higher specific activity than LB. Specific activity was also increased along with the purification steps. Application of ammonium sulphate increased the purity of enzyme and was more effective for the enzyme produced in LB. Using sepharose increased the enzyme activity 10 -57 folds.Conclusion, significant and impact of this study: With this, ammonium sulphate precipitation coupled with single cation exchange chromatographic system has been proved to provide sufficient purified of methanol dehydrogenase from methylotrophic bacteria origin of human mouth with high specific activity for further application.

  8. Purification and properties of cowpea mosaic virus RNA replicase

    NARCIS (Netherlands)

    Zabel, P.

    1978-01-01

    This thesis concerns the partial purification and properties of an RNA-dependent RNA polymerase (RNA replicase) produced upon infection of Vigna unguiculata plants with Cowpea Mosaic Virus (CPMV). The enzyme is believed to be coded, at least in part, by the virus genome and to

  9. Purification and Some Properties of a Thermostable α-Amylase ...

    African Journals Online (AJOL)

    This work reports the isolation, purification and some properties of a thermostable α-amylase producing Bacillus subtilis isolated from the soil. Soil samples were collected and screened for thermophilic bacterial strains with amylase activity and to examine the amylase heat tolerance potentiality. The isolate was Gram ...

  10. Purification and properties of Rhizobial DehL expressed in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Full Length Research Paper. Purification and properties of Rhizobial DehL expressed in Escherichia coli. Fahrul Huyop1*, Nooraini Abdul Rashid1, Roswanira A. B. Wahab2 and Ronald A. Cooper3. 1Industrial Biotechnology Department, University Technology Malaysia, 81310 Skudai, Johor, Malaysia.

  11. Production and Purification of Recombinant SUMOylated Proteins Using Engineered Bacteria.

    Science.gov (United States)

    Brockly, Frédérique; Piechaczyk, Marc; Bossis, Guillaume

    2016-01-01

    SUMO is a ubiquitin-like protein that is covalently conjugated to numerous cellular proteins to modify their function and fate. Although large progresses have been made in the identification of SUMOylated proteins, the molecular consequences of their SUMOylation are generally unknown. This is, most often, due to the low abundance of SUMOylated proteins in the cell, usually less than 1 % of a given protein being modified at steady state. To gain insights into the role of specific SUMOylation targets, SUMO conjugation can be reconstituted in vitro using purified proteins. However, for most substrates, the efficiency of in vitro SUMOylation is too low to obtain sufficient amounts of their SUMOylated forms for biochemical studies. Here, we describe a detailed protocol to purify large amounts of recombinant SUMOylated proteins using bacteria modified to express His-tagged SUMO as well as the SUMO-activating and -conjugating enzymes.

  12. Extraction, isolation and purification of exopolysaccharide from lactic acid bacteria using ethanol precipitation method

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2016-09-01

    Full Text Available Lactic acid bacteria are classified ‘Generally Recognized As Safe’ (GRAS with most effective potential to divert significant amount of fermentable sugars towards the biosynthesis of functional exopolysaccharide. Exopolysaccharides from lactic acid bacteria are receiving a renewed interest due to the claims of human health benefits, such as modulation of immune response system and more importantly in food and pharma industries as a texturizer, viscosifer, emulsifier and syneresis-lowering agent. Its purification methodology involves: a Extraction of cell-free supernatant from lactic acid bacteria; b Denature of protein using trichloroacetic acid; c Ethanol precipitation; d Dialysis; and e Freeze drying. However, depending on nature of research, compounds can be further purified using scanning electron microscopy (SEM, infrared spectrum (IR; and nuclear magnetic resonance (NMR spectral analyses.

  13. Reverse osmosis membrane of high urea rejection properties. [water purification

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T. J. (Inventor)

    1980-01-01

    Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source. A polymeric membrane is formed by depositing a polymer of the unsaturated monomer from the plasma onto a substrate, so that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.

  14. Partial purification and some physicochemical properties of ...

    African Journals Online (AJOL)

    It thus produces α-amylase which is thermostable, a property which could be exploited for industrial purposes where hydrolysis of starch and other complex carbohydrates are required. Keywords: Cassava, α-amylase, starch hydrolysis, Aspergillus species, industrial application. African Journal of Biotechnology, Vol 13(52) ...

  15. Escherichia coli photoreactivating enzyme: purification and properties

    International Nuclear Information System (INIS)

    Snapka, R.M.; Sutherland, B.M.

    1980-01-01

    Researchers have purified large quantities of Escherichia coli photoreactivating enzyme to apparent homogeneity and have studied its physical and chemical properties. The enzyme has a molecular weight of 36,800 and a S/sub 20,w/ 0 of 3.72 S. Amino acid analysis revealed an apparent absence of tryptophan, a low content of aromatic residues, and the presence of no unusual amino acids. The N terminus is arginine. The purified enzyme contained up to 13% carbohydrate by weight. The carbohydrate was composed of mannose, galactose, glucose, and N-acetylglucosamine. The enzyme is also associated with RNA containing uracil, adenine, guanine, and cytosine with no unusual bases detected

  16. Exploiting interfacial water properties for desalination and purification applications.

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongwu (Los Alamos National Laboratory, Los Alamos, NM); Varma, Sameer; Nyman, May Devan; Alam, Todd Michael; Thuermer, Konrad; Holland, Gregory P.; Leung, Kevin; Liu, Nanguo (University of New Mexico Albuquerque, NM); Xomeritakis, George K. (University of New Mexico Albuquerque, NM); Frankamp, Benjamin L.; Siepmann, J. Ilja (University of Minnesota, Minneapolis, MN); Cygan, Randall Timothy; Hartl, Monika A. (Los Alamos National Laboratory, Los Alamos, NM); Travesset, Alex (Iowa State University, Ames, IA); Anderson, Joshua A. (Iowa State University, Ames, IA); Huber, Dale L.; Kissel, David J. (University of New Mexico Albuquerque, NM); Bunker, Bruce Conrad; Lorenz, Christian Douglas; Major, Ryan C. (University of Minnesota, Minneapolis, MN); McGrath, Matthew J. (University of Minnesota, Minneapolis, MN); Farrow, Darcie; Cecchi, Joseph L. (University of New Mexico Albuquerque, NM); van Swol, Frank B.; Singh, Seema; Rempe, Susan B.; Brinker, C. Jeffrey; Clawson, Jacalyn S.; Feibelman, Peter Julian; Houston, Jack E.; Crozier, Paul Stewart; Criscenti, Louise Jacqueline; Chen, Zhu (University of New Mexico Albuquerque, NM); Zhu, Xiaoyang (University of Minnesota, Minneapolis, MN); Dunphy, Darren Robert (University of New Mexico Albuquerque, NM); Orendorff, Christopher J.; Pless, Jason D.; Daemen, Luke L. (Los Alamos National Laboratory, Los Alamos, NM); Gerung, Henry (University of New Mexico Albuquerque, NM); Ockwig, Nathan W.; Nenoff, Tina Maria; Jiang, Ying-Bing; Stevens, Mark Jackson

    2008-09-01

    A molecular-scale interpretation of interfacial processes is often downplayed in the analysis of traditional water treatment methods. However, such an approach is critical for the development of enhanced performance in traditional desalination and water treatments. Water confined between surfaces, within channels, or in pores is ubiquitous in technology and nature. Its physical and chemical properties in such environments are unpredictably different from bulk water. As a result, advances in water desalination and purification methods may be accomplished through an improved analysis of water behavior in these challenging environments using state-of-the-art microscopy, spectroscopy, experimental, and computational methods.

  17. Membranes with Surface-Enhanced Antifouling Properties for Water Purification

    Science.gov (United States)

    Shahkaramipour, Nima; Tran, Thien N.; Ramanan, Sankara; Lin, Haiqing

    2017-01-01

    Membrane technology has emerged as an attractive approach for water purification, while mitigation of fouling is key to lower membrane operating costs. This article reviews various materials with antifouling properties that can be coated or grafted onto the membrane surface to improve the antifouling properties of the membranes and thus, retain high water permeance. These materials can be separated into three categories, hydrophilic materials, such as poly(ethylene glycol), polydopamine and zwitterions, hydrophobic materials, such as fluoropolymers, and amphiphilic materials. The states of water in these materials and the mechanisms for the antifouling properties are discussed. The corresponding approaches to coat or graft these materials on the membrane surface are reviewed, and the materials with promising performance are highlighted. PMID:28273869

  18. Current state of purification, isolation and analysis of bacteriocins produced by lactic acid bacteria.

    Science.gov (United States)

    Kaškonienė, Vilma; Stankevičius, Mantas; Bimbiraitė-Survilienė, Kristina; Naujokaitytė, Gintarė; Šernienė, Loreta; Mulkytė, Kristina; Malakauskas, Mindaugas; Maruška, Audrius

    2017-02-01

    The scientific interest for the search of natural means of microbial inhibitors has not faded for several years. A search of natural antibiotics, so-called bacteriocins which are produced by lactic acid bacteria (LAB), gains a huge attention of the scientists in the last century, in order to reduce the usage of synthetic food additives. Pure bacteriocins with wide spectra of antibacterial activity are promising among the natural biopreservatives. The usage of bacteriocin(s) producing LAB as starter culture for the fermentation of some food products, in order to increase their shelf-life, when synthetic preservatives are not allowable, is also possible. There are a lot of studies focusing on the isolation of new bacteriocins from traditional fermented food, dairy products and other foods or sometimes even from unusual non-food matrices. Bacteriocins producing bacteria have been isolated from different sources with the different antibacterial activity against food-borne microorganisms. This review covers the classification of bacteriocins, diversity of sources of bacteriocin(s) producing LAB, antibacterial spectra of isolated bacteriocins and analytical methods for the bacteriocin purification and analysis within the last 15 years.

  19. Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system

    Directory of Open Access Journals (Sweden)

    Penna Thereza CV

    2006-08-01

    Full Text Available Abstract Background Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value necessary to inactivate 90% of the initial bioburden (decimal reduction time was experimentally determined. Methods Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were called in house (wild bacteria. Pseudomonas diminuta ATCC 11568, Pseudomonas alcaligenes INCQS , Pseudomonas aeruginosa ATCC 15442, Pseudomonas fluorescens ATCC 3178, Pseudomonas picketti ATCC 5031, Bacillus subtilis ATCC 937 and Escherichia coli ATCC 25922 were used as 'standard' bacteria to evaluate resistance at 25°C against either 0.5% citric acid, 0.5% hydrochloric acid, 70% ethanol, 0.5% sodium bisulfite, 0.4% sodium hydroxide, 0.5% sodium hypochlorite, or a mixture of 2.2% hydrogen peroxide (H2O2 and 0.45% peracetic acid. Results The efficacy of the sanitizers varied with concentration and contact time to reduce decimal logarithmic (log10 population (n cycles. To kill 90% of the initial population (or one log10 cycle, the necessary time (D-value was for P. aeruginosa into: (i 0.5% citric acid, D = 3.8 min; (ii 0.5% hydrochloric acid, D = 6.9 min; (iii 70% ethanol, D = 9.7 min; (iv 0.5% sodium bisulfite, D = 5.3 min; (v 0.4% sodium hydroxide, D = 14.2 min; (vi 0.5% sodium

  20. Purification and characterization of trypsin produced by gut bacteria from Anticarsia gemmatalis.

    Science.gov (United States)

    Pilon, Franciny Martins; Silva, Camila da Rocha; Visôtto, Liliane Evangelista; Barros, Rafael de Almeida; da Silva Júnior, Neilier Rodrigues; Campos, Wellington Garcia; de Almeida Oliveira, Maria Goreti

    2017-10-01

    Purification of active trypsin in the digestive process of insects is essential for the development of potent protease inhibitors (PIs) as an emerging pest control technology and research into insect adaptations to dietary PIs. An important aspect is the presence of proteolytic microorganisms, which contribute to host nutrition. Here, we purified trypsins produced by bacteria Bacillus cereus, Enterococcus mundtii, Enterococcus gallinarum, and Staphylococcus xylosus isolated from the midgut of Anticarsia gemmatalis. The trypsins had a molecular mass of approximately 25 kDa. The enzymes showed increased activity at 40°C, and they were active at pH values 7.5-10. Aprotinin, bis-benzamidine, and soybean Kunitz inhibitor (SKTI) significantly inhibited trypsin activity. The l-1-tosyl-amido-2-phenylethylchloromethyl ketone (TPCK), pepstatin A, E-64, ethylenediamine tetraacetic acid, and calcium ions did not affect the enzyme activity at the concentrations tested. We infer the purified trypsins do not require calcium ions, by which they differ from the trypsins of other microorganisms and the soluble and insoluble trypsins characterized from A. gemmatalis. These data suggest the existence of different isoforms of trypsin in the velvetbean caterpillar midguts. © 2017 Wiley Periodicals, Inc.

  1. [Purification and properties of NAG A from human kidney].

    Science.gov (United States)

    Yoshida, K

    1992-08-01

    In the present paper, we have reported the purification procedures of N-acetyl-beta, D-glucosaminidase (NAG) A from human renal tissue as well as the enzymatic properties of NAG A. NAG A was purified to homogeneity by gel filtration methods using Sephacry S-400 and S-200, followed by affinity chromatography with TSK DEAE 5-PW. The final activity of the enzyme was 1001 U/ml protein which was 506.6-fold that of the crude extract (supernatant of 20,000 x G of the homogenate). The molecular weight of NAG A was 140 kDa, consisting of two subunits of 30 kDa and 57 kDa. The isoelectric point of the enzyme was 5.60. The optimal pH of the enzyme was between 4.7 and 4.9. The Km value of the enzyme for sodio-m-cresol sulfophtaleinyl-N-acetyl-beta, D-glucosaminide was found 0.177 x 10(-3) mol/l. Lectin affinity chromatographies using concanavalin A and wheat germagglutinin have demonstrated that major sugar-chains of the enzyme were the high mannose type and hybrid type with a fucose residue, and that a small amount of the complex type was contained.

  2. Identification of bacteria in drinking and purified water during the monitoring of a typical water purification system

    Directory of Open Access Journals (Sweden)

    Mazzola Priscila

    2002-08-01

    Full Text Available Abstract Background A typical purification system that provides purified water which meets ionic and organic chemical standards, must be protected from microbial proliferation to minimize cross-contamination for use in cleaning and preparations in pharmaceutical industries and in health environments. Methodology Samples of water were taken directly from the public distribution water tank at twelve different stages of a typical purification system were analyzed for the identification of isolated bacteria. Two miniature kits were used: (i identification system (api 20 NE, Bio-Mérieux for non-enteric and non-fermenting gram-negative rods; and (ii identification system (BBL crystal, Becton and Dickson for enteric and non-fermenting gram-negative rods. The efficiency of the chemical sanitizers used in the stages of the system, over the isolated and identified bacteria in the sampling water, was evaluated by the minimum inhibitory concentration (MIC method. Results The 78 isolated colonies were identified as the following bacteria genera: Pseudomonas, Flavobacterium and Acinetobacter. According to the miniature kits used in the identification, there was a prevalence of isolation of P. aeruginosa 32.05%, P. picketti (Ralstonia picketti 23.08%, P. vesiculares 12.82%,P. diminuta 11.54%, F. aureum 6.42%, P. fluorescens 5.13%, A. lwoffi 2.56%, P. putida 2.56%, P. alcaligenes 1.28%, P. paucimobilis 1.28%, and F. multivorum 1.28%. Conclusions We found that research was required for the identification of gram-negative non-fermenting bacteria, which were isolated from drinking water and water purification systems, since Pseudomonas genera represents opportunistic pathogens which disperse and adhere easily to surfaces, forming a biofilm which interferes with the cleaning and disinfection procedures in hospital and industrial environments.

  3. [Unique properties of highly radioresistant bacteria].

    Science.gov (United States)

    Romanovskaia, V A; Rokitko, P V; Malashenko, Iu R

    2000-01-01

    In connection with the Chernobyl Nuclear Power Plant (ChNPP) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. The analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. The extreme radioresistant bacteria are represented by the Deinococcus species, which form a group phylogenetically close to the line Thermus-Meiothermus. Other radioresistant bacteria are the representatives of the genera Rubrobacter, Methylobacterium, Kocuria, Bacillus and some archebacteria. Data on natural habitats, of radioresistant bacteria are not numerous. In a number of cases it is difficult to distinguish their natural habitats, as they were isolated from the samples which were previously exposed to X-ray or gamma-irradiation, or from the ecosystems with the naturally raised radioactivity. To understand the strategy of survival of radioresistant bacteria, we briefly reviewed the mechanism of action of various species of radiation on cells and macromolecules; physiological signs of the cell damage caused by radiation; mechanisms eliminating (repairing) these damages. More details on mechanisms of the DNA repair in D. radiodurans are described. The extreme resistance of D. radiodurans to the DNA damaging factors is defined by 1) repair mechanisms which fundamentally differ from those in other procaryotes; 2) ability to increase the efficiency of a standard set of the DNA repairing proteins. Literary and own data on the effect of radiation on survival of various groups of bacteria in natural ecosystems are summarized. The ecological consequences of the ChNPP accident for soil bacteria in this region were estimated. The reduction of the number of soil bacteria and recession of microbial diversity under the effect of

  4. Anti-fungal properties of chitinolytic dune soil bacteria

    NARCIS (Netherlands)

    De Boer, W.; Klein Gunnewiek, P.J.A.; Lafeber, P.; Janse, J.H.; Spit, B.E.; Woldendorp, J.W.

    1998-01-01

    Anti-fungal properties of chitinolytic soil bacteria may enable them to compete successfully for chitin with fungi. Additionally, the production of chitinase may be part of a lytic system that enables the bacteria to use living hyphae rather than chitin as the actual growth substrate, since chitin

  5. Technologically important properties of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Technologically important properties of lactic acid bacteria isolated from raw milk of three breeds of Algerian dromedary ( Camelus dromedarius ) ... isolated from Algerian dromedary milks that showed potentially important properties suggest that they are good candidate for camels milk processing or other dairy fermentation ...

  6. Visualization of coupled protein folding and binding in bacteria and purification of the heterodimeric complex

    Science.gov (United States)

    Wang, Haoyong; Chong, Shaorong

    2003-01-01

    During overexpression of recombinant proteins in Escherichia coli, misfolded proteins often aggregate and form inclusion bodies. If an aggregation-prone recombinant protein is fused upstream (as an N-terminal fusion) to GFP, aggregation of the recombinant protein domain also leads to misfolding of the downstream GFP domain, resulting in a decrease or loss of fluorescence. We investigated whether the GFP domain could fold correctly if aggregation of the upstream protein domain was prevented in vivo by a coupled protein folding and binding interaction. Such interaction has been previously shown to occur between the E. coli integration host factors and , and between the domains of the general transcriptional coactivator cAMP response element binding protein (CREB)-binding protein and the activator for thyroid hormone and retinoid receptors. In this study, fusion of integration host factor or the CREB-binding protein domain upstream to GFP resulted in aggregation of the fusion protein. Coexpression of their respective partners, on the other hand, allowed soluble expression of the fusion protein and a dramatic increase in fluorescence. The study demonstrated that coupled protein folding and binding could be correlated to GFP fluorescence. A modified miniintein containing an affinity tag was inserted between the upstream protein domain and GFP to allow rapid purification and identification of the heterodimeric complex. The GFP coexpression fusion system may be used to identify novel protein-protein interactions that involve coupled folding and binding or protein partners that can solubilize aggregation-prone recombinant proteins.

  7. Air purification by cementitious materials : Evaluation of air purifying properties

    NARCIS (Netherlands)

    Hüsken, G.; Brouwers, H.J.H.; Al-Mattarneh, H.; Mustapha, K.N.; Nuruddin, M.F.

    2008-01-01

    This paper addresses the evaluation of the photocatalytic properties of concrete containing titanium dioxide (TiO2). Here, the assessment of the air purifying abilities of the hardened concrete regarding the degradation of nitric oxide (NO) is of major interest. A setup for measuring the performance

  8. Purification and some properties of glucose isomerase from Bacillus ...

    African Journals Online (AJOL)

    The objective of this study is to produce and purify glucose isomerase (GI) from Bacillus megaterium and to determine some of its properties. Soil sample was collected from cassava starch processing site and used immediately for bacterial isolation. Selected isolate produced the best GI activity in a preliminary test.

  9. Analysis of some functional properties of acetic acid bacteria ...

    African Journals Online (AJOL)

    SARAH

    2014-03-31

    Mar 31, 2014 ... Analysis of some functional properties of acetic acid bacteria involved in Ivorian cocoa fermentation. Wilfried YAO, Honoré G. OUATTARA, Bernadette GOUALIE, Souleymane SOUMAHORO, Sébastien. NIAMKE. Laboratoire de Biotechnologies, UFR Biosciences, Université Félix HOUPHOUET-BOIGNY ...

  10. Biochemical and functional properties of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Objective: Fermentation is an important step in the post-harvest processing of cocoa beans. The quality of beans and chocolate depends strongly on the type and characteristics of microbial strains involved in the fermentation. This study investigates some functional properties of lactic acid bacteria (LAB), involved in Côte ...

  11. Analysis of some functional properties of acetic acid bacteria ...

    African Journals Online (AJOL)

    Objective: To investigate some functional properties of acetic acid bacteria (AAB), involved in Côte d'Ivoire cocoa fermentation. Methods and results: Six day heap fermentation on banana leaves was conducted at farm level and AAB growth was monitored during this process at 24 h interval by numeration on plate agar.

  12. Purification and biochemical characterization of a cold-active lipase from Antarctic sea ice bacteria Pseudoalteromonas sp. NJ 70.

    Science.gov (United States)

    Wang, Quanfu; Hou, Yanhua; Ding, Yu; Yan, Peisheng

    2012-09-01

    An extracellular cold-active lipase from Antarctic sea ice bacteria Pseudoalteromonas sp. NJ 70 was purified and characterized. The overall purification based on lipase activity was 27.5-fold with a yield of 25.4 %. The purified lipase showed as a single band on SDS-PAGE with an apparent molecular weight of 37 kDa. The optimum temperature and pH were 35 °C and 7.0, respectively. The lipase activity was enhanced by Ca(2+) and Mg(2+), while was partially inhibited by other metals such as Cu(2+), Zn(2+), Ba(2+), Pb(2+), Fe(2+) and Mn(2+). The lipase had high tolerance to a wide range of NaCl concentrations (0-2 M NaCl). It exhibited high levels of activity in the presence of DTT, Thiourea, H(2)O(2) as well as in the presence of various detergents such as Span 60, Tween-80, Triton X-100. In addition, the lipase showed a preference for long-chain p-nitrophenyl esters (C(12)-C(18)). These results indicated that this lipase could be a novel cold-active lipase.

  13. Isolation and purification of wheat germ agglutinin and analysis of its properties

    Science.gov (United States)

    Wang, Han

    2017-12-01

    In this paper, the wheat germ agglutinin was isolated and purified by affinity chromatography of chicken ovomucoid as ligand. The physicochemical properties were analyzed. The chicken ovomucoid was isolated from egg white and conjugated to affinity chromatography column agarose gel to prepare affinity adsorbent. The crude extract of wheat germ was freezedried by affinity chromatography. The physicochemical properties were analyzed by SDSpolyacrylamide gel electrophoresis and isoelectric focusing electrophoresis. And the relative molecular mass and isoelectric point of wheat germ agglutinin were obtained, and the high efficiency of purification of wheat germ agglutinin was proved by affinity chromatography.

  14. Ion exchange resins for water purification : properties and characterisation

    International Nuclear Information System (INIS)

    Gokhale, A.S.; Mathur, P.K.; Venkateswarlu, K.S.

    1987-01-01

    The report is divided into three sections. The first section contains a general introduction to ion exchange resins used in various processes, the second section describes characteristic properties of the polymer materials and the inter relation between them. This will, in turn, be useful to interpret the data obtained from the various tests carried out on the resins in the laboratory. In the third section of the report, are given the details of each method used for a particular test to be carried out on a routine basis. Each method describes the principle involved, the reagents and apparatus used in the experiment, the actual procedure and calculations and recording of the data. 3 refs. (author)

  15. Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

    International Nuclear Information System (INIS)

    Janssen, Albert J.H.; Lens, Piet N.L.; Stams, Alfons J.M.; Plugge, Caroline M.; Sorokin, Dimitri Y.; Muyzer, Gerard; Dijkman, Henk; Van Zessen, Erik; Luimes, Peter; Buisman, Cees J.N.

    2009-01-01

    In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual COD organic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH 4 (80-90 vol.%), CO 2 (10-20 vol.%) and H 2 S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H 2 S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass

  16. Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, Albert J.H. [Sub-department of Environmental Technology, Wageningen University, Wageningen (Netherlands); Shell Global Solutions Int. B.V., Amsterdam (Netherlands)], E-mail: albert.janssen@wur.nl; Lens, Piet N.L. [Sub-department of Environmental Technology, Wageningen University, Wageningen (Netherlands); Stams, Alfons J.M.; Plugge, Caroline M. [Laboratory of Microbiology, Wageningen University, Wageningen (Netherlands); Sorokin, Dimitri Y. [Department of Biotechnology, Delft (Netherlands); Institute of Microbiology, Russian Academy of Science, Moscow (Russian Federation); Muyzer, Gerard [Department of Biotechnology, Delft (Netherlands); Dijkman, Henk; Van Zessen, Erik [Paques B.V., Balk (Netherlands); Luimes, Peter [Industriewater Eerbeek B.V. Eerbeek (Netherlands); Buisman, Cees J.N. [Sub-department of Environmental Technology, Wageningen University, Wageningen (Netherlands)

    2009-02-01

    In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual COD{sub organic} and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH{sub 4} (80-90 vol.%), CO{sub 2} (10-20 vol.%) and H{sub 2}S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H{sub 2}S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass.

  17. Surface properties of SAR11 bacteria facilitate grazing avoidance.

    Science.gov (United States)

    Dadon-Pilosof, Ayelet; Conley, Keats R; Jacobi, Yuval; Haber, Markus; Lombard, Fabien; Sutherland, Kelly R; Steindler, Laura; Tikochinski, Yaron; Richter, Michael; Glöckner, Frank Oliver; Suzuki, Marcelino T; West, Nyree J; Genin, Amatzia; Yahel, Gitai

    2017-12-01

    Oceanic ecosystems are dominated by minute microorganisms that play a major role in food webs and biogeochemical cycles 1 . Many microorganisms thrive in the dilute environment due to their capacity to locate, attach to, and use patches of nutrients and organic matter 2,3 . We propose that some free-living planktonic bacteria have traded their ability to stick to nutrient-rich organic particles for a non-stick cell surface that helps them evade predation by mucous filter feeders. We used a combination of in situ sampling techniques and next-generation sequencing to study the biological filtration of microorganisms at the phylotype level. Our data indicate that some marine bacteria, most notably the highly abundant Pelagibacter ubique and most other members of the SAR 11 clade of the Alphaproteobacteria, can evade filtration by slipping through the mucous nets of both pelagic and benthic tunicates. While 0.3 µm polystyrene beads and other similarly-sized bacteria were efficiently filtered, SAR11 members were not captured. Reversed-phase chromatography revealed that most SAR11 bacteria have a much less hydrophobic cell surface than that of other planktonic bacteria. Our data call for a reconsideration of the role of surface properties in biological filtration and predator-prey interactions in aquatic systems.

  18. Relative Effectiveness of Water Hyacinth, Bacteria and Fungi in ...

    African Journals Online (AJOL)

    phytoremedian), bacteria and fungi (bioremedians) used for the purification of domestic sewage was carried out using Completely Randomised Design (CRD) replicated three times. Physical, bacteriological and chemical properties of domestic sewage ...

  19. Purification, characterization of phytase enzyme from Lactobacillus ...

    African Journals Online (AJOL)

    Purification, characterization of phytase enzyme from Lactobacillus plantarum bacteria and determination of its kinetic properties. ... Many of the cereal grains, legumes and oilseeds store phosphorus in phytate form. Phytases can be produced by plants, animals and microorganisms. However, the ones with microbial origin ...

  20. Probiotic properties of lactic acid bacteria isolated from human milk.

    Science.gov (United States)

    Reis, N A; Saraiva, M A F; Duarte, E A A; de Carvalho, E A; Vieira, B B; Evangelista-Barreto, N S

    2016-09-01

    The objective of this study was to identify and characterize lactic acid bacteria isolated from human milk, with an emphasis on their probiotic properties. The strains were tested for their ability to inhibit growth of Enterococcus faecalis, Salmonella enterica subsp. enterica serotype Enteritidis, Listeria monocytogenes, Staphylococcus aureus and Escherichia coli, as well as for susceptibility to antimicrobial agents and for acid pH and bile salt tolerance. Gram-positive and catalase-negative were selected and identified as Enterococcus (83·3%) after sequencing the 16S rDNA gene. All the isolates inhibited growth of Ent. faecalis and S. serotype Enteritidis, 97% inhibited growth of L. monocytogenes and Staph. aureus and 78·8% inhibited growth of E. coli. Most of the isolates were resistant to gentamicin (50%) and vancomycin (47%). Twelve isolates grew when subjected to pH 3·0 and 0·1% bile salts. At lower pH (2·5-2·0), Ent. faecalis F1 and Weissella confusa F8 were more efficient. It was possible to isolate from human milk the lactic acid bacteria with potential for use as probiotics. Lactic acid bacteria isolated of nursing mothers have probiotic properties. © 2016 The Society for Applied Microbiology.

  1. [Evaluation of biocidal properties of silver nanoparticles against cariogenic bacteria].

    Science.gov (United States)

    Pokrowiecki, Rafal; Zareba, Tomasz; Mielczarek, Agnieszka; Opalińska, Agnieszka; Wojnarowicz, Jacek; Majkowski, Marcin; Lojkowski, Witold; Tyski, Stefan

    2013-01-01

    Antimicrobial properties of silver nanoparticles (SNP's) have been recentl well evaluated, and now are being considered as excellent candidates for therapeutic purposes. It is confirmed, that various solutions of colloidal SNP's possess significant antibacterial properties against such species as: Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa even at low concentrations, although there have been so far only a few researches evaluating antimicrobial activity of SNP's against cariogenic bacteria: Streptococcus mutans, Streptococcus salivarius and Streptococcus mitis responsible for initiation of dental carries. Tooth decay is infectious disease an worldwide, which may occur in patients of every age. Nanotechnology creates a new approach of designing of medical devices preventing or reducing bacterial colonization. Colloidal silver solution (CSS) of concentration 350 ppm was used in this research. Nanoparticles size, shape and solution stability were evaluated. 16 strains of cariogenic bacteria, 4 isolates of each species: S. mutans, S. salivarius, S. sanguinis and S, mitis were obtained from plaque swabs of 7 patients treated for dental carries at Department of Conservative Dentistry, Medical University of Warsaw. MIC and MBC values for CSS's were evaluated. CSS used in this research is of good stability. No agglomeration or coalescence was observed during 24 hours of experiment. Silver nanoparticles were of round shape and had mean size of 67 nm. MIC values were: 12-25 ppm for S. salivarius, 25 ppm for S. sanguinis, 50-100 ppm for S. mitis and 50 ppm for S. mutans, while MBC values after 1 hour of bacterial contact with nanoparticles were 200-350 ppm for all cariogenic bacterial species. After 24 hours of contact MBC values were: 25-50 ppm for S. salivarius and S. sanguinis, 100-200 ppm for S. mitis and 200 ppmfor S. mutans. Antimicrobial properties of CSS depend on nanoparticles concentration and interaction time with

  2. Antimicrobial properties of coconut husk aqueous extract on cariogenic bacteria

    Directory of Open Access Journals (Sweden)

    Maria B Cyriac

    2013-01-01

    Full Text Available Background and Objectives: The husk fibers of coconut (Cocos nucifera are reported to be used by people of rural areas of South India for daily cleaning their teeth. As the beneficial effects of this plant material, with respect to antimicrobial properties against common cariogenic bacteria, are not scientifically proven, the present study was conducted. Materials and Methods: The husk of coconut was collected and aqueous extract was prepared and antimicrobial properties against common oral pathogens like Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis, and Lactobacillus acidophilus were performed by agar well diffusion method. The values obtained were then subjected to statistical analysis using one way ANOVA and Tukey HSD. Results: Aqueous extract of coconut husk showed a concentration-dependent antimicrobial activity against different tested organisms with zone of inhibition ranging from 4.44 to 15.33 mms. However, the efficacy was less in comparison to chlorhexidine. Conclusion: Inhibitory action against cariogenic bacteria exhibited by aqueous extract of coconut husk indicate presence of highly effective active compounds in these extracts, which can be identified and incorporated into modern oral care systems for controlling dental caries.

  3. Purification and some properties of G-factor from the silk gland of silkworm

    International Nuclear Information System (INIS)

    Taira, Hideharu; Ejiri, Shin-ichiro; Shimura, Kensuke

    1972-01-01

    Purification of G-factor from the silk gland of silkworms and some of its properties have been studied in comparison with the G-factor from E. coli and rat liver transferase II. In the experiment, GTP-γ- 32 P was prepared from GDP and 32 Pi by photophosphorylation with spinach chloroplasts, and purified by Dowex-1 chromatography. The purified G-factor was homogeneous on disc gel electrophoresis. Molecular weight of 80,000 was estimated from a calibrated Sephadex G-200 column. The purified G-factor exhibited uncoupled ribosome-dependent GTPase activity, and was inhibited by fusidic acid, SH inhibitor, and diphtheria toxin plus NAD. The G-factor from E. coli and that from the silk gland were not interchangeable in GTPase reaction. (Yamanoto, Y.)

  4. Unicellular cyanobacteria synechocystis accommodate heterotrophic bacteria with varied enzymatic and metal resistance properties

    Digital Repository Service at National Institute of Oceanography (India)

    Anas, A.; Sageer, S.; Jasmin, C.; Vijayan, V.; Pavanan, P.; Athiyanathil, S.; Nair, S.

    The interactions between heterotrophic bacteria and primary producers have a profound impact on the functioning of marine ecosystem. We characterized the enzymatic and metal resistance properties of fourteen heterotrophic bacteria isolated from a...

  5. Adhesion Properties of Lactic Acid Bacteria on Intestinal Mucin

    Directory of Open Access Journals (Sweden)

    Keita Nishiyama

    2016-09-01

    Full Text Available Lactic acid bacteria (LAB are Gram-positive bacteria that are natural inhabitants of the gastrointestinal (GI tracts of mammals, including humans. Since Mechnikov first proposed that yogurt could prevent intestinal putrefaction and aging, the beneficial effects of LAB have been widely demonstrated. The region between the duodenum and the terminal of the ileum is the primary region colonized by LAB, particularly the Lactobacillus species, and this region is covered by a mucus layer composed mainly of mucin-type glycoproteins. The mucus layer plays a role in protecting the intestinal epithelial cells against damage, but is also considered to be critical for the adhesion of Lactobacillus in the GI tract. Consequently, the adhesion exhibited by lactobacilli on mucin has attracted attention as one of the critical factors contributing to the persistent beneficial effects of Lactobacillus in a constantly changing intestinal environment. Thus, understanding the interactions between Lactobacillus and mucin is crucial for elucidating the survival strategies of LAB in the GI tract. This review highlights the properties of the interactions between Lactobacillus and mucin, while concomitantly considering the structure of the GI tract from a histochemical perspective.

  6. Abundance and diversity of ammonia-oxidizing archaea and bacteria on granular activated carbon and their fates during drinking water purification process.

    Science.gov (United States)

    Niu, Jia; Kasuga, Ikuro; Kurisu, Futoshi; Furumai, Hiroaki; Shigeeda, Takaaki; Takahashi, Kazuhiko

    2016-01-01

    Ammonia is a precursor to trichloramine, which causes an undesirable chlorinous odor. Granular activated carbon (GAC) filtration is used to biologically oxidize ammonia during drinking water purification; however, little information is available regarding the abundance and diversity of ammonia-oxidizing archaea (AOA) and bacteria (AOB) associated with GAC. In addition, their sources and fates in water purification process remain unknown. In this study, six GAC samples were collected from five full-scale drinking water purification plants in Tokyo during summer and winter, and the abundance and community structure of AOA and AOB associated with GAC were studied in these two seasons. In summer, archaeal and bacterial amoA genes on GACs were present at 3.7 × 10(5)-3.9 × 10(8) gene copies/g-dry and 4.5 × 10(6)-4.2 × 10(8) gene copies/g-dry, respectively. In winter, archaeal amoA genes remained at the same level, while bacterial amoA genes decreased significantly for all GACs. No differences were observed in the community diversity of AOA and AOB from summer to winter. Phylogenetic analysis revealed high AOA diversity in group I.1a and group I.1b in raw water. Terminal-restriction fragment length polymorphism analysis of processed water samples revealed that AOA diversity decreased dramatically to only two OTUs in group I.1a after ozonation, which were identical to those detected on GAC. It suggests that ozonation plays an important role in determining AOA diversity on GAC. Further study on the cell-specific activity of AOA and AOB is necessary to understand their contributions to in situ nitrification performance.

  7. Surfactant-free purification of membrane protein complexes from bacteria: application to the staphylococcal penicillin-binding protein complex PBP2/PBP2a

    International Nuclear Information System (INIS)

    Paulin, Sarah; Rosado, Helena; Taylor, Peter W; Jamshad, Mohammed; Dafforn, Timothy R; Garcia-Lara, Jorge; Foster, Simon J; Galley, Nicola F; Roper, David I

    2014-01-01

    Surfactant-mediated removal of proteins from biomembranes invariably results in partial or complete loss of function and disassembly of multi-protein complexes. We determined the capacity of styrene-co-maleic acid (SMA) co-polymer to remove components of the cell division machinery from the membrane of drug-resistant staphylococcal cells. SMA-lipid nanoparticles solubilized FtsZ-PBP2-PBP2a complexes from intact cells, demonstrating the close physical proximity of these proteins within the lipid bilayer. Exposure of bacteria to (-)-epicatechin gallate, a polyphenolic agent that abolishes β-lactam resistance in staphylococci, disrupted the association between PBP2 and PBP2a. Thus, SMA purification provides a means to remove native integral membrane protein assemblages with minimal physical disruption and shows promise as a tool for the interrogation of molecular aspects of bacterial membrane protein structure and function. (paper)

  8. Chitinases from Bacteria to Human: Properties, Applications, and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Abhishek Singh Rathore

    2015-01-01

    Full Text Available Chitin is the second most plenteous polysaccharide in nature after cellulose, present in cell walls of several fungi, exoskeletons of insects, and crustacean shells. Chitin does not accumulate in the environment due to presence of bacterial chitinases, despite its abundance. These enzymes are able to degrade chitin present in the cell walls of fungi as well as the exoskeletons of insect. They have shown being the potential agents for biological control of the plant diseases caused by various pathogenic fungi and insect pests and thus can be used as an alternative to chemical pesticides. There has been steady increase in demand of chitin derivatives, obtained by action of chitinases on chitin polymer for various industrial, clinical, and pharmaceutical purposes. Hence, this review focuses on properties and applications of chitinases starting from bacteria, followed by fungi, insects, plants, and vertebrates. Designing of chitinase by applying directed laboratory evolution and rational approaches for improved catalytic activity for cost-effective field applications has also been explored.

  9. Purification and properties of Cu-Zn superoxide dismutase extracted from Brucella abortus strain 19

    Energy Technology Data Exchange (ETDEWEB)

    Tabatabai, L.B. (ARS-USDA, Ames, IA (United States))

    1991-03-11

    Recent work showed that a recombinant 20 kDa protein from Brucella abortus expressed in E. coli is a Cu-Zn superoxide dismutase (SOD). Western blot and ELISA results indicated that cattle with brucellosis have antibody to SOD. Here the authors report the purification and properties of the native B. abortus Cu-Zn SOD. SOD was extracted from methanol-killed Brucella abortus strain 19 with 0.1 M sodium citrate-1.0 M sodium chloride solution. The extract was dialyzed and protein precipitated by ammonium sulfate at 70-100% saturation was collected. The SOD was purified by HPLC anion exchange chromatography. SOD activity was assayed with a coupled enzyme assay using xanthine oxidase-cytochrome C reduction assay. The authors determined that the Brucella SOD is present in two molecular forms both inhibitable with KCN with Ki's of 0.32 mM and 4.98 mM, respectively. No other form of SOD was identified in the extract. Polyclonal antibody to SOD and polyclonal antibody to SOD synthetic peptide residues 134-143 inhibited SOD activity by 50% and 13%, respectively. Both SOD and the synthetic peptide inhibited binding of anti-SOD antibody to SOD by 60% and 20%, respectively. Based on these results the SOD and its amphipathic peptide will be considered as candidates for the design of synthetic multiple peptide vaccines and diagnostic reagents for bovine brucellosis.

  10. Fluxing purification and its effect on magnetic properties of high-B{sub s} FeBPSiC amorphous alloy

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Jing [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang, Liaoning 110870 (China); Wang, Anding, E-mail: anding@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Yue, Shiqiang [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Kong, Fengyu [School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315016 (China); Qiu, Keqiang, E-mail: kqqiu@163.com [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang, Liaoning 110870 (China); Chang, Chuntao; Wang, Xinmin [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Liu, Chain-Tsuan, E-mail: chainliu@cityu.edu.hk [Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong (China)

    2017-07-01

    Highlights: • Surface crystallization in Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} ribbon was inhibited by flux purification. • Amorphous Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} ribbon was made with industrial process and materials. • The ribbons exhibit high B{sub s} of 1.65 T, low H{sub c} of 2 A/m, and high μ{sub e} of 9.7 × 10{sup 3}. • High melting point inclusions trigger the surface crystallization as nuclei. - Abstract: A high-B{sub s} amorphous alloy with the base composition Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} was used to study the effects of fluxing purification on amorphous forming ability and magnetic properties of the alloy prepared with raw materials in industrialization. By using fluxing purification, the surface crystallization was suppressed and fully amorphous Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} ribbons with a maximum thickness of 48 μm were successfully achieved by using an industrial process and materials. The amorphous ribbons made with industrial-purified alloys exhibit excellent magnetic properties, containing high-B{sub s} of 1.65 T, low H{sub c} of 2.0 A/m, and high μ{sub e} of 9.7 × 10{sup 3} at 1 kHz. Impurities in the melting alloys exist in three forms and have different effluences on magnetic properties. The surface crystallization was triggered by the impurities which exist as high melting point inclusions serving as nuclei. Thus, fluxing purification is a feasible way for industrialization of high-B{sub s} FeBPSiC amorphous alloys.

  11. Technologically important properties of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    SERVER

    2007-07-18

    Jul 18, 2007 ... facultatively heterofermentative lactobacilli. Lactic acid bacteria were identified on the basis of phenotypic characters as Lactococcus lactis subsp. lactis, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum and.

  12. Purification of cress seed (Lepidium sativum) gum: Physicochemical characterization and functional properties

    DEFF Research Database (Denmark)

    Razmkhah, Somayeh; Mohammadifar, Mohammad Amin; Razavi, Seyed Mohammad Ali

    2016-01-01

    The aim of the present study was to investigate the effects of different purification methods (ethanol, isopropanol and ethanol-isopropanol) on the physicochemical and functional characteristics of cress seed gum. Sugar composition and molecular weight of the samples varied significantly. All...... the purification methods reduced ash and protein content and molecular weight of cress seed gum. The main decomposition of the purified samples started above 200º C and initial decomposition temperature of the crude gum was 190.21º C. DSC thermograms of the purified gums showed two exothermic events at 257.......81-261.95 ºC and 302.46-311.57 ºC. Crude gum displayed an exothermic peak at 259.42º C. Sample I (purified using isopropanol) imparted the best surface activity among the purified samples as it had the highest protein and uronic acid contents and the lowest Mw. All the purification methods could improve...

  13. RELATIONSHIP BETWEEN CELL SURFACE PROPERTIES AND TRANSPORT OF BACTERIA THROUGH SOIL

    Science.gov (United States)

    A study was conducted to relate the properties of Enterobacter, Pseudomonas, Bacillus, Achromobacter, Flavobacterium, and Arthrobacter strains to their transport with water moving through soil. the bacteria differed markedly in their extent of transport; their hydrophobicity, as...

  14. [Colonization properties of opportunistic bacteria isolated from children with pneumonia].

    Science.gov (United States)

    Kholodok, G N; Alekseeva, I N; Strel'nikova, N V; Kozlov, V K

    2014-01-01

    Evaluation of phenotypes and pathogenicity factors of 476 opportunistic bacteria isolated from respiratory samples of 973 children with community-acquired pneumonia and 36 children without respiratory infection symptoms. Quantitative method of tracheal aspirate and nasopharyngeal swab seeding into certified nutrient media was used, identification was carried out according to standard techniques. Adhesive, "anti-interferon", anti-lysozyme and inherent bactericidal activity of Escherichia coli and Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter spp. were established to ensure in combination with known aggression factors their colonization advantage compared with other pneumopathogens. Adhesion indexes of Gram-negative bacteria lower than 2.5 are shown as markers of invasive strains. Anti-lysozyme activity level lower than 2.14 microg/ml and lack of "anti-interferon" activity characterize non-invasive opportunistic bacteria strains. The detected phenotypic features of opportunistic bacteria may be used in clinical practice for evaluatio of etiologic importance of microorganisms isolated from tracheal aspirate in pneumonia patients.

  15. Antimicrobial properties of probiotic bacteria from various sources ...

    African Journals Online (AJOL)

    The probiotic potentials of lactic acid bacteria species isolated from various food sources (nono, ugba, ogiri, kunun-zaki and ogi) were studied. The predominant species among the isolated strains were Lactobacillus bulgaricus, Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus brevis, Streptococcus ...

  16. Purification and properties of a ribosomal casein kinase from rabbit reticulocytes

    DEFF Research Database (Denmark)

    Issinger, O G

    1977-01-01

    A casein kinase was isolated and purifed from rabbit reticulocytes. About 90% of the enzyme activity co-sedimented with the ribosomal fraction, whereas about 10% of the enzyme activity was found in the ribosome-free supernatant. Both casein kinases (the ribosome-bound enzyme as well as the free...

  17. Effect of purification method of β-chitin from squid pen on the properties of β-chitin nanofibers

    OpenAIRE

    Suenaga, Shin; Nikaido, Nozomi; Totani, Kazuhide; Kawasaki, Kazunori; Ito, Yoshihito; Yamashita, Kazuhiko; Osada, Mitsumasa

    2016-01-01

    The relationship between purification methods of β-chitin from squid pen and the physicochemical properties of β-chitin nanofibers (NFs) were investigated. Two types of β-chitin were prepared, with β-chitin (a → b) subjected to acid treatment for decalcification and then base treatment for deproteinization, while β-chitin (b → a) was treated in the opposite order. These β-chitins were disintegrated into NFs using wet pulverization. The β-chitin (b → a) NF dispersion has higher transmittance a...

  18. Purification and characterization of a GH43 β-xylosidase from Enterobacter sp. identified and cloned from forest soil bacteria.

    Science.gov (United States)

    Campos, Eleonora; Negro Alvarez, María José; Sabarís di Lorenzo, Gonzalo; Gonzalez, Sergio; Rorig, Marcela; Talia, Paola; Grasso, Daniel H; Sáez, Felicia; Manzanares Secades, Paloma; Ballesteros Perdices, Mercedes; Cataldi, Angel A

    2014-01-01

    The use of lignocellulosic biomass for second generation biofuels requires optimization of enzymatic breakdown of plant cell walls. In this work, cellulolytic bacteria were isolated from a native and two cultivated forest soil samples. Amplification of glycosyl hydrolases was attempted by using a low stringency-degenerate primer PCR strategy, using total soil DNA and bulk DNA pooled from positive colonies as template. A set of primers was designed based on Acidothermus cellulolyticus genome, by search of conserved domains of glycosyl hydrolases (GH) families of interest. Using this approach, a fragment containing an open reading frame (ORF) with 98% identity to a putative GH43 beta-xylosidase coding gene from Enterobacter cloacae was amplified and cloned. The full protein was expressed in Escherichia coli as N-terminal or C-terminal His-tagged fusions and purified under native conditions. Only N-terminal fusion protein, His-Xyl43, presented beta-xylosidase activity. On pNPX, optimal activity was achieved at pH 6 and 40 °C and Km and Kcat values were 2.92 mM and 1.32 seg(-1), respectively. Activity was also demonstrated on xylobiose (X2), with Km 17.8 mM and Kcat 380 s(-1). These results demonstrated that Xyl43 is a functional beta-xylosidase and it is the first evidence of this activity for Enterobacter sp. Copyright © 2013 Elsevier GmbH. All rights reserved.

  19. Probiotic properties of endemic strains of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Flora N. Tkhruni

    2013-01-01

    Full Text Available Strains of lactic acid bacteria (LAB isolated from various samples of matsun, yogurt and salted cheese from natural farms of Armenia were studied. They have high antimicrobial and probiotic activities, growth rate and differ by their resistance to enzymes. Supernatants of LAB retain bactericidal activity at рН 3.0-8.0 and inhibit growth of various microflora. The application of different methods of identification and LAB genotyping (API 50 CH, 16S rRNA sequencing, GS-PCR, RAPD PCR showed that isolated LAB evidenced a 99.9% similarity with L. rhamnosus, L. plantarum and L. pentosus species and coccoid forms of Streptococcus and Enterococcus species. It can be concluded, that some strains of lactic acid bacteria, isolated from dairy products from natural farms of Armenia, can be properly used for biopreservation of some foodstuffs. On the basis of experimental data, the LAB can be used as basis for obtaining the new products of functional nutrition.

  20. Subsurface Endospore-Forming Bacteria Possess Bio-Sealant Properties.

    Science.gov (United States)

    Basha, Sreenivasulu; Lingamgunta, Lakshman Kumar; Kannali, Jayakumar; Gajula, Swarna Kumari; Bandikari, Ramesh; Dasari, Sreenivasulu; Dalavai, Veena; Chinthala, Paramageetham; Gundala, Prasada Babu; Kutagolla, Peera; Balaji, Vinodh Kumar

    2018-04-24

    Concrete is a strong and fairly inexpensive building substance, but has several disadvantages like cracking that allows corrosion, thus reducing its lifespan. To mitigate these complications, long-lasting microbial self-healing cement is an alternative that is eco-friendly and also actively repairs cracks. The present paper describes the detailed experimental investigation on compressive strength of cement mortars, mixed with six alkaliphilic bacteria, isolated from subsurface mica mines of high alkalinity. The experiments showed that the addition of alkaliphilic isolates at different cell concentrations (10 4 and 10 6 cells/ml) enhanced the compressive strength of cement mortar, because the rapid growth of bacteria at high alkalinity precipitates calcite crystals that lead to filling of pores and densifying the concrete mix. Thus, Bacillus subtilis (SVUNM4) showed the highest compressive strength (28.61%) of cement mortar at 10 4 cells/ml compared to those of other five alkaliphilic isolates (Brevibacillus sp., SVUNM15-22.1%; P. dendritiformis, SVUNM11-19.9%; B. methylotrophicus, SVUNM9-16%; B. licheniformis, SVUNM14-12.7% and S. maltophilia, SVUNM13-9.6%) and controlled cement mortar as well. This method resulted in the filling of cracks in concrete with calcite (CaCO 3 ), which was observed by scanning electron microscopy (SEM). Our results showed that the alkaliphilic bacterial isolates used in the study are effective in self-healing and repair of concrete cracks.

  1. Purification and characterization of a surfactin-like molecule produced by Bacillus sp. H2O-1 and its antagonistic effect against sulfate reducing bacteria

    Directory of Open Access Journals (Sweden)

    Korenblum Elisa

    2012-11-01

    Full Text Available Abstract Background Bacillus sp. H2O-1, isolated from the connate water of a Brazilian reservoir, produces an antimicrobial substance (denoted as AMS H2O-1 that is active against sulfate reducing bacteria, which are the major bacterial group responsible for biogenic souring and biocorrosion in petroleum reservoirs. Thus, the use of AMS H2O-1 for sulfate reducing bacteria control in the petroleum industry is a promising alternative to chemical biocides. However, prior to the large-scale production of AMS H2O-1 for industrial applications, its chemical structure must be elucidated. This study also analyzed the changes in the wetting properties of different surfaces conditioned with AMS H2O-1 and demonstrated the effect of AMS H2O-1 on sulfate reducing bacteria cells. Results A lipopeptide mixture from AMS H2O-1 was partially purified on a silica gel column and identified via mass spectrometry (ESI-MS. It comprises four major components that range in size from 1007 to 1049 Da. The lipid moiety contains linear and branched β-hydroxy fatty acids that range in length from C13 to C16. The peptide moiety contains seven amino acids identified as Glu-Leu-Leu-Val-Asp-Leu-Leu. Transmission electron microscopy revealed cell membrane alteration of sulfate reducing bacteria after AMS H2O-1 treatment at the minimum inhibitory concentration (5 μg/ml. Cytoplasmic electron dense inclusions were observed in treated cells but not in untreated cells. AMS H2O-1 enhanced the osmosis of sulfate reducing bacteria cells and caused the leakage of the intracellular contents. In addition, contact angle measurements indicated that different surfaces conditioned by AMS H2O-1 were less hydrophobic and more electron-donor than untreated surfaces. Conclusion AMS H2O-1 is a mixture of four surfactin-like homologues, and its biocidal activity and surfactant properties suggest that this compound may be a good candidate for sulfate reducing bacteria control. Thus, it is a potential

  2. Salt-dependent properties of proteins from extremely halophilic bacteria

    Science.gov (United States)

    Lanyi, J. K.

    1974-01-01

    Based on information concerning the interaction of salts and macromolecules the literature of the enzymes of halophilic bacteria and their constituents is examined. Although in halophilic systems the salt requirement of enzyme activity is variable the enzymes investigated show a time-dependent inactivation at lower salt concentrations especially in the absence of salt. The studies described show that in some halophilic systems the effect of salt may be restricted to a small region on the protein molecule. The concept of the hydrophobic bond to consider certain solvent-dependent phenomena is introduced. It is shown that some halophilic enzymes are unable to maintain their structure without the involvement of hydrophobic interactions that are usually not supported by water. A table lists indices of hydrophobicity and polarity for various halophilic and nonhalophilic proteins.

  3. BACTERIOLOGICAL PROPERTIES OF MARINE WATER IN ADRIATIC FISH FARMS: ENUMERATION OF HETEROTROPHIC BACTERIA

    Directory of Open Access Journals (Sweden)

    Emin Teskeredžić

    2012-12-01

    Full Text Available Aquaculture is currently one of the fastest growing food production sectors in the world. Increase in nutrients and organic wastes lead to general deterioration of water quality. The problem of water quality is associated with both physical and chemical factors, as well as microbiological water quality. Heterotrophic bacteria play an important role in the process of decomposition of organic matter in water environment and indicate eutrophication process. Here we present our experience and knowledge on bacterial properties of marine water in the Adriatic fish farms with European sea bass (Dicentrarchus labrax L., 1758, with an emphasis on enumeration of heterotrophic bacteria in marine water. We applied two temperatures of incubation, as well as two methods for enumeration of heterotrophic bacteria: substrate SimPlate® test and spread plate method on conventional artificial media (Marine agar and Tryptic Soy agar with added NaCl. The results of analysis of bacteriological properties of marine water in the Adriatic fish farms showed that enumeration of heterotrophic bacteria in marine water depends on the applied incubation temperature and media for enumeration. At the same time, the incubation temperature of 22C favours more intense growth of marine heterotrophic bacteria, whereas a SimPlate test gives higher values of heterotrophic bacteria. Volatile values of heterotrophic bacteria during this research indicate a possible deterioration of microbiological water quality in the Adriatic fish farms and a need for regular monitoring of marine water quality.

  4. Investigation on adhering properties of dental materials by means of radioactively labelled bacteria

    International Nuclear Information System (INIS)

    Pfister, W.; Kleinert, P.; Sandig, H.C.; Wutzler, P.; Ruschitschka, A.; Schaefer, U.

    1987-01-01

    Bacteria of the species Streptococcus mutans were radioactively labelled with 113 In-oxinate. Different dental materials were incubated with the labelled bacteria. Counts per minute of the dental materials could be determined as proportion of the quantity of adhering microorganisms. Silver-palladium-alloy had a lower adherence than silver-tin-alloy. Finest polished alloys had lower adhering properties than unpolished surfaces of materials. (author)

  5. Purification and some properties of pectinesterase from potato (Solanum tuberosum L.) alpha cultivar

    OpenAIRE

    Montañez Sáenz, Julio; Téllez, Alejandro; Garza, Heliodoro de la; Reyes, María de la Luz; Contreras-Esquivel, Juan Carlos; Aguilar, Cristóbal Noé

    2000-01-01

    Pectinesterase was extracted from potato alpha cultivar, purified and partially characterized The used protocol resulted in a 58.8-fold purification (51 850.2 units/mg protein) with 15.5% recovery of pectinesterase activity. The purified enzyme had a molecular weight of 27 kDa and its isoelectric point was around 4.5 with pH and temperature optima of 8.0 and 60°C, respectively. The purified enzyme had a single symmetric peak of specific activity after chromatographic steps. The homogeneity of...

  6. Physicochemical characterization of fish protein adlayers with bacteria repelling properties

    DEFF Research Database (Denmark)

    Meyer, R. L.; Arpanaei, A.; Pillai, S.

    2013-01-01

    Materials coated with aqueous fish protein extracts can reduce bacterial adhesion, but the mechanism behind the observed effect is not fully understood. In this study we explore the physicochemical properties of fish muscle protein adlayers on four substrates: gold, stainless steel, polystyrene...

  7. Bacteria Buster: Testing Antibiotic Properties of Silver Nanoparticles

    Science.gov (United States)

    Gardner, Grant E.; Jones, M. Gail

    2009-01-01

    Nanoscale science and engineering are disciplines that examine the unique behaviors and properties of materials that emerge at the size range of 1 to 100 nanometers (a billionth of a meter). Nanobiotechnology is a sub-discipline of nanoscience that has arisen more recently. Nanobiotechnology is already impacting the fields of healthcare and…

  8. Purification and properties of a ribosomal casein kinase from rabbit reticulocytes

    DEFF Research Database (Denmark)

    Issinger, O G

    1977-01-01

    A casein kinase was isolated and purifed from rabbit reticulocytes. About 90% of the enzyme activity co-sedimented with the ribosomal fraction, whereas about 10% of the enzyme activity was found in the ribosome-free supernatant. Both casein kinases (the ribosome-bound enzyme as well as the free...... enzyme) showed identical activity and the same molecular weight. On sodium dodecyl sulphate/polyacrylamide-gel electrophoresis a single band of about 70 000 mol.wt. was observed. Sucrose-gradient analysis, however, showed that the enzyme activity sedimented with a s20,w of approx. 7.5S. This observation...... suggested that the casein kinase is a dimer composed of subunits of identical molecular weight. The enzyme utilizes GTP as well as ATP as a phosphoryl donor. It preferentially phosphorylates acidic proteins, in particular the model substrates casein and phosvitin. Casein kinase is cyclic AMP...

  9. Antigenotoxic properties of lactic acid bacteria in the S. typhimurium mutagenicity assay.

    Science.gov (United States)

    Pool-Zobel, B L; Münzner, R; Holzapfel, W H

    1993-01-01

    A high percentage of human tumors is reported to be related to dietary habits. One way to improve the nutritional impact is to increase the intake of protective factors, such as inhibitors of DNA damage and other types of anticarcinogens. Specific strains of lactic acid bacteria used to ferment milk are promising candidates that may be antimutagenic and anticarcinogenic. We have studied the antimutagenicity of 10 isolated strains of beneficial lactic acid bacteria. Four types of fermented milk products were also studied for their protective properties. The effect of these bacteria on the yield of revertants induced by nitrosated beef extract was investigated in the Salmonella typhimurium mutagenicity assay. Eight of 10 isolated Lactobacillus strains reduced the yield of his+ revertants almost back to the levels of the untreated controls. Different fermented fresh yogurts containing viable bacteria (probably Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus or Lactobacillus acidophilus and Bifidobacteria) showed protective effects as well. The degree of suppressing revertants was independent of the yogurt's fat content. In contrast, yogurt products that had been heat treated were not inhibitory. The other fresh fermented milk products (e.g., buttermilk, kefir, and "Dickmilch") were not antimutagenic in this study. The results imply that some bacteria used in milk processing have an antimutagenic potential and that this property is specific for the bacterial strain.

