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Sample records for bacteria purification properties

  1. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    Directory of Open Access Journals (Sweden)

    José Luis Parada

    2007-05-01

    Full Text Available Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS, useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therapeutic antibiotics. In this context, bacteriocins are indicated to prevent the growth of undesirable bacteria in a food-grade and more natural way, which is convenient for health and accepted by the community. According to their properties, structure, molecular weight (MW, and antimicrobial spectrum, bacteriocins are classified in three different groups: lantibiotics and non-lantibiotics of low MW, and those of higher MW. Several strategies for isolation and purification of bacteriocins from complex cultivation broths to final products were described. Biotechnological procedures including salting-out, solvent extraction, ultrafiltration, adsorption-desortion, ion-exchange, and size exclusion chromatography are among the most usual methods. Peptide structure-function studies of bacteriocins and bacterial genetic advances will help to understand the molecular basis of their specificity and mode of action. Nisin is a good example of commercial success, and a good perspective is open to continue the study and development of new bacteriocins and their biotechnological applications. These substances in appropriate concentrations may be used in veterinary medicine and as animal growth promoter instead usual antibiotics, as well as an additional hurdle factor for increasing the shelf life of minimal processed foods.

  2. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    OpenAIRE

    Parada,José Luis; Caron,Carolina Ricoy; Medeiros,Adriane Bianchi P.; Soccol,Carlos Ricardo

    2007-01-01

    Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS), useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therap...

  3. Purification of bacteriocins produced by lactic acid bacteria.

    Science.gov (United States)

    Saavedra, Lucila; Castellano, Patricia; Sesma, Fernando

    2004-01-01

    Bacteriocins are antibacterial substances of a proteinaceous nature that are produced by different bacterial species. Lactic acid bacteria (LAB) produce biologically active peptides or protein complexes that display a bactericidal mode of action almost exclusively toward Gram-positive bacteria and particularly toward closely related species. Generally they are active against food spoilage and foodborne pathogenic microorganisms including Bacillus cereus, Clostridium perfringens, Staphylococcus aureus, and Listeria monocytogenes. There is an increased tendency to use natural occurring metabolites to prevent the growth of undesirable flora in foodstuffs. These metabolites could replace the use of chemical additives such as sorbic acid, sulfur dioxide, nitrite, nitrate, and others. For instance, bacteriocins produced by LAB may be promising for use as bio-preservaties. Bacteriocins of lactic acid bacteria are typically cationic, hydrophobic peptides and differ widely in many characteristics including molecular weight, presence of particular groups of amino acids, pI, net positive charge, and post-translational modifications of certain amino acids. This heterogeneity within the LAB bacteriocins may explain the different procedures for isolation and purification developed so far. The methods most frequently used for isolation, concentration, and purification involve salt precipitation of bacteriocins from culture supernatants, followed by various combinations of gel filtration, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). In this chapter, a protocol is described that combines several methods used in our laboratory for the purification of two cationic bacteriocins, Lactocin 705AL and Enterocin CRL10, produced by Lactobacillus casei CRL705 and Enterococcus mundtii CRL10, respectively.

  4. 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...

  5. 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.

  6. [Study on influence between activated carbon property and immobilized biological activated carbon purification effect].

    Science.gov (United States)

    Wang, Guang-zhi; Li, Wei-guang; He, Wen-jie; Han, Hong-da; Ding, Chi; Ma, Xiao-na; Qu, Yan-ming

    2006-10-01

    By means of immobilizing five kinds of activated carbon, we studied the influence between the chief activated carbon property items and immobilized bioactivated carbon (IBAC) purification effect with the correlation analysis. The result shows that the activated carbon property items which the correlation coefficient is up 0.7 include molasses, abrasion number, hardness, tannin, uniform coefficient, mean particle diameter and effective particle diameter; the activated carbon property items which the correlation coefficient is up 0.5 include pH, iodine, butane and tetrachloride. In succession, the partial correlation analysis shows that activated carbon property items mostly influencing on IBAC purification effect include molasses, hardness, abrasion number, uniform coefficient, mean particle diameter and effective particle diameter. The causation of these property items bringing influence on IBAC purification is that the activated carbon holes distribution (representative activated carbon property item is molasses) provides inhabitable location and adjust food for the dominance bacteria; the mechanical resist-crash property of activated carbon (representative activated carbon property items: abrasion number and hardness) have influence on the stability of biofilm; and the particle diameter size and distribution of activated carbon (representative activated carbon property items: uniform coefficient, mean particle diameter and effective particle diameter) can directly affect the force of water in IBAC filter bed, which brings influence on the dominance bacteria immobilizing on activated carbon.

  7. 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.

  8. 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.

  9. Antioxidant Properties of Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2017-05-01

    Full Text Available 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.

  10. Bacteriocins from lactic acid bacteria: production, purification, and food applications.

    Science.gov (United States)

    De Vuyst, Luc; Leroy, Frédéric

    2007-01-01

    In fermented foods, lactic acid bacteria (LAB) display numerous antimicrobial activities. This is mainly due to the production of organic acids, but also of other compounds, such as bacteriocins and antifungal peptides. Several bacteriocins with industrial potential have been purified and characterized. The kinetics of bacteriocin production by LAB in relation to process factors have been studied in detail through mathematical modeling and positive predictive microbiology. Application of bacteriocin-producing starter cultures in sourdough (to increase competitiveness), in fermented sausage (anti-listerial effect), and in cheese (anti-listerial and anti-clostridial effects), have been studied during in vitro laboratory fermentations as well as on pilot-scale level. The highly promising results of these studies underline the important role that functional, bacteriocinogenic LAB strains may play in the food industry as starter cultures, co-cultures, or bioprotective cultures, to improve food quality and safety. In addition, antimicrobial production by probiotic LAB might play a role during in vivo interactions occurring in the human gastrointestinal tract, hence contributing to gut health.

  11. 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

  12. 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.

  13. 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) ...

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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...... of categories can be understood as practices of purification. However, a purely technical grip on water is never possible. Unruly elements, like weather, contamination, urban dwellers, and competing interests, interfere and make processes of intervention unstable. Water is never completely cleaned, and, equally...

  20. Purification and characterization of two bacteriocins produced by lactic acid bacteria isolated from Mongolian airag.

    Science.gov (United States)

    Batdorj, B; Dalgalarrondo, M; Choiset, Y; Pedroche, J; Métro, F; Prévost, H; Chobert, J-M; Haertlé, T

    2006-10-01

    The aim of this study was to isolate and identify bacteriocin-producing lactic acid bacteria (LAB) issued from Mongolian airag (traditional fermented mare's milk), and to purify and characterize bacteriocins produced by these LAB. Identification of the bacteria (Enterococcus durans) was carried out on the basis of its morphological, biochemical characteristics and carbohydrate fermentation profile and by API50CH kit and 16S rDNA analyses. The pH-neutral cell-free supernatant of this bacterium inhibited the growth of several Lactobacillus spp. and food-borne pathogens including Escherichia coli, Staphylococcus aureus and Listeria innocua. The antimicrobial agent (enterocin A5-11) was heat stable and was not sensitive to acid and alkaline conditions (pH 2-10), but was sensitive to several proteolytic enzymes. Its inhibitory activity was completely eliminated after treatment with proteinase K and alpha-chymotrypsin. The activity was however not completely inactivated by other proteases including trypsin and pepsin. Three-step purification procedure with high recovery yields was developed to separate two bacteriocins. The applied procedure allowed the recovery of 16% and 64% of enterocins A5-11A and A5-11B, respectively, present in the culture supernatant with purity higher than 99%. SDS-PAGE analyses revealed that enterocin A5-11 has a molecular mass of 5000 Da and mass spectrometry analyses demonstrates molecular masses of 5206 and 5218 Da for fractions A and B, respectively. Amino acid analyses of both enterocins indicated significant quantitative difference in their contents in threonine, alanine, isoleucine and leucine. Their N-termini were blocked hampering straightforward Edman degradation. Bacteriocins A5-11A and B from Ent. durans belong to the class II of bacteriocins. Judging from molecular masses, amino acid composition and spectrum of activities, bacteriocins A5-11A and B from Ent. durans show high degree of similarity with enterocins L50A and L50B

  1. Lactic Acid Bacteria Exopolysaccharides in Foods and Beverages: Isolation, Properties, Characterization, and Health Benefits.

    Science.gov (United States)

    Lynch, Kieran M; Zannini, Emanuele; Coffey, Aidan; Arendt, Elke K

    2018-03-25

    Exopolysaccharides produced by lactic acid bacteria are a diverse group of polysaccharides produced by many species. They vary widely in their molecular, compositional, and structural characteristics, including mechanisms of synthesis. The physiochemical properties of these polymers mean that they can be exploited for the sensorial and textural enhancement of a variety of food and beverage products. Traditionally, lactic acid bacteria exopolysaccharides have an important role in fermented dairy products and more recently are being applied for the improvement of bakery products. The health benefits that are continually being associated with these polysaccharides enable the development of dual function, added-value, and clean-label products. To fully exploit and understand the functionality of these exopolysaccharides, their isolation, purification, and thorough characterization are of great importance. This review considers each of the above factors and presents the current knowledge on the importance of lactic acid bacteria exopolysaccharides in the food and beverage industry.

  2. [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

  3. Purification of water polluted with oil and sulfurous closed-ring and aromatic compounds contained in oil and oil products using bacteria relating to thiosphaera

    International Nuclear Information System (INIS)

    Kurashov, V.M.; Sakhno, T.V.; Gavrilov, V.S.; Zijatdinov, R.N.

    2005-01-01

    The intensity of natural purification (self-purification) of reservoirs polluted with oil and oil products is determined by microorganisms. Hydrocarbon-oxidizing microorganisms are constant natural constituent of biocenose in reservoirs. However, as a result of outflows, the oil and oil products concentration exceeds maximum values allowing normal vital functions of microorganisms resulting in breaking micro-biocenose suppression of vital functions of bacteria. In this regard, elective anaerobic microorganisms of Thiosphaera are worthy of notice. We found out that bacteria belonging to Thiosphaera pantotropha decomposed oil at high oil concentrations in water (at oil concentration like 1 liter of oil in 1 liter of water). And this is when aerobic microorganisms lose their vital functions at maximum concentration of 20 g of oil in 1 liter of water. To intensify the process of oil decomposition we emulsified oil with aqueous solutions of salts. Thiosphaera pantotropha are found out to decompose oil in a wide range of ratio between oil and aqueous solutions of salts: from 1:10 to 10:1. The water solutions salinity made from 20 g/l to 80 g/l. It must be noticed that, since the Thiosphaera pantotropha are elective anaerobes and decompose oil both in presence and in absence of oxygen, it is not necessary anymore to conduct the process under strictly anaerobic conditions and to supply additional oxygen. This makes it possible to simplify the process of biodegradation of oil and to make this process practically more feasible and economically more profitable being compared to the processes based on the use of other species of bacteria. We found out that Thiosphaera decompose sulfurous closed-ring and aromatic compounds in oil which are chemically and thermally stable and can be hardly decomposed, and possess extremely poisonous properties, as well. The use of microorganisms of Thiosphaera pantotropha allows to purify waters polluted with oil and oil products both during

  4. Partial Purification Characterization and Application of Bacteriocin from Bacteria Isolated Parkia biglobosa Seeds

    OpenAIRE

    Olorunjuwon, O. Bello; Olubukola, O. Babalola; Mobolaji, Adegboye; Muibat, O. Fashola; Temitope, K. Bello

    2018-01-01

    Bacteriocins are proteinaceous toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strains. Fermented Parkia biglobosa seeds (African locust bean) were screened for bacteriocin-producing lactic acid bacteria (LAB) with the characterization of putative bacteriocins. Bacteriocin-producing lactic acid bacteria (LAB) were identified by 16s rDNA sequencing. Molecular sizes of the bacteriocins were determined using the tricine-sodium dodecyl sulphate-polyacryla...

  5. 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

  6. Energy efficiency method of purification of water and air from bacteria

    International Nuclear Information System (INIS)

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

    2005-01-01

    Full text: Creation of harmless and cheap water disinfection methods is one of important tasks today. Besides most of building ventilation systems and air conditioners using in many countries have inside some capacity of water as the component allowing to cooling air. There is a chance that if anthrax or legionella or several other dangerous bacteria will be entered in this water then such conditioners will become the source of infection, and it can lead to catastrophic consequences. To prevent this possibility we offer to set in each source of drinking water or air conditioner (especially those in public places) mini-size cheap energy-effective device developed using our new technology. This me of water disinfection is based on using of electrochemical processes treatment by electrostatic field. Experimental results from tests conducted in Uzbekistan, the United States, Russia, etc. concerning the destruction of vegetative forms of bacteria follow: Energy consumption of the unit with a production capacity of 5 cubic meters of water per hour did not exceed 50 watts. This is significantly less than conventional methods. The destruction time for bacteria did not exceed 60 minutes at a bacterial concentration 1000 CFU/L. Spores are more resistant to destruction than vegetative cells (orders of magnitude more difficult). Preliminary test results for destroying the spore form of bacteria follow: Bacteria destruction time was 2 hours at an initial concentration of 1000 CFU/L. Energy consumption of the unit with a production capacity of 5 cubic meters of water per hour did not exceed 50 watts The purpose of this work is further elaboration of this technology, and its accommodation to conditions of different countries. Test models will be made and tested in laboratories of interested countries. Research would be conducted with acceptable bacteria and analog spores. As the result, new cheap and energy-effective devices for disinfection of drinking water and defense of

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

    NARCIS (Netherlands)

    Janssen, A.J.H.; Lens, P.N.L.; Stams, A.J.M.; Plugge, C.M.; Sorokin, D.Y.; Muyzer, G.; Dijkman, H.; Zessen, van E.; Luimes, F.J.T.; Buisman, C.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

  8. Partial Purification, Characterization and Application of Bacteriocin from Bacteria Isolated Parkia biglobosa Seeds

    Directory of Open Access Journals (Sweden)

    Olorunjuwon O. Bello

    2018-05-01

    Full Text Available Bacteriocins are proteinaceous toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strains. Fermented Parkia biglobosa seeds (African locust bean were screened for bacteriocin-producing lactic acid bacteria (LAB with the characterization of putative bacteriocins. Bacteriocin-producing lactic acid bacteria (LAB were identified by 16s rDNA sequencing. Molecular sizes of the bacteriocins were determined using the tricine-sodium dodecyl sulphate-polyacrylamide gel electrophoresis (tricine-SDS–PAGE and effects of enzymes, pH, detergents and temperature on bacteriocin activity investigated, using standard procedures. Bacteriocins production and activities were measured by spectrophotometric analysis. Statistical analysis was carried out using student t-test and Analyses of Variance. Bacteriocigenic LAB isolated were Lactobacillus plantarum Z1116, Enterococcus faecium AU02 and Leuconostoc lactis PKT0003. They inhibited the growth of both Gram-positive and Gram-negative bacteria. The sizes of bacteriocins Z1116, AU02 and PKT0003 were 3.2 kDa, 10 kDa and 10 kDa, respectively. The synergistic effects of characterized bacteriocins and rifampicin tested on organisms showed significant differences (P < 0.05, as compared with the effects of only one of the two. The antimicrobial activity of the three bacteriocins was deactivated after treatment of the cell-free supernatants with proteinase K, papain, pepsin and trypsin. Parkia biglobosa seeds are, therefore, rich in LAB bacteriocins which could be explored. The biosynthetic mechanisms of LAB bacteriocins could be employed in food safety and security, preservation, peptide design, infection control and pharmacotherapy. This should help in the control of undesirable bacteria and in designing more potent and selective antimicrobial peptides.

  9. Purification and some kinetic properties of catalase from parsley (Petroselinum hortense Hoffm., Apiaceae) leaves.

    Science.gov (United States)

    Oztürk, Lokman; Bülbül, Metin; Elmastas, Mahfuz; Ciftçi, Mehmet

    2007-01-01

    In this study, catalase (CAT: EC 1.11.1.6) was purified from parsley (Petroselinum hortense) leaves; analysis of the kinetic behavior and some properties of the enzyme were investigated. The purification consisted of three steps, including preparation of homogenate, ammonium sulfate fractionation, and fractionation by DEAE-Sephadex A50 ion exchange chromatography. The enzyme was obtained with a yield of 9.5% and had a specific activity of 1126 U (mg proteins)(-1). The overall purification was about 5.83-fold. A temperature of 4 degrees C was maintained during the purification process. Enzyme activity was spectrophotometrically measured at 240 nm. In order to control the purification of the enzyme, SDS-polyacrylamide gel electrophoresis was carried out in 4% and 10% acryl amide for stacking and running gel, respectively. SDS-polyacrylamide gel electrophoresis showed a single band for the enzyme. The molecular weight was found to be 183.29 kDa by Sephadex G-200 gel filtration chromatography. The stable pH, optimum pH, and ionic strength were determined for phosphate and Tris-HCl buffer systems. In addition, K(M) and V(max) values for H(2)O(2), at optimum pH and 25 degrees C, were determined by means of Lineweaver-Burk plots.

  10. Anaerobic Ammonium-Oxidizing Bacteria: Unique Microorganisms with Exceptional Properties

    Science.gov (United States)

    Jetten, Mike S. M.

    2012-01-01

    Summary: Anaerobic ammonium-oxidizing (anammox) bacteria defy many microbiological concepts and share numerous properties with both eukaryotes and archaea. Among their most intriguing characteristics are their compartmentalized cell plan and archaeon-like cell wall. Here we review our current knowledge about anammox cell biology. The anammox cell is divided into three separate compartments by bilayer membranes. The anammox cell consists of (from outside to inside) the cell wall, paryphoplasm, riboplasm, and anammoxosome. Not much is known about the composition or function of both the anammox cell wall and the paryphoplasm compartment. The cell wall is proposed to be proteinaceous and to lack both peptidoglycan and an outer membrane typical of Gram-negative bacteria. The function of the paryphoplasm is unknown, but it contains the cell division ring. The riboplasm resembles the standard cytoplasmic compartment of other bacteria; it contains ribosomes and the nucleoid. The anammoxosome occupies most of the cell volume and is a so-called “prokaryotic organelle” analogous to the eukaryotic mitochondrion. This is the site where the anammox reaction takes place, coupled over the curved anammoxosome membrane, possibly giving rise to a proton motive force and subsequent ATP synthesis. With these unique properties, anammox bacteria are food for thought concerning the early evolution of the domains Bacteria, Archaea, and Eukarya. PMID:22933561

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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)

  17. 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 ...

  18. Purification of 6-phosphogluconate dehydrogenase from parsley (Petroselinum hortense) leaves and investigation of some kinetic properties.