  10. TECHNOLOGICAL AND FUNCTIONAL PROPERTIES OF LACTIC ACID BACTERIA: THE IMPORTANCE OF THESE MICROORGANISMS FOR FOOD

    Directory of Open Access Journals (Sweden)

    Amanda de Souza Motta

    2015-12-01

    Full Text Available Eacters of coccus or rods Gram-positive, catalase negative, non-sporulating, which produce lactic acid as the major end product during the fermentation of carbohydrates. When applied on food, provides beneficial effects to consumers through its functional and technological properties. With this the present review article, explore the potential application of lactic acid bacteria in food. The following genera are considered the principal lactic acid bacteria: Aerococcus, Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella. These cultures have been used as starter or adjunct cultures for the fermentation of foods and beverages due to their contributions to the sensorial characteristics of these products and by microbiological stability. Their probiotic properties have also been investigated. More recent studies by indigenous cultures have received increased attention in light of the search for isolated cultures of a given raw material and a certain region. These microorganisms are being investigated for its functional and technological potential that may be applied in product development with its own characteristics and designation of origin. Those properties will be discussed in the present review in order to highlight the performance of these bacteria and the high degree of control over the fermentation process and standardization of the final product. The use of autochthonous cultures will be considered due the increase of studies of new cultures of lactic acid bacteria isolated of milk and meat of distinct products.

  11. Purification and Biochemical Properties of Phytochromobilin Synthase from Etiolated Oat Seedlings1

    Science.gov (United States)

    McDowell, Michael T.; Lagarias, J. Clark

    2001-01-01

    Plant phytochromes are dependent on the covalent attachment of the linear tetrapyrrole chromophore phytochromobilin (PΦB) for photoactivity. In planta, biliverdin IXα (BV) is reduced by the plastid-localized, ferredoxin (Fd)-dependent enzyme PΦB synthase to yield 3Z-PΦB. Here, we describe the >50,000-fold purification of PΦB synthase from etioplasts from dark-grown oat (Avena sativa L. cv Garry) seedlings using traditional column chromatography and preparative electrophoresis. Thus, PΦB synthase is a very low abundance enzyme with a robust turnover rate. We estimate the turnover rate to be >100 s−1, which is similar to that of mammalian NAD(P)H-dependent BV reductase. Oat PΦB synthase is a monomer with a subunit mass of 29 kD. However, two distinct charged forms of the enzymes were identified by native isoelectric focusing. The ability of PΦB synthase to reduce BV is dependent on reduced 2Fe-2S Fds. A Km for spinach (Spinacea oleracea) Fd was determined to be 3 to 4 μm. PΦB synthase has a high affinity for its bilin substrate, with a sub-micromolar Km for BV. PMID:11500553

  12. Purification and biochemical properties of phytochromobilin synthase from etiolated oat seedlings.

    Science.gov (United States)

    McDowell, M T; Lagarias, J C

    2001-08-01

    Plant phytochromes are dependent on the covalent attachment of the linear tetrapyrrole chromophore phytochromobilin (P Phi B) for photoactivity. In planta, biliverdin IX alpha (BV) is reduced by the plastid-localized, ferredoxin (Fd)-dependent enzyme P Phi B synthase to yield 3Z-P Phi B. Here, we describe the >50,000-fold purification of P Phi B synthase from etioplasts from dark-grown oat (Avena sativa L. cv Garry) seedlings using traditional column chromatography and preparative electrophoresis. Thus, P Phi B synthase is a very low abundance enzyme with a robust turnover rate. We estimate the turnover rate to be >100 s(-1), which is similar to that of mammalian NAD(P)H-dependent BV reductase. Oat P Phi B synthase is a monomer with a subunit mass of 29 kD. However, two distinct charged forms of the enzymes were identified by native isoelectric focusing. The ability of P Phi B synthase to reduce BV is dependent on reduced 2Fe-2S Fds. A K(m) for spinach (Spinacea oleracea) Fd was determined to be 3 to 4 microM. P Phi B synthase has a high affinity for its bilin substrate, with a sub-micromolar K(m) for BV.

  13. Mammalian folylpoly-γ-glutamate synthetase. 1. Purification and general properties of the hog liver enzyme

    International Nuclear Information System (INIS)

    Cichowicz, D.J.; Shane, B.

    1987-01-01

    Folylpolyglutamate synthetase was purified 30,000-150,000-fold from hog liver. Purification required the use of protease inhibitors, and the protein was purified to homogeneity in two forms. Both forms of the enzyme were monomers of M/sub r/ 62,000 and had similar specific activities. The specific activity of the homogeneous protein was over 2000-fold higher than reported for partially purified folylpolyglutamate synthetases from other mammalian sources. Enzyme activity was absolutely dependent on the presence of a reducing agent and a monovalent cation, of which K + was most effective. The purified enzyme catalyzed a MgATP-dependent addition of glutamate to tetrahydrofolate with the concomitant stoichiometric formation of MgADP and phosphate. Under conditions that resembled the expected substrate and enzyme concentrations in hog liver, tetrahydrofolate was metabolized to long glutamate chain length derivatives with the hexaglutamate, the major in vivo folate derivative, predominating. Enzyme activity was maximal at about pH 9.5. The high-pH optimum was primarily due to an increase in the K/sub m/ value for the L-glutamate substrate at lower pH values, and the reaction proceeded effectively at physiological pH provided high levels of glutamate were supplied

  14. Extracellular lipase of Aspergillus niger NRRL3; production, partial purification and properties.

    Science.gov (United States)

    Adham, Nehad Z; Ahmed, E M

    2009-03-01

    Four strains of Aspergillus niger were screened for lipase production. Each was cultivated on four different media differing in their contents of mineral components and sources of carbon and nitrogen. Aspergillus niger NRRL3 produced maximal activity (325U/ml) when grown in 3% peptone, 0.05% MgSO(4).7H(2)O, 0.05% KCl, 0.2% K(2)HPO(4) and 1% olive oil:glucose (0.5:0.5). A. niger NRRL3 lipase was partially purified by ammonium sulphate precipitation. The majority of lipase activity (48%) was located in fraction IV precipitated at 50-60% of saturation with a 18-fold enzyme purification. The optimal pH of the partial purified lipase preparation for the hydrolysis of emulsified olive oil was 7.2 and the optimum temperature was 60°C. At 70°C, the enzyme retained more than 90% of its activity. Enzyme activity was inhibited by Hg(2+) and K(+), whereas Ca(2+) and Mn(2+) greatly stimulated its activity. Additionally, the formed lipase was stored for one month without any loss in the activity.

  15. A new mannose-specific lectin from daylily (Hemerocallis fulva L. rhizome: purification and properties

    Directory of Open Access Journals (Sweden)

    V. O. Antonyuk

    2013-04-01

    Full Text Available A new lectin was purified from the daylily (Hemerocallis fulva L. with the yield of approximately 10 mg per kg of fresh plant rhizome. The purification procedure was based on application of the affinity chromathography on the column with yeast mannan and the ion-exchange chromatography on the column with DEAE-Toyopearl. The lectin possessed low affinity for α-methyl-D-mannopyranoside, D-fructose, D-turanose and 2-acetamido-D-galactopyranose and hight affinity for the yeast mannan. The lectin bound with greatly less affinity for the mannose-containig glycoproteins, such as ovoalbumin, ovomucoid and horseradish peroxidase. According to the results of electrophoresis in 20% DSNa-PAGE, the lectin consists of subunits of 12 kDa molecular weight. According to the results of gel-chromatography on the Toyopearl HW-55, the lectin’s molecular weight is 48 kDa. It agglutinated rabbit erythrocytes very well, while rat and guinea-pig erythrocytes were agglutinated worse, and human erythrocytes were not agglutinated at all. Lectin’s dialysis against 1% EDTA or heating to 60 ºC for 60 min did not stop its hemagglutinating activity.

  16. Hygrothermal Effect on Mechanical and Fatigue Properties of laminated Lower Limb Socket and Bacteria Growth

    Directory of Open Access Journals (Sweden)

    Fadhel Abbas Abdullah

    2016-12-01

    Full Text Available In this work, hygrothermal effect on the mechanical and fatigue properties of prosthetic socket lamination and its effect on the bacteria growth were studied. Two laminations composite materials were used in manufacturing prosthetic socket by using vacuum device. The reinforced materials of these laminations were perlon and carbon nanopowder (CNP while the matrix material was polyurethane resin. Tests performed in this work were the moisture absorption properties test to calculate percent moisture content according to ASTM 5229, tensile and fatigue tests with and without the hygrothermal effect to find the mechanical and fatigue properties, and the bacteria growth test under the hygrothermal effect to calculate the number of bacteria on the laminations. The results showed that the lamination (10 perlon+1 wt % CNP has mechanical properties than lamination (10 perlon with and without hygrothermal effect. The mechanical and fatigue properties for the two laminations were decreasing with increasing temperature and moisture.. Adding carbon nanopowder to the lamination (10 perlon increased ultimate stress, modulus of elastic, and endurance limit by (1.36, 2.35, and2.72 time respectively. Finally, the results showed that the Staphylococcus aureus growth increases with increasing temperature and moisture on the two laminations used in manufacturing prosthetic socket, and adding carbon nanopowder also increased the Staphylococcus aureus growth on the lamination.

  17. THE SEARCH AND PROPERTIES OF LACTIC ACID BACTERIA PERSPECTIVE FOR BIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Naumenko О. V.

    2014-10-01

    Full Text Available Search of biologically active Lactobacillus strains prospective for functional milk food production was the aim of the research. The study involved the lactic acid bacteria isolated from biological material of healthy humen and non- dairy lactic products. Using modern methodological approaches, the strains of lactic acid bacteria such as Lactobacillus casei 302, Lactobacillus acidophilus 35 and Streptococcus thermophilus 21 having high level of biological activity were selected. High biological potential of selected cultures of lactic acid bacteria, which could provide stability for the technological process of production and essential characteristics of bacterial preparations and fermented their products, was set. In vitro the experiments demonstrated that selected strains had valuable production properties, namely the ability to reduce level of cholesterol and lactose during development in milk, were resistant to virulent bacteriophages and aggressive compounds of the gastrointestinal tract, and high adhesive and antagonistic activities as well.

  18. Purification and some properties of pectinesterase from potato (Solanum tuberosum L. alpha cultivar

    Directory of Open Access Journals (Sweden)

    Julio Montañez Sáenz

    2000-01-01

    Full Text Available Pectinesterase was extracted from potato alpha cultivar, purified and partially characterized The used protocol resulted in a 58.8-fold purification (51 850.2 units/mg protein with 15.5% recovery of pectinesterase activity. The purified enzyme had a molecular weight of 27 kDa and its isoelectric point was around 4.5 with pH and temperature optima of 8.0 and 60°C, respectively. The purified enzyme had a single symmetric peak of specific activity after chromatographic steps. The homogeneity of the purified pectinesterase was confirmed by gel filtration and polyacrylamide electrophoresis gel.A pectinesterase foi extraída da batata (cultivar do alfa, purificada e parcialmente caracterizada. O protocolo usado levou a uma proteína purificada 58,8 vezes (51 850,2 units/mg da proteína com uma recuperação de 15,5 % da atividade da proteína. A enzima purificada apresentou um peso molecular de 27 kDa e seu ponto isoelétrico foi ao redor 4,5. A pectinesterase exibiu pH e temperatura ótimos de respectivamente 8,0 e 60°C. A enzima purificada apresentou um único pico simétrico de atividade específica após as etapas de cromatografia. A homogeneidade da pectinesterase purificada foi confirmada por filtração em gel e por eletroforese em gel de poliacrilamida.

  19. The Production, Purification and Properties of the Biopolymer Levan Produced by the Bacterium Erwinia Herbicola

    Science.gov (United States)

    1989-08-01

    after comparison with ATCC 11142 Acetobacter pasteurianus. ATCC 15953 Microbacterium 2 laevanlformans. and QMB 1624 Bacillus coagulans (B, gub^jlu...is produced by several bacteria, including Brwjnja herbicola. Streptococcus salivarius. Pseudomonas prunicola. Bacillus subtilis. and Actinomvcetes...J, i X I i rtfi ii i IT PTT-n T~^L^^^^ r1 •» ■ ■ 11 ■ ■ ■ i >■ 111 I’I I’.VIT fi-H-rtfi 1 -f ’ •■» i | i r , , , Levan from Bacillus

  20. The Extraction and Partial Purification of Bacterial DNA as a Practical Exercise for GCE Advanced Level Students.

    Science.gov (United States)

    Falconer, A. C.; Hayes, L. J.

    1986-01-01

    Describes a relatively simple method of extraction and purification of bacterial DNA. This technique permits advanced secondary-level science students to obtain adequate amounts of DNA from very small pellets of bacteria and to observe some of its polymer properties. (ML)

  1. Effect of purification method of β-chitin from squid pen on the properties of β-chitin nanofibers.

    Science.gov (United States)

    Suenaga, Shin; Nikaido, Nozomi; Totani, Kazuhide; Kawasaki, Kazunori; Ito, Yoshihito; Yamashita, Kazuhiko; Osada, Mitsumasa

    2016-10-01

    The relationship between purification methods of β-chitin from squid pen and the physicochemical properties of β-chitin nanofibers (NFs) were investigated. Two types of β-chitin were prepared, with β-chitin (a→b) subjected to acid treatment for decalcification and then base treatment for deproteinization, while β-chitin (b→a) was treated in the opposite order. These β-chitins were disintegrated into NFs using wet pulverization. The β-chitin (b→a) NF dispersion has higher transmittance and viscosity than the β-chitin (a→b) NF dispersion. For the first time, we succeeded in obtaining 3D images of the β-chitin NF dispersion in water by using quick-freeze deep-etch replication with high-angle annular dark field scanning transmission electron microscopy. The β-chitin (b→a) NF dispersion has a denser and more uniform 3D network structure than the β-chitin (a→b) NF dispersion. Widths of the β-chitin (a→b) and (b→a) NFs were approximately 8-25 and 3-10nm, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Soil chemical properties affect the reaction of forest soil bacteria to drought and rewetting stress.

    Science.gov (United States)

    Chodak, Marcin; Gołębiewski, Marcin; Morawska-Płoskonka, Justyna; Kuduk, Katarzyna; Niklińska, Maria

    Reaction of soil bacteria to drought and rewetting stress may depend on soil chemical properties. The objectives of this study were to test the reaction of different bacterial phyla to drought and rewetting stress and to assess the influence of different soil chemical properties on the reaction of soil bacteria to this kind of stress. The soil samples were taken at ten forest sites and measured for pH and the contents of organic C (C org ) and total N (N t ), Zn, Cu, and Pb. The samples were kept without water addition at 20 - 30 °C for 8 weeks and subsequently rewetted to achieve moisture equal to 50 - 60 % of their maximum water-holding capacity. Prior to the drought period and 24 h after the rewetting, the structure of soil bacterial communities was determined using pyrosequencing of 16S rRNA genes. The drought and rewetting stress altered bacterial community structure. Gram-positive bacterial phyla, Actinobacteria and Firmicutes , increased in relative proportion after the stress, whereas the Gram-negative bacteria in most cases decreased. The largest decrease in relative abundance was for Gammaproteobacteria and Bacteroidetes . For several phyla the reaction to drought and rewetting stress depended on the chemical properties of soils. Soil pH was the most important soil property influencing the reaction of a number of soil bacterial groups (including all classes of Proteobacteria , Bacteroidetes , Acidobacteria , and others) to drought and rewetting stress. For several bacterial phyla the reaction to the stress depended also on the contents of N t and C org in soil. The effect of heavy metal pollution was also noticeable, although weaker compared to other chemical soil properties. We conclude that soil chemical properties should be considered when assessing the effect of stressing factors on soil bacterial communities.

  3. Effect of pore formers on properties of tape cast porous sheets for electrochemical flue gas purification

    DEFF Research Database (Denmark)

    Schmidt, Cristine Grings; Kammer Hansen, Kent; Andersen, Kjeld Bøhm

    2016-01-01

    permeability measurements, mercury porosimetry and pore orientation measurements, to investigate the role of the different pore formers on the properties after sintering at a temperature of 1250°C. Those tapes prepared from different non-spherical pore formers with comparable porosity of about 43%, showed...

  4. Structure/property relationships in polymer membranes for water purification and energy applications

    Science.gov (United States)

    Geise, Geoffrey

    Providing sustainable supplies of purified water and energy is a critical global challenge for the future, and polymer membranes will play a key role in addressing these clear and pressing global needs for water and energy. Polymer membrane-based processes dominate the desalination market, and polymer membranes are crucial components in several rapidly developing power generation and storage applications that rely on membranes to control rates of water and/or ion transport. Much remains unknown about the influence of polymer structure on intrinsic water and ion transport properties, and these relationships must be developed to design next generation polymer membrane materials. For desalination applications, polymers with simultaneously high water permeability and low salt permeability are desirable in order to prepare selective membranes that can efficiently desalinate water, and a tradeoff relationship between water/salt selectivity and water permeability suggests that attempts to prepare such materials should rely on approaches that do more than simply vary polymer free volume. One strategy is to functionalize hydrocarbon polymers with fixed charge groups that can ionize upon exposure to water, and the presence of charged groups in the polymer influences transport properties. Additionally, in many emerging energy applications, charged polymers are exposed to ions that are very different from sodium and chloride. Specific ion effects have been observed in charged polymers, and these effects must be understood to prepare charged polymers that will enable emerging energy technologies. This presentation discusses research aimed at further understanding fundamental structure/property relationships that govern water and ion transport in charged polymer films considered for desalination and electric potential field-driven applications that can help address global needs for clean water and energy.

  5. Symbiotic Properties of Sinorhizobium Fredii, J-TGS50 an Indonesian Soybean Nodule Forming Bacteria

    International Nuclear Information System (INIS)

    Setiyo Hadi Waluyo

    2004-01-01

    Green House experiments were conducted to study symbiotic properties of Sinorhizobium Fredii, J-TGS50. Sinorhizobium Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217 and Bradyrhizobium japonicum USDA 110 were used as references. Yeast extract mannitol broth culture of the bacteria were made and used as inoculation for several local and imported soybean varieties used in this study. Plants were harvested at 20 days after inoculation. Number of nodules were counted, fresh weight of nodules and shoot were determined. S. Fredii J-TGS50 and S. Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217 were found different in their symbiotic properties. S. Fredii J-TGS50 formed nodules on same imported soybean. While there were no nodules obtained from the plant inoculated with S. Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217. S. Fredii J-TGS50 and recommended B. Japonicum USDA 110 formed nodule on several local soybean varieties. There was no differences between those two bacteria either in nodulation efficiency or in the effectiveness of the formed nodules. Results of this study can be concluded that S. Fredii, J-TGS50 is a native to Indonesian soil and it is a promising soybean nodule forming bacteria in Indonesia. Using indigenous bacteria is valuable. Since they are mostly more tolerant and adaptable than the introduced ones. An important aspect for the success of Biological Nitrogen Fixation (BNF) is insight in the structure of indigenous soybean rhizobia populations. Study on the biodiversity of soybean rhizobia was important conducted. (author)

  6. Purification and properties of NAD(P)H: (quinone-acceptor) oxidoreductase of sugarbeet cells.

    Science.gov (United States)

    Trost, P; Bonora, P; Scagliarini, S; Pupillo, P

    1995-12-01

    NAD(P)H:(quinone-acceptor) oxidoreductase [NAD(P)H-QR], a plant cytosolic protein, was purified from cultured sugarbeet cells by a combination of ammonium sulfate fractionation, FPLC Superdex 200 gel filtration, Q-Sepharose anion-exchange chromatography, and a final Blue Sepharose CL-6B affinity chromatography with an NADPH gradient. The subunit molecular mass is 24 kDa and the active protein (94 kDa) is a tetramer. The isoelectric point is 4.9. The enzyme was characterized by ping-pong kinetics and extremely elevated catalytic capacity. It prefers NADPH over NADH as electron donor (kcat/Km ratios of 1.7 x 10(8) M-1 S-1 and 8.3 x 10(7) M-1 S-1 for NADPH and NADH, respectively, with benzoquinone as electron acceptor). The acridone derivative 7-iodo-acridone-4-carboxylic acid is an efficient inhibitor (I0.5 = 5 x 10(-5) M), dicumarol is weakly inhibitory. The best acceptor substances are hydrophilic, short-chain quinones such as ubiquinone-0 (Q-0), benzoquinone and menadione, followed by duroquinone and ferricyanide, whereas hydrophobic quinones, cytochrome c and oxygen are reduced at negligible rates at best. Quinone acceptors are reduced by a two-electron reaction with no apparent release of free semiquinonic intermediates. This and the above properties suggest some relationship of NAD(P)H-QR to DT-diaphorase, an animal flavoprotein which, however, has distinct structural properties and is strongly inhibited by dicumarol. It is proposed that NAD(P)H-QR by scavenging unreduced quinones and making them prone to conjugation may act in plant tissues as a functional equivalent of DT-diaphorase.

  7. Purification and physicochemical properties of α-amylase from irradiated wheat

    International Nuclear Information System (INIS)

    Machaiah, J.P.; Vakil, U.K.

    1981-01-01

    α-Amylases from control and gamma-irradiated (at 0.2 and 2.0 kGy dose levels) wheat seedlings were purified to homogeneity and characterized. The molecular weight of the enzyme from a 2 kGy irradiated sample was slightly lower than that of the control; other general and catalytic properties also showed some differences. α-Amylase from the irradiated (2kGy) sample had a narrow range of pH optimum and was inactivated faster at alkaline pH and by heat treatment than the enzyme from unirradiated wheat. A high apparent Michaelis constant (Ksub(m)) and a low maximal velocity (Vsub(max)) for the hydrolysis of soluble starch catalyzed by the enzyme from irradiated (2kGy) wheat, suggested some modifications in the formation of the substrate α-amylase complex. Further, of the total number of amino acid residues lost on irradiation, dicarboxylic amino acids constituted the largest percentage; these structural alterations in the enzyme may be responsible for its partial inactivation. The total sugars liberated upon amylolysis of starch with the 2kGy irradiated enzyme were lower than control, and there was accumulation of higher maltodextrins in the place of maltose. (auth.)

  8. In Vitro Properties of Potential Probiotic Indigenous Lactic Acid Bacteria Originating from Traditional Pickles

    Directory of Open Access Journals (Sweden)

    Mehmet Tokatlı

    2015-01-01

    Full Text Available The suitable properties of potential probiotic lactic acid bacteria (LAB strains (preselected among 153 strains on the basis of their potential technological properties isolated from traditional Çubuk pickles were examined in vitro. For this purpose, these strains (21 Lactobacillus plantarum, 11 Pediococcus ethanolidurans, and 7 Lactobacillus brevis were tested for the ability to survive at pH 2.5, resistance to bile salts, viability in the presence of pepsin-pancreatin, ability to deconjugate bile salts, cholesterol assimilation, and surface hydrophobicity properties. Most of the properties tested could be assumed to be strain-dependent. However, L. plantarum and L. brevis species were found to possess desirable probiotic properties to a greater extent compared to P. ethanolidurans. In contrast to P. ethanolidurans strains, the tested L. plantarum and L. brevis strains exhibited bile salt tolerance, albeit to different extent. All tested strains showed less resistance to intestinal conditions than gastric juice environment. Based on the survival under gastrointestinal conditions, 22 of the 39 strains were selected for further characterization. The eight strains having the highest cholesterol assimilation and surface hydrophobicity ratios could be taken as promising probiotic candidates for further in vivo studies, because of the strongest variations found among the tested strains with regard to these properties.

  9. In Vitro Screening of Antibacterial Properties of Rhus coriaria and Origanum vulgare Against Some Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Hêro F.S. Akrayi

    2015-12-01

    Full Text Available This study investigates the antibacterial property of Rhus coriaria (Sumac and Origanum vulgare (Jatra aqueous extracts against Escherichia coli ATCC 25922, Klebsiella pneumoniae, Proteus mirabilis and Pseudomonas aeruginosa ATCC 27835. Results confirm the resistance of the bacterial isolates against more than three antibiotics. The aqueous extract of R. coriaria showed the highest activity as an inhibitor against tested bacteria, while the aqueous extract of O. vulgare shows low effect against the above mentioned bacteria. MIC for R. coriaria and O. vulgare aqueous extracts were determined for four bacterial isolates. The MIC of O. vulgare against tested bacteria was >12%, while the MIC of R. coriaria was 4% for E. coli, <0.025% for both K. pneumoniae and P. mirabilis and 2% for P. aeruginosa. The phytochemical groups of both plants extract were analyzed; the results indicated both plants contain tannins, phenols and saponins, flavonoid, alkaloid, and phlobatanin. The antimitotic effect of both plants extracts were investigated on Allium cepa, and the extracts showed inhibitory role in the root growth in contrast to the control when grown in the tap water for 5 days. In addition, the 24 hours treatment of grown roots in tap water with both extracts resulted in significant decrease in mitotic index.

  10. Purification and properties of a transglutaminase produced by a Bacillus circulans strain isolated from the Amazon environment.

    Science.gov (United States)

    de Barros Soares, Luís Henrique; Assmann, Francine; Záchia Ayub, Marco Antônio

    2003-06-01

    A new microbial transglutaminase (EC 2.3.2.13) from a Bacillus circulans strain isolated from the aquatic Amazonian environment was purified and characterized. Enzyme purification started with (NH(4))(2)SO(4) 'salting out' and proceeded with liquid chromatography on Q-Sepharose FF and octyl-Sepharose 4 FF. The purification factor was approx. 150-fold with a yield of 32%. The enzyme's molecular mass was estimated as 45000 Da on SDS/PAGE. The purified transglutaminase had an optimum temperature of 47 degrees C, the optimum pH of the reaction was 7 and it presented no calcium-dependent activity.

  11. Purification technologies for colloidal nanocrystals.

    Science.gov (United States)

    Shen, Yi; Gee, Megan Y; Greytak, A B

    2017-01-10

    Almost all applications of colloidal nanocrystals require some type of purification or surface modification process following nanocrystal growth. Nanocrystal purification - the separation of nanocrystals from undesired solution components - can perturb the surface chemistry and thereby the physical properties of colloidal nanocrystals due to changes in solvent, solute concentrations, and exposure of the nanocrystal surface to oxidation or hydrolysis. For example, nanocrystal quantum dots frequently exhibit decreased photoluminescence brightness after precipitation from the growth solvent and subsequent redissolution. Consequently, purification is an integral part of the synthetic chemistry of colloidal nanocrystals, and the effect of purification methods must be considered in order to accurately compare and predict the behavior of otherwise similar nanocrystal samples. In this Feature Article we examine established and emerging approaches to the purification of colloidal nanoparticles from a nanocrystal surface chemistry viewpoint. Purification is generally achieved by exploiting differences in properties between the impurities and the nanoparticles. Three distinct properties are typically manipulated: polarity (relative solubility), electrophoretic mobility, and size. We discuss precipitation, extraction, electrophoretic methods, and size-based methods including ultracentrifugation, ultrafiltration, diafiltration, and size-exclusion chromatography. The susceptibility of quantum dots to changes in surface chemistry, with changes in photoluminescence decay associated with surface chemical changes, extends even into the case of core/shell structures. Accordingly, the goal of a more complete description of quantum dot surface chemistry has been a driver of innovation in colloidal nanocrystal purification methods. We specifically examine the effect of purification on surface chemistry and photoluminescence in quantum dots as an example of the challenges associated with

  12. Hamiltonian purification

    Energy Technology Data Exchange (ETDEWEB)

    Orsucci, Davide [Scuola Normale Superiore, I-56126 Pisa (Italy); Burgarth, Daniel [Department of Mathematics, Aberystwyth University, Aberystwyth SY23 3BZ (United Kingdom); Facchi, Paolo; Pascazio, Saverio [Dipartimento di Fisica and MECENAS, Università di Bari, I-70126 Bari (Italy); INFN, Sezione di Bari, I-70126 Bari (Italy); Nakazato, Hiromichi; Yuasa, Kazuya [Department of Physics, Waseda University, Tokyo 169-8555 (Japan); Giovannetti, Vittorio [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56126 Pisa (Italy)

    2015-12-15

    The problem of Hamiltonian purification introduced by Burgarth et al. [Nat. Commun. 5, 5173 (2014)] is formalized and discussed. Specifically, given a set of non-commuting Hamiltonians (h{sub 1}, …, h{sub m}) operating on a d-dimensional quantum system ℋ{sub d}, the problem consists in identifying a set of commuting Hamiltonians (H{sub 1}, …, H{sub m}) operating on a larger d{sub E}-dimensional system ℋ{sub d{sub E}} which embeds ℋ{sub d} as a proper subspace, such that h{sub j} = PH{sub j}P with P being the projection which allows one to recover ℋ{sub d} from ℋ{sub d{sub E}}. The notions of spanning-set purification and generator purification of an algebra are also introduced and optimal solutions for u(d) are provided.

  13. A Straightforward Access to New Families of Lipophilic Polyphenols by Using Lipolytic Bacteria

    OpenAIRE

    S?nchez-Barrionuevo, Leyre; Gonz?lez-Benjumea, Alejandro; Escobar-Ni?o, Almudena; Garc?a, Mar?a Teresa; L?pez, ?scar; Maya, In?s; Fern?ndez-Bola?os, Jos? G.; C?novas, David; Mellado, Encarnaci?n

    2016-01-01

    The chemical synthesis of new lipophilic polyphenols with improved properties presents technical difficulties. Here we describe the selection, isolation and identification of lipolytic bacteria from food-processing industrial wastes, and their use for tailoring a new set of com- pounds with great interest in the food industry. These bacteria were employed to produce lipolytic supernatants, which were applied without further purification as biocatalysts in the chemoselective and regioselective...

  14. Properties of low-fat ultra-filtered cheeses produced with probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Miočinović Jelena

    2014-01-01

    Full Text Available Probiotics are live microorganisms that in certain numbers may confer a health benefit on the host. Nowadays, there are many dairy products on the market, especially fermented milks, with probiotics, and their popularity is rising. The aim of this article was to investigate the viability of commercial probiotic bacteria (Lactobacillus acidophilus LAFTI®L10 i Bifidobacterium lactis LAFTI®B94, DSM, Netherland as well as their influence on the changes of composition, pH, proteolysis, microbiological status and sensory properties of low-fat ultra-filtered (UF cheeses within 2 months of ripening. Low-fat cast ultra-filtered (UF cheeses were produced according to the defined production procedure by mixing UF milk protein powder, skim milk and cream, without (control cheese A and with adjunct probiotic culture (cheese B. The compositional parameters (milk fat, proteins and dry-matter content, pH, proteolysis parameters (water soluble nitrogen, nitrogen soluble in 5% PTA, urea and SDS PAG electrophoresis, as well as the numbers of starters and probiotic bacteria, were determined during ripening. In addition, sensory evaluations of cheeses were performed throughout the ripening time. A significant influence of probiotic strains on the composition, pH and primary proteolysis of cheese during ripening was not found. The counts of commercial probiotic bacteria were maintained at high levels (>107 cfug-1 during the overall ripening period, as a prerequisite of their therapeutic effects. The adjunct probiotic cultures enhanced the rate of secondary proteolysis, which was shown by the significantly higher levels of PTAN/TN of experimental compared to the control cheeses. The sensory evaluation showed that the overall aroma of low-fat cheeses was remarkably improved by the addition of the probiotic cultures used. Based on the results it can be concluded that the low-fat UF cheeses differ in good dietetic and functional properties as well as very acceptable

  15. Antimicrobial properties of lactic acid bacteria isolated from traditional yogurt and milk against Shigella strains.

    Science.gov (United States)

    Zare Mirzaei, Elnaze; Lashani, Elahe; Davoodabadi, Abolfazl

    2018-01-01

    Background: Lactic acid bacteria (LAB) are normal flora of the mouth, intestines and the female genital tract. They are also frequently found in meat, vegetables, and dairy products. Most of probiotic bacteria belong to the LAB group. Some probiotic LAB are useful in prevention and treatment of diarrheal diseases. The aim of this study was to investigate the antimicrobial properties of LAB isolated from traditional yogurt and milk against Shigella strains. Materials and methods: Forty LAB strains were isolated from traditional yogurt and milk. The antimicrobial activity of LAB against Shigella strains (eight S. flexneri , four S. sonnei ) was examined using the agar-well diffusion assay. LAB strains with antimicrobial effect against all Shigella strains were identified by 16S rRNA gene sequencing. Results: Six LAB strains inhibited the growth of all 12 Shigella strains. Lb. paracasei Y1-3, Lb. paracasei Y8-1 and Lb. fermentum Y2-2 were isolated from yogurt. Lb. paracasei M18-1, Lb. parelimentarius M4-3 and Lb. plantarum M19-1 were isolated from milk. Conclusion: This study showed that Lactobacillus strains with good inhibitory activity against S. flexneri and S. sonnei could be isolated from traditional yogurt and milk.

  16. Propolis Varnish: Antimicrobial Properties against Cariogenic Bacteria, Cytotoxicity, and Sustained-Release Profile

    Directory of Open Access Journals (Sweden)

    Mariana P. De Luca

    2014-01-01

    Full Text Available Varnishes are preparations that differ in the polymeric matrix and therapeutical agents. In dentistry they are used to prevent caries. In this study we developed a propolis varnish, considering propolis properties against cariogenic bacteria. To a chitosan polymeric base (CHV was added ethanolic propolis extract in different concentrations: PV1 (5%, PV2 (10%, and PV3 (15%. Antimicrobial activity was carried out against Streptococcus mutans (SM, Streptococcus sanguinis (SG, Streptococcus salivarius (SS, and Lactobacillus casei (LC through agar diffusion method. The three propolis concentrations incorporated were effective in inhibiting the growth of all microorganisms, but without significant difference between the zones of inhibition observed. Cytotoxicity assay was done by MTT method. Data were analyzed by one-way ANOVA and Bonferroni test. None of the varnishes were cytotoxic, keeping 80% of viable cells, while CHV allowed cellular proliferation (120%. Sustained-release test was carried out by applying 40 μL of each varnish in the buccal surface of bovine teeth and kept in an ethanol/water solution removed in regular times. According to the “independent model approach,” the release profiles were distinct from each varnish and the most prolonged was PV3 (8 weeks. Varnish formulations had satisfactory antimicrobial activity against cariogenic bacteria and have a low cytotoxicity (<50%.

  17. [REGULATING EFFECT OF ASSOCIATIVE MICROBIOTA ON THE RHYTHMS OF BIOLOGICAL PROPERTIES OF FUNGI AND BACTERIA].

    Science.gov (United States)

    Timokhina, T Kh; Bukharin, O V; Nikolenko, M V; Paromova, Ya I; Perunova, N B

    2015-01-01

    Study the effect of exometabolites of associative microbiota on circadian dynamics of functional parameters, that reflect pathogenic and persistence properties of fungi and bacteria. Clinical isolates of Candida albicans, isolated-from intestine of healthy individuals and patients with candidosis, as well as clinical isolates and museum ATCC strains Staphylococcus. aureus 25923, Escherichia coli 35218 and Pseudomonas aeruginosa 27853 were taken for study of proliferative, adhesive, catalase, protease, phospholipase, hemolytic, anti-lysozyme, biofilm-forming activity. The results were treated statistically. C. albicans isolates, isolated from healthy individuals were revealed to be indifferent to the effect of bacterial metabolites. Chrono-infrastructure of biological properties of fungi altered under the effect of microbiota metabolites. Hospital isolates of S. aureus, E. coli and P. aeruginosa displayed a relative stability of physiological properties against the effect of bacterial-fungal metabolites as opposed to museum strains. The alterations of chrono-infrastructure of biological rhythms of microorganisms by bacterial-fungal metabolites of associants reflect the intensity of the biological system, that is inevitable during the process of formation of inter-microbial interactions.

  18. Purification and subunit structure of a putative K sup + -channel protein identified by its binding properties for dendrotoxin I

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, H.; Lazdunski, M. (Centre National de la Recherche Scientifique, Nice (France))

    1988-07-01

    The binding protein for the K{sup +}-channel toxin dendrotoxin I was purified from a detergent extract of rat brain membranes. The purification procedure utilized chromatography on DEAE-Trisacryl, affinity chromatography on a dendrotoxin-I-Aca 22 column, and wheat germ agglutinin-Affigel 10 with a final 3,800- to 4,600-fold enrichment and a recovery of 8-16%. The high affinity (K{sub d}, 40-100 pM) and specificity of the binding site are retained throughout the purification procedure. Analysis of the purified material on silver-stained NaDodSO{sub 4}/polyacrylamide gel revealed three bands of M{sub r} 76,000-80,000, 38,000 and 35,000. Interestingly, the binding site for {sup 125}I-labeled mast cell degranulating peptide, another putative K{sup +}-channel ligand from bee venom, which induces long-term potentiation in hippocampus, seems to reside on the same protein complex, as both binding sites copurify through the entire purification protocol.

  19. Purification and subunit structure of a putative K+-channel protein identified by its binding properties for dendrotoxin I

    International Nuclear Information System (INIS)

    Rehm, H.; Lazdunski, M.

    1988-01-01

    The binding protein for the K + -channel toxin dendrotoxin I was purified from a detergent extract of rat brain membranes. The purification procedure utilized chromatography on DEAE-Trisacryl, affinity chromatography on a dendrotoxin-I-Aca 22 column, and wheat germ agglutinin-Affigel 10 with a final 3,800- to 4,600-fold enrichment and a recovery of 8-16%. The high affinity (K d , 40-100 pM) and specificity of the binding site are retained throughout the purification procedure. Analysis of the purified material on silver-stained NaDodSO 4 /polyacrylamide gel revealed three bands of M r 76,000-80,000, 38,000 and 35,000. Interestingly, the binding site for 125 I-labeled mast cell degranulating peptide, another putative K + -channel ligand from bee venom, which induces long-term potentiation in hippocampus, seems to reside on the same protein complex, as both binding sites copurify through the entire purification protocol

  20. Assessment of probiotic properties of lactic acid bacteria isolated from Indonesian naturally fermented milk

    Science.gov (United States)

    Jatmiko, Yoga Dwi; Howarth, Gordon S.; Barton, Mary D.

    2017-11-01

    This study aimed to characterize the probiotic properties of lactic acid bacteria from the naturally fermented milk of Indonesia, namely dangke and dadih. Fifty-one representative lactic acid bacteria belonging to the species Lactobacillus Plantarum, Lactococcus lactis subsp. lactis and Enterococcus faecium were evaluated in vitro for potential probiotic properties based on their bile salt resistance, low pH tolerance, antimicrobial activity, antibiotic susceptibility and adherence to Caco-2 colon cancer cells. In addition, bacteriocin related gene (plantaricin A), bile salt hydrolase (bsh) and mannose-specific adhesin (msa) genes in the genome of lactobacilli were also examined. None of the dangke isolates, which belonged to the species L. lactis subsp. lactis tolerated low pH. However, eight of the isolates were able to grow in the presence of bile salts. It was observed that L. plantarum strain S1.30 and SL2.7 from dadih tolerated low pH, survived bile salt concentrations and were resistant to vancomycin. Furthermore, these strains also contained bacteriocin regulating gene (plantaricin A) and msa and bsh genes in their genome. However, only the strain S1.30 exhibited optimal antimicrobial activity against the selected pathogens and was able to adhere to Caco-2 cells by up to 82.24±0.14%. Antagonistic activity of L. lactis subsp. lactis from dadih and dangke was not detected. However, 73.94±1.26% adherence to Caco-2 cells was demonstrated by L. lactis subsp. lactis strain SL3.34 sourced from dangke. These results suggest that Lactobacillus plantarum strain S1.30 associated with dadih fulfilled the in vitro probiotic criteria and could be exploited for further in vivo evaluation. In addition, dadih was an effective probiotic carrier compared to dangke.

  1. Role of nanomaterial physicochemical properties on fate and toxicity in bacteria and plants

    Science.gov (United States)

    Slomberg, Danielle

    Nanomaterials, defined as those having at least one dimension death of terrestrial plants), thus warranted. Herein, I present the evaluation of nitric oxide-releasing nanomaterial toxicity to bacteria and silica particle toxicity to plants as a function of nanomaterial physicochemical properties. Nanomaterial toxicity toward planktonic (i.e., free-floating) Pseudomonas aeruginosa and Staphylococcus aureus bacteria was evaluated as a function of scaffold size, shape, and exterior functionality using nitric oxide-releasing (NO) silica particles, dendrimers, and chitosan oligosaccharides. Improved bactericidal efficacy was observed for silica particles with decreased size and increased aspect ratio (i.e., rod-like) due to improved particle-cell interactions. Likewise, better nanomaterial-bacteria association and biocidal action was noted for more hydrophobic NO-releasing dendrimers and chitosan oligosaccharides. Planktonic bacterial killing was not dependent on chitosan molecular weight due to rapid association between the cationic scaffolds and negatively-charged bacterial cell membranes. Given the importance of nanomaterial physicochemical properties in planktonic bacterial killing, the NO-releasing scaffolds were also evaluated against clinically-relevant bacterial biofilms. Similar to planktonic studies, smaller particle sizes proved more efficient in delivering NO throughout the biofilm. Particles with rod-like shape also eradicated biofilms more effectively. The role of NO-releasing dendrimer and chitosan oligosaccharide hydrophobicity was prominent in scaffold diffusion through the biofilm and subsequent NO delivery, with hydrophobic functionalities generally exhibiting better bacterial association. Lastly, biofilm eradication was more effective for NO-releasing dendrimers exhibiting sustained NO-release compared to delivery of NO via an intial burst. Phytotoxicity and uptake of silica nanoparticles was evaluated for the plant, Arabidopsis thaliana, as a

  2. Purification and Characterization of Agarase from Marine Bacteria Acinetobacter sp. PS12B and Its Use for Preparing Bioactive Hydrolysate from Agarophyte Red Seaweed Gracilaria verrucosa.

    Science.gov (United States)

    Leema Roseline, T; Sachindra, N M

    2018-03-05

    Acinetobacter strain PS12B was isolated from marine sediment and was found to be a good candidate to degrade agar and produce agarase enzyme. The extracellular agarase enzyme from strain PS12B was purified by ammonium sulfate precipitation followed by DEAE-cellulose ion-exchange chromatography. The specific activity of the crude enzyme which was 1.52 U increased to 45.76 U, after two-stage purification, with an enzyme yield of 9.76%. Purified enzyme had a molecular mass of 24 kDa. The optimum pH and temperature for activity of purified agarase were found to be 8.0 and 40 °C, respectively. The K m and V max values for agarase were 4.69 mg/ml and 0.5 μmol/min, respectively. Treatment with EDTA reduced the agarase activity by 58% at 5 mM concentration. The enzyme activity was stimulated by the presence of Fe 2+ , Mn 2+ , and Ca2 + ions while reducing reagents (β-mercaptoethanol and dithiothreitol, DTT) enhanced its activity by 30-40%. The purified agarase exhibited tolerance to both detergents and organic solvents. Major hydrolysis products of agar were DP4 and also a mixture of longer oligosaccharides DP6 and DP7. The enzyme hydrolysed seaweed (Gracilaria verrucosa) exhibited strong antioxidant activity in vitro. Successful hydrolysis of seaweed indicates the potential use of the enzyme to produce seaweed hydrolysate having health benefits as well as the industrial application like the production of biofuels.

  3. Rapid purification of recombinant histones.

    Science.gov (United States)

    Klinker, Henrike; Haas, Caroline; Harrer, Nadine; Becker, Peter B; Mueller-Planitz, Felix

    2014-01-01

    The development of methods to assemble nucleosomes from recombinant histones decades ago has transformed chromatin research. Nevertheless, nucleosome reconstitution remains time consuming to this day, not least because the four individual histones must be purified first. Here, we present a streamlined purification protocol of recombinant histones from bacteria. We termed this method "rapid histone purification" (RHP) as it circumvents isolation of inclusion bodies and thereby cuts out the most time-consuming step of traditional purification protocols. Instead of inclusion body isolation, whole cell extracts are prepared under strongly denaturing conditions that directly solubilize inclusion bodies. By ion exchange chromatography, the histones are purified from the extracts. The protocol has been successfully applied to all four canonical Drosophila and human histones. RHP histones and histones that were purified from isolated inclusion bodies had similar purities. The different purification strategies also did not impact the quality of octamers reconstituted from these histones. We expect that the RHP protocol can be readily applied to the purification of canonical histones from other species as well as the numerous histone variants.

  4. Kinetic properties of growth of intestinal sulphate-reducing bacteria isolated from healthy mice and mice with ulcerative colitis

    Directory of Open Access Journals (Sweden)

    Ivan Kushkevych

    2017-01-01

    Full Text Available Inflammatory bowel disease including ulcerative colitis are complex multifactorial diseases of unknown aetiology. Sulphate-reducing bacteria are often associated with the occurrence of the disease. The physiological properties of intestinal sulphate-reducing bacteria including kinetic characteristic of their growth have never been reported. The aim of this research was to evaluate the presence of sulphate-reducing bacteria isolated from the intestines of mice, study their growth, calculate and compare the kinetic growth properties on the model of dextran sulphate sodium induced ulcerative colitis in the mice. The number of viable intestinal sulphate-reducing bacteria from the bowel lumen of mice with ulcerative colitis was higher (P > 0.05 by 22% at 12 h of cultivation compared with cultures of sulphate-reducing bacteria from the bowel lumen of healthy mice. The sulphate-reducing bacteria from mice with colitis also had a slightly higher generation time (14.29 h and exponential growth phase (22.24 h compared with cultures from healthy mice. The time of lag-phase was 2 × shorter (P > 0.01 in the cultures of sulphate-reducing bacteria from mice with ulcerative colitis. The described research is new and important for the prediction of the sulphate-reducing bacteria number in the gut and their rate of dissimilatory sulphate reduction. The kinetic characteristic of their growth is important for further clarification of the mechanisms of sulphate reduction and accumulation of hydrogen sulphide, which is toxic for epithelial cells of the intestine and can cause bowel diseases both in humans and animals, in particular ulcerative colitis.

  5. Diversity and functional properties of acid-tolerant bacteria isolated from tea plantation soil of Assam.

    Science.gov (United States)

    Goswami, Gunajit; Deka, Priyadarshini; Das, Pompi; Bora, Sudipta Sankar; Samanta, Ramkrishna; Boro, Robin Chandra; Barooah, Madhumita

    2017-07-01

    In this study, we report on the bacterial diversity and their functional properties prevalent in tea garden soils of Assam that have low pH (3.8-5.5). Culture-dependent studies and phospholipid fatty acid analysis revealed a high abundance of Gram-positive bacteria. Further, 70 acid-tolerant bacterial isolates characterized using a polyphasic taxonomy approach could be grouped to the genus Bacillus, Lysinibacillus, Staphylococcus, Brevundimonas, Alcaligenes, Enterobacter, Klebsiella, Escherichia, and Aeromonas. Among the 70 isolates, 47 most promising isolates were tested for their plant growth promoting activity based on the production of Indole Acetic Acid (IAA), siderophore, and HCN as well as solubilization of phosphate, zinc, and potassium. Out of the 47 isolates, 10 isolates tested positive for the entire aforesaid plant growth promoting tests and further tested for quantitative analyses for production of IAA, siderophore, and phosphate solubilization at the acidic and neutral condition. Results indicated that IAA and siderophore production, as well as phosphate solubilization efficiency of the isolates decreased significantly (P ≤ 0.05) in the acidic environment. This study revealed that low soil pH influences bacterial community structure and their functional properties.

  6. Mechanical properties of bio self-healing concrete containing immobilized bacteria with iron oxide nanoparticles.

    Science.gov (United States)

    Seifan, Mostafa; Sarmah, Ajit K; Samani, Ali Khajeh; Ebrahiminezhad, Alireza; Ghasemi, Younes; Berenjian, Aydin

    2018-03-25

    Concrete is arguably one of the most important and widely used materials in the world, responsible for the majority of the industrial revolution due to its unique properties. However, it is susceptible to cracking under internal and external stresses. The generated cracks result in a significant reduction in the concrete lifespan and an increase in maintenance and repair costs. In recent years, the implementation of bacterial-based healing agent in the concrete matrix has emerged as one of the most promising approaches to address the concrete cracking issue. However, the bacterial cells need to be protected from the high pH content of concrete as well as the exerted shear forces during preparation and hardening stages. To address these issues, we propose the magnetic immobilization of bacteria with iron oxide nanoparticles (IONs). In the present study, the effect of the designed bio-agent on mechanical properties of concrete (compressive strength and drying shrinkage) is investigated. The results indicate that the addition of immobilized Bacillus species with IONs in concrete matrix contributes to increasing the compressive strength. Moreover, the precipitates in the bio-concrete specimen were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). The characterization studies confirm that the precipitated crystals in bio-concrete specimen were CaCO 3 , while no precipitation was observed in the control sample.

  7. Uranium hexafluoride purification

    International Nuclear Information System (INIS)

    Araujo, Eneas F. de

    1986-01-01

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF 6 -HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF 6 -HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  8. A simple procedure for the purification of active fractions in aqueous extracts of plants with allelopathic properties

    Directory of Open Access Journals (Sweden)

    Fabian Borghetti

    2013-03-01

    Full Text Available Most studies conducted to test the allelopathic activity of plant parts have made use of water as solvent. However, the presence of polar, water-soluble substances, such as proteins and carbohydrates, tends to hamper the purification of active compounds. In this study, we present a simple purification procedure that separates the active fraction of the extract from the undesirable substances, thus facilitating the search for active molecules through standard chromatographic methods. Aqueous leaf extracts of three Cerrado species (Caryocar brasiliense, Qualea parviflora and Eugenia dysenterica were prepared at 5% concentration (w/v and stored at 4ºC (crude extracts. After 24 h, these solutions were filtered and freeze-dried. The powder obtained was dissolved in methanol, filtered again, evaporated and dissolved in water for bioassays (purified extracts. For the bioassays, seedlings of Sesamum indicum were grown for five days in aqueous solutions prepared from crude and purified extracts at concentrations ranging from 0.1% to 1.0% (w/v. Seedling growth in distilled water was set as a control. In comparison with the control, we found that test solutions prepared from both crude and purified extracts significantly inhibited sesame seedling growth. However, solutions prepared from purified extracts were two to ten times more inhibitory to seedling growth than were those prepared from crude extracts. The inhibition of root growth ranged from 35% to 77%, depending on the plant species, at a concentration as low as 0.1%. Roots were more affected than were shoots. The effects of purified extracts on seedling morphology were similar to those observed when crude extracts were employed, indicating that the procedure of purification of crude extracts did not interfere with the mode of action of the active substances

  9. Autoinducer-2 properties of kimchi are associated with lactic acid bacteria involved in its fermentation.

    Science.gov (United States)

    Park, Hyunjoon; Shin, Heuynkil; Lee, Kyuyeon; Holzapfel, Wilhelm

    2016-05-16

    Bacteria use the cell density-dependent quorum signalling system to regulate particular gene expressions. In food microbiology, signalling is well known for its relation to (foodborne) pathogenicity, food spoilage, and biofilm formation. Quorum quenching and inhibition are thus being considered as a feasible approach in food preservation and safety. In the case of the luxS-mediated universal quorum sensing using autoinducer-2 (AI-2), however, it could be a different issue. Several studies have reported a luxS AI-2 synthase homologue in numerous bacteria, comprising both pathogens and beneficial strains. A recent study has shown the AI-2 signal to restore the balance of the major phyla of the gut microbiota in antibiotic-induced dysbiosis. We measured the AI-2 activity of the lactic fermented food, kimchi, and found different AI-2 signalling intensities. In order to trace the origin of the signal production, we obtained 229 lactic acid bacterial isolates from the kimchi samples, and detected the AI-2 properties of each isolate using a modified AI-2 bioluminescence assay. Our results showed isolates of dominant species of the genera Lactobacillus, Weissella and Leuconostoc which either produced or inhibited the AI-2 signal. No isolate of the dominant species Lactobacillus sakei (75 isolates) and Lactobacillus curvatus (28 isolates) showed AI-2 producing activity, while AI-2 inhibition could not be detected for any of the 31 Lactobacillus plantarum isolates. These results suggest the AI-2 activity of kimchi to result from the interaction of the associated microbial food cultures (MFCs) during fermentation. Thus far, only sparse information is available on AI-2 signalling interaction in fermented food, however, we suggest that fermented food may be a supplier of AI-2 signalling molecules via typical MFCs. Copyright © 2016. Published by Elsevier B.V.

  10. Antioxidant properties of caroot juices and their impact on intestinal and probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Aleksandra Duda-Chodak

    2015-08-01

    Full Text Available There is a growing interest in non-dairy probiotic products. The main aim of the study was to evaluate the impact of juice prepared from 15 various cultivars of carrot on the growth of representatives of human intestinal microbiota (Bifidobacterium catenulatum, Escherichia coli and probiotic strains (Lactobacillus acidophilus LA-5, Lactobacillus casei 01. Carrot juice was added to liquid medium at a final concentration of 5.0% and their impact on the bacteria number was assessed by measurement of the turbidity after 24 h of culture. The number of cells was expressed as % of positive control (medium without juice addition. Juices prepared from all tested cultivars of carrot inhibited the growth of Bifidobacterium catenulatum, and the strongest inhibitory effect was observed for juices obtained from the 'Kongo F1' cultivar (3.40 ±2.85% of positive control, 'Rumba F1'(4.17 ±2.27% and 'Broker F1' (5.35 ±2.14%. The majority of tested juices also inhibited the growth of E. coli, but those prepared from the 'Niland F1', 'Napa F1', 'Afro F1'and 'Samba F1' cultivars stimulated the growth of this bacterium. The probiotic strains were less sensitive to carrot juice impact than intestinal species, however both stimulation and inhibition could be observed. Juices made from the cultivars 'Kongo F1' and 'Deep Purple F1' acted negatively on the growth of both probiotic strains, while juice from 'Bangor F1' cultivar inhibited L. casei 01 growth, but stimulated the growth of LA-5. The obtained results suggest that 'Kongo F1' and 'Deep Purple F1' cultivars are not suitable as an additive or raw material for the production of probiotic products, because of their inhibitory properties against probiotic strains. Concluding, carrots can be used as raw material for the production of probiotic beverages, however both the cultivar of carrot and the strains of probiotic bacteria used for the production should be selected carefully. The most suitable for production of

  11. Purification of trioctylphosphine oxide by liquid extracting

    International Nuclear Information System (INIS)

    Meddour, Laaldja

    1996-04-01

    Many methods of TOPO synthesis are known in the litterature. Neverthless, the purification methods still unknown or quite known. In this work, we have proposed to develop a new method of purification and we have used the extraction properties of TOPO. This method consist to extracting the molybdene with TOPO in acid medium

  12. [Screening and functional properties of cholesterol-degrading lactic acid bacteria from Jiangshui].

    Science.gov (United States)

    Li, Xueping; Li, Jianhong; Li, Minquan; Meng, Xiangang

    2015-08-04

    We intended to obtain and characterize lactic acid bacteria with high capacity of cholesterol-degrading. We chose Jiangshui as the experimental material, screened lactic acid bacteria by the culture medium with high cholesterol, and studied other features of lactic acid bacteria like salt-tolerant, acid resistance, then identified the species of lactic acid bacteria by combining physiological and biochemical methods and 16S rDNA sequence. All lactic acid bacteria isolated had the capacity of cholesterol-degrading to some extent. There were 4 strains had high cholesterol-degrading rate (> 75%). Four strains were Lactococcus lactis subsp. lactis, two were Brevibacterium casei, and one was Lactococcus raffinolactis. Cholesterol-degrading lactic acid bacteria were screened from Jiangshui, with application potential for cholesterol degradation.

  13. Assessment of probiotic properties in lactic acid bacteria isolated from wine.

    Science.gov (United States)

    García-Ruiz, Almudena; González de Llano, Dolores; Esteban-Fernández, Adelaida; Requena, Teresa; Bartolomé, Begoña; Moreno-Arribas, M Victoria

    2014-12-01

    Probiotic properties are highly strain-dependent but rarely studied in enological lactic acid bacteria (LAB). In this study, the probiotic features of 11 strains of Lactobacillus spp., Pediococcus spp., and Oenococcus oeni, including saliva and acid resistance, bile tolerance and exopolysaccharides' production, were investigated. The assays included two probiotic reference strains (Lactobacillus plantarum CLC 17 and Lactobacillus fermentum CECT5716). The Lactobacillus and Pediococcus strains showed high resistance to lysozyme (>80% resistance to 100 mg/L of lysozyme under conditions simulating the in vivo dilution by saliva) and were capable of surviving at low pH values (pH 1.8) and bile salts, suggesting good adaptation of the wine strains to gastrointestinal conditions. The ability of the strains to adhere to the intestinal mucosa and the inhibition of the adhesion of Escherichia coli to human intestinal cells were also evaluated. Adhesion levels of enological LAB to Caco-2 cells varied from 0.37% to 12.2%, depending on the strain. In particular, Pediococcus pentosaceus CIAL-86 showed a high percentage of adhesion to intestinal cells (>12%), even higher than that shown by the probiotic reference strains, and a high anti-adhesion activity against E. coli CIAL-153 (>30%), all of which support this wine LAB strain as a potential probiotic. Published by Elsevier Ltd.

  14. 130 kDa phosphatase from the liver of labeo rohita: isolation: purification and some kinetic properties

    International Nuclear Information System (INIS)

    Siddiqua, A.; Sherazi, M.; Shah, A.H.; Khan, A.R.; Khan, H.U.

    2009-01-01

    An isoenzyme of high molecular weight acid phosphatase (HM-ACP) from the live of fish rohu (Labeo Rohita) was isolated and purified to homogeneity. The enzyme had specific activity of 14.96 U/mg and a recovery of about 4%. The purification procedure included ammonium sulphate precipitation and series of chromatographic separations on SP-Sephadex C-50, CM-Cellulose and Sephacryl HR-200 columns. Nealry 500-folds purification was achieved. The molecular weight was estimated to be 120-130 kDa by polyacrylamide gel electrophoresis (PAGE) of native enzyme and 130 kDa by gel filtration on calibrated Sephadex G-100 column. sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) under reduced and non-reduced condition showed a band corresponding to 66 kDa confirming the dimeric nature of enzyme. para nitrophenyl phosphate and flavin mononucleotide were hydrolyzed effectively by the enzyme and found to be good substrates. Optimum temperature for the enzyme was 50 degree C and temperature stability was 0 degree-50 degree C. Similarly optimum ph for the enzyme was 5.4 and ph stability was 4.8-6.0. The K/sub m/ for the p-nitrophenyl phosphate was estimated to be 0.15 mM. The enzyme was competitively inhibited by the phosphate, vanadate, molybdate, tartrate, fluoride and pyridoxal-5-PO/sub 4/ while pyridoxamine-5-PO/sub 4/ showed poor inhibition. Metal ions such as Ag/sup +/, Cu/sup ++/ Zn/sup ++/ showed strong inhibition on the enzyme activity while other divalent ions like Mg/sup ++/, Mn/sup ++/ and Co/sup ++/ were found to be poor inhibitors. Modifiers like EDTA, methanol, ethanol, acetone and glycerol had no effect on the enzyme's activity. (author)

  15. Effect of lactic acid bacteria on the textural properties of an edible ...

    African Journals Online (AJOL)

    This study was aimed to evaluate the effects of different components and the addition of probiotic bacteria of lactic acid bacteria (LAB, Lactobacillus casei) on the physicochemical and textural characteristics of edible films using a response surface Box-Behnken design. The edible films were made of the following ...

  16. Effect of lactic acid bacteria on the textural properties of an edible ...

    African Journals Online (AJOL)

    Rodrigo

    2013-05-08

    May 8, 2013 ... This study was aimed to evaluate the effects of different components and the addition of probiotic bacteria of lactic acid bacteria (LAB, Lactobacillus casei) on the physicochemical and textural characteristics of edible films using a response surface Box-Behnken design. The edible films were made of the ...

  17. Nanomechanical Water Purification Device, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Seldon Laboratories, LLC, proposes a lightweight, low-pressure water purification device that harnesses the unique properties of carbon nanotubes and will operate...