    Science.gov (United States)

    Demir, Hülya; Ciftçi, Mehmet; Küfrevioğlu, O Irfan

    2003-02-01

    In this study, 6-phosphogluconate dehydrogenase (E.C.1.1.44; 6PGD) was purified from parsley (Petroselinum hortense) leaves, and analysis of the kinetic behavior and some properties of the enzyme were investigated. The purification consisted of three steps that are preparation of homogenate ammonium sulfate fractionation and on DEAE-Sephadex A50 ion exchange. The enzyme was obtained with a yield of 49% and had a specific activity of 18.3 U (mg proteins)(-1) (Lehninger, A.L.; Nelson, D.L.; Cox, M.M. Principles of Biochemistry, 2nd Ed.; Worth Publishers Inc.: N.Y., 2000, 558-560). The overall purification was about 339-fold. A temperature of +4 degrees C was maintained during the purification process. Enzyme activity was spectrophotometrically measured according to the Beutler method at 340 mn. In order to control the purification of the enzyme, SDS-polyacrylamide gel electrophoresis was carried out in 4% and 10% acrylamide for stacking and running gel, respectively. SDS-polyacrylamide gel electrophoresis showed a single band for enzyme. The molecular weight was found to be 97.5 kDa by Sephadex G-150 gel filtration chromatography. A protein band corresponding to a subunit molecular weight of 24.1 kDa was obtained on SDS-polyacrylamide gel electrophoresis. For the enzymes, the stable pH, optimum pH, and optimum temperature were found as 8.0, 8.0, and 50 degrees C, respectively. In addition, KM and Vmax values for NADP+ and G6-P at optimum pH and 25 degrees C were determined by means of Lineweaver-Burk plots.

  19. Enhancement of properties of recycled coarse aggregate concrete using bacteria

    Science.gov (United States)

    Sahoo; Arakha; Sarkar; P; Jha

    2016-01-01

    Due to rapid construction, necessity for raw materials of concrete, especially coarse aggregate, tends to increase the danger of early exhaustion of the natural resources. An alternative source of raw materials would perhaps delay the advent of this early exhaustion. Recycled coarse aggregate (RCA) plays a great role as an alternative raw material that can replace the natural coarse aggregate (NCA) for concrete. Previous studies show that the properties of RCA concrete are inferior in quality compared to NCA concrete. This article attempts to study the improvement of properties of RCA concrete with the addition of bacteria named as Bacillus subtilis. The experimental investigation was carried out to evaluate the improvement of the compressive strength, capillary water absorption, and drying shrinkage of RCA concrete incorporating bacteria. The compressive strength of RCA concrete is found to be increased by about 20% when the cell concentration of B. subtilis is 106 cells/ml. The capillary water absorption as well as drying shrinkage of RCA are reduced when bacteria is incorporated. The improvement of RCA concrete is confirmed to be due to the calcium carbonate precipitation as observed from the microstructure studies carried out on it such as EDX, SEM, and XRD.

  20. 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.

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Taira, H; Ejiri, S I; Shimura, K [Tohoku Univ., Sendai (Japan). Faculty of Agriculture

    1972-12-01

    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-..gamma..-/sup 32/P was prepared from GDP and /sup 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.

  3. PURIFICATION AND SOME PROPERTIES OF CELLULASE FROM ODONTOTERMES FORMOSANUS (ISOPTERA: TERMITIDAE)

    Institute of Scientific and Technical Information of China (English)

    Tian-ciYang; Jian-chuMo; Jia-anCheng

    2004-01-01

    The purification of the cellulase from Odontotermes forrnosanus workers was achieved by using anion-exchange column of UNOsphere Q, BioLogic DuoFlow chromatography system. The purified cellulase was identified as an endoglucanase and some of its properties were investigated. The EGase activity was 807.5-fold as high as the initial enzyme activity using CMC as substrate and 14.4-fold using salicin as substrate. The enzyme preparations were homogeneous as judged by SDS-PAGE electrophoresis, molecular weight of which was 80 kDa and confirmed by 2-DE zymogram analysis. The enzyme was isoelectric at pH 6.4, which was active on CMC substrate.

  4. 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.)

  5. 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.

  6. 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)

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

    Science.gov (United States)

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

    2014-07-01

    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.

  8. Extraction, purification, kinetic and thermodynamic properties of urease from germinating Pisum Sativum L. seeds

    Science.gov (United States)

    2014-01-01

    Background Urease, one of the highly efficient known enzymes, catalyzes the hydrolysis of urea into ammonia and carbon dioxide. The present study aimed to extract urease from pea seeds (Pisum Sativum L). The enzyme was then purified in three consequence steps: acetone precipitation, DEAE-cellulose ion-exchange chromatography, and gel filtration chromatography (Sephacryl S-200 column). Results The purification fold was 12.85 with a yield of 40%. The molecular weight of the isolated urease was estimated by chromatography to be 269,000 Daltons. Maximum urease activity (190 U/g) was achieved at the optimum conditions of 40°C and pH of 7.5 after 5 min of incubation. The kinetic parameters, K m and V max , were estimated by Lineweaver-Burk fits and found to be 500 mM and 333.3 U/g, respectively. The thermodynamic constants of activation, ΔH, E a , and ΔS, were determined using Arrhenius plot and found to be 21.20 kJ/mol, 23.7 kJ/mol, and 1.18 kJ/mol/K, respectively. Conclusions Urease was purified from germinating Pisum Sativum L. seeds. The purification fold, yield, and molecular weight were determined. The effects of pH, concentration of enzyme, temperature, concentration of substrate, and storage period on urease activity were examined. This may provide an insight on the various aspects of the property of the enzyme. The significance of extracting urease from different sources could play a good role in understanding the metabolism of urea in plants. PMID:25065975

  9. Antimicrobial properties of probiotic bacteria from various sources

    African Journals Online (AJOL)

    OKEREKE HOPE C

    2012-05-15

    May 15, 2012 ... The lactic acid bacteria (LAB), a component of several fermented foods including ... lactic acid bacteria grown in MRS broth for 20 to 24 h using centrifugation .... vacuum packed chill-stored meat has potential application for ...

  10. Field Emission Property of Double-walled Carbon Nanotubes Related to Purification and Transmittance

    International Nuclear Information System (INIS)

    Ahn, KiTae; Jang, HyunChul; Hong, Wanshick; Park, Kyoungwan; Sok, Junghyun; Lyu, SeungChul; Lee, Hansung; Lee, Naesung; Han, Moonsup; Park, Yunsun

    2011-01-01

    Double-walled carbon nanotubes (DWCNTs) with high purity were produced by the catalytic decomposition of tetrahydrofuran (THF) using a Fe-Mo/MgO catalyst at 800°C. The as-synthesized DWCNTs typically have catalytic impurities and amorphous carbon, which were removed by a two-step purification process consisting of acid treatment and oxidation. In the acid treatment, metallic catalysts were removed in HCl at room temperature for 5 hr with magnetic stirring. Subsequently, the oxidation, using air at 380°C for 5 hr in the a vertical-type furnace, was used to remove the amorphous carbon particles. The DWCNT suspension was prepared by dispersing the purified DWCNTs in the aqueous sodium dodecyl sulfate solution with horn-type sonication. This was then air-sprayed on ITO glass to fabricate DWCNT field emitters. The field emission properties of DWCNT films related to transmittance were studied. This study provides the possibility of the application of large-area transparent CNT field emission cathodes.

  11. 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.

  12. A study of magnetic properties of magnetotatic bacteria

    International Nuclear Information System (INIS)

    Wajnberg, E.; Souza, L.H. de; Barros, H.G. de P.L. de; Esquivel, D.M.S.

    1985-01-01

    The average magnetic moment and its anisotropy are determined in natural samples of magnetotactic bacteria at 4.2 K using a SQUID magnetometer. The results are in good agreement with estimates made from electron micrographs. (Author) [pt

  13. 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.

  14. Biophysical properties of membrane lipids of anammox bacteria : I. Ladderane phospholipids form highly organized fluid membranes

    NARCIS (Netherlands)

    Boumann, Henry A.; Longo, Marjorie L.; Stroeve, Pieter; Poolman, Bert; Hopmans, Ellen C.; Stuart, Marc C. A.; Damste, Jaap S. Sinninghe; Schouten, Stefan

    Anammox bacteria that are capable of anaerobically oxidizing ammonium (anammox) with nitrite to nitrogen gas produce unique membrane phospholipids that comprise hydrocarbon chains with three or five linearly condensed cyclobutane rings. To gain insight into the biophysical properties of these

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

    African Journals Online (AJOL)

    SARAH

    2014-03-31

    Mar 31, 2014 ... Acetic acid bacteria in Côte d'Ivoire cocoa fermentation ... Six day heap fermentation on banana leaves was conducted at farm level ... reactions responsible for the final quality of the ... harvested from Agboville (geographic coordinates 5°59' .... Figure 1: Evolution of temperature (A) and pH (B) during cocoa ...

  17. Purification and investigation of some kinetic properties of glucose-6-phosphate dehydrogenase from parsley (Petroselinum hortense) leaves.

    Science.gov (United States)

    Coban, T Abdül Kadir; Ciftçi, Mehmet; Küfrevioğlu, O Irfan

    2002-05-01

    In this study, glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP+ oxidoreductase, EC 1.1.1.49; G6PD) was purified from parsley (Petroselinum hortense) leaves, and analysis of the kinetic behavior and some properties of the enzyme were investigated. The purification consisted of three steps: preparation of homogenate, ammonium sulfate fractionation, and DEAE-Sephadex A50 ion exchange chromatography. The enzyme was obtained with a yield of 8.79% and had a specific activity of 2.146 U (mg protein)(-1). The overall purification was about 58-fold. Temperature of +4 degrees C was maintained during the purification process. Enzyme activity was spectrophotometrically measured according to the Beutler method, at 340 nm. In order to control the purification of enzyme, SDS-polyacrylamide gel electrophoresis was carried out in 4% and 10% acrylamide for stacking and running gel, respectively. SDS-polyacrylamide gel electrophoresis showed a single band for enzyme. The molecular weight was found to be 77.6 kDa by Sephadex G-150 gel filtration chromatography. A protein band corresponding to a molecular weight of 79.3 kDa was obtained on SDS-polyacrylamide gel electrophoresis. For the enzymes, the stable pH, optimum pH, and optimum temperature were found to be 6.0, 8.0, and 60 degrees C, respectively. Moreover, KM and Vmax values for NADP+ and G6-P at optimum pH and 25 degrees C were determined by means of Lineweaver-Burk graphs. Additionally, effects of streptomycin sulfate and tetracycline antibiotics were investigated for the enzyme activity of glucose-6-phosphate dehydrogenase in vitro.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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

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

    Science.gov (United States)

    2012-01-01

    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 alternative to the

  4. 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.

  5. 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)

  6. Purification and synergistic antibacterial activity of arginine derived cyclic dipeptides, from Achromobacter sp. associated with a rhabditid entomopathogenic nematode against major clinically relevant biofilm forming wound bacteria

    Directory of Open Access Journals (Sweden)

    NISHANTH KUMAR S

    2015-08-01

    Full Text Available Skin and chronic wound infections caused by various pathogenic bacteria are an increasing and urgent health problem worldwide. In the present study ethyl acetate cell-free culture filtrate of an Achromobacter sp. associated with a Rhabditis entomopathogenic nematode (EPN, displayed promising antibacterial property and was further purified by silica gel column chromatography to get three different cyclic dipeptides (CDPs. Based on the spectral data and Marfey’s analyses, the CDPs were identified as cyclo(D-Leu-D-Arg (1, cyclo(L-Trp-L-Arg (2, and cyclo(D-Trp-D-Arg (3, respectively. Three CDPs were active against all the ten wound associated bacteria tested. The significant antibacterial activity was recorded by CDP 3, and highest activity of 0.5 µg/ml was recorded against Staphylococcus aureus and Pseudomonas aeruginosa. The synergistic antibacterial activities of CDPs and ampicillin were assessed using the checkerboard microdilution method. The results of the current study recorded that the combined effects of CDPs and ampicillin principally recorded synergistic activity. Interestingly, the combination of CDPs and ampicillin also recorded enhanced inhibited biofilm formation by bacteria. Moreover, CDPs significantly stimulate the production of the anti-inflammatory cytokines IL-10 and IL-4 by human peripheral blood mononuclear cells but are without significant effect on the production of TNF-α, a pro-inflammatory cytokines. The three CDPs have been examined for their activities against intracellular S. aureus in murine macrophages (J774 using 24 h exposure to 1X and 2X MIC concentrations. Significance decrease in intracellular S. aureus burden was recorded by CDPs. CDPs also recorded no cytotoxicity towards FS normal fibroblast, VERO and L231 normal lung epithelial cell lines. Antimicrobial activity of the arginine containing CDPs against the wound associated bacteria is reported here for the first. Moreover, this is also the report on the

  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. 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...

  9. 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...... 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...

  10. Purification and properties of extracellular polysaccharide (EPS) antigens produced by different mould species.

    Science.gov (United States)

    Notermans, S; Wieten, G; Engel, H W; Rombouts, F M; Hoogerhout, P; van Boom, J H

    1987-02-01

    Extracellular polysaccharide (EPS) antigens produced by different mould species were purified and partially characterized. Purification included (NH4)2SO4 treatment, Sepharose CL-4B column chromatography and Con A-sepharose chromatography. The EPS of Penicillium digitatum, Mucor racemosus and Cladosporium cladosporioides showed high antigenic capacities. Immunologically the EPS were partially genus-specific, but cross-reactivity was observed. The EPS antigens produced by species of Penicillium, Aspergillus repens and Geotrichum candidum lost their immunological activity upon heating (100 degrees C) at pH 1.8, while the EPS antigen of M. racemosus, Rhizopus oligosporus and C. cladosporioides were stable under the same conditions. The dominant monosaccharides present in the EPS antigen were mannose, galactose and glucose. The EPS obtained from cultures of M. racemosus and R. oligosporus also contained rhamnose. In the EPS produced by Penicillium spp. and A. repens the galactose residues were determined to be immunodominant.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  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. 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

  17. Purification, properties and immunological relationship of L (+)-lactate dehydrogenase from Lactobacillus casei.

    Science.gov (United States)

    Gordon, G L; Doelle, H W

    1976-08-16

    The fructose-1,6-bisphosphate-activated L-lactate dehydrogenase (EC 1.1.1.27) from Lactobacillus casei ATCC 393 has been purified to homogenity by including affinity chromatography (cibacronblue-Sephadex-G-200) and preparative polyacrylamide gel electrophoresis into the purification procedures. The enzyme has an Mr of 132000-135000 with a subunit Mr of 34000. The pH optimum was found to be 5.4 insodium acetate buffer. Tris/maleate and citrate/phosphate buffers inhibited enzyme activity at this pH. The enzyme was completely inactivated by a temperature increase from 60 degrees C to 70 degrees C. Pyruvate saturation curves were sigmoidal in the absence of fructose 1,6-bisphosphate. In the presence of 20 muM fructose 1,6-bisphosphate a Km of 1.0 mM for pyruvate was obtained, whereas fructose 1,6-bisphosphate had no effect on the Km of 0.01 mM for NADH. The use of pyruvate analogues revealed two types of pyruvate binding sites, a catalytic and an effector site. The enzyme from L. casei appears to be subject to strict metabolic control, since ADP, ATP, dihydroxyacetone phosphate and 6-phosphogluconate are strong inhibitors. Immunodiffusion experiments with a rabbit antiserum to L. casei lactate dehydrogenase revealed that L. casei ATCC 393 L (+)-lactate dehydrogenase is probably not immunologically related to group D and group N streptococci. Of 24 lactic acid bacterial strains tested only 5 strains did cross-react: L. casei ATCC 393 = L. casei var. rhamnosus ATCC 7469 - L. casei var. alactosus NCDO 680 greater than L. casei UQM 95 greater than L. plantarum ATCC 14917.

  18. 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)

  19. 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)

  20. 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.

  1. Purification and properties of phosphoribosyl-diphosphate synthetase from Bacillus subtilis

    DEFF Research Database (Denmark)

    Arnvig, Kirsten; Hove-Jensen, Bjarne; Switzer, Robert L.

    1990-01-01

    enzyme required Mg2+ and inorganic phosphate for activity; Mn2+ supported only 30% the activity seen with Mg2+. Michaelis constants for ATP and ribose 5-phosphate (Rib5P) were 0.66 mM and 0.48 mM, respectively. Of several end products tested, only ADP was strongly inhibitory; GDP was a weak inhibitor....... ADP inhibition displayed homotropic cooperativity and was enhanced by increasing saturation of the enzyme with ATP. These observations strongly suggest a specific allosteric site for ADP binding. A comparison of physical and kinetic properties of bacterial and mammalian PPRibP synthetases is presented....

  2. Bidentate organophosphorus extractants: purification, properties and applications to removal of actinides from acidic waste solutions

    International Nuclear Information System (INIS)

    Schulz, W.W.; McIsaac, L.D.

    1977-05-01

    At both Hanford and Idaho, DHDECMP (dihexyl-N, N-diethylcarbamylmethylene phosphonate) continuous counter-current solvent extraction processes are being developed for removal of americium, plutonium, and, in some cases, other actinides from acidic wastes generated at these locations. Bench and, eventually, pilot and plant-scale testing and application of these processes have been substantially enhanced by the discovery of suitable chemical and physical methods of removing deleterious impurities from technical-grade DHDECMP. Flowsheet details, as well as various properties of purified DHDECMP extractants, are enumerated

  3. Dominant lactic acid bacteria and their technological properties isolated from the Himalayan ethnic fermented milk products.

    Science.gov (United States)

    Dewan, Sailendra; Tamang, Jyoti Prakash

    2007-10-01

    Ethnic people of the Himalayan regions of India, Nepal, Bhutan and China consume a variety of indigenous fermented milk products made from cows milk as well as yaks milk. These lesser-known ethnic fermented foods are dahi, mohi, chhurpi, somar, philu and shyow. The population of lactic acid bacteria (LAB) ranged from 10(7) to 10(8) cfu/g in these Himalayan milk products. A total of 128 isolates of LAB were isolated from 58 samples of ethnic fermented milk products collected from different places of India, Nepal and Bhutan. Based on phenotypic characterization including API sugar test, the dominant lactic acid bacteria were identified as Lactobacillus bifermentans, Lactobacillus paracasei subsp. pseudoplantarum, Lactobacillus kefir, Lactobacillus hilgardii, Lactobacillus alimentarius, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris and Enterococcus faecium. LAB produced a wide spectrum of enzymes and showed high galactosidase, leucine-arylamidase and phosphatase activities. They showed antagonistic properties against selected Gram-negative bacteria. None of the strains produced bacteriocin and biogenic amines under the test conditions used. Most strains of LAB coagulated skim milk with a moderate drop in pH. Some strains of LAB showed a high degree of hydrophobicity, suggesting these strains may have useful adhesive potential. This paper is the first report on functional lactic acid bacterial composition in some lesser-known ethnic fermented milk products of the Himalayas.

  4. Purification of cynarases from artichoke (Cynara scolymus L.): enzymatic properties of cynarase A.

    Science.gov (United States)

    Sidrach, Lara; García-Cánovas, Francisco; Tudela, José; Rodríguez-López, José Neptuno

    2005-01-01

    Aspartic proteinases from flowers of Cynara cardunculus have been extensively studied and long used as coagulants in the manufacture of several traditional Spanish and Portuguese cheeses. These endopeptidases are called cardosins or cynarases, depending on the authors. However, the proteinases of another plant of the genus Cynara, the artichoke (Cynara scolymus), are less known, probably because the flower of this plant is usually consumed as a vegetable. In the study described here, three proteinases (cynarases A, B and C) with milk-clotting properties were purified from the stigma of artichoke. All three proteinases are glycoproteins and composed of a one large and one small subunit. The enzymatic properties of cynarase A, a glycoprotein containing N-linked high mannose type glycans, which express maximum activity at pH 5.0 and 70 degrees C, were studied in detail. Catalytic and inhibition studies indicated that this cynarase is of the aspartic acid type. The results indicate artichoke extract could also be used in the milk industry in the same way as the extract obtained from the flower of C. cardunculus.

  5. Mosquitocidal and water purification properties of Ocimum sanctum and Phyllanthus emblica

    Directory of Open Access Journals (Sweden)

    Kadarkarai Murugan

    2012-12-01

    Full Text Available Ocimum sanctum was tested for its larvicidal and water sedimentation properties; the fruit ethanol and methanol extracts of Phyllanthus emblica were tested for phytochemical, larvicidal, oviposition-deterrent and ovicidal activities. Results emphasized that plant extracts have high toxicity against the egg and larvae of the malarial vector Anopheles stephensi and also have water sedimentation properties. LC50 of Phyllanthus emblica against Anopheles stephensi larvae ranged from 33.08 ppm to 81.26 ppm and from 23.44 to 54.19 ppm for ethanol and methanol extracts, respectively. Phyllanthus emblica also showed excellent ovipositional deterrent and ovicidal activities. The oviposition activity index value of ethanol and methanol extracts of Phyllanthus emblica at 500 ppm were -0.80 and -0.92, respectively. Ocimum sanctum includes both insecticidal secondary compounds, amino acids (glycine, lysine, vitamin C and other substances, that make treated water suitable for human consumption. Water quality parameters such as color, turbidity and pH were analyzed in the water samples (pre-treatment and post-treatment of plant extracts taken from the breeding sites of mosquitoes. Hence, the plant product can be used as both mosquitocidal and water purifier.

  6. Purification, structural characterization and anticoagulant properties of fucosylated chondroitin sulfate isolated from Holothuria mexicana.

    Science.gov (United States)

    Mou, Jiaojiao; Wang, Cong; Li, Wenjing; Yang, Jie

    2017-05-01

    A novel fucosylated chondroitin sulfate (HmG) was isolated from sea cucumber Holothuria mexicana, the structure of which was characterized by monosaccharide composition, disaccharide composition, IR, 1 H and 13 C NMR spectrum, additionally with two dimensional NMR spectrum of degraded HmG (DHmG). The backbone of HmG was identified as chondroitin 6-O sulfate, while the major O-4 sulfated fucose branches linked to O-3 position of glucuronic acid in almost every disaccharide unit. The anticoagulant activities of HmG and DHmG were assessed and compared with heparin and low molecular weight heparin. The results indicated that HmG and DHmG both could significantly prolong the activated partial thrombo-plastin time, and the properties were well related to its molecular weight. DHmG showed similar anticoagulant properties to low molecular weight heparin with less bleeding risks, making it a safer anticoagulant drug. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. 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.

  8. 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.)

  9. Purification and properties of asparaginase from the testa of immature seeds of pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Chagas Eliana P.

    2001-01-01

    Full Text Available A K+-dependent asparaginase (E.C. 3.5.1.1. was purified 1328-fold from the testas of immature pea seeds (Pisum sativum L., var. Bolero and characterized. Antibodies raised against purified asparaginase cross-reacted with the putative asparaginase band in Western blot analyses of semi-purified extracts. However, for crude extracts of pea testas, a cross-reaction was obtained with at least four protein bands, one of which was asparaginase protein. Affinity-purified antibodies to the four strongest bands of crude extracts were fairly specific for the bands from which they were purified, suggesting a mixture of specific antibodies. The Mr of asparaginase was 69,000 by Sephacryl S200 chromatography and also by mobility on native PAGE relative to BSA. There was no evidence for dissociation into subunits on SDS-PAGE, suggesting a monomeric protein of Mr 69,000. Other properties include an apparent Km of 2.4 mM, pI between 4.5 and 5, and competitive inhibition by aspartate and glycine.

  10. Purification and physicochemical properties of. cap alpha. -amylase from irradiated wheat

    Energy Technology Data Exchange (ETDEWEB)

    Machaiah, J P; Vakil, U K [Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.

    1981-06-01

    ..cap alpha..-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. ..cap alpha..-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 ..cap alpha..-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.

  11. PURIFICATION AND PROPERTIES OF A FUNGAL L-ASPARAGINASE FROM TRICHODERMA VIRIDE PERS: SF GREY

    Directory of Open Access Journals (Sweden)

    Lynette Lincoln

    2015-02-01

    Full Text Available A potent L-asparaginase-producing Trichoderma viride Pers: SF Grey was screened from the marine soil with the objective of studying the enzyme properties. The maximum enzyme production occurred on the third day at pH 6.5 and 37 °C when 0.5% L-asparagine supplemented with 0.5% peptone and 0.6% maltose. The enzyme was purified to homogeneity with a specific activity of 78.2 U.mg-1 and a molecular weight of 99 ± 1 kDa. It exhibited maximum activity at pH 7.0 and 37 °C. It was inhibited by Fe2+, Fe3+, Co2+ and Mn2+ but induced by Mg2+ and Na+. N-ethylemaleimide and phenylmethylsulphonylfluoride did not alter the enzyme activity, but strongly inhibited by ethylenediaminetetraacetate. L-asparaginase showed high affinity for L-asparagine with a Km of 2.56 μM. Thin layer chromatography confirmed the hydrolysis of L-asparagine. As the purified and characterized L-asparaginase of Trichoderma viride showed a good scavenging activity and reduced acrylamide level in potato products, it can further serve as an antileukemic protein and an acrylamide mitigation agent in heat-treated food stuffs rich in carbohydrates, respectively.

  12. Isolation and identification of local bacteria endophyte and screening of its antimicrobial property against pathogenic bacteria and fungi

    Science.gov (United States)

    Fikri, Ahmad Syairazie Ibrahim; Rahman, Irman Abdul; Nor, Norefrina Shafinaz Md; Hamzah, Ainon

    2018-04-01

    Endophytes are organisms, often fungi and bacteria that live in living plant cells. These organisms reside in the living tissues of the host plant in a variety of relationships, ranging from symbiotic to slightly pathogenic. The endophytes may produce a plethora of substances that have potential to be used in modern medicine, agriculture and industry. The aims of this study are to isolate, identify and screening antimicrobial activity of bacterial endophytes. The endophytes were isolated using nutrient agar, incubated at 37°C for 48 hours. Identification of the isolates were done based on morphological characteristics, biochemical tests and 16S rDNA molecular analysis. Disk diffusion method was used to screen for antimicrobial activity of metabolites from endophytes against pathogenic bacteria. Screening for antifungal activity of selected endophytes was done using dual culture method againts pathogenic fungi followed by Kirby-Bauer method. Results showed endophytes designated as B2c and B7b have positive antimicrobial activity. The metabolites from isolate B2c showed antimicrobial activity against pathogenic bacteria methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus and Staphylococcus epidermis, while isolate B7b have positive activities againts MRSA, S. aureus and Pseudomonas aeruginosa. Isolates B2c displayed antifungal activity against Fusarium oxysporum, Fusarium solani, Phytophthora palmivora and Colletotrichum gloeosporioides. Identification using biochemical tests and 16S rDNA sequences identified isolate B2c as Pseudomonas resinovorans with 97% homology and isolate B7b as Bacillus subtilis with 98% homology.

  13. Effect of self purification on the structural optical and electrical properties of copper doped oxidized Zn films

    International Nuclear Information System (INIS)

    Koshy, Obey; Abdul Khadar, M.

    2015-01-01

    The effect of self purification mechanism is studied on oxidized Cu–Zn thin films. Oxidized Cu–Zn thin films were prepared by thermal evaporation on glass substrates. XRD studies indicate that the oxidized Cu–Zn thin films are of hexagonal wurtzite structure. AFM images shows that with increase in copper wt. percent the nanoparticle morphology of oxidized Zn film turned to one dimensional nanorod morphology. XPS spectra of the oxidized Cu–Zn thin films shows the oxidized state of zinc and copper. The PL spectra of oxidized Zn film showed a strong and narrow near band edge emission at 380 nm whereas in the case of oxidized Cu–Zn thin films the emission showed peak near 410 nm corresponding to peak related to copper. With increase in copper content, the intensity of the defect emission decreased due to the self purification mechanism in nanomaterials. In addition the resistivity of doped films increased due to the self purification mechanism in nanomaterials. - Highlights: • Copper doping in ZnO resulted in the increase in blue emission due to defect levels formed. • The intensity of the luminescence peak of the doped film sample decreased and resistivity increased due to the self purification mechanism in nanomaterials.

  14. Antimicrobial Property of Extracts of Indian Lichen against Human Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Priya Srivastava

    2013-01-01

    Full Text Available Context. Usnea ghattensis G. Awasthi (Usneaceae endemic fruticose lichen found growing luxuriantly in Northern Western Ghats of India, it also contains Usnic acid as a major chemical and tested against some human pathogenic bacteria. Objective. To explore antimicrobial properties of Usnea ghattensis against some human pathogenic bacteria. Materials and Methods. The lichen was extracted in acetone, methanol, and ethanol. In vitro antimicrobial activity was tested initially by Kirby-Bauer technique of disc diffusion method and was confirmed by minimum inhibitory concentration using Broth microdilution method according to the NCCLS guidelines. Results. Ethanol extract was most effective against Bacillus cereus and Pseudomonas aeruginosa with a zone of inhibition 29.8 ± 0.6 mm and 12.3 ± 0.5 mm diameters at a concentration of 0.2 mg/mL. Acetone and methanol extract demonstrated almost similar activity against Staphylococcus aureus and the zone of inhibition was 24.6 ± 0.5 and 24.7 ± 0.4 mm. Only methanol extract was showing activity against Streptococcus faecalis with a 13.5 ± 0.8 mm zone. MIC value noted against Staphylococcus aureus and Streptococcus faecalis was 6.25 μg/mL and 25 μg/mL, whereas against Bacillus cereus and Pseudomonas aeruginosa, MIC calculated was 3.125 μg/mL and 200 μg/mL, respectively. Conclusion. The present study demonstrates the relatively higher activity of this lichen against not only gram (+ but significantly also against gram (− bacteria. This indicates that this lichen might be a rich source of effective antimicrobial agents.

  15. 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

  16. 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.

  17. A food-grade process for isolation and partial purification of bacteriocins of lactic acid bacteria that uses diatomite calcium silicate.

    Science.gov (United States)

    Coventry, M J; Gordon, J B; Alexander, M; Hickey, M W; Wan, J

    1996-01-01

    Bacteriocins, including nisin, pediocin PO2, brevicin 286, and piscicolin 126, were extracted from fermentation media by adsorption onto Micro-Cel (a food-grade diatomite calcium silicate anticaking agent) and subsequent desorption. The optimal conditions for desorption of piscicolin 126 were determined and applied to other bacteriocins, and the relative purities of the desorbed preparations were compared. Piscicolin was not successfully desorbed from Micro-Cel at pH 1.0 to 12.0, with organic solvents, or by increase of ionic strength up to 1 M NaCl. However, 25 and 75% of the bacteriocin activity was desorbed by using 1% sodium deoxycholate and 1% sodium dodecyl sulfate (SDS), respectively. Higher levels (up to 100%) of desorption were achieved by repeated elution or by an increase in surfactant concentration. Desorption of piscicolin with 1/10 volume of SDS solution resulted in a preparation with 10 times concentration in activity, equivalent to that of ammonium sulfate preparations (409,600 to 819,200 activity units/ml). Determination of organic nitrogen (N) content revealed that the desorbed piscicolin preparations were substantially free of proteinaceous substances (approximately 92 to 99%) compared with original culture supernatants and ammonium sulfate preparations. Nisin, pediocin, and brevicin were also desorbed with 1% SDS with a similar level of purification. PMID:8633875

  18. Functional properties of lactic acid bacteria isolated from ethnic fermented vegetables of the Himalayas.

    Science.gov (United States)

    Tamang, Jyoti Prakash; Tamang, Buddhiman; Schillinger, Ulrich; Guigas, Claudia; Holzapfel, Wilhelm H

    2009-09-30

    A total of 94 strains of Lactic acid bacteria (LAB), previously isolated from ethnic fermented vegetables and tender bamboo shoots of the Himalayas, were screened for functional properties such as acidification capacity, enzymatic activities, degradation of antinutritive factors and oligosaccharides, production of biogenic amines, hydrophobicity and adherence to mucus secreting HT29 MTX cells. Strong acidification and coagulation activities of LAB strains were recorded. Most of the LAB strains showed antimicrobial activities against the used indicator strains; however, only Lb. plantarum IB2 (BFE 948) isolated from inziangsang, a fermented leafy vegetable product, produced a bacteriocin against Staphylococcus aureus S1. LAB strains showed enzymatic activities and also degraded oligosaccharides. Almost all the strains of LAB were non-producers of biogenic amines except few strains. Some strains of Lb. plantarum showed more than 70% hydrophobicity. Adherence to the mucus secreting HT29 MTX cells was also shown by seven strains indicating their probiotic nature.

  19. 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.

  20. 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.

  1. 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

  2. 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

    2018-05-01

    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.

  3. 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.

  4. 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

  5. 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.

  6. 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)

  7. 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

  8. Cloning, overexpression, purification of bacteriocin enterocin-B and structural analysis, interaction determination of enterocin-A, B against pathogenic bacteria and human cancer cells.

    Science.gov (United States)

    Ankaiah, Dasari; Palanichamy, Esakkiraj; Antonyraj, Christian Bharathi; Ayyanna, Repally; Perumal, Venkatesh; Ahamed, Syed Ibrahim Basheer; Arul, Venkatesan

    2018-05-02

    In this present study, a gene (ent-B) encoding the bacteriocin enterocin-B was cloned, overexpressed and purified from Enterococcus faecium por1. The molecular weight of the bacteriocin enterocin-B was observed around 7.2 kDa and exhibited antimicrobial activity against several human pathogenic bacteria. The antimicrobial activity of cloned enterocin-B was increased effectively by combining with another bacteriocin enterocin-A from the same microorganism. Protein-protein docking and molecular dynamics simulation studies revealed that the bacteriocin enterocin-B is interacting with enterocin-A and formation of a heterodimer (enterocin A + B). The heterodimer of bacteriocin enterocin-A + B exhibited potential anti-bacterial, anti-biofilm activity against Staphylococcus aureus, Acinetobacter baumannii, Listeria monocytogenes and Escherichia coli. The bacteriocin enterocin-B, A and heterodimer of bacteriocin enterocin A + B showed no haemolysis on human RBC cells. This is the first report that the cell growth inhibitory activity of the bacteriocin enterocin B against HeLa, HT-29 and AGS human cancer cells and this cell growth inhibitory activity was significantly increased when cancer cells treated with the heterodimer of bacteriocins enterocin-A + B. The cell growth inhibitory activity of the bacteriocin enterocin-B and the heterodimer of bacteriocin enterocin-A + B were not observed in non-cancerous INT-407 cells (intestinal epithelial cells). Copyright © 2018. Published by Elsevier B.V.

  9. Phospholipase A2 from Bothrops alternatus (víbora de la cruz) venom. Purification and some characteristic properties.

    Science.gov (United States)

    Nisenbom, H E; Seki, C; Vidal, J C

    1986-01-01

    One single protein species with phospholipase activity has been isolated from Bothrops alternatus venom by a procedure involving gel-filtration on Sephadex G-50 (Step 1), chromatography on SP-Sephadex C-50 (Step 2) and gel-filtration on Sephadex G-75 (Step 3). The purified sample behaved as a homogeneous, monodisperse protein with a molecular weight of 15,000 and isoelectric point of 5.04. The yield in enzyme activity was 48% of the starting material and the apparent purification was 51-fold. When assayed on 1,2-diheptanoyl- or 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine, fatty acids and lysolecithins were the only reaction products, in accordance with the predicted stoichiometry. Studies on positional specificity suggested that the enzyme is a phospholipase A2. The enzyme requires Ca2+ ions for activity and exhibited stereochemical specificity, since the enantiomeric 2, 3-diheptanoyl-sn-glycero-1-phosphorylcholine was not hydrolyzed. Under the experimental conditions employed, reaction products representative of either phospholipase B or C activities could not be detected. After Step 1, the phospholipase activity recovered was higher than the total activity in the crude venom sample, which is explained by the separation of an inhibitor during enzyme purification. The inhibitor was responsible for the initial lag period that characterized the kinetics of the enzyme reaction with crude venom acting on aggregated substrates (lipoprotein, vesicles or micelles), while the rate of hydrolysis of monomeric lecithins was not affected.

  10. 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 ...

  11. The purification by ion exchange resins of the heavy water la the reactors EL1 and EL2. B - study of the general properties of the resins used

    International Nuclear Information System (INIS)

    Fourre; Platzer

    1957-01-01

    Within the programme of the pile heavy water purification project, organized by the stable Isotopes Section, we have carried out a certain number of tests on ion exchange resins. The problem posed by the stable Isotopes Section was to determine the conditions of utilisation of ion exchange resins, knowing that they would be employed in a system branching off the heavy water circuit in the piles. These investigations were carried out in close collaboration with the stable Isotopes Section, and were guided chiefly by the extremely short delay permitted between the laboratory study and its application to the piles. The tests are divided into two groups: 1- General properties of the resins. 2- Utilisation of the resins, particularly in an apparatus similar to those mounted on the piles but of smaller dimensions. (author) [fr

  12. Investigation of the Surface Properties of an Oxide of Interest in the Field of a Conductive Oxide System: Influence of Precursor and Purification

    Directory of Open Access Journals (Sweden)

    Gomes Gilmar de Almeida

    1999-01-01

    Full Text Available The surface properties of commercial TiO2 and samples synthesized by the thermal decomposition procedure using several precursor salts were investigated by a microelectrophoresis technique. The iep was determined as a function of the ionic strength which was controlled with KNO3 or KCl. The experimental results showed: 1 The commercial sample and the ones synthesized from the chloride salt dissolved in HCl 1:1 (v/v show low iep?s due to chloride inclusion; 2 The purification methods explored (oxide suspension at pH~12 and dialysis are inefficient; 3 TiO2 samples synthesized from an organic precursor salt under totally chloride-free conditions furnished an iep of 5.9 in excellent agreement with literature data; 4 Chloride specific adsorption on TiO2 is weak.

  13. 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)

  14. 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.

  15. 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.

  16. 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.

  17. 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.

    unicellular cyanobacterium Synechocystis sp. that came from a heavy metal contaminated region of Cochin estuary, southwest coast of India. Based on 16S rRNA gene sequence similarities, the heterotrophic bacteria were grouped into three phyla: namely...

  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. 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.

  20. 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.

  1. 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

  2. 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

  3. Purification and properties of the glutathione S-transferases from the anoxia-tolerant turtle, Trachemys scripta elegans.