  18. Bioinspired Materials for Water Purification

    Directory of Open Access Journals (Sweden)

    Alfredo Gonzalez-Perez

    2016-06-01

    Full Text Available Water scarcity issues associated with inadequate access to clean water and sanitation is a ubiquitous problem occurring globally. Addressing future challenges will require a combination of new technological development in water purification and environmental remediation technology with suitable conservation policies. In this scenario, new bioinspired materials will play a pivotal role in the development of more efficient and environmentally friendly solutions. The role of amphiphilic self-assembly on the fabrication of new biomimetic membranes for membrane separation like reverse osmosis is emphasized. Mesoporous support materials for semiconductor growth in the photocatalytic degradation of pollutants and new carriers for immobilization of bacteria in bioreactors are used in the removal and processing of different kind of water pollutants like heavy metals. Obstacles to improve and optimize the fabrication as well as a better understanding of their performance in small-scale and pilot purification systems need to be addressed. However, it is expected that these new biomimetic materials will find their way into the current water purification technologies to improve their purification/removal performance in a cost-effective and environmentally friendly way.

  19. Water Purification

    Science.gov (United States)

    1994-01-01

    The Vision Catalyst Purifier employs the basic technology developed by NASA to purify water aboard the Apollo spacecraft. However, it also uses an "erosion" technique. The purifier kills bacteria, viruses, and algae by "catalytic corrosion." A cartridge contains a silver-impregnated alumina bed with a large surface area. The catalyst bed converts oxygen in a pool of water to its most oxidative state, killing over 99 percent of the bacteria within five seconds. The cartridge also releases into the pool low levels of ionic silver and copper through a controlled process of erosion. Because the water becomes electrochemically active, no electricity is required.

  20. Introduction and comparison of measurement methods of antifungal properties of lactic acid bacteria in cheese

    Directory of Open Access Journals (Sweden)

    H Sedaghat

    2014-02-01

    Full Text Available Various laboratory methods have been developed to evaluate the effectiveness of anti-mould effect of lactic acid bacteria. However, most of these investigations have been conducted in culture medium. Due to the occurrence of complex interaction between food components and antimicrobial substances produced by lactic acid bacteria, the result achieved from these studies may be different from those seen in food model. In various studies growth inhibition of molds on the surface of foods are considered as antifungal activity. Consequently, introduction and comparison of efficient methods for evaluation of anti-mould effect of lactic acid bacteria would be helpful. In this study, antifungal activity of lactic acid bacteria inoculated in cheese was estimated using Microdilution method. Pieces of cheese samples were overlaid with molds and the antifungal effect of this bacteria was studied against Aspergillus flavus and Aspergillus parasiticus. All three methods showed the effectiveness of lactic bacteria on mold inhibition. Comparison of the results showed that there was significant positive correlation between antifungal overlay assay and direct growth of mold on cheese, since this two test showed antifungal effect in the same way including interaction between bacteria and mold and also producing antifungal compound.

  1. Interaction of gliding motion of bacteria with rheological properties of the slime.

    Science.gov (United States)

    Asghar, Z; Ali, N; Sajid, M

    2017-08-01

    Bacteria which do not have organelles of motility, such as flagella, adopt gliding as a mode of locomotion. In gliding motility bacterium moves under its own power by secreting a layer of slime on the substrate. The exact mechanism by which a glider achieves motility is yet in controversy but there are evidences which support the wave-like undulation on the surface of the organism, as a possible mechanism of motility. Based on this observation, a model of undulating sheet over a layer of slime is examined as a possible model of the gliding motion of a bacterium. Three different non-Newtonian constitutive equations namely, finite extendable nonlinear elastic-peterline (FENE-P), Simplified Phan-Thien-Tanner (SPTT) and Rabinowitsch equations are used to capture the rheological properties of the slime. It is found that the governing equation describing the fluid mechanics of the model under lubrication approximation is same for all the considered three constitutive equations. In fact, it involves a single non-Newtonian parameter which assumes different values for each of the considered constitutive relations. This differential equation is solved using both perturbation and semi-analytic procedure. The perturbation solution is exploited to get an estimate of the speed of the glider for different values of the non-Newtonian parameter. The solution obtained via semi-analytic procedure is used to investigate the important features of the flow field in the layer of the slime beneath the glider when the glider is held fixed. The expression of forces generated by the organism and power required for propulsion are also derived based on the perturbation analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Antimicrobial Activity – The Most Important Property of Probiotic and Starter Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Blaženka Kos

    2010-01-01

    Full Text Available The antimicrobial activity of industrially important lactic acid bacteria as starter cultures and probiotic bacteria is the main subject of this review. This activity has been attributed to the production of metabolites such as organic acids (lactic and acetic acid, hydrogen peroxide, ethanol, diacetyl, acetaldehyde, acetoine, carbon dioxide, reuterin, reutericyclin and bacteriocins. The potential of using bacteriocins of lactic acid bacteria, primarily used as biopreservatives, represents a perspective, alternative antimicrobial strategy for continuously increasing problem with antibiotic resistance. Another strategy in resolving this problem is an application of probiotics for different gastrointestinal and urogenital infection therapies.

  3. Antimicrobial properties of lactic acid bacteria isolated from uruguayan artisan cheese

    Directory of Open Access Journals (Sweden)

    Martín Fraga Cotelo

    2013-12-01

    Full Text Available Uruguayan artisan cheese is elaborated with raw milk and non-commercial starters. The associated native microbiota may include lactic acid bacteria and also potentially pathogenic bacteria. Lactic acid bacteria were isolated from artisan cheese, raw milk, and non-commercial starter cultures, and their potential bacteriocin production was assessed. A culture collection of 509 isolates was obtained, and five isolates were bacteriocin-producers and were identified as Enterococcus durans,Lactobacillus casei, and Lactococcus lactis. No evidence of potential virulence factors were found in E. durans strains. These are promising results in terms of using these native strains for cheese manufacture and to obtain safe products.

  4. Mutagenic effect of UV-irradiation on Alfalfa nodule bacteria and studies on symbiotic properties of the auxotrophic mutants obtained

    International Nuclear Information System (INIS)

    Fedorov, S.N.; Butvina, O.Yu.; Simarov, B.V.

    1983-01-01

    Inactivation and mutagenous effect of UV-radiation on nodula bacteria of lucerne is studied. The effect of photoreactivation is found and optimum conditions for mutagenesis are determined. A method for fast determination of effectiveness and nitrogenous activity of Rhizobium melilati mutants is determined. Using this method symbiotic properties of obtained auxotrophic mutants are determined. The dependence between the alteration of nitrogen registering activity of mutants and their aquisition of definite types of auxotrophity, is determined

  5. Purification and Physico-Chemical Properties of Milk Clotting Enzyme Produced by Mucor Lamprosporus Comparable with Calf Rennet

    International Nuclear Information System (INIS)

    Moussa, L.A.; El-Fouly, M.Z.; El-Kabbany, H.; Kamel, Z.M.; Moubasher, M.H.

    1999-01-01

    Fractional precipitation of the crude enzyme produced by Mucor Lamprosporus fungus using 70% ammonium sulfate gave the highest MCA at 40 degree. Further purification of the partially purified enzyme was achieved by using Sephadex G-100 and rechromatographed on DEAE Sephadex A-50 and gave 22.5 fold then the crude enzyme with 301% enzyme recovery. Addition of NaCl to the skim milk caused pronounced decline in MCA of the enzyme while addition of 160 ppm of NaCl increased the MCA from 26.6 su/ml to 200 su/ml. The optimum temperature of the skin milk which induced the maximum activity of the purified enzyme in skim milk was found to be 40 degree while preheating the enzyme at 50 degree for 10 min caused a complete inhibition. Mild acidic condition did not affect the activity of the purified enzyme which remained almost stable till pH 6.0 while at pH 7.0 or more, the enzyme completely lost its clotting activity. The present data also showed that Mucor Lamprosporus rennin like enzyme exhibited higher activity than calf rennet

  6. Cultural and morphological properties of the vaccine strain Yersinia pestis EV NIIEG bacteria after photodynamic inactivation

    Science.gov (United States)

    Ulianova, Onega V.; Lyapina, Anna M.; Khizhnyakova, Mariya A.; Laskavy, Vladislav N.; Feodorova, Valentina A.; Ulyanov, Sergey S.

    2015-03-01

    New method of photoinactivation of plague microbes (bacteria Yersinia pestis) has been suggested. Rate of growth of colonies of Y. pestis EV NIIEG at specific regimes of photo processing have been analyzed. Dependence of growth on exposure time and concentrations of photosensitizer (methylene blue) has been studied. Number of colony forming units of Y. pestis EV NIIEG bacteria as a function of intensity of light and concentration of methylene blue has been scrutinized.

  7. Nitroblue tetrazolium (NBT) reduction by bacteria. Some properties of the reaction and its possible use.

    Science.gov (United States)

    Urban, T; Jarstrand, C

    1979-08-01

    All the S. albus, E. coli and P. aeruginosa strains examined reduced nitroblue tetrazolium (NBT) to dark blue formazan. The amount of formazan produced was proportional to the number of bacteria. Under the same growth conditions, an equal number of bacteria of various strains produced different amounts of formazan. However, there were statistically verified differences in the NBT-reduction between the three species examined. The NBT-reduction took place in all phases of growth but was most intense in the early logarithmic phase. NBT was found to be toxic for bacteria, and the different strains had varying sensitivity to that effect. The NBT-reaction was markedly enhanced by phenazine methosulphate (PMS). The blue colour of formazan produced from NBT has an advantage over the red colour from triphenyltetrazolium chloride (TTC) if the reaction occurs in the presence of haemoglobin often present in biological materials. With NBT and PMS, 10(6)--10(7) bacteria are needed to form detectable amounts of formazan. The NBT-reduction by bacteria may be useful for measuring the influence of bactericidal, bacteriostatic or growth-stimulating factors on bacteria.

  8. Partial Purification and Characterization of Extracellular Protease ...

    African Journals Online (AJOL)

    USER

    ABSTRACT: Microbial proteases have wide industrial applications and proteases of the lactic acid bacteria (LAB) have received special attention ... Purification of the enzyme by gel filtration chromatography on Sephadex G75 following ammonium .... Gel filtration and ion exchange chromatography. The dialysate was ...

  9. Study on the Comprehensive Properties and Microstructures of A3-3 Matrix Graphite Related to the High Temperature Purification Treatment

    Directory of Open Access Journals (Sweden)

    Xiangwen Zhou

    2018-01-01

    Full Text Available At the beginning, a comparative analysis was made on the oxidation corrosion rate and ash content of A3-3 matrix graphite (MG pebbles lathed before and after high temperature purification (HTP treatment. Their oxidation corrosion rate and ash contents were almost identical, which indicated that the HTP process was to purify the entire MG pebbles and not limited on the surfaces. Furthermore, the multiple mechanical and thermal properties of MG treated without and with the treatment of HTP at ~1900°C were compared and their microstructure features were characterized as well. As the crush strength, oxidation corrosion rate, and erosion rate of MG without HTP treatment did not satisfy the specifications, the comprehensive properties and purity of MG with HTP were improved in various degrees through the HTP process so that all performances met the requirements of the A3-3 MG. The improvement of crush strength and erosion rate of MG in the HTP process could be mainly attributed to the upgradation of ordered microstructure and corresponding increase of density. However, the enhancement of oxidation corrosion rate was due to the synergistic effects of microstructural optimization and reduction of impurity elements, especially the transition metal elements of MG in the HTP process.

  10. Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment

    Directory of Open Access Journals (Sweden)

    Wang Leilei

    2008-06-01

    Full Text Available The quantitative change and size distribution of particles in the effluents from a sand filter and a granular activated carbon (GAC filter in a drinking water treatment plant were investigated. The average total concentration of particles in the sand filter effluent during a filter cycle was 148 particles/mL, 27 of which were larger than 2 µm in size. The concentration in the GAC effluent (561 particles/mL was significantly greater than that in the sand filter effluent. The concentration of particles larger than 2 µm in the GAC filter effluent reached 201 particles/mL, with the amount of particles with sizes between 2 µm and 15 µm increasing. The most probable number (MPN of carbon fines reached 43 unit/L after six hours and fines between 0.45 µm and 8.0 µm accounted for more than 50%. The total concentration of outflowing bacteria in the GAC filter effluent, 350 CFU (colony-forming units/mL, was greater than that in the sand filter effluent, 210 CFU/mL. The desorbed bacteria concentration reached an average of 310 CFU/mg fines. The disinfection efficiency of desorbed bacteria was lower than 40% with 1.5 mg/L of chlorine. The disinfection effect showed that the inactivation rate with 2.0 mg/L of chloramine (90% was higher than that with chlorine (70%. Experimental results indicated that the high particle concentration in raw water and sedimentation effluent led to high levels of outflowing particles in the sand filter effluent. The activated carbon fines in the effluent accounted for a small proportion of the total particle amount, but the existing bacteria attached to carbon fines may influence the drinking water safety. The disinfection efficiency of desorbed bacteria was lower than that of free bacteria with chlorine, and the disinfection effect on bacteria attached to carbon fines with chloramine was better than that with only chlorine.

  11. Effects of Phosphorus Solubilizing Bacteria and Nitrogen on the Qualitative and Quantitative Properties of Tuberose (Polianthes tuberosa

    Directory of Open Access Journals (Sweden)

    T. Taher

    2016-02-01

    Full Text Available Introduction: In Iran, tuberose is ranked the forth after gladiolus, rose and carnation. These flowers are known as high quality products among which maximum exportation belongs to tuberose and gladiolus. In plant cultivation and development, adequate provision of nutrients is of crucial importance. Tuberose needs plenty of nutrients to obtain the desirable quality and flowering. Hence, tuberose balanced nutrition can play an important role in increasing the yield and quality of its flowers. Nitrogen is a deciding factor for the plant growth and physiology. This nutritional element contributes to the formation of amino acids, proteins, nucleic acids and other cellular components that are required for the construction of new cells. Bio fertilizers containing phosphate solubilizing bacteria (bacillus and pseudomonas have microorganisms which are beneficial to the soil; these bacteria are conducive to the production of biological materials and as a consequence to plant development. According to a report by Rawia Eid et al., (2009 the application of phosphate solubilizing bacteria increased the growth rate of matthiola cut flower and improved its quality. In another study on soybean, it was observed that the application of phosphate solubilizing bacteria led to a rise in the plant dry matter content. Considering the contributory role of nitrogen and phosphorous in increasing the yield and quality of ornamental plants, the aim of this research was to examine the impact of different nitrogen levels and phosphate solubilizing bacteria on the yield and qualitative properties of tuberose cut flower. Materials and Methods: This research was carried out in a greenhouse in the city of Zanjan in Iran in 2011 through a factorial-form experiment based on a randomized complete block design with three replications and twelve treatments performed on tuberose double cultivar. The treatments included bio fertilizer containing phosphate solubilizing bacteria at

  12. Assessment of the in vitro bioactive properties of lactic acid bacteria isolated from native ecological niches of Ecuador.

    Science.gov (United States)

    Benavides, Ana B; Ulcuango, Mario; Yépez, Lucía; Tenea, Gabriela N

    Lactic acid bacteria are known for their biotechnological potential. In various regions of Ecuador numerous indigenous biological resources are largely undocumented. In this study, we evaluated the potential probiotic characteristics and antagonistic in vitro properties of some lactic acid bacteria from native niches of the subtropical rain forests of Ecuador. These isolates were identified according to their morphological properties, standard API50CH fermentation profile and RAPD-DNA polymorphism pattern. The selected isolates were further evaluated for their probiotic potential. The isolates grew at 15°C and 45°C, survived at a pH ranging from 2.5 to 4.5 in the presence of 0.3% bile (>90%) and grew under sodium chloride conditions. All selected isolates were sensitive to ampicillin, amoxicillin and cefuroxime and some showed resistance to gentamicin, kanamycin and tetracycline. Moreover, the agar well diffusion assay showed that the supernatant of each strain at pH 3.0 and pH 4.0, but not at pH 7.0 exhibited increased antimicrobial activity (inhibition zone >15mm) against two foodborne pathogens, Escherichia coli and Salmonella spp. To our knowledge, this is the first report describing the antagonistic activity against two foodborne pathogens and the probiotic in vitro potential of lactic acid bacteria isolated from native biota of Ecuador. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Modelling of the acid base properties of two thermophilic bacteria at different growth times

    Science.gov (United States)

    Heinrich, Hannah T. M.; Bremer, Phil J.; McQuillan, A. James; Daughney, Christopher J.

    2008-09-01

    Acid-base titrations and electrophoretic mobility measurements were conducted on the thermophilic bacteria Anoxybacillus flavithermus and Geobacillus stearothermophilus at two different growth times corresponding to exponential and stationary/death phase. The data showed significant differences between the two investigated growth times for both bacterial species. In stationary/death phase samples, cells were disrupted and their buffering capacity was lower than that of exponential phase cells. For G. stearothermophilus the electrophoretic mobility profiles changed dramatically. Chemical equilibrium models were developed to simultaneously describe the data from the titrations and the electrophoretic mobility measurements. A simple approach was developed to determine confidence intervals for the overall variance between the model and the experimental data, in order to identify statistically significant changes in model fit and thereby select the simplest model that was able to adequately describe each data set. Exponential phase cells of the investigated thermophiles had a higher total site concentration than the average found for mesophilic bacteria (based on a previously published generalised model for the acid-base behaviour of mesophiles), whereas the opposite was true for cells in stationary/death phase. The results of this study indicate that growth phase is an important parameter that can affect ion binding by bacteria, that growth phase should be considered when developing or employing chemical models for bacteria-bearing systems.

  14. The streptococcal flavoprotein NADH peroxidase: Purification, analysis of structural and redox properties, and identification of the active-site cysteinyl derivate

    Energy Technology Data Exchange (ETDEWEB)

    Poole, L.B.

    1988-01-01

    The NADH peroxidase of Streptococcus faecalis 10C1, purified to homogeneity, was studied using a variety of structural and spectroscopic techniques. The cofactor content of the enzyme was established using standard techniques, including atomic absorption analyses for the metal content. The native and subunit molecular weights of the protein were obtained through a combination of analytical ultracentrifugation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, amino acid composition, and flavin content. Redox properties were studied by spectral titrations with substrates and/or chemical reductants. An essential oxidized cysteinyl derivative within the enzyme was identified through thio titrations of oxidized and reduced enzyme with 5,5{prime}-dithiobis(2-nitrobenzoic acid), reductive alkylation of the enzyme with iodo(2-{sup 14}C)acetamide, and performic acid oxidation of enzyme labelled metabolically with ({sup 35}S)cysteine. Proteolytic digestion of radiolabelled enzyme followed by peptide purification by high performance liquid chromatography and automated Edman degradation yielded amino acid sequences of the cysteine-containing tryptic and chymotryptic peptides. Preliminary mass spectral analysis of the chymotryptic peptide was performed to probe the structure of the oxidized cysteinyl derivative.

  15. The streptococcal flavoprotein NADH peroxidase: Purification, analysis of structural and redox properties, and identification of the active-site cysteinyl derivate

    International Nuclear Information System (INIS)

    Poole, L.B.

    1988-01-01

    The NADH peroxidase of Streptococcus faecalis 10C1, purified to homogeneity, was studied using a variety of structural and spectroscopic techniques. The cofactor content of the enzyme was established using standard techniques, including atomic absorption analyses for the metal content. The native and subunit molecular weights of the protein were obtained through a combination of analytical ultracentrifugation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, amino acid composition, and flavin content. Redox properties were studied by spectral titrations with substrates and/or chemical reductants. An essential oxidized cysteinyl derivative within the enzyme was identified through thio titrations of oxidized and reduced enzyme with 5,5'-dithiobis(2-nitrobenzoic acid), reductive alkylation of the enzyme with iodo[2- 14 C]acetamide, and performic acid oxidation of enzyme labelled metabolically with [ 35 S]cysteine. Proteolytic digestion of radiolabelled enzyme followed by peptide purification by high performance liquid chromatography and automated Edman degradation yielded amino acid sequences of the cysteine-containing tryptic and chymotryptic peptides. Preliminary mass spectral analysis of the chymotryptic peptide was performed to probe the structure of the oxidized cysteinyl derivative

  16. BACTERIA STAPHYLOCOCCUS SPP. IZOLATED FROM MASTITIS OF SHEEP AND THEIR ENTEROTOXIGENIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    František Zigo

    2011-12-01

    Full Text Available In our study was followed occurrence of staphylococcal mastitis in herd of 350 sheep during one lactation season. We found, the bacteria S. schleiferi was identified in 88 from all 204 isolates. In high number were identified also S. caprae (33, S. chromogenes (21, S. aureus (19, S. epidermidis (17, respectively. Important was occurrence S. intermedius, S. simulans, S. xylosus a S. warneri, too. The Staphylococcuss spp. caused latent and subclinical forms of mastitis predominantly, showed into subacute mastitis (26.5%. Acute mastitis was determined in 7.8 %. Eight bacteria S. aureus, two S. chromogenes, and two S. epidermidis produced staphylococcal enterotoxins.doi: 10.5219/171

  17. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    Science.gov (United States)

    Najjari, Afef; Turki, Yousra; Jaballah, Sana; Boudabous, Abdelatif; Ouzari, Hadda

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota. PMID:24151598

  18. Antagonistic endophytic bacteria associated with nodules of soybean (Glycine max L.) and plant growth-promoting properties.

    Science.gov (United States)

    Zhao, LongFei; Xu, YaJun; Lai, XinHe

    2017-10-13

    A total of 276 endophytic bacteria were isolated from the root nodules of soybean (Glycine max L.) grown in 14 sites in Henan Province, China. The inhibitory activity of these bacteria against pathogenic fungus Phytophthora sojae 01 was screened in vitro. Six strains with more than 63% inhibitory activities were further characterized through optical epifluorescence microscopic observation, sequencing, and phylogenetic analysis of 16S rRNA gene, potential plant growth-promoting properties analysis, and plant inoculation assay. On the basis of the phylogeny of 16S rRNA genes, the six endophytic antagonists were identified as belonging to five genera: Enterobacter, Acinetobacter, Pseudomonas, Ochrobactrum, and Bacillus. The strain Acinetobacter calcoaceticus DD161 had the strongest inhibitory activity (71.14%) against the P. sojae 01, which caused morphological abnormal changes of fungal mycelia; such changes include fracture, lysis, formation of a protoplast ball at the end of hyphae, and split ends. Except for Ochrobactrum haematophilum DD234, other antagonistic strains showed the capacity to produce siderophore, indole acetic acid, and nitrogen fixation activity. Regression analysis suggested a significant positive correlation between siderophore production and inhibition ratio against P. sojae 01. This study demonstrated that nodule endophytic bacteria are important resources for searching for inhibitors specific to the fungi and for promoting effects for soybean seedlings. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  19. Diversity and antimicrobial properties of lactic acid bacteria isolated from rhizosphere of olive trees and desert truffles of Tunisia.

    Science.gov (United States)

    Fhoula, Imene; Najjari, Afef; Turki, Yousra; Jaballah, Sana; Boudabous, Abdelatif; Ouzari, Hadda

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota.

  20. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    Directory of Open Access Journals (Sweden)

    Imene Fhoula

    2013-01-01

    Full Text Available A total of 119 lactic acid bacteria (LAB were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota.

  1. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature

    Science.gov (United States)

    Cho, Youngjae; Hahn, Tae-Wook

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10−6 kg O3 h−1) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (prefrigerated storage. The results of this study provide a foundation for the further application of ozone exposure by integrating an ozone generator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed. PMID:26761291

  2. Lifestyle assessment of branched tetraether source bacteria via root systems of different age and properties

    Science.gov (United States)

    Huguet, Arnaud; Gocke, Martina; Wiesenberg, Guido L. B.; Fosse, Céline; Derenne, Sylvie

    2013-04-01

    Branched glycerol dialkyl glycerol tetraethers (GDGTs) are complex lipids of high molecular weight, recently discovered in soils. They were suggested to be produced by still unknown anaerobic bacteria. The relative distribution of branched GDGTs was shown to depend on environmental parameters: the degree of methylation of branched GDGTs (MBT index) likely depends on air temperature and to a lesser extent on soil pH, whereas the relative abundance of cyclopentyl rings of branched GDGTs (CBT index) correlates well with soil pH. Even though over the last years an increasing number of studies have focused on the potential use of branched GDGTs as paleoclimate proxies, the ecological niche of their source organisms remains unknown. An improved knowledge of the habitat and lifestyle of branched GDGT-producing bacteria is essential to interpret the environmental data derived from these lipids. The aim of this work was to obtain more information on branched GDGT source bacteria via the analysis of branched GDGTs in the vicinity of root systems of different age and habitat. Calcified and non-calcified living and dead roots were selected. The distribution and abundance of branched GDGTs were determined in roots and surrounding soil/sediment collected from two forest sites on fluvial sand and loess near Sopron (Hungary). Living root samples and surrounding soil were collected between 0 and 0.5 m below present surface, whereas calcified root systems (rhizoliths) were collected at 1.5 - 1.8 m depth. Reference sediment samples without visible root remains were collected 50-70 cm distant from the rhizoliths. Ancient roots (ca. 3000-yr age) and surrounding sediments were also collected at 2.2-2.6m in a loess-paleosol sequence located in Nussloch (SW Germany). In living root systems from Hungary, branched GDGTs were especially abundant in fine roots (2 mm) themselves. This suggests that branched GDGT producing bacteria are associated with the root surface and most likely feed on

  3. Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks.

    Directory of Open Access Journals (Sweden)

    Junchang Feng

    Full Text Available Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5 and bile salt (ranging from 0.1% to 1.0% conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231 and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1 were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF, IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry.

  4. Purification and Properties of a Novel Xanthan Depolymerase from a Salt-Tolerant Bacterial Culture, HD1

    Science.gov (United States)

    Hou, Ching T.; Barnabe, Nancy; Greaney, Kathy

    1986-01-01

    A novel xanthan depolymerase (endo-β-1,4-glucanase) was isolated from a salt-tolerant bacteria culture (HD1) grown on xanthan. The depolymerase was purified 55-fold through chromatography on ion-exchange and molecular sieve columns, including high-performance liquid chromatography. The purified enzyme fraction was homogeneous as judged by polyacrylamide gel electrophoresis. The molecular weight of this enzyme is 60,000. Optimum pH and temperature for xanthan depolymerase activity were around 5 and 30 to 35°C, respectively. The enzyme was not stable at a temperature higher than 45°C. The activation energy calculated from an Arrhenius plot was 6.40 kcal (26.78 kJ). The enzyme molecule contains no sugar moiety. The amino acid composition of the enzyme protein was determined. Xanthan depolymerase cleaves the endo-β-1,4-glucosidic linkage of the xanthan molecule, freeing reducing groups of some sugars and decreasing viscosity of the polymer solution. Only the backbones of β-1,4-linked glucans with side chains or other substituents were cleaved. No monosaccharide was produced by the action of this enzyme. The oligosac-charide(s) in the low-molecular weight fraction consisted of 15 to 58 monosaccharide units. The enzymic reaction resulted in the decrease in weight-average molecular weight of xanthan from 6.5 × 106 to 8.0 × 105 in 0.5 h. This enzyme alone could not degrade xanthan to a single or multiple pentasaccharide unit(s). Results suggest that there may be regions inside the xanthan molecule that are susceptible to the attack of this enzyme. Xanthan depolymerase activity was not inhibited by many chemicals, including thiols, antioxidants, chlorinated hydrocarbons, metal-chelating agents, and inorganic compounds, except ferric chloride and arsenomolybdate. Many biocides were tested and found not to be inhibitory. Conditions used in enhanced oil recovery operations, i.e., the presence of formaldehyde, Na2S2O4, 2,2-dibromo-3-nitrilopropionamide, and an anaerobic

  5. The impact of three strains of oral bacteria on the surface and mechanical properties of a dental resin material.

    Science.gov (United States)

    Gregson, Karen S; Shih, Han; Gregory, Richard L

    2012-08-01

    The purpose of this study was to determine if three strains of bacteria could impact the mechanical or surface properties of a dental resin material. Resin material specimens were incubated at 37°C in sterile saline, tryptic soy broth supplemented with sucrose (TSBS), or TSBS inoculated with Streptococcus mutans, Streptococcus gordonii, or Streptococcus sanguis. The specimens were subjected to Fourier transform infrared spectroscopy before and after incubation. The flexural strength test was performed once a week for 6 weeks. Microhardness and scanning electron microscopy (SEM) was performed on specimens at 1 and 6 weeks. Differences in the area under the carbonyl peak were statistically significant for the specimens incubated in the media inoculated with either S. mutans or S. gordonii. To determine why S. sanguis did not produce changes as the other bacteria did, triethylene glycol dimethacrylate, methacrylic acid, and triethylene glycol were added to bacterial cultures at increasing concentrations. Both methacrylic acid and triethylene glycol reduced the number of colony-forming units of S. sanguis. Specimens incubated in TSBS, saline or in culture with S. sanguis demonstrated a decrease in peak stress in week 1 of the flexure strength test. SEM demonstrated that surface topology changed for those specimens incubated in culture with S. mutans or S. gordonii. The changes in surface topology demonstrated here could contribute to the secondary caries and changes in esthetic properties seen clinically with the use of resin materials in dental restorations.

  6. Charqui meats as fermented meat products: role of bacteria for some sensorial properties development.

    Science.gov (United States)

    Pinto, M F; Ponsano, E H G; Franco, B D G M; Shimokomaki, M

    2002-06-01

    Jerked beef, a derivative of charqui meat, is a cured, salted and dried meat product. The presence of halotolerant bacteria, where Staphylococcus spp. (84.2%) were the predominant species, would act eventually as starter cultures and was followed throughout processing. Jerked beef prepared separately with exogenous S. carnosus and S. xylosus as starter cultures resulted in high proteolysis. Samples prepared with S. xylosus had the highest proteolysis and were preferred by the sensory panel. This research has suggested that jerked beef (and thus charqui meat) prepared under these conditions is a fermented meat product.

  7. Type II Collagen and Gelatin from Silvertip Shark (Carcharhinus albimarginatus Cartilage: Isolation, Purification, Physicochemical and Antioxidant Properties

    Directory of Open Access Journals (Sweden)

    Elango Jeevithan

    2014-06-01

    Full Text Available Type II acid soluble collagen (CIIA, pepsin soluble collagen (CIIP and type II gelatin (GII were isolated from silvertip shark (Carcharhinus albimarginatus cartilage and examined for their physicochemical and antioxidant properties. GII had a higher hydroxyproline content (173 mg/g than the collagens and cartilage. CIIA, CIIP and GII were composed of two identical α1 and β chains and were characterized as type II. Amino acid analysis of CIIA, CIIP and GII indicated imino acid contents of 150, 156 and 153 amino acid residues per 1000 residues, respectively. Differing Fourier transform infrared (FTIR spectra of CIIA, CIIP and GII were observed, which suggested that the isolation process affected the secondary structure and molecular order of collagen, particularly the triple-helical structure. The denaturation temperature of GII (32.5 °C was higher than that of CIIA and CIIP. The antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl radicals and the reducing power of CIIP was greater than that of CIIA and GII. SEM microstructure of the collagens depicted a porous, fibrillary and multi-layered structure. Accordingly, the physicochemical and antioxidant properties of type II collagens (CIIA, CIIP and GII isolated from shark cartilage were found to be suitable for biomedical applications.

  8. Type II Collagen and Gelatin from Silvertip Shark (Carcharhinus albimarginatus) Cartilage: Isolation, Purification, Physicochemical and Antioxidant Properties

    Science.gov (United States)

    Jeevithan, Elango; Bao, Bin; Bu, Yongshi; Zhou, Yu; Zhao, Qingbo; Wu, Wenhui

    2014-01-01

    Type II acid soluble collagen (CIIA), pepsin soluble collagen (CIIP) and type II gelatin (GII) were isolated from silvertip shark (Carcharhinus albimarginatus) cartilage and examined for their physicochemical and antioxidant properties. GII had a higher hydroxyproline content (173 mg/g) than the collagens and cartilage. CIIA, CIIP and GII were composed of two identical α1 and β chains and were characterized as type II. Amino acid analysis of CIIA, CIIP and GII indicated imino acid contents of 150, 156 and 153 amino acid residues per 1000 residues, respectively. Differing Fourier transform infrared (FTIR) spectra of CIIA, CIIP and GII were observed, which suggested that the isolation process affected the secondary structure and molecular order of collagen, particularly the triple-helical structure. The denaturation temperature of GII (32.5 °C) was higher than that of CIIA and CIIP. The antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl radicals and the reducing power of CIIP was greater than that of CIIA and GII. SEM microstructure of the collagens depicted a porous, fibrillary and multi-layered structure. Accordingly, the physicochemical and antioxidant properties of type II collagens (CIIA, CIIP) and GII isolated from shark cartilage were found to be suitable for biomedical applications. PMID:24979271

  9. Water Purification Systems

    Science.gov (United States)

    1994-01-01

    Clearwater Pool Technologies employs NASA-developed silver/copper ionization to purify turtle and dolphin tanks, cooling towers, spas, water recycling systems, etc. The pool purifier consists of a microcomputer to monitor water conditions, a pair of metallic electrodes, and a rheostat controller. Ions are generated by passing a low voltage current through the electrodes; the silver ions kill the bacteria, and the copper ions kill algae. This technology has found broad application because it offers an alternative to chemical disinfectants. It was originally developed to purify water on Apollo spacecraft. Caribbean Clear has been using NASA's silver ionization technology for water purification for more than a decade. Two new products incorporate advancements of the basic technology. One is the AquaKing, a system designed for areas with no source of acceptable drinking water. Another is the Caribbean Clear Controller, designed for commercial pool and water park applications where sanitizing is combined with feedback control of pH and an oxidizer, chlorine or bromine. The technology was originally developed to purify water on Apollo spacecraft.

  10. Exopolysaccharides from Marine and Marine Extremophilic Bacteria: Structures, Properties, Ecological Roles and Applications

    Directory of Open Access Journals (Sweden)

    Angela Casillo

    2018-02-01

    Full Text Available The marine environment is the largest aquatic ecosystem on Earth and it harbours microorganisms responsible for more than 50% of total biomass of prokaryotes in the world. All these microorganisms produce extracellular polymers that constitute a substantial part of the dissolved organic carbon, often in the form of exopolysaccharides (EPS. In addition, the production of these polymers is often correlated to the establishment of the biofilm growth mode, during which they are important matrix components. Their functions include adhesion and colonization of surfaces, protection of the bacterial cells and support for biochemical interactions between the bacteria and the surrounding environment. The aim of this review is to present a summary of the status of the research about the structures of exopolysaccharides from marine bacteria, including capsular, medium released and biofilm embedded polysaccharides. Moreover, ecological roles of these polymers, especially for those isolated from extreme ecological niches (deep-sea hydrothermal vents, polar regions, hypersaline ponds, etc., are reported. Finally, relationships between the structure and the function of the exopolysaccharides are discussed.

  11. Improving the antioxidant properties of quinoa flour through fermentation with selected autochthonous lactic acid bacteria.

    Science.gov (United States)

    Rizzello, Carlo Giuseppe; Lorusso, Anna; Russo, Vito; Pinto, Daniela; Marzani, Barbara; Gobbetti, Marco

    2017-01-16

    Lactic acid bacteria strains, previously isolated from the same matrix, were used to ferment quinoa flour aiming at exploiting the antioxidant potential. As in vitro determined on DPPH and ABTS radicals, the scavenging activity of water/salt-soluble extracts (WSE) from fermented doughs was significantly (Pquinoa dough fermented with Lactobacillus plantarum T0A10. The corresponding WSE was subjected to Reverse Phase Fast Protein Liquid Chromatography, and 32 fractions were collected and subjected to in vitro assays. The most active fraction was resistant to further hydrolysis by digestive enzymes. Five peptides, having sizes from 5 to 9 amino acid residues, were identified by nano-Liquid Chromatography-Electrospray Ionisation-Mass Spectra/Mass Spectra. The sequences shared compositional features which are typical of antioxidant peptides. As shown by determining cell viability and radical scavenging activity (MTT and DCFH-DA assays, respectively), the purified fraction showed antioxidant activity on human keratinocytes NCTC 2544 artificially subjected to oxidative stress. This study demonstrated the capacity of autochthonous lactic acid bacteria to release peptides with antioxidant activity through proteolysis of native quinoa proteins. Fermentation of the quinoa flour with a selected starter might be considered suitable for novel applications as functional food ingredient, dietary supplement or pharmaceutical preparations. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. SELECTED PROPERTIES OF LACTIC ACID BACTERIA ISOLATED FROM RAW COW'S MILK

    Directory of Open Access Journals (Sweden)

    Miroslav Kročko

    2012-02-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 For the identification of lactic acid bacteria derived from raw cow's milk, 151 colonies were isolated. The grow conditions of lactic acid bacteria were at temperature 37 °C for 3 days on MRS medium. Based on microscopical preparation, negative catalase and Gram-positive test were 81 isolates confirmed as genus Lactobacillus. Out of these, 9 isolates were evaluated for acidifying activity in UHT milk at 25 °C, 30 °C and 37 °C at regular intervals during 24 hours. The average count of NSLAB lactobacilli in raw cow's milk reached the value 1.54.104 KTJ.ml-1. It was found that all tested strains of lactobacilli did not cause significant changes of titratable acidity in milk at 25 °C and 30 °C. Only one strain significantly improved the titratable acidity of milk at 37 °C after 24 hours. The acidity reached the value from 7.5 °SH to 41.9 °SH. This strain was confirmed by PCR method as Lactobacillus helveticus.doi:10.5219/177

  13. Purification of camel liver catalase by zinc chelate affinity chromatography and pH gradient elution: An enzyme with interesting properties.

    Science.gov (United States)

    Chafik, Abdelbasset; Essamadi, Abdelkhalid; Çelik, Safinur Yildirim; Mavi, Ahmet

    2017-12-01

    Climate change and increasing temperatures are global concerns. Camel (Camelus dromedarius) lives most of its life under high environmental stress in the desert and represent ideal model for studying desert adaptation among mammals. Catalase plays a key role in protecting cells against oxidative stress. For the first time, catalase from camel liver was purified to homogeneity by zinc chelate affinity chromatography using pH gradient elution, a better separation was obtained. A purification fold of 201.81 with 1.17% yield and a high specific activity of 1132539.37U/mg were obtained. The native enzyme had a molecular weight of 268kDa and was composed of four subunits of equal size (65kDa). The enzyme showed optimal activity at a temperature of 45°C and pH 7.2. Thiol reagents, β-Mercaptoethanol and D,L-Dithiothreitol, inhibited the enzyme activity. The enzyme was inhibited by Al 3+ , Cd 2+ and Mg 2+ , whereas Ca 2+ , Co 2+ and Ni 2+ stimulated the catalase activity. Reduced glutathione has no effect on catalase activity. The K m and V max of the enzyme for hydrogen peroxide were 37.31mM and 6185157U/mg, respectively. Sodium azide inhibited the enzyme noncompetitively with K i value of 14.43μM, the IC 50 was found to be 16.71μM. The properties of camel catalase were different comparing to those of mammalian species. Relatively higher molecular weight, higher optimum temperature, protection of reduced glutathione from hydrogen peroxide oxidation and higher affinity for hydrogen peroxide and sodium azide, these could be explained by the fact that camel is able to live in the intense environmental stress in the desert. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Stimulation of the natural self-purification of soil

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, F.

    1983-01-01

    Connected with the determination of the sanitary norm of cadmium in soil, examinations were performed to appoint the self-purification index. This index is the highest permissible concentration of a noxious chemical substance in soil not yet injuring the irreversible process of natural self-purification. As criterions of the self-purification were selected normal and potential respiration, quantity of bacteria, actinomyceta, fungi, proteolytic, nitrifying, and cellulolytic micro-organisms, inhibition of Bacillus subtilis and Phormidium autumnale, survival and increasing ability of Escherichia coli, Streptococcus faecalis and Salmonella give. Among the influence of various concentrations of cadmium, the self-purification index of 500 mg Cd++/kg was determined. Offered are methodical improvements for the determination of self-purification indices.

  15. Purification of contaminated groundwater by membrane technology

    Energy Technology Data Exchange (ETDEWEB)

    Youn, In Soo; Chung, Chin Ki; Kim, Byoung Gon [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    The objective of this study is to apply the membrane separation technology to the purification of contaminated ground water in Korea. Under this scope, the purification was aimed to the drinking water level. The scale of the membrane system was chosen to a small filtration plant for local clean water supplies and/or heavy purifiers for buildings and public uses. The actual conditions of ground water contamination in Korea was surveyed to determine the major components to remove under the drinking water requirements. To set up a hybrid process with membrane methods, conventional purification methods were also investigated for the comparison purpose. The research results are summarized as follows : 1) Contamination of the groundwater in Korea has been found to be widespread across the country. The major contaminant were nitrate, bacteria, and organic chlorides. Some solvents and heavy metals are also supposed to exist in the ground water of industrial complexes, cities, and abandoned mines. 2) The purification methods currently used in public filtration plants appear not to be enough for new contaminants from recent industrial expanding. The advanced purification technologies generally adopted for this problem have been found to be unsuitable due to their very complicated design and operation, and lack of confidence in the purification performance. 3) The reverse osmosis tested with FilmTec FT30 membrane was found to remove nitrate ions in water with over 90 % efficiency. 4) The suitable membrane process for the contaminated groundwater in Korea has been found to be the treatments composed of activated carbon, microfiltration, reverse osmosis or ultrafiltration, and disinfection. The activated carbon treatment could be omitted for the water of low organic contaminants. The microfiltration and the reverse osmosis treatments stand for the conventional methods of filtration plants and the advanced methods for hardly removable components, respectively. It is recommended

  16. Purification of a beta-galactosidase from cotyledons of Hymenaea courbaril L. (Leguminosae). Enzyme properties and biological function.

    Science.gov (United States)

    de Alcântara, P H N; Martim, L; Silva, C O; Dietrich, S M C; Buckeridge, M S

    2006-01-01

    Beta-galactosidases are enzymes that can be found in most living beings and in the plant kingdom its activity and genes have been detected in several tissues such as ripening fruits, developing leaves and flowers and storage tissues such as cotyledons. In plants, their activities are usually associated with the secondary metabolism or with oligosaccharide or polysaccharide degradation. Polysaccharide specific beta-galactosidases include beta-galactanases, which attack pectic polymers and beta-galactosidases that attack xyloglucans (XG). In the present work we purified an XG-specific beta-galactosidase (named hcbetagal) from cotyledons of developing seedlings of Hymenaea courbaril, a legume tree from the Neotropical region of the world. The enzyme has a molecular weight of 52-62 kDa and was shown to attack specifically xyloglucan oligosaccharides (XGOs) but not the polymer. It has a pH optimum between 3 and 4 and at this pH range the enzyme increases activity linearly up to 50 degrees C. Kinetic studies showed that hcbetagal is inhibited competitively by free galactose (K(i) = 3.7). The biochemical properties of hcbetagal as a whole suggest that it is involved in storage xyloglucan mobilisation during seedling development. Its high specificity towards XGOs, the low pH optimum and the fact that it is inhibited by its product (galactose) suggest that hcbetagal might be one of the biochemical control points in xyloglucan catabolism in vivo. A possible relationship with functional stability of the wall during cell death as cotyledons undergo senescence is discussed.

  17. Differential effects of dissolved organic carbon upon re-entrainment and surface properties of groundwater bacteria and bacteria-sized microspheres during transport through a contaminated, sandy aquifer

    Science.gov (United States)

    Harvey, R.W.; Metge, D.W.; Mohanram, A.; Gao, X.; Chorover, J.

    2011-01-01

    Injection-and-recovery studies involving a contaminated, sandy aquifer (Cape Cod, Massachusetts) were conducted to assess the relative susceptibility for in situ re-entrainment of attached groundwater bacteria (Pseudomonas stuzeri ML2, and uncultured, native bacteria) and carboxylate-modified microspheres (0.2 and 1.0 μm diameters). Different patterns of re-entrainment were evident for the two colloids in response to subsequent injections of groundwater (hydrodynamic perturbation), deionized water (ionic strength alteration), 77 μM linear alkylbenzene sulfonates (LAS, anionic surfactant), and 76 μM Tween 80 (polyoxyethylene sorbitan monooleate, a very hydrophobic nonionic surfactant). An injection of deionized water was more effective in causing detachment of micrsopheres than were either of the surfactants, consistent with the more electrostatic nature of microsphere’s attachment, their extreme hydrophilicity (hydrophilicity index, HI, of 0.99), and negative charge (zeta potentials, ζ, of −44 to −49 mv). In contrast, Tween 80 was considerably more effective in re-entraining the more-hydrophobic native bacteria. Both the hydrophilicities and zeta potentials of the native bacteria were highly sensitive to and linearly correlated with levels of groundwater dissolved organic carbon (DOC), which varied modestly from 0.6 to 1.3 mg L−1. The most hydrophilic (0.52 HI) and negatively charged (ζ −38.1 mv) indigenous bacteria were associated with the lowest DOC. FTIR spectra indicated the latter community had the highest average density of surface carboxyl groups. In contrast, differences in groundwater (DOC) had no measurable effect on hydrophilicity of the bacteria-sized microspheres and only a minor effect on their ζ. These findings suggest that microspheres may not be very good surrogates for bacteria in field-scale transport studies and that adaptive (biological) changes in bacterial surface characteristics may need to be considered where there is longer

  18. Phenotypic identification and technological properties of lactic acid bacteria isolated from traditionally processed fish products of the Eastern Himalayas.

    Science.gov (United States)

    Thapa, Namrata; Pal, Joydeb; Tamang, Jyoti Prakash

    2006-03-01

    Sukako maacha, gnuchi, sidra and sukuti are traditional smoked and sun-dried fish products of the Eastern Himalayan regions of Nepal and India. A total of 40 samples of sukako maacha (14), gnuchi (6), sidra (10) and sukuti (10) were collected and were analysed for microbial load. Population of lactic acid bacteria (LAB) as well as aerobic mesophilic counts ranged from 4.7-8.3 to 5.1-8.5 log cfu g(-1), respectively. A total of 189 strains of LAB were isolated from sukako maacha, gnuchi, sidra and sukuti samples, out of which 171 strains were cocci and 15 strains, were heterofermentative lactobacilli. LAB were identified on the basis of phenotypic characters including API system as Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus plantarum, Leuconostoc mesenteroides, Enterococcus faecium, Enterococcus faecalis, Pediococcus pentosaceus and Weissella confusa. LAB strains produced a wide spectrum of enzymes. Some strains of LAB showed antagonistic properties against pathogenic strains. None of the strains produced biogenic amines in the method applied. This paper is the first report on the microbial composition, mostly lactic acid bacteria, of traditionally processed fish products of Eastern Himalayas.

  19. Purification of phage display-modified bacteriophage T4 by affinity chromatography

    Directory of Open Access Journals (Sweden)

    Figura Grzegorz

    2011-05-01

    Full Text Available Abstract Background Affinity chromatography is one of the most efficient protein purification strategies. This technique comprises a one-step procedure with a purification level in the order of several thousand-fold, adaptable for various proteins, differentiated in their size, shape, charge, and other properties. The aim of this work was to verify the possibility of applying affinity chromatography in bacteriophage purification, with the perspective of therapeutic purposes. T4 is a large, icosahedral phage that may serve as an efficient display platform for foreign peptides or proteins. Here we propose a new method of T4 phage purification by affinity chromatography after its modification with affinity tags (GST and Histag by in vivo phage display. As any permanent introduction of extraneous DNA into a phage genome is strongly unfavourable for medical purposes, integration of foreign motifs with the phage genome was not applied. The phage was propagated in bacteria expressing fusions of the phage protein Hoc with affinity tags from bacterial plasmids, independently from the phage expression system. Results Elution profiles of phages modified with the specific affinity motifs (compared to non-specific phages document their binding to the affinity resins and effective elution with standard competitive agents. Non-specific binding was also observed, but was 102-105 times weaker than the specific one. GST-modified bacteriophages were also effectively released from glutathione Sepharose by proteolytic cleavage. The possibility of proteolytic release was designed at the stage of expression vector construction. Decrease in LPS content in phage preparations was dependent on the washing intensity; intensive washing resulted in preparations of 11-40 EU/ml. Conclusions Affinity tags can be successfully incorporated into the T4 phage capsid by the in vivo phage display technique and they strongly elevate bacteriophage affinity to a specific resin. Affinity

  20. Identification of organic acids in Cichorium intybus inhibiting virulence-related properties of oral pathogenic bacteria

    NARCIS (Netherlands)

    Papetti, A.; Mascherpa, D.; Carazzone, C.; Stauder, M.; Spratt, D.A.; Wilson, M.; Pratten, J.; Ciric, L.; Lingström, P.; Zaura, E.; Weiss, E.; Ofek, I.; Signoretto, C.; Pruzzo, C.; Gazzani, G.

    2013-01-01

    The low molecular mass (LMM) extract of Cichorium intybus var. silvestre (red chicory) has been shown to inhibit virulence-linked properties of oral pathogens including Streptococcus mutans, Actinomyces naeslundii and Prevotella intermedia. In the present study HPLC-DAD-ESI/MS2 was used to

  1. Intrinsic properties of so-called dormant probiotic bacteria, determined by flow cytometric viability assays.

    Science.gov (United States)

    Lahtinen, Sampo J; Ouwehand, Arthur C; Reinikainen, Johanna P; Korpela, Jaakko M; Sandholm, Jouko; Salminen, Seppo J

    2006-07-01

    Plate counting and four culture-independent flow cytometric assays were used to determine the viability and intrinsic properties of three probiotic strains during storage. The strains showed reduction in plate counts but were able to maintain esterase activity, intact cytoplasmic membrane, and pH gradient. The apparently uncultivable probiotic cells were active and stress resistant.

  2. Intrinsic Properties of So-Called Dormant Probiotic Bacteria, Determined by Flow Cytometric Viability Assays

    OpenAIRE

    Lahtinen, Sampo J.; Ouwehand, Arthur C.; Reinikainen, Johanna P.; Korpela, Jaakko M.; Sandholm, Jouko; Salminen, Seppo J.

    2006-01-01

    Plate counting and four culture-independent flow cytometric assays were used to determine the viability and intrinsic properties of three probiotic strains during storage. The strains showed reduction in plate counts but were able to maintain esterase activity, intact cytoplasmic membrane, and pH gradient. The apparently uncultivable probiotic cells were active and stress resistant.

  3. Probiotic properties and safety assessment of lactic acid bacteria isolated from kajmak

    Directory of Open Access Journals (Sweden)

    Rajković, J.

    2015-12-01

    Full Text Available One hundred forty-one strains of lactic acid bacteria (LAB were tested for probiotic features such as antimicrobial activities, autoaggregation ability, hydrophobicity of bacterial cell walls and ability to grow on and hydrolyze bile salts. Additionally, resistance to antibiotics and production of biogenic amines were performed as safety assessment of LAB strains. Five Lc. lactis ssp. lactis and six Lc. raffinolactis strains showed antibacterial activities against used indicator strains. Protein nature of antibacterial compounds was proven by the addition of pronase. Enterococcus durans strains had the highest degree of autoaggregation and hydrophobicity while the rest of the strains showed low degree for both characteristics. Lb. paracasei, Lb. plantarum, Ln. mesenteroides, En. faecium, En. faecalis and En. durans strains could growth on bile salts and some of them were able to hydrolyse them. Safety assessment of LAB indicates that many strains of enterococci were resistant to chloramphenicol, tetracycline, cephalosporin and to the lowest used concentration of erythromycin. The strains from other LAB genera were resistant to antibiotics used in lower concentration and in smaller numbers when compared to enterococci.

  4. Properties of Kimchi Fermented with GABA-Producing Lactic Acid Bacteria as a Starter.

    Science.gov (United States)

    Lee, Kang Wook; Shim, Jae Min; Yao, Zhuang; Kim, Jeong A; Kim, Jeong Hwan

    2018-02-13

    Kimchi was prepared with a starter, Lactobacillus zymae GU240 producing γ-aminobutyric acid (GABA), and one precursor of GABA (glutamic acid, glutamic acid mono sodium salt (MSG), or kelp extract). L. zymae GU240, an isolate from kimchi, can grow at 7% NaCl and low temperature. Five different kimchi samples were fermented for 20 weeks at -1°C. Kimchi with starter alone could not produce GABA. GABA content was highest in kimchi with co-inoculation of starter and MSG (1%, w/w). Kimchi co-inoculated with a starter and kelp extract powder (3%, w/w) had the second highest GABA content. Addition of glutamic acid powder (1%, w/w) caused a reduction in the pH level of kimchi and growth inhibition of lactic acid bacteria (LAB) and yeasts. Kimchi samples with MSG or kelp extract showed improvement of sensory evaluation scores. The results demonstrate the possibility to produce kimchi with improved functionality and taste by using L. zymae GU240 as a starter along with a suitable precursor such as MSG or kelp extract.

  5. [The study of mycolytic properties of aerobic spore-forming bacteria producing extracellular chitinases].

    Science.gov (United States)

    Aktuganov, G E; Melent'ev, A I; Galimzianova, N F; Shirokov, A V

    2008-01-01

    The mycolytic activity of 27 strains of antagonistic bacilli belonging to two taxonomic groups (18 strains of Bacillus subtilis and 9 strains of Paenibacillus ehimensis) capable of induced synthesis of chitinolytic enzymes was studied. Most of the B. subtilis strains neither displayed visible mycolytic effects on the phytopathogenic fungus Bipolaris sorokiniana in vitro, nor produced chitinases in the presence of an auto-claved mycelium. On the contrary, P. ehimensis strains grown under conditions favorable for induction of chitinases and other hydrolases exhibited a pronounced lytic effect on B. sorokiniana and actively grew by utilizing mycelium as the sole source of carbon and nitrogen. Comparison of the mycolytic activities of extracellular hydrolases in the studied strains demonstrated low correlation between chitinase production and the ability of the strains to degrade the cell walls of B. sorokiniana. Characterization of enzyme profiles in the studied strains revealed that beta-1,3-glucanase was a more significant factor than chitinase for determining the mycolytic potential of bacteria and their ability to utilize the mycelium of phytopathogenic fungi as a growth substrate.

  6. Immunomodulatory properties of fermented soy and dairy milks prepared with lactic acid bacteria.

    Science.gov (United States)

    Wagar, L E; Champagne, C P; Buckley, N D; Raymond, Y; Green-Johnson, J M

    2009-10-01

    Fermented soy and dairy milk preparations provide a means for delivering lactic acid bacteria and their fermentation products into the diet. Our aims were to test immunomodulatory bioactivity of fermented soy beverage (SB) and dairy milk blend (MB) preparations on human intestinal epithelial cells (IEC) and to determine the impact of freezing medium on culture survival prior to bioactivity analyses. Fermented SB and MB were prepared using pure or mixed cultures of Streptococcus thermophilus ST5, Bifidobacterium longum R0175, and Lactobacillus helveticus R0052. Immunomodulatory bioactivity was assessed by testing selected SB and MB ferments on tumor necrosis factor alpha (TNFalpha)-treated IEC and measuring effects on Interleukin-8 (IL-8) production. Impact of timing of ferment administration relative to this pro-inflammatory challenge was investigated. The most pronounced reductions in IEC IL-8 production were observed when IEC were treated with either SB or MB ferment preparations prior to TNFalpha challenge. These results indicate that freezing-stable MB and SB ferments prepared with selected strains can modulate IEC IL-8 production in vitro, and suggest that yogurt-like fermented soy formulations could provide a functional food alternative to milk-based fermented products.

  7. Chromium (VI) biosorption properties of multiple resistant bacteria isolated from industrial sewerage.

    Science.gov (United States)

    Oyetibo, Ganiyu Oladunjoye; Ilori, Matthew Olusoji; Obayori, Oluwafemi Sunday; Amund, Olukayode Oladipo

    2013-08-01

    Chromium (VI) [Cr (VI)] biosorption by four resistant autochthonous bacterial strains was investigated to determine their potential for use in sustainable marine water-pollution control. Maximum exchange between Cr (VI) ions and protons on the cells surfaces were at 30-35 °C, pH 2.0 and 350-450 mg/L. The bacterial strains effectively removed 79.0-90.5 % Cr (VI) ions from solution. Furthermore, 85.3-93.0 % of Cr (VI) ions were regenerated from the biomasses, and 83.4-91.7 % of the metal was adsorbed when the biomasses was reused. Langmuir isotherm performed better than Freundlich isotherm, depicting that Cr (VI) affinity was in the sequence Rhodococcus sp. AL03Ni > Burkholderia cepacia AL96Co > Corynebacterium kutscheri FL108Hg > Pseudomonas aeruginosa CA207Ni. Biosorption isotherms confirmed that Rhodococcus sp. AL03Ni was a better biosorbent with a maximum uptake of 107.46 mg of Cr (VI) per g (dry weight) of biomass. The results highlight the high potential of the organisms for bacteria-based detoxification of Cr (VI) via biosorption.

  8. Nanoscopic Vibrations of Bacteria with Different Cell-Wall Properties Adhering to Surfaces under Flow and Static Conditions

    NARCIS (Netherlands)

    Song, Lei; Sjollema, Jelmer; Sharma, Prashant K.; Kaper, Hans J.; van der Mei, Henny C.; Busscher, Henk J.

    Bacteria adhering to surfaces demonstrate random, nanoscopic vibrations around their equilibrium positions. This paper compares vibrational amplitudes of bacteria adhering to glass. Spring constants of the bond are derived from vibrational amplitudes and related to the electrophoretic softness of

  9. Reconstructed Ancestral Enzymes Impose a Fitness Cost upon Modern Bacteria Despite Exhibiting Favourable Biochemical Properties.

    Science.gov (United States)

    Hobbs, Joanne K; Prentice, Erica J; Groussin, Mathieu; Arcus, Vickery L

    2015-10-01

    Ancestral sequence reconstruction has been widely used to study historical enzyme evolution, both from biochemical and cellular perspectives. Two properties of reconstructed ancestral proteins/enzymes are commonly reported--high thermostability and high catalytic activity--compared with their contemporaries. Increased protein stability is associated with lower aggregation rates, higher soluble protein abundance and a greater capacity to evolve, and therefore, these proteins could be considered "superior" to their contemporary counterparts. In this study, we investigate the relationship between the favourable in vitro biochemical properties of reconstructed ancestral enzymes and the organismal fitness they confer in vivo. We have previously reconstructed several ancestors of the enzyme LeuB, which is essential for leucine biosynthesis. Our initial fitness experiments revealed that overexpression of ANC4, a reconstructed LeuB that exhibits high stability and activity, was only able to partially rescue the growth of a ΔleuB strain, and that a strain complemented with this enzyme was outcompeted by strains carrying one of its descendants. When we expanded our study to include five reconstructed LeuBs and one contemporary, we found that neither in vitro protein stability nor the catalytic rate was correlated with fitness. Instead, fitness showed a strong, negative correlation with estimated evolutionary age (based on phylogenetic relationships). Our findings suggest that, for reconstructed ancestral enzymes, superior in vitro properties do not translate into organismal fitness in vivo. The molecular basis of the relationship between fitness and the inferred age of ancestral LeuB enzymes is unknown, but may be related to the reconstruction process. We also hypothesise that the ancestral enzymes may be incompatible with the other, contemporary enzymes of the metabolic network.

  10. Study of bacteria Gluconobacter sp.: isolation, purification, phenotypic and molecular identification Estudo de bactérias do gênero Gluconobacter: isolamento, purificação, identificação fenotípica e molecular

    Directory of Open Access Journals (Sweden)

    André Luiz Dorini de Oliveira

    2010-03-01

    Full Text Available The importance of the study of acetic bacteria, on species of the Gluconobacter genus is based on its industrial application, as these possess the capacity of bioconversion of sorbitol to sorbose, enabling the process of vitamin C production. The study involved samples collected in industries of soft drinks, flowers, fruits and honey, followed by purification, phenotypic identification, molecular identification with the use of primer defined from Nucleotide Sequence Database consultation. Strains preserved were identified as members of the Acetobacteraceae family, Gluconobacter genus. 110 strains had been isolated of substrate: Pyrostegia venusta (ker-gawler, honey, Vitis vinifera (grape, Pyrus communis (pear, Malus sp. (apple and in two samples of soft drinks. Of this total 57 strains had been recovered in manitol medium (manitol, yeast extract, peptone, 12 in YMG medium (glucose, manitol, yeast extract, ethanol, acetic acid, 41 in enrichment medium (De Ley and Swings and later in the GYC medium (glucose, yeast extract and calcium carbonate. 68 strains were identified as Gram negative bacilli rods. Of these, 31 were characterized biochemically as belonging to the Acetobacteriaceae family as they were catalase positive, oxidase negative and producers of acid from glucose. The characterization of these strains was complemented with the biochemistry tests: gelatin liquefaction, nitrate reduction, indole and H2S production, oxidation of ethanol to acetic acid and molecular tests for genus identification. Only eight strains were characterized as pertaining to the Gluconobacter genus. The strains are maintained in collection cultures at the Microbiology Laboratory of the Biology Department at the São Paulo State University (UNESP in Assis, stored in malt extract at -196 ºC.A importância do estudo de bactérias acéticas, em especial as do gênero Gluconobacter, está baseada em suas aplicações industriais, pois estas possuem a capacidade de

  11. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature.