    Science.gov (United States)

    Willmore, William G; Storey, Kenneth B

    2005-07-01

    Glutathione S-transferases (GSTs) play critical roles in detoxification, response to oxidative stress, regeneration of S-thiolated proteins, and catalysis of reactions in nondetoxification metabolic pathways. Liver GSTs were purified from the anoxia-tolerant turtle, Trachemys scripta elegans. Purification separated a homodimeric (subunit relative molecular mass =34 kDa) and a heterodimeric (subunit relative molecular mass = 32.6 and 36.8 kDa) form of GST. The enzymes were purified 23-69-fold and 156-174-fold for homodimeric and heterodimeric GSTs, respectively. Kinetic data gathered using a variety of substrates and inhibitors suggested that both homodimeric and heterodimeric GSTs were of the alpha class although they showed significant differences in substrate affinities and responses to inhibitors. For example, homodimeric GST showed activity with known alpha class substrates, cumene hydroperoxide and p-nitrobenzylchloride, whereas heterodimeric GST showed no activity with cumene hydroperoxide. The specific activity of liver GSTs with chlorodinitrobenzene (CDNB) as the substrate was reduced by 2.6- and 8.7-fold for homodimeric and heterodimeric GSTs isolated from liver of anoxic turtles as compared with aerobic controls, suggesting an anoxia-responsive stable modification of the protein that may alter its function during natural anaerobiosis.

  4. One-step FPLC-size-exclusion chromatography procedure for purification of rDMBT1 6 kb with increased biological activity

    DEFF Research Database (Denmark)

    Tuttolomondo, Martina; Hansen, Pernille Lund; Mollenhauer, Jan

    2018-01-01

    from saliva or produced in vitro and purified by a multistep affinity purification procedure using bacteria, followed by FPLC. Here, we compared a simple, one-step FPLC-SEC protocol for purification of recombinant DMBT1 6 kb, with that of the standard bacteria affinity purification-based protocol. Our...

  5. 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.

  6. Separation, Purification and Identification of Bacteria

    African Journals Online (AJOL)

    user

    2011-05-16

    May 16, 2011 ... vulnerable to contamination by microorganisms when worn. Some published ... conical flask with glass beads and 100 ml sterile water was added ... Jintan Fuhua Instrument Co., China) at 200 rpm for 3 h to disperse the cells ...

  7. Purification and properties of glutathione reductase from liver of the anoxia-tolerant turtle, Trachemys scripta elegans.

    Science.gov (United States)

    Willmore, William G; Storey, Kenneth B

    2007-03-01

    Glutathione reductase (GR) is a homodimeric flavoprotein that catalyzes the reduction of oxidized glutathione (GSSG) using NADPH as a cofactor. The enzyme is a major component of cellular defense mechanisms against oxidative injury. In this study, GR was purified from the liver of the anoxia-tolerant turtle, Trachemys scripta elegans. The overall fold purifications were 13.3- and 12.1-fold with final specific activities of 5.5 and 1.44 U/mg of protein for control and anoxic turtle GR, respectively. SDS-PAGE of purified turtle liver GR showed a single protein band at approximately 55 kDa. Reverse phase HPLC of turtle GR revealed a single peak that had the same retention time as yeast GR. No new isoform of GR was detected in liver of T. s. elegans during anoxia. The K (m) values of turtle GR for GSSG and NADPH was 44.6 and 6.82 microM, respectively, suggesting a substantially higher affinity of turtle GR toward GSSG than most other vertebrates. Unlike other human GR, NADP(+ )did not inhibit turtle GR activity. The activation energy of turtle GR, calculated from the slope of the Arrhenius plot, was 32.2 +/- 2.64 kJ/mol. Turtle GR had high activity under a broad pH range (having activity between pHs 4 and 10; optimal activity at pH 6.5) and the enzyme maintains activity under the pH drop that occurs under anoxic conditions. The high affinity of turtle GR suggests that turtles have high redox buffering capacity of tissues to protect against oxidative stress encountered during anoxia/reoxygenation.

  8. 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.

  9. Diversity, metabolic properties and arsenic mobilization potential of indigenous bacteria in arsenic contaminated groundwater of West Bengal, India.

    Science.gov (United States)

    Paul, Dhiraj; Kazy, Sufia K; Gupta, Ashok K; Pal, Taraknath; Sar, Pinaki

    2015-01-01

    Arsenic (As) mobilization in alluvial aquifers is caused by a complex interplay of hydro-geo-microbiological activities. Nevertheless, diversity and biogeochemical significance of indigenous bacteria in Bengal Delta Plain are not well documented. We have deciphered bacterial community compositions and metabolic properties in As contaminated groundwater of West Bengal to define their role in As mobilization. Groundwater samples showed characteristic high As, low organic carbon and reducing property. Culture-independent and -dependent analyses revealed presence of diverse, yet near consistent community composition mostly represented by genera Pseudomonas, Flavobacterium, Brevundimonas, Polaromonas, Rhodococcus, Methyloversatilis and Methylotenera. Along with As-resistance and -reductase activities, abilities to metabolize a wide range carbon substrates including long chain and polyaromatic hydrocarbons and HCO3, As3+ as electron donor and As5+/Fe3+ as terminal electron acceptor during anaerobic growth were frequently observed within the cultivable bacteria. Genes encoding cytosolic As5+ reductase (arsC) and As3+ efflux/transporter [arsB and acr3(2)] were found to be more abundant than the dissimilatory As5+ reductase gene arrA. The observed metabolic characteristics showed a good agreement with the same derived from phylogenetic lineages of constituent populations. Selected bacterial strains incubated anaerobically over 300 days using natural orange sand of Pleistocene aquifer showed release of soluble As mostly as As3+ along with several other elements (Al, Fe, Mn, K, etc.). Together with the production of oxalic acid within the biotic microcosms, change in sediment composition and mineralogy indicated dissolution of orange sand coupled with As/Fe reduction. Presence of arsC gene, As5+ reductase activity and oxalic acid production by the bacteria were found to be closely related to their ability to mobilize sediment bound As. Overall observations suggest that

  10. 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

  11. Antimicrobial property of lemongrass (Cymbopogon citratus) oil against pathogenic bacteria isolated from pet turtles.

    Science.gov (United States)

    De Silva, B C J; Jung, Won-Gi; Hossain, Sabrina; Wimalasena, S H M P; Pathirana, H N K S; Heo, Gang-Joon

    2017-06-01

    The usage of essential oils as antimicrobial agents is gaining attention. Besides, pet turtles were known to harbor a range of pathogenic bacteria while the turtle keeping is a growing trend worldwide.The current study examined the antimicrobial activity of lemon grass oil (LGO) against seven species of Gram negative bacteria namely; Aeromonas hydrophila , A. caviae , Citrobacter freundii , Salmonella enterica , Edwardsiella tarda , Pseudomonas aeruginosa , and Proteus mirabilis isolated from three popular species of pet turtles. Along with the results of disc diffusion, minimum inhibitory and minimum bactericidal concentration (MIC and MBC) tests, LGO was detected as effective against 6 species of bacteria excluding P. aeruginosa . MIC of LGO for the strains except P. aeruginosa ranged from 0.016 to 0.5% (V/V). The lowest MIC recorded in the E. tarda strain followed by A. hydrophilla , C. freundii , P. mirabilis , and S. enterica . Interestingly, all the bacterial species except E. tarda were showing high multiple antimicrobial resistance (MAR) index values ranging from 0.36 to 0.91 upon the 11 antibiotics tested although they were sensitive to LGO.

  12. Properties and biotechnological applications of ice-binding proteins in bacteria.

    Science.gov (United States)

    Cid, Fernanda P; Rilling, Joaquín I; Graether, Steffen P; Bravo, Leon A; Mora, María de La Luz; Jorquera, Milko A

    2016-06-01

    Ice-binding proteins (IBPs), such as antifreeze proteins (AFPs) and ice-nucleating proteins (INPs), have been described in diverse cold-adapted organisms, and their potential applications in biotechnology have been recognized in various fields. Currently, both IBPs are being applied to biotechnological processes, primarily in medicine and the food industry. However, our knowledge regarding the diversity of bacterial IBPs is limited; few studies have purified and characterized AFPs and INPs from bacteria. Phenotypically verified IBPs have been described in members belonging to Gammaproteobacteria, Actinobacteria and Flavobacteriia classes, whereas putative IBPs have been found in Gammaproteobacteria, Alphaproteobacteria and Bacilli classes. Thus, the main goal of this minireview is to summarize the current information on bacterial IBPs and their application in biotechnology, emphasizing the potential application in less explored fields such as agriculture. Investigations have suggested the use of INP-producing bacteria antagonists and AFPs-producing bacteria (or their AFPs) as a very attractive strategy to prevent frost damages in crops. UniProt database analyses of reported IBPs (phenotypically verified) and putative IBPs also show the limited information available on bacterial IBPs and indicate that major studies are required. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. 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.

  14. Isolation, purification and physicochemical properties of polysaccharide from fruiting body of Hericium erinaceus and its effect on colonic health of mice.

    Science.gov (United States)

    Wang, Xiao-Yin; Yin, Jun-Yi; Nie, Shao-Ping; Xie, Ming-Yong

    2018-02-01

    Hericium erinaceus was extracted with boiling water to obtain the crude polysaccharide (HECP) and refined polysaccharide (HERP). HERP was further purified using gradual ethanol precipitation to obtain five sub-fractions. Their physicochemical properties were evaluated, including chemical components, monosaccharide composition and molecular weight. Meanwhile, the effect of HERP on colonic health of mice was investigated by oral administration at dosages of 100, 200 and 400mg/kg of body weight (mg/kgbw), comparing with that of HECP. Results showed that the gradual ethanol precipitation could remarkably increase polysaccharide purity. HERP, HECP and the five purified fractions had different monosaccharide compositions, while the main monosaccharides were Glc and Gal. They all showed similar structure with amorphous appearance. Short-chain fatty acids productions in colonic and cecum contents, and feces of mice were increased in polysaccharide treated groups. Mice administrated with HERP at 400mg/kgbw showed significant reductions in pH values while obvious increases in moisture amounts. This study suggests that gradual ethanol precipitation is available for purification of polysaccharide from Hericium erinaceus and the extracted polysaccharide could improve colonic health. Copyright © 2017. Published by Elsevier B.V.

  15. Purification and properties of an O-acetyl-transferase from Escherichia coli that can O-acetylate polysialic acid sequences

    International Nuclear Information System (INIS)

    Higa, H.; Varki, A.

    1986-01-01

    Certain strains of bacteria synthesize an outer polysialic acid (K1) capsule. Some strains of K1 + E.coli are also capable of adding O-acetyl-esters to the exocyclic hydroxyl groups of the sialic acid residues. Both the capsule and the O-acetyl modification have been correlated with differences in antigenicity and pathogenicity. The authors have developed an assay for an O-acetyl-transferase in E.coli that transfers O-[ 3 H]acetyl groups from [ 3 H]acetyl-Coenzyme A to colominic acid (fragments of the polysialic acid capsule). Using this assay, the enzyme was solubilized, and purified ∼ 600-fold using a single affinity chromatography step with Procion Red-A Agarose. The enzyme also binds to Coenzyme A Sepharose, and can be eluted with high salt or Coenzyme A. The partially purified enzyme has a pH optimum of 7.0 - 7.5, is unaffected by divalent cations, is inhibited by high salt concentrations, is inhibited by Coenzyme A (50% inhibition at 100 μM), and shows an apparent Km for colominic acid of 3.7 mM (sialic acid concentration). This enzyme could be involved in the O-acetyl +/- form variation seen in some strains of K1 + E.coli

  16. Characterisation and biochemical properties of predominant lactic acid bacteria from fermenting cassava for selection as starter cultures.

    Science.gov (United States)

    Kostinek, M; Specht, I; Edward, V A; Pinto, C; Egounlety, M; Sossa, C; Mbugua, S; Dortu, C; Thonart, P; Taljaard, L; Mengu, M; Franz, C M A P; Holzapfel, W H

    2007-03-20

    A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains of facultatively heterofermentative rods, obligately heterofermentative rods, heterofermentative cocci, homofermentative cocci and obligately homofermentative rods, in decreasing order of predominance. Most of the facultatively heterofermentative rods were identified by phenotypic tests as presumptive Lactobacillus plantarum-group strains, which also comprised the most predominant bacteria (54.4% of strains) isolated in the study. The next predominant group of lactic acid bacteria (14.1% of total isolates) consisted of obligately heterofermentative rods belonging either to the genus Lactobacillus or Weissella, followed by the heterofermentative cocci (13.9% of isolates) belonging to the genera Weissella or Leuconostoc. Homofermentative cocci were also isolated (13.3% of isolates). Biochemical properties such as production of alpha-amylase, beta-glucosidase, tannase, antimicrobials (presumptive bacteriocin and H(2)O(2)-production), acidification and fermentation of the indigestible sugars raffinose and stachyose, were evaluated in vitro for selection of potential starter strains. A total of 32 strains with one or more desirable biochemical properties were pre-selected and identified using rep-PCR fingerprinting in combination with 16S rRNA sequencing of representative rep-PCR cluster isolates. Of these strains, 18 were identified as L. plantarum, four as Lactobacillus pentosus, two each as Leuconostoc fallax, Weissella paramesenteroides and Lactobacillus fermentum, one each as Leuconostoc mesenteroides subsp. mesenteroides and Weissella cibaria, while two remained unidentified but could be assigned to the L. plantarum-group. These strains were further investigated for clonal relationships, using RAPD-PCR with three primers, and of

  17. Modeling Bacteria Surface Acid-Base Properties: The Overprint Of Biology

    Science.gov (United States)

    Amores, D. R.; Smith, S.; Warren, L. A.

    2009-05-01

    Bacteria are ubiquitous in the environment and are important repositories for metals as well as nucleation templates for a myriad of secondary minerals due to an abundance of reactive surface binding sites. Model elucidation of whole cell surface reactivity simplifies bacteria as viable but static, i.e., no metabolic activity, to enable fits of microbial data sets from models derived from mineral surfaces. Here we investigate the surface proton charging behavior of live and dead whole cell cyanobacteria (Synechococcus sp.) harvested from a single parent culture by acid-base titration using a Fully Optimized ContinUouS (FOCUS) pKa spectrum method. Viability of live cells was verified by successful recultivation post experimentation, whereas dead cells were consistently non-recultivable. Surface site identities derived from binding constants determined for both the live and dead cells are consistent with molecular analogs for organic functional groups known to occur on microbial surfaces: carboxylic (pKa = 2.87-3.11), phosphoryl (pKa = 6.01-6.92) and amine/hydroxyl groups (pKa = 9.56-9.99). However, variability in total ligand concentration among the live cells is greater than those between the live and dead. The total ligand concentrations (LT, mol- mg-1 dry solid) derived from the live cell titrations (n=12) clustered into two sub-populations: high (LT = 24.4) and low (LT = 5.8), compared to the single concentration for the dead cell titrations (LT = 18.8; n=5). We infer from these results that metabolic activity can substantively impact surface reactivity of morphologically identical cells. These results and their modeling implications for bacteria surface reactivities will be discussed.

  18. 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 (pgenerator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed.

  19. 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.

  20. 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.

  1. 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.

  2. Dielectrophoresis-based discrimination of bacteria at the strain level based on their surface properties.

    Directory of Open Access Journals (Sweden)

    William A Braff

    Full Text Available Insulator-based dielectrophoresis can be used to manipulate biological particles, but has thus far found limited practical applications due to low sensitivity. We present linear sweep three-dimensional insulator-based dielectrophoresis as a considerably more sensitive approach for strain-level discrimination bacteria. In this work, linear sweep three-dimensional insulator-based dielectrophoresis was performed on Pseudomonas aeruginosa PA14 along with six isogenic mutants as well as Streptococcus mitis SF100 and PS344. Strain-level discrimination was achieved between these clinically important pathogens with applied electric fields below 10 V/mm. This low voltage, high sensitivity technique has potential applications in clinical diagnostics as well as microbial physiology research.

  3. Strong linkages between DOM optical properties and main clades of aquatic bacteria

    DEFF Research Database (Denmark)

    Amaral, Valentina; Graeber, Daniel; Calliari, Danilo

    2016-01-01

    –emission fluorescence spectroscopy and spectroscopic indexes to characterize DOM composition, and fluorescence in situ hybridization, to quantify the major bacterial groups in a subtropical lagoon. The DOM exhibited marked temporal variations in concentration, molecular weight, aromaticity, color, degree...... properties. Alphaproteobacteria and Gammaproteobacteria abundances were significantly explained by low or high dissolved organic carbon concentrations, respectively. The significant relationships between DOM properties and the main bacterial groups delineated a profile of each group regarding DOM preferences...

  4. 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.

  5. Mosquitocidal and water purification properties of Cynodon dactylon, Aloe vera, Hemidesmus indicus and Coleus amboinicus leaf extracts against the mosquito vectors.

    Science.gov (United States)

    Arjunan, Nareshkumar; Murugan, Kadarkarai; Madhiyazhagan, Pari; Kovendan, Kalimuthu; Prasannakumar, Kanagarajan; Thangamani, Sundaram; Barnard, Donald R

    2012-04-01

    Ethanolic extracts of Cynodon dactylon, Aloe vera, Hemidesmus indicus and Coleus amboinicus were tested for their toxicity effect on the third-instar larvae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The leaves of C. dactylon, A. vera, H. indicus and C. amboinicus were collected from natural habitats (forests) in Western Ghats, Tamil Nadu, India. A total of 250 g of fresh, mature leaves were rinsed with distilled water and dried in shade. The dried leaves were put in Soxhlet apparatus and extract prepared using 100% ethanol for 72 h at 30-40°C. Dried residues were obtained from 100 g of extract evaporated to dryness in rotary vacuum evaporator. Larvicidal properties of ethanolic leaf extracts showed that the extracts are effective as mosquito control agents. The larval mortality was observed after 24 h exposure. No mortality was observed in the control. The median lethal concentration (LC(50)) values observed for the larvicidal activities are 0.44%, 0.51%, 0.59% and 0.68% for extracts of C. dactylon, A. vera, H. indicus and C. amboinicus, respectively. The observed mortality were statistically significant at P < 0.05 level. C. dactylon showed the highest mortality rate against the three species of mosquito larvae in laboratory and field. The selected plants were shown to exhibit water purification properties. Water quality parameters such as turbidity, pH and water clarity were analyzed in the water samples (pre-treatment and post-treatment of plant extracts) taken from the different breeding sites of mosquitoes. Water colour, turbidity and pH were reduced significantly after treatment with C. dactylon (13 HU, 31.5 mg/l and 6.9), H. indicus (13.8 HU, 33 mg/l and 7.1), A. vera (16 HU, 33.8 mg/l and 7.4) and C. amboinicus (21 HU, 35 mg/l and 7.5) extracts. The study proved that the extracts of C. dactylon, A. vera, H. indicus and C. amboinicus have both mosquitocidal and water sedimentation properties.

  6. Plant nucleoside 5'-phosphoramidate hydrolase; simple purification from yellow lupin (Lupinus luteus) seeds and properties of homogeneous enzyme.

    Science.gov (United States)

    Guranowski, Andrzej; Wojdyła, Anna M; Rydzik, Anna M; Stepiński, Janusz; Jemielity, Jacek

    2011-01-01

    Adenosine 5'-phosphoramidate (NH₂-pA) is an uncommon natural nucleotide of poorly understood biochemistry and function. We studied a plant enzyme potentially involved in the catabolism of NH₂-pA. A fast and simple method comprising extraction of yellow lupin (Lupinus luteus) seed-meal with a low ionic strength buffer, ammonium sulfate and acetone fractionations, removal of contaminating proteins by heat denaturation, and affinity chromatography on AMP-agarose, yielded homogenous nucleoside 5'-phosphoramidase. Mass spectrometric analysis showed that the lupin hydrolase exhibits closest similarity to Arabidopsis thaliana Hint1 protein. The substrate specificity of the lupin enzyme, in particular its ability to split the P-S bond in adenosine 5'-phosphorothioate, is typical of known Hint1 proteins. Adenosine 5'-phosphofluoride and various derivatives of guanosine 5'-phosphoramidate were also substrates. Neither common divalent metal cations nor 10 mM EDTA or EGTA affected the hydrolysis of NH₂-pA. The enzyme functions as a homodimer (2 x 15,800 Da). At the optimum pH of 7.0, the K(m) for NH₂-pA was 0.5 µM and k(cat) 0.8 s⁻¹ (per monomer active site). The properties of the lupin nucleoside 5'-phosphoramidase are compared with those of its counterparts from other organisms.

  7. Purification and properties of a beta-galactosidase from carambola fruit with significant activity towards cell wall polysaccharides.

    Science.gov (United States)

    Balasubramaniam, Sumathi; Lee, Heng Chin; Lazan, Hamid; Othman, Roohaida; Ali, Zainon Mohd

    2005-01-01

    beta-Galactosidase (EC. 3.2.1.23) from ripe carambola (Averrhoa carambola L. cv. B10) fruit was fractionated through a combination of ion exchange and gel filtration chromatography into four isoforms, viz. beta-galactosidase I, II, III and IV. This beta-galactosidases had apparent native molecular masses of 84, 77, 58 and 130 kDa, respectively. beta-Galactosidase I, the predominant isoform, was purified to electrophoretic homogeneity; analysis of the protein by SDS-PAGE revealed two subunits with molecular masses of 48 and 36 kDa. N-terminal amino acid sequence of the respective polypeptides shared high similarities albeit at different domains, with the deduced amino acid sequence of certain plant beta-galactosidases, thus, explaining the observed low similarity between the two subunits. beta-Galactosidase I was probably a heterodimer that have glycoprotein properties and a pI value of 7.2, with one of the potential glycosylation sites appeared to reside within the 48-kDa-polypeptide. The purified beta-galactosidase I was substantially active in hydrolyzing (1-->4)beta-linked spruce and a mixture of (1-->3)beta- and (1-->6)beta-linked gum arabic galactans. This isoform also had the capability to solubilize and depolymerize structurally intact pectins as well as to modify alkaline-soluble hemicelluloses, reflecting in part changes that occur during ripening.

  8. 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.

  9. 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.

  10. 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

  11. [Experimental interaction of halophilic prokaryotes and opportunistic bacteria in brine].

    Science.gov (United States)

    Selivanova, E A; Nemtseva, N V

    2013-01-01

    Study the effect of extremely halophilic archaea and moderately halophilic bacteria on preservation of opportunistic bacteria in brine. 17 strains of moderately halophilic bacteria and 2 strains of extremely halophilic archaea were isolated from continental hypersaline lake Razval of Sol-Iletsk area of Orenburg Region. Identification of pure cultures of prokaryotes was carried out taking into account their phenotype properties and based on determination of 16S RNA gene sequence. The effect of halophilic prokaryote on elimination of Escherichia coli from brine was evaluated during co-cultivation. Antagonistic activity of cell extracts of the studied microorganisms was evaluated by photometric method. A more prolonged preservation of an E. coli strain in brine in the presence of live cells of extremely halophilic archaea Halorubrum tebenquichense and moderately halophilic bacteria Marinococcus halophilus was established. Extracts of cells of extremely halophilic archaea and moderately halophilic bacteria on the contrary displayed antagonistic activity. The protective effect of live cells of halophilic prokaryotes and antagonistic activity of their cell extracts change the period of conservation of opportunistic bacteria in brine that regulates inter-microbial interactions and changes the period of self-purification that reflects the sanitary condition of a hypersaline water body.

  12. Anaerobic bacteria

    Science.gov (United States)

    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  13. 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.

  14. Technological properties of bacteriocin-producing lactic acid bacteria isolated from Pico cheese an artisanal cow's milk cheese.

    Science.gov (United States)

    Ribeiro, S C; Coelho, M C; Todorov, S D; Franco, B D G M; Dapkevicius, M L E; Silva, C C G

    2014-03-01

    Evaluate technologically relevant properties from bacteriocin-producing strains to use as starter/adjunct cultures in cheese making. Eight isolates obtained from Pico cheese produced in Azores (Portugal) were found to produce bacteriocins against Listeria monocytogenes and three isolates against Clostridium perfringens. They were identified as Lactococcus lactis and Enterococcus faecalis and submitted to technological tests: growth at different conditions of temperature and salt, acid production, proteolysis, lipolysis, coexistence, enzymatic profile and autolytic capacity. Safety evaluation was performed by evaluating haemolytic, gelatinase and DNase activity, resistance to antibiotics and the presence of virulence genes. Some isolates presented good technological features such as high autolytic activity, acid and diacetyl production. Lactococcus lactis was negative for all virulence genes tested and inhibit the growth of all Lactic acid bacteria (LAB) isolates. Enterococci were positive for the presence of some virulence genes, but none of the isolates were classified as resistant to important antibiotics. The bacteriocin-producing Lc. lactis present good potential for application in food as adjunct culture in cheese production. The study also reveals good technological features for some Enterococcus isolates. Bacteriocin-producing strains presented important technological properties to be exploited as new adjunct culture for the dairy industry, influencing flavour development and improve safety. © 2013 The Society for Applied Microbiology.

  15. 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

  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 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.

  18. 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.

  19. Antibacterial Properties of Endophytic Bacteria Isolated from a Fern Species Equisetum arvense L. Against Foodborne Pathogenic Bacteria Staphylococcus aureus and Escherichia coli O157:H7.

    Science.gov (United States)

    Das, Gitishree; Patra, Jayanta Kumar; Baek, Kwang-Hyun

    2017-01-01

    Endophytic bacteria (EB) are a rich source of secondary metabolites with medicinal importance. In this study, EB were isolated from the bottle brush herb Equisetum arvense and identified based on 16S rRNA sequencing. Evaluation of its antibacterial potential was conducted using two common foodborne pathogenic bacteria, Staphylococcus aureus ATCC 12600 and Escherichia coli O157:H7 ATCC 43890. Out of 103 identified EB, three species, Streptomyces albolongus, Dermacoccus sp., and Mycobacterium sp., showed significant antibacterial activity against S. aureus with inhibition zones of 45.34 ± 0.15, 43.28 ± 0.19, and 22.98 ± 0.18 mm, respectively, whereas only two species, Streptomyces griseoaurantiacus (EAL196) and Paenibacillus sp. (EAS116), showed moderate antibacterial activity against E. coli O157:H7 with inhibition zones of 9.41 ± 0.29 and 10.44 ± 0.31 mm, respectively. Furthermore, ethyl acetate extract of S. albolongus, Mycobacterium sp., and Dermacoccus sp. showed antibacterial activity against S. aureus, with inhibition zones of 23.43 ± 0.21, 21.18 ± 0.22, and 19.72 ± 0.10 mm, respectively. The methanol extract of Dermacoccus sp. and Paenibacillus sp. showed antibacterial activity against S. aureus and E. coli O157:H7, with inhibition zones of 11.30 ± 0.17 and 10.01 ± 0.21 mm, respectively. Scanning electron microscopy indicated swollen and lysed cell membranes of pathogens treated with ethyl acetate extract. A possible reason might be, likely due to EB metabolites penetrating the bacterial cell membranes and affecting various metabolic functions resulting in lysis. To the best of our knowledge, this is the first study to report that EB from E. arvense can be used as a source of natural antibacterial compounds against foodborne pathogenic bacteria.

  20. 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.

  1. Laboratory of minerals purification

    International Nuclear Information System (INIS)

    2002-01-01

    The laboratory of minerals purification was organized in 1962 where with application of modern physical and chemical methods were investigated the mechanism of flotation reagents interaction with minerals' surface, was elaborated technologies on rising complexity of using of republic's minerals

  2. Cadmium purification with a vibrating reactor

    International Nuclear Information System (INIS)

    Torres, N.; Esna-Ashari, M.; Biallas, H.; Kangas, K.

    1986-01-01

    While electrolytically producing zinc from sulfide concentrates, purification is the most significant step. Impurities such as Co, Sn, Ge, Ni and Sb can cause extensive redissolution of the electrodeposited zinc, thus diminishing current efficiency. Other metals, particularly cadmium, lead and copper, can negatively affect zinc properties by deposition on the cathode. It is standard practice to use atomized zinc dust as a reducing agent in the purification process, either alone or combined with additives. In conventional operations, special facilities are necessary to produce zinc dust in an amount close to 8wt% of cathode production. This paper examines a technique which makes use of zinc granules instead of dust

  3. Purification and characterization of a protease from Thermophilic ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-19

    Oct 19, 2006 ... protein liquid chromatography. The method gave a ... gent industry are the proteases from bacteria sources ... In this paper, we report our recent progress on the purification ... 10 to 60 min, then cooled in ice-water and the residue activity was measured .... Huo P, Mao J, Shi Y (2003). ... Kumar CG (2002).

  4. 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.

  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. 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

  7. [Purification of human goose-type lysozyme 2 (HLysG2) from human seminal plasma and analysis of its enzymatic properties].

    Science.gov (United States)

    Huang, Peng; Yang, Zhifang; Bao, Jianying; Zhang, Ning; Li, Wenshu

    2017-03-01

    Objective To purify human goose-type lysozyme 2 (HLysG2) from human seminal plasma by chromatography and analyze its enzymatic properties. Methods The distribution of HLysG2 in semen was analyzed by Western blot analysis. Seminal plasma was subjected to the separation of target protein using cation-exchange chromatography, chitin affinity chromatography and size-exclusion chromatography. The purified product was identified by Western blot analysis and mass spectrometry (MS).The purity was analyzed by high performance liquid chromatography (HPLC). Then, the optimum pH, ion concentration and temperature of HLysG2 and its standard activity were determined by the turbidimetric assay. The bactericidal activity of HLysG2 was assessed by the colony-forming assay. Results The existence of HLysG2 in seminal plasma was confirmed by Western blot analysis. A protein of about 21.5 kDa was purified from seminal plasma by the three kinds of chromatography and identified as HLysG2 by Western blot analysis and MS. The final purity of the purified product was above 99.0% and the peak enzymatic activity reached 13 800 U/mg under the condition of pH 6.4, 0.09 mol/L Na + , 30DegreesCelsius. In vitro assay indicated that HLysG2 had a significant killing effect on Micrococcus lysodeikticus, Bacillus subtilis and Staphylococcus aureus, but not on Pseudomonas aeruginosa and Escherichia coli. Conclusion Native HLysG2 can be obtained from seminal plasma by chromatography. It has in vitro bactericidal activity against Gram-positive bacteria, suggesting that it might play a role in innate immunity of the male reproductive system.

  8. 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...... substrate were attacked most rapidly and their hydrolyses were stimulated by Ca2+. The 2-naphthylamide derivatives of neutral and basic amino acids were also hydrolysed by aminopeptidase A, but at rates about two orders of magnitude lower, and Ca2+ was inhibitory. The possibility that these atypical...

  9. [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

  10. Characterisation and biochemical properties of predominant lactic acid bacteria from fermenting cassava for selection as starter cultures

    CSIR Research Space (South Africa)

    Kostinek, M

    2007-03-01

    Full Text Available A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains...

  11. Evaluation of bean and soy tempeh influence on intestinal bacteria and estimation of antibacterial properties of bean tempeh.

    Science.gov (United States)

    Kuligowski, Maciej; Jasińska-Kuligowska, Iwona; Nowak, Jacek

    2013-01-01

    In this study the effect of bean tempeh on the growth of Bacillus subtilis, Escherichia coli, Lactobacillus acidophilus and Lactobacillus paracasei bacteria was investigated. Antibacterial activity was observed only in relation to the bacteria Bacillus subtilis. The effect of tempeh products on human intestinal microflora was also assessed. Bean and soy tempeh were culinarily processed and next digested in conditions simulating the human digestive tract (one of the digestive tracts was equipped with a mechanism simulating absorption). Soy tempeh stimulated most the growth of bacteria of the genus Bifidobacterium, while bean tempeh that of Escherichia coli. Using simulation of absorption for the digestion of fried soy tempeh resulted in a higher rise in the bacteria count of the genus Lactobacillus, while after digestion of fried bean tempeh the highest increase was recorded for Bifidobacterium and E. coli.

  12. Effects of DNP on the cell surface properties of marine bacteria and its implication for adhesion to surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    Jain, A.; Nishad, K.K.; Bhosle, N.B.

    The effect of 2, 4-dinitrophenol (DNP) on extracelluar polysaccharides (EPS), cell surface charge, and hydrophobicity of six marine bacterial cultures was studied, and its influence on attachment of these bacteria to glass and polystyrene...

  13. 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.

  14. Polyether sulfone/hydroxyapatite mixed matrix membranes for protein purification

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junfen, E-mail: junfensun@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, North People Road 2999, Shanghai 201620 (China); Wu, Lishun [Department of Chemistry and Chemical Engineering, Heze University, Daxue Road 2269, Heze, Shandong Province 274015 (China)

    2014-07-01

    This work proposes a novel approach for protein purification from solution using mixed matrix membranes (MMMs) comprising of hydroxyapatite (HAP) inside polyether sulfone (PES) matrix. The influence of HAP particle loading on membrane morphology is studied. The MMMs are further characterized concerning permeability and adsorption capacity. The MMMs show purification of protein via both diffusion as well as adsorption, and show the potential of using MMMs for improvements in protein purification techniques. The bovine serum albumin (BSA) was used as a model protein. The properties and structures of MMMs prepared by immersion phase separation process were characterized by pure water flux, BSA adsorption and scanning electron microscopy (SEM).

  15. Disinfectant properties of acid mine drainage: its effects on enteric bacteria in a sewage-contaminated stream

    Energy Technology Data Exchange (ETDEWEB)

    Keating, S.T.; Celements, C.M.; Ostrowski, D.; Hanlon, T. [St. Francis College, Loretto, PA (United States). Dept. of Biology

    1996-09-01

    Studies conducted in a Cambria County, Pennsylvania, acid mine drainage stream suggest that mine drainage rapidly reduces in situ populations of fecal bacteria associated with inputs of untreated sewage. The density of lactose-fermenting bacteria, mostly coliform species from sewage, declined 1000-fold over a distance of less than 100 m following the input of high acid (pH 3.5 to 4.0), high ferrous iron (45 mg/l) acid mine drainage. Enterobacteriaceae were isolated from the stream, identified, and tested for tolerance to acid mine drainage by exposing cells to drainage for 10 minutes at 0 or 37{degree}C. Populations of all tested isolates were reduced by this treatment, but some isolates were significantly less affected than others. Thus, while mine drainage may act as a disinfectant, it may not reduce all populations of disease-causing intestinal bacteria at an equal, rapid rate.

  16. Biosynthesis, purification and receptor binding properties of high specific radioactivity 1α,24(R), 25-trihydroxy-[26,27-methyl-3H]-vitamin D3

    International Nuclear Information System (INIS)

    Chandler, J.S.; Pike, J.W.; Haussler, M.R.

    1982-01-01

    A procedure for the biosynthesis and purification of 1α,24(R),25-trihydroxy[26,27-methyl- 3 H]-vitamin D 3 (1,24,25-(OH) 3 [ 3 H]D 3 ) is reported. A kidney homogenate from chicks receiving a high calcium diet (3%) and oral supplements of 1α,25-dihydroxyvitamin D 3 (1,25-(OH) 2 D 3 ) was used for C-24-hydroxylation of 1α,25-dihydroxy[26,27-methyl- 3 H]-vitamin D 3 (1,25-(OH) 2 [ 3 H]D 3 ), in vitro. Extraction and purification of the homogenate lipid fraction by Sephadex LH-20 and high performance liquid chromatography yielded radiochemically pure 1,24,25-(OH) 3 [ 3 H]D 3 with a specific radioactivity equivalent to the initial substrate (166 Ci/mmol). The authenticity of the generated metabolite was assessed by co-migration with synthetic 1,24,25-(OH) 3 D 3 on high performance liquid chromatography and by equimolar competition with authentic radioinert 1,24,25-(OH) 3 D 3 for binding to a purified receptor protein from rat kidney. Binding studies indicate the trihydroxylated metabolite competes 40-50% as effectively as 1,25-(OH) 2 D 3 for hormone binding sites. Further analysis of 1,24,25-(OH) 3 D 3 -receptor interaction reveals a high-affinity, saturable binding with an apparent Ksub(d) of 2.2 x 10 -9 M. These studies demonstrate that although slightly less active than 1,25-(OH) 2 D 3 , 1,24,25-(OH) 3 D 3 is capable of hormone-like interactions, in vitro. The availability of this high specific radioactivity sterol should allow for clarification of its potential physiologic significance. (author)

  17. 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

  18. Effectiveness of liquid radioactive waste purification by inorganic granulated sorbents

    International Nuclear Information System (INIS)

    Komarevskij, V.M.; Stepanets, O.V.; Sharygin, L.M.; Matveev, S.A.

    1995-01-01

    Study results on purification of simulative and real liquid radioactive wastes from fission products radionuclides and by inorganic corrosion-nature sorbents 'Thermoxide' are presented. Properties by sorption of cesium, strontium and cobalt are studied; results of experiments on purification of weakly-salted water solutions (waste waters, ships drainage tanks, showers and laundries) of the Beloyarsk NPP are presented. Sorbents source characteristics are determined. 4 refs., 2 figs., 3 tabs

  19. The growth, properties and interactions of yeasts and bacteria associated with the maturation of Camembert and blue-veined cheeses.

    Science.gov (United States)

    Addis, E; Fleet, G H; Cox, J M; Kolak, D; Leung, T

    2001-09-19

    The growth of yeasts and bacteria were monitored during the maturation of Camembert and blue-veined cheese produced in Australia. Yeasts were prominent throughout maturation, growing to 10(5)-10(9)/g, depending on the manufacturer. Debaryomyces hansenii predominated, but there were lesser, inconsistent contributions from Yarrowia lipolytica. Of the non-lactic acid bacteria, Acinetobacter species were significant during the maturation of Camembert but not blue-veined cheeses, and grew to 10(6)-10(8) cfu/g. Staphylococcus and Micrococcus species were consistently isolated from the cheeses with Staphylococcus xylosus growing to 10(5)-10(9) cfu/g, depending on the product. Lactic acid bacteria (10(7)-10(9) cfu/g) were present throughout maturation but were not identified. Interactions between the various yeasts and bacterial isolates were examined. Several strains of D. hansenii exhibited killer activity but not against Y. lipolytica. None of the yeasts were antagonistic towards the bacteria but some strains of D. hansenii enhanced the growth of Y. lipolytica and S. xylosus. The yeast and bacterial isolates exhibited various degrees of extracellular proteolytic and lipolytic activities.