    Science.gov (United States)

    Cho, Youngjae; Muhlisin; Choi, Ji Hye; Hahn, Tae-Wook; Lee, Sung Ki

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10(-6) kg O3 h(-1)) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (pOzone exposure reduced (pozone had no clear effect. Ozone exposure increased the TBARS values during 1 to 3 d of storage (pozone exposure until 2 and 3 d of storage, respectively. This study provides information about the use of ozone exposure as an antimicrobial agent for meat under refrigerated storage. The results of this study provide a foundation for the further application of ozone exposure by integrating an ozone generator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed.

  12. Milk fat globule membrane glycoproteins: Valuable ingredients for lactic acid bacteria encapsulation?

    Science.gov (United States)

    Guerin, Justine; Burgain, Jennifer; Gomand, Faustine; Scher, Joël; Gaiani, Claire

    2017-10-04

    The membrane (Milk Fat Globule Membrane - MFGM) surrounding the milk fat globule is becoming increasingly studied for its use in food applications due to proven nutritional and technological properties. This review focuses first on current researches which have been led on the MFGM structure and composition and also on laboratory and industrial purification and isolation methods developed in the last few years. The nutritional, health benefits and techno-functional properties of the MFGM are then discussed. Finally, new techno-functional opportunities of MFGM glycoproteins as a possible ingredient for Lactic Acid Bacteria (LAB) encapsulation are detailed. The ability of MFGM to form liposomes entrapping bioactive compounds has been already demonstrated. One drawback is that liposomes are too small to be used for bacteria encapsulation. For the first time, this review points out the numerous advantages to use MFGM glycoproteins as a protecting, encapsulating matrix for bacteria and especially for LAB.

  13. Probiotic Properties of Lactic Acid Bacteria Isolated from Croatian Fresh Soft Cheese and Serbian White Pickled Cheese

    Directory of Open Access Journals (Sweden)

    Ksenija Uroić

    2014-01-01

    Full Text Available The aim of this study is to gain insight into the probiotic potential of autochthonous lactic acid bacteria (LAB isolated from artisanal fresh soft and white pickled cheeses. Eleven out of 86 LAB isolates from traditionally produced artisanal fresh soft and white pickled cheeses which survived the most rigorous simulated gastrointestinal tract conditions and did not show resistance to antibiotics were subjected to further evaluation for functional probiotic properties. The ability of the examined strains to assimilate cholesterol in the presence of bile salts was strain dependent, with the highest percentage of cholesterol assimilated by strain Lactobacillus brevis BGGO7-28 possessing S-layer proteins on its cell surface. The growth of strains with mannitol or lactulose as the only carbon source was better than with fructooligosaccharides (FOS and inulin as prebiotic substrates, which should be considered in the production of synbiotics. Moreover, the results demonstrated that the strains were highly adhesive to human enterocyte-like Caco-2 cells and to a lesser extent to HT29-MTX cells, with the exception of strain Lb. brevis BGGO7-28, which showed similar percentage of adhesion to both cell lines. This strain was the only one with the acidic cell surface, while other examined strains have the cell surfaces with electron donor and basic properties. In addition, all selected strains decreased the proliferation of gut-associated lymphoid tissue (GALT cells, suggesting possible immunomodulatory potential of the isolates. Finally, the number of viable cells in dry active preparations after lyophilisation depended on the lyoprotectant used (inulin, FOS or skimmed milk, as well as on the strain subjected to lyophilisation. In conclusion, the results obtained in this study demonstrate that particular dairy LAB isolates exhibit strain-specific probiotic properties. Thus, they could be further examined as part of mixed autochthonous starter cultures for

  14. Identification of organic acids in Cichorium intybus inhibiting virulence-related properties of oral pathogenic bacteria.

    Science.gov (United States)

    Papetti, Adele; Mascherpa, Dora; Carazzone, Chiara; Stauder, Monica; Spratt, David A; Wilson, Michael; Pratten, Jonathan; Ciric, Lena; Lingström, Peter; Zaura, Egija; Weiss, Ervin; Ofek, Itzak; Signoretto, Caterina; Pruzzo, Carla; Gazzani, Gabriella

    2013-06-01

    The low molecular mass (LMM) extract of Cichorium intybus var. silvestre (red chicory) has been shown to inhibit virulence-linked properties of oral pathogens including Streptococcus mutans, Actinomyces naeslundii and Prevotella intermedia. In the present study HPLC-DAD-ESI/MS(2) was used to investigate the compounds contained in this extract for their anti-virulence activity. The extract contained a number of components, including oxalic, succinic, shikimic and quinic acids, which interfere with the growth and virulence traits (i.e., biofilm formation, adherence to epithelial cells and hydroxyapatite) of oral pathogens involved in gingivitis and tooth decay. Succinic and quinic acid seem to be the most potent, mainly by interfering with the ability of oral pathogens to form biofilms (either through inhibition of their development or promotion of their disruption). Our findings suggest that one or more of these compounds may modulate plaque formation in vivo, which is a prerequisite for the development of both caries and gingivitis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Probiotic properties of lactic acid bacteria isolated from water-buffalo mozzarella cheese.

    Science.gov (United States)

    Jeronymo-Ceneviva, Ana Beatriz; de Paula, Aline Teodoro; Silva, Luana Faria; Todorov, Svetoslav Dimitrov; Franco, Bernadette Dora G Mello; Penna, Ana Lúcia B

    2014-12-01

    This study evaluated the probiotic properties (stability at different pH values and bile salt concentration, auto-aggregation and co-aggregation, survival in the presence of antibiotics and commercial drugs, study of β-galactosidase production, evaluation of the presence of genes encoding MapA and Mub adhesion proteins and EF-Tu elongation factor, and the presence of genes encoding virulence factor) of four LAB strains (Lactobacillus casei SJRP35, Leuconostoc citreum SJRP44, Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and Leuconostoc mesenteroides subsp. mesenteroides SJRP58) which produced antimicrobial substances (antimicrobial peptides). The strains survived the simulated GIT modeled in MRS broth, whole and skim milk. In addition, auto-aggregation and the cell surface hydrophobicity of all strains were high, and various degrees of co-aggregation were observed with indicator strains. All strains presented low resistance to several antibiotics and survived in the presence of commercial drugs. Only the strain SJRP44 did not produce the β-galactosidase enzyme. Moreover, the strain SJRP57 did not show the presence of any genes encoding virulence factors; however, the strain SJRP35 presented vancomycin resistance and adhesion of collagen genes, the strain SJRP44 harbored the ornithine decarboxylase gene and the strain SJRP58 generated positive results for aggregation substance and histidine decarboxylase genes. In conclusion, the strain SJRP57 was considered the best candidate as probiotic cultures for further in vivo studies and functional food products development.

  16. Antibacterial properties of biosurfactants against selected Gram-positive and -negative bacteria.

    Science.gov (United States)

    Díaz De Rienzo, Mayri A; Stevenson, Paul; Marchant, Roger; Banat, Ibrahim M

    2016-01-01

    The antibacterial properties and ability to disrupt biofilms of biosurfactants (rhamnolipids, sophorolipids) and sodium dodecyl sulphate (SDS) in the presence and absence of selected organic acids were investigated. Pseudomonas aeruginosa PAO1 was inhibited by sophorolipids and SDS at concentrations >5% v/v, and the growth of Escherichia coli NCTC 10418 was also inhibited by sophorolipids and SDS at concentrations >5% and 0.1% v/v, respectively. Bacillus subtilis NCTC 10400 was inhibited by rhamnolipids, sophorolipids and SDS at concentrations >0.5% v/v of all three; the same effect was observed with Staphylococcus aureus ATCC 9144. The ability to attach to surfaces and biofilm formation of P. aeruginosa PAO1, E. coli NCTC 10418 and B. subtilis NCTC 10400 was inhibited by sophorolipids (1% v/v) in the presence of caprylic acid (0.8% v/v). In the case of S. aureus ATCC 9144, the best results were obtained using caprylic acid on its own. It was concluded that sophorolipids are promising compounds for the inhibition/disruption of biofilms formed by Gram-positive and Gram-negative microorganisms and this activity can be enhanced by the presence of booster compounds such as caprylic acid. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Probiotic properties of lactic acid bacteria isolated from traditionally fermented Xinjiang cheese* #

    Science.gov (United States)

    Azat, Ramila; Liu, Yan; Li, Wei; Kayir, Abdurihim; Lin, Ding-bo; Zhou, Wen-wen; Zheng, Xiao-dong

    2016-01-01

    Six lactic acid bacterial (LAB) strains were isolated from traditionally fermented Xinjiang cheese and evaluated for functional and probiotic properties and potentials as starter cultures. The isolated six LAB strains comprised Lactobacillus rhamnosus (one strain), Lactobacillus helveticus (one strain), and Enterococcus hirae (four strains). All of the six strains were tolerant to acidic and bile salt conditions. Among which, the L. rhamnosus R4 strain showed more desirable antimicrobial, auto-aggregation, and hydrophobic activity. In addition, the strain L. rhamnosus R4 exhibited the highest level of free radical scavenging activity (53.78% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and 45.79% of hydroxyl radicals). L. rhamnosus R4 also demonstrated cholesterol and triglyceride degradation by 50.97% and 28.92%, respectively. To further examine the health-promoting effects of these LAB strains on host lifespan, Caenorhabditis elegans was used as an in vivo model. Worms fed LAB as a food source had significant differences in lifespan compared to those fed Escherichia coli OP50 (as a negative control). Feeding of L. rhamnosus R4 extended the mean lifespan of C. elegans by up to 36.1% compared to that of the control. The results suggest that the strains isolated from Xinjiang fermented dairy products have high potential as starter cultures in the cheese industry. PMID:27487805

  18. The Borexino purification system

    Science.gov (United States)

    Benziger, Jay

    2014-05-01

    Purification of 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system of combined distillation, water extraction, gas stripping and filtration. The purification system removed K, U and Th by distillation of the pseudocumene solvent and the PPO fluor. Noble gases, Rn, Kr and Ar were removed by gas stripping. Distillation was also employed to remove optical impurities and reduce the attenuation of scintillation light. The success of the purification system has facilitated the first time real time detection of low energy solar neutrinos.

  19. Surface processes during purification of InP quantum dots

    Directory of Open Access Journals (Sweden)

    Natalia Mordvinova

    2014-08-01

    Full Text Available Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good optical properties. Two methods of purification were compared and the surface processes which occur during purification were studied. Traditional precipitation with acetone is accompanied by a small increase in photoluminescence. It occurs that during the purification the hydrolysis of the indium precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH3 during the low temperature synthesis was explained. Purification of quantum dots is a very significant part of postsynthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new method of purification, electrophoresis, is investigated and described in particular.

  20. Gel purification of RNA.

    Science.gov (United States)

    Nilsen, Timothy W

    2013-02-01

    For many applications, including size selection of RNAs and purification of in vitro transcription products, it is necessary to purify RNAs on a denaturing gel. This procedure describes how to purify transcripts that have been synthesized in vitro. It is useful for labeled or unlabeled RNAs when sufficient mass is present. It can also be used to isolate small RNAs. In general, RNA purification by denaturing gel electrophoresis is practical only when the size of the desired RNA is 600 nucleotides or less.

  1. Physio-chemical, microbiological properties of tempoyak and molecular characterisation of lactic acid bacteria isolated from tempoyak.

    Science.gov (United States)

    Chuah, Li-Oon; Shamila-Syuhada, Ahamed Kamal; Liong, Min Tze; Rosma, Ahmad; Thong, Kwai Lin; Rusul, Gulam

    2016-09-01

    This study aims to determine physio-chemical properties of tempoyak, characterise the various indigenous species of lactic acid bacteria (LAB) present at different stages of fermentation and also to determine the survival of selected foodborne pathogens in tempoyak. The predominant microorganisms present in tempoyak were LAB (8.88-10.42 log CFU/g). Fructobacillus durionis and Lactobacillus plantarum were the dominant members of LAB. Other LAB species detected for the first time in tempoyak were a fructophilic strain of Lactobacillus fructivorans, Leuconostoc dextranicum, Lactobacillus collinoides and Lactobacillus paracasei. Heterofermentative Leuconostoc mesenteroides and F. durionis were predominant in the initial stage of fermentation, and as fermentation proceeded, F. durionis remained predominant, but towards the end of fermentation, homofermentative Lb. plantarum became the predominant species. Lactic, acetic and propionic acids were present in concentrations ranging from 0.30 to 9.65, 0.51 to 7.14 and 3.90 to 7.31 mg/g, respectively. Genotyping showed a high degree of diversity among F. durionis and Lb. plantarum isolates, suggesting different sources of LAB. All tested Lb. plantarum and F. durionis (except for one isolate) isolates were multidrug resistant. Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were not detected. However, survival study showed that these pathogens could survive up to 8-12 days. The results aiming at improving the quality and safety of tempoyak. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Nutritional Properties and Antinutritional Factors of Corn Paste (Kutukutu Fermented by Different Strains of Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Tchikoua Roger

    2015-01-01

    Full Text Available The aim of this study is to reduce antinutritional factors and to improve the nutritional properties of Kutukutu during fermentation with Lactic Acid Bacteria (LAB. For that, Kutukutu (700 g was prepared in the laboratory and inoculated with pure cultures of LAB (109 CFU/mL. Then, preparation was incubated for 120 h. Every 24 h, Kutukutu were collected, dried at 45°C for 24 h, and analyzed. The results showed that Lactobacillus brevis G25 increased reducing sugars content to 80.7% in Kutukutu after 96 h of fermentation. Lactobacillus fermentum N33 reduced the starch content to 73.2%, while Lactobacillus brevis G11, L. brevis G25, and Lactobacillus cellobiosus M41 rather increased the protein content to 18.9%. The bioavailability of Mg and Fe increased, respectively, to 50.5% and 70.6% in the Kutukutu fermented with L. brevis G25. L. plantarum A6 reduced the tannin content to 98.8% and L. buchneri M11 reduced the phytate content to 95.5%. The principal component analysis (PCA shows that, for a best reduction of antinutrients factors and improvement of protein content and minerals, Kutukutu must be fermented by L. brevis G25 and L. fermentum N33, respectively. These starter cultures could be used to ameliorate nutritional proprieties of Kutukutu during the fermentation.

  3. Purification of bacteriocins using size-exclusion chromatography

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2016-06-01

    Full Text Available The bacteriocin purification involves following main steps. a. Extraction of cell-free-supernatant of bacteria. b. Ammonium sulfate precipitation. c. Dialysis. d. Diafiltration using PVP and e. Size-exclusion chromatography. However, depending on the nature of work, the compound could be further analyzed by reverse-phase HPLC, NMR, mass spectrometry and sequencing.

  4. Nanomaterials and Water Purification: Opportunities and Challenges

    International Nuclear Information System (INIS)

    Savage, Nora; Diallo, Mamadou S.

    2005-01-01

    Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly ameliorated using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes and nanoparticle enhanced filtration among other products and processes resulting from the development of nanotechnology. Innovations in the development of novel technologies to desalinate water are among the most exciting and promising. Additionally, nanotechnology-derived products that reduce the concentrations of toxic compounds to sub-ppb levels can assist in the attainment of water quality standards and health advisories. This article gives an overview of the use of nanomaterials in water purification. We highlight recent advances on the development of novel nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater contaminated by toxic metal ions, radionuclides, organic and inorganic solutes, bacteria and viruses. In addition, we discuss some challenges associated with the development of cost effective and environmentally acceptable functional nanomaterials for water purification

  5. Nanomaterials and Water Purification: Opportunities and Challenges

    Science.gov (United States)

    Savage, Nora; Diallo, Mamadou S.

    2005-10-01

    Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly ameliorated using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes and nanoparticle enhanced filtration among other products and processes resulting from the development of nanotechnology. Innovations in the development of novel technologies to desalinate water are among the most exciting and promising. Additionally, nanotechnology-derived products that reduce the concentrations of toxic compounds to sub-ppb levels can assist in the attainment of water quality standards and health advisories. This article gives an overview of the use of nanomaterials in water purification. We highlight recent advances on the development of novel nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater contaminated by toxic metal ions, radionuclides, organic and inorganic solutes, bacteria and viruses. In addition, we discuss some challenges associated with the development of cost effective and environmentally acceptable functional nanomaterials for water purification.

  6. Proteins of the kidney microvillar membrane. Aspartate aminopeptidase: purification by immunoadsorbent chromatography and properties of the detergent- and proteinase-solubilized forms

    DEFF Research Database (Denmark)

    Danielsen, Erik Michael; Norén, O; Sjöström, H

    1980-01-01

    Aminopeptidase A (aspartate aminopeptidase, EC 3.4.11.7) was purified 2000-fold from pig kidney cortex. The essential step in the purification was chromatography on an immunoadsorbent column prepared from a rabbit antiserum raised against pig intestinal aminopeptidase A. Glutamyl and aspartyl...... revealed 1 g-atom of Ca/143000 g of protein. Two forms of the enzyme were purified: an amphipathic form solubilized from the membrane by Triton X-100 (detergent form) and a hydrophilic form released by incubation with trypsin (proteinase form). The detergent form exhibited charge-shift in crossed...... protein....

  7. Antimicrobial potential of commercial silver nanoparticles and the characterization of their physical properties toward probiotic bacteria isolated from fermented milk products.

    Science.gov (United States)

    Mikiciuk, Jakub; Mikiciuk, Ewa; Wrońska, Anna; Szterk, Arkadiusz

    2016-01-01

    The application of nanotechnology in the agriculture and food sector is relatively recent compared to its usage in drug delivery or pharmaceuticals. Therefore, this paper presents a study of the effect of silver nanoparticles on probiotic bacteria based on the example of Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 and Streptococcus thermophilus ST-Y31 isolated from fermented milk products. Probiotic bacteria are one of the most crucial groups of bacteria for the food industry, because of their claimed health-promoting properties. Studies have shown that the type and concentration of silver nanoparticle solutions have a significant impact on the tested probiotic bacteria which are profitable for the digestive system. In the presence of all tested silver nanoparticles, St. thermophilus ST-Y31 growth was inhibited significantly by the dilution method as opposed to the disk-diffusion method. Both the disk-diffusion and the dilution methods showed no significant differences between L. acidophilus LA-5 and B. animalis subsp. lactis BB-12. The concentrations 2 μg mL(-1) and 0.25 μg mL(-1) had the highest antibacterial activity and statistically significant impacts on the tested probiotic strains. To our knowledge, this is the first report on potential antimicrobial effect of nanosilver against the health-promoting probiotic bacteria L. acidophilus LA-5, B. animalis subsp. lactis BB-12 and St. thermophilus ST-Y31 isolated from fermented milk products.

  8. Identification of Lactic Acid Bacteria in Fruit Pulp Processing Byproducts and Potential Probiotic Properties of Selected Lactobacillus Strains.

    Science.gov (United States)

    Garcia, Estefânia F; Luciano, Winnie A; Xavier, Danilo E; da Costa, Whyara C A; de Sousa Oliveira, Kleber; Franco, Octávio L; de Morais Júnior, Marcos A; Lucena, Brígida T L; Picão, Renata C; Magnani, Marciane; Saarela, Maria; de Souza, Evandro L

    2016-01-01

    This study aimed to identify lactic acid bacteria (LAB) in byproducts of fruit (Malpighia glabra L., Mangifera indica L., Annona muricata L., and Fragaria vesca L.) pulp processing. Fifty strains of LAB were identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequence (16S rRNA) analysis. Species belonging to Lactobacillus genus were the predominant LAB in all fruit pulp processing byproducts. The average congruency between the MALDI-TOF MS and 16S rRNA in LAB species identification reached 86%. Isolates of L. plantarum, L. brevis, L. pentosus, L. lactis and L. mesenteroides were identified with 100% congruency. MALDI-TOF MS and 16S rRNA analysis presented 86 and 100% efficiency of LAB species identification, respectively. Further, five selected Lactobacillus strains (L. brevis 59, L. pentosus 129, L. paracasei 108, L. plantarum 49, and L. fermentum 111) were evaluated for desirable probiotic-related properties and growth behavior on two different cultivation media. The exposure to pH 2.0 sharply decreased the counts of the different Lactobacillus strains after a 1 or 2 h incubation, while varied decreases were noted after 3 h of exposure to pH 3.0. Overall, the exposure to pH 5.0 and to bile salts (0.15, 0.30, and 1.00%) did not decrease the counts of the Lactobacillus strains. All tested Lactobacillus strains presented inhibitory activity against Staphylococcus aureus, Salmonella Typhimurium, Salmonella Enteritidis, Listeria monocytogenes and Escherichia coli, and presented variable susceptibility to different antibiotics. The selected Lactobacillus strains presented satisfactory and reproducible growth behavior. In conclusion, MALDI-TOF MS and 16S rRNA analysis revealed high efficiency and congruency for LAB species identification, and the selected Lactobacillus strains may be candidates for further investigation of novel probiotic strains.

  9. Identification of lactic acid bacteria in fruit pulp processing byproducts and potential probiotic properties of selected Lactobacillus strains

    Directory of Open Access Journals (Sweden)

    Estefânia Garcia

    2016-08-01

    Full Text Available This study aimed to identify lactic acid bacteria (LAB in byproducts of fruit (Malpighia glabra L., Mangifera indica L., Annona muricata L. and Fragaria vesca L. pulp processing. Fifty strains of LAB were identified using matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI-TOF MS and 16S rRNA gene sequence (16S rRNA analysis. Species belonging to Lactobacillus genus were the predominant LAB in all fruit pulp processing byproducts. The average congruency between the MALDI-TOF MS and 16S rRNA in LAB species identification reached 86%. Isolates of L. plantarum, L. brevis, L. pentosus, L. lactis and L. mesenteroides were identified with 100% congruency. MALDI-TOF MS and 16S rRNA analysis presented 86% and 100% efficiency of LAB species identification, respectively. Further, five selected Lactobacillus strains (L. brevis 59, L. pentosus 129, L. paracasei 108, L. plantarum 49 and L. fermentum 111 were evaluated for desirable probiotic-related properties and growth behavior on two different cultivation media. The exposure to pH 2.0 sharply decreased the counts of the different Lactobacillus strains after a 1 or 2 h incubation, while varied decreases were noted after 3 h of exposure to pH 3.0. Overall, the exposure to pH 5.0 and to bile salts (0.15, 0.30 and 1.00% did not decrease the counts of the Lactobacillus strains. All tested Lactobacillus strains presented inhibitory activity against Staphylococcus aureus, Salmonella Typhimurium, Salmonella Enteritidis, Listeria monocytogenes and Escherichia coli, and presented variable susceptibility to different antibiotics. The selected Lactobacillus strains presented satisfactory and reproducible growth behavior. In conclusion, MALDI-TOF MS and 16S rRNA analysis revealed high efficiency and congruency for LAB species identification, and the selected Lactobacillus strains may be candidates for further investigation of novel probiotic strains.

  10. Solid State Air Purification System

    Data.gov (United States)

    National Aeronautics and Space Administration — The solid state air purification project will explore feasibility of a new air purification system based on a liquid membrane, capable of purifying carbon dioxide...

  11. [The effect of bacteria reaction time on corrosion properties of Ni-Cr alloys pretreated with different proteins].

    Science.gov (United States)

    Qi, Han-quan; Zhang, Song-mei; Qian, Chao; Yuan-Li, Zheng

    2015-12-01

    To evaluate the corrosion properties of absorbed protein on the surface of NiCr alloys, and provide experimental base for corrosion resistance of dental casting alloys. NiCr alloy specimens were divided into 3 groups: one group was exposed to the artificial saliva(control group), and the other 2 groups were exposed to the artificial saliva with 1% bovine serum albumin(BSA), or 0.22% lysozyme(LSZ). Group of BSA and group of LSZ were the experimental group. Specimens in 3 groups were cultured in solution of Streptococcus mutans for 12 h, 24 h, 36 h and 48h, and investigated with electrochemical impedance spectroscopy measurement(EIS) and potentiodynamic polarization measurement(POT) to determine the corrosion resistance of the alloys. The data was analyzed with SPSS 17.0 software package. The results indicated that the corrosion resistance of both BSA group and LSZ group were higher than that of the control group (Pcorrosion resistance of BSA group and LSZ group had no significant difference (P>0.05), but was still higher than that of the control group. After 36 h culture time, the control group and the BSA group had no statistical difference in corrosion resistance (P>0.05), while the LSZ group had the poorest corrosion resistance. When the culture time extended to 48 h, the control group had a better corrosion resistance compared with the BAS group and the LSZ group(Pcorrosion properties than LSZ group. The potentiodynamic polarization curve and electrochemical impedance spectroscopy had similar results. The adhesion of BSA and LSZ on the surface of the NiCr alloys in the early time could effectively inhibit the corrosive effect of Streptococcus mutans. The LSZ had better effect than BSA. With the continuing role of bacteria and the consumption of the absorb protein, the corrosion resistance of NiCr alloys toward Streptococcus mutans becomes lower than the alloys without absorb protein, which demonstrated that the adhesion of protein would change the surface

  12. Purification of lipases.

    Science.gov (United States)

    Taipa, M A; Aires-Barros, M R; Cabral, J M

    1992-11-01

    Interest on lipases from different sources (microorganisms, animals and plants) has markedly increased in the last decade due to the potential applications of lipases in industry and in medicine. Microbial and mammalian lipases have been purified to homogeneity, allowing the successful determination of their primary aminoacid sequence and, more recently, of the three-dimensional structure. The X-ray studies of pure lipases will enable the establishment of the structure-function relationships and contribute for a better understanding of the kinetic mechanisms of lipase action on hydrolysis, synthesis and group exchange of esters. This article reviews the separation and purification techniques that were used in the recovery of microbial, mammalian and plant lipases. Several purification procedures are analysed taking into account the sequence of the methods and the number of times each method is used. Novel purification methods based on liquid-liquid extraction, membrane processes and immunopurification are also reviewed.

  13. Microscopic Examination of Distribution and Phenotypic Properties of Phylogenetically Diverse Chloroflexaceae-Related Bacteria in Hot Spring Microbial Mats

    DEFF Research Database (Denmark)

    Nübel, U.; Bateson, Mary M.; Vandieken, V.

    2002-01-01

    -scale distribution. FISH was combined with oxygen microelectrode measurements, microscope spectrometry, and microautoradiography to examine their microenvironment, pigmentation, and carbon source usage. Abundant type C-related, filamentous bacteria were found to flourish within the cyanobacterium-dominated, highly...

  14. Water purification in Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Giammarchi, M. [Infn Milano (Italy); Balata, M.; Ioannucci, L.; Nisi, S. [Laboratori Nazionali del Gran Sasso (Italy); Goretti, A.; Ianni, A. [Princeton University (United States); Miramonti, L. [Dip. di Fisica dell' Università di Milano e Infn (Italy)

    2013-08-08

    Astroparticle Physics and Underground experiments searching for rare nuclear events, need high purity materials to act as detectors or detector shielding. Water has the advantage of being cheap, dense and easily available. Most of all, water can be purified to the goal of obatining a high level of radiopurity. Water Purification can be achieved by means of a combination of processes, including filtration, reverse osmosis, deionization and gas stripping. The Water Purification System for the Borexino experiment, will be described together with its main performances.

  15. Sodium purification in Rapsodie

    International Nuclear Information System (INIS)

    Giraud, B.

    1968-01-01

    This report is one of a series of publications presenting the main results of tests carried out during the start-up of the first french fast neutron reactor: Rapsodie. The article presents the sodium purification techniques used in the reactor cooling circuits both from the constructional point of view and with respect to results obtained during the first years working. (author) [fr

  16. Microscopic examination of distribution and phenotypic properties of phylogenetically diverse Chloroflexaceae-related bacteria in hot spring microbial mats

    DEFF Research Database (Denmark)

    Nübel, Ulrich; Bateson, Mary M; Vandieken, Verona

    2002-01-01

    -scale distribution. FISH was combined with oxygen microelectrode measurements, microscope spectrometry, and microautoradiography to examine their microenvironment, pigmentation, and carbon source usage. Abundant type C-related, filamentous bacteria were found to flourish within the cyanobacterium-dominated, highly...... rRNA genes, an unexpectedly large phylogenetic diversity among these bacteria was detected. Oligonucleotide probes were designed to target 16S rRNAs from organisms affiliated with the genus Chloroflexus or with the type C cluster, a group of previously discovered Chloroflexaceae relatives...... to the upper millimeter of the mat. Both type C organisms and Chloroflexus spp. were observed to assimilate radiolabeled acetate under in situ conditions....

  17. Ash study for biogas purification

    International Nuclear Information System (INIS)

    Juarez V, R. I.

    2016-01-01

    This work evaluates the ashes generated from the wood and coal combustion process of the thermoelectric plant in Petacalco, Guerrero (Mexico) in order to determine its viability as a filter in the biogas purification process. The ash is constituted by particles of morphology and different chemical properties, so it required a characterization of the same by different analytical techniques: as was scanning electron microscopy and X-ray diffraction, in order to observe the microstructure and determine the elemental chemical composition of the particles. Prior to the analysis, a set of sieves was selected to classify as a function of particle size. Four different types of ashes were evaluated: one generated by the wood combustion (wood ash) and three more of the Petacalco thermoelectric generated by the coal combustion (wet fly ash, dry fly ash and dry bottom ash). (Author)

  18. An in vitro evaluation of the antibacterial properties of three mineral trioxide aggregate (MTA) against five oral bacteria.

    Science.gov (United States)

    Kim, Ryan Jin-Young; Kim, Myung-Ook; Lee, Ki-Sun; Lee, Dong-Yul; Shin, Joo-Hee

    2015-10-01

    The purpose of this study was to evaluate the antibacterial ability of three MTA (MTA-Angelus, Endocem MTA, and ProRoot MTA) against five typical oral bacteria (Streptococcus mutans, Enterococcus faecalis, Lactobacillus rhamnosus, Lactobacillus paracasei, and Porphyromonas gingivalis). For disc diffusion test, each test material was placed into agar plates after inoculation of each bacterial strain. The zones of inhibition of bacterial growth were then measured. Antibacterial broth test was performed by adding the test material into the media. Colony-forming units were counted after incubation with bacteria. The data were analyzed using ANOVA and the Tukey's test. Disc diffusion test showed that the antibacterial activity against S. mutans, L. rhamnosus, L. paracasei, and P. gingivalis ranked in decreasing order of MTA-Angelus>ProRoot MTA>Endocem MTA (pMTA. Antibacterial broth test showed that the antibacterial activity against all bacteria was Endocem MTA>MTA-Angelus>ProRoot MTA (pMTA-Angelus and Endocem MTA being most effective, respectively. Both tests revealed that the most resistant bacteria was E. faecalis, which was not susceptible at all, except to Endocem MTA in disc diffusion test. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Population structure of manganese-oxidizing bacteria in stratified soils and properties of manganese oxide aggregates under manganese-complex medium enrichment.

    Directory of Open Access Journals (Sweden)

    Weihong Yang

    Full Text Available Manganese-oxidizing bacteria in the aquatic environment have been comprehensively investigated. However, little information is available about the distribution and biogeochemical significance of these bacteria in terrestrial soil environments. In this study, stratified soils were initially examined to investigate the community structure and diversity of manganese-oxidizing bacteria. Total 344 culturable bacterial isolates from all substrata exhibited Mn(II-oxidizing activities at the range of 1 µM to 240 µM of the equivalent MnO2. The high Mn(II-oxidizing isolates (>50 mM MnO2 were identified as the species of phyla Actinobacteria, Firmicutes and Proteobacteria. Seven novel Mn(II-oxidizing bacterial genera (species, namely, Escherichia, Agromyces, Cellulomonas, Cupriavidus, Microbacterium, Ralstonia, and Variovorax, were revealed via comparative phylogenetic analysis. Moreover, an increase in the diversity of soil bacterial community was observed after the combined enrichment of Mn(II and carbon-rich complex. The phylogenetic classification of the enriched bacteria represented by predominant denaturing gradient gel electrophoresis bands, was apparently similar to culturable Mn(II-oxidizing bacteria. The experiments were further undertaken to investigate the properties of the Mn oxide aggregates formed by the bacterial isolates with high Mn(II-oxidizing activity. Results showed that these bacteria were closely encrusted with their Mn oxides and formed regular microspherical aggregates under prolonged Mn(II and carbon-rich medium enrichment for three weeks. The biotic oxidation of Mn(II to Mn(III/IV by these isolates was confirmed by kinetic examinations. X-ray diffraction assays showed the characteristic peaks of several Mn oxides and rhodochrosite from these aggregates. Leucoberbelin blue tests also verified the Mn(II-oxidizing activity of these aggregates. These results demonstrated that Mn oxides were formed at certain amounts under the

  20. Feasibility Study on Manufacturing Lightweight Aggregates from Water Purification Sludge

    Science.gov (United States)

    Peng, Ching-Fang; Chen, How-Ji

    2018-02-01

    This study mainly discussed the feasibility of manufacturing lightweight aggregates from water purification sludge in Taiwan. They were analysed for the physical and chemical composition before the sintering test for lightweight aggregates in a laboratory. Then the physical and mechanical properties of the synthesized aggregates were assessed. The result showed that the chemical composition of sludge in the water purification plants was within the appropriate range for manufacturing lightweight aggregate as proposed in the literature. The sintering test demonstrated that the particle density of aggregates from the ten types of water purification sludge were mostly less than 1.8 g/cm3. In addition, the dry unit weight, the organic impurity, the ignition loss, and other characteristics of synthesized aggregates met the requirement of CNS standards, while its water absorption and crushing strength also fulfilled the general commercial specifications. Therefore, reclamation of water purification sludge for production of lightweight aggregate is indeed feasible.

  1. Purification and Properties of Extracellular Lipases with Transesterification Activity and 1,3-Regioselectivity fromRhizomucor mieheiandRhizopus oryzae.

    Science.gov (United States)

    Takó, Miklós; KotogÁn, Alexandra; Papp, TamÁs; Kadaikunnan, Shine; Alharbi, Naiyf S; VÁgvölgyi, Csaba

    2017-02-28

    Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p -Nitrophenyl palmitate ( p NPP) hydrolysis was maximal at 40°C and pH 7.0 for the R. miehei lipase, and at 30°C and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to p NPP, but the V max of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM Hg 2+ , Zn 2+ , or Mn 2+ , 10 mM N -bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n -hexane, cyclohexane, n -heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the p NPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p -nitrophenyl ( p NP) esters with C8-C16 acids, exhibiting maximum activity towards p NP-caprylate ( R. miehei ) and pNP-dodecanoate ( Rh. oryzae ). The purified lipases are promising candidates for various biotechnological applications.

  2. Effect of Pseudomonas Sp. Bacteria on Soil Chemical and Biological Properties, Yield and Its Components of Two Rice Cultivars

    Directory of Open Access Journals (Sweden)

    Z. AminDeldar

    2014-04-01

    Full Text Available To evaluate the effect of plant growth promoting bacteria (PGPB on soil physical and chemical indices, yield and its components of two rice cultivars, an experiment was arranged in Rice Researches Institute of Guilan Province during 2009. The experiment design consisted of four randomized complete blocks in a factorial arrangement having 16 treatments in every block. In this research, two factors were evaluated: first, two cultivars (Khazar and Hashemi and second, eight levels of seed inoculation with PGPB (P.fluorescens strain 168, P.fluorescens strain 93, P.fluorescens strain 177, P.fluorescens strain 136, P.fluorescens strain 103, P.fluorescens strain 169, P.fluorescens strain 4 and control (without inoculation. Investigated characteristics consisted of: soil minerals, no.microorganisms in soil, grain yield, number of seed per panicle, number of seed per plant, 1000-seed weight, biological and economic yield. In this experiment, effect of cultivar and bacteria were significant in the most of studied characteristics, but effect of cultivar*bacteria (except yield components wasn’t significant. The results of experiment showed that inoculation with bacterial strains had a stimulating effect on growth and development of rice cultivars. In this experiment, Khazar had positive effect on the most of studied characteristics in compared with Hashemi. Between bacterial different strains, seed inoculation with 168, 177 and 93 strains in compared with other strains increased evaluated characteristics significantly. Seed inoculation with PGPB improved studied characteristics and microorganisms in soil, too.

  3. Antimicrobial properties of cultivable bacteria associated with seaweeds in the Gulf of Mannar on the southeast coast of India.

    Science.gov (United States)

    Thilakan, B; Chakraborty, K; Chakraborty, R D

    2016-08-01

    In this study, 234 bacterial strains were isolated from 7 seaweed species in the Gulf of Mannar on the southeast coast of India. The strains having consistent antimicrobial activity were chosen for further studies, and this constituted about 9.8% of the active strains isolated. Phylogenetic analysis using 16S rDNA sequencing with the help of classical biochemical identification indicated the existence of 2 major phyla, Firmicutes and Proteobacteria. Antimicrobial activity analysis combined with the results of amplifying genes encoding for polyketide synthetase and nonribosomal peptide synthetase showed that seaweed-associated bacteria had broad-spectrum antimicrobial activity. These epibionts might be beneficial to seaweeds by limiting or preventing the development of competing or fouling bacteria. Phylogenetic analysis of ketosynthase (KS) regions with respect to the diverse range of KS domains showed that the KS domains from the candidate isolates were of Type I. The bacterial cultures retained their antimicrobial activities after plasmid curing, which further suggested that the antimicrobial activity of these isolates was not encoded by plasmid, and the genes encoding the antimicrobial product might be present within the genome. Seaweed-associated bacteria with potential antimicrobial activity suggested that the seaweed species are an ideal ecological niche harboring specific bacterial diversity representing a largely underexplored source of antimicrobial secondary metabolites.

  4. Nanotechnology for water treatment and purification

    CERN Document Server

    Apblett, Allen

    2014-01-01

    This book describes the latest progress in the application of nanotechnology for water treatment and purification. Leaders in the field present both the fundamental science and a comprehensive overview of the diverse range of tools and technologies that have been developed in this critical area. Expert chapters present the unique physicochemical and surface properties of nanoparticles and the advantages that these provide for engineering applications that ensure a supply of safe drinking water for our growing population. Application areas include generating fresh water from seawater, preventing contamination of the environment, and creating effective and efficient methods for remediation of polluted waters. The chapter authors are leading world-wide experts in the field with either academic or industrial experience, ensuring that this comprehensive volume presents the state-of-the-art in the integration of nanotechnology with water treatment and purification. Covers both wastewater and drinking water treatmen...

  5. Using of Mineral Recourses for Water Purification

    International Nuclear Information System (INIS)

    Tumanova, I.V.; Nazarenko, O.B.; Anna, Yu.

    2009-01-01

    Pollution of surface waters results in necessity of underground waters using for drinking. Underground waters are characterized by the high quantity of heavy metals salts. This led to development of methods reducing the concentration of the metal salts in water. Wide spread occurrence, cheapness and high sorption properties of nature minerals allow to consider them as perspective sorbents for different impurities extraction, including dissoluble compounds of heavy metals. Reachable purification efficiency with mineral resources use for the moment satisfies sanitary indexes and standards presenting to portable water in Russia. In given material there are presented the results of research of artificial sorbent and certain minerals sorption characteristics, which are typical for West Siberia. For purification quality improvement from Fe and Mn ions there are suggested to use the method of boiling bed.

  6. BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT

    Science.gov (United States)

    2017-07-07

    TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY ( BaCTeRIA ) SUMMARY REPORT by Tobyn A. Branck Courtney M. Cowell Jennifer M. Rego and...October 2011 – September 2015 4. TITLE AND SUBTITLE BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY ( BaCTeRIA ) SUMMARY REPORT...ANTHRAX PURIFICATION BACILLUS ANTHRACIS ENVIRONMENTAL ISOLATES BACTERIA BACTERIOCINS TARGETED ACTIVITY

  7. Taurolidine antiadhesive properties on interaction with E. coli; its transformation in biological environment and interaction with bacteria cell wall.

    Science.gov (United States)

    Caruso, Francesco; Darnowski, James W; Opazo, Cristian; Goldberg, Alexander; Kishore, Nina; Agoston, Elin S; Rossi, Miriam

    2010-01-28

    The taurine amino-acid derivative, taurolidine, bis-(1,1-dioxoperhydro-1,2,4-thiabiazinyl-4)methane, shows broad antibacterial action against gram-positive and gram-negative bacteria, mycobacteria and some clinically relevant fungi. It inhibits, in vitro, the adherence of Escherichia coli and Staphylococcus aureus to human epithelial and fibroblast cells. Taurolidine is unstable in aqueous solution and breaks down into derivatives which are thought to be responsible for the biological activity. To understand the taurolidine antibacterial mechanism of action, we provide the experimental single crystal X-ray diffraction results together with theoretical methods to characterize the hydrolysis/decomposition reactions of taurolidine. The crystal structure features two independent molecules linked through intermolecular H-bonds with one of them somewhat positively charged. Taurolidine in a biological environment exists in equilibrium with taurultam derivatives and this is described theoretically as a 2-step process without an energy barrier: formation of cationic taurolidine followed by a nucleophilic attack of O(hydroxyl) on the exocyclic C(methylene). A concerted mechanism describes the further hydrolysis of the taurolidine derivative methylol-taurultam. The interaction of methylol-taurultam with the diaminopimelic NH(2) group in the E. coli bacteria cell wall (peptidoglycan) has a negative DeltaG value (-38.2 kcal/mol) but a high energy barrier (45.8 kcal/mol) suggesting no reactivity. On the contrary, taurolidine docking into E. coli fimbriae protein, responsible for bacteria adhesion to the bladder epithelium, shows it has higher affinity than mannose (the natural substrate), whereas methylol-taurultam and taurultam are less tightly bound. Since taurolidine is readily available because it is administered in high doses after peritonitis surgery, it may successfully compete with mannose explaining its effectiveness against bacterial infections at laparoscopic lesions.

  8. Taurolidine antiadhesive properties on interaction with E. coli; its transformation in biological environment and interaction with bacteria cell wall.

    Directory of Open Access Journals (Sweden)

    Francesco Caruso

    Full Text Available The taurine amino-acid derivative, taurolidine, bis-(1,1-dioxoperhydro-1,2,4-thiabiazinyl-4methane, shows broad antibacterial action against gram-positive and gram-negative bacteria, mycobacteria and some clinically relevant fungi. It inhibits, in vitro, the adherence of Escherichia coli and Staphylococcus aureus to human epithelial and fibroblast cells. Taurolidine is unstable in aqueous solution and breaks down into derivatives which are thought to be responsible for the biological activity. To understand the taurolidine antibacterial mechanism of action, we provide the experimental single crystal X-ray diffraction results together with theoretical methods to characterize the hydrolysis/decomposition reactions of taurolidine. The crystal structure features two independent molecules linked through intermolecular H-bonds with one of them somewhat positively charged. Taurolidine in a biological environment exists in equilibrium with taurultam derivatives and this is described theoretically as a 2-step process without an energy barrier: formation of cationic taurolidine followed by a nucleophilic attack of O(hydroxyl on the exocyclic C(methylene. A concerted mechanism describes the further hydrolysis of the taurolidine derivative methylol-taurultam. The interaction of methylol-taurultam with the diaminopimelic NH(2 group in the E. coli bacteria cell wall (peptidoglycan has a negative DeltaG value (-38.2 kcal/mol but a high energy barrier (45.8 kcal/mol suggesting no reactivity. On the contrary, taurolidine docking into E. coli fimbriae protein, responsible for bacteria adhesion to the bladder epithelium, shows it has higher affinity than mannose (the natural substrate, whereas methylol-taurultam and taurultam are less tightly bound. Since taurolidine is readily available because it is administered in high doses after peritonitis surgery, it may successfully compete with mannose explaining its effectiveness against bacterial infections at

  9. Identification of Coccoidal Bacteria in Traditional Fermented Milk Products from Mongolia, and the Fermentation Properties of the Predominant Species, Streptococcus thermophilus

    Science.gov (United States)

    2015-01-01

    The objective of this study was to identify the coccoidal bacteria present in 188 samples of fermented yaks’, mares’ and cows’ milk products collected from 12 different regions in Mongolia. Furthermore, we evaluated the fermentation properties of ten selected isolates of the predominant species, Streptococcus (S.) thermophiles, during the process of milk fermentation and subsequent storage of the resulting yoghurt at 4℃. Overall, 159 isolates were obtained from 188 samples using M17 agar. These isolates were presumed to be lactic acid bacteria based on their gram-positive and catalase-negative properties, and were identified to species level using 16S rRNA gene sequence analysis. These coccoid isolates were distributed in four genera and six species: Enterococcus (E.) durans, Enterococcus (E.) faecalis, Lactococcus (Lac.) subsp. lactis, Leuconostoc (Leuc.) lactis, Leuconostoc (Leuc.) mesenteroides. subsp. mesenteroides and S. thermophilus. Among these S. thermophilus was the most common species in most samples. From evaluation of the fermentation characteristics (viable counts, pH, titratable acidity [TA]) of ten selected S. thermophilus isolates we could identify four isolates (IMAU 20246, IMAU20764, IMAU20729 and IMAU20738) that were fast acid producers. IMAU20246 produced the highest concentrations of lactic acid and formic acid. These isolates have potential as starter cultures for yoghurt production. PMID:26761898

  10. The purification of hypertensin II.

    Science.gov (United States)

    SKEGGS, L T; KAHN, J R; SHUMWAY, N P

    1956-03-01

    The enzymatic conversion of hypertensin I to hypertensin II is described together with the subsequent purification of the product by means of counter-current distribution. Improved methods are also presented for the preparation of renin and its substrate, as well as in methods for the reaction of these materials and the purification of the resulting hypertensin I.

  11. Protein production and purification.

    Science.gov (United States)

    Gräslund, Susanne; Nordlund, Pär; Weigelt, Johan; Hallberg, B Martin; Bray, James; Gileadi, Opher; Knapp, Stefan; Oppermann, Udo; Arrowsmith, Cheryl; Hui, Raymond; Ming, Jinrong; dhe-Paganon, Sirano; Park, Hee-won; Savchenko, Alexei; Yee, Adelinda; Edwards, Aled; Vincentelli, Renaud; Cambillau, Christian; Kim, Rosalind; Kim, Sung-Hou; Rao, Zihe; Shi, Yunyu; Terwilliger, Thomas C; Kim, Chang-Yub; Hung, Li-Wei; Waldo, Geoffrey S; Peleg, Yoav; Albeck, Shira; Unger, Tamar; Dym, Orly; Prilusky, Jaime; Sussman, Joel L; Stevens, Ray C; Lesley, Scott A; Wilson, Ian A; Joachimiak, Andrzej; Collart, Frank; Dementieva, Irina; Donnelly, Mark I; Eschenfeldt, William H; Kim, Youngchang; Stols, Lucy; Wu, Ruying; Zhou, Min; Burley, Stephen K; Emtage, J Spencer; Sauder, J Michael; Thompson, Devon; Bain, Kevin; Luz, John; Gheyi, Tarun; Zhang, Fred; Atwell, Shane; Almo, Steven C; Bonanno, Jeffrey B; Fiser, Andras; Swaminathan, Sivasubramanian; Studier, F William; Chance, Mark R; Sali, Andrej; Acton, Thomas B; Xiao, Rong; Zhao, Li; Ma, Li Chung; Hunt, John F; Tong, Liang; Cunningham, Kellie; Inouye, Masayori; Anderson, Stephen; Janjua, Heleema; Shastry, Ritu; Ho, Chi Kent; Wang, Dongyan; Wang, Huang; Jiang, Mei; Montelione, Gaetano T; Stuart, David I; Owens, Raymond J; Daenke, Susan; Schütz, Anja; Heinemann, Udo; Yokoyama, Shigeyuki; Büssow, Konrad; Gunsalus, Kristin C

    2008-02-01

    In selecting a method to produce a recombinant protein, a researcher is faced with a bewildering array of choices as to where to start. To facilitate decision-making, we describe a consensus 'what to try first' strategy based on our collective analysis of the expression and purification of over 10,000 different proteins. This review presents methods that could be applied at the outset of any project, a prioritized list of alternate strategies and a list of pitfalls that trip many new investigators.

  12. Gas purification project

    International Nuclear Information System (INIS)

    Broothaerts, J.; Claes, J.; Collard, G.; Goossens, W.; Harnie, R.; Heylen, P.; Vaesen, J.; Beukelaer, R. de; Dubois, G.; Glibert, R.; Mestrez, J.; Zahlen, A.

    1975-06-01

    Conceptual and experimental studies on LMFBR reprocessing and reactor off-gas purification systems are summarized. Iodine sorption on zeolites, low-temperature adsorption of noble gases on charcoal and catalytic oxidation of hydrogen, simulating tritium, are being studied in laboratory set-ups. A pilot loop with 25 m 3 h -1 throughput has been constructed. Results are quoted from the first phase of the iodine removal programme by scrubbing systems. Further extension of the test loop, comprising off-gases conditioning to removal of krypton in a cryodistillation unit, has been prepared. Delay-bed studies on 133 Xe extraction from LWR off-gases are reported. (author)

  13. Air/Water Purification

    Science.gov (United States)

    1992-01-01

    After 18 years of research into air/water pollution at Stennis Space Center, Dr. B. C. Wolverton formed his own company, Wolverton Environmental Services, Inc., to provide technology and consultation in air and water treatment. Common houseplants are used to absorb potentially harmful materials from bathrooms and kitchens. The plants are fertilized, air is purified, and wastewater is converted to clean water. More than 100 U.S. communities have adopted Wolverton's earlier water hyacinth and artificial marsh applications. Catfish farmers are currently evaluating the artificial marsh technology as a purification system.

  14. Water Purification Product

    Science.gov (United States)

    2004-01-01

    Ecomaster, an affiliate of BioServe Space Technologies, this PentaPure technology has been used to purify water for our nation's Space Shuttle missions since 1981. WTC-Ecomaster of Mirneapolis, Minnesota manufactures water purification systems under the brand name PentaPure (TM). BioServe researcher Dr. George Marchin, of Kansas State University, first demonstrated the superiority of this technology and licensed it to WTC. Marchin continues to perform microgravity research in the development of new technologies for the benefit of life on Earth.

  15. A panorama of bacterial inulinases: Production, purification, characterization and industrial applications.

    Science.gov (United States)

    Singh, Ram Sarup; Chauhan, Kanika; Kennedy, John F

    2017-03-01

    Inulinases are important hydrolysing enzymes which specifically act on β-2, 1 linkages of inulin to produce fructose or fructooligosaccharides. Fungi, yeasts and bacteria are the potent microbial sources of inulinases. The data on bacterial inulinases is scarce as compared to other microbial sources. Inulinases yield from bacteria is very less as compared to fungal and yeast sources of inulinases. Submerged fermentation (SmF) is the method of choice for the production of inulinases from bacterial sources. Moreover, inulin is a potent substrate for the production of inulinases in SmF. Many bacterial inulinases have been reported to display magnificent environment abiding features and variability in their biophysical and biochemical properties. These properties have attracted intention of many researchers towards exploring adverse ecological niches for more distinctive inulinase producing bacterial strains. Inulinases are substantially important in current biotechnological era due to their numerous industrial applications. High fructose syrup and fructooligosaccharides are two major industrial applications of inulinases. Additionally, there are many reports on the production of various metabolites like citric acid, lactic acid, ethanol, biofuels, butanediol etc. using mixed cultures of inulinase producing organisms with other microorganisms. The present review mainly envisages inulinase producing bacterial sources, inulinase production, purification, characterization and their applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Purification and characterization of riproximin from Ximenia americana fruit kernels.

    Science.gov (United States)

    Bayer, Helene; Ey, Noreen; Wattenberg, Andreas; Voss, Cristina; Berger, Martin R

    2012-03-01

    Highly pure riproximin was isolated from the fruit kernels of Ximenia americana, a defined, seasonally available and potentially unlimited herbal source. The newly established purification procedure included an initial aqueous extraction, removal of lipids with chloroform and subsequent chromatographic purification steps on a strong anion exchange resin and lactosyl-Sepharose. Consistent purity and stable biological properties were shown over several purification batches. The purified, kernel-derived riproximin was characterized in comparison to the African plant material riproximin and revealed highly similar biochemical and biological properties but differences in the electrophoresis pattern and mass spectrometry peptide profile. Our results suggest that although the purified fruit kernel riproximin consists of a mixture of closely related isoforms, it provides a reliable basis for further research and development of this type II ribosome inactivating protein (RIP). Copyright © 2011 Elsevier Inc. All rights reserved.

  17. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  18. Effect of charcoal on water purification

    OpenAIRE

    Suzuki, Hirotaka; Kawahigashi, Tatsuo

    2014-01-01

    [Abstract] A natural basin system purifies water through self-purification, but the water pollution load of a river might exceed its self-purification capacity. Charcoal, which is used for other uses aside from heating, such as air purification, was evaluated experimentally for water quality purification. The experiment described herein is based on simple water quality measurements. Some experimentally obtained results are discussed.

  19. In-situ determination of the mechanical properties of gliding or non-motile bacteria by atomic force microscopy under physiological conditions without immobilization.

    Directory of Open Access Journals (Sweden)

    Samia Dhahri

    Full Text Available We present a study about AFM imaging of living, moving or self-immobilized bacteria in their genuine physiological liquid medium. No external immobilization protocol, neither chemical nor mechanical, was needed. For the first time, the native gliding movements of Gram-negative Nostoc cyanobacteria upon the surface, at speeds up to 900 µm/h, were studied by AFM. This was possible thanks to an improved combination of a gentle sample preparation process and an AFM procedure based on fast and complete force-distance curves made at every pixel, drastically reducing lateral forces. No limitation in spatial resolution or imaging rate was detected. Gram-positive and non-motile Rhodococcus wratislaviensis bacteria were studied as well. From the approach curves, Young modulus and turgor pressure were measured for both strains at different gliding speeds and are ranging from 20±3 to 105±5 MPa and 40±5 to 310±30 kPa depending on the bacterium and the gliding speed. For Nostoc, spatially limited zones with higher values of stiffness were observed. The related spatial period is much higher than the mean length of Nostoc nodules. This was explained by an inhomogeneous mechanical activation of nodules in the cyanobacterium. We also observed the presence of a soft extra cellular matrix (ECM around the Nostoc bacterium. Both strains left a track of polymeric slime with variable thicknesses. For Rhodococcus, it is equal to few hundreds of nanometers, likely to promote its adhesion to the sample. While gliding, the Nostoc secretes a slime layer the thickness of which is in the nanometer range and increases with the gliding speed. This result reinforces the hypothesis of a propulsion mechanism based, for Nostoc cyanobacteria, on ejection of slime. These results open a large window on new studies of both dynamical phenomena of practical and fundamental interests such as the formation of biofilms and dynamic properties of bacteria in real physiological conditions.

  20. Electroresponsive Supramolecular Graphene Oxide Hydrogels for Active Bacteria Adsorption and Removal.

    Science.gov (United States)

    Xue, Bin; Qin, Meng; Wu, Junhua; Luo, Dongjun; Jiang, Qing; Li, Ying; Cao, Yi; Wang, Wei

    2016-06-22

    Bacteria contamination in drinking water and medical products can cause severe health problems. However, currently available sterilization methods, mainly based on the size-exclusion mechanism, are typically slow and require the entire contaminated water to pass through the filter. Here, we present an electroresponsive hydrogel based approach for bacteria adsorption and removal. We successfully engineered a series of graphene oxide hydrogels using redox-active ruthenium complexes as noncovalent cross-linkers. The resulting hydrogels can reversibly switch their physical properties in response to the applied electric field along with the changes of oxidation states of the ruthenium ions. The hydrogels display strong bacteria adsorbing capability. A hydrogel of 1 cm(3) can adsorb a maximum of 1 × 10(8) E. coli. The adsorbed bacteria in the hydrogels can then be inactivated by a high voltage electric pulse and removed from the hydrogels subsequently. Owing to the high bacteria removal rate, reusability, and low production cost, these hydrogels represent promising candidates for the emergent sterilization of medical products or large-scale purification of drinking water.

  1. Identification and functional properties of dominant lactic acid bacteria isolated from Kahudi, a traditional rapeseed fermented food product of Assam, India

    Directory of Open Access Journals (Sweden)

    Gunajit Goswami

    2017-09-01

    Full Text Available Kahudi or Pani tenga is a very unique fermented mustard product of Assam that is prepared by mixing coarsely ground mustard with extracts of acidic Garcinia pedunculata (Thekera or tamarind. Kahudi is produced through a spontaneous and uncontrolled solid state fermentation and very little scientific effort has been directed to understand its microflora and their functional properties. In this paper, we report the microbial flora and their dynamics during Kahudi fermentation with special emphasis on lactic acid bacteria (LAB. LAB were found to be dominant (8 log CFU/g over other microbial flora (4 log CFU/g during the fermentation process leading to Kahudi formation. The microbial load in Kahudi did not include any mycelial molds or pathogenic enteric bacteria. Combination of phenotypic parameters, biochemical tests, and 16S rDNA gene sequencing revealed the dominant group of LAB as Enterococcus durans, Lactobacillus plantarum, Lactobacillus fermentum, and Lactobacillus casei. The sugar fermentation and enzyme profile analysis revealed the ability of the microbial consortia to metabolize an array of indigestible sugars including D-mannose, mannitol, sorbitol, methyl-α-D-mannopyranoside, methyl-α-D-glucopyranoside, N-acetylglucosamine, amygdalin, and arbutin. Although the isolates showed good acid phosphatase activity they had weak extracellular phytase activity. This is the first report on the microbial dynamics and involvement of LAB during Kahudi fermentation.

  2. In vitro study of beneficial properties and safety of lactic acid bacteria isolated from Portuguese fermented meat products.

    Science.gov (United States)

    Todorov, S D; Franco, B D G M; Wiid, I J

    2014-09-01

    Many lactic acid bacteria produce bacteriocins with a rather broad spectrum of inhibition, which could offer potential applications in food preservation. Bacteriocin production by starter cultures may bring advantage to these strains in competitive interactions with pathogenic bacteria from the food matrix. The objective of this study was to determine the safety of beneficial strains (Lactobacillus plantarum ST202Ch and ST216Ch, Enterococcus faecium ST211Ch, and Lactobacillus sakei ST22Ch, ST153Ch and ST154Ch) previously isolated from fermented meat products and characterised as bacteriocin producers. Auto-aggregation was strain-specific, and values of 28.97, 27.86 and 28.56% were recorded for L. sakei ST22Ch, ST153Ch and ST154Ch, respectively, 16.95 and 14.58% for L. plantarum ST202Ch and ST216Ch, respectively, and 12.77% for E. faecium ST211Ch. Various degrees of co-aggregation between 28.85 and 44.76% for Listeria monocytogenes 211 and 409, and between 23.60 to 34.96% for E. faecium ATCC 19443 were observed. According to the results of the diffusion method, the studied strains demonstrated susceptibility to penicillin G, ampicillin, amoxicillin, amoxicillin/clavulonic acid, imipenem, linezolid, and tetracycline. In addition, the susceptibility of the six strains to various non-antibiotic commercial drugs was examined. Production of β-galactosidase by L. sakei ST22Ch, ST153Ch and ST154Ch, L. plantarum ST202Ch and ST216Ch, and E. faecium ST211Ch was confirmed by employing sterile filter paper discs impregnated with o-nitrophenyl-β-D-galactopyranose. A statistically significant (P<0.001) inhibition of Mycobacterium tuberculosis growth by bacteriocins produced by L. plantarum ST202Ch (38.3%) and ST216Ch (48.6%), L. sakei ST153Ch (16.2%) and ST154Ch (16.1%), and E. faecium ST211Ch (21.7%) was observed. As determined by the polymerase chain reaction, the tested strains showed a low virulence gene profile.