  20. 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

    We investigated the diversity, distribution, and phenotypes of uncultivated Chloroflexaceae-related bacteria in photosynthetic microbial mats of an alkaline hot spring (Mushroom Spring, Yellowstone National Park). By applying a directed PCR approach, molecular cloning, and sequence analysis of 16S...

  1. 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

  2. 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)

  3. Electron beam silicon purification

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Anatoly [SIA ' ' KEPP EU' ' , Riga (Latvia); Kravtsov, Alexey [' ' KEPP-service' ' Ltd., Moscow (Russian Federation)

    2014-11-15

    Purification of heavily doped electronic grade silicon by evaporation of N-type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150-300 kg) and yield solar grade silicon. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. 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.

  5. Anti-nociceptive properties in rodents and the possibility of using polyphenol-rich fractions from sida urens L. (Malvaceae) against of dental caries bacteria.

    Science.gov (United States)

    Konaté, Kiessoun; Zerbo, Patrice; Ouédraogo, Maurice; Dibala, Crépin I; Adama, Hilou; Sytar, Oksana; Brestic, Marian; Barro, Nicolas

    2013-06-21

    Sida urens L. (Malvaceae) is in flora of Asian medicinal herbs and used traditionally in West of Burkina Faso for the treatment of infectious diseases and particularly used against, dental caries bacteria, fever, pain and possesses analgesic properties. This study was conducted to reveal the antibacterial effect against dental caries bacteria on the one hand, and evaluate their analgesic capacity in experimental model with Swiss mice and on the other hand, with an aim to provide a scientific basis for the traditional use of this plant for the management of dental caries bacteria. The antibacterial assays in this study were performed by using inhibition zone diameters, MIC (Minimum inhibitory concentration) and MBC (Minimal bactericidal concentration) methods. On the whole the dental caries bacteria (Gram-positive and Gram-negative bacterial strains) were used. Negative control was prepared using discs impregnated with 10% DMSO in water and commercially available Gentamicin from Alkom Laboratories LTD was used as positive reference standards for all bacterial strains. In acute toxicity test, mice received doses of extract (acetone/water extract) from Sida urens L. by intraperitoneal route and LD50 was determined in Swiss mice. As for analgesic effects, acetic acid writhing method was used in mice. The acetic acid-induced writhing method was used in mice with aim to study analgesic effects. The results showed that the highest antibacterial activities were founded with the polyphenol-rich fractions against all bacterial strains compared to the standard antibiotic. About preliminary study in acute toxicity test, LD50 value obtained was more than 5000 mg/kg b.w. Polyphenol-rich fractions produced significant analgesic effects in acetic acid-induced writhing method and in a dose-dependent inhibition was observed. These results validate the ethno-botanical use of Sida urens L. (Malvaceae) and demonstrate the potential of this herbaceous as a potential antibacterial agent

  6. Superoxide dismutase (SOD) in boar spermatozoa: purification, biochemical properties and changes in activity during semen storage (16°C) in different extenders.

    Science.gov (United States)

    Orzołek, Aleksandra; Wysocki, Paweł; Strzeżek, Jerzy; Kordan, Władysław

    2013-03-01

    The antioxidant system in semen is composed of enzymes, low-molecular weight antioxidants and seminal plasma proteins. Loss of enzymatic activity of superoxide dismutase (SOD) during semen preservation may cause insufficient antioxidant defense of boar spermatozoa. The aim of this study was to isolate and characterize SOD molecular forms from spermatozoa and to describe changes in SOD activity in boar sperm during preservation at 16°C. Sperm extracts were prepared from fresh or diluted semen and used for SOD purification or activity measurement. Ion-exchange chromatography and gel filtration was used to purify SOD molecular forms. BTS, Dilu Cell, M III and Vitasem were used as diluents for 5-day storage of semen at +16°C. The molecular form of SOD released from spermatozoa after cold shock and homogenization had a molecular weight of approximately 67kDa. The activity of the SOD form was the highest at pH 10 within the temperature range between 20 and 45°C. The enzymatic activity of form released after cold shock was inhibited by H2O2 and diethyldithiocarbamate (DDC; by 65 and 40%, respectively). The SOD form released by homogenization was inhibited by H2O2 and DDC (40%). The molecular form released after urea treatment was a 30kDa protein with maximum activity at 20°C and pH 10. Enzymatic activity of this form was inhibited by H2O2 by 35%, DDC by 80% and 2-mercaptoethanol by 15%. The antigenic determinants of SOD isolated from boar seminal plasma and spermatozoa were similar to each other. Susceptibility of spermatozoa to cold shock increased during storage, but the differences between extenders were statistically non-significant. Copyright © 2013 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  7. 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

  8. Purification and characterization of VDE, a site-specific endonuclease from the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Gimble, F S; Thorner, J

    1993-10-15

    The 119-kDa primary translation product of the VMA1 gene of Saccharomyces cerevisiae undergoes a self-catalyzed rearrangement ("protein splicing") that excises an internal 50-kDa segment of the polypeptide and joins the amino-terminal and carboxyl-terminal segments to generate the 69-kDa subunit of the vacuolar membrane-associated H(+)-ATPase. We have shown previously that the internal segment is a site-specific endonuclease (Gimble, F. S., and Thorner, J. (1992) Nature 357, 301-306). Here we describe methods for the high level expression and purification to near homogeneity of both the authentic VMA1-derived endonuclease (or VDE) from yeast (yield 18%) and a recombinant form of VDE made in bacteria (yield 29%). Detailed characterization of these preparations demonstrated that the yeast-derived and bacterially produced enzymes were indistinguishable, as judged by: (a) behavior during purification; (b) apparent native molecular mass (50 kDa); (c) immunological reactivity; and (d) catalytic properties (specific activity; cleavage site recognition; and optima for pH, temperature, divalent cation and ionic strength). The minimal site required for VDE cleavage was delimited to a 30-base pair sequence within its specific substrate (the VMA1 delta vde allele).

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. In-Situ Determination of the Mechanical Properties of Gliding or Non-Motile Bacteria by Atomic Force Microscopy under Physiological Conditions without Immobilization

    Science.gov (United States)

    Dhahri, Samia; Ramonda, Michel; Marlière, Christian

    2013-01-01

    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. PMID:23593493

  16. The purification by ion exchange resins of the heavy water la the reactors EL1 and EL2. B - study of the general properties of the resins used; Purification par resines echangeuses d'ions de l'eau lourde de reacteurs EL1 et EL2. B - etude des proprietes generales des resines utilisees

    Energy Technology Data Exchange (ETDEWEB)

    Fourre,; Platzer, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    Within the programme of the pile heavy water purification project, organized by the stable Isotopes Section, we have carried out a certain number of tests on ion exchange resins. The problem posed by the stable Isotopes Section was to determine the conditions of utilisation of ion exchange resins, knowing that they would be employed in a system branching off the heavy water circuit in the piles. These investigations were carried out in close collaboration with the stable Isotopes Section, and were guided chiefly by the extremely short delay permitted between the laboratory study and its application to the piles. The tests are divided into two groups: 1- General properties of the resins. 2- Utilisation of the resins, particularly in an apparatus similar to those mounted on the piles but of smaller dimensions. (author) [French] Dans le cadre du projet d'epuration de l'eau lourde des piles, traite par la Section des Isotopes stables, nous avons fait un certain nombre d'essais sur les resines echangeuses d'ions. Le probleme pose par la Section des Isotopes stables etait de determiner les conditions d'utilisation des resines echangeuses d'ions sachant qu'elles devraient etre employees dans un appareil place en derivation sur le circuit d'eau lourde des piles. L'ensemble de l'etude a ete mene en collaboration etroite avec la Section des Isotopes stables et a ete guide principalement par le delai extremement court dans lequel l'etude de laboratoire devait etre appliquee aux piles. Les essais se divisent en deux groupes: 1- Proprietes generales des resines. 2- Utilisation des resines, en particulier dans un appareil analogue a ceux montes sur les piles, mais de dimensions reduites. (auteur)

  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. 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.

  19. 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.

  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......, 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...

  1. 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...

  2. 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)

  3. 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.

  4. 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...

  5. 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

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Poliana de Paula; Azevedo, Heliana de; Roque, Claudio Vitor; Pomarico Neto, Walter, E-mail: hgomes@cnen.gov.br, E-mail: pbrito@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: abrusqui@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Mourao, Gerson Barreto; Orlando, Eduardo Adilson; Miyagusku, Luciana, E-mail: marciamh@ital.sp.gov.br, E-mail: eduardo.orlando@ital.sp.gov.br [Instituto de Tecnologia dos Alimentos (ITAL), Campinas, SP (Brazil)

    2013-07-01

    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)

  6. 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)

  7. 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

  8. 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.

  9. 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.

  10. Future of antibody purification.

    Science.gov (United States)

    Low, Duncan; O'Leary, Rhona; Pujar, Narahari S

    2007-03-15

    Antibody purification seems to be safely ensconced in a platform, now well-established by way of multiple commercialized antibody processes. However, natural evolution compels us to peer into the future. This is driven not only by a large, projected increase in the number of antibody therapies, but also by dramatic improvements in upstream productivity, and process economics. Although disruptive technologies have yet escaped downstream processes, evolution of the so-called platform is already evident in antibody processes in late-stage development. Here we perform a wide survey of technologies that are competing to be part of that platform, and provide our [inherently dangerous] assessment of those that have the most promise.

  11. 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...

  12. Expression, purification, crystallization and preliminary X-ray analysis of eCGP123, an extremely stable monomeric green fluorescent protein with reversible photoswitching properties

    International Nuclear Information System (INIS)

    Don Paul, Craig; Traore, Daouda A. K.; Byres, Emma; Rossjohn, Jamie; Devenish, Rodney J.; Kiss, Csaba; Bradbury, Andrew; Wilce, Matthew C. J.; Prescott, Mark

    2011-01-01

    eCGP123, an extremely stable GFP with photoswitching properties, has been expressed, purified and crystallized. A diffraction data set has been collected at 2.10 Å resolution. Enhanced consensus green protein variant 123 (eCGP123) is an extremely thermostable green fluorescent protein (GFP) that exhibits useful negative reversible photoswitching properties. eCGP123 was derived by the application of both a consensus engineering approach and a recursive evolutionary process. Diffraction-quality crystals of recombinant eCGP123 were obtained by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. The eCGP123 crystal diffracted X-rays to 2.10 Å resolution. The data were indexed in space group P1, with unit-cell parameters a = 74.63, b = 75.38, c = 84.51 Å, α = 90.96, β = 89.92, γ = 104.03°. The Matthews coefficient (V M = 2.26 Å 3 Da −1 ) and a solvent content of 46% indicated that the asymmetric unit contained eight eCGP123 molecules

  13. 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.

  14. Electro-responsive supramolecular graphene oxide hydrogels for active bacteria adsorption and removal

    Science.gov (United States)

    Xue, Bin; Cao, Yi; Wang, Wei

    Bacteria are major contaminations in drinking water and healthcare products. Bacteria contamination may cause severe health problems, including food poisoning and diseases. Currently water sterilization and purification methods to remove contaminated bacteria are mainly based on the size-exclusion mechanism. In order to completely remove all bacteria in water, the pore sizes of the membranes or cartilages should be comparable to the size of bacteria, which inevitable leads to high cross-membrane water pressure and slow purification speed. Moreover, the membranes can easily get clogged. Therefore it is highly demanded to develop efficient methods and novel materials for water purification. Recently, Cui and coworker have introduced a bacteria inactivation method with high efficiency and fast purification speed based on a kind of complex materials made of silver nanofibers, carbon nanotubes and cotton, operating in an electric field. With the help of electric field, the bacteria can be efficiently kill when passing through the membrance even the pore sizes are larger than bacteria. Inspired by their work, here we report a proof-of-principle demonstration of bacteria removal using electro-reponsive hydrogels. This work is funded by Six talent peaks project in Jiangsu Province, the National Natural Science Foundation of China (Nos. 11304156, 11334004, 31170813, 81421091 and 91127026), the 973 Program of China (No. 2012CB921801 and 2013CB834100), the Priority Ac.

  15. Comparison of five procedures for the purification of insoluble elastin.

    NARCIS (Netherlands)

    Daamen, W.F.; Hafmans, T.G.M.; Veerkamp, J.H.; Kuppevelt, A.H.M.S.M. van

    2001-01-01

    Elastin is an insoluble, highly cross-linked protein, providing elasticity to organs like lung. aorta, and ligaments. Despite its remarkable mechanical properties. elastin has found little use as a biomaterial. Purification of intact elastin from elastic fibres presents a major challenge, among

  16. Recovery and purification of ethylene

    Science.gov (United States)

    Reyneke, Rian [Katy, TX; Foral, Michael J [Aurora, IL; Lee, Guang-Chung [Houston, TX; Eng, Wayne W. Y. [League City, TX; Sinclair, Iain [Warrington, GB; Lodgson, Jeffery S [Naperville, IL

    2008-10-21

    A process for the recovery and purification of ethylene and optionally propylene from a stream containing lighter and heavier components that employs an ethylene distributor column and a partially thermally coupled distributed distillation system.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. Field-emission property of self-purification SiC/SiOx coaxial nanowires synthesized via direct microwave irradiation using iron-containing catalyst

    Science.gov (United States)

    Zhou, Qing; Yu, Yongzhi; Huang, Shan; Meng, Jiang; Wang, Jigang

    2017-07-01

    SiC/SiOx coaxial nanowires were rapidly synthesized via direct microwave irradiation in low vacuum atmosphere. During the preparation process, only graphite, silicon, silicon dioxide powders were used as raw materials and iron-containing substance was employed as catalyst. Comprehensive characterizations were employed to investigate the microstructure of the products. The results showed that a great quantity of coaxial nanowires with uniform sizes and high aspect ratio had been successfully achieved. The coaxial nanowires consist of a silicon oxide (SiOx) shell and a β-phase silicon carbide (β-SiC) core that exhibited in special tube brush like. In additional, nearly all the products were achieved in the statement of pure SiC/SiOx coaxial nanowires without the existence of metallic catalyst, indicating that the self-removal of iron (Fe) catalyst should be occurred during the synthesis process. Photoluminescence (PL) spectral analysis result indicated that such novel SiC/SiOx coaxial nanowires exhibited significant blue-shift. Besides, the measurement results of field-emission (FE) demonstrated that the SiC/SiOx coaxial nanowires had ultralow turn-on field and threshold field with values of 0.2 and 2.1 V/μm, respectively. The hetero-junction structure formed between SiOx shell and SiC core, lots of emission sites, as well as clear tips of the nanowires were applied to explain the excellent FE properties.[Figure not available: see fulltext.

  2. Purification and characterization of a protease-resistant phytase of Aspergillus oryzae SBS50 whose properties make it exceptionally useful as a feed supplement.

    Science.gov (United States)

    Sapna; Singh, Bijender

    2017-10-01

    An extracellular phytase of Aspergillus oryzae SBS50 was purified to homogeneity using ammonium sulphate precipitation, ion-exchange and gel filtration chromatography. Purified phytase has a monomeric molecular mass of ∼80kDa exhibiting its optimal activity at pH 5.0 and 50°C with a T 1/2 of 300min at 50°C. Phytase of A. oryzae displayed broad substrate specificity with V max and K m values of 58.82μmol/ml/min and 1.14mM, respectively, for calcium phytate. Purity and homogeneity of the phytase was confirmed by high performance liquid chromatography and MALDI-TOF analysis revealed the identification of a peptide showing homology with acid phosphatase of Aspergillus oryzae RIB40. Among the inhibitors, 2,3-butanedione and sodium molybdate significantly inhibited the enzyme activity. Phytase of A. oryzae showed protease-resistance and was more stable during storage at 4°C and -20°C as compared to room temperature. Among all the feed samples, mustard oil cake was dephytinized more efficiently than other feed samples. These unique properties suggested that the phytase has the potential to be useful as an animal feed supplement. Copyright © 2017 Elsevier B.V. All rights reserved.

  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. A new cold-adapted β-D-galactosidase from the Antarctic Arthrobacter sp. 32c – gene cloning, overexpression, purification and properties

    Directory of Open Access Journals (Sweden)

    Kur Józef

    2009-07-01

    Full Text Available Abstract Background The development of a new cold-active β-D-galactosidases and microorganisms that efficiently ferment lactose is of high biotechnological interest, particularly for lactose removal in milk and dairy products at low temperatures and for cheese whey bioremediation processes with simultaneous bio-ethanol production. Results In this article, we present a new β-D-galactosidase as a candidate to be applied in the above mentioned biotechnological processes. The gene encoding this β-D-galactosidase has been isolated from the genomic DNA library of Antarctic bacterium Arthrobacter sp. 32c, sequenced, cloned, expressed in Escherichia coli and Pichia pastoris, purified and characterized. 27 mg of β-D-galactosidase was purified from 1 L of culture with the use of an intracellular E. coli expression system. The protein was also produced extracellularly by P. pastoris in high amounts giving approximately 137 mg and 97 mg of purified enzyme from 1 L of P. pastoris culture for the AOX1 and a constitutive system, respectively. The enzyme was purified to electrophoretic homogeneity by using either one step- or a fast two step- procedure including protein precipitation and affinity chromatography. The enzyme was found to be active as a homotrimeric protein consisting of 695 amino acid residues in each monomer. Although, the maximum activity of the enzyme was determined at pH 6.5 and 50°C, 60% of the maximum activity of the enzyme was determined at 25°C and 15% of the maximum activity was detected at 0°C. Conclusion The properties of Arthrobacter sp. 32cβ-D-galactosidase suggest that this enzyme could be useful for low-cost, industrial conversion of lactose into galactose and glucose in milk products and could be an interesting alternative for the production of ethanol from lactose-based feedstock.

  5. Liquid metal purification device

    International Nuclear Information System (INIS)

    Sakai, Takao; Shimoyashiki, Shigehiro.

    1992-01-01

    The device of the present invention concerns a liquid metal purification device for removing and purifying impuries in liquid metal sodium used as coolants of an FBR type reactor. A vessel having a group of pipes made of hydrogen permeable metal at the inside thereof is disposed to the inlet pipeline of a cold trap. The group of hydrogen permeable metal pipes is connected to an exhaust pipe and a vacuum pump, so that the inside of the pipes is exhausted. Liquid metal sodium branched from the main pipeline of a coolant system passes through the outer side of the group of the hydrogen permeable metal pipes. In this cae, hydrogen contained as impurities in the liquid metal sodium diffuses and permeates the hydrogen permeation metal pipes and enters into the pipe group and is discharged out of the system by the vacuum pump. This can mitigate the hydrogen removing burden of the cold trap, to extend the device life time. (I.N.)