  3. Magnetic Purification of Antibodies

    Science.gov (United States)

    Dhadge, Vijaykumar Laxman

    This work aimed at the development of magnetic nanoparticles for antibody purification and at the evaluation of their performance in Magnetic fishing and in a newly developed hybrid technology Magnetic Aqueous Two Phase Systems. Magnetic materials were produced by coprecipitation and solvothermal approaches. Natural polymers such as dextran, extracellular polysaccharide and gum Arabic were employed for coating of iron oxide magnetic supports. Polymer coated magnetic supports were then modified with synthetic antibody specific ligands,namely boronic acid, a triazine ligand (named 22/8) and an Ugi ligand (named A2C7I1). To optimize the efficacy of magnetic nanoparticles for antibody magnetic fishing, various solutions of pure and crude antibody solutions along with BSA as a non-specific binding protein were tested. The selectivity of magnetic nanoparticle for antibody, IgG, was found effective with boronic acid and ligand 22/8. Magnetic supports were then studied for their performance in high gradient magnetic separator for effective separation capability as well as higher volume handling capability. The magnetic materials were also supplemented to aqueous two phase systems, devising a new purification technology. For this purpose, magnetic particles modified with boronic acid were more effective. This alternative strategy reduced the time of operation,maximized separation capability (yield and purity), while reducing the amount of salt required. Boronic acid coated magnetic particles bound 170 +/- 10 mg hIgG/g MP and eluted 160 +/- 5 mg hIgG/g MP, while binding only 15 +/- 5 mg BSA/g MP. The affinity constant for the interaction between hIgG and APBA_MP was estimated as 4.9 x 105 M-1 (Ka) with a theoretical maximum capacity of 492 mg hIgG adsorbed/g MP (Qmax). APBA_MPs were also tested for antibody purification directly from CHO cell supernatants. The particles were able to bind 98% of IgG loaded and to recover 95% of pure IgG (purity greater than 98%) at extremely

  4. Purification and properties of a 3 alpha-hydroxysteroid dehydrogenase of rat liver cytosol and its inhibition by anti-inflammatory drugs.

    OpenAIRE

    Penning, T M; Mukharji, I; Barrows, S; Talalay, P

    1984-01-01

    An NAD(P)-dependent 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) was purified to homogeneity from rat liver cytosol, where it is responsible for most if not all of the capacity for the oxidation of androsterone, 1-acenaphthenol and benzenedihydrodiol (trans-1,2-dihydroxycyclohexa-3,5-diene). The dehydrogenase has many properties (substrate specificity, pI, Mr, amino acid composition) in common with the dihydrodiol dehydrogenase (EC 1.3.1.20) purified from the same source [Vogel, Bentley...

  5. Relationship between the adhesive properties of bacteria and their transport and colonization in the subsurface environment. Final report for period September 15, 1996 - September 30, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Madilyn Fletcher

    2000-04-06

    This research has focused on the attachment of bacteria to solid surfaces and the significance of their adhesion properties in their transport through porous media. Our work has focused on strains of Pseudomonas and a related species Burkholderia cepacia. Most of our experimental strains were isolated from subsurface environments at USDOE experimental field sites. The first portion of this project was conducted at the University of Maryland during 1994-1996, during which two graduates and one graduate student were supported by the award. The project was then continued under contract number DE-FG02-96ER62302 at the University of South Carolina, where one postdoctoral associate has been supported by the award.

  6. Effects of single amino acid substitution on the biophysical properties and biological activities of an amphipathic α-helical antibacterial peptide against Gram-negative bacteria.

    Science.gov (United States)

    Tan, Juanjuan; Huang, Jinfeng; Huang, Yibing; Chen, Yuxin

    2014-07-24

    An antimicrobial peptide, known as V13K, was utilized as the framework to study the effects of charge, hydrophobicity and helicity on the biophysical properties and biological activities of α-helical peptides. Six amino acids (Lys, Glu, Gly, Ser, Ala, and Leu) were individually used to substitute the original hydrophobic valine at the selected sixteenth location on the non-polar face of V13K. The results showed that the single amino acid substitutions changed the hydrophobicity of peptide analogs as monitored by RP-HPLC, but did not cause significant changes on peptide secondary structures both in a benign buffer and in a hydrophobic environment. The biological activities of the analogs exhibited a hydrophobicity-dependent behavior. The mechanism of peptide interaction with the outer membrane and cytoplasmic membrane of Gram-negative bacteria was investigated. We demonstrated that this single amino acid substitution method has valuable potential for the rational design of antimicrobial peptides with enhanced activities.

  7. Drying of micro-encapsulated lactic acid bacteria — Effects of trehalose and immobilization on cell survival and release properties

    Science.gov (United States)

    Li, Xiaoyan; Chen, Xiguang

    2009-03-01

    Lactic acid bacteria (LAB) were encapsulated with alginate, gelatin and trehalose additives by the extrusion method and dried at 4 °C. The microcapsules were generally spherical and had a wrinkled surface with a size of 1.7 mm ± 0.2 mm. Trehalose as a carbohydrate source in the culture medium could reduce acid production and performed no function in the positive proliferation of LAB. Using trehalose as a carbohydrate source and protective medium simultaneously had a benefit in the protection of LAB cells during the storage at 4 °C. The density of live LAB cells could be 107 CFU g-1 after 8 weeks of storage. Cells of LAB could be continuously released from the capsules from the acidic (pH 1.2) to neutral conditions (pH 6.8). The release amounts and proliferation speeds of LAB cells in neutral medium were much larger and faster than those in acidic conditions. Additionally, immobilization of LAB could improve the survival of cells when they were exposed to acidic medium (pH 1.2) with a survival rate of 76 %.

  8. PRIMARY CHARACTERIZATION OF SPONGE ASSOCIATED BACTERIA OF MARINE SPONGES- HALICHONDRIA GLABRATA, CLIONA LOBATA, SPIRASTRELLA PACHYSPIRA AND THEIR ANTIMICROBIAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Maushmi Kumar

    2014-10-01

    Full Text Available Marine sponge associated bacterias have been recognized as an important and untapped resource for novel bioactive compounds. In the present study four strains of microorganisms were isolated from three different varieties of marine sponge viz. Halichondria glabrata, Cliona lobata and Spirastrella pachyspira. They showed broad spectrum antimicrobial activity against both Gram positive and Gram negative indicator organisms. From the biochemical tests and cetrimide agar test, it was concluded that the Strain B isolated from Cliona lobata is a Pseudomonas species. Strain A (gram negative culture product isolated from Halichondria glabrata showed the antibiotic activity against Gram positive (B. subtillis and Gram negative (S. typhi, P. vulgaris, E.coli organisms. The minimum inhibitory concentration for showing antibacterial activity on all the standard strain was found to be 40 µL of culture broth supernatant. This strain was further identified by ABIS software based on biochemical tests and confirmation of the strain was done after 16S r RNA gene sequencing. The strain showed close similarity with E. coli and Enterobacteria strains and most of the uncultured bacterium from different hosts, which confirmed its nature of being it a symbiont from sponge Halichondria glabrata with antimicrobial activity.

  9. Effect of antioxidants on thiobarbituric acid reactive substances, psychrotrophic bacteria and functional properties of mechanically deboned chicken meat irradiated with Cobalto-60 and electron beam sources

    International Nuclear Information System (INIS)

    Brito, Poliana de Paula; Azevedo, Heliana de; Roque, Claudio Vitor; Pomarico Neto, Walter

    2013-01-01

    Samples of MDCM with skin were divided into three groups: control (without antioxidants), Antioxidant 1 (Sodium Polyphosphate and Sodium Ascorbate and Antioxidant 2 (Rosemary Extract and α-Tocopherol. The three batches of samples were divided into nine groups: no antioxidant and non-irradiated (C), with antioxidant A1 and non-irradiated (A1), with antioxidant A2 and non-irradiated (A2) without antioxidant and irradiated in Cobalt-60 source (Co), with antioxidant A1 irradiated in Cobalt 60 source (A1Co) with antioxidant A2 irradiated in Cobalt-60 source (A2Co) with antioxidant A1 irradiated in Electron beam (A1Eb) and with antioxidant A2 irradiated in Electron beam (A2Eb). The samples was conditioned in a transparent, low density frozen overnight at a temperature of -18 ± 1 deg C in a chamber, and irradiated in this state with a dose of 3.0 kGy, used two sources of radiation: Cobalt-60 (3.1 kGy/h) and electron beam (7.86 kGy/s). After this process, the samples were evaluated during the refrigeration period (2 ± 1 deg C) for 11 days for the following analysis: total psychrotrophic bacteria count and thiobarbituric acid reactive substances (TBARS) and the analysis of functional properties were performed after the irradiation process. The use of the combination of rosemary antioxidant and α-tocopherol were able to significantly decrease TBARS values caused by the irradiation of samples in MDCM cobalt-60 sources and electron beam, and show a synergetic effect to processing with ionizing radiation to reduce of psychrotrophic bacteria count. The use of irradiation processing of MDCM did not negatively affect the functional properties studied. (author)

  10. Acrylic purification and coatings

    International Nuclear Information System (INIS)

    Kuzniak, Marcin

    2011-01-01

    Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).

  11. Extraction and purification of formonometin from Trifolium pratense L ...

    African Journals Online (AJOL)

    Extraction and purification of formonometin from Trifolium pratense L: Physicochemical properties of its complex with lecithin. ... that there was no significant difference (p < 0.05) between the peak intensity of the physical mixture and the complex, while FT-IR analysis indicated interaction between formononetin and lecithin.

  12. Propriedade antibacteriana de óleos essenciais de especiarias sobre bactérias contaminantes de alimentos Antibacterial property of spice essential oils on food contaminating bacteria

    Directory of Open Access Journals (Sweden)

    Vinicius Nogueira Trajano

    2009-09-01

    Full Text Available As especiarias são conhecidas por exercerem uma estabilidade frente à ação de microrganismos, estando inseridas no grupo dos alimentos estáveis. Esta propriedade conservante das especiarias está relacionada com a presença de compostos antibacterianos na sua composição. Tais compostos podem ser usados no combate a bactérias deteriorantes de alimentos, por esse motivo, este trabalho visa à investigação da propriedade antimicrobiana dos óleos essenciais de Cinnamomum zeylanicum Blume, Coriandrum sativum L., Cuminum cyminum L., Mentha. piperita L., Ocimum basilicum L., Origanum majorana L., Pimpinella anisum L., Piper nigrum L., Rosmarinus officinalis L. e Zingiber officinalis Rosc. frente a bactérias contaminantes de alimentos. Para esse estudo, foram selecionadas 10 cepas bacterianas deteriorantes de alimentos. Para a realização dos ensaios antibacterianos, foi utilizado o método de difusão em meio sólido. Os resultados mostram que os óleos essenciais das folhas do E. caryophyllata e da C. zeylanicum mostraram uma eficiência na inibição de todas as cepas bacterianas ensaiadas. Os outros óleos produziram atividade antibacteriana, porém com menor espectro de ação. A pesquisa de tais produtos mostra-se bastante promissora, sendo essa uma boa alternativa para a substituição de aditivos químicos em alimentos.Spices are known for their stability against microbial action; that being so, they are included in the group of stable foods. This preservative property of spices is related to the presence of antibacterial compounds in their composition. Such compounds could be used to control the food contaminating bacteria. This study aimed to assess the antimicrobial property of the essential oils from Cinnamomum zeylanicum Blume, Coriandrum sativum L., Cuminum cyminum L., Mentha. piperita L., Ocimum basilicum L., Origanum majorana L., Pimpinella anisum L., Piper nigrum L., Rosmarinus officinalis L., and Zingiber officinalis Rosc

  13. Properties of the mitochondrial carrier of adenine-nucleotide after purification. Study of the transport protein under isolated form and reincorporated form in phospho-lipidic vesicles

    International Nuclear Information System (INIS)

    Brandolin, Gerard

    1983-01-01

    The first part of this research thesis addresses the reconstitution of the ADP/ATP transport by incorporation of the specific carrier, isolated in presence of detergent, in phospholipids vesicles. Fundamental properties of the reconstituted transport are identical to that of transport in mitochondria, notably as far as the exchange stoichiometry, the turn over and the transport Km are concerned, as well as the asymmetric orientation of the carrier in the membrane. The second part of this research addresses the study of interactions of specific ligands with the ADP/ATP transport protein in presence of detergent. The study of the variations of the intrinsic fluorescence of the isolated ADP/ATP carrier highlights conformational changes exclusively induced by the presence of transportable nucleotides which are modulated in a different manner by carboxy-atractyloside or bongkrekic acid. Moreover, by using the isolated protein, a detailed analysis of binding parameters of fluorescent analogues of ATP is reported [fr

  14. Antimicrobial properties of black grape (Vitis vinifera L.) peel extracts against antibiotic-resistant pathogenic bacteria and toxin producing molds.

    Science.gov (United States)

    Yadav, Devbrat; Kumar, Arvind; Kumar, Pramod; Mishra, Diwaker

    2015-01-01

    Black grape peel possesses a substantial amount of polyphenolic antimicrobial compounds that can be used for controlling the growth of pathogenic microorganisms. The purpose of this study was to assess antibacterial and antifungal activity of black grape peel extracts against antibiotic-resistant pathogenic bacteria and toxin producing molds, respectively. Peel of grape was subjected to polyphenolic extraction using different solvents viz., water, ethanol, acetone, and methanol. Antibiotic-resistant strains of Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella typhimurium, and Escherichia coli were screened for the antibacterial activity of different grape extracts. Antibacterial activity was analyzed using agar well diffusion method. Penicillium chrysogenum, Penicillium expansum, Aspergillus niger and Aspergillus versicolor were screened for the antifungal activity. Antifungal activity was determined by counting nongerminated spores in the presence of peel extracts. As compared to other solvent extracts, methanol extracts possessed high antibacterial and antifungal activity. S. typhimurium and E. coli showed complete resistance against antibacterial action at screened concentrations of grape peel extracts. Maximum zone of inhibition was found in case of S. aureus, i.e., 22 mm followed by E. faecalis and E. aerogenes, i.e., 18 and 21 mm, respectively, at 1080 mg tannic acid equivalent (TAE)/ml. The maximum and minimum percent of growth inhibition was shown by P. expansum and A. niger as 73% and 15% at 1080 TAE/ml concentration of grape peel extract, respectively. Except S. typhimurium and E. coli, growth of all bacterial and mold species were found to be significantly (P < 0.05) inhibited by all the solvent extracts.

  15. Fermentation of sarshir (kaymak) by lactic acid bacteria: antibacterial activity, antioxidant properties, lipid and protein oxidation and fatty acid profile.

    Science.gov (United States)

    Hashemi, Seyed Mohammad Bagher; Mousavi Khaneghah, Amin; Kontominas, Michael G; Eş, Ismail; Sant'Ana, Anderson S; Martinez, Rafael R; Drider, Djamel

    2017-10-01

    The antioxidant and antibacterial activities of fermented sarshir (traditional dairy food), with three probiotic Lactobacillus plantarum strains (LP3, AF1, and LU5), were investigated. The oxidative stability and the lipid profile of non-fermented and fermented sarshir were compared, in addition to radical scavenging activity, as well as peroxide, anisidine and carbonyl values (PV, AnV and CV, respectively). The strong antibacterial activity of fermented sarshir against common pathogenic bacteria, including Gram-negative Escherichia coli O157: H7 ATCC 35150 and Pseudomonas aeruginosa ATCC 27853, as well as Gram-positive Bacillus cereus ATCC 10876 and Staphylococcus aureus ATCC 25923, was established. Among the strains examined, L. plantarum LP3 exhibited the highest radical scavenging activity (53.1 ± 1.8%) and lowest PV (3.0 meq kg -1 ), AnV (1.31 ± 0.06) and CV (1.4 ± 0.08). The pH of sarshir decreased from 6.2 ± 0 to 3.5 ± 0.1 during 14 h of fermentation. Incorporated bacterial cells exhibited notable viability during 10 days of cold storage (4 °C). The fermentation of sarshir by L. plantarum strains, especially LP3, resulted in beneficial changes in radical scavenging activity, as well as PV, AnV and carbonyl values, in addition to a broad spectrum of inhibitory activity against strains of P. aeruginosa, E. coli O157:H7, B. cereus and S. aureus. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria.

    Science.gov (United States)

    Barbosa, Lidiane Nunes; Probst, Isabella da Silva; Andrade, Bruna Fernanda Murbach Teles; Alves, Fernanda Cristina Bérgamo; Albano, Mariana; da Cunha, Maria de Lourdes Ribeiro de Souza; Doyama, Julio Toshimi; Rall, Vera Lúcia Mores; Fernandes Júnior, Ary

    2015-01-01

    The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aromaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P. aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

  17. Extraction and purification of plutonium by a tertiary amine

    International Nuclear Information System (INIS)

    Trentinian, M. de; Chesne, A.; Commissariat a l'Energie Atomique, Saclay

    1960-01-01

    Trilaurylamine diluted with a paraffinic solvent (dodecane) was studied as part of the research dealing with the separation and purification of plutonium. The physical properties (solubility of nitrates in the amine as a function of temperature) and the resistance to radiations of this substance were examined. The extraction characteristics of nitric solutions of plutonium, uranium and certain fission products are given as a function of the following factors: concentration of the various ions in solution, valency states. A method of plutonium purification based on these results is presented. (author) [fr

  18. Magnetic Bacteria.

    Science.gov (United States)

    Nelson, Jane Bray; Nelson, Jim

    1992-01-01

    Describes the history of Richard Blakemore's discovery of magnetotaxic organisms. Discusses possible reasons why the magnetic response in bacteria developed. Proposes research experiments integrating biology and physics in which students investigate problems using cultures of magnetotaxic organisms. (MDH)

  19. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

  20. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

  1. Purification and biochemical properties of a thermostable, haloalkaline cellulase fromBacillus licheniformisAMF-07 and its application for hydrolysis of different cellulosic substrates to bioethanol production.

    Science.gov (United States)

    Azadian, Fatemeh; Badoei-Dalfard, Arastoo; Namaki-Shoushtari, Abdolhamid; Hassanshahian, Mehdi

    2016-09-01

    A thermophilic strain AMF-07, hydrolyzing carboxymethylcellulose (CMC) was isolated from Kerman hot spring and was identified as Bacillus licheniformis based on 16S rRNA sequence homology. The carboxymethylcellulase (CMCase) enzyme produced by the B. licheniformis was purified by (NH4)2SO4 precipitation, ion exchange and gel filtration chromatography. The purified enzyme gave a single band on SDS- PAGE with a molecular weight of 37 kDa. The CMCase enzyme was highly active and stable over broad ranges of temperature (40-80ºC), pH (6.0-10.0) and NaCl concentration (10-25%) with an optimum at 70ºC, pH 9.0 and 20% NaCl, which showed excellent thermostable, alkali-stable and halostable properties. Moreover, it displayed high activity in the presence of cyclohexane (134%) and chloroform (120%). Saccharification of rice bran and wheat bran by the CMCase enzyme resulted in respective yields of 24 and 32 g L-1 reducing sugars. The enzymatic hydrolysates of rice bran were then used as the substrate for ethanol production by Saccharomyces cerevisiae . Fermentation of cellulosic hydrolysate using S. cerevisiae , reached maximum ethanol production about 0.125 g g-1 dry substrate (pretreated wheat bran). Thus, the purified cellulase from B. licheniformis AMF-07 utilizing lignocellulosic biomass could be greatly useful to develop industrial processes.

  2. A Study of the Protective Properties of Iraqi Olive Leaves against Oxidation and Pathogenic Bacteria in Food Applications

    Directory of Open Access Journals (Sweden)

    Ammar B. Altemimi

    2017-05-01

    Full Text Available There is an ancient and prodigious history of olive trees because of their nutritional, medicinal, and traditional uses. Intensive studies have been conducted on olive leaves because they have many positive and beneficial effects for human health. In this study, different solvents were used to examine the olive leaves for their antioxidant and antimicrobial activities and their possible food applications. The obtained results showed that the amounts of phenolic compounds of the olive leaf were 190.44 ± 0.50, 173 ± 1.72, 147.78 ± 0.69, and 147.50 ± 0.05 mg gallic acid/g extracts using methanol, ethanol, diethyl ether, and hexanol, respectively. The statistical analysis revealed that there was a significant difference in the phenolic contents in terms of the used solvents. The stability of the olive leaves extraction was also studied and the results indicated that increasing the storage temperature could negatively affect and encourage the degradation of the phenolic compounds. Furthermore, the olive leaf extraction was applied to raw sheep meat slides at 0.5%, 1.5%, and 2.5% (w/v in order to test its antioxidant and antimicrobial effects. The results obviously showed that the sample treated with 2.5% olive leaf extract had the significantly (p < 0.05 lowest Thiobarbituric Acid (TBA values of 1.92 ± 0.12 (mg Malonaldehyde MDA/kg throughout 12 days of cold storage. Moreover, the results showed that the sample, which was treated with 2.5% olive leaf extract, had low total bacterial count and total coliform bacteria (6.23 ± 0.05, 5.2 ± 0.35 log colony forming unit (CFU/g, respectively among the control, 0.5%, and 1.5% olive leaf treated samples throughout 12 days of storage. The phenolic extracts from the olive leaf extract had significant antioxidant and antimicrobial activities, which could be used as a source of potential antioxidant and antimicrobial agents.

  3. Bromelain: an overview of industrial application and purification strategies.

    Science.gov (United States)

    Arshad, Zatul Iffah Mohd; Amid, Azura; Yusof, Faridah; Jaswir, Irwandi; Ahmad, Kausar; Loke, Show Pau

    2014-09-01

    This review highlights the use of bromelain in various applications with up-to-date literature on the purification of bromelain from pineapple fruit and waste such as peel, core, crown, and leaves. Bromelain, a cysteine protease, has been exploited commercially in many applications in the food, beverage, tenderization, cosmetic, pharmaceutical, and textile industries. Researchers worldwide have been directing their interest to purification strategies by applying conventional and modern approaches, such as manipulating the pH, affinity, hydrophobicity, and temperature conditions in accord with the unique properties of bromelain. The amount of downstream processing will depend on its intended application in industries. The breakthrough of recombinant DNA technology has facilitated the large-scale production and purification of recombinant bromelain for novel applications in the future.

  4. Purification and properties of a 3 alpha-hydroxysteroid dehydrogenase of rat liver cytosol and its inhibition by anti-inflammatory drugs.

    Science.gov (United States)

    Penning, T M; Mukharji, I; Barrows, S; Talalay, P

    1984-01-01

    An NAD(P)-dependent 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) was purified to homogeneity from rat liver cytosol, where it is responsible for most if not all of the capacity for the oxidation of androsterone, 1-acenaphthenol and benzenedihydrodiol (trans-1,2-dihydroxycyclohexa-3,5-diene). The dehydrogenase has many properties (substrate specificity, pI, Mr, amino acid composition) in common with the dihydrodiol dehydrogenase (EC 1.3.1.20) purified from the same source [Vogel, Bentley, Platt & Oesch (1980) J. Biol. Chem. 255, 9621-9625]. Since 3 alpha-hydroxysteroids are by far the most efficient substrates, the enzyme is more appropriately designated a 3 alpha-hydroxysteroid dehydrogenase. It also promotes the NAD(P)H-dependent reductions of quinones (e.g. 9,10-phenanthrenequinone, 1,4-benzoquinone), aromatic aldehydes (4-nitrobenzaldehyde) and aromatic ketones (4-nitroacetophenone). The dehydrogenase is not inhibited by dicoumarol, disulfiram, hexobarbital or pyrazole. The mechanism of the powerful inhibition of this enzyme by both non-steroidal and steroidal anti-inflammatory drugs [Penning & Talalay (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 4504-4508] was examined with several substrates. Most non-steroidal anti-inflammatory drugs are competitive inhibitors (e.g. Ki for indomethacin, 0.20 microM for 9,10-phenanthrenequinone reduction at pH 6.0, and 0.835 microM for androsterone oxidation at pH 7.0), except for salicylates, which act non-competitively (e.g. Ki for aspirin, 650 microM for androsterone oxidation). The inhibitory potency of these agents falls sharply as the pH is increased from 6 to 9. Most anti-inflammatory steroids are likewise competitive inhibitors, except for the most potent (betamethasone and dexamethasone), which act non-competitively. The enzyme is inhibited competitively by arachidonic acid and various prostaglandins. PMID:6435601

  5. Bacteria Provide Cleanup of Oil Spills, Wastewater

    Science.gov (United States)

    2010-01-01

    Through Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center, Micro-Bac International Inc., of Round Rock, Texas, developed a phototrophic cell for water purification in space. Inside the cell: millions of photosynthetic bacteria. Micro-Bac proceeded to commercialize the bacterial formulation it developed for the SBIR project. The formulation is now used for the remediation of wastewater systems and waste from livestock farms and food manufacturers. Strains of the SBIR-derived bacteria also feature in microbial solutions that treat environmentally damaging oil spills, such as that resulting from the catastrophic 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico.

  6. Probiotic properties of lactic acid bacteria isolated from stool samples of longevous people in regions of Hotan, Xinjiang and Bama, Guangxi, China.

    Science.gov (United States)

    Gu, Rui-Xia; Yang, Zhen-Quan; Li, Zheng-Hua; Chen, Shun-Li; Luo, Zhen-Lan

    2008-12-01

    A total of 567 lactic acid bacteria (LAB) strains were isolated from the stool samples of longevous people in regions of Hotan, Xinjiang and Bama, Guangxi, China. In order to reduce the number of strains for further examinations, 36 isolates were screened out for further examination whilst the other strains, which had lower probiotic properties, were not suitable for yogurt production due to the absence of growth in pH 3.5 MRS medium and no curding during fermentation, and so were excluded. The result of identification by API, sequence analysis of 16S rRNA and random amplified polymorphic DNA (RAPD) analysis showed that there were three strains of Lactobacillus acidophilus, 10 strains of Lactobacillus rhamnosus, three strains of Lactobacillus casein, three strains of Lactobacillus brevis, two strains of Enterococcus faecium, two strains of Enterococcus faecalis, four strains of Bifdibacterium infantis, three strains of Bifdibacterium brevise, three strains of Bifdibacterium bifidium, two strains of Bifdibacterium adolecentis and one strain of Bifdibacterium longam among the 36 isolates. These strains were evaluated by in vitro methods including survival upon exposure to pH 2.0, 3.0 and/or 0.3% oxgall and adhesion to the human colon adenocarcinoma cell line Caco-2 as well as antimicrobial activity against potential pathogens. The results presented here show that L. rhamnosus LV108, L. rhamnosus F, B. brevise R39 and B. infantis R42 are acid and bile tolerant, adhere to the cultured human intestinal Caco-2 cell line, antagonistic activity against potential pathogenic bacteria infection in vitro, and so are potential strains for probiotic use.

  7. Bacteria in the vaginal microbiome alter the innate immune response and barrier properties of the human vaginal epithelia in a species-specific manner.

    Science.gov (United States)

    Doerflinger, Sylvie Y; Throop, Andrea L; Herbst-Kralovetz, Melissa M

    2014-06-15

    Bacterial vaginosis increases the susceptibility to sexually transmitted infections and negatively affects women's reproductive health. To investigate host-vaginal microbiota interactions and the impact on immune barrier function, we colonized 3-dimensional (3-D) human vaginal epithelial cells with 2 predominant species of vaginal microbiota (Lactobacillus iners and Lactobacillus crispatus) or 2 prevalent bacteria associated with bacterial vaginosis (Atopobium vaginae and Prevotella bivia). Colonization of 3-D vaginal epithelial cell aggregates with vaginal microbiota was observed with direct attachment to host cell surface with no cytotoxicity. A. vaginae infection yielded increased expression membrane-associated mucins and evoked a robust proinflammatory, immune response in 3-D vaginal epithelial cells (ie, expression of CCL20, hBD-2, interleukin 1β, interleukin 6, interleukin 8, and tumor necrosis factor α) that can negatively affect barrier function. However, P. bivia and L. crispatus did not significantly upregulate pattern-recognition receptor-signaling, mucin expression, antimicrobial peptides/defensins, or proinflammatory cytokines in 3-D vaginal epithelial cell aggregates. Notably, L. iners induced pattern-recognition receptor-signaling activity, but no change was observed in mucin expression or secretion of interleukin 6 and interleukin 8. We identified unique species-specific immune signatures from vaginal epithelial cells elicited by colonization with commensal and bacterial vaginosis-associated bacteria. A. vaginae elicited a signature that is consistent with significant disruption of immune barrier properties, potentially resulting in enhanced susceptibility to sexually transmitted infections during bacterial vaginosis. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. Antibacterial Properties of Tebipenem Pivoxil Tablet, a New Oral Carbapenem Preparation against a Variety of Pathogenic Bacteria in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Qi Yao

    2016-01-01

    Full Text Available Aims: To systemically investigate the in vitro and in vivo antibacterial properties of tebipenem pivoxil tablet. In addition, acute toxicity of this preparation was also studied. Methods: In vitro, minimum inhibitory concentration (MIC or minimal inhibitory concentration (MBC were determined by using the serial 2-fold broth or agar dilution methods. Further, cumulative MIC inhibition curves were then made to assess the antibacterial effects of the drug at various concentrations. In vivo, minimum lethal dose (MLD in combination with maximum tolerance dose (MTD was used to measure the acute toxicity of the tebipenem pivoxil tablet in mice. After that, sepsis mouse models challenged with Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, respectively, were established to evaluate the anti-infective effect of this preparation. Results: The MIC90 values of tebipenem pivoxil against Gram-positive bacteria such as methicillin-sensitive Staphylococcus aureus (MSSA, methicillin-resistant Staphylococcus aureus (MRSA, methicillin-sensitive Staphylococcus epidermidis (MSSE, methicillin-resistant Staphylococcus epidermidis (MRSE, Pyogenic streptococcus, and Enterococcus faecalis were ≤0.125, 16, 0.5, 8, ≤0.125, and 32 μg/mL, respectively. Correspondingly, the MIC90 values of tebipenem pivoxil against Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, Haemophilus influenzae, Pseudomonas aeruginosa, and Acinetobacter baumannii were 1, 0.5, ≤0.125, 0.25, 64, 64 μg/mL, respectively. The MBC values of tebipenem pivoxil against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae were 0.016–2, 0.063–32, 0.031–32 μg/mL, respectively. The acute toxicity study showed that the MLD of the tebipenem pivoxil tablet was 4.00 g/kg and the MTD was 3.40 g/kg in mice. In all the sepsis mouse models, the simultaneous administration of the tebipenem pivoxil tablets significantly reduced mortality of

  9. Effect of freeze-drying on viability and in vitro probiotic properties of a mixture of lactic acid bacteria and yeasts isolated from kefir.

    Science.gov (United States)

    Bolla, Patricia A; Serradell, María de los Angeles; de Urraza, Patricio J; De Antoni, Graciela L

    2011-02-01

    The effect of freeze-drying on viability and probiotic properties of a microbial mixture containing selected bacterial and yeast strains isolated from kefir grains (Lactobacillus kefir, Lactobacillus plantarum, Lactococcus lactis, Saccharomyces cerevisiae and Kluyveromyces marxianus) was studied. The microorganisms were selected according to their potentially probiotic properties in vitro already reported. Two types of formulations were performed, a microbial mixture (MM) suspended in milk and a milk product fermented with MM (FMM). To test the effect of storage on viability of microorganisms, MM and FMM were freeze-dried and maintained at 4°C for six months. After 180 days of storage at 4°C, freeze-dried MM showed better survival rates for each strain than freeze-dried FMM. The addition of sugars (trehalose or sucrose) did not improve the survival rates of any of the microorganisms after freeze-drying. Freeze-drying did not affect the capacity of MM to inhibit growth of Shigella sonnei in vitro, since the co-incubation of this pathogen with freeze-dried MM produced a decrease of 2 log in Shigella viability. The safety of freeze-dried MM was tested in mice and non-translocation of microorganisms to liver or spleen was observed in BALB/c mice feed ad libitum during 7 or 20 days. To our knowledge, this is the first report about the effect of freeze-drying on viability, in vitro probiotic properties and microbial translocation of a mixture containing different strains of both bacteria and yeasts isolated from kefir.

  10. Stress tolerance, genetic analysis and symbiotic properties of root-nodulating bacteria isolated from Mediterranean leguminous shrubs in Central Spain.

    Science.gov (United States)

    Ruiz-Díez, Beatriz; Fajardo, Susana; Puertas-Mejía, Miguel Angel; de Felipe, María del Rosario; Fernández-Pascual, Mercedes

    2009-01-01

    Nine root-nodulating bacterial isolates were obtained from the leguminous shrubs Spartium junceum, Adenocarpus hispanicus, Cytisus purgans, Cytisus laburnuum, Retama sphaerocarpa and Colutea arborescens in areas of Central Spain. A poliphasic approach analyzing phenotypic, symbiotic and genetic properties was used to study their diversity and characterize them in relation to Mediterranean conditions. Stress tolerance assays revealed marked variations in salinity, extreme pH and cadmium tolerance compared with reference strains, with the majority showing salinity, alkalinity and Cd tolerance and three of them growing at acid pH. Variation within the 16S rRNA gene was examined by amplified 16S rDNA restriction analysis (ARDRA) and direct sequencing to show genetic diversity. Phylogeny confirmed the close relationship of four isolates with Bradyrhizobium canariense, three with Phylobacterium myrsinacearum, one with Rhizobium rhizogenes and another with Mesorhizobium huakuii. The cross inoculation tests revealed wide spectra of nodulation. This is the first report of P. myrsinacearum being able to nodulate these leguminous shrubs, and also the first time reported the association between B.canariense, R. rhizogenes and M. huakuii and C. laburnuum, C. purgans and C. arborescens, respectively. These results suggested that native rhizobia could be suitable candidates as biofertilizers and/or inoculants of leguminous shrubs with restoration or revegetation purposes in Mediterranean areas.

  11. A simple method for purification of lipopolysaccharides from E. coli 55:B5 using size exclusion chromatography

    International Nuclear Information System (INIS)

    Perdomo, Rolando; Montero, Vivian

    2006-01-01

    Several methods for the extraction of endotoxin or lipopolysaccharide from Gram negative bacteria have been described. However, the product is often contaminated with nucleic acids or proteins in a proportion depending on the extraction method used. Molecular and immunological studies require further purification of the raw LPS. We present here, a simple method for the purification of raw LPS obtained by the standard hot phenol-water procedure using size exclusion chromatography in Sepharose CL-6B. We demonstrated that the using of DNAse and RNAse treatment of the sample before the chromatographic step is necessary to abrogate the nucleic acid contamination in the LPS fraction. The spectrophotometric properties of the pure LPS were verified, supporting the immediate online detection of the LPS and oligonucleotides fractions spectrophotometrically at 206 nm. The mobile phase used (NaCl 0.2 M) do not absorb at 206 nm while maintains the LPS aggregates and therefore, allows the separation of the LPS fraction from the oligoribonucleotide and desoxioligoribonucleotide fractions. The yield of pure LPS was around 98%. Chemical and biological characterizations were conducted in order to assess the feasibility of the procedure developed. (Author)

  12. Genetic manipulation of the peptidolytic system in lactic acid bacteria

    NARCIS (Netherlands)

    Kok, J; Venema, G

    1995-01-01

    Due to their presumed involvenment in product flavour the peptidases of lactic acid bacteria have been subject to extensive research. A major breakthrough, was the isolation and purification of the various enzymes to homogeniety. This allowed a reevaluation of the number of different enzymes in one

  13. Purification and proteomics of pathogen-modified vacuoles and membranes.

    Science.gov (United States)

    Herweg, Jo-Ana; Hansmeier, Nicole; Otto, Andreas; Geffken, Anna C; Subbarayal, Prema; Prusty, Bhupesh K; Becher, Dörte; Hensel, Michael; Schaible, Ulrich E; Rudel, Thomas; Hilbi, Hubert

    2015-01-01

    Certain pathogenic bacteria adopt an intracellular lifestyle and proliferate in eukaryotic host cells. The intracellular niche protects the bacteria from cellular and humoral components of the mammalian immune system, and at the same time, allows the bacteria to gain access to otherwise restricted nutrient sources. Yet, intracellular protection and access to nutrients comes with a price, i.e., the bacteria need to overcome cell-autonomous defense mechanisms, such as the bactericidal endocytic pathway. While a few bacteria rupture the early phagosome and escape into the host cytoplasm, most intracellular pathogens form a distinct, degradation-resistant and replication-permissive membranous compartment. Intracellular bacteria that form unique pathogen vacuoles include Legionella, Mycobacterium, Chlamydia, Simkania, and Salmonella species. In order to understand the formation of these pathogen niches on a global scale and in a comprehensive and quantitative manner, an inventory of compartment-associated host factors is required. To this end, the intact pathogen compartments need to be isolated, purified and biochemically characterized. Here, we review recent progress on the isolation and purification of pathogen-modified vacuoles and membranes, as well as their proteomic characterization by mass spectrometry and different validation approaches. These studies provide the basis for further investigations on the specific mechanisms of pathogen-driven compartment formation.

  14. Purification of crime scene DNA extracts using centrifugal filter devices.

    Science.gov (United States)

    Norén, Lina; Hedell, Ronny; Ansell, Ricky; Hedman, Johannes

    2013-04-24

    The success of forensic DNA analysis is limited by the size, quality and purity of biological evidence found at crime scenes. Sample impurities can inhibit PCR, resulting in partial or negative DNA profiles. Various DNA purification methods are applied to remove impurities, for example, employing centrifugal filter devices. However, irrespective of method, DNA purification leads to DNA loss. Here we evaluate the filter devices Amicon Ultra 30 K and Microsep 30 K with respect to recovery rate and general performance for various types of PCR-inhibitory crime scene samples. Recovery rates for DNA purification using Amicon Ultra 30 K and Microsep 30 K were gathered using quantitative PCR. Mock crime scene DNA extracts were analyzed using quantitative PCR and short tandem repeat (STR) profiling to test the general performance and inhibitor-removal properties of the two filter devices. Additionally, the outcome of long-term routine casework DNA analysis applying each of the devices was evaluated. Applying Microsep 30 K, 14 to 32% of the input DNA was recovered, whereas Amicon Ultra 30 K retained 62 to 70% of the DNA. The improved purity following filter purification counteracted some of this DNA loss, leading to slightly increased electropherogram peak heights for blood on denim (Amicon Ultra 30 K and Microsep 30 K) and saliva on envelope (Amicon Ultra 30 K). Comparing Amicon Ultra 30 K and Microsep 30 K for purification of DNA extracts from mock crime scene samples, the former generated significantly higher peak heights for rape case samples (P-values crime scene samples and for consistency between different PCR-based analysis systems, such as quantification and STR analysis. In order to maximize the possibility to obtain complete STR DNA profiles and to create an efficient workflow, the level of DNA purification applied should be correlated to the inhibitor-tolerance of the STR analysis system used.

  15. Purification and physicochemical properties of - amylase from ...

    African Journals Online (AJOL)

    presence of maltose and maltodextrin but not glucose in the starch hydrolysate (2 h of reaction). This result indicated that the amylolytic enzyme of P. americana is an -amylase (an endoamylase). The purified -amylase hydrolysed maltopentose, maltohexose and maltoheptose. Maltose, maltotriose and maltotetrose were not ...

  16. Purification and biochemical properties of carboxylesterase from ...

    African Journals Online (AJOL)

    Carboxylesterase was purified from Fasciola gigantica through ammonium sulfate precipitation, chromatography on DEAE-Sepharose and gel filtration on a sephacryl S300. Three enzymes (EI, EII and EIII) were separated. EII and EIII were purified to homogeneity. The molecular weight of EII and EIII enzyme were 66 and ...

  17. RELIGION AND PURIFICATION OF SOUL

    Directory of Open Access Journals (Sweden)

    Azam Khodashenas Pelko

    2010-11-01

    Full Text Available The Jainism emphasizes three major teachings about the purification of the soul (jiva, Ahimsa, Aparigrapha and anekantwad. Jainism, The focus of this religion has been purification of the soul by means of right conduct, right faith and right knowledge. The ultimate goal of Hinduism is Moksha or liberation (total freedom. In Hinduism, purification of the soul is a goal that one must work to attain. The Buddhism is the science of pursuing the aim of making the human mind perfect, and of purifying the human soul. The knowledge of purifying of the soul and softening of the hearts is as essential for human. They having the correct motivations means purifying our souls from hypocrisy, caprice, and heedlessness. The primary goal of Taoism may be described as the mystical intuition of the Tao, which is the way, the undivided unity, and the ultimate Reality. According to the Christianity access to truth cannot be conceived without purity of the soul

  18. Effects of Single Amino Acid Substitution on the Biophysical Properties and Biological Activities of an Amphipathic α-Helical Antibacterial Peptide Against Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Juanjuan Tan

    2014-07-01

    Full Text Available An antimicrobial peptide, known as V13K, was utilized as the framework to study the effects of charge, hydrophobicity and helicity on the biophysical properties and biological activities of α-helical peptides. Six amino acids (Lys, Glu, Gly, Ser, Ala, and Leu were individually used to substitute the original hydrophobic valine at the selected sixteenth location on the non-polar face of V13K. The results showed that the single amino acid substitutions changed the hydrophobicity of peptide analogs as monitored by RP-HPLC, but did not cause significant changes on peptide secondary structures both in a benign buffer and in a hydrophobic environment. The biological activities of the analogs exhibited a hydrophobicity-dependent behavior. The mechanism of peptide interaction with the outer membrane and cytoplasmic membrane of Gram-negative bacteria was investigated. We demonstrated that this single amino acid substitution method has valuable potential for the rational design of antimicrobial peptides with enhanced activities.

  19. Site properties have a stronger influence than fire severity on ectomycorrhizal fungi and associated N-cycling bacteria in regenerating post-beetle-killed lodgepole pine forests.

    Science.gov (United States)

    Kennedy, Nabla M; Robertson, Susan J; Green, D Scott; Scholefield, Scott R; Arocena, Joselito M; Tackaberry, Linda E; Massicotte, Hugues B; Egger, Keith N

    2015-09-01

    Following a pine beetle epidemic in British Columbia, Canada, we investigated the effect of fire severity on rhizosphere soil chemistry and ectomycorrhizal fungi (ECM) and associated denitrifying and nitrogen (N)-fixing bacteria in the root systems of regenerating lodgepole pine seedlings at two site types (wet and dry) and three fire severities (low, moderate, and high). The site type was found to have a much larger impact on all measurements than fire severity. Wet and dry sites differed significantly for almost all soil properties measured, with higher values identified from wet types, except for pH and percent sand that were greater on dry sites. Fire severity caused few changes in soil chemical status. Generally, bacterial communities differed little, whereas ECM morphotype analysis revealed ectomycorrhizal diversity was lower on dry sites, with a corresponding division in community structure between wet and dry sites. Molecular profiling of the fungal ITS region confirmed these results, with a clear difference in community structure seen between wet and dry sites. The ability of ECM fungi to colonize seedlings growing in both wet and dry soils may positively contribute to subsequent regeneration. We conclude that despite consecutive landscape disturbances (mountain pine beetle infestation followed by wildfire), the "signature" of moisture on chemistry and ECM community structure remained pronounced.

  20. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  1. Partial Purification and Characterization of Extracellular Protease ...

    African Journals Online (AJOL)

    Nigerian Journal of Basic and Applied Sciences ... Purification of the enzyme by gel filtration chromatography on Sephadex G75 following ammonium sulphate precipitation gave 2.26 fold increase in purification with specific activity of 46.13 units/mg protein while purification on Sephadex CM50 resulted in reduced ...

  2. Online Oxide Contamination Measurement and Purification Demonstration

    Science.gov (United States)

    Bradley, D. E.; Godfroy, T. J.; Webster, K. L.; Garber, A. E.; Polzin, K. A.; Childers, D. J.

    2011-01-01

    Liquid metal sodium-potassium (NaK) has advantageous thermodynamic properties indicating its use as a fission reactor coolant for a surface (lunar, martian) power system. A major area of concern for fission reactor cooling systems is system corrosion due to oxygen contaminants at the high operating temperatures experienced. A small-scale, approximately 4-L capacity, simulated fission reactor cooling system employing NaK as a coolant was fabricated and tested with the goal of demonstrating a noninvasive oxygen detection and purification system. In order to generate prototypical conditions in the simulated cooling system, several system components were designed, fabricated, and tested. These major components were a fully-sealed, magnetically-coupled mechanical NaK pump, a graphite element heated reservoir, a plugging indicator system, and a cold trap. All system components were successfully demonstrated at a maximum system flow rate of approximately 150 cc/s at temperatures up to 550 C. Coolant purification was accomplished using a cold trap before and after plugging operations which showed a relative reduction in oxygen content.

  3. Macropis fulvipes Venom component Macropin Exerts its Antibacterial and Anti-Biofilm Properties by Damaging the Plasma Membranes of Drug Resistant Bacteria.

    Science.gov (United States)

    Ko, Su Jin; Kim, Min Kyung; Bang, Jeong Kyu; Seo, Chang Ho; Luchian, Tudor; Park, Yoonkyung

    2017-11-29

    The abuse of antibiotics for disease treatment has led to the emergence of multidrug resistant bacteria. Antimicrobial peptides, found naturally in various organisms, have received increasing interest as alternatives to conventional antibiotics because of their broad spectrum antimicrobial activity and low cytotoxicity. In a previous report, Macropin, isolated from bee venom, exhibited antimicrobial activity against both gram-positive and negative bacteria. In the present study, Macropin was synthesized and its antibacterial and anti-biofilm activities were tested against bacterial strains, including gram-positive and negative bacteria, and drug resistant bacteria. Moreover, Macropin did not exhibit hemolytic activity and cytotoxicity to keratinocytes, whereas Melittin, as a positive control, showed very high toxicity. Circular dichroism assays showed that Macropin has an α-helical structure in membrane mimic environments. Macropin binds to peptidoglycan and lipopolysaccharide and kills the bacteria by disrupting their membranes. Moreover, the fractional inhibitory concentration index indicated that Macropin has additive and partially synergistic effects with conventional antibiotics against drug resistant bacteria. Thus, our study suggested that Macropin has potential for use of an antimicrobial agent for infectious bacteria, including drug resistant bacteria.

  4. The effect of pyrite on Escherichia coli in water: proof-of-concept for the elimination of waterborne bacteria by reactive minerals.

    Science.gov (United States)

    Friedlander, Lonia R; Puri, Neha; Schoonen, Martin A A; Wali Karzai, A

    2015-03-01

    We present proof-of-concept results for the elimination of waterborne bacteria by reactive minerals. We exposed Escherichia coli MG1655 suspended in water to the reactive mineral pyrite (FeS₂) at room temperature and ambient light. This slurry eliminates 99.9% of bacteria in fewer than 4 hours. We also exposed Escherichia coli to pyrite leachate (supernatant liquid from slurry after 24 hours), which eliminates 99.99% of bacteria over the same time-scale. Unlike SOlar water DISinfection (SODIS), our results do not depend on the presence of ultraviolet (UV) light. We confirmed this by testing proposed SODIS additive and known photo-catalyst anatase (TiO₂) for antibacterial properties and found that, in contrast to pyrite, it does not eliminate E. coli under our experimental conditions. Previous investigations of naturally antibiotic minerals have focused on the medical applications of antibiotic clays, and thus have not been conducted under experimental conditions resembling those found in water purification. In our examination of the relevant literature, we have not found previously reported evidence for the use of reactive minerals in water sanitization. The results from this proof-of-concept experiment may have important implications for future directions in household water purification research.

  5. PURIFICATION AND CHARACTERISATION OF ALKALINE ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    phosphatase activity upon phosphate deprivation with much of the enzyme released into the medium during osmotic shock, indicating .... shaking. Protein purification. Three millilitres of overnight culture (400 ml) was harvested by centrifugation at 6000x g for 1 min. The supernatant was decanted and pellet washed twice in ...

  6. Nanocellulose-Based Materials for Water Purification.

    Science.gov (United States)

    Voisin, Hugo; Bergström, Lennart; Liu, Peng; Mathew, Aji P

    2017-03-05

    Nanocellulose is a renewable material that combines a high surface area with high strength, chemical inertness, and versatile surface chemistry. In this review, we will briefly describe how nanocellulose is produced, and present-in particular, how nanocellulose and its surface modified versions affects the adsorption behavior of important water pollutants, e.g., heavy metal species, dyes, microbes, and organic molecules. The processing of nanocellulose-based membranes and filters for water purification will be described in detail, and the uptake capacity, selectivity, and removal efficiency will also be discussed. The processing and performance of nanocellulose-based membranes, which combine a high removal efficiency with anti-fouling properties, will be highlighted.

  7. Nanocellulose-Based Materials for Water Purification

    Directory of Open Access Journals (Sweden)

    Hugo Voisin

    2017-03-01

    Full Text Available Nanocellulose is a renewable material that combines a high surface area with high strength, chemical inertness, and versatile surface chemistry. In this review, we will briefly describe how nanocellulose is produced, and present—in particular, how nanocellulose and its surface modified versions affects the adsorption behavior of important water pollutants, e.g., heavy metal species, dyes, microbes, and organic molecules. The processing of nanocellulose-based membranes and filters for water purification will be described in detail, and the uptake capacity, selectivity, and removal efficiency will also be discussed. The processing and performance of nanocellulose-based membranes, which combine a high removal efficiency with anti-fouling properties, will be highlighted.

  8. A Straightforward Access to New Families of Lipophilic Polyphenols by Using Lipolytic Bacteria.

    Science.gov (United States)

    Sánchez-Barrionuevo, Leyre; González-Benjumea, Alejandro; Escobar-Niño, Almudena; García, María Teresa; López, Óscar; Maya, Inés; Fernández-Bolaños, José G; Cánovas, David; Mellado, Encarnación

    2016-01-01

    The chemical synthesis of new lipophilic polyphenols with improved properties presents technical difficulties. Here we describe the selection, isolation and identification of lipolytic bacteria from food-processing industrial wastes, and their use for tailoring a new set of compounds with great interest in the food industry. These bacteria were employed to produce lipolytic supernatants, which were applied without further purification as biocatalysts in the chemoselective and regioselective synthesis of lipophilic partially acetylated phenolic compounds derived from olive polyphenols. The chemoselectivity of polyphenols acylation/deacylation was analyzed, revealing the preference of the lipases for phenolic hydroxyl groups and phenolic esters. In addition, the alcoholysis of peracetylated 3,4-dihydroxyphenylglycol resulted in a series of lipophilic 2-alkoxy-2-(3,4-dihydroxyphenyl)ethyl acetate through an unexpected lipase-mediated etherification at the benzylic position. These new compounds are more lipophilic and retained their antioxidant properties. This approach can provide access to unprecedented derivatives of 3,4-dihydroxyphenylglycol with improved properties.

  9. A Straightforward Access to New Families of Lipophilic Polyphenols by Using Lipolytic Bacteria.

    Directory of Open Access Journals (Sweden)

    Leyre Sánchez-Barrionuevo

    Full Text Available The chemical synthesis of new lipophilic polyphenols with improved properties presents technical difficulties. Here we describe the selection, isolation and identification of lipolytic bacteria from food-processing industrial wastes, and their use for tailoring a new set of compounds with great interest in the food industry. These bacteria were employed to produce lipolytic supernatants, which were applied without further purification as biocatalysts in the chemoselective and regioselective synthesis of lipophilic partially acetylated phenolic compounds derived from olive polyphenols. The chemoselectivity of polyphenols acylation/deacylation was analyzed, revealing the preference of the lipases for phenolic hydroxyl groups and phenolic esters. In addition, the alcoholysis of peracetylated 3,4-dihydroxyphenylglycol resulted in a series of lipophilic 2-alkoxy-2-(3,4-dihydroxyphenylethyl acetate through an unexpected lipase-mediated etherification at the benzylic position. These new compounds are more lipophilic and retained their antioxidant properties. This approach can provide access to unprecedented derivatives of 3,4-dihydroxyphenylglycol with improved properties.

  10. Investigation of potential antibacterial properties of methanol extracts from fungus Ganoderma applanatum.

    Science.gov (United States)

    Moradali, Mohammad-Fata; Mostafavi, Hossien; Hejaroude, Ghorban-Ali; Tehrani, Abbas Sharifi; Abbasi, Mehrdad; Ghods, Shirin

    2006-01-01

    In this study we searched for antibacterial compounds in methanol extracts of three layers (tube layer, context and cutis) of Ganoderma applanatum fruit body against Bacillus subtilis ATCC 6051 as a gram-positive bacterium and Escherichia coli ATCC 25922 and Pseudomonas syringae pv. syringae DPIC 219 as gram-negative bacteria. We found antibacterial properties in all three layers only against gram-negative bacteria. The fractions were isolated and purified by thin layer chromatography (TLC) and high-performance liquid chromatography. After purification, four major compounds - A, B, C and D - were tested for antibacterial properties, and B and D were found to possess antibacterial properties. The results of TLC and spectral data, including mass spectra and (1)H NMR of compounds B and C, showed that they were saturated fatty acids and compound D was palmitic acid (hexadecanoic acid) (16:0).

  11. Diversity and technological properties of predominant lactic acid bacteria from fermented cassava used for the preparation of Gari, a traditional African food

    CSIR Research Space (South Africa)

    Kostinek, M

    2005-08-01

    Full Text Available Traditional fermentation of cassava is dominated by a lactic acid bacteria (LAB) population. Fermentation is important for improving product flavour and aroma as well as safety, especially by reduction of its toxic cyanogenic glycosides...

  12. Beating Back Bacteria

    Science.gov (United States)

    1998-01-01

    Under a NASA-Johnson Space Center contract, Umpqua Research developed the MCV (Trademark) (Microbial Check Valve) which uses iodinated ion exchange resin used for water purification systems aboard space missions. Using this resin, MRLB International, Inc., developed and commercialized the Dentapure purification cartridge used by dentists nationwide.

  13. Tensile deformation of polytetrafluoroethylene hollow fiber membranes used for water purification.

    Science.gov (United States)

    Yonezu, Akio; Iio, Shouichi; Itonaga, Takehiro; Yamamura, Hiroshi; Chen, Xi

    2014-01-01

    The tensile deformation behavior of polytetrafluoroethylene (PTFE) hollow fiber membranes is studied. PTFE membranes at present have sub-micron pores with an open cell structure, which plays a critical role in water purification. One of the main challenges in water purification is that the pore structure becomes covered with biofouling, leading to blocked pores. To maintain the capacity for water purification, physical cleaning along with mechanical deformation is usually conducted. Thus, it is crucial to understand the mechanical properties, in particular the deformation behavior, of the membrane fibers. Using uniaxial tension experiments, we established a fundamental discrete model to describe the deformation behavior of a porous structure using a finite element method. The present model enables the prediction of the macroscopic deformation behavior of the membrane, by taking into account the changes of pore structure. The insight may be useful for porous membrane fabrication and provide insights for the reliable operation of water purification.

  14. Statistical and Judgmental Criteria for Scale Purification

    DEFF Research Database (Denmark)

    Wieland, Andreas; Durach, Christian F.; Kembro, Joakim

    2017-01-01

    of scale purification, to critically analyze the current state of scale purification in supply chain management (SCM) research and to provide suggestions for advancing the scale-purification process. Design/methodology/approach A framework for making scale-purification decisions is developed and used......Purpose “Scale purification” – the process of eliminating items from multi-item scales – is widespread in empirical research, but studies that critically examine the implications of this process are scarce. The goals of this research are threefold: to discuss the methodological underpinning...... to analyze and critically reflect on the application of scale purification in leading SCM journals. Findings This research highlights the need for rigorous scale-purification decisions based on both statistical and judgmental criteria. By applying the proposed framework to the SCM discipline, a lack...

  15. Water purification using organic salts

    Science.gov (United States)

    Currier, Robert P.

    2004-11-23

    Water purification using organic salts. Feed water is mixed with at least one organic salt at a temperature sufficiently low to form organic salt hydrate crystals and brine. The crystals are separated from the brine, rinsed, and melted to form an aqueous solution of organic salt. Some of the water is removed from the aqueous organic salt solution. The purified water is collected, and the remaining more concentrated aqueous organic salt solution is reused.

  16. Technological assumptions for biogas purification.

    Science.gov (United States)

    Makareviciene, Violeta; Sendzikiene, Egle

    2015-01-01

    Biogas can be used in the engines of transport vehicles and blended into natural gas networks, but it also requires the removal of carbon dioxide, hydrogen sulphide, and moisture. Biogas purification process flow diagrams have been developed for a process enabling the use of a dolomite suspension, as well as for solutions obtained by the filtration of the suspension, to obtain biogas free of hydrogen sulphide and with a carbon dioxide content that does not exceed 2%. The cost of biogas purification was evaluated on the basis of data on biogas production capacity and biogas production cost obtained from local water treatment facilities. It has been found that, with the use of dolomite suspension, the cost of biogas purification is approximately six times lower than that in the case of using a chemical sorbent such as monoethanolamine. The results showed travelling costs using biogas purified by dolomite suspension are nearly 1.5 time lower than travelling costs using gasoline and slightly lower than travelling costs using mineral diesel fuel.

  17. Purification and characterization of two sugarcane bagasse-absorbable thermophilic xylanases from the mesophilic Cellulomonas flavigena.

    Science.gov (United States)

    Santiago-Hernández, Alejandro; Vega-Estrada, Jesús; del Carmen Montes-Horcasitas, María; Hidalgo-Lara, María Eugenia

    2007-04-01

    We report the purification and characterization of two thermophilic xylanases from the mesophilic bacteria Cellulomonas flavigena grown on sugarcane bagasse (SCB) as the only carbon source. Extracellular xylanase activity produced by C. flavigena was found both free in the culture supernatant and associated with residual SCB. To identify some of the molecules responsible for the xylanase activity in the substrate-bound fraction, residual SCB was treated with 3 M guanidine hydrochloride and then with 6 M urea. Further analysis of the eluted material led to the identification of two xylanases Xyl36 (36 kDa) and Xyl53 (53 kDa). The pI for Xyl36 was 5.0, while the pI for Xyl53 was 4.5. Xyl36 had a Km value of 1.95 mg/ml, while Xyl53 had a Km value of 0.78 mg/ml. In addition to SCB, Xyl36 and Xyl53 were also able to bind to insoluble oat spelt xylan and Avicel, as shown by substrate-binding assays. Xyl36 and Xyl53 showed optimal activity at pH 6.5, and at optimal temperature 65 and 55 degrees C, respectively. Xyl36 and Xyl53 retained 24 and 35%, respectively, of their original activity after 8 h of incubation at their optimal temperature. As far as we know, this is the first study on the thermostability properties of purified xylanases from microorganisms belonging to the genus Cellulomonas.

  18. Influence of the drying method in chitosans purification step

    International Nuclear Information System (INIS)

    Fonseca, Ana C.M.; Batista, Jorge G.S.; Bettega, Antonio; Lima, Nelson B. de

    2015-01-01

    Currently, the study of extracellular biopolymers properties has received prominence for being easy extraction and purification. Chitosan has been an attractive proposition for applications in various fields such as engineering, biotechnology, medicine and pharmacology. For such applications, it is necessary purification of chitosan to obtain a product more concentrated and free of undesirable impurities. However, at this stage of the process of obtaining the biopolymer may occur morphological and physicochemical changes. This study evaluated the influence of the drying process after purification of a commercial chitosan sample and the importance of this step and its cost/benefit in applications requiring a high degree of purity. The method of drying influenced in the organoleptic properties and in the main characteristics of material. Analysis of the crystal structure by X-ray diffraction showed that the degree of crystallinity, X (%), in the purified chitosan samples was lower when compared with the unpurified sample. The degree of acetylation, DA (%), was analyzed by spectroscopy infrared with no significant changes on the three drying methods assessed, unlike the viscosimetric molecular weight, M v , determined by capillary viscometry. (author)

  19. Comparing Russian and Finnish standards of water purification

    OpenAIRE

    Maria, Pupkova

    2012-01-01

    The subject of this thesis is water purification. The first aim of this thesis is to consider different ways of water purification. The second aim is to compare Finnish and Russian standards of water purification. The third one is to show water purification methods on the pattern of Mikkeli water purification plan. Water purification methods of water intended for human consumption will be described.Combined tables will be done according to the quality requirement of drinking water of both,...

  20. Uranium hexafluoride purification; Purificacao de hexafluoreto de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Eneas F. de

    1986-07-01

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF{sub 6}-HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF{sub 6}-HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  1. Antibody Fragments and Their Purification by Protein L Affinity Chromatography

    Directory of Open Access Journals (Sweden)

    Gustav Rodrigo

    2015-09-01

    Full Text Available Antibodies and related proteins comprise one of the largest and fastest-growing classes of protein pharmaceuticals. A majority of such molecules are monoclonal antibodies; however, many new entities are antibody fragments. Due to their structural, physiological, and pharmacological properties, antibody fragments offer new biopharmaceutical opportunities. In the case of recombinant full-length antibodies with suitable Fc regions, two or three column purification processes centered around Protein A affinity chromatography have proven to be fast, efficient, robust, cost-effective, and scalable. Most antibody fragments lack Fc and suitable affinity for Protein A. Adapting proven antibody purification processes to antibody fragments demands different affinity chromatography. Such technology must offer the unit operation advantages noted above, and be suitable for most of the many different types of antibody fragments. Protein L affinity chromatography appears to fulfill these criteria—suggesting its consideration as a key unit operation in antibody fragment processing.

  2. Direct osmosis method of purification and desalination of drinking water

    International Nuclear Information System (INIS)

    Khaydarov, R.A.; Khaydarov, R.R.

    2005-01-01

    Full text: Drinking water quality is one of the general factors influencing people's health. The human activity in industry and agriculture has led to pollution of the environment: soil, air, both surface and ground waters that are polluted with chemical substances. It has a disastrous effect on the health of the population, especially of children. At present, the known equipment, based on ion exchange, electrodialysis and reverse osmosis, require great expense, energy expenditures, and highly qualified personnel that are inaccessible to the population especially living in remote regions. Methods, which are usually used in water supplying plants, cannot remove spore forms of bacteria and many types of chemical substances. The purpose of this Project is to create an absolutely new method for purification of drinking water from chemical and biological agents. The method is based on using direct osmosis process that removes all contaminants except one and removing last contaminant. This method will be used for making new low energy-consuming and cheap mini-systems for individual and collective use for desalination of drinking water and purification from bacteria, radionuclides, heavy metal ions, and organic contaminants. Preliminary experiments and calculations conducted in Uzbekistan show that the energy consumption is 0.8 MW per 1 m 3 of water. Advantage of the method is low energy consumption, potentially purifying water without pretreatment and removing different types of bacteria including spore forms, radionuclides, heavy metal ions, organic contaminants. Devices can be powered by solar units in remote locations. The purpose of this work is further elaboration of this technology creation of new method and its accommodation to conditions of different countries. Test models will be made and tested in laboratories of interested countries

  3. Purification of uranium metal

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Shikama, Tatsuo; Ochiai, Akira.

    1993-01-01

    We developed the system for purifying uranium metal and its metallic compounds and for growing highly pure uranium compounds to study their intrinsic physical properties. Uranium metal was zone refined under low contamination conditions as far as possible. The degree of the purity of uranium metal was examined by the conventional electrical resistivity measurement and by the chemical analysis using the inductive coupled plasma emission spectrometry (ICP). The results show that some metallic impurities evaporated by the r.f. heating and other usual metallic impurities moved to the end of a rod with a molten zone. Therefore, we conclude that the zone refining technique is much effective to the removal of metallic impurities and we obtained high purified uranium metal of 99.99% up with regarding to metallic impurities. The maximum residual resistivity ratio, the r.r.r., so far obtained was about 17-20. Using the purified uranium, we are attempting to grow a highly pure uranium-titanium single crystals. (author)

  4. Enhanced antiadhesive properties of chitosan/hyaluronic acid polyelectrolyte multilayers driven by thermal annealing: Low adherence for mammalian cells and selective decrease in adhesion for Gram-positive bacteria.

    Science.gov (United States)

    Muzzio, Nicolás E; Pasquale, Miguel A; Diamanti, Eleftheria; Gregurec, Danijela; Moro, Marta Martinez; Azzaroni, Omar; Moya, Sergio E

    2017-11-01

    The development of antifouling coatings with restricted cell and bacteria adherence is fundamental for many biomedical applications. A strategy for the fabrication of antifouling coatings based on the layer-by-layer assembly and thermal annealing is presented. Polyelectrolyte multilayers (PEMs) assembled from chitosan and hyaluronic acid were thermally annealed in an oven at 37°C for 72h. The effect of annealing on the PEM properties and topography was studied by atomic force microscopy, ζ-potential, circular dichroism and contact angle measurements. Cell adherence on PEMs before and after annealing was evaluated by measuring the cell spreading area and aspect ratio for the A549 epithelial, BHK kidney fibroblast, C2C12 myoblast and MC-3T3-E1 osteoblast cell lines. Chitosan/hyaluronic acid PEMs show a low cell adherence that decreases with the thermal annealing, as observed from the reduction in the average cell spreading area and more rounded cell morphology. The adhesion of S. aureus (Gram-positive) and E. coli (Gram-negative) bacteria strains was quantified by optical microscopy, counting the number of colony-forming units and measuring the light scattering of bacteria suspension after detachment from the PEM surface. A 20% decrease in bacteria adhesion was selectively observed in the S. aureus strain after annealing. The changes in mammalian cell and bacteria adhesion correlate with the changes in topography of the chitosan/hyaluronic PEMs from a rough fibrillar 3D structure to a smoother and planar surface after thermal annealing. Copyright © 2017. Published by Elsevier B.V.

  5. Continuous Purification of Colloidal Quantum Dots in Large-Scale Using Porous Electrodes in Flow Channel

    Science.gov (United States)

    Lim, Hosub; Woo, Ju Young; Lee, Doh Chang; Lee, Jinkee; Jeong, Sohee; Kim, Duckjong

    2017-11-01

    Colloidal Quantum dots (QDs) afford huge potential in numerous applications owing to their excellent optical and electronic properties. After the synthesis of QDs, separating QDs from unreacted impurities in large scale is one of the biggest issues to achieve scalable and high performance optoelectronic applications. Thus far, however, continuous purification method, which is essential for mass production, has rarely been reported. In this study, we developed a new continuous purification process that is suitable to the mass production of high-quality QDs. As-synthesized QDs are driven by electrophoresis in a flow channel and captured by porous electrodes and finally separated from the unreacted impurities. Nuclear magnetic resonance and ultraviolet/visible/near-infrared absorption spectroscopic data clearly showed that the impurities were efficiently removed from QDs with the purification yield, defined as the ratio of the mass of purified QDs to that of QDs in the crude solution, up to 87%. Also, we could successfully predict the purification yield depending on purification conditions with a simple theoretical model. The proposed large-scale purification process could be an important cornerstone for the mass production and industrial use of high-quality QDs.

  6. Engineering a recyclable elastin-like polypeptide capturing scaffold for non-chromatographic protein purification.

    Science.gov (United States)

    Liu, Fang; Chen, Wilfred

    2013-01-01

    Previously, we reported a non-chromatographic protein purification method exploiting the highly specific interaction between the dockerin and cohesin domains from Clostridium thermocellum and the reversible aggregation property of elastin-like polypeptide (ELP) to provide fast and cost-effective protein purification. However, the bound dockerin-intein tag cannot be completely dissociated from the ELP-cohesin capturing scaffold due to the high binding affinity, resulting in a single-use approach. In order to further reduce the purification cost by recycling the ELP capturing scaffold, a truncated dockerin domain with the calcium-coordinating function partially impaired was employed. We demonstrated that the truncated dockerin domain was sufficient to function as an effective affinity tag, and the target protein was purified directly from cell extracts in a single binding step followed by intein cleavage. The efficient EDTA-mediated dissociation of the bound dockerin-intein tag from the ELP-cohesin capturing scaffold was realized, and the regenerated ELP capturing scaffold was reused in another purification cycle without any decrease in the purification efficiency. This recyclable non-chromatographic based affinity method provides an attractive approach for efficient and cost-effective protein purification. © 2013 American Institute of Chemical Engineers.

  7. Commercial Charcoal Characterisation For Water Purification

    International Nuclear Information System (INIS)

    Saryati; Sumardjo; Sutisna; Handayani, Ari; Suprapti, Siti

    2001-01-01

    In order to provide a drinking water purification substance, has been studied the charcoal characterisation that based on a porous profile and an adsorption properties of the charcoal. There were using the commercial charcoal like wood charcoals, coconut shell charcoals and activated charcoals. The porous profile was studied by using an electron microscope SEM-EDX and the adsorption properties was studied by using the water sample simulation that contains several metal ions. The concentration of all ions was ten times greater that the maximum ions concentration that permissible in the drinking water. From the grain surface microscopic analysis was shown that the pore structure of the wood charcoal was more regular than the coconut shell charcoal. Mean while the activated charcoal has pore more than wood and coconut shell charcoal. Grains size was not an adsorption parameter. The absorptivitas charcoal was affected by pH solution, but this effect was not linear proportion. There are no significant deference in the adsorptivitas among the tree charcoals that has been studied for Al 3 + , Cr 3+ , Ag 1 +, and Pb 2+ ions the adsorption was large enough (> 60%), for Mn 2+ , Fe 3+ , Se 4+ , Cd 2+ and Ba 2+ ions was 20%-60% dan for Mg 2+ , Na 1+ , Ca 2+ , and Zn 2+ ions was less than 20 %. Generally the wood and coconut shell charcoal absorptivity in the pH 4 solutions was lower than in the pH 5-7 solutions

  8. Purification of rhamnolipid using colloidal magnetic nanoparticles ...

    African Journals Online (AJOL)

    Phospholipid-coated colloidal magnetic nanoparticles with mean magnetite core size of 9 nm are shown to be effective ion exchange media for the recovery and purification of Rhaminolipid from culture mixtures. These particles have high adsorption capacity for purification (an order of magnitude larger than the best ...

  9. Purification and characterization of amidase from acrylamide ...

    African Journals Online (AJOL)

    An amidase from a newly isolated acrylamide-degrading bacterium Burkholderia sp. strain DR.Y27 was purified to homogeneity by a combination of anion exchange and gel filtration chromatography. The purification strategy achieved 11.15 of purification fold and a yield of 1.55%. The purified amidase consisted of four ...

  10. Ion exchange purification of scandium

    Science.gov (United States)

    Herchenroeder, L.A.; Burkholder, H.R.

    1990-10-23

    An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity. 2 figs.

  11. Method for purification of gases

    Energy Technology Data Exchange (ETDEWEB)

    Hastrup, N.E.

    1981-11-17

    The present invention is directed to a method for selective purification of gases. The method comprises feeding an exhaust gas containing a solid impurity and a gaseous impurity to a separator. A substantial portion of the solid impurity is separated. Then, the partially-purified gas is fed to a spray dryer. That gas is sprayed with an absorption agent to separate gaseous impurities. Then, the further, partially-purified gas is fed to another separator to separate remaining solid impurity. An exhaust gas which is substantially free of solid and gaseous impurities and fly ash having a desired quality are recovered.

  12. THE PURIFICATION OF HYPERTENSIN I

    Science.gov (United States)

    Skeggs, Leonard T.; Marsh, Walton H.; Kahn, Joseph R.; Shumway, Norman P.

    1954-01-01

    The purification of hypertensin I has been described. The final product which is four times as powerful a pressor agent as l-arterenol, is obtained with an over-all recovery of 40 per cent. The product consists of a single component in countercurrent distribution, having a nitrogen content of 15.97 per cent and a specific activity of 7050 Goldblatt units per mg. of N or 1125 units per mg. of solid. Acid hydrolysis and paper chromatography indicate in a preliminary fashion that there are about nine amino acids present in the intact polypeptide. PMID:13201713

  13. Assessing the yield, microstructure, and texture properties of miniature Chihuahua-type cheese manufactured with a phospholipase A1 and exopolysaccharide-producing bacteria.

    Science.gov (United States)

    Trancoso-Reyes, N; Gutiérrez-Méndez, N; Sepulveda, D R; Hernández-Ochoa, L R

    2014-02-01

    Chihuahua cheese or Mennonite cheese is one of the most popular and consumed cheeses in Mexico and by the Hispanic community in the United States. According to local producers the yield of Chihuahua cheese ranges from 9 to 9.5 kg of cheese from 100 kg of milk. Cheese yield is a crucial determinant of profitability in cheese-manufacturing plants; therefore, different methods have been developed to increase it. In this work, a miniature Chihuahua-type cheese model was used to assess the effect of a phospholipase A1 (PL-A1) and exopolysaccharide (EPS)-producing bacteria (separately and in combination) on the yield, microstructure, and texture of cheese. Four different cheeses were manufactured: cheese made with PL-A1, cheese made with EPS-producing bacteria, cheese with both PL-A1 and EPS-producing bacteria, and a cheese control without PL-A1 or EPS-producing bacteria. The compositional analysis of cheese was carried out using methods of AOAC International (Washington, DC). The actual yield and moisture-adjusted yield were calculated for all cheese treatments. Texture profile analyses of cheeses were performed using a texture analyzer. Micrographs were obtained by electron scanning microscopy. Fifty panelists carried out sensorial analysis using ranking tests. Incorporation of EPS-producing bacteria in the manufacture of cheese increased the moisture content and water activity. In contrast, the addition of PL-A1 did not increase fat retention or cheese yield. The use of EPS alone improved the cheese yield by increasing water and fat retention, but also caused a negative effect on the texture and flavor of Chihuahua cheese. The use of EPS-producing bacteria in combination with PL-A1 improved the cheese yield and increased the moisture and fat content. The cheeses with the best flavor and texture were those manufactured with PL-A1 and the cheeses manufactured with the combination of PL-A1 and EPS-producing culture. Copyright © 2014 American Dairy Science Association

  14. Preparative Purification of Liriodendrin from Sargentodoxa cuneata by Macroporous Resin

    Science.gov (United States)

    Li, Di-Hua; Wang, Yan; Lv, Yuan-Shan; Liu, Jun-Hong; Yang, Lei; Zhang, Shu-Kun; Zhuo, Yu-Zhen

    2015-01-01

    The preparative purification of liriodendrin from Sargentodoxa cuneata using macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/desorption tests were performed using a glass column packed with X-5 resin to optimize the separation process of liriodendrin. After one treatment with X-5 resin, the content of liriodendrin in the product was increased 48.73-fold, from 0.85% to 41.42%, with a recovery yield of 88.9%. 97.48% liriodendrin was obtained by further crystallization and determined by HPLC. The purified product possessed strong antioxidant activity. In conclusion, purification of liriodendrin might expend its further pharmacological researches and further applications in pharmacy. PMID:26236742

  15. A comprehensive review on biodiesel purification and upgrading

    Directory of Open Access Journals (Sweden)

    Hamed Bateni

    2017-09-01

    Full Text Available Serious environmental concerns regarding the use of fossil-based fuels have raised awareness regarding the necessity of alternative clean fuels and energy carriers. Biodiesel is considered a clean, biodegradable, and non-toxic diesel substitute produced via the transesterification of triglycerides with an alcohol in the presence of a proper catalyst. After initial separation of the by-product (glycerol, the crude biodiesel needs to be purified to meet the standard specifications prior to marketing. The presence of impurities in the biodiesel not only significantly affects its engine performance but also complicates its handling and storage. Therefore, biodiesel purification is an essential step prior to marketing. Biodiesel purification methods can be classified based on the nature of the process into equilibrium-based, affinity-based, membrane-based, reaction-based, and solid-liquid separation processes. The main adverse properties of biodiesel – namely moisture absorption, corrosiveness, and high viscosity – primarily arise from the presence of oxygen. To address these issues, several upgrading techniques have been proposed, among which catalytic (hydrodeoxygenation using conventional hydrotreating catalysts, supported metallic materials, and most recently transition metals in various forms appear promising. Nevertheless, catalyst deactivation (via coking and/or inadequacy of product yields necessitate further research. This paper provides a comprehensive overview on the techniques and methods used for biodiesel purification and upgrading.

  16. Quantification of bacteria on abiotic surfaces by laser scanning cytometry: An automated approach to screen the antifouling properties of new surface coatings

    DEFF Research Database (Denmark)

    Regina, Viduthalai R.; Poulsen, Morten; Søhoel, Helmer

    2012-01-01

    . Among the coatings tested, a significant reduction in adhesion of S. xylosus was only observed for one coating, which also had a unique surface micro-structure. LSC was particularly sensitive for quantification at low cell densities, and the adhered bacteria could be quantified both as cell number...... and as area coverage. The method proved to be an excellent alternative to microscopy for fast and reproducible quantification of microbial colonization on abiotic surfaces....

  17. Study of physiological properties of some probiotics in multiple cultures with mesophilic lactic acid bacteria by Flora Danica Ch. Hansen commercial starter

    OpenAIRE

    DANIELA PARASCHIV; AIDA VASILE; MADALINA CONSTANTIN; ALEXANDRU CIOBANU; GABRIELA BAHRIM

    2011-01-01

    The aim of this study was to establish the growth ability and stability of probiotic strains Lactobacillus acidophilus (commercial code La-5®), Lactobacillus casei ssp. paracasei (commercial code L. casei 431®) and Bifidobacterium bifidus (commercial code BB-12®) in multiple cultures with mesophilic lactic bacteria, Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. diacetylactis and Leuconostoc mesenteroides spp. cremoris, as Flora Danica Chr. Hansen co...

  18. Green synthesis of protein capped silver nanoparticles from phytopathogenic fungus Macrophomina phaseolina (Tassi) Goid with antimicrobial properties against multidrug-resistant bacteria

    OpenAIRE

    Chowdhury, Supriyo; Basu, Arpita; Kundu, Surekha

    2014-01-01

    In recent years, green synthesis of nanoparticles, i.e., synthesizing nanoparticles using biological sources like bacteria, algae, fungus, or plant extracts have attracted much attention due to its environment-friendly and economic aspects. The present study demonstrates an eco-friendly and low-cost method of biosynthesis of silver nanoparticles using cell-free filtrate of phytopathogenic fungus Macrophomina phaseolina. UV-visible spectrum showed a peak at 450 nm corresponding to the plasmon ...

  19. Frost-related dieback of willows. Comparison of epiphytically and endophytically isolated bacteria from different Salix clones, with emphasis on ice nucleation activity, pathogenic properties and seasonal variation

    Energy Technology Data Exchange (ETDEWEB)

    Cambours, M.A.; Nejad, P.; Ramstedt, M. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Plant Pathology and Biocontrol Unit; Granhall, U. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Department of Microbiology

    2005-01-01

    Swedish Salix plantation for biomass production have been suffering severe dieback during the past 10 years, possibly due to the combination of frost and bacterial disease. As opposed to summer and winter, spring and autumn are periods when epiphytic populations of ice nucleation active (INA) bacteria are generally high. The culturable bacterial floras from stems of diseased plant of four Salix viminalis clones were compared in spring and autumn. Both epiphytic and endophytic bacteria were isolated (i.e. from plant surface and from tissues beneath the bark, respectively), characterised and tested for ice nucleating activity and pathogenicity. Some strains were also identified with BIOLOG and 16S rRNA. Endophytically isolated communities were generally more stable than epiphytes, both in number of isolates and type of bacteria. More types were found in autumn than in spring the same year, although the total number of strains isolated was rather constant. In contrast, more strains (and a higher percentage of the total community) expressed ice nucleating activity in spring than in autumn. The overall number of pathogenic strains remained stable but their proportion among the community tested on plants increased. A close relationship was observed between the dieback rates in the field and the percentage of pathogenic strains found in the different clones. The dominating bacterial type isolated, Sphingomonas spp., also contained the highest percentage of ice nucleation active pathogenic strains. (author)

  20. Green synthesis of protein capped silver nanoparticles from phytopathogenic fungus Macrophomina phaseolina (Tassi) Goid with antimicrobial properties against multidrug-resistant bacteria

    Science.gov (United States)

    2014-01-01

    In recent years, green synthesis of nanoparticles, i.e., synthesizing nanoparticles using biological sources like bacteria, algae, fungus, or plant extracts have attracted much attention due to its environment-friendly and economic aspects. The present study demonstrates an eco-friendly and low-cost method of biosynthesis of silver nanoparticles using cell-free filtrate of phytopathogenic fungus Macrophomina phaseolina. UV-visible spectrum showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM) revealed the presence of spherical silver nanoparticles of the size range 5 to 40 nm, most of these being 16 to 20 nm in diameter. X-ray diffraction (XRD) spectrum of the nanoparticles exhibited 2θ values corresponding to silver nanoparticles. These nanoparticles were found to be naturally protein coated. SDS-PAGE analysis showed the presence of an 85-kDa protein band responsible for capping and stabilization of the silver nanoparticles. Antimicrobial activities of the silver nanoparticles against human as well as plant pathogenic multidrug-resistant bacteria were assayed. The particles showed inhibitory effect on the growth kinetics of human and plant bacteria. Furthermore, the genotoxic potential of the silver nanoparticles with increasing concentrations was evaluated by DNA fragmentation studies using plasmid DNA. PMID:25114655

  1. Green synthesis of protein capped silver nanoparticles from phytopathogenic fungus Macrophomina phaseolina (Tassi) Goid with antimicrobial properties against multidrug-resistant bacteria

    Science.gov (United States)

    Chowdhury, Supriyo; Basu, Arpita; Kundu, Surekha

    2014-07-01

    In recent years, green synthesis of nanoparticles, i.e., synthesizing nanoparticles using biological sources like bacteria, algae, fungus, or plant extracts have attracted much attention due to its environment-friendly and economic aspects. The present study demonstrates an eco-friendly and low-cost method of biosynthesis of silver nanoparticles using cell-free filtrate of phytopathogenic fungus Macrophomina phaseolina. UV-visible spectrum showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM) revealed the presence of spherical silver nanoparticles of the size range 5 to 40 nm, most of these being 16 to 20 nm in diameter. X-ray diffraction (XRD) spectrum of the nanoparticles exhibited 2 θ values corresponding to silver nanoparticles. These nanoparticles were found to be naturally protein coated. SDS-PAGE analysis showed the presence of an 85-kDa protein band responsible for capping and stabilization of the silver nanoparticles. Antimicrobial activities of the silver nanoparticles against human as well as plant pathogenic multidrug-resistant bacteria were assayed. The particles showed inhibitory effect on the growth kinetics of human and plant bacteria. Furthermore, the genotoxic potential of the silver nanoparticles with increasing concentrations was evaluated by DNA fragmentation studies using plasmid DNA.

  2. Facilitation of expression and purification of an antimicrobial peptide by fusion with baculoviral polyhedrin in Escherichia coli.

    Science.gov (United States)

    Wei, Quande; Kim, Young Soo; Seo, Jeong Hyun; Jang, Woong Sik; Lee, In Hee; Cha, Hyung Joon

    2005-09-01

    Several fusion strategies have been developed for the expression and purification of small antimicrobial peptides (AMPs) in recombinant bacterial expression systems. However, some of these efforts have been limited by product toxicity to host cells, product proteolysis, low expression levels, poor recovery yields, and sometimes an absence of posttranslational modifications required for biological activity. For the present work, we investigated the use of the baculoviral polyhedrin (Polh) protein as a novel fusion partner for the production of a model AMP (halocidin 18-amino-acid subunit; Hal18) in Escherichia coli. The useful solubility properties of Polh as a fusion partner facilitated the expression of the Polh-Hal18 fusion protein ( approximately 33.6 kDa) by forming insoluble inclusion bodies in E. coli which could easily be purified by inclusion body isolation and affinity purification using the fused hexahistidine tag. The recombinant Hal18 AMP ( approximately 2 kDa) could then be cleaved with hydroxylamine from the fusion protein and easily recovered by simple dialysis and centrifugation. This was facilitated by the fact that Polh was soluble during the alkaline cleavage reaction but became insoluble during dialysis at a neutral pH. Reverse-phase high-performance liquid chromatography was used to further purify the separated recombinant Hal18, giving a final yield of 30% with >90% purity. Importantly, recombinant and synthetic Hal18 peptides showed nearly identical antimicrobial activities against E. coli and Staphylococcus aureus, which were used as representative gram-negative and gram-positive bacteria, respectively. These results demonstrate that baculoviral Polh can provide an efficient and facile platform for the production or functional study of target AMPs.

  3. The purification process on scintillator material (SrI{sub 2}: Eu) by zone-refinement technique

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, Raja; Daniel, D. Joseph; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [SSN Research Centre, Sri SivaSubramaniya Nadar College of Engineering, Kalavakkam, Tamilnadu-603 110 (India)

    2015-06-24

    The thermal properties of Europium doped strontium iodide was analyzed through Thermogravimetric (TG) and differential thermal analyses (DTA). The melting point of europium doped strontium iodide is around 531°C. The hydrated and oxyhalide impurities were found before melting temperature. In order to remove these impurities we have done purification process by Zone-refinement technique. The effective output of purification of zone refining was also observed through the segregation of impurities.

  4. Travel of pollution, and purification en route, in sandy soils

    Science.gov (United States)

    Baars, J. K.

    1957-01-01

    The travel of pollution in sandy soils, and the extent to which purification takes place en route, are discussed, with special reference to the possible contamination of ground water—a problem which is of particular importance in the Netherlands, where the water-supply for many of the large towns is drawn from the water underneath the dunes. Specifically, two types of soil pollution are considered: (a) severe pollution of the surface layers with matter concentrated in a small volume of water (e.g., faecal matter from pit privies at camping-sites); and (b) moderate pollution of the surface layers with matter contained in large quantities of water (e.g., organic matter and bacteria in river water used for the artificial recharge of ground water). It is shown that in both these types of pollution the self-purification is sufficient to prevent contamination of the ground water, provided that the soil is very fine and—in the case of the first type—dry and well aerated, and provided that the ground-water level is not too high or the rate of infiltration too great. PMID:13472428

  5. Purification of novel peptide antibiotics from human milk.

    Science.gov (United States)

    Liepke, C; Zucht, H D; Forssmann, W G; Ständker, L

    2001-03-10

    A strategy was established for the identification of novel antimicrobial peptides from human milk. For the generation of bioactive peptides human milk was acidified and proteolyzed with pepsin simulating the digest in infants stomachs. Separation of proteins and resulting fragments was performed by means of reversed-phase chromatography detecting the antimicrobial activity of each fraction using a sensitive radial diffusion assay. In order to avoid the purification of the known abundant antimicrobial milk protein lysozyme, it was identified in HPLC fractions by its enzymatic activity and by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). On condition that lysozyme was not detectable and antibacterial activity of HPLC fractions was caused by a peptide, which was confirmed by proteolytic cleavage leading to a loss of activity, further purification was performed by consecutive chromatographic steps guided by the antibacterial assay. Using this strategy, an as yet unknown casein fragment exhibiting antimicrobial activity was purified in addition to antimicrobial lactoferrin fragments. The new antimicrobial peptide resembles a proteolytic fragment of human casein-K (residues 63-117) and inhibits the growth of gram-positive, gram-negative bacteria, and yeasts. Our results confirm that antimicrobially-active peptides are liberated from human milk proteins during proteolytic hydrolysis and may play an important role in the host defense system of the newborn.

  6. Simplified Method for Rapid Purification of Soluble Histones

    Directory of Open Access Journals (Sweden)

    Nives Ivić

    2016-06-01

    Full Text Available Functional and structural studies of histone-chaperone complexes, nucleosome modifications, their interactions with remodelers and regulatory proteins rely on obtaining recombinant histones from bacteria. In the present study, we show that co-expression of Xenopus laevis histone pairs leads to production of soluble H2AH2B heterodimer and (H3H42 heterotetramer. The soluble histone complexes are purified by simple chromatographic techniques. Obtained H2AH2B dimer and H3H4 tetramer are proficient in histone chaperone binding and histone octamer and nucleosome formation. Our optimized protocol enables rapid purification of multiple soluble histone variants with a remarkable high yield and simplifies histone octamer preparation. We expect that this simple approach will contribute to the histone chaperone and chromatin research. This work is licensed under a Creative Commons Attribution 4.0 International License.

  7. Purification

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    2017-01-01

    In Arequipa, Peru’s second largest city, engineers work hard to control water flows and provide different sectors with clean and sufficient water. In 2011, only 10 percent of the totality of water used daily by Arequipa’s then close to 1 million people—in households, tourism, industry, and mining......—was treated before it was returned to the river where it continues its flow downstream towards cultivated fields and, finally, into the Pacific Ocean. It takes specialized knowledge and manifold technologies to manage water and sustain life in Arequipa, and engineers are central actors for making water flow....... Examining the ecology of water management, this article asks to what extent we can talk of a way of knowing and enacting water that is particular to engineers. Through engineering practices, a technical domain emerges as separate from and superior to political and social domains. This production...

  8. ISOLATION AND IDENTIFICATION OF LACTIC ACID PRODUCING BACTERIA FROM CAMEL MILK

    OpenAIRE

    Toqeer Ahmad, Rashida Kanwal, Izhar Hussain Athar1, Najam Ayub

    2002-01-01

    Lactic acid bacteria (LAB) were isolated from camel milk by culturing the camel milk on specific media and pure culture was obtained by sub culturing. Purification of culture was confirmed by Gram's staining and identified by different bio-chemical tests. Camel milk contains lactic acid producing bacteria including Strpptococci such as S. cremoris and S. lactis and Lactobacilli such as L. acidophilus L. acidophilus grows more rapidly in camel milk than others as its growth is supported by cam...

  9. Reverse osmosis water purification system

    Science.gov (United States)

    Ahlstrom, H. G.; Hames, P. S.; Menninger, F. J.

    1986-01-01

    A reverse osmosis water purification system, which uses a programmable controller (PC) as the control system, was designed and built to maintain the cleanliness and level of water for various systems of a 64-m antenna. The installation operates with other equipment of the antenna at the Goldstone Deep Space Communication Complex. The reverse osmosis system was designed to be fully automatic; with the PC, many complex sequential and timed logic networks were easily implemented and are modified. The PC monitors water levels, pressures, flows, control panel requests, and set points on analog meters; with this information various processes are initiated, monitored, modified, halted, or eliminated as required by the equipment being supplied pure water.

  10. Purification Protocols for Extracellular Vesicles.

    Science.gov (United States)

    Lane, Rebecca E; Korbie, Darren; Trau, Matt; Hill, Michelle M

    2017-01-01

    This chapter provides a description of some of the standard methods used for the isolation of extracellular vesicles (EVs) from a variety of biological fluids, including cell culture media, urine, plasma and serum. The methods presented include ultracentrifugation, ultrafiltration, proprietary polymer-based reagents, size exclusion chromatography, density gradient separation, and immunoaffinity capture. Ultracentrifugation methods use high speed centrifugation to pellet vesicles, whilst polymer-based reagents are added to the sample to facilitate vesicle precipitation using lower speeds. Ultrafiltration involves the concentration of vesicles from a large volume of biological fluid using a centrifugal filter unit. Size exclusion chromatography and density gradient separation are both designed to allow the separation of vesicles from other nonvesicular debris. Immunoaffinity capture methods use antibody-coated beads to selectively isolate vesicles displaying a surface marker of interest. Ultimately, the choice of purification method for an individual experiment is influenced by time, cost, and equipment considerations, as well as the sample requirements for any downstream analyses.

  11. Preparation, purification and characterization of 125I-glucagon used for radioimmunoassay

    International Nuclear Information System (INIS)

    Ruehlmann, C.; Poege, A.; Stollmaier, P.; Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1988-01-01

    A method for the radioactive labelling of glucagon with Na 125 I with the help of chloramine T for the use in radioimmunoassay is described. The purification of 125 I-glucagon with polyacrylamide gel electrophoresis, the characterization of the tracer, its stability and the immunological properties are described. (author)

  12. The effectiveness of novel bacteriocin derived from Escherichia coli colonized in the fermented pineapple Ananas comosus (L. Merr. against pathogenic bacteria isolated from aquaculture sites

    Directory of Open Access Journals (Sweden)

    S. W. Lee

    2014-11-01

    Full Text Available Aim: The aim was to evaluate antimicrobial property of bacteriocin isolated from Escherichia coli against pathogenic bacteria from aquaculture sites. Materials and Methods: E. coli was isolated from fermented pineapple Ananas comosus using eosin methylene blue agar. The antimicrobial activity of the isolated E. coli was screened using hole-plate diffusion method. The bacterial strain that showed the widest inhibition zone was selected and grown in tryptic soy broth, followed by partial purification of bacteriocin by using ammonium sulphate. Bacteriocin derived from the E. coli was subjected to the antimicrobial test against 55 bacteria strains namely Aeromonas hydrophila (n=10, Citrobacter freundii (n=5, Edwardsiella tarda (n=10, Flavobacterium spp. (n=10, Pseudomonas spp. (n=10, Vibrio parahaemolyticus (n=5 and Vibrio alginolyticus (n=5 by using twofold broth microdilution method to determine minimum inhibitory concentration (MIC values of the bacteriocin against the tested bacteria. Results: The results of the present study showed that the MIC values of the partially purified bacteriocin against present pathogenic bacteria isolates ranged from 7.81 to 31.25 ppm whereas the MIC values of kanamycin (positive control ranged from 15.63 to 125 ppm. Conclusion: The results of the present study showed the bacteriocin derived from E. coli can control all the present bacterial isolates indicating the huge potential of the bacteriocin as a new antimicrobial agent for aquaculture uses.

  13. Dormant bacteria within Staphylococcus epidermidis biofilms have low inflammatory properties and maintain tolerance to vancomycin and penicillin after entering planktonic growth.

    Science.gov (United States)

    Cerca, Filipe; França, Angela; Pérez-Cabezas, Begoña; Carvalhais, Virgínia; Ribeiro, Adília; Azeredo, Joana; Pier, Gerald; Cerca, Nuno; Vilanova, Manuel

    2014-10-01

    Staphylococcus epidermidis is the most commonly isolated aetiological agent of nosocomial infections, mainly due to its ability to establish biofilms on indwelling medical devices. Detachment of bacteria from S. epidermidis biofilms and subsequent growth in the planktonic form is a hallmark of the pathogenesis of these infections leading to dissemination. Here we showed that S. epidermidis cells collected from biofilms cultured in conditions that promote cell viability present marked changes in their physiological status upon initiating a planktonic mode of growth. When compared to cells growing in biofilms, they displayed an increased SYBR green I staining intensity, increased transcription of the rpiA gene, decreased transcription of the icaA gene, as well as higher susceptibility to vancomycin and penicillin. When bacteria collected from biofilms with high proportions of dormant cells were subsequently cultured in the planktonic mode, a large proportion of cells maintained a low SYBR green I staining intensity and increased resistance to vancomycin and penicillin, a profile typical of dormant cells. This phenotype further associated with a decreased ability of these biofilm-derived cells to induce the production of pro-inflammatory cytokines by bone marrow-derived dendritic cells in vitro. These results demonstrated that cells detached from the biofilm maintain a dormant cell-like phenotype, having a low pro-inflammatory effect and decreased susceptibility to antibiotics, suggesting these cells may contribute to the recalcitrant nature of biofilm infections. © 2014 The Authors.

  14. The potent antimicrobial properties of cell penetrating peptide-conjugated silver nanoparticles with excellent selectivity for Gram-positive bacteria over erythrocytes

    Science.gov (United States)

    Liu, Lihong; Yang, Jun; Xie, Jianping; Luo, Zhentao; Jiang, Jiang; Yang, Yi Yan; Liu, Shaomin

    2013-04-01

    Silver nanoparticles are of great interest for use as antimicrobial agents. Studies aimed at producing potent nano-silver biocides have focused on manipulation of particle size, shape, composition and surface charge. Here, we report the cell penetrating peptide catalyzed formation of antimicrobial silver nanoparticles in N,N-dimethylformamide. The novel nano-composite demonstrated a distinctly enhanced biocidal effect toward bacteria (Gram-positive Bacillus subtilis, Gram-negative Escherichia coli) and pathogenic yeast (Candida albicans), as compared to triangular and extremely small silver nanoparticles. In addition, a satisfactory biocompatibility was verified by a haemolysis test. Our results provide a paradigm in developing strategies that can maximize the silver nanoparticle application potentials while minimizing the toxic effects.Silver nanoparticles are of great interest for use as antimicrobial agents. Studies aimed at producing potent nano-silver biocides have focused on manipulation of particle size, shape, composition and surface charge. Here, we report the cell penetrating peptide catalyzed formation of antimicrobial silver nanoparticles in N,N-dimethylformamide. The novel nano-composite demonstrated a distinctly enhanced biocidal effect toward bacteria (Gram-positive Bacillus subtilis, Gram-negative Escherichia coli) and pathogenic yeast (Candida albicans), as compared to triangular and extremely small silver nanoparticles. In addition, a satisfactory biocompatibility was verified by a haemolysis test. Our results provide a paradigm in developing strategies that can maximize the silver nanoparticle application potentials while minimizing the toxic effects. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr34254a

  15. SOLAIR disinfection of coliform bacteria in hand-drawn drinking water

    African Journals Online (AJOL)

    specifically UV-A and UV-B radiation) and oxygen (from atmospheric air) to damage, inactivate and / or kill the coliform bacteria found in contaminated water. It is a natural process (virtually self-purification) with no need to add any potentially hazardous ...

  16. Optimized Expression and Purification for High-Activity Preparations of Algal [FeFe]-Hydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Yacoby, I.; Tegler, L. T.; Pochekailov, S.; Zhang, S.; King, P. W.

    2012-04-01

    Recombinant expression and purification of metallo-enzymes, including hydrogenases, at high-yields is challenging due to complex, and enzyme specific, post-translational maturation processes. Low fidelities of maturation result in preparations containing a significant fraction of inactive, apo-protein that are not suitable for biophysical or crystallographic studies. We describe the construction, overexpression and high-yield purification of a fusion protein consisting of the algal [2Fe2S]-ferredoxin PetF (Fd) and [FeFe]-hydrogenase HydA1. The maturation of Fd-HydA1 was optimized through improvements in culture conditions and media components used for expression. We also demonstrated that fusion of Fd to the N-terminus of HydA1, in comparison to the C-terminus, led to increased expression levels that were 4-fold higher. Together, these improvements led to enhanced HydA1 activity and improved yield after purification. The strong binding-affinity of Fd for DEAE allowed for two-step purification by ion exchange and StrepTactin affinity chromatography. In addition, the incorporation of a TEV protease site in the Fd-HydA1 linker allowed for the proteolytic removal of Fd after DEAE step, and purification of HydA1 alone by StrepTactin. In combination, this process resulted in HydA1 purification yields of 5 mg L{sup -1} of culture from E. coli with specific activities of 1000 U (U = 1 {micro}mol hydrogen evolved mg{sup -1} min{sup -1}). The [FeFe]-hydrogenases are highly efficient enzymes and their catalytic sites provide model structures for synthetic efforts to develop robust hydrogen activation catalysts. In order to characterize their structure-function properties in greater detail, and to use hydrogenases for biotechnological applications, reliable methods for rapid, high-yield expression and purification are required.

  17. Chemical communication in bacteria

    Science.gov (United States)

    Suravajhala, Srinivasa Sandeep; Saini, Deepak; Nott, Prabhu

    Luminescence in Vibrio fischeri is a model for quorum-sensing-gene-regulation in bacteria. We study luminescence response of V. fischeri to both internal and external cues at the single cell and population level. Experiments with ES114, a wild-type strain, and ainS mutant show that luminescence induction in cultures is not always proportional to cell-density and there is always a basal level of luminescence. At any given concentration of the exogenously added signals, C6-HSL and C8-HSL, luminescence per cell reaches a maximum during the exponential phase and decreases thereafter. We hypothesize that (1) C6-HSL production and LuxR activity are not proportional to cell-density, and (2) there is a shift in equilibrium from C6-HSL to C8-HSL during the later stages of growth of the culture. RT-PCR analysis of luxI and luxR shows that the expression of these genes is maximum corresponding to the highest level of luminescence. The shift in equilibrium is shown by studying competitive binding of C6-HSL and C8-HSL to LuxR. We argue that luminescence is a unicellular behaviour, and an intensive property like per cell luminescence is more important than gross luminescence of the population in understanding response of bacteria to chemical signalling. Funding from the Department of Science and Technology, India is acknowledged.

  18. Purification, crystallization and preliminary X-ray structure analysis of the laccase from Ganoderma lucidum

    International Nuclear Information System (INIS)

    Lyashenko, Andrey V.; Belova, Oksana; Gabdulkhakov, Azat G.; Lashkov, Alexander A.; Lisov, Alexandr V.; Leontievsky, Alexey A.; Mikhailov, Al’bert M.

    2011-01-01

    The purification, crystallization and preliminary X-ray structure analysis of the laccase from G. lucidum are reported. The ligninolytic enzymes of the basidiomycetes play a key role in the global carbon cycle. A characteristic property of these enzymes is their broad substrate specificity, which has led to their use in various biotechnologies, thus stimulating research into the three-dimensional structures of ligninolytic enzymes. This paper presents the purification, crystallization and preliminary X-ray analysis of the laccase from the ligninolytic basidiomycete Ganoderma lucidum

  19. Purification of beta-acetylglucosaminase and beta-galactosidase from ram testis.

    Science.gov (United States)

    Caygill, J C; Roston, C P; Jevons, F R

    1966-02-01

    1. The presence of beta-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of beta-acetylglucosaminase (EC 3.2.1.30) and of beta-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the beta-acetylglucosaminase 35 times and for the beta-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated.

  20. Purification and characterization of thermostable glucoamylase from ...

    African Journals Online (AJOL)

    Thermostable glucoamylase from Rhizopus oligosporus SK5 mutant was purified in a 3-step purification using Imarsil, activated charcoal and Sephadex-G-100 to achieve a 40-fold purification. The enzyme was optimally active at pH 5.0 and temperature of 80 °C. It exhibited a half-life of 60 minutes at 70 °C. Its stability was ...

  1. Study of physiological properties of some probiotics in multiple cultures with mesophilic lactic acid bacteria by Flora Danica Ch. Hansen commercial starter

    Directory of Open Access Journals (Sweden)

    DANIELA PARASCHIV

    2011-12-01

    Full Text Available The aim of this study was to establish the growth ability and stability of probiotic strains Lactobacillus acidophilus (commercial code La-5®, Lactobacillus casei ssp. paracasei (commercial code L. casei 431® and Bifidobacterium bifidus (commercial code BB-12® in multiple cultures with mesophilic lactic bacteria, Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. diacetylactis and Leuconostoc mesenteroides spp. cremoris, as Flora Danica Chr. Hansen commercial starters. Under the controlled fermentative conditions described below, a good starter combination, for the high rate of cells multiplication and for the good viability during storage, was identified in the mixture of L. casei 431®, BB-12® and Flora Danica, in ratio of 1:1:1 (9 log CFU/mL for each starter culture.

  2. Determination of Ammonia Oxidizing Bacteria and Nitrate Oxidizing Bacteria in Wastewater and Bioreactors

    Science.gov (United States)

    Francis, Somilez Asya

    2014-01-01

    The process of water purification has many different physical, chemical, and biological processes. One part of the biological process is the task of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Both play critical roles in the treatment of wastewater by oxidizing toxic compounds. The broad term is nitrification, a naturally occurring process that is carried out by AOB and NOB by using oxidation to convert ammonia to nitrite and nitrite to nitrate. To monitor this biological activity, bacterial staining was performed on wastewater contained in inoculum tanks and biofilm samples from bioreactors. Using microscopy and qPCR, the purpose of this experiment was to determine if the population of AOB and NOB in wastewater and membrane bioreactors changed depending on temperature and hibernation conditions to determine the optimal parameters for AOB/NOB culture to effectively clean wastewater.

  3. Purification of antibody against Ara h 2 by a homemade immunoaffinity chromatography column.

    Science.gov (United States)

    Wu, Zhihua; Li, Kun; Zhan, Shaode; Tong, Ping; Li, Xin; Yang, Anshu; Chen, Hongbing

    2017-09-14

    Antibodies are used extensively in numerous applications both in vivo and in vitro. To purify anti-Ara h 2 polyclonal antibody, a homemade immunoaffinity chromatography (IAC) column method was established. The properties of homemade column were compared with those of the mAb affinity protein G (MPG) agarose high flow, a commercially available column successfully used in capturing polyclonal antibodies. During antibody purification from rabbits' antiserum against Ara h 2, the column capacity, recovery, and purification factor were characterized for IAC and MPG. The homemade IAC could separate the corresponding antibody with higher specificity and lower cost but with lower recovery and column capacity than those of MPG. Thus, the homemade IAC is a specific, inexpensive, and suitable method that can be used for various laboratory purifications.

  4. Human body may produce bacteria.

    Science.gov (United States)

    Salerian, Alen J

    2017-06-01

    "Human body may produce bacteria" proposes that human body may produce bacteria and represent an independent source of infections contrary to the current paradigm of infectious disorders proposed by Louis Pasteur in 1880. The following observations are consistent with this hypothesis: A. Bidirectional transformations of both living and nonliving things have been commonly observed in nature. B. Complex multicellular organisms harbor the necessary properties to produce bacteria (water, nitrogen and oxygen). C. Physical laws suggest any previously observed phenomenon or action will occur again (life began on earth; a non living thing). D. Animal muscle cells may generate energy (fermentation). E. Sterilized food products (i.e. boiled eggs), may produce bacteria and fungus under special conditions and without any exposure to foreign living cells. "Human body may produce bacteria" may challenge the current medical paradigm that views human infectious disorders as the exclusive causative byproducts of invading foreign cells. It may also introduce new avenues to treat infectious disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Utilization of internal purification rejects; Sisaeisen puhdistuksen rejektikonsentraattien kelvollistaminen - KLT 02

    Energy Technology Data Exchange (ETDEWEB)

    Manner, H.; Nissen, M.

    1998-12-31

    This was a preliminary study which is part of a larger programme. The aim of the programme is to determine the properties and process ability of the concentrates which come from the internal purification of waters from the papermaking process. It is very important to know the properties and process ability of these purification concentrates in order to find the best methods of separating, reprocessing and utilizing them. The objective of this preliminary study was to ascertain the basic properties of these internal purification concentrates. It was also of interest to analyse the properties of papermaking waters and the state of internal purification today in paper mills. The state of papermaking waters and their internal purification were clarified by a literature review and by analyses of different types of waters. It was found that in mechanical pulping organic dissolved and colloidal substances were present in the water. Also there was a lot of dissolved and colloidal substances in waters from machines producing wood-containing paper grades. The salt content and chemical oxygen demand are critical values concerning the reuse of circulation waters. In mechanical pulping the convection of dissolved and colloidal substances to the paper machine can be reduced by the washing stage. Thus, the amount of dissolved and colloidal substances in the paper machine circulation waters can be reduced. In a paper machine, a disk filter removes fibers and fines from the circulation waters, but dissolved and colloidal substances are not removed. Also the properties of different kind of membrane filtration concentrates were analyzed. The total residue of membrane concentrates is low. For example, they can not be burned purely. The chemical oxygen demand of membrane concentrates is high. The most important subjects for further investigation are the improvement of fractionation and condensability. Furthermore procedures must be found to lower the chemical oxygen demand. One

  6. Towards electrochemical purification of chemically reduced graphene oxide from redox accessible impurities.

    Science.gov (United States)

    Tan, Shu Min; Ambrosi, Adriano; Khezri, Bahareh; Webster, Richard D; Pumera, Martin

    2014-04-21

    The electrochemical properties of graphene are highly sensitive to residual metallic impurities that persist despite various purification efforts. To accurately evaluate the electrochemical performance of graphene, highly purified materials free of metallic impurities are required. In this study, the partial purification of chemically reduced graphene oxides prepared via Hummers (CRGO-HU) and Staudenmaier (CRGO-ST) oxidation methods was performed through cyclic voltammetric (CV) scans executed in nitric acid, followed by CV measurements of cumene hydroperoxide (CHP). The purification of graphene was monitored by the changes in the peak current and potential of CHP which is sensitive to iron impurities. The CRGOs were characterised by inductively coupled plasma-mass spectrometry (ICP-MS), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and CV. The micrographs revealed CRGOs of similar morphologies, but with greater defects in CRGO-HU. The dependencies of CHP peak current and peak potential on the number of purification cycles exhibit greater efficiency of removing iron impurities from CRGO-HU than CRGO-ST. This can be attributed to the oxidative method that is used in CRGO-HU production, which exposes more defect sites for iron impurities to reside in. This facile electrochemical purification of graphenes can be utilised as a routine preparation and cleaning method of graphene before electrochemical measurements for analytes that show exceptional sensitivity towards electrocatalytic metallic impurities in sp(2) nanocarbon materials.

  7. PURIFICATION AND CHARACTERIZATION OF POLY-HYDROXYBUTYRATE (PHB IN CUPRIAVIDUS NECATOR

    Directory of Open Access Journals (Sweden)

    Sergio Leon De Rooy

    2010-06-01

    Full Text Available Purification and characterization of biodegradable plastic namely Polyhydroxybutyrate (PHB in Cupriavidus necator have been carried out. C. necator was grown on a Ramsay medium with fixed substrate conditions and optimized for time. Stepwise purification of PHB was carried out, by using hydrogen peroxide and chloroform. The effect of temperature, time, and hydrogen peroxide concentration on the purification were also evaluated. The extracted PHB was studied with XRD, FTIR and 1H-NMR and 13C-NMR to determine its structure and purity. Yield and crystallinity were also studied with HPLC and XRD, respectively. The results of the research showed that higher concentrations of hydrogen peroxide gave better yields, whereas higher temperatures and longer lysis times led to different results. Higher crystallinity was observed when purification temperatures were elevated, but higher hydrogen peroxide concentration and longer extraction time gave varying crystallinity. The highest yield ca 66.10 % DCW was reached by purification using H2O2 20 %, at 100 oC for 2 h. The results of   TGA analysis indicated that the purity of the PHB obtained was about 75 % and by using DSC, it was found that the PHB showed good thermal properties.   Keywords:  PHB, recovery, hydrogen peroxide, characterization

  8. Purification processes for coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, D.K.; Primack, H.S.

    1977-01-01

    It is apparent from the discussion that many routes can be taken to achieve acid-gas removal and sulfur recovery from coal gas. The selection of the optimum purification system is a major task. The type of coal, type of gasifier and the upstream processing all strongly influence the selection. Several generalizations can be made: (1) The cost of the purification sections of a high-Btu gas plant is significant--perhaps 10 to 30% of the capital cost of the coal conversion facility. (2) The cost of purifying gas produced from high-sulfur coal feed is more expensive than the cost for purifying gas produced from low-sulfur coal. (3) The choice of an acid-gas removal system will often be a function of system pressure. The economical choice will usually be: (a) amine-based systems at atmospheric pressure; (b) hot-carbonate systems at moderate pressure or (c) physical-solvent systems at higher pressure. (4) For a high-Btu, high-sulfur case: (a) A selective acid-gas removal system with a Claus plant is probably more economical than a non-selective acid-gas system with liquid oxidation of the H/sub 2/S in the regenerator off-gas. (b) Even moderately selective systems can produce an H/sub 2/S-rich gas suitable for a Claus plant. The CO/sub 2/-rich gas may or may not require further sulfur removal, depending on the selectivity. (5) For a high-Btu, low-sulfur case: (a) The hot carbonate and tertiary amine systems may not be sufficiently selective to produce a gas suitable for feed to a Claus process while a physical solvent system may be. Therefore, the physical solvent system may be expected to be more economical. (b) The regenerated gas from the bulk CO/sub 2/ removal system following a selective physical solvent system may require further sulfur removal, depending upon the sulfur level in the initial feedstock and the selectivity of the system selected.

  9. Study of Antibacterial Efficacy of Hybrid Chitosan-Silver Nanoparticles for Prevention of Specific Biofilm and Water Purification

    Directory of Open Access Journals (Sweden)

    Somnath Ghosh

    2011-01-01

    Full Text Available Antibacterial efficacy of silver nanoparticles (Ag NPs deposited alternatively layer by layer (LBL on chitosan polymer in the form of a thin film over a quartz plate and stainless steel strip has been studied. An eight-bilayer chitosan/silver (Cs/Ag8 hybrid was prepared having a known concentration of silver. Techniques such as UV-visible spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES, and atomic force microscopy (AFM were carried out to understand and elucidate the physical nature of the film. Gram-negative bacteria, Escherichia coli (E. coli, were used as a test sample in saline solution for antibacterial studies. The growth inhibition at different intervals of contact time and, more importantly, the antibacterial properties of the hybrid film on repeated cycling in saline solution have been demonstrated. AFM studies are carried out for the first time on the microbe to know the morphological changes affected by the hybrid film. The hybrid films on aging (3 months are found to be as bioactive as before. Cytotoxicity experiments indicated good biocompatibility. The hybrid can be a promising bioactive material for the prevention of biofilms specific to E. coli and in purification of water for safe drinking.

  10. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  11. Bio-inspired control of material properties in civil engineering : Current concept for corrsoion protection via the application of bacteria and bio-polymers

    NARCIS (Netherlands)

    Koleva, D.A.; Jonkers, H.M.; van Breugel, K.

    2013-01-01

    The improvement of material properties of cement-based materials e.g. reduced permeability, porosity, uniform distribution of hydration products, etc. is of a significant importance and related to durability and sustainability of concrete and reinforced concrete structures. With this respect, a

  12. Dialysis membranes for blood purification.

    Science.gov (United States)

    Sakai, K

    2000-01-01

    All of the artificial membranes in industrial use, such as a reverse-osmosis membrane, dialysis membrane, ultrafiltration membrane, microfiltration membrane and gas separation membrane, also have therapeutic applications. The most commonly used artificial organ is the artificial kidney, a machine that performs treatment known as hemodialysis. This process cleanses the body of a patient with renal failure by dialysis and filtration, simple physicochemical processes. Hemodialysis membranes are used to remove accumulated uremic toxins, excess ions and water from the patient via the dialysate, and to supply (deficit) insufficient ions from the dialysate. Dialysis membranes used clinically in the treatment of patients with renal failure account for by far the largest volume of membranes used worldwide; more than 70 million square meters are used a year. Almost all dialyzers now in use are of the hollow-fiber type. A hollow-fiber dialyzer contains a bundle of approximately 10000 hollow fibers, each with an inner diameter of about 200 microm when wet. The membrane thickness is about 20-45 microm, and the length is 160-250 mm. The walls of the hollow fibers function as the dialysis membrane. Various materials, including cellulose-based materials and synthetic polymers, are used for dialysis membranes. This paper reviews blood purification, hemodialysis and dialysis membranes.

  13. Antimicrobial properties of lactic acid bacteria and yeast-LAB cultures isolated from traditional fermented milk against pathogenic Escherichia coli and Salmonella enteritidis strains.

    Science.gov (United States)

    Mufandaedza, J; Viljoen, B C; Feresu, S B; Gadaga, T H

    2006-04-15

    The survival and growth of Escherichia coli 3339 and Salmonella enteritidis 949575 isolated from human clinical samples, in milk fermented with lactic acid bacteria (LAB) and yeast strains previously isolated from Zimbabwean naturally fermented milk (NFM) was studied. The LAB starter cultures used were Lactococcus lactis subsp. lactis biovar. diacetylactis C1 alone (C1) or in combination with Candida kefyr 23 (C1/23), L. lactis subsp. lactis Lc261 alone (LC261) or in combination with C. kefyr 23 (Lc261/23). The growth of the same pathogens in milk fermented with a commercial DL culture (CH-N 22) and spontaneously fermented raw milk was also monitored. The C1 and C1/23 cultures significantly (Pfermentation, both E. coli 3339 and S. enteritidis 949575 counts were significantly (Pmilk. However, in naturally fermented milk and the DL cultured milk, both E. coli 3339 and S. enteritidis 949575 grew and reached high populations of about 9 and 8.8 log cfu ml(-1), respectively, after 18 h. When E. coli 3339 was inoculated into previously fermented milk, the viable counts were significantly (Pfermented NFM and the commercial DL- (CH-N 22) cultured milk. The C1 strain, therefore, offered the best protection against the pathogens. Its inhibitory effect was mainly related to fast acid production.

  14. Flexible thin-layer plasma inactivation of bacteria and mold survival in beef jerky packaging and its effects on the meat's physicochemical properties.

    Science.gov (United States)

    Yong, Hae In; Lee, Haelim; Park, Sanghoo; Park, Jooyoung; Choe, Wonho; Jung, Samooel; Jo, Cheorun

    2017-01-01

    The aims of the present study were to examine the use of a flexible thin-layer plasma system in inactivating bacteria and mold on beef jerky in a commercial package and to evaluate the physicochemical changes of the jerky. After plasma treatment for 10min, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Aspergillus flavus populations on the beef jerky were reduced by approximately 2 to 3Log CFU/g. No significant changes in metmyoglobin content, shear force, and myofibrillar fragmentation index were found in the plasma-treated beef jerky. On the other hand, the peroxide content and L ⁎ value were decreased whereas the a ⁎ and ΔE value were increased in the plasma-treated sample. Sensory evaluation indicated negative effects of plasma treatment on flavor, off-odor, and overall acceptability of the beef jerky. In conclusion, the flexible thin-layer plasma system could be employed as a means for decontamination of beef jerky, with slight changes to the physicochemical quality of the product. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Antifungal Activity of Selected Lactic Acid Bacteria and Propionic Acid Bacteria against Dairy-Associated Spoilage Fungi

    DEFF Research Database (Denmark)

    Aunsbjerg, Stina Dissing

    Bacterial cultures of lactic and propionic acid bacteria are widely used in fermented products including dairy products. Spoilage fungi may constitute a quality and safety issue in these products. The antifungal properties of some lactic and propionic acid bacteria make them potential candidates...... diacetyl and lactic acid, 6 antifungal hydroxy acids were identified. Of these, 3 have previously been reported from antifungal lactic acid bacteria, whereas the other 3 hydroxy acids have not previously been reported produced by antifungal lactic acid bacteria....

  16. Photocatalytic materials and technologies for air purification.

    Science.gov (United States)

    Ren, Hangjuan; Koshy, Pramod; Chen, Wen-Fan; Qi, Shaohua; Sorrell, Charles Christopher

    2017-03-05

    Since there is increasing concern for the impact of air quality on human health, the present work surveys the materials and technologies for air purification using photocatalytic materials. The coverage includes (1) current photocatalytic materials for the decomposition of chemical contaminants and disinfection of pathogens present in air and (2) photocatalytic air purification systems that are used currently and under development. The present work focuses on five main themes. First, the mechanisms of photodegradation and photodisinfection are explained. Second, system designs for photocatalytic air purification are surveyed. Third, the photocatalytic materials used for air purification and their characteristics are considered, including both conventional and more recently developed photocatalysts. Fourth, the methods used to fabricate these materials are discussed. Fifth, the most significant coverage is devoted to materials design strategies aimed at improving the performance of photocatalysts for air purification. The review concludes with a brief consideration of promising future directions for materials research in photocatalysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Ionic behavior of treated water at a water purification plant

    OpenAIRE

    Yanagida, Kazumi; Kawahigashi, Tatsuo

    2012-01-01

    [Abstract] Water at each processing stage in a water purification plant was extracted and analyzed to investigate changes of water quality. Investigations of water at each processing stage at the water purification plant are discussed herein.

  18. Simplified riboprobe purification using translucent straws as gel tubes.

    Science.gov (United States)

    Kol, S; Ben-Shlomo, I; Adashi, E Y; Rohan, R M

    1996-01-01

    Gel purification of radioactive riboprobes enhances the quality of the ribonuclease protection assay. A simple and effective method for riboprobe purification is described. The method uses acrylamide gels in plastic tubes to achieve electrophoretic separation of the RNA polymerase products.

  19. Protein purification protocols [Methods in molecular biology, v. 59

    National Research Council Canada - National Science Library

    Doonan, Shawn

    1996-01-01

    ... both chemical and molecular methods, and how to dry and store the purified protein. Protein Purification Protocols provides all that is needed to design and carry out a successful purification program...

  20. Exopolysaccharides produced by lactic acid bacteria

    NARCIS (Netherlands)

    Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe

    2016-01-01

    A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and

  1. Influence of pore former on porosity and mechanical properties of Ce0.9Gd0.1O1.95 electrolytes for flue gas purification

    DEFF Research Database (Denmark)

    Charlas, Benoit; Schmidt, Cristine Grings; Frandsen, Henrik Lund

    2016-01-01

    excitation technique (Young modulus) and flexural strength measurements, to investigate the role of the different pore formers on the properties of the compounds. The compared techniques used to evaluate porosity give consistent results. The ratio between open and total porosities, evaluated from mercury...