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

    Directory of Open Access Journals (Sweden)

    Jo-Ana eHerweg

    2015-06-01

    Full Text Available 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.

  7. 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)

  8. Simple purification method for a recombinantly expressed native His-tag-free aminopeptidase A from Lactobacillus delbrueckii.

    Science.gov (United States)

    Stressler, Timo; Tanzer, Coralie; Ewert, Jacob; Claaßen, Wolfgang; Fischer, Lutz

    2017-03-01

    The aminopeptidase A (PepA; EC 3.4.11.7) is an intracellular exopeptidase present in lactic acid bacteria. The PepA cleaves glutamyl/aspartyl residues from the N-terminal end of peptides and can, therefore, be applied for the production of protein hydrolysates with an increased amount of these amino acids, which results in a savory taste (umami). The first PepA from a lactobacilli strain was recombinantly expressed in Escherichia coli in a recently published study and harbored a C-terminal His 6 -tag for easier purification. Due to the fact that a His-tag might influence the properties of an enzyme, a simple purification method for the non-His-tagged PepA was required. Surprisingly, the PepA precipitated at a very low ammonium sulfate concentration of 5%. Unusual for a precipitating step, the purity of PepA was over 95% and the obtained activity yield was 110%. The high purity allows biochemical characterization and kinetic investigation. As a result, the optimum pH (6.0-6.5) and temperature (60-65 °C) were comparable to the His 6 -tag harboring PepA; the K M value was at 0.79 mM slightly lower compared to 1.21 mM, respectively. Since PepA is a homo dodecamer, it has a high molecular mass of approximately 480 kDa. Therefore, a subsequent preparative size-exclusion chromatography (SEC) step seemed promising. The PepA after SEC was purified to homogeneity. In summary, the simple two-step purification method presented can be applied to purify high amounts of PepA that will allow the performance of experiments in the future to crystalize PepA for the first time. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. 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.

  10. 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

  11. Antimicrobial Peptide Production and Purification.

    Science.gov (United States)

    Suda, Srinivas; Field, Des; Barron, Niall

    2017-01-01

    Antimicrobial peptides (AMPs) are natural defense compounds which are synthesized as ribosomal gene-encoded pre-peptides and produced by all living organisms. AMPs are small peptides, usually cationic and typically have hydrophobic residues which interact with cell membranes and have either a narrow or broad spectrum of biological activity. AMPs are isolated from the natural host or heterologously expressed in other hosts such as Escherichia coli. The proto-typical lantibiotic Nisin is a widely used AMP that is produced by the food-grade organism Lactococcus lactis. Although AMP production and purification procedures require optimization for individual AMPs, the Nisin production and purification protocol outlined in this chapter can be easily applied with minor modifications for the production and purification of other lantibiotics or AMPs. While Nisin is produced and secreted into the supernatant, steps to recover Nisin from both cell-free supernatant and cell pellet are outlined in detail.

  12. 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.

  13. The various sodium purification techniques

    International Nuclear Information System (INIS)

    Courouau, J.L.; Masse, F.; Rodriguez, G.; Latge, C.; Redon, B.

    1997-01-01

    In the framework of sodium waste treatment, the sodium purification phase plays an essential role in the chain of operations leading to the transformation of the active sodium, considered as waste, into a stable sodium salt. The objectives of the purification operations are: To keep a low impurity level, particularly a low concentration in oxygen and hydrogen, in order to allow its transfer to a processing plant, and in order to avoid risks of plugging and/or corrosion in sodium facilities; To reduce the sodium activity in order to limit the dose rate close to the facilities, and in order to reduce the activity of the liquid and gaseous effluents. After a recall of the different kind of impurities that can be present in sodium, and of the different purification methods that could be associated with, the following points are highlighted: (i) Oxygen and hydrogen purification needs, and presentation of some selection criteria for a purification unit adapted to a sodium processing plant, as well as 2 cold trap concepts that are in accordance with these criteria: PSICHOS and PIRAMIDE. (ii) Tritium reduction in a bulk of liquid sodium by swamping, isotopic exchange, or permeation throughout a membrane. (iii) Caesium trapping on carbonaceous matrix. The main matrices used at present are R.V.C. (Reticulated Vitreous Carbon) and Actitex/Pica products. Tests in the laboratory and on an experimental device have demonstrated the performances of these materials, which are able to reduce sodium activity in Cs 134 and Cs 137 to very low values. The sodium purification processes as regards to the hydrogen, oxygen and caesium, that are aimed at facilitating the subsequent treatment of sodium, are therefore mastered operations. Regarding the operations associated with the reduction of the tritium activity, the methods are in the process of being qualified, or to be qualified. (author)

  14. 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 ...

  15. 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.

  16. Staphylococcus cohnii hemolysins - isolation, purification and properties.

    Science.gov (United States)

    Rózalska, M; Szewczyk, E M

    2008-01-01

    A total 355 of Staphylococcus cohnii isolates from hospital environment, patients (newborns), medical staff and from non-hospital environment were tested for hemolytic activity. Ninety-one % of S. cohnii ssp. cohnii and 74.5 % S. cohnii ssp. urealyticus strains exhibited hemolysis synergistic to S. aureus ATCC 25923 strain. Crude preparations of hemolysins of both bacterial subspecies presented delta-hemolysin, but not alpha- and beta-toxin activity. Highly pure hemolysins were obtained by semipreparative SDS-PAGE or by organic solvent extraction from the freeze-dried crude preparations. Native-PAGE and 2D-PAGE showed their high heterogeneity. Molar masses of single hemolysin units estimated by the Tris-Tricine-SDS-PAGE were calculated as 3.47 kDa for S. cohnii ssp. cohnii and 3.53 kDa for S. cohnii ssp. urealyticus.

  17. 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 ...

  18. Materials for Molybdenum 99 purification

    International Nuclear Information System (INIS)

    Wilkinson, M. Victoria; Mondino, Angel V.; Manzini, Alberto C.

    2003-01-01

    The National Atomic Energy Commission (CNEA) produces fission Mo 99, an isotope of wide use in nuclear medicine. In order to simplify the current Mo 99 production process, to shorten its duration and reduce impurities in the final product, alternative methods for purification steps were looked for. In this work a variety of new materials for the purification columns were designed, all of them with carbon. These materials were studied and a material which contribute with the best results for molybdenum retention, was selected. The preparation procedure and the working conditions were determined. (author)

  19. Hydrogen purification by periodic adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Barg, Christian; Secchi, Argimiro R.; Trierweiler, Jorge O. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica]. E-mail: cbarg@enq.ufrgs.br; arge@enq.ufrgs.br; jorge@enq.ufrgs.br

    2000-07-01

    The periodic adsorption processes have been widely used for industrial applications, mainly because it spends less energy than the usual gas separation processes, like the cryogenic distillation. The largest commercial application of periodic adsorption processes is the pressure swing adsorption (PSA) applied to hydrogen purification. Although its wide use in the chemical and petrochemical industry, there are no reports in the open literature about complete modeling studies of a complex commercial unit, with multiple adsorbents and multiple beds and several feed components. This study has as objective the modeling, optimization and dynamical analysis of an industrial PSA unit for hydrogen purification. (author)

  20. 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.

  1. Handling technique of spore-forming bacteria in radiation sterilization. 1. Preparation of spores

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko

    1994-01-01

    This paper deals with a handling technique of spore-forming bacteria in radiation sterilization. An explanation is given under three sections: (1) life cycle of spore-forming bacteria, medium to form bacterial spores, and colony and purification methods of bacterial spores; (2) methods for measuring the number of bacterial spores and resistance against gamma radiation (D values); and (3) a test method for identifying spore-forming bacteria and a simple identification method. (N.K.)

  2. Rumen bacteria

    International Nuclear Information System (INIS)

    McSweeney, C.S.; Denman, S.E.; Mackie, R.I.

    2005-01-01

    The rumen is the most extensively studied gut community and is characterized by its high population density, wide diversity and complexity of interactions. This complex, mixed microbial culture is comprised of prokaryote organisms including methane-producing archaebacteria, eukaryote organisms, such as ciliate and flagellate protozoa, anaerobic phycomycete fungi and bacteriophage. Bacteria are predominant (up to 10 11 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (10 4 -10 6 /g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 10 2 -10 4 /g distributed over 5 genera). The occurrence of bacteriophage is well documented (10 7 -10 9 particles/g). This section focuses primarily on the widely used methods for the cultivation and the enumeration of rumen microbes, especially bacteria, which grow under anaerobic conditions. Methods that can be used to measure hydrolytic enzymes (cellulases, xylanases, amylases and proteinases) are also described, along with cell harvesting and fractionation procedures. Brief reference is also made to fungi and protozoa, but detailed explanations for culturing and enumerating these microbes is presented in Chapters 2.4 and 2.5

  3. Strep-Tagged Protein Purification.

    Science.gov (United States)

    Maertens, Barbara; Spriestersbach, Anne; Kubicek, Jan; Schäfer, Frank

    2015-01-01

    The Strep-tag system can be used to purify recombinant proteins from any expression system. Here, protocols for lysis and affinity purification of Strep-tagged proteins from E. coli, baculovirus-infected insect cells, and transfected mammalian cells are given. Depending on the amount of Strep-tagged protein in the lysate, a protocol for batch binding and subsequent washing and eluting by gravity flow can be used. Agarose-based matrices with the coupled Strep-Tactin ligand are the resins of choice, with a binding capacity of up to 9 mg ml(-1). For purification of lower amounts of Strep-tagged proteins, the use of Strep-Tactin magnetic beads is suitable. In addition, Strep-tagged protein purification can also be automated using prepacked columns for FPLC or other liquid-handling chromatography instrumentation, but automated purification is not discussed in this protocol. The protocols described here can be regarded as an update of the Strep-Tag Protein Handbook (Qiagen, 2009). © 2015 Elsevier Inc. All rights reserved.

  4. Purification Simulation With Vapor Permeation and Distillation-Adsorption In Bioethanol Plant

    OpenAIRE

    Misri Gozan; Mia Sari Setiawan; Kenny Lischer

    2017-01-01

    High purity of Bioethanol is required in biofuel mixing with gasoline (EXX). In bioethanol production line, the azeotropic property of ethanol-water becomes the barrier for purification process. This study examined two bioethanol separation processes by support of simulation tools, Superpro Designer 9.0 software. Ethanol purity and a low costeconomical process were the major considerations. Purification method of vapor permeation membrane technology was compared with distillation-adsorption m...

  5. Purification of antilisterial bacteriocins.

    Science.gov (United States)

    Berjeaud, Jean-Marc; Cenatiempo, Yves

    2004-01-01

    In recent years, numerous contamination outbreaks, involving various pathogens (i.e., Listeria and Salmonella), have increased concern over food preservation. Research efforts have focused on the discovery of new molecules targeting such foodborne pathogens and therefore able to inhibit and or kill them. Lactic acid bacteria (LAB) extensively used in fermented foods for thousands of years not only improve their flavor and texture but also inhibit pathogenic and spoilage microorganisms. LAB inhibitory activity is primarily owing to pH decrease and competition for substrates. Antagonistic activity of LAB also depends on secreted antimicrobial compounds with a poor selectivity, such as metabolic compounds (i.e., hydrogen peroxide, acetoin, and others) or more specific ones like bacteriocins. The latter are proteinaceous compounds, ribosomally synthesized and subsequently secreted by Gram-positive as well as Gram-negative bacteria. Their antimicrobial activity is generally restricted to strains phylogenetically related to the producers.A classification of bacteriocins produced by LAB was first proposed by Klaenhammer in 1993 and was modified by Nes et al. in 1996; class I and class II bacteriocins are the most abundant and thoroughly studied. Bacteriocins from both classes exhibit antilisterial activity. Class I bacteriocins, namely, lantibiotics, have been widely studied, and among them, nisin is used in many countries as a preservative in food products. These bacteriocins are characterized by the presence, in their primary structure, of post-translationally modified amino acid residues (i.e., lanthionine and methylanthionine) that are formed. Class II bacteriocins, containing three subclasses, consist of small peptides that do not bear any modified amino acid residue. The most studied subclass corresponds to class IIa, also termed anti-Listeria bacteriocins. These peptides share strong structural homologies in their N-terminal domain, with the presence of one

  6. 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.

  7. 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.

  8. 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.

  9. Extraction and purification of plutonium by a tertiary amine; Extraction et purification du plutonium par une amine tertiaire

    Energy Technology Data Exchange (ETDEWEB)

    Trentinian, M de; Chesne, A [Commissariat a l' Energie Atomique, Fontenay aux Roses, Section de Chimie des Actimides (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    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) [French] La trilaurylamine diluee par un solvant paraffinique (dodecane) a ete etudiee dans le cadre des recherches concernant la separation et la purification du plutonium. Une etude des caracteres physiques (solubilite des nitrates dans l'amine en fonction de la temperature) s'ajoute a celle de la tenue aux radiations de ce corps. Les caracteristiques d'extraction de solutions nitriques de plutonium, uranium, et certains produits de fission, sont donnes en fonction des facteurs suivants: concentration des differents ions en solution, etats de valence. On presente une methode de purification du plutonium basee sur ces resultats. (auteur)

  10. Sodium purification in Rapsodie; La purification du sodium a Rapsodie

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, B [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Cadarache (France). Centre d' Etudes Nucleaires

    1968-07-01

    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) [French] Ce rapport fait partie d'une serie de publications presentant l'essentiel des resultats des essais effectues a l'occasion du demarrage du premier reacteur francais a neutrons rapides: RAPSODIE. Cet article expose les techniques de la purification du sodium utilise dans les circuits de refroidissement du reacteur tant au point de vue de leur realisation technologique, que des resultats obtenus pendant la premiere annee de fonctionnement. (auteur)

  11. Unifying principles in homodimeric type I photosynthetic reaction centers: properties of PscB and the FA, FB and FX iron-sulfur clusters in green sulfur bacteria.

    Science.gov (United States)

    Jagannathan, Bharat; Golbeck, John H

    2008-12-01

    The photosynthetic reaction center from the green sulfur bacterium Chlorobium tepidum (CbRC) was solubilized from membranes using Triton X-100 and isolated by sucrose density ultra-centrifugation. The CbRC complexes were subsequently treated with 0.5 M NaCl and ultrafiltered over a 100 kDa cutoff membrane. The resulting CbRC cores did not exhibit the low-temperature EPR resonances from FA- and FB- and were unable to reduce NADP+. SDS-PAGE and mass spectrometric analysis showed that the PscB subunit, which harbors the FA and FB clusters, had become dissociated, and was now present in the filtrate. Attempts to rebind PscB onto CbRC cores were unsuccessful. Mössbauer spectroscopy showed that recombinant PscB contains a heterogeneous mixture of [4Fe-4S]2+,1+ and other types of Fe/S clusters tentatively identified as [2Fe-2S]2+,1+ clusters and rubredoxin-like Fe3+,2+ centers, and that the [4Fe-4S]2+,1+ clusters which were present were degraded at high ionic strength. Quantitative analysis confirmed that the amount of iron and sulfide in the recombinant protein was sub-stoichiometric. A heme-staining assay indicated that cytochrome c551 remained firmly attached to the CbRC cores. Low-temperature EPR spectroscopy of photoaccumulated CbRC complexes and CbRC cores showed resonances between g=5.4 and 4.4 assigned to a S=3/2 ground spin state [4Fe-4S]1+ cluster and at g=1.77 assigned to a S=1/2 ground spin state [4Fe-4S]1+ cluster, both from FX-. These results unify the properties of the acceptor side of the Type I homodimeric reaction centers found in green sulfur bacteria and heliobacteria: in both, the FA and FB iron-sulfur clusters are present on a salt-dissociable subunit, and FX is present as an interpolypeptide [4Fe-4S]2+,1+ cluster with a significant population in a S=3/2 ground spin state.

  12. 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.

  13. The bubble method of water purification

    Science.gov (United States)

    Smirnov, B. M.; Babaeva, N. Yu.; Naidis, G. V.; Panov, V. A.; Saveliev, A. S.; Son, E. E.; Tereshonok, D. V.

    2018-02-01

    The processes of water purification from admixture molecules are analyzed. The purification rate is limited due to a low diffusion coefficient of the admixture molecules in water. At non-small concentrations of the admixture molecules, the water purication can proceed through association of molecules in condensed nanoparticles which fall on the bottom of the water volume. The rate of association may be increased in an external electric field, but in reality this cannot change significantly the rate of the purification process. The bubble method of water purification is considered, where air bubbles formed at the bottom of the water volume, transfer admixture molecules to the interface. This method allows one to clean small water volumes fast. This mechanism of water purification is realized experimentally and exhibits the promises of the bubble purification method.

  14. 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.

  15. Plasmid pVAX1-NH36 purification by membrane and bead perfusion chromatography.

    Science.gov (United States)

    Franco-Medrano, Diana Ivonne; Guerrero-Germán, Patricia; Montesinos-Cisneros, Rosa María; Ortega-López, Jaime; Tejeda-Mansir, Armando

    2017-03-01

    The demand for plasmid DNA (pDNA) has increased in response to the rapid advances in vaccines applications to prevent and treat infectious diseases caused by virus, bacteria or parasites, such as Leishmania species. The immunization protocols require large amounts of supercoiled plasmid DNA (sc-pDNA) challenging the development of efficient and profitable processes for capturing and purified pDNA molecules from large volumes of lysates. A typical bioprocess involves four steps: fermentation, primary recovery, intermediate recovery and final purification. Ion-exchange chromatography is one of the key operations in the purification schemes of pDNA owing the chemical structure of these macromolecules. The goal of this research was to compare the performance of the final purification step of pDNA using ion-exchange chromatography on columns packed with Mustang Q membranes or perfusive beads POROS 50 HQ. The experimental results showed that both matrixes could separate the plasmid pVAX1-NH36 (3936 bp) from impurities in clarified Escherichia coli lysates with an adequate resolution. In addition, a 24- and 21-fold global purification factor was obtained. An 88 and 63% plasmid recuperation was achieved with ion-exchange membranes and perfusion beads, respectively. A better understanding of perfusion-based matrices for the purification of pDNA was developed in this research.

  16. Purification of a lectin from Eugenia uniflora L. seeds and its potential antibacterial activity.

    Science.gov (United States)

    Oliveira, M D L; Andrade, C A S; Santos-Magalhães, N S; Coelho, L C B B; Teixeira, J A; Carneiro-da-Cunha, M G; Correia, M T S

    2008-03-01

    The aim of this work was to analyse the antimicrobial properties of a purified lectin from Eugenia uniflora L. seeds. The E. uniflora lectin (EuniSL) was isolated from the seed extract and purified by ion-exchange chromatography in DEAE-Sephadex with a purification factor of 11.68. The purified lectin showed a single band on denaturing electrophoresis, with a molecular mass of 67 kDa. EuniSL agglutinated rabbit and human erythrocytes with a higher specificity for rabbit erythrocytes. The haemagglutination was not inhibited by the tested carbohydrates but glycoproteins exerted a strong inhibitory action. The lectin proved to be thermo resistant with the highest stability at pH 6.5 and divalent ions did not affect its activity. EuniSL demonstrated a remarkable nonselective antibacterial activity. EuniSL strongly inhibited the growth of Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella sp. with a minimum inhibitory concentration (MIC) of 1.5 microg ml(-1), and moderately inhibited the growth of Bacillus subtilis, Streptococcus sp. and Escherichia coli with a MIC of 16.5 microg ml(-1). EuniSL was found to be effective against bacteria. The strong antibacterial activity of the studied lectin indicates a high potential for clinical microbiology and therapeutic applications.