  2. Purification and characterization of angiotensin-1 converting enzyme

    African Journals Online (AJOL)

    user

    2013-04-10

    Apr 10, 2013 ... al., 1999), meat (Jang and Lee, 2005) and marine resources (Je et al., ... species that have been blooming on the offshore areas of. Korea, China and ..... Lim et al. 1893. Table 1. Purification yield and ACE-inhibitory activity of each step. Fraction. Purification step. Purification yield (%). IC50 (μg/ml). W/H.

  3. Laboratory technology for hydrogen purification in liquefying installations

    International Nuclear Information System (INIS)

    Avram, I.; David, E.; Dordea, M.; Peculea, M.; Pop, F.; Stanciu, V.; Varzaru, O.; Panu, E.; Curuia, M.; Fron, P.; Balint, I.; Culcer, M.; Roman, T.; Smeureanu, N.

    1995-01-01

    This paper presents the development of a laboratory installation for purification of the hydrogen to be liquefied. The purification is achieved by the procedure of physical adsorption at low temperature. This procedure implies the use of materials with extensive active surfaces such as activated carbon, molecular sieves and silica gels. The main stages of the purification process are described

  4. Tandem Affinity Purification Approach Coupled to Mass Spectrometry to Identify Post-translational Modifications of Histones Associated with Chromatin-Binding Proteins.

    Science.gov (United States)

    Beyer, Sophie; Robin, Philippe; Ait-Si-Ali, Slimane

    2017-01-01

    Protein purification by tandem affinity purification (TAP)-tag coupled to mass spectrometry analysis is usually used to reveal protein complex composition. Here we describe a TAP-tag purification of chromatin-bound proteins along with associated nucleosomes, which allow exhaustive identification of protein partners. Moreover, this method allows exhaustive identification of the post-translational modifications (PTMs) of the associated histones. Thus, in addition to partner characterization, this approach reveals the associated epigenetic landscape that can shed light on the function and properties of the studied chromatin-bound protein.

  5. Purification non-aqueous solution of quantum dots CdSe- CdS-ZnS from excess organic substance-stabilizer by use PE- HD membrane

    International Nuclear Information System (INIS)

    Kosolapova, K; Al-Alwani, A; Gorbachev, I; Glukhovskoy, E

    2015-01-01

    Recently, a new simple method for the purification of CdSe-CdS-ZnS quantum dots by using membrane filtration, the filtration process, successfully separated the oleic acid from quantum dots through membranes purification after synthesis; purification of quantum dots is a very significant part of post synthetical treatment that determines the properties of the material. We explore the possibilities of the Langmuir-Blodgett technique to make such layers, using quantum dots as a model system. The Langmuir monolayer of quantum dots were then investigated the surface pressure-area isotherm. From isotherm, we found the surface pressure monolayer changed with time. (paper)

  6. Comparison of the properties of cellulose nanocrystals and cellulose nanofibrils isolated from bacteria, tunicate, and wood processed using acid, enzymatic, mechanical, and oxidative methods.

    Science.gov (United States)

    Sacui, Iulia A; Nieuwendaal, Ryan C; Burnett, Daniel J; Stranick, Stephan J; Jorfi, Mehdi; Weder, Christoph; Foster, E Johan; Olsson, Richard T; Gilman, Jeffery W

    2014-05-14

    This work describes the measurement and comparison of several important properties of native cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs), such as crystallinity, morphology, aspect ratio, and surface chemistry. Measurement of the fundamental properties of seven different CNCs/CNFs, from raw material sources (bacterial, tunicate, and wood) using typical hydrolysis conditions (acid, enzymatic, mechanical, and 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-mediated oxidation), was accomplished using a variety of measurement methods. Atomic force microscopy (AFM), transmission electron microscopy (TEM), and 13C cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy were used to conclude that CNCs, which are rodlike in appearance, have a higher crystallinity than CNFs, which are fibrillar in appearance. CNC aspect ratio distributions were measured and ranged from 148±147 for tunicate-CNCs to 23±12 for wood-CNCs. Hydrophobic interactions, measured using inverse gas chromatography (IGC), were found to be an important contribution to the total surface energy of both types of cellulose. In all cases, a trace amount of naturally occurring fluorescent compounds was observed after hydrolysis. Confocal and Raman microscopy were used to confirm that the fluorescent species were unique for each cellulose source, and demonstrated that such methods can be useful for monitoring purity during CNC/CNF processing. This study reveals the broad, tunable, multidimensional material space in which CNCs and CNFs exist.

  7. Method of water purification from chromium (VI with the presence of microorganisms

    Directory of Open Access Journals (Sweden)

    Олена Георгіївна Горшкова

    2015-09-01

    Full Text Available The high efficiency of water purification from chromium (VI by the polyfunctional bacterial suspension consisted of the association of non-pathogenic bacteria strains of the genus Pseudomonas: P. fluorescens ONU328, P. maltophilia ONU329, P. cepacia ONU327 in a volume ratio of 1:1:1 is experimentally confirmed. The method allows in the presence of hydrogen peroxide and calcium chloride to purify contaminated water from chromium (VI with concentration up to 70 mg/dm3 to values of concentration smaller than the maximum allowable concentration

  8. Bismuth Oxysulfide and Its Polymer Nanocomposites for Efficient Purification

    Directory of Open Access Journals (Sweden)

    Yidong Luo

    2018-03-01

    Full Text Available The danger of toxic organic pollutants in both aquatic and air environments calls for high-efficiency purification material. Herein, layered bismuth copper oxychalcogenides, BiCuSO, nanosheets of high photocatalytic activity were introduced to the PVDF (Polyvinylidene Fluoride. The fibrous membranes provide an easy, efficient, and recyclable way to purify organic pollutant. The physical and photophysical properties of the BiCuSO and its polymer composite were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, ultraviolet-visible diffuse reflection spectroscopy (DRS, X-ray photoelectron spectroscopy (XPS, electron spin resonance (EPR. Photocatalysis of Congo Red reveals that the BiCuSO/PVDF shows a superior photocatalytic activity of a 55% degradation rate in 70 min at visible light. The high photocatalytic activity is attributed to the exposed active {101} facets and the triple vacant associates V B i ‴ V O • • V B i ‴ . By engineering the intrinsic defects on the surface of bismuth oxysulfide, high solar-driven photocatalytic activity can be approached. The successful fabrication of the bismuth oxysulfide and its polymer nanocomposites provides an easy and general approach for high-performance purification materials for various applications.

  9. PARTIAL PURIFICATION AND CHARACTERIZATION OF ALKALOPHILIC PROTEASE FROM PSEUDOMONAS AERUGINOSA

    Directory of Open Access Journals (Sweden)

    R. Satheeskumar

    2013-10-01

    Full Text Available Partial purification and characterization of alkalophilic protease production from Pseudomonas aeruginosa was isolated from the gut of marine and coastal waters shrimp Penaeus monodon. The protease production was assayed in submerged fermentation to produce maximum protease activity (423 ± 0.09 U/ml. The enzyme was precipitated with ammonium sulphate and partially purified by ion exchange chromatography through DEAE Sephadex A-50 column. In 10th fraction showed maximum protease activity (734 ± 0.18 U/ml with increase in purification fold. The molecular weight of protease from Pseudomonas aeruginosa was recorded as 60 kDa. The stability of protease was tested at various pH and temperature; it showed maximum protease activity at pH-9 and temperature 50ºC. Among the various surfactants tested for enzyme stability, maximum activity was retained in poly ethylene glycol. The compatibility of protease enzyme with various commercial detergents; the enzyme retained maximum protease activity in tide. The results are indicated that all these properties make the bacterial proteases are most suitable for wide industrial applications.

  10. Properties of hydrogenase from Megasphaera elsdenii

    NARCIS (Netherlands)

    Dijk, van C.

    1980-01-01

    This thesis is concerned with the purification and properties of hydrogenase from the obligate anaerobic rumen bacterium Megasphaera elsdenii. In chapter 1 the motives underlying this thesis, the physiological role of hydrogenase in some heterotrophs, including

  11. Genomics of Probiotic Bacteria

    Science.gov (United States)

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  12. Isolation and purification of Cu-free methanobactin from Methylosinus trichosporium OB3b

    Directory of Open Access Journals (Sweden)

    Kraemer Stephan M

    2011-02-01

    Full Text Available Abstract Background The isolation of highly pure copper-free methanobactin is a prerequisite for the investigation of the biogeochemical functions of this chalkophore molecule produced by methane oxidizing bacteria. Here, we report a purification method for methanobactin from Methylosinus trichosporium OB3b cultures based on reversed-phase HPLC fractionation used in combination with a previously reported resin extraction. HPLC eluent fractions of the resin extracted product were collected and characterized with UV-vis, FT-IR, and C-1s NEXAFS spectroscopy, as well as with elemental analysis and ESI-MS. Results The results showed that numerous compounds other than methanobactin were present in the isolate obtained with resin extraction. Molar C/N ratios, mass spectrometry measurements, and UV-vis spectra indicated that methanobactin was only present in one of the HPLC fractions. On a mass basis, methanobactin carbon contributed only 32% to the total organic carbon isolated with resin extraction. Our spectroscopic results implied that besides methanobactin, the organic compounds in the resin extract comprised breakdown products of methanobactin as well as polysaccharide-like substances. Conclusion Our results demonstrate that a purification step is indispensable in addition to resin extraction in order to obtain pure methanobactin. The proposed HPLC purification procedure is suitable for semi-preparative work and provides copper-free methanobactin.

  13. Purification and characterization of xylanase from Aspergillus ...

    African Journals Online (AJOL)

    Xylanase was subjected to a three-step purification scheme involving ammonium sulphate precipitation, gel filtration chromatography and anion exchange chromatography. Purity was verified by running the extracted protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and a single band was ...

  14. Expression, purification and characterization of the interferon ...

    Indian Academy of Sciences (India)

    2012-01-19

    Jan 19, 2012 ... utilizing a single-step affinity purification with an appreciable yield of the highly purified protein. Recombinant RNase L was characterized by SDS-PAGE, immunoblotting and MALDI-TOF analysis. A semi-quantitative agarose-gel-based ribonuclease assay was developed for measuring its 2-5A-dependent ...

  15. Purification and characterization of circulating Onchocerca volvulus ...

    African Journals Online (AJOL)

    ... high antigen titres were separately pooled and subjected to affinity purification using immunosorbent columns prepared using human and rabbit anti-O. volvulus IgG antibodies. Eluates of purified circulating O. volvulus antigens were concentrated, and then the protein contents were determined using the Bradford method.

  16. Affinity purification of recombinant human plasminogen activator ...

    African Journals Online (AJOL)

    Purpose: To develop processes for effective isolation and purification of recombinant human plasminogen activator (rhPA) from transgenic rabbit milk. Methods: Immunoaffinity chromatography was selected and improved by a special polyol-responsive monoclonal antibody (PR-mAb). Alteplase was used as immunogen ...

  17. Expression and Purification of Soluble, Biologically Active ...

    African Journals Online (AJOL)

    Expression and Purification of Soluble, Biologically Active Recombinant Dipeptidyl Peptidase 4 (DPP4/CD26/ADAbp) Comprising the Extracellular Domain in the Yeast, Pichia ... Purpose: To investigate Pichia pastoris expression system for producing clinically usable, high-quality dipeptidyl peptidase 4 recombinant protein.

  18. Purification and characterisation of Cyclodextrin glycosyltransferase ...

    African Journals Online (AJOL)

    EXPER

    2012-06-05

    Jun 5, 2012 ... affinity chromatography were 25.8 and 17.8%, respectively. ... industrial applications according to its characteristic found in the current study. ..... and single step purification of cyclodextrin glycosyltransferase from alkalophilic Bacillus firmus by ion extchange chromatography. Biochem. Eng. J., 39: 510-515.

  19. Purification and Characterization of Thermostable Cellulase from ...

    African Journals Online (AJOL)

    CMCase was purified with ion-exchange and gel filtration chromatography. Results: Sequence-based identification of species belonging to the ... industrial application such as biofuel, animal feed industry, paper industry and clarification of fruit juices. Keywords: Thermostable cellulase, Sugarcane bagasse, Purification, ...

  20. Purification And Characterization Of Marine Bacillus Thuringiensis ...

    African Journals Online (AJOL)

    Urease was purified to homogeneity from Bacillus thuringiensis N2 using different purification steps namely, 55% acetone precipitation, DEAE-Sephadex A50 anion exchange column and Sephadex G120-200 gel filtration chromatography. The enzyme was purified 95.27 fold and showed a final specific activity of 10.48 ...

  1. Purification and Characterization of Thermostable Cellulase from ...

    African Journals Online (AJOL)

    ... after incubation at 80 °C for 60 min. Conclusion: Due to its high temperature stability, the purified XM70-CMCase may be useful for industrial application such as biofuel, animal feed industry, paper industry and clarification of fruit juices. Keywords: Thermostable cellulase, Sugarcane bagasse, Purification, Characterization ...

  2. Heparin affinity purification of extracellular vesicles

    NARCIS (Netherlands)

    Balaj, Leonora; Atai, Nadia A.; Chen, Weilin; Mu, Dakai; Tannous, Bakhos A.; Breakefield, Xandra O.; Skog, Johan; Maguire, Casey A.

    2015-01-01

    Extracellular vesicles (EVs) are lipid membrane vesicles released by cells. They carry active biomolecules including DNA, RNA, and protein which can be transferred to recipient cells. Isolation and purification of EVs from culture cell media and biofluids is still a major challenge. The most widely

  3. Purification and characterization of a thermostable glucoamylase ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-06-07

    Jun 7, 2010 ... Department of Biology, Faculty of Science and Arts, Adnan Menderes University, 09010, Aydın, Turkey. ... Raw corn starch adsorption of GA was found ...... GP-21 in solid state fermentation. J. Ind. Microbiol. Biotechnol. 22: 622-626. Mamo G, Gessesse A (1999b). Purification and characterization of two.

  4. Isolation, purification and effects of hypoglycemic functional ...

    African Journals Online (AJOL)

    user

    2012-04-12

    Apr 12, 2012 ... Key words: Hypoglycemic activity, polysaccharides, Inonotus obliquus, isolation, purification. INTRODUCTION. Obesity, high blood glucose and diabetes which are the significant chronic diseases and causes of death in modern society and they are largely caused by diet. Worldwide, scientists have focused ...

  5. Partial purification and characterization of polygalacturonase ...

    African Journals Online (AJOL)

    Partial purification and characterization of polygalacturonase-inhibitor proteins from pearl millet. ... Protein separation of the two peaks by gel electrophoresis showed prominent bands between 29 and 43 kDa, consistent with the molecular weights of the known plant PGIPs. The two PGIP peaks were further studied for their ...

  6. Partial purification and biochemical characterization of acid ...

    African Journals Online (AJOL)

    Mung bean (Vigna radiata) is one of the important crops of the North Eastern Region of India. In the present study, acid phosphatase enzyme was isolated and partially purified from germinated local mung bean seeds. The sequential partial purification process was performed using ammonium sulphate precipitation method.

  7. Purification of functionalized DNA origami nanostructures.

    Science.gov (United States)

    Shaw, Alan; Benson, Erik; Högberg, Björn

    2015-05-26

    The high programmability of DNA origami has provided tools for precise manipulation of matter at the nanoscale. This manipulation of matter opens up the possibility to arrange functional elements for a diverse range of applications that utilize the nanometer precision provided by these structures. However, the realization of functionalized DNA origami still suffers from imperfect production methods, in particular in the purification step, where excess material is separated from the desired functionalized DNA origami. In this article we demonstrate and optimize two purification methods that have not previously been applied to DNA origami. In addition, we provide a systematic study comparing the purification efficacy of these and five other commonly used purification methods. Three types of functionalized DNA origami were used as model systems in this study. DNA origami was patterned with either small molecules, antibodies, or larger proteins. With the results of our work we aim to provide a guideline in quality fabrication of various types of functionalized DNA origami and to provide a route for scalable production of these promising tools.

  8. Purification, Characterization and Antibacterial Mechanism of ...

    African Journals Online (AJOL)

    Purpose: To carry out the extraction, purification and biological characterization, and assess the antibacterial activity of bacteriocin from Lactobacillus acidophilus XH1. Methods: Chloroform extraction method was used for bacteriocin extraction while characterization of bacteriocin was carried out by flat-dug well agar ...

  9. Charge, size distribution and hydrophobicity of viruses: Effect of propagation and purification methods.

    Science.gov (United States)

    Shi, Hang; Tarabara, Volodymyr V

    2018-02-10

    Two virus propagation methods (in broth and on double agar overlay) and three purification procedures (PEG precipitation, centrifugal diafiltration and CsCl density gradient centrifugation) were comparatively evaluated using MS2 and P22 bacteriophages as model viruses. The prepared stocks were characterized in terms of electrophoretic mobility as a function of pH, particle size distribution, surface tension components and overall hydrophobicity of the virus, as well as the percentage of infectious and total virus recovered. The obtained data were used to rank the purification methods according to six criteria of likely practical relevance. Regardless of the purification method applied, virus propagation in broth media resulted in higher purity virus stocks as the growth on double agar overlay introduced difficult-to-remove residual agar. CsCl density gradient centrifugation gave the highest quality bacteriophage suspensions, recovered infectious P22 at least as efficiently as the other two purification methods and selected for intact P22 virions over damaged ones. The impurities remaining in the virus suspension after PEG precipitation and centrifugal diafiltration broadened the size distribution and interfered with electrophoretic mobility measurements. The residual impurities had a major impact on the free energy of virus-virus interfacial interaction (the quantitative measure of virus hydrophobicity/hydrophilicity) leading to an incorrect determination of P22 bacteriophage as hydrophilic. The trends in measured physicochemical properties can be rationalized by considering impurity-coated virions as permeable soft particles. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. A new methodology to determine the isoeluotropic conditions on ultra-performance flash purification stationary phases from analytical reversed liquid chromatography stationary phase.

    Science.gov (United States)

    Héron, Sylvie; Charbonneau, Didier; Albisson, Pauline; Estievenart, Guillaume; Groni, Sihem; Tchapla, Alain

    2015-06-05

    Nowadays, the determination of the experimental chromatographic conditions to be used in Reversed Phase Liquid Ultra-Performance Flash Purification is still challenging. This is due to four different items. In most cases, flash purification stationary phases are not available with geometry of column used in analytical chromatography. The flash purification columns are single-use only. From the point of view of selectivity and retention, few RPLC phases exist with properties of separation identical for analytical and flash purification supports. Characterization methods and databases used for comparing analytical RPLC columns do not include stationary phases for RP flash purification columns. The goal of this work is to develop a new method development strategy which permits the determination of the experimental chromatographic conditions on RP ultra-performance flash purification columns. It relies on the knowledge of any isocratic conditions obtained on any given initial reversed stationary phase. The final conditions to implement on the RP ultra-performance flash purification phase enable either to keep the retention range of a selected solute constant, or to set it around a previously chosen value. The rules of transfer in linear gradient mode are also described. The methodology was valid, whatever the initial RP stationary and mobile phases, for different chemical classes, whatever the bonding, particle diameter, porous or core shell particle, towards different RP alkyl and analogues stationary and mobile phases. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Property (

    CERN Document Server

    Ershov, Mikhail; Kassabov, Martin

    2017-01-01

    The authors introduce and study the class of groups graded by root systems. They prove that if \\Phi is an irreducible classical root system of rank \\geq 2 and G is a group graded by \\Phi, then under certain natural conditions on the grading, the union of the root subgroups is a Kazhdan subset of G. As the main application of this theorem the authors prove that for any reduced irreducible classical root system \\Phi of rank \\geq 2 and a finitely generated commutative ring R with 1, the Steinberg group {\\mathrm St}_{\\Phi}(R) and the elementary Chevalley group \\mathbb E_{\\Phi}(R) have property (T). They also show that there exists a group with property (T) which maps onto all finite simple groups of Lie type and rank \\geq 2, thereby providing a "unified" proof of expansion in these groups.

  12. How honey kills bacteria

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; te Velde, Anje A.; de Boer, Leonie; Speijer, Dave; Vandenbroucke-Grauls, Christina M. J. E.; Zaat, Sebastian A. J.

    2010-01-01

    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria

  13. [Separation and purification of proanthocyanidins from rose by macroporous resins].

    Science.gov (United States)

    Yao, Yu-cui; Li, Xiang-rong

    2008-08-01

    To study the separation and purification technology for proanthocyanidins from rose and establish the best operating conditions. Evaluated by static adsorption capacity and elution ratio, five types of macroporous resins including D101, D1300, NKA, AB-8, NKA-II were tested to separate and purify proanthocyanidins. And evaluated by product purity, the concentration of extract sample, pH of extract sample, concentration of eluant and flow rate of elution had been investigated. D101 type macroporous resin showed the best property and was suitable for purifying proanthocyanidins from rose. The best operating conditions were as follows: 1.25 mg/ml as the concentration of extract sample, 2 as the pH value of extract sample, 70% ethanol equeous solution as the eluant and 2 ml/min as the flow rate of elution. This study can supply a method to separate and purify proanthocyanidins from rose.

  14. Purification Of Water From Nsukka Water Pond Using Solar Still.

    Directory of Open Access Journals (Sweden)

    Ugwuoke E.C

    2015-08-01

    Full Text Available Abstract This work presents the analysis of a solar water distillation system. There is important need for good drinking water in the world today due to harmful effect of water borne diseases. Most water from rivers ponds seas are either salty or brackish and require purification before drinking. The water used in this work is collected from pond at Nsukka Urban and the experiment was performed at University of Nigeria Nsukka. Twenty litres of water was used for the experiment and 4 litres was obtained as the maximum volume after 10 days .The average temperature recorded during the experiment was 29C. The chemical and physical properties of the distillate correspond to world Health Organization Standard.

  15. Purification and characterization of amine oxidase from soybean seedlings.

    Science.gov (United States)

    Vianello, F; Di Paolo, M L; Stevanato, R; Gasparini, R; Rigo, A

    1993-11-15

    A simple and rapid procedure for purification of soybean seedling amine oxidase is reported. The crude enzyme, obtained by ammonium sulfate fractionation was purified by ion-exchange chromatography on a cellulose phosphate column and batch affinity chromatography on 6-aminohexyl-Sepharose. Cyclohexylamine, a competitive inhibitor, was utilized to elute the enzyme. A homogeneous enzyme was obtained with a yield higher than 25%, the content of minor components being lauryl sulfate-polyacrylamide gel electrophoresis. The enzyme is a dimer and contains two Cu2+ ion per molecule. Its EPR spectrum is typical of Cu2+ in a tetragonal symmetry. The enzyme oxidizes cadaverine at high rate, the specific activity being 4.3 mukat/mg. Molecular, spectroscopic, and kinetic properties of this enzyme are reported.

  16. Partial purification and characterization of the glucagon receptor

    International Nuclear Information System (INIS)

    Horuk, R.; Wright, D.E.

    1983-01-01

    Specific labeling of liver plasma membrane glucagon receptors has been achieved by the photoincorporation of a 125 I-labeled photoderivative of glucagon, Nsup(E)-4-azidophenylamidinoglucagon. Identification of glucagon receptors was facilitated by irradiating membranes in the presence of excess unlabeled glucagon. Isoelectric focusing of radioiodinated membrane proteins revealed one major band of glucagon displaceable material which had an isoelectric point of 5.85. When this material was isolated and run on SDS-polyacrylamide gels a major labeled band of Msub(r) 55000 was obtained which had properties consistent with those of the glucagon receptor. These studies indicate that a purification of the glucagon receptor of >700-fold can be attained through the use of isoelectric focusing and SDS-polyacrylamide electrophoresis. (Auth.)

  17. The Mycoplasma arthritidis superantigen MAM: purification and identification of an active peptide.

    OpenAIRE

    Atkin, C L; Wei, S; Cole, B C

    1994-01-01

    The prototypical superantigen MAM is an extracellular T-cell mitogen produced by Mycoplasma arthritidis, an organism which causes chronic proliferative arthritis of rodents. We here describe purification of MAM to homogeneity. Pure MAM exhibits all of the major properties previously described for partially purified MAM, including preference for H-2E molecules in presention to T cells, V beta T-cell receptor specificity for T-cell activation, and in vivo inhibition of T-cell functions but enha...

  18. On the use of magnetic separation for purification of aqueous radioactive solutions from oils

    International Nuclear Information System (INIS)

    Shchebetkovskij, V.N.; Vyatkin, V.E.; Gurevich, D.M.; Bochkov, A.A.

    1984-01-01

    Using model systems, simulating oiled condensate that is formed during evaporation of water radioactive wastes, a possibility is shown to use the method of magnetic separation for waste purification from oil. Introduction of a dispersed ferromagnetic powder in the system to stabilize oil drops and to impart ''quasiferromagnetic'' properties to them, is a necessary condition for the efficient oil separation. Using as an example 137 Cs absorption, the adsorbability of ferromagnetic powders relative to radionuclides in the system investigated is assessed

  19. Sealed operation, and circulation and purification of gas in the HARPO TPC

    Science.gov (United States)

    Frotin, M.; Gros, P.; Attié, D.; Bernard, D.; Dauvois, V.; Delbart, A.; Durand, D.; Geerebaert, Y.; Legand, S.; Magnier, P.; Poilleux, P.; Semeniouk, I.

    2018-02-01

    HARPO is a time projection chamber (TPC) demonstrator of a gamma-ray telescope and polarimeter in the MeV-GeV range, for a future space mission. We present the evolution of the TPC performance over a five month sealed-mode operation, by the analysis of cosmic-ray data, followed by the fast and complete recovery of the initial gas properties using a lightweight gas circulation and purification system.

  20. Initiation of protein synthesis by folate-sufficient and folate-deficient Streptococcus faecalis R: partial purification and properties of methionyl-transfer ribonucleic acid synthetase and methionyl-transfer ribonucleic acid formyltransferase.

    Science.gov (United States)

    Samuel, C E; Rabinowitz, J C

    1974-04-01

    The initiation of protein synthesis by Streptococcus faecalis R grown in folate-free culture occurs without N-formylation or N-acylation of methionyl-tRNA(f) (Met). Methionyl-tRNA synthetase and methionyl-tRNA formyltransferase were partially purified from S. faecalis grown under normal culture conditions in the presence of folate (plus-folate); the general properties of the enzymes were determined and compared with the properties of the enzymes purified from wild-type cells grown in the absence of folate (minus-folate). S. faecalis methionyl-tRNA synthetase displays optimal activity at pH values between 7.2 and 7.8, requires Mg(2+), and has an apparent molecular weight of 106,000, as determined by gel filtration, and 127,000, as determined by sucrose density gradient centrifugation. The K(m) values of plus-folate methionyl-tRNA synthetase for each of the three substrates in the aminoacylation reaction (l-methionine, adenosine triphosphate, and tRNA) are nearly identical to the respective substrate Michaelis constants of minus-folate methionyl-tRNA synthetase. Furthermore, both plus- and minus-folate S. faecalis methionyl-tRNA synthetases catalyze, at equal rates, the aminoacylation of tRNA(f) (Met) and tRNA(m) (Met) isolated from either plus-folate or minus-folate cells. S. faecalis methionyl-tRNA formyltransferase displays optimal activity at pH values near 7.0, is stimulated by Mg(2+), and has an apparent molecular weight of approximately 29,900 when estimated by sucrose density gradient centrifugation. The K(m) value of plus-folate formyltransferase for plus-folate Met-tRNA(f) (Met) does not differ significantly from that of minus-folate formyltransferase for minus-folate Met-tRNA(f) (Met). Both enzymes can utilize either 10-formyltetrahydrofolate or 10-formyltetrahydropteroyltriglutamate as the formyl donor; the Michaelis constant for the monoglutamyl pteroyl coenzyme is slightly less than that of the triglutamyl pteroyl coenzyme for both transformylases

  1. Early Detection of Biofouling on Water Purification Membranes by Ambient Ionization Mass Spectrometry Imaging.

    Science.gov (United States)

    Jakka Ravindran, Swathy; Kumar, Ramesh; Srimany, Amitava; Philip, Ligy; Pradeep, Thalappil

    2018-01-02

    By direct analysis of water purification membranes using ambient ionization mass spectrometry, an attempt has been made to understand the molecular signatures of bacterial fouling. Membrane based purification methods are used extensively in water treatment, and a major challenge for them is biofouling. The buildup of microbes and their extracellular polymeric matrix clog the purification membranes and reduce their efficiency. To understand the early stages of bacterial fouling on water purification membranes, we have used desorption electrospray ionization mass spectrometry (DESI MS), where ion formation occurs in ambient conditions and the ionization event is surface sensitive. Biosurfactants at the air-water interface generated by microorganisms as a result of quorum sensing, influence the water-membrane interface and are important for the bacterial attachment. We show that these biosurfactants produced by bacteria can be indicator molecular species signifying initiation of biofilms on membrane surfaces, demonstrated by specific DESI MS signatures. In Pseudomonas aeruginosa, one of the best studied models for biofilm formation, this process is mediated by rhamnolipids forewarning bacterial fouling. Species dependent variation of such molecules can be used for the precise identification of the microorganisms, as revealed by studies on P. aeroginosa (ATCC 25619). The production of biosurfactants is tightly regulated at the transcriptional level by the quorum-sensing (QS) response. Thus, secretion of these extracellular molecules across the membrane surface allows rapid screening of the biofilm community. We show that, the ambient ionization mass spectrometry can detect certain toxic heavy metals present in water, using surfactant-metal complexes as analytes. We believe that such studies conducted on membranes in various input water streams will help design suitable membrane processes specific to the input streams.

  2. Multi-hop conjugation based bacteria nanonetworks.

    Science.gov (United States)

    Balasubramaniam, Sasitharan; Lio', Pietro

    2013-03-01

    Molecular communication is a new paradigm for nanomachines to exchange information, by utilizing biological mechanism and/or components to transfer information (e.g., molecular diffusion, neuronal networks, molecular motors). One possible approach for molecular communication is through the use of bacteria, which can act as carriers for DNA-based information, i.e., plasmids. This paper analyzes multi-hop molecular nanonetworks that utilize bacteria as a carrier. The proposed approach combines different properties of bacteria to enable multi-hop transmission, such as conjugation and chemotaxis-based motility. Various analyses have been performed, including the correlation between the success rate of plasmid delivery to the destination node, and the role of conjugation in enabling this; as well as analyses on the impact of large topology shapes (e.g., Grid, Random, and Scale-free) on the success rate of plasmid delivery for multiple source-destination nanonetworks. A further solution proposed in this paper is the application of antibiotics to act as filters on illegitimate messages that could be delivered by the bacteria. Our evaluation, which has been conducted through a series of simulations, has shown that numerous bacteria properties fit to properties required for communication networking (e.g., packet filtering, routing, addressing).

  3. Simplified, enhanced protein purification using an inducible, autoprocessing enzyme tag.

    Directory of Open Access Journals (Sweden)

    Aimee Shen

    2009-12-01

    Full Text Available We introduce a new method for purifying recombinant proteins expressed in bacteria using a highly specific, inducible, self-cleaving protease tag. This tag is comprised of the Vibrio cholerae MARTX toxin cysteine protease domain (CPD, an autoprocessing enzyme that cleaves exclusively after a leucine residue within the target protein-CPD junction. Importantly, V. cholerae CPD is specifically activated by inositol hexakisphosphate (InsP(6, a eukaryotic-specific small molecule that is absent from the bacterial cytosol. As a result, when His(6-tagged CPD is fused to the C-terminus of target proteins and expressed in Escherichia coli, the full-length fusion protein can be purified from bacterial lysates using metal ion affinity chromatography. Subsequent addition of InsP(6 to the immobilized fusion protein induces CPD-mediated cleavage at the target protein-CPD junction, releasing untagged target protein into the supernatant. This method condenses affinity chromatography and fusion tag cleavage into a single step, obviating the need for exogenous protease addition to remove the fusion tag(s and increasing the efficiency of tag separation. Furthermore, in addition to being timesaving, versatile, and inexpensive, our results indicate that the CPD purification system can enhance the expression, integrity, and solubility of intractable proteins from diverse organisms.

  4. Production and Purification Immunoglobulin against E. coli in Egg Yolk

    Directory of Open Access Journals (Sweden)

    Mohammadreza Nassiri

    2016-08-01

    presence of antibody IgY was confirmed using SDS-PAGE. Purification of IgY was carried out by polyethylene glycol precipitation method using PEG 6000 powder (Merck, Germany based on method of Polson. The purified IgY against E. coli was separated using 10% SDS-PAGE. In order to investigate the effect of the specific anti-E. Coli antibody, mice (Razi, Institute of Iran were randomly distributed into five experimental groups (6mice/group. The mice were kept in conventional animal facilities and received water and food ad libitum. All animal care and procedures were in accordance with institutional policies for animal health and well-being. Experimental groups were including group 1 (mice received IgY orally in drinking water 72 hours before intraperitoneal injection of bacteria and then injected intraperitoneally with 0.5 ml of bacteria E. coli O157: H7, group 2 (mice received IgY orally in drinking water 72 hours before the injection and then injected intraperitoneally with 0.5 ml of deionized water, group 3 (0.5 ml of E. coli O157: H7 incubated with 0.5 ml of the specific anti-E. coli IgY and then 0.5 ml of the incubated solution injected to mice intraperitoneally, group 4 (mice injected with 0.5 ml of IgY and group 5 (mice received 0.5 ml of E. coli O157: H7. Results and Discussion We obtained specific egg yolk antibody against E. coli O157: H7 by immunizing hens with the killed E. coli O157: H7 antigen. The results showed that the IgY was successfully purified from egg yolk. SDS-PAGE analysis showed presence of protein bands 27kDa and 67 kDa of IgY, which correspond to IgY light and heavy chains. Effects of IgY on mice showed that mice received IgY orally in drinking water 72 hours before intraperitoneal injection were protected against bacteria. Also, when specific anti-E. coli IgY was incubated with E.coli O157: H7 for 24 hours and then it was injected to mice led to mice protected against bacteria. The results of our study were agreement with the results of Chae et al

  5. Purification and partial genome characterization of the bacterial endosymbiont Blattabacterium cuenoti from the fat bodies of cockroaches

    Directory of Open Access Journals (Sweden)

    Yamada Akinori

    2008-11-01

    Full Text Available Abstract Background Symbiotic relationships between intracellular bacteria and eukaryotes are widespread in nature. Genome sequencing of the bacterial partner has provided a number of key insights into the basis of these symbioses. A challenging aspect of sequencing symbiont genomes is separating the bacteria from the host tissues. In the present study, we describe a simple method of endosymbiont purification from complex environment, using Blattabacterium cuenoti inhabiting in cockroaches as a model system. Findings B. cuenoti cells were successfully purified from the fat bodies of the cockroach Panesthia angustipennis by a combination of slow- and fast-speed centrifugal fractionations, nylon-membrane filtration, and centrifugation with Percoll solutions. We performed pulse-field electrophoresis, diagnostic PCR and random sequencing of the shoutgun library. These experiments confirmed minimal contamination of host and mitochondrial DNA. The genome size and the G+C content of B. cuenoti were inferred to be 650 kb and 32.1 ± 7.6%, respectively. Conclusion The present study showed successful purification and characterization of the genome of B. cuenoti. Our methodology should be applicable for future symbiont genome sequencing projects. An advantage of the present purification method is that each step is easily performed with ordinary microtubes and a microcentrifuge, and without DNase treatment.

  6. Combination of membrane technologies for purification of L (+) - lactic acid from juice of banana (Musa AAA, variety Cavendish cultivar Gram naine) obtained from an agroindustrial waste

    International Nuclear Information System (INIS)

    Murillo Viera, Esteban

    2013-01-01

    The process that has allowed recovery and purification of the L (+)-acid present in the juice fermented waste produced from banana was developed, treated enzymatically, using tangential nanofiltration. The effect of the enzymatic treatment was evaluated on physical chemical parameters of fermented banana juice. The process parameters of centrifugal clarification and microfiltration were characterized on banana juice as activities prior operations to recovery and purification of lactic acid. The temperature and the transmembrane pressure on the permeate flow and the performance of recovery and purification of lactic acid were evaluated by the ultrafiltration and nanofiltration processes. The properties physico-chemical the banana juice fermented and of the liquid filtrate obtained at the stage recovery and purification of lactic acid were compared by ultrafiltration [es

  7. Effect of Different Purification Techniques on the Characteristics of Heteropolysaccharide-Protein Biopolymer from Durian (Durio zibethinus Seed

    Directory of Open Access Journals (Sweden)

    Hamed Mirhosseini

    2012-09-01

    Full Text Available Natural biopolymers from plant sources contain many impurities (e.g., fat, protein, fiber, natural pigment and endogenous enzymes, therefore, an efficient purification process is recommended to minimize these impurities and consequently improve the functional properties of the biopolymer. The main objective of the present study was to investigate the effect of different purification techniques on the yield, protein content, solubility, water- and oil-holding capacity of a heteropolysaccharide-protein biopolymer obtained from durian seed. Four different purification methods using different chemicals and solvents (i.e., A (isopropanol and ethanol, B (isopropanol and acetone, C (saturated barium hydroxide, and D (Fehling solution] to liberate the purified biopolymer from its crude form were compared. In most cases, the purification process significantly (p < 0.05 improved the physicochemical properties of heteropolysaccharide-protein biopolymer from durian fruit seed. The present work showed that the precipitation using isopropanol and acetone (Method B resulted in the highest purification yield among all the tested purification techniques. The precipitation using saturated barium hydroxide (Method C led to induce the highest solubility and relatively high capacity of water absorption. The current study reveals that the precipitation using Fehling solution (Method D most efficiently eliminates the protein fraction, thus providing more pure biopolymer suitable for biological applications.

  8. Isolation and life cycle characterization of lytic viruses infecting heterotrophic bacteria and cyanobacteria

    DEFF Research Database (Denmark)

    Middelboe, Mathias; Chan, Amy; Bertelsen, Sif Koldborg

    2010-01-01

    Basic knowledge on viruses infecting heterotrophic bacteria and cyanobacteria is key to future progress in understanding the role of viruses in aquatic systems and the influence of virus–host interactions on microbial mortality, biogeochemical cycles, and genetic exchange. Such studies require...... the isolation, propagation, and purification of host–virus systems. This contribution presents some of the most widely used methodological approaches for isolation and purification of bacteriophages and cyanophages, the first step in detailed studies of virus–host interactions and viral genetic composition......, and discusses the applications and limitations of different isolation procedures. Most work on phage isolation has been carried out with aerobic heterotrophic bacteria and cyanobacteria, culturable both on agar plates and in enriched liquid cultures. The procedures presented here are limited to lytic viruses...

  9. Antibiotics from predatory bacteria

    Directory of Open Access Journals (Sweden)

    Juliane Korp

    2016-03-01

    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  10. Rapid cloning and purification of proteins: gateway vectors for protein purification by self-cleaving tags.

    Science.gov (United States)

    Gillies, Alison R; Hsii, Judy F; Oak, Seachol; Wood, David W

    2008-10-01

    We have combined Invitrogen's Gateway cloning technology with self-cleaving purification tags to generate a new system for rapid production of recombinant protein products. To accomplish this, we engineered our previously reported DeltaI-CM cleaving intein to include a Gateway cloning recognition sequence, and demonstrated that the resulting Gateway-competent intein is unaffected. This intein can therefore be used in several previously reported purification methods, while at the same time being compatible with Gateway cloning. We have incorporated this intein into a set of Gateway vectors, which include self-cleaving elastin-like polypeptide (ELP), chitin binding domain (CBD), phasin (polyhydroxybutyrate-binding), or maltose binding domain (MBD) tags. These vectors were verified by Gateway cloning of TEM-1 beta-lactamase and Escherichia coli catalase genes, and the expressed target proteins were purified using the four methods encoded on the vectors. The purification methods were unaffected by replacing the DeltaI-CM intein with the Gateway intein. It was observed that some purification methods were more appropriate for each target than others, suggesting utility of this technology for rapid process identification and optimization. The modular design of the Gateway system and intein purification method suggests that any tag and promoter can be trivially added to this system for the development of additional expression vectors. This technology could greatly facilitate process optimization, allowing several targets and methods to be tested in a high-throughput manner.

  11. Efficient biotinylation and single-step purification of tagged transcription factors in mammalian cells and transgenic mice

    Science.gov (United States)

    de Boer, Ernie; Rodriguez, Patrick; Bonte, Edgar; Krijgsveld, Jeroen; Katsantoni, Eleni; Heck, Albert; Grosveld, Frank; Strouboulis, John

    2003-06-01

    Proteomic approaches require simple and efficient protein purification methodologies that are amenable to high throughput. Biotinylation is an attractive approach for protein complex purification due to the very high affinity of avidin/streptavidin for biotinylated templates. Here, we describe an approach for the single-step purification of transcription factor complex(es) based on specific in vivo biotinylation. We expressed the bacterial BirA biotin ligase in mammalian cells and demonstrated very efficient biotinylation of a hematopoietic transcription factor bearing a small (23-aa) artificial peptide tag. Biotinylation of the tagged transcription factor altered neither the factor's protein interactions or DNA binding properties in vivo nor its subnuclear distribution. Using this approach, we isolated the biotin-tagged transcription factor and at least one other known interacting protein from crude nuclear extracts by direct binding to streptavidin beads. Finally, this method works efficiently in transgenic mice, thus raising the prospect of using biotinylation tagging in protein complex purification directly from animal tissues. Therefore, BirA-mediated biotinylation of tagged proteins provides the basis for the single-step purification of proteins from mammalian cells.

  12. Hydrogen production by nonphotosynthetic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Huang, S.D.; Secor, C.K.; Zweig, R.M.; Ascione, R.

    1984-01-01

    H-producing nonphotosynthetic bacteria are identified and H from sewage treatment plants, H from rumen bacteria, and large-scale production of H through the genetic manipulation of H-producing nonphotosynthetic bacteria are discussed. (Refs. 36).

  13. HOUSEHOLD PURIFICATION OF FLUORIDE CONTAMINATED MAGADI (TRONA)

    DEFF Research Database (Denmark)

    Nielsen, Joan Maj; Dahi, Elian

    1997-01-01

    Purification of fluoride contaminated magadi is studied using bone char sorption and calcium precipitation. The bone char treatment is found to be workable both in columns and in batches where the magadi is dissolved in water prior to treatment. The concentrations in the solutions were 89 g magadi....../L and 95 and 400 mg F/L respectively in natural and synthetic solutions. The fluoride removal capacities observed were 4.6 mg F/g bone char for the column system and 2.7 mg F/g bone char for the batch system in case of synthetic magadi solution. It is however concluded that the batch system is the best...... treatment method. A procedure for purification of fluoride contaminated magadi at household level is described....

  14. The Viability of Photocatalysis for Air Purification

    Directory of Open Access Journals (Sweden)

    Stephen O. Hay

    2015-01-01

    Full Text Available Photocatalytic oxidation (PCO air purification technology is reviewed based on the decades of research conducted by the United Technologies Research Center (UTRC and their external colleagues. UTRC conducted basic research on the reaction rates of various volatile organic compounds (VOCs. The knowledge gained allowed validation of 1D and 3D prototype reactor models that guided further purifier development. Colleagues worldwide validated purifier prototypes in simulated realistic indoor environments. Prototype products were deployed in office environments both in the United States and France. As a result of these validation studies, it was discovered that both catalyst lifetime and byproduct formation are barriers to implementing this technology. Research is ongoing at the University of Connecticut that is applicable to extending catalyst lifetime, increasing catalyst efficiency and extending activation wavelength from the ultraviolet to the visible wavelengths. It is critical that catalyst lifetime is extended to realize cost effective implementation of PCO air purification.

  15. Development of partitioning process: purification of DIDPA

    International Nuclear Information System (INIS)

    Watanabe, Masayuki; Morita, Yasuji; Kubota, Masumitsu

    1998-04-01

    The partitioning process has developed and demonstrated that the solvent extraction with diisodecylphosphoric acid (DIDPA) can successfully separate transuranium elements from a high-level liquid waste. In the solvent extraction, DIDPA is decomposed by radiolysis and hydrolysis. The main degradation product is monoisodecyl phosphoric acid (MIDPA). Ethylene glycol has been used for removing the product by a solvent extraction method. However this method has two drawbacks that two phases separate slowly and the used ethylene glycol is not regeneratable. First it was found that the addition of acetone or methanol with 20 volume % improved the phase separation. Then a new purification method was developed by using an aqueous solution of methanol or acetone. The new purification method is as excellent as the ethylene glycol method for the removal of MIDPA. (author)

  16. Antimutagenicity of fermented milk with lactic acid bacteria

    OpenAIRE

    細野, 明義; Akiyoshi, Hosono; 信州大学大学院農学研究科; Graduate School of Agriculture, Shinshu University

    2002-01-01

    Fermented milk and lactic acid bacteria have been considered to provide potential health benefits to human beings. Milk containing casein has been shown to be highly antimutagenic, and fermentation by lactic acid bacteria produces various hydrolytic peptides which contribute to the high antimutagenicity of fermented milk. The antimutagenic property of fermented milk was dependent on the strains of lactic acid bacteria and the fermentation time. Not only the proteolytic products of casein, but...

  17. Entanglement of purification: from spin chains to holography

    Science.gov (United States)

    Nguyen, Phuc; Devakul, Trithep; Halbasch, Matthew G.; Zaletel, Michael P.; Swingle, Brian

    2018-01-01

    Purification is a powerful technique in quantum physics whereby a mixed quantum state is extended to a pure state on a larger system. This process is not unique, and in systems composed of many degrees of freedom, one natural purification is the one with minimal entanglement. Here we study the entropy of the minimally entangled purification, called the entanglement of purification, in three model systems: an Ising spin chain, conformal field theories holographically dual to Einstein gravity, and random stabilizer tensor networks. We conjecture values for the entanglement of purification in all these models, and we support our conjectures with a variety of numerical and analytical results. We find that such minimally entangled purifications have a number of applications, from enhancing entanglement-based tensor network methods for describing mixed states to elucidating novel aspects of the emergence of geometry from entanglement in the AdS/CFT correspondence.

  18. Purification of crude biodiesel using dry washing and membrane technologies

    Directory of Open Access Journals (Sweden)

    I.M. Atadashi

    2015-12-01

    Full Text Available Purification of crude biodiesel is mandatory for the fuel to meet the strict international standard specifications for biodiesel. Therefore, this paper carefully analyzed recently published literatures which deal with the purification of biodiesel. As such, dry washing technologies and the most recent membrane biodiesel purification process have been thoroughly examined. Although purification of biodiesel using dry washing process involving magnesol and ion exchange resins provides high-quality biodiesel fuel, considerable amount of spent absorbents is recorded, besides the skeletal knowledge on its operating process. Further, recent findings have shown that biodiesel purification using membrane technique could offer high-quality biodiesel fuel with less wastewater discharges. Thus, both researchers and industries are expected to benefit from the development of membrane technique in purifying crude biodiesel. As well biodiesel purification via membranes has been shown to be environmentally friendly. For these reasons, it is important to explore and exploit membrane technology to purify crude biodiesel.

  19. Conductive diamond electrodes for water purification

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Martínez-Huitle

    2007-12-01

    Full Text Available Nowadays, synthetic diamond has been studied for its application in wastewater treatment, electroanalysis, organic synthesis and sensor areas; however, its use in the water disinfection/purification is its most relevant application. The new electrochemistry applications of diamond electrodes open new perspectives for an easy, effective, and chemical free water treatment. This article highlights and summarizes the results of a selection of papers dealing with electrochemical disinfection using synthetic diamond films.

  20. Propagation and Purification of Baculovirus oryctes Huger

    Directory of Open Access Journals (Sweden)

    Susamto Somowiyarjo

    1995-12-01

    Full Text Available An isolate of Baculovirus oryctes, a possible biological control agent for coconut beetle (Oryctes rhinoceros Huger from East Java was propagated and purified. The virus could be transmitted by feeding the imago with 10% sucrose containing virus from homogenate of infected beetles. Effectivity of virus to 9 healthy females by sexual copulation. Virus be succesfully purified by a method of Payne. Key words: Baculovirus oryctes, transmission, purification

  1. EXTRACTION, PURIFICATION ET CARACTERISATION DE DEUX ...

    African Journals Online (AJOL)

    AISA

    cristallinité, son complexe avec la lignine et les autres composés qui lui sont associés. (Arunik et al., 1988). Pour pouvoir hydrolyser les polymères naturels, nous avons entrepris l'extraction, la purification, l'homogénéisation et la déter- mination des propriétés physico-chimiques de deux cellulases des ouvriers du termite ...

  2. Molecular characterization of the phenolic acid metabolism in the lactic acid bacteria Lactobacillus plantarum

    OpenAIRE

    Barthelmebs, Lise; Diviés, Charles; Cavin, Jean-François

    2001-01-01

    International audience; The lactic acid bacteria Lactobacillus plantarum displays substrate-inducible decarboxylase activities on $p$-coumaric, caffeic and ferulic acids. Purification of the $p$-coumaric acid decarboxylase (PDC) was performed. Sequence of the N-terminal part of the PDC led to the cloning of the corresponding pdc gene. Expression of this gene in Escherichia coli revealed that PDC displayed a weak activity on ferulic acid, detectable in vitro in the presence of ammonium sulfate...

  3. Filamentous bacteria transport electrons over centimetre distances

    DEFF Research Database (Denmark)

    Pfeffer, Christian; Larsen, Steffen; Song, Jie

    2012-01-01

    across centimetre-wide zones. Here we present evidence that the native conductors are long, filamentous bacteria. They abounded in sediment zones with electric currents and along their length they contained strings with distinct properties in accordance with a function as electron transporters. Living...

  4. [Darwin and bacteria].

    Science.gov (United States)

    Ledermann D, Walter

    2009-02-01

    As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

  5. Extracellular communication in bacteria

    DEFF Research Database (Denmark)

    Chhabra, S.R.; Philipp, B.; Eberl, L.

    2005-01-01

    molecules, in different Gram-positive and Gram-negative bacteria they control pathogenicity, secondary metabolite production, biofilm differentiation, DNA transfer and bioluminescence. The development of biosensors for the detection of these signal molecules has greatly facilitated their subsequent chemical...

  6. In Situ Electron Microscopy of Lactomicroselenium Particles in Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Gabor Nagy

    2016-06-01

    Full Text Available Electron microscopy was used to test whether or not (a in statu nascendi synthesized, and in situ measured, nanoparticle size does not differ significantly from the size of nanoparticles after their purification; and (b the generation of selenium is detrimental to the bacterial strains that produce them. Elemental nano-sized selenium produced by probiotic latic acid bacteria was used as a lactomicroselenium (lactomicroSel inhibitor of cell growth in the presence of lactomicroSel, and was followed by time-lapse microscopy. The size of lactomicroSel produced by probiotic bacteria was measured in situ and after isolation and purification. For these measurements the TESLA BS 540 transmission electron microscope was converted from analog (aTEM to digital processing (dTEM, and further to remote-access internet electron microscopy (iTEM. Lactobacillus acidophilus produced fewer, but larger, lactomicroSel nanoparticles (200–350 nm than Lactobacillus casei (L. casei, which generated many, smaller lactomicroSel particles (85–200 nm and grains as a cloudy, less electrodense material. Streptococcus thermophilus cells generated selenoparticles (60–280 nm in a suicidic manner. The size determined in situ in lactic acid bacteria was significantly lower than those measured by scanning electron microscopy after the isolation of lactomicroSel particles obtained from lactobacilli (100–500 nm, but higher relative to those isolated from Streptococcus thermopilus (50–100 nm. These differences indicate that smaller lactomicroSel particles could be more toxic to the producing bacteria themselves and discrepancies in size could have implications with respect to the applications of selenium nanoparticles as prebiotics.

  7. Physical and chemical quality, biodiversity, and thermodynamic prediction of adhesion of bacterial isolates from a water purification system: a case study

    Directory of Open Access Journals (Sweden)

    Roberta Barbosa Teodoro Alves

    2017-06-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the quality of water purification system and identify the bacteria this system, predict bacterial adherence according to the hydrophobicity of these microorganisms and of the polypropylene distribution loop for purified water. The assessment of drinking water that supplies the purification system allowed good-quality physical, chemical, and microbiological specifications. The physicochemical specifications of the distributed purified water were approved, but the heterotrophic bacteria count was higher than allowed (>2 log CFU mL-1.The sanitation of the storage tank with chlorine decreased the number of bacteria adhered to the surface (4.34 cycles log. By sequencing of the 16SrDNA genes, six species of bacteria were identified. The contact angle was determined and polypropylene surface and all bacteria were considered to be hydrophilic, and adhesion was thermodynamically unfavorable. This case study showed the importance of monitoring the water quality in the purified water systems and the importance of sanitization with chemical agents. The count of heterotrophic bacteria on the polypropylene surface was consistent with the predicted thermodynamics results because the number of adhered cells reached approximate values of 5 log CFU cm-2.

  8. Overview of the purification of recombinant proteins.

    Science.gov (United States)

    Wingfield, Paul T

    2015-04-01

    When the first version of this unit was written in 1995, protein purification of recombinant proteins was based on a variety of standard chromatographic methods and approaches, many of which were described and mentioned throughout Current Protocols in Protein Science. In the interim, there has been a shift toward an almost universal usage of the affinity or fusion tag. This may not be the case for biotechnology manufacture where affinity tags can complicate producing proteins under regulatory conditions. Regardless of the protein expression system, questions are asked as to which and how many affinity tags to use, where to attach them in the protein, and whether to engineer a self-cleavage system or simply leave them on. We will briefly address some of these issues. Also, although this overview focuses on E.coli, protein expression and purification, other commonly used expression systems are mentioned and, apart from cell-breakage methods, protein purification methods and strategies are essentially the same. Copyright © 2015 John Wiley & Sons, Inc.

  9. Rotating Reverse-Osmosis for Water Purification

    Science.gov (United States)

    Lueptow, RIchard M.

    2004-01-01

    A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse- osmosis membranes are vulnerable to concentration polarization a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water. A rotating filter consists of a cylindrical porous microfilter rotating within a stationary concentric cylindrical outer shell (see figure). The aqueous suspension enters one end of the annulus between the inner and outer cylinders. Filtrate passes through the rotating cylindrical microfilter and is removed via a hollow shaft. The concentrated suspension is removed at the end of the annulus opposite the end where the suspension entered.

  10. A Scintillator Purification System for the Borexino Solar Neutrino Detector

    OpenAIRE

    Benziger, J.; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E.; Ianni, Aldo; Ianni, Andrea; Kidner, S.; Leung, M.

    2007-01-01

    Purification of the 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector was performed with a system that combined distillation, water extraction, gas stripping and filtration. The purification of the scintillator achieved unprecedented low backgrounds for the large scale liquid scintillation detector. This paper describes the principles of operation, design, construction and commissioning of the purification system, and reviews the require...

  11. INFLUENCE OF CULTIVATION CONDITIONS ON ANTIMICROBIAL PROPERTIES OF Nocardia vaccinii ІMV B-7405 SURFACTANTS

    Directory of Open Access Journals (Sweden)

    Т. P.

    2016-02-01

    Full Text Available The aim of the work was investigation of antimicrobial effect of Nocardia vaccinii ІMV B-7405 surfactants, synthesized in various culture conditions, against phytopathogenic bacteria of genera Pseudomonas, Xanthomonas, and Pectobacterium. The antimicrobial properties of surfactant were determined in suspension culture by Koch method and also by index of the minimum inhibitory concentration. Surfactants were extracted from supernatant of cultural liquid using mixture of chloroform and methanol (2: 1. It has been established that antimicrobial properties of surfactants depend on the nature of the carbon source in the medium (refined vegetable oil, as well as waste oil after frying potatoes and meat, glycerol, the duration of the cultivation (5 and 7 days, the degree of purification of the surfactants (the supernatant of cultural liquid, purified surfactants solution and the test culture type. The highest antimicrobial activity was exhibited by purified surfactants solutions synthesized by microorganisms on the waste oil after potato frying (decreased survival of pathogenic bacteria by 50–95%, and surfactants formed within 7 days of strain B-7405 ІMV cultivation on all test substrates (minimum inhibitory concentration 7–40 µg/mL, which is several times lower than the surfactant, synthesized for 5 days. These data are promising for the development of ecologically friendly biopreparations for the regulation of the number of phytopathogenic bacteria.

  12. Nanostructured Catalytic Reactors for Air Purification, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  13. Compressorless Gas Storage and Regenerative Hydrogen Purification, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Microwave regenerative sorption media gas storage/delivery techniques are proposed to address both compressed gas management and hydrogen purification requirements...

  14. Nanostructured Catalytic Reactors for Air Purification, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase II project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  15. Antibacterial Activities of Lactic Acid Bacteria Isolated from Selected ...

    African Journals Online (AJOL)

    Members of lactic acid bacteria (LAB) are known probiotics and have been reported to have antimicrobial properties. Although various researchers have documented the isolation of these bacteria from fruits and vegetables, studies on LAB associated with lettuce, cucumber and cabbage are limited and non-existing in ...

  16. Characterization of lactic acid bacteria from camel milk and their ...

    African Journals Online (AJOL)

    Proper selection and balance for starter culture is critical for the manufacture of fermented products of desirable texture and flavor. The objective of this study was to characterize lactic acid bacteria (LAB) from camel milk and elucidate their properties to use as a starter culture. Twenty-one lactic acid bacteria species were ...

  17. On the kinetic and allosteric regulatory properties of the ADP-glucose pyrophosphorylase from Rhodococcus jostii: An approach to evaluate glycogen metabolism in oleaginous bacteria

    Directory of Open Access Journals (Sweden)

    Antonela Estefanía Cereijo

    2016-06-01

    Full Text Available Rhodococcus spp. are oleaginous bacteria that accumulate glycogen during exponential growth. Despite the importance of these microorganisms in biotechnology, little is known about the regulation of carbon and energy storage, mainly the relationship between glycogen and triacilglycerols metabolisms. Herein we report the molecular cloning and heterologous expression of the gene coding for ADP-glucose pyrophosphorylase (EC 2.7.7.27 of Rhodococcus jostii, strain RHA1. The recombinant enzyme was purified to electrophoretic homogeneity to accurately characterize its oligomeric, kinetic and regulatory properties. The R. jostii ADP-glucose pyrophosphorylase is a homotetramer of 190 kDa exhibiting low basal activity to catalyze synthesis of ADP-glucose, which is markedly influenced by different allosteric effectors. Glucose-6P, mannose-6P, fructose-6P, ribose-5P and phosphoenolpyruvate were major activators; whereas NADPH and 6P-gluconate behaved as main inhibitors of the enzyme. The combination of glucose-6P and other effectors (activators or inhibitors showed a cross-talk effect suggesting that the different metabolites could orchestrate a fine regulation of ADP-glucose pyrophosphorylase in R. jostii. The enzyme exhibited some degree of affinity toward ATP, GTP, CTP, and other sugar 1P substrates. Remarkably, the use of glucosamine-1P was sensitive to allosteric activation. The relevance of the fine regulation of R. jostii ADP-glucose pyrophosphorylase is further analyzed in the framework of proteomic studies already determined for the bacterium. Results support a critical role for glycogen as a temporal reserve that provides a pool of carbon able of be re-routed to produce long-term storage of lipids under certain conditions.

  18. Purification of β-acetylglucosaminase and β-galactosidase from ram testis

    Science.gov (United States)

    Caygill, J. C.; Roston, Christine P. J.; Jevons, F. R.

    1966-01-01

    1. The presence of β-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of β-acetylglucosaminase (EC 3.2.1.30) and of β-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the β-acetylglucosaminase 35 times and for the β-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated. PMID:5949569

  19. Polysaccharides from Traditional Chinese Medicines: Extraction, Purification, Modification, and Biological Activity.

    Science.gov (United States)

    Chen, Yun; Yao, Fangke; Ming, Ke; Wang, Deyun; Hu, Yuanliang; Liu, Jiaguo

    2016-12-13

    Traditional Chinese Medicine (TCM) has been used to treat diseases in China for thousands of years. TCM compositions are complex, using as their various sources plants, animals, fungi, and minerals. Polysaccharides are one of the active and important ingredients of TCMs. Polysaccharides from TCMs exhibit a wide range of biological activities in terms of immunity- modifying, antiviral, anti-inflammatory, anti-oxidative, and anti-tumor properties. With their widespread biological activities, polysaccharides consistently attract scientist's interests, and the studies often concentrate on the extraction, purification, and biological activity of TCM polysaccharides. Currently, numerous studies have shown that the modification of polysaccharides can heighten or change the biological activities, which is a new angle of polysaccharide research. This review highlights the current knowledge of TCM polysaccharides, including their extraction, purification, modification, and biological activity, which will hopefully provide profound insights facilitating further research and development.

  20. The fecal bacteria

    Science.gov (United States)

    Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  1. Dense Medium Plasma Water Purification Reactor (DMP WaPR), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Dense Medium Plasma Water Purification Reactor offers significant improvements over existing water purification technologies used in Advanced Life Support...

  2. Purification and recycling of the waste water of a paper mill using mechanical pulp; Mekaanista massaa kaeyttaevaen paperitehtaan jaeteveden puhdistus ja uudelleenkaeyttoe - EKY 07

    Energy Technology Data Exchange (ETDEWEB)

    Mattelemaeki, R. [Enso Oyj, Imatra (Finland)

    1998-12-31

    The objective of the project was to study which levels of organic and inorganic substances could be obtained by treatment of waste waters of mechanical pulper and paper machine biologically and after that with solid matter removal. Another target was also to test the utilisation of the purified water in pulp and paper manufacture, and to study the properties of purified water. The three months test runs with PK 4 and TMP plant clarified waters were carried out using a pilot-scale plant, which also consisted of two serial aerobic bioreactors and a parallel anaerobic line as a reference. The solid matter was removed by chemical flocculation, flotation and sand filtration. The purification efficiencies of both waters were similar both in aerobic and anaerobic lines. The reduction of soluble COD in biological stage was about 75 % and that of the whole line about 85 %. The solid matter reduction was 60-70 %. Solid fines, including bacteria, could not be removed sufficiently from the water by flotation and sand filtration so the water cannot be recommended to be used to replace fresh water. Circulating water sheets were produced, and pulp washing tests, retention tests and microbiological tests were carried out in order to estimate the recyclability of the water. Minor lowering of whiteness of the sheets were observed when a part of the fresh water was replaced with recycled water. Microscopic analysis shoved that after the sand filter there were a lot of free bacteria in the water. Further research will be concentrated to recycling of purified water, e.g. To research on how the colour of the water effects on the quality of the product. (orig.)

  3. Improvement of Taihu water quality by the technology of immobilized nitrogen cycle bacteria

    International Nuclear Information System (INIS)

    Li Zhengkui; Zhang Weidong; Zhu Jiating; Pu Peimin; Hu Weipin; Hu Chunhua; Chen Baojun; Li Bo; Cheng Xiaoying; Zhang Shengzhao; Fan Yunqi

    2002-01-01

    Experimental studies were carried out on the purification of eutrophic Taihu Lake water by dynamic experiment using immobilized nitrogen cycle bacteria (INCB). The results showed that the eutrophic water of Taihu Lake can be purified effectively as it passes through the experimental reactor into which some immobilized nitrogen cycle bacteria were put. The removal efficiencies for Total N (TN), NH 4 + -N with immobilized nitrogen cycle bacteria were 72.4% and 85.6%, respectively. It was found that the immobilized nitrogen cycle bacteria also have purificatory effect on eutrophic water of Taihu Lake at winter temperature (7 degree C), and that the removal efficiencies for Total N (TN), NH 4 + -N were 55.6%, and 58.9%, respectively. The removal efficiencies for TN and NH 4 + -N depend on the time the water stays in the experimental reactor

  4. ISOLATION OF OBLIGATELY ANAEROBIC PSYCHROPHILIC BACTERIA.

    Science.gov (United States)

    SINCLAIR, N A; STOKES, J L

    1964-03-01

    Sinclair, N. A. (Washington State University, Pullman), and J. L. Stokes. Isolation of obligately anaerobic psychrophilic bacteria. J. Bacteriol. 87:562-565. 1964.-A total of 11 strains of strictly anaerobic psychrophilic bacteria have been isolated from soil, mud, and sewage. The organisms grow well at 0 C in liquid and on solid media, and grow only in the complete absence of oxygen. On the basis of shape, sporulation, flagellation, and strictly anaerobic growth, all of the organisms were classified as strains of Clostridium. Some of the biochemical properties of the strains and the effect of temperature on growth are described.

  5. Purification and some kinetic properties of b- glucosidase from ...

    African Journals Online (AJOL)

    An intracellular b-glucosidase (EC 3.2.1.21) from Aspergillus terreus NRRL 265 grown on whey permeate was purified to homogeneity as indicated by disc acrylamide gel electrophoresis with an apparent molecular mass of about 116 kDa. Optimal activity was observed at pH 5.0 and 60°C. The b- glucosidase had Km ...

  6. Partial purification and properties of thiaminokinase from yeast

    NARCIS (Netherlands)

    Steyn-Parvé, Elizabeth P.

    1952-01-01

    Thiaminokinase, the enzyme catalyzing the synthesis of thiaminepyrophosphate from thiamine and adenosinetriphosphate, has been extracted from fresh bakers' yeast by plasmolysis by freezing at -70°C and thawing, followed by maceration at 37° in 0.5 M KCl. The enzyme has been partially purified

  7. Purification and Properties of Catalase from Sweet Potato Root Microbodies

    OpenAIRE

    Muneharu, Esaka; Tadashi, Asahi; Laboratory of Biochelnistry, Faculty of Agriculture, Nagoya University; Laboratory of Biochelnistry, Faculty of Agriculture, Nagoya University

    1982-01-01

    Catalase was isolated in a pure form from sweet potato root microbodies by simple procedures including ammonium sulfate fractionation and Sepharose 6B column chromatography. A single protein band was detected after polyacrylamide gel electrophoresis of the purified preparation. The catalase consisted of polypeptides with a molecular weight of 60,000 when analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis, while the molecular weight of the enzyme was about 240,000 when estima...

  8. Purification, product characterization and kinetic properties of soluble tomato lipoxygenase

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Suurmeijer, C.N.S.P.; Pérez-Gilabert, M.; Hijden, H.T.W.M. van der; Veldink, G.A.

    1998-01-01

    Soluble lipoxygenase (EC 1.13.11.12) from tomato fruits (Lycopersicon esculentum, var. Trust) was purified to apparent homogeneity as judged by SDS-PAGE, and the products and kinetics of the enzyme were studied in order to clarify the contradictory results that were obtained with a less purified

  9. Purification and Properties of Soluble Chlorophyllase from Tea Leaf Sprouts

    OpenAIRE

    Mioko, Kuroki; Yuzo, Shioi; Tsutomu, Sasa; Division of Biology. Mlyazaki Medical College; Division of Biology. Mlyazaki Medical College; Division of Biology. Mlyazaki Medical College

    1981-01-01

    Soluble chlorophyllase (chlorophyll-chlorophyllido-hydrolase, EC 3.1.1.14) was purified 650-fold from tea leafsprouts by ammonium sulfate fractionation and gel filtration through Sephadex G-200 and Sepharose CL-6B. The purified enzyme showed two bands on polyacrylamide gel electrophoresis and the specific activity was 2.6μmol chlorophyll a hydrolyzed min^ mg^ of protein. The molecular weights determined by Sepharose CL-6B were 910,000 and 350,000, indicating high molecular aggregates. The sub...

  10. Isolation, purification and properties of lipase from Pseudomonas ...

    African Journals Online (AJOL)

    Six isolates (Ps1, Ps2, Ps3, Ps4, Ps5 and Ps6) producing lipase were screened from wastewater on a selective medium agar containing Tween 80 or olive oil as the only source of carbon. Isolate Ps5 showed the highest lipase activity which was later identified as Pseudomonas aeruginosa. The effect of media composition ...

  11. Purification and Some Properties of Rubber Seed Lipoxygenase ...

    African Journals Online (AJOL)

    ... 49,000 and 107,000 daltons. The rubber seed lipoxygenase had two ionizing groups at the pK values of 4.8 and 7.3. It also had pK values of 5.2 and 7.5 as the ionization constants of the free enzyme. The activation energy (Ea) of the rubber seed lipoxygenase was 7.2 kcal/mole and the enthalpy (DH) was 5.3 kcal/mole.

  12. Purification and properties of a new dehalogenase enzyme from ...

    African Journals Online (AJOL)

    Halogenated compounds are widely used in agriculture and industries and have been associated with environmental pollution. Degradation of 3-chloropropionate (3CP) by microorganism has been established and this enzyme could only remove halogen atom at the â- position of 3-carbon alkanoic acids. Pseudomonas sp ...

  13. The purification and some properties of rhodanese from tortoise ...

    African Journals Online (AJOL)

    Rhodanese (cyanide: thiosulphate sulphur transferase; EC.2.8.1.1) was isolated from cytosolic fraction of tortoise liver using ammonium sulphate fractionation, ion exchange chromatography and gel filtration from the liver of tortoise. The enzyme had a specific activity of 14.43 RU per milligram of protein. The Km values for ...

  14. Purification and biochemical properties of a new thermostable ...

    African Journals Online (AJOL)

    The enzyme was stable for a long time-period up to 50°C and for 1 h at 60°C. Although the xylanase had a lower carboxymethylcellulase activity, it lacked activity towards substituted xylan, xylobiose, inulin, starch, polygalacturonic acid or pNP glycosides. Kinetic parameters indicated higher efficiency in the hydrolysis of ...

  15. Purification and Properties of Clostridium perfringens Spore Lytic Enzymes.

    Science.gov (United States)

    1983-01-01

    reaction mixture at 550C gave the opti- mum response although the activity of initiation protein remained high at 65"C and 75"C. Denaturation of the...CASSIER M. and Sebald M. 1969. Germination Iysozyme-ddpendente des spores de aCnerilim perfringeno ATCC 3624 sprks tralitment thermique . Ann. Inst. Pasteur...activity upon prolonged extraction -of spores in GME was not surprising, since this compound is an active protein denaturant . Urea acts in the same

  16. Purification and properties of a new dehalogenase enzyme from ...

    African Journals Online (AJOL)

    user

    2011-01-24

    Jan 24, 2011 ... Methylobacterium sp. HJ1. Afr. J. Microbiol. Res. 2: 187-191. Laemmli UK (1970). Cleavage of structural proteins during assembly of head of bacteriophage T4. Nature, 227: 680-685. Mesri S, Wahab RAB, Huyop F (2009). Degradation of 3- chloropropionic acid by Pseudomonas sp. B6P isolated from a rice.

  17. Carbon nanotubes: properties, synthesis, purification, and medical applications

    Science.gov (United States)

    2014-01-01

    Current discoveries of different forms of carbon nanostructures have motivated research on their applications in various fields. They hold promise for applications in medicine, gene, and drug delivery areas. Many different production methods for carbon nanotubes (CNTs) have been introduced; functionalization, filling, doping, and chemical modification have been achieved, and characterization, separation, and manipulation of individual CNTs are now possible. Parameters such as structure, surface area, surface charge, size distribution, surface chemistry, and agglomeration state as well as purity of the samples have considerable impact on the reactivity of carbon nanotubes. Otherwise, the strength and flexibility of carbon nanotubes make them of potential use in controlling other nanoscale structures, which suggests they will have a significant role in nanotechnology engineering. PMID:25170330

  18. Purification and properties of the dihydrofolate synthetase from Serratia indica

    International Nuclear Information System (INIS)

    Ikeda, Masamichi; Iwai, Kazuo

    1976-01-01

    The dihydrofolate synthetase (EC6.3.2.12) responsible for catalyzing the synthesis of dihydrofolic acid from dihydropteroic acid and L-glutamic acid was purified about 130-fold from extracts of Serratia indica IFO 3759 by ammonium sulfate fractionation, DEAE-Sephadex column chromatography, Sephadex G-200 gel filtration, and DEAE-cellulose column chromatography. The enzyme preparation obtained was shown to be homogeneous by DEAE-cellulose column chromatography and ultracentrifugal analysis. The sedimentation coefficient of this enzyme was 3.9 S, and the molecular weight was determined to be about 47,000 by Sephadex G-100. The optimum pH for the reaction was 9.0. The enzymatic reaction required dihydropteroate, L-glutamate and ATP as substrates, and Mg 2+ and K + as cofactors. γ-L-Glutamyl-L-glutamic acid cannot replace L-glutamic acid as the substrate. Neither pteroic acid nor tetrahydropteroic acid can be used as the substrate. ATP was partially replaced by ITP or GTP. The enzyme reaction was inhibited by the addition of ADP, but not by AMP. One mole of dihydrofolate, 1 mole of ADP and 1 mole of orthophosphate were produced from each 1 mole of dihydropteroic acid, L-glutamic acid, and ATP. These results suggest that the systematic name for the dihydrofolate synthetase is 7,8-dihydropteroate: L-glutamate ligase (ADP). (auth.)

  19. Isolation, Purification, and Some Properties of Penicillium chrysogenum Tannase.

    Science.gov (United States)

    Rajakumar, G S; Nandy, S C

    1983-08-01

    Tannase isolated from Penicillium chrysogenum was purified 24-fold with 18.5% recovery after ammonium sulfate precipitation, DEAE-cellulose column chromatography, and Sephadex G-200 gel filtration. Optimum enzyme activity was recorded at pH 5.0 to 6.0 and at 30 to 40 degrees C. The enzyme was stable up to 30 degrees C and within the pH range of 4.0 to 6.5. The K(m) value was found to be 0.48 x 10 M when tannic acid was used as the substrate. Metal salts at 20 mM inhibited the enzyme to different levels.

  20. Isolation, Purification, and Some Properties of Penicillium chrysogenum Tannase

    OpenAIRE

    Rajakumar, G. Suseela; Nandy, S. C.

    1983-01-01

    Tannase isolated from Penicillium chrysogenum was purified 24-fold with 18.5% recovery after ammonium sulfate precipitation, DEAE-cellulose column chromatography, and Sephadex G-200 gel filtration. Optimum enzyme activity was recorded at pH 5.0 to 6.0 and at 30 to 40°C. The enzyme was stable up to 30°C and within the pH range of 4.0 to 6.5. The Km value was found to be 0.48 × 10−4 M when tannic acid was used as the substrate. Metal salts at 20 mM inhibited the enzyme to different levels.

  1. Improved production, purification and some properties of α-amylase ...

    African Journals Online (AJOL)

    user

    2012-10-04

    Oct 4, 2012 ... 1Department of Natural Products / Microbiology and Biotechnology, Faculty of Pharmacy, King Abdulaziz University,. Jeddah ... starch medium by decreasing the concentration of soluble starch to 1%, increasing the corn steep liquor to .... activity were pooled and again applied on DEAE-cellulose column.

  2. Purification and properties of beta-galactosidase from Aspergillus nidulans.

    Science.gov (United States)

    Díaz, M; Pedregosa, A M; de Lucas, J R; Torralba, S; Monistrol, I F; Laborda, F

    1996-12-01

    Beta-Galactosidase from mycelial extract of Aspergillus nidulans has been purified by substrate affinity chromatography and used to obtain anti-beta-galactosidase polyclonal antibodies. A. nidulans growing in lactose as carbon source synthesizes one active form of beta-galactosidase which seems to be a multimeric enzyme of 450 kDa composed of monomers with 120 and 97 kDa. Although the enzyme was not released to the culture medium, some enzymatic activity was detected in a cell-wall extract, thus suggesting that it can be an extracellular enzyme. Beta-Galactosidase of A. nidulans is a very unstable enzyme with an optimum pH value of 7.5 and an optimum temperature of 30 degrees C. It was only active against beta-galactoside substrates like lactose and p-nitrophenyl-beta-D-galactoside (PNPG).

  3. Biotechnological potential of Clostridium butyricum bacteria

    Directory of Open Access Journals (Sweden)

    Daria Szymanowska-Powałowska

    2014-09-01

    Full Text Available In response to demand from industry for microorganisms with auspicious biotechnological potential, a worldwide interest has developed in bacteria and fungi isolation. Microorganisms of interesting metabolic properties include non-pathogenic bacteria of the genus Clostridium, particularly C. acetobutylicum, C. butyricum and C. pasteurianum. A well-known property of C. butyricum is their ability to produce butyric acid, as well as effectively convert glycerol to 1,3-propanediol (38.2 g/L. A conversion rate of 0.66 mol 1,3-propanediol/mol of glycerol has been obtained. Results of the studies described in the present paper broaden our knowledge of characteristic features of C. butyricum specific isolates in terms of their phylogenetic affiliation, fermentation capacity and antibacterial properties.

  4. In Situ Detection, Isolation, and Physiological Properties of a Thin Filamentous Microorganism Abundant in Methanogenic Granular Sludges: a Novel Isolate Affiliated with a Clone Cluster, the Green Non-Sulfur Bacteria, Subdivision I

    OpenAIRE

    Sekiguchi, Yuji; Takahashi, Hiroki; Kamagata, Yoichi; Ohashi, Akiyoshi; Harada, Hideki

    2001-01-01

    We previously showed that very thin filamentous bacteria affiliated with the division green non-sulfur bacteria were abundant in the outermost layer of thermophilic methanogenic sludge granules fed with sucrose and several low-molecular-weight fatty acids (Y. Sekiguchi, Y. Kamagata, K. Nakamura, A. Ohashi, H. Harada, Appl. Environ. Microbiol. 65:1280–1288, 1999). Further 16S ribosomal DNA (rDNA) cloning-based analysis revealed that the microbes were classified within a unique clade, green non...

  5. Efficient and versatile one-step affinity purification of in vivo biotinylated proteins: Expression, characterization and structure analysis of recombinant human glutamate carboxypeptidase II

    Energy Technology Data Exchange (ETDEWEB)

    Tykvart, J.; Sacha, P.; Barinka, C.; Knedlik, T.; Starkova, J.; Lubkowski, J.; Konvalinka, J. (Gilead); (NCI); (Czech Academy)

    2012-02-07

    Affinity purification is a useful approach for purification of recombinant proteins. Eukaryotic expression systems have become more frequently used at the expense of prokaryotic systems since they afford recombinant eukaryotic proteins with post-translational modifications similar or identical to the native ones. Here, we present a one-step affinity purification set-up suitable for the purification of secreted proteins. The set-up is based on the interaction between biotin and mutated streptavidin. Drosophila Schneider 2 cells are chosen as the expression host, and a biotin acceptor peptide is used as an affinity tag. This tag is biotinylated by Escherichia coli biotin-protein ligase in vivo. We determined that localization of the ligase within the ER led to the most effective in vivo biotinylation of the secreted proteins. We optimized a protocol for large-scale expression and purification of AviTEV-tagged recombinant human glutamate carboxypeptidase II (Avi-GCPII) with milligram yields per liter of culture. We also determined the 3D structure of Avi-GCPII by X-ray crystallography and compared the enzymatic characteristics of the protein to those of its non-tagged variant. These experiments confirmed that AviTEV tag does not affect the biophysical properties of its fused partner. Purification approach, developed here, provides not only a sufficient amount of highly homogenous protein but also specifically and effectively biotinylates a target protein and thus enables its subsequent visualization or immobilization.

  6. Mycorrhiza helper bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Labbe, Jessy [ORNL

    2016-10-01

    This chapter focuses on the Mycorrhiza Helper Bacteria (MHB), a generic name given to bacteria which stimulate the formation of mycorrhizal symbiosis. By extension, some bacterial strains that positively impact the functioning of mycorrhizal symbiosis are also called MHB. These bacteria have applicative interests, as they indirectly improve the health and growth of tree seedlings. MHB are not restricted to a specific type of ecosystem, but are rather generalist in the way that they associate with both herbaceous and woody mycorrhizal plants from boreal, temperate, arid and tropical ecosystems. However, understanding the molecular mechanisms and their specificities will help us to know more about the ecology of the MHB. The process of acquisition varies between fungal species; while ectomycorrhizal fungi most probably recurrently acquire them from the environment, the association between bacterial endosymbionts and Glomeromycota probably dates back to very ancient times, and has since been vertically transmitted.

  7. A scintillator purification system for the Borexino solar neutrino detector

    Energy Technology Data Exchange (ETDEWEB)

    Benziger, J. [Chemical Engineering Department, Princeton University, Princeton, NJ 08544 (United States)], E-mail: benziger@princeton.edu; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C. [Physics Department, Princeton University, Princeton, NJ 08544 (United States); Goretti, A. [INFN, Laboratori Nazionale di Gran Sasso (Italy); Harding, E. [Physics Department, Princeton University, Princeton, NJ 08544 (United States); Ianni, Aldo [INFN, Laboratori Nazionale di Gran Sasso (Italy); Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A. [Physics Department, Princeton University, Princeton, NJ 08544 (United States)] (and others)

    2008-03-21

    Purification of the 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system that combines distillation, water extraction, gas stripping, and filtration. This paper describes the principles of operation, design, and construction of that purification system, and reviews the requirements and methods to achieve system cleanliness and leak-tightness.

  8. Purification and Characterization of Lipase from Aspergillus flavus ...

    African Journals Online (AJOL)

    USER

    Abstract. Lipase from Aspergillus flavus was purified in a single step purification using MnFeO4 magnetic nano particles to achieve a 20.53- fold purification with specific activity of. 11.29 U/mg and a 59% recovery yield. SDS-PAGE of lipase showed a single pure band with corresponding molecular weight of 35 kDa.

  9. A scintillator purification system for the Borexino solar neutrino detector

    Science.gov (United States)

    Benziger, J.; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E.; Ianni, Aldo; Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A.; Salvo, C.; Schimizzi, D.; Shutt, T.; Sonnenschein, A.

    2008-03-01

    Purification of the 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system that combines distillation, water extraction, gas stripping, and filtration. This paper describes the principles of operation, design, and construction of that purification system, and reviews the requirements and methods to achieve system cleanliness and leak-tightness.

  10. New Combined Electron-Beam Methods of Wastewater Purification

    International Nuclear Information System (INIS)

    Pikaev, A.K.; Makarov, I.E.; Ponomarev, A.V.; Kartasheva, L.I.; Podzorova, E.A.; Chulkov, V.N.; Han, B.; Kim, D.K.

    1999-01-01

    The paper is a brief review of the results obtained with the participation of the authors from the study on combined electron-beam methods for purification of some wastewaters. The data on purification of wastewaters containing dyes or hydrogen peroxide and municipal wastewater in the aerosol flow are considered

  11. Comparative study of peroxidase purification from apple and orange ...

    African Journals Online (AJOL)

    This paper reports the isolation and purification of peroxidase from low cost material; moreover, no significant work has been done on the isolation and purification of peroxidase from such cost effective sources (apple and orange seeds). Peroxidases had attracted considerable interest in recent years because of their ...

  12. Overview of the recombinant proteins purification by affinity tags and ...

    African Journals Online (AJOL)

    From protein within isolation process which the same matter increases labor costs further and prevents application of these tags in industrial scale. Therefore proper replacement is emphasized for enzymatic removal of purification tags. Keywords: protein purification; recombinant proteins; self-cleavable tags; Intein tags; ...

  13. Effect of Purification Procedures on DIF Analysis in IRTPRO

    Science.gov (United States)

    Fikis, David R. J.; Oshima, T. C.

    2017-01-01

    Purification of the test has been a well-accepted procedure in enhancing the performance of tests for differential item functioning (DIF). As defined by Lord, purification requires reestimation of ability parameters after removing DIF items before conducting the final DIF analysis. IRTPRO 3 is a recently updated program for analyses in item…

  14. Purification of cadmium up to 5N+ by vacuum distillation

    Indian Academy of Sciences (India)

    Unknown

    Other areas of applications include telecommunications, electric vehicle and remote area storage systems. The problem connected with profound purification and characterization of the materials that are used for the synthesis of electronic materials remains critical. The advantage of methods providing efficient purification.

  15. Optimization of laboratory scale production and purification of ...

    African Journals Online (AJOL)

    Microcystin content is however highly variable and optimised culture conditions are essential to produce viable yields of microcystin for purification. We describe the optimization of culture conditions and evaluation of various purification methods to enhance the yield of microcystin from laboratory scale culture.

  16. New matrices for the purification of pectinases by affinity chromatography.

    Science.gov (United States)

    Lobarzewski, J; Fiedurek, J; Ginalska, G; Wolski, T

    1985-09-16

    Polygalacturonic acid was used as a ligand in the affinity technique for pectinases purification from the filtrate of Aspergillus niger 71 culture. For this purpose four matrices were examined, namely, alkylamine controlled porous glass (CPG), alkylamine silica gel as well as keratin or polyamide coated silica gel. Good results of pectinase purification was obtained on silanized CPG or keratin coated silica gel supports.

  17. Necessity of purification during bacterial DNA extraction with environmental soils

    Directory of Open Access Journals (Sweden)

    Hyun Jeong Lim

    2017-08-01

    Full Text Available Complexity and heterogeneity of soil samples have often implied the inclusion of purification steps in conventional DNA extraction for polymerase chain reaction (PCR assays. Unfortunately the purification steps are also time and labor intensive. Therefore the necessity of DNA purification was re-visited and investigated for a variety of environmental soil samples that contained various amounts of PCR inhibitors. Bead beating and centrifugation was used as the baseline (without purification method for DNA extraction. Its performance was compared with that of conventional DNA extraction kit (with purification. The necessity criteria for DNA purification were established with environmental soil samples. Using lysis conditions at 3000 rpm for 3 minutes with 0.1 mm glass beads, centrifugation time of 10 minutes and 1:10 dilution ratio, the baseline method outperformed conventional DNA extraction on cell seeded sand samples. Further investigation with PCR inhibitors (i.e., humic acids, clay, and magnesium [Mg] showed that sand samples containing less than 10 μg/g humic acids and 70% clay may not require purifications. Interestingly, the inhibition pattern of Mg ion was different from other inhibitors due to the complexation interaction of Mg ion with DNA fragments. It was concluded that DNA extraction method without purification is suitable for soil samples that have less than 10 μg/g of humic acids, less than 70% clay content and less than 0.01% Mg ion content.

  18. Purification and characterization of a protease from Thermophilic ...

    African Journals Online (AJOL)

    The purification and characterization of a thermophilic neutral protease from Thermophilic bacillus strain HS08, originally isolated from a soil sample collected from the Tulufan Crater of China, is presented in this paper. The purification steps included ammonium sulfate precipitation, with columns of DEAE-Sepharose anion ...

  19. Purification and characterization of a novel extracellular chitinase ...

    African Journals Online (AJOL)

    The purification and characterization of a new thermophilic chitinase from thermophilic Bacillus sp. HU1, originally isolated from a soil sample collected from hot spring of XinJiang Province, China, is presented in this paper. The purification steps included ammonium sulfate precipitation, with columns of DEAE-Sepharose ...

  20. Purification and fluorescent labeling of the human serotonin transporter

    DEFF Research Database (Denmark)

    Rasmussen, Søren G F; Gether, Ulrik

    2005-01-01

    To establish a purification procedure for the human serotonin transporter (hSERT) we expressed in Sf9 insect cells an epitope-tagged version of the transporter containing a FLAG epitope at the N-terminus and a polyhistidine tail at the C-terminus (FLAG-hSERT-12H). For purification, the transporter...

  1. One-step purification of E. coli elongation factor Tu

    DEFF Research Database (Denmark)

    Knudsen, Charlotte Rohde; Clark, Brian F. C.; Degn, B

    1993-01-01

    The tuf A gene, encoding the E. coli elongation factor Tu, was cloned in the pGEX gene fusion system. Upon expression EF-Tu is fused to glutathione-S-transferase serving as a purification handle with affinity for glutathione immobilised on agarose. This allows purification of EF-Tu in a one...

  2. Ribonucleoprotein purification and characterization using RNA Mango.

    Science.gov (United States)

    Panchapakesan, Shanker Shyam S; Ferguson, Matthew L; Hayden, Eric J; Chen, Xin; Hoskins, Aaron A; Unrau, Peter J

    2017-10-01

    The characterization of RNA-protein complexes (RNPs) is a difficult but increasingly important problem in modern biology. By combining the compact RNA Mango aptamer with a fluorogenic thiazole orange desthiobiotin (TO1-Dtb or TO3-Dtb) ligand, we have created an RNA tagging system that simplifies the purification and subsequent characterization of endogenous RNPs. Mango-tagged RNP complexes can be immobilized on a streptavidin solid support and recovered in their native state by the addition of free biotin. Furthermore, Mango-based RNP purification can be adapted to different scales of RNP isolation ranging from pull-down assays to the isolation of large amounts of biochemically defined cellular RNPs. We have incorporated the Mango aptamer into the S. cerevisiae U1 small nuclear RNA (snRNA), shown that the Mango-snRNA is functional in cells, and used the aptamer to pull down a U1 snRNA-associated protein. To demonstrate large-scale isolation of RNPs, we purified and characterized bacterial RNA polymerase holoenzyme (HE) in complex with a Mango-containing 6S RNA. We were able to use the combination of a red-shifted TO3-Dtb ligand and eGFP-tagged HE to follow the binding and release of the 6S RNA by two-color native gel analysis as well as by single-molecule fluorescence cross-correlation spectroscopy. Together these experiments demonstrate how the Mango aptamer in conjunction with simple derivatives of its flurophore ligands enables the purification and characterization of endogenous cellular RNPs in vitro. © 2017 Panchapakesan et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  3. Physiological and metagenomic analyses of microbial mats involved in self-purification of mine waters contaminated with heavy metals

    Directory of Open Access Journals (Sweden)

    Lukasz Drewniak

    2016-08-01

    Full Text Available Two microbial mats found inside two old (gold and uranium mines in Zloty Stok and Kowary located in SW Poland seem to form a natural barrier that traps heavy metals leaking from dewatering systems. We performed complex physiological and metagenomic analyses to determine which microorganisms are the main driving agents responsible for self-purification of the mine waters and identify metabolic processes responsible for the observed features. SEM and energy dispersive X-ray microanalysis showed accumulation of heavy metals on the mat surface, whereas, sorption experiments showed that neither microbial mats were completely saturated with heavy metals present in the mine waters, indicating that they have a large potential to absorb significant quantities of metal. The metagenomic analysis revealed that Methylococcaceae and Methylophilaceae families were the most abundant in both communities, moreover, it strongly suggest that backbones of both mats were formed by filamentous bacteria, such as Leptothrix, Thiothrix, and Beggiatoa. The Kowary bacterial community was enriched with the Helicobacteraceae family, whereas the Zloty Stok community consist mainly of Sphingomonadaceae, Rhodobacteraceae, and Caulobacteraceae families. Functional (culture-based and metagenome (sequence-based analyses showed that bacteria involved in immobilization of heavy metals, rather than those engaged in mobilization, were the main driving force within the analyzed communities. In turn, a comparison of functional genes revealed that the biofilm formation and heavy metal resistance functions are more desirable in microorganisms engaged in water purification than the ability to utilize heavy metals in the respiratory process (oxidation-reduction. These findings provide insight on the activity of bacteria leading, from biofilm formation to self-purification, of mine waters contaminated with heavy metals

  4. Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

    International Nuclear Information System (INIS)

    Dolmatov, Valerii Yu

    2007-01-01

    The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

  5. Biopharmaceuticals from microorganisms: from production to purification

    Directory of Open Access Journals (Sweden)

    Angela Faustino Jozala

    Full Text Available ABSTRACT The use of biopharmaceuticals dates from the 19th century and within 5-10 years, up to 50% of all drugs in development will be biopharmaceuticals. In the 1980s, the biopharmaceutical industry experienced a significant growth in the production and approval of recombinant proteins such as interferons (IFN α, β, and γ and growth hormones. The production of biopharmaceuticals, known as bioprocess, involves a wide range of techniques. In this review, we discuss the technology involved in the bioprocess and describe the available strategies and main advances in microbial fermentation and purification process to obtain biopharmaceuticals.

  6. Phase equilibria at the Zirconium metal purification

    International Nuclear Information System (INIS)

    Dwiretnani-Sudjoko; Busron-Masduki; Sunardjo; Budi-Sulistyo

    1996-01-01

    It was investigated the research in the purification of zirconium metal, which was results from the reduction process, by adding heat in the vacuum environment. The process was done in batch in the stainless steel reactor, equiped with vacuum pump and electric heater. The investigated variable were process temperature and pressure. From this research it was obtained that equilibrium constant for MgCl 2 and Mg were expressed in the equation K M g C l 2 = 0.9011 P 1 .3779 1.06552 T and K M g = 6.0115P + 1.35256T - 6.93912

  7. Purification of Argon from a Diluted Stream

    Energy Technology Data Exchange (ETDEWEB)

    Montanari, D. [Princeton U.; Alton, A.; Back, H. O. [Fermilab; Davis, R. P. [Fermilab; Galbiati, C. [Princeton U.; Hardin, K. L. [Fermilab; Jaskierny, W. F. [Fermilab; Kendziora, C. L. [Fermilab; Loer, B. [Princeton U.; Miner, W. E. [Fermilab; Mosteiro, P. J. [Princeton U.; Pordes, S. H. [Fermilab; Subbarao, P. [Princeton U.

    2012-07-23

    We report on the design, performance and commissioning of a cryogenic distillation column for low radioactivity underground argon purification that has been constructed at Fermi National Accelerator Laboratory. The plant accepts a mixture of argon, helium, and nitrogen with low argon concentration and is designed to return pure argon with a nitrogen contamination less than 10 ppm. During the commissioning, the distillation column in a continuous mode produced argon 99.9% pure. After running in batch mode, the argon purity was increased to 99.95%, with 500 ppm of nitrogen remaining. The argon production rate was about 1 kg/day.

  8. RNA purification by preparative polyacrylamide gel electrophoresis.

    Science.gov (United States)

    Petrov, Alexey; Wu, Tinghe; Puglisi, Elisabetta Viani; Puglisi, Joseph D

    2013-01-01

    Preparative polyacrylamide gel electrophoresis (PAGE) is a powerful tool for purifying RNA samples. Denaturing PAGE allows separation of nucleic acids that differ by a single nucleotide in length. It is commonly used to separate and purify RNA species after in vitro transcription, to purify naturally occurring RNA variants such as tRNAs, to remove degradation products, and to purify labeled RNA species. To preserve RNA integrity following purification, RNA is usually visualized by UV shadowing or stained with ethidium bromide or SYBR green dyes. © 2013 Elsevier Inc. All rights reserved.

  9. Radionuclide characterization of spent purification filters

    International Nuclear Information System (INIS)

    Sinclair, A.N.; Spooner, P.

    1984-01-01

    A remote handling facility is described which will aid in the assessment of the radionuclide mix and total activity content of spent purification filters. The facility will also dry filters as part of their preparation for off-site shipment. One possible system design, consisting of a robot with five degrees of freedom, a shielded Ge-Li detector, and a vacuum drying system, is described. Benefits could include reduced operating and waste storage or burial costs, feedback on filter performance, and an improved understanding of environmental protection requirements

  10. CAREM-25. Purification and volume control system

    International Nuclear Information System (INIS)

    Acosta, Eduardo; Carlevaris, Rodolfo; Patrignani, Alberto; Chocron, Mauricio; Goya, Hector E.; Ortega, Daniel A.; Ramilo, Lucia B.

    2000-01-01

    The purification and volume control system has the following main functions: water level control inside reactor pressure vessel (RPR) in all the reactor operational modes, pressure control when the reactor operates in solid state, and maintenance of radiological, physical and chemical parameters of primary water. In case of Hot Shutdown operational mode and also after Scram the system is capable of extraction of nuclear decay heat. The design of the system is in accordance with the Requirements of ANSI/ ANS 51.1; 58.11 and 56.2 standards. (author)

  11. Hydrodynamic interaction between bacteria and passive sphere

    Science.gov (United States)

    Zhang, Bokai; Ding, Yang; Xu, Xinliang

    2017-11-01

    Understanding hydrodynamic interaction between bacteria and passive sphere is important for identifying rheological properties of bacterial and colloidal suspension. Over the past few years, scientists mainly focused on bacterial influences on tracer particle diffusion or hydrodynamic capture of a bacteria around stationary boundary. Here, we use superposition of singularities and regularized method to study changes in bacterial swimming velocity and passive sphere diffusion, simultaneously. On this basis, we present a simple two-bead model that gives a unified interpretation of passive sphere diffusion and bacterial swimming. The model attributes both variation of passive sphere diffusion and changes of speed of bacteria to an effective mobility. Using the effective mobility of bacterial head and tail as an input function, the calculations are consistent with simulation results at a broad range of tracer diameters, incident angles and bacterial shapes.

  12. Bacteria in atmospheric waters: Detection, characteristics and implications

    Science.gov (United States)

    Hu, Wei; Niu, Hongya; Murata, Kotaro; Wu, Zhijun; Hu, Min; Kojima, Tomoko; Zhang, Daizhou

    2018-04-01

    In this review paper, we synthesize the current knowledges about bacteria in atmospheric waters, e.g., cloud, fog, rain, and snow, most of which were obtained very recently. First, we briefly describe the importance of bacteria in atmospheric waters, i.e., the essentiality of studying bacteria in atmospheric waters in understanding aerosol-cloud-precipitation-climate interactions in the Earth system. Next, approaches to collect atmospheric water samples for the detection of bacteria and methods to identify the bacteria are summarized and compared. Then the available data on the abundance, viability and community composition of bacteria in atmospheric waters are summarized. The average bacterial concentration in cloud water was usually on the order 104-105 cells mL-1, while that in precipitation on the order 103-104 cells mL-1. Most of the bacteria were viable or metabolically active. Their community composition was highly diverse and differed at various sites. Factors potentially influencing the bacteria, e.g., air pollution levels and sources, meteorological conditions, seasonal effect, and physicochemical properties of atmospheric waters, are described. After that, the implications of bacteria present in atmospheric waters, including their effect on nucleation in clouds, atmospheric chemistry, ecosystems and public health, are briefly discussed. Finally, based on the current knowledges on bacteria in atmospheric waters, which in fact remains largely unknown, we give perspectives that should be paid attention to in future studies.

  13. Antifreeze Proteins of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Antifreeze Proteins of Bacteria. M K Chattopadhyay. General Article Volume 12 Issue 12 December 2007 pp 25-30. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/012/12/0025-0030 ...

  14. (PHB)-producing bacteria

    African Journals Online (AJOL)

    Jane

    2011-06-06

    Jun 6, 2011 ... Bioplastics are naturally occurring biodegradable polymers made from polyhydroxyalkanoates (PHA) of which poly 3-hydroxy butyric acid ... The plastic polymers accumulate intracellularly as light- refracting amorphous ... study focuses on the isolation and identification of novel species of bacteria capable ...

  15. Do Bacteria Age?

    Indian Academy of Sciences (India)

    Bacteria are thought to be examples of organisms that do not age. ... sues, organs, organ systems, organism, population, species, and .... Humans inevitably grow old through aging. All vertebrates show physical manifestations of aging somewhat similar to humans (other than white hair!). Aging is also seen in plants.

  16. Antifreeze Proteins of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Antifreeze Proteins of Bacteria. M K Chattopadhyay. General Article Volume 12 Issue 12 December 2007 pp 25-30. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/012/12/0025-0030. Keywords.

  17. Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

    A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

  18. (PHB)-producing bacteria

    African Journals Online (AJOL)

    Isolation and characterization of two novel polyhydroxybutyrate (PHB)-producing bacteria. ... subsequently studied using phenotype microarray panels which allowed the testing of the effect of more than 90 different carbon, nitrogen, sulfur and phosphorus sources as well as pH on the growth characteristics of these strains.

  19. Affinity chromatography purification of angiotensin II reactor using photoactivable biotinylated probes

    Energy Technology Data Exchange (ETDEWEB)

    Marie, J.; Seyer, R.; Lombard, C.; Desarnaud, F.; Aumelas, A.; Jard, A.; Bonnafous, J.C. (Centre CNRS-INSERM de Pharmacologie-Endocrinologie, Montpellier (France))

    1990-09-25

    The authors have developed biotinylated photoactivable probes that are suitable for covalent labeling of angiotensin II (AII) receptors and the subsequent purification of covalent complexes through immobilized avidin or streptavidin. One of these probes, biotin-NH(CH{sub 2}){sub 2}SS(CH{sub 2}){sub 2}CO-(Ala{sup 1}, Phe(4N{sub 3}){sup 8})AII, which contains a cleavage disulfide bridge in its spacer arm and which displays, in its radioiodinated form, very high affinity for AII receptors (K{sub d}{approximately}1 nM), proved to be suitable for indirect affinity chromatography of rate liver receptor with facilitated recovery from avidin gels by use of reducing agents. This constituted the central step of an efficient partial purification scheme involving hydroxylapatite chromatography, streptavidin chromatography, and thiopropyl-Sepharose chromatography. SDS-PAGE analysis and autoradiography established the identity of the purified entity (molecular weight 65K) as the AII receptor. Possible ways of completing purification to homogeneity and extrapolation of the protocols to a preparative scale are discussed, as well as the potential contribution of our new probes to the study of the structural properties of angiotensin receptors.

  20. Novel purification method of human immunoglobulin by using a thermo-responsive protein A.

    Science.gov (United States)

    Koguma, Ichiro; Yamashita, Shuntaro; Sato, Satoshi; Okuyama, Kazuo; Katakura, Yoshinori

    2013-08-30

    We attempted to evaluate a novel purification method of immunoglobulins (IgGs) by using a mutant type of protein A. Although this mutant protein A binds to IgGs at 5°C, the IgGs are released at 40°C; hence, it was designated as thermo-responsive protein A (TRPA). We aimed to purify IgG1 from the culture supernatant of CHO cells producing AE6F4 human monoclonal IgG1. AE6F4 IgG1 was purified using only a TRPA-filled column and by modifying the temperature, without any exposure to acidic conditions. Furthermore, the purified AE6F4 IgG1 maintained the inherent binding affinity to antigen, while this property was lost in AE6F4 IgG1 purified using a conventional protein A (CPA) column possibly because of product aggregation and fragmentation. These data suggest that IgG is sensitive to acid treatment; however, it can be highly purified with retention of high affinity by using a TRPA column. Further, this purification method can be used on an industrial scale for the purification of antibody drugs. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Two novel solvent system compositions for protected synthetic peptide purification by centrifugal partition chromatography.

    Science.gov (United States)

    Amarouche, Nassima; Giraud, Matthieu; Forni, Luciano; Butte, Alessandro; Edwards, F; Borie, Nicolas; Renault, Jean-Hugues

    2014-04-11

    Protected synthetic peptide intermediates are often hydrophobic and not soluble in most common solvents. They are thus difficult to purify by preparative reversed-phase high-performance liquid chromatography (RP-HPLC), usually used for industrial production. It is then challenging to develop alternative chromatographic purification processes. Support-free liquid-liquid chromatographic techniques, including both hydrostatic (centrifugal partition chromatography or CPC) and hydrodynamic (counter-current chromatography or CCC) devices, are mainly involved in phytochemical studies but have also been applied to synthetic peptide purification. In this framework, two new biphasic solvent system compositions covering a wide range of polarity were developed to overcome solubility problems mentioned above. The new systems composed of heptane/tetrahydrofuran/acetonitrile/dimethylsulfoxide/water and heptane/methyl-tetrahydrofuran/N-methylpyrrolidone/water were efficiently used for the CPC purification of a 39-mer protected exenatide (Byetta®) and a 8-mer protected peptide intermediate of bivalirudin (Angiox®) synthesis. Phase compositions of the different biphasic solvent systems were determined by (1)H nuclear magnetic resonance. Physico-chemical properties including viscosity, density and interfacial tension of these biphasic systems are also described. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Inorganic membranes for hydrogen production and purification: a critical review and perspective.

    Science.gov (United States)

    Lu, G Q; Diniz da Costa, J C; Duke, M; Giessler, S; Socolow, R; Williams, R H; Kreutz, T

    2007-10-15

    Hydrogen as a high-quality and clean energy carrier has attracted renewed and ever-increasing attention around the world in recent years, mainly due to developments in fuel cells and environmental pressures including climate change issues. In thermochemical processes for hydrogen production from fossil fuels, separation and purification is a critical technology. Where water-gas shift reaction is involved for converting the carbon monoxide to hydrogen, membrane reactors show great promises for shifting the equilibrium. Membranes are also important to the subsequent purification of hydrogen. For hydrogen production and purification, there are generally two classes of membranes both being inorganic: dense phase metal and metal alloys, and porous ceramic membranes. Porous ceramic membranes are normally prepared by sol-gel or hydrothermal methods, and have high stability and durability in high temperature, harsh impurity and hydrothermal environments. In particular, microporous membranes show promises in water gas shift reaction at higher temperatures. In this article, we review the recent advances in both dense phase metal and porous ceramic membranes, and compare their separation properties and performance in membrane reactor systems. The preparation, characterization and permeation of the various membranes will be presented and discussed. We also aim to examine the critical issues in these membranes with respect to the technical and economical advantages and disadvantages. Discussions will also be made on the relevance and importance of membrane technology to the new generation of zero-emission power technologies.

  3. Protocol for Initial Purification of Bacteriocin

    Science.gov (United States)

    2015-10-01

    REPORT DATE (DD-MM-YYYY) 30-10-2015 2. REPORT TYPE Final 3. DATES COVERED (From - To) February 2013 – August 2014 4. TITLE AND SUBTITLE PROTOCOL...microorganisms. 3 5. Test Organisms  Target bacteria – Bacillus anthracis Sterne, Staphylococcus aureus ATCC 27217, or Pseudomonas aeruginosa...freezer. 6. Procedures 6.1. Prepare Target Bacteria:  Inoculate a single colony of a fresh culture of Bacillus anthracis Sterne, Staphylococcus

  4. Installation of the Tritium Purification System

    Energy Technology Data Exchange (ETDEWEB)

    Labik, G.; Golian, T.; Satkofsky, J.; Sichta, P.; Crook, D.; Dudek, L.; Coward, G.; Parsells, R. [Princeton Plasma Physics Lab., NJ (United States)

    1995-12-31

    This paper describes and details the design, the tasks, and the considerations for the mechanical and electrical installation of the TFTR Tritium Purification System (TPS) at the Princeton Plasma Physics Laboratory (PPPL). Canadian Fusion Fuels Technology Project (CFFTP) designed, fabricated, assembled and tested the Tritium Purification System in Ontario, Canada. After system tests were accepted by Princeton Plasma Physics Laboratory, the assembled components were disassembled into a set of subassemblies and were shipped to PPPL. The subassemblies were reassembled at PPPL and installed primarily in the Decon Facility. The original site selection was within the TFTR tritium processing area and that selection impacted the column design. The Decon Facility was later chosen to permit a better layout of equipment and improved access for installation personnel. Selection of the Decon Facility site resulted in longer line runs for most of the process streams including the tritium product line. The initial review of the proposed installation was conducted during September of 1994 and the System Integrated Test began during April 1995, subsequent to a successful Operational Readiness Assessment conducted during March of 1995.

  5. Carbohydrate-degrading bacteria closely associated with Tetraselmis indica: Influence on algal growth

    Digital Repository Service at National Institute of Oceanography (India)

    Arora, M.; Anil, A.C.; Delany, J.; Rajarajan, N.; Emami, K.; Mesbahi, E.

    (2003) Detachment of Actinobacillus actinomycetemcomitans biofilm cells by an endogenous beta-hexosaminidase activity. J. Bacteriol 185:4693-4698 Kathoda S, Suzuki F, Katsuki S, Sato T (1979) Purification and some properties of endo-β-1,6- glucanase...

  6. Water purification using porous ceramics prepared by recycling volcanic ash and waste glass

    Science.gov (United States)

    Ando, Tomohiro; Fujita, Yuki; Kakinaga, Mayu; Oka, Nobuto; Nishida, Tetsuaki

    2017-11-01

    Water purification was examined using porous ceramics prepared by sintering a powder mixture of volcanic ash, waste glass and a small amount of wood charcoal. The porous ceramics had cross-linked 3D-channels of which the diameter ranged from several nm to several μm. Three kilograms of porous ceramics placed in 90 L of circulating artificial seawater, in which several tropical fishes were actually living under aeration, caused a decrease in COD from 23.8 to 13.1 mg L-1 in a week. The number of coliform bacteria was almost constant in a range of 52-65 mL-1 despite that a lot of excrements were discharged frequently. The number of the coliform bacteria in the seawater examined "without the tropical fishes" decreased from 900 to 1 mL-1 in 2 weeks, and COD decreased from 37.9 to 7.9 mg L-1. It proved that several aerobic bacteria proliferating in the macropores inside the porous ceramics could effectively decompose several organic materials.

  7. Novel purification method and antibiotic activity of recombinant Momordica charantia MAP30.

    Science.gov (United States)

    Chang, Ching-Dong; Lin, Ping-Yuan; Chen, Yo-Chia; Huang, Han-Hsiang; Shih, Wen-Ling

    2017-05-01

    Ribosome-inactivating proteins (RIPs) are a group of enzymes originally isolated from plants that possess the ability to damage ribosomes in an irreversible manner, leading to inhibition of protein synthesis in eukaryotic cells. In this study, we aimed to purify recombinant RIPs, investigate their function in the treatment of bacterial infection, and determine their toxicity in mice. We employed a pMAL protein fusion and purification system using E. coli transformed with a plasmid containing MBP-tagged MAP30 cDNA. MBP-tagged MAP30 was purified using a modified novel protocol to effectively produce highly active MAP30 of high purity. In an acute toxicity study in mice, no mortality occurred at doses lower than 1.25 mg/kg. MAP30 at both 0.42 and 0.14 mg/kg induced anti-MAP30 IgG, which reached a maximum titer at week 3. In conclusion, recombinant MAP30 prepared using our purification method possesses bioactivity, and has a synergistic bacteria-killing effect that can significantly reduce the required dosages of chloramphenicol and erythromycin. Therefore, when MAP30 is used in combination with chloramphenicol or erythromycin, it may of benefit in terms of reducing the side effects of the antibiotics, as lower concentrations of antibiotics are required.

  8. The purification, crystallization and preliminary X-ray diffraction analysis of dihydrodipicolinate synthase from Clostridium botulinum

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Renwick C. J., E-mail: rdobson@unimelb.edu.au; Atkinson, Sarah C. [Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010 (Australia); Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, University of Melbourne, Parkville, Victoria 3010 (Australia); Gorman, Michael A. [St Vincents Institute, 9 Princes Street, Fitzroy, Victoria 3065 (Australia); Newman, Janet M. [CSIRO Division of Molecular and Health Technologies, 343 Royal Parade, Parkville, Victoria 3052 (Australia); Parker, Michael W. [Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010 (Australia); Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, University of Melbourne, Parkville, Victoria 3010 (Australia); St Vincents Institute, 9 Princes Street, Fitzroy, Victoria 3065 (Australia); Perugini, Matthew A. [Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010 (Australia); Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, University of Melbourne, Parkville, Victoria 3010 (Australia)

    2008-03-01

    Dihydrodipicolinate synthase (DHDPS), an enzyme in the lysine-biosynthetic pathway, is a promising target for antibiotic development against pathogenic bacteria. Here, the expression, purification, crystallization and preliminary diffraction analysis of DHDPS from C. botulinum are reported. In recent years, dihydrodipicolinate synthase (DHDPS; EC 4.2.1.52) has received considerable attention from both mechanistic and structural viewpoints. This enzyme, which is part of the diaminopimelate pathway leading to lysine, couples (S)-aspartate-β-semialdehyde with pyruvate via a Schiff base to a conserved active-site lysine. In this paper, the expression, purification, crystallization and preliminary X-ray diffraction analysis of DHDPS from Clostridium botulinum, an important bacterial pathogen, are presented. The enzyme was crystallized in a number of forms, predominantly using PEG precipitants, with the best crystal diffracting to beyond 1.9 Å resolution and displaying P4{sub 2}2{sub 1}2 symmetry. The unit-cell parameters were a = b = 92.9, c = 60.4 Å. The crystal volume per protein weight (V{sub M}) was 2.07 Å{sup 3} Da{sup −1}, with an estimated solvent content of 41%. The structure of the enzyme will help guide the design of novel therapeutics against the C. botulinum pathogen.

  9. Purification of recombinant tissue plasminogen activator (rtPA) protein from transplastomic tobacco plants.

    Science.gov (United States)

    Abdoli Nasab, Maryam; Jalali Javaran, Mokhtar; Cusido, Rosa M; Palazon, Javier

    2016-11-01

    Plants are low cost platforms for the production of recombinant proteins, but their complexity renders the purification of plant recombinant proteins more difficult than proteins expressed in yeast or bacteria. Plastid transformation enables high-level expression of foreign genes and the accumulation of recombinant proteins in plastid organelles. Histidine (His) tags are widely used for affinity purification of recombinant proteins in a nickel column. The human tissue-type plasminogen activator (tPA) is one of the most important pharmaceutical recombinant proteins involved in the breakdown of blood clots in different parts of the body. The truncated form of the tissue plasminogen activator (K2S) has a longer plasma half-life, better diffusion into the clot, and higher fibrinolytic activity. In a construct designed to insert the K2S gene in the tobacco chloroplast, the sequence of six histidines and a factor Xa protease site was fused to the C-terminus of the K2S protein. The presence and amount of tPA recombinant protein in transplastomic tobacco plants was estimated by ELISA analysis using a specific antibody. The protein was purified from total soluble protein, insoluble protein aggregates and the protein was extracted from the isolated chloroplast using nickel resin and a chromatography column. After digestion of the purified protein with factor Xa, the presence of the purified tPA protein was confirmed by western blot analysis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    The friendly bacteria within us Commensal bacteria of the intestine: Roles in health and disease B.S. Ramakrishna Professor & Head Gastroenterology & Hepatology Christian Medical College Vellore · Slide 2 · Intestinal bacteria: the hidden organ · Slide 4 · Slide 5 · The normal bacterial flora prevents GI disease · Slide 7.

  11. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    Short chain fatty acids (SCFA) are main source of energy for colonic epithelial cells · SCFA – role in colonic disease · SCFA prevent mucosal inflammation · Immunoregulation by gut bacteria · Balance of bacterial species in the gut · Immunosensory detection of intestinal bacteria · Pathogenic bacteria release interleukin-8 ...

  12. [Purification and production of the extracellular 5-aminolevulinate from recombiniant Escherichia coli expressing yeast ALAS].

    Science.gov (United States)

    He, Xiao-Mei; Zhou, Jing; Cheng, Ying; Fan, Jun

    2007-05-01

    Aminolevulinic acid (ALA) is biosynthesized by the enzyme ALA synthase (ALAS). The ALA production has been studied using the overproducing ALAS from several bacteria in Escherchia coil, respectively. However, ALAS from eucaryote expressed in E. coli for producing ALA in the culture is not known. The extracellular ALA production and cell growth were investageted respectively using the recombinant E. coli overproducing Saccharomyces cerevisiae ALAS in shake-flask fermentations. The ALAS activity from the cell extract was assayed. The extracellular ALA was purified by the national-made large-dimension resins and confirmed by the capillary electrophoresis measurements. At 12h after induction at 37 degrees C, the extracellular ALA production was up to 162mg per liter LB culture at initial pH 6.5 with exogenous levulinate, succinate and and glycine at the concentration of 20 mmol/L respectively. The purity of ALA after purification is up to 90%.

  13. Simultaneous separation and purification of flavonoids and oleuropein from Olea europaea L. (olive) leaves using macroporous resin.

    Science.gov (United States)

    Li, Chen; Zheng, Yuanyuan; Wang, Xiaofei; Feng, Shilan; Di, Duolong

    2011-12-01

    This study developed a feasible process to simultaneously separate and purify polyphenols, including flavonoids and oleuropein, from the leaves of Olea europaea L. Macroporous resins were used as the separation and purification materials. The performance and separation capabilities of eight resins (D101, DM130, HPD450, LSA-21, LSA-40, 07C, LSD001 and HPD600) were systematically evaluated. The contents of target polyphenols in different extracts were determined using ultraviolet (for flavonoids) and high-performance liquid chromatographic (for oleuropein) methods. The static adsorption and desorption results showed that resin LSA-21 had better adsorption properties among the eight resins. Influential factors such as extraction method, pH value of feeding solution, desorption solution, adsorption kinetics and adsorption isotherm, etc. to the extraction and purification of these polyphenols were successively investigated on resin LSA-21. The target flavonoids and oleuropein were selectively purified using resin LSA-21. Compared with the contents in raw leaves, the contents of total flavonoids and oleuropein in the final purified products were increased 13.2-fold (from 16 to 211 g kg(-1) ) and 7.5-fold (from 120 to 902 g kg(-1) ) with recovery yields of 87.9% and 85.6%, respectively. This extraction and purification method could be used in the large-scale enrichment or purification of flavonoids, oleuropein and other polyphenols from O. europaea L. leaves or other herbal materials in industrial, food processing and medical manufacture. Copyright © 2011 Society of Chemical Industry.

  14. Non-chromatographic purification of recombinant elastin-like polypeptides and their fusions with peptides and proteins from Escherichia coli.

    Science.gov (United States)

    MacEwan, Sarah R; Hassouneh, Wafa; Chilkoti, Ashutosh

    2014-06-09

    Elastin-like polypeptides are repetitive biopolymers that exhibit a lower critical solution temperature phase transition behavior, existing as soluble unimers below a characteristic transition temperature and aggregating into micron-scale coacervates above their transition temperature. The design of elastin-like polypeptides at the genetic level permits precise control of their sequence and length, which dictates their thermal properties. Elastin-like polypeptides are used in a variety of applications including biosensing, tissue engineering, and drug delivery, where the transition temperature and biopolymer architecture of the ELP can be tuned for the specific application of interest. Furthermore, the lower critical solution temperature phase transition behavior of elastin-like polypeptides allows their purification by their thermal response, such that their selective coacervation and resolubilization allows the removal of both soluble and insoluble contaminants following expression in Escherichia coli. This approach can be used for the purification of elastin-like polypeptides alone or as a purification tool for peptide or protein fusions where recombinant peptides or proteins genetically appended to elastin-like polypeptide tags can be purified without chromatography. This protocol describes the purification of elastin-like polypeptides and their peptide or protein fusions and discusses basic characterization techniques to assess the thermal behavior of pure elastin-like polypeptide products.

  15. Manufacture of Probiotic Bacteria

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  16. Bacteria in ulcera crurum.

    Science.gov (United States)

    Kontiainen, S; Rinne, E

    1988-01-01

    Bacterial cultures derived from 432 chronic leg ulcers were analysed retrospectively to determine which bacteria are most commonly found in these ulcers. The study covered a 2-year period. Two-thirds of the patients were over 70 years of age. Staphylococcus aureus was found in nearly half of the ulcers studied, Pseudomonas sp. in one-third, pyogenic streptococci and enterococci in every fifth and Proteus sp. in every tenth. The frequency by which pyogenic streptococci were isolated was about 10 to 20 times as high as previously reported. Obligate anaerobic bacteria were also frequently isolated. The sensitivity of the isolates from the second year to antimicrobial agents likely to be chosen if systemic therapy were required is also reported. The results are discussed in relation to previous findings.

  17. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA) biosynthesis

    OpenAIRE

    Chen, Guo-Qiang; Jiang, Xiao-Ran

    2017-01-01

    Polyhydroxyalkanoates (PHA) have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw) and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth...

  18. Chemotactic waves of bacteria at the mesoscale

    OpenAIRE

    Calvez, Vincent

    2016-01-01

    The existence of travelling waves for a model of concentration waves of bacteria is investigated. The model consists in a kinetic equation for the biased motion of cells following a run-and-tumble process, coupled with two reaction-diffusion equations for the chemical signals. Strong mathematical difficulties arise in comparison with the diffusive regime which was studied in a previous work. The cornerstone of the proof consists in establishing monotonicity properties of the spatial density o...

  19. Bacteria in ancient sediments

    International Nuclear Information System (INIS)

    Izzo, G.

    1986-01-01

    In order to ascertain the role of biological activity in ancient sediments, two microbiological studies were carried out. The first was on pleistocenic clay sediments on land, the second on deep oceanic sediments. In the present paper by direct counting the samples is demonstrated the presence of bacteria in a range of 10 5 to 10 7 . Further studies must be carried out to ascertain the activities by in situ incubation methods

  20. Bacteria colonizing paper machines

    OpenAIRE

    Ekman, Jaakko

    2011-01-01

    Bacteria growing in paper machines can cause several problems. Biofilms detaching from paper machine surfaces may lead to holes and spots in the end product or even break the paper web leading to expensive delays in production. Heat stable endospores will remain viable through the drying section of paper machine, increasing the microbial contamination of paper and board. Of the bacterial species regularly found in the end products, Bacillus cereus is the only one classified as a pathogen. Cer...