  17. 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.

  18. 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

  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. 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)

  1. 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)

  2. 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)

  3. 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 ...

  4. 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...

  5. 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 ...

  6. Ion exchange purification of scandium

    Science.gov (United States)

    Herchenroeder, Laurie A.; Burkholder, Harvey 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.

  7. 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

  8. 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

  9. Lysine purification with cation exchange resin

    International Nuclear Information System (INIS)

    Khayati, GH.; Mottaghi Talab, M.; Hamooni Hagheeghat, M.; Fatemi, M.

    2003-01-01

    L-lysine is an essential amino acid for the growth most of animal species and the number one limiting amino acid for poultry. After production and biomass removal by filtration and centrifugation, the essential next step is the lysine purification and recovery. There are different methods for lysine purification. The ion exchange process is one of the most commonly used purification methods. Lysine recovery was done from broth by ion exchange resin in three different ways: repeated passing, resin soaking and the usual method. Impurities were isolated from the column by repeated wash with distilled water. Recovery and purification was done with NH 4 OH and different alcohol volumes respectively. The results showed that repeated passing is the best method for lysine absorption (maximum range 86.21 %). Washing with alkali solution revealed that most of lysine is obtained in the first step of washing. The highest degree of lysine purification was achieved with the use of 4 volumes of alcohol

  10. 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.

  11. 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.

  12. Purification and characterization of Escherichia coli MreB protein.

    Science.gov (United States)

    Nurse, Pearl; Marians, Kenneth J

    2013-02-01

    The actin homolog MreB is required in rod-shaped bacteria for maintenance of cell shape and is intimately connected to the holoenzyme that synthesizes the peptidoglycan layer. The protein has been reported variously to exist in helical loops under the cell surface, to rotate, and to move in patches in both directions around the cell surface. Studies of the Escherichia coli protein in vitro have been hampered by its tendency to aggregate. Here we report the purification and characterization of native E. coli MreB. The protein requires ATP hydrolysis for polymerization, forms bundles with a left-hand twist that can be as long as 4 μm, forms sheets in the presence of calcium, and has a critical concentration for polymerization of 1.5 μM.

  13. Purification and Characterization of Escherichia coli MreB Protein*

    Science.gov (United States)

    Nurse, Pearl; Marians, Kenneth J.

    2013-01-01

    The actin homolog MreB is required in rod-shaped bacteria for maintenance of cell shape and is intimately connected to the holoenzyme that synthesizes the peptidoglycan layer. The protein has been reported variously to exist in helical loops under the cell surface, to rotate, and to move in patches in both directions around the cell surface. Studies of the Escherichia coli protein in vitro have been hampered by its tendency to aggregate. Here we report the purification and characterization of native E. coli MreB. The protein requires ATP hydrolysis for polymerization, forms bundles with a left-hand twist that can be as long as 4 μm, forms sheets in the presence of calcium, and has a critical concentration for polymerization of 1.5 μm. PMID:23235161

  14. 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 ...

  15. 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.

  16. 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.

  17. 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.

  18. 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

    2013-05-07

    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.

  19. 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.

  20. 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 ...

  1. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

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

    African Journals Online (AJOL)

    Affinity purification of recombinant human plasminogen activator from ... Screening antibody was performed using rhPA milk in an ELISA-elution assay. ... useful for purifying other tPA mutants or other novel recombinant milkderived proteins.

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

    African Journals Online (AJOL)

    SAM

    2014-06-04

    Jun 4, 2014 ... 2Department of Food Technology, Erzurum Vocational Training School, Ataturk University, 25240, ... facultative anaerobic, catalase-negative, immobile (with ..... Partial purification of phytase from a soil isolate bacterium,.

  4. Purification and Characterization of Thermostable Cellulase from ...

    African Journals Online (AJOL)

    Available online at http://www.tjpr.org ... Methods: Molecular community structure of the newly selected thermophilic bacterial ... Keywords: Thermostable cellulase, Sugarcane bagasse, Purification, Characterization, Hot spring ... Currently, one.

  5. 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.

  6. Extraction and purification of yellow cake

    International Nuclear Information System (INIS)

    Yousif, E.H.

    2006-01-01

    This dissertation has reviewed current studies on production and purification of yellow cake from uranium ores by both acid and alkaline leaching processes. It comprises three chapters, the first one deal with uranium minerals, uranium deposits, geology of uranium and uranium isotopes. The second chapter covers mining and milling methods, uranium leaching chemistry, precipitation, and purification of uranium concentrate by solvent extraction and possible impurities that commonly interfered with yellow cake. The last chapter presented ongoing literature review.(Author)

  7. Multipartite electronic entanglement purification with charge detection

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Yubo [Department of Physics, Tsinghua University, Beijing 100084 (China); Deng, Fu-Guo [Department of Physics, Beijing Normal University, Beijing 100875 (China); Long Guilu, E-mail: gllong@tsinghua.edu.c [Department of Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory for Atomic and Molecular NanoSciences, Tsinghua University, Beijing 100084 (China); Tsinghua National Laboratory for Information Science and Technology, Beijing 100084 (China)

    2011-01-17

    We present a multipartite entanglement purification scheme in a Greenberger-Horne-Zeilinger state for electrons based on their spins and their charges. This scheme works for purification with two steps, i.e., bit-flip error correction and phase-flip error correction. By repeating these two steps, the parties in quantum communication can get some high-fidelity multipartite entangled electronic systems.

  8. 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

  9. 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.

  10. 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.

  11. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Manner, H; Nissen, M

    1999-12-31

    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

  13. 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

  14. Effect of metal nanoparticles on energy spectra and optical properties of peripheral light-harvesting LH2 complexes from photosynthetic bacteria

    International Nuclear Information System (INIS)

    Goliney, I.Yu.; Sugakov, V.I.; Valkunas, L.; Vertsimakha, G.V.

    2012-01-01

    Highlights: ► Excitons of light-harvesting complexes (LH2) hybridize with plasmon modes. ► Light absorption of LH2 is enhanced by a metal nanoparticle. ► Using nanoshells allows reaching resonance between molecular and plasmons. ► Metal nanoparticles introduce additional channel of excitation decay. ► Light-harvesting may gain from the proper positioning of nanoshells. -- Abstract: The paper explores the theoretical possibility of affecting optical spectra and the quantum yield of the energy transfer in the peripheral light-harvesting complexes (LH2) from photosynthetic bacteria by placing a metal nanoparticle or a nanoshell nearby. An increased probability of the excitonic transition in the LH2 arises due to the borrowing of the oscillator strength from surface plasmons of the metal particle or the nanoshell. While both absorption and quenching of the excitations increase in the vicinity to a metal nanoparticle, having opposite effects, the total yield of the excitation transfer to reaction centers is shown to grow in the certain range of parameters.

  15. Effect of metal nanoparticles on energy spectra and optical properties of peripheral light-harvesting LH2 complexes from photosynthetic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Goliney, I.Yu., E-mail: igoliney@kinr.kiev.ua [Institute for Nuclear Research, National Academy of Science of Ukraine, 47 Nauki pr., 03680 Kyiv (Ukraine); Sugakov, V.I. [Institute for Nuclear Research, National Academy of Science of Ukraine, 47 Nauki pr., 03680 Kyiv (Ukraine); Valkunas, L. [Center for Physical Sciences and Technology, Savanoriu Ave. 231, 02300 Vilnius (Lithuania); Department of Theoretical Physics, Vilnius University, Sauletekio 9, Build. 3, 10222 Vilnius (Lithuania); Vertsimakha, G.V. [Institute for Nuclear Research, National Academy of Science of Ukraine, 47 Nauki pr., 03680 Kyiv (Ukraine)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Excitons of light-harvesting complexes (LH2) hybridize with plasmon modes. Black-Right-Pointing-Pointer Light absorption of LH2 is enhanced by a metal nanoparticle. Black-Right-Pointing-Pointer Using nanoshells allows reaching resonance between molecular and plasmons. Black-Right-Pointing-Pointer Metal nanoparticles introduce additional channel of excitation decay. Black-Right-Pointing-Pointer Light-harvesting may gain from the proper positioning of nanoshells. -- Abstract: The paper explores the theoretical possibility of affecting optical spectra and the quantum yield of the energy transfer in the peripheral light-harvesting complexes (LH2) from photosynthetic bacteria by placing a metal nanoparticle or a nanoshell nearby. An increased probability of the excitonic transition in the LH2 arises due to the borrowing of the oscillator strength from surface plasmons of the metal particle or the nanoshell. While both absorption and quenching of the excitations increase in the vicinity to a metal nanoparticle, having opposite effects, the total yield of the excitation transfer to reaction centers is shown to grow in the certain range of parameters.

  16. 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

  17. 75__Abdulazeez_Partial purification

    African Journals Online (AJOL)

    User

    therapeutic target in the treatment ofhypertensi. Common ... The peptide contained seventeen amino acids g/100g ... based on the swelling and solubility properties, ..... assay and properties of angiotensin converting enzyme from rabbit lungs.

  18. Development of a Chemically Defined Medium for Better Yield and Purification of Enterocin Y31 from Enterococcus faecium Y31

    OpenAIRE

    Liu, Wenli; Zhang, Lanwei; Yi, Huaxi

    2017-01-01

    The macro- and micronutrients in traditional medium, such as MRS, used for cultivating lactic acid bacteria, especially for bacteriocin production, have not been defined, preventing the quantitative monitoring of metabolic flux during bacteriocin biosynthesis. To enhance Enterocin Y31 production and simplify steps of separation and purification, we developed a simplified chemically defined medium (SDM) for the growth of Enterococcus faecium Y31 and production of its bacteriocin, Enterocin Y31...

  19. 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.

  20. 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.

  1. Biological response to purification and acid functionalization of carbon nanotubes

    Science.gov (United States)

    Figarol, Agathe; Pourchez, Jérémie; Boudard, Delphine; Forest, Valérie; Tulliani, Jean-Marc; Lecompte, Jean-Pierre; Cottier, Michèle; Bernache-Assollant, Didier; Grosseau, Philippe

    2014-07-01

    Acid functionalization has been considered as an easy way to enhance the dispersion and biodegradation of carbon nanotubes (CNT). However, inconsistencies between toxicity studies of acid functionalized CNT remain unexplained. This could be due to a joint effect of the main physicochemical modifications resulting from an acid functionalization: addition of surface acid groups and purification from catalytic metallic impurities. In this study, the impact on CNT biotoxicity of these two physiochemical features was assessed separately. The in vitro biological response of RAW 264.7 macrophages was evaluated after exposure to 15-240 µg mL-1 of two types of multi-walled CNT. For each type of CNT (small: 20 nm diameter, and big: 90 nm diameter), three different surface chemical properties were studied (total of six CNT samples): pristine, acid functionalized and desorbed. Desorbed CNT were purified by the acid functionalization but presented a very low amount of surface acid groups due to a thermal treatment under vacuum. A Janus effect of acid functionalization with two opposite impacts is highlighted. The CNT purification decreased the overall toxicity, while the surface acid groups intensified it when present at a specific threshold. These acid groups especially amplified the pro-inflammatory response. The threshold mechanism which seemed to regulate the impact of acid groups should be further studied to determine its value and potential link to the other physicochemical state of the CNT. The results suggest that, for a safer-design approach, the benefit-risk balance of an acid functionalization has to be considered, depending on the CNT primary state of purification. Further research should be conducted in this direction.

  2. 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.

  3. 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.

  4. Purification of Drinking Water from Fluorides by Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    Aleksander A.

    2018-03-01

    Full Text Available Introduction: An important task in the sphere of sanitary and epidemiological welfare of the population of the Russian Federation is provision of drinking water. Tap water must not contain pathogenic bacteria and dangerous chemicals. Purification systems regulate the concentration of fluoride ions in drinking water. The aim of this paper is to study the possibility of purifying tap water from fluoride ions by reverse osmosis. Materials and Methods: We used the Alfa Laval PilotUnit 2.5 "RO/NF with a set of spiral-type membrane elements RO99-2517/48 to remove fluoride ions. We measured the concentration of fluoride ions by the potentiometric method using the Hanna HI 2211 (pH/mV/T. Fluoride-selective electrode ELIS 131 F was used as an indicator electrode and the standard chloride-silver electrode EVL-1M3 was used as a reference electrode. Both the calibration and buffer solutions were prepared from chemically pure reagents and A. R. purity for analysis reagents according to GOST 4386-89. Results: A single passage of water through the reverse osmosis membrane reduced the concentration of fluoride ions from 2.29 ± 0.02 to 0.240 ± 0.015 mg/l. Double passage of water reduced the concentration by a factor of two. As the concentration of fluoride ions increased in the retentate, the concentration in the filtrate slightly increased too. Purification of water reduced the concentration of fluoride ions from 20 mg/l, to 0.5 mg/l. Discussion and Conclusions: Thus, using the Alfa Laval PilotUnit 2.5" RO/NF with a set of spiral-type membrane elements RO99-2517/48 filters tap water of ions of fluoride to the maximum allowable concentration. This study opens the perspective of using reverse osmosis to purify tap water with high concentration of fluoride ions.

  5. Studies on Brucella interferon: Chromatographic behaviour and purification

    International Nuclear Information System (INIS)

    Bousquet-Ucla, C.; Wietzerbin, J.; Falcoff, E.

    1980-01-01

    Interferon was induced by infecting mice with Brucella suis. Serum containing interferon activity was analyzed by chromatography on Concanavalin A-Sepharose and Phenyl-Sepharose CL-4B columns. Antiviral activity was completely retained by the lectin column indicating that all the interferon molecules are glycosylated. The chromatographic behaviour of Brucella interferon on Phenyl-Sepharose CL-4B show that, like other interferons, Brucella interferon displays hydrophobic properties. However, the hydrophobicity of the interferon molecule was masked in the crude preparation and was only detectable when purified Brucella interferon was used for chromatography. The antigenic properties of Brucella interferon provided the means for developing an affinity chromatographic method resulting in about 60.000 fold purification. As in the case of viral interferon, treatment of L cells with Brucella interferon induced specific enhanced in vitro phosphorylation of a 67.000 molecular weight protein after incubation of cell extracts with doublestranded RNA and [γ- 32 p]ATP. (auth.)

  6. Purification of crude biodiesel using dry washing and membrane technologies

    OpenAIRE

    Atadashi, I.M.

    2015-01-01

    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-quali...

  7. Solvent-extraction purification of neptunium

    International Nuclear Information System (INIS)

    Kyser, E.A.; Hudlow, S.L.

    2008-01-01

    The Savannah River Site (SRS) has recovered 237 Np from reactor fuel that is currently being processed into NpO 2 for future production of 238 Pu. Several purification flowsheets have been utilized. An oxidizing solvent-extraction (SX) flowsheet was used to remove Fe, sulfate ion, and Th while simultaneously 237 Np, 238 Pu, u, and nonradioactive Ce(IV) was extracted into the tributyl phosphate (TBP) based organic solvent. A reducing SX flowsheet (second pass) removed the Ce and Pu and recovered both Np and U. The oxidizing flowsheet was necessary for solutions that contained excessive amounts of sulfate ion. Anion exchange was used to perform final purification of Np from Pu, U, and various non-actinide impurities. The Np(IV) in the purified solution was then oxalate-precipitated and calcined to an oxide for shipment to other facilities for storage and future target fabrication. Performance details of the SX purification and process difficulties are discussed. (authors)

  8. Recombinant Expression and Purification of the Shigella Translocator IpaB.

    Science.gov (United States)

    Barta, Michael L; Adam, Philip R; Dickenson, Nicholas E

    2017-01-01

    Type III secretion systems (T3SS) are highly conserved virulence factors employed by a large number of pathogenic gram-negative bacteria. Like many T3SS translocators, recombinant expression of the hydrophobic Shigella protein IpaB requires the presence of its cognate chaperone IpgC. Chaperone-bound IpaB is maintained in a nonfunctional state, which has hampered in vitro studies aimed at understanding molecular structure and function of this important class of T3SS proteins. Herein, we describe an expression and purification protocol that utilizes mild detergents to produce highly purified, homogeneous IpaB of defined oligomeric states.

  9. 21 CFR 876.5665 - Water purification system for hemodialysis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Water purification system for hemodialysis. 876... SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5665 Water purification system for hemodialysis. (a) Identification. A water purification system for hemodialysis is a...

  10. 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

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

    Science.gov (United States)

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

    2015-11-01

    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.

  12. 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.

  13. 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.

  14. 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.

  15. Venturi purification device and its application in purification of gaseous waste of nuclear facilities

    International Nuclear Information System (INIS)

    Kong Jinsong; Yu Ren; Yang Huanlei

    2013-01-01

    The working principle of Venturi purification device and its purification of aerosol have been described. Then, taking the gaseous iodine as an example, the absorption process of insoluble gas pollutants is discussed, the calculation methods of the gas-liquid contact area, mass transfer rate and efficiency of mass transfer are educed, and the factors that affect the efficiency of mass transfer are analyzed. (authors)

  16. 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.

  17. 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 ...

  18. 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 ...

  19. Purification and characterization of protease enzyme from ...

    African Journals Online (AJOL)

    user

    2013-03-20

    Mar 20, 2013 ... Full Length Research Paper. Purification and ... ting into small peptides and free amino acids, which can ... Isolated strain was cultured in synthetic medium- casein (SMC; ... Protease activity was assayed by sigma's non-specific protease ... following buffers: 0.05 M citrate-phosphate buffer (pH 5 to 6), Tris-.

  20. 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 ...

  1. Expression and Purification of Sperm Whale Myoglobin

    Science.gov (United States)

    Miller, Stephen; Indivero, Virginia; Burkhard, Caroline

    2010-01-01

    We present a multiweek laboratory exercise that exposes students to the fundamental techniques of bacterial expression and protein purification through the preparation of sperm whale myoglobin. Myoglobin, a robust oxygen-binding protein, contains a single heme that gives the protein a reddish color, making it an ideal subject for the teaching…

  2. Biodiesel separation and purification: A review

    International Nuclear Information System (INIS)

    Atadashi, I.M.; Aroua, M.K.; Aziz, A. Abdul

    2011-01-01

    Biodiesel as a biodegradable, sustainable and clean energy has worldwide attracted renewed and growing interest in topical years, chiefly due to development in biodiesel fuel and ecological pressures which include climatic changes. In the production of biodiesel from biomass, separation and purification of biodiesel is a critical technology. Conventional technologies used for biodiesel separation such as gravitational settling, decantation, filtration and biodiesel purification such as water washing, acid washing, and washing with ether and absorbents have proven to be inefficient, time and energy consumptive, and less cost effective. The involvement of membrane reactor and separative membrane shows great promise for the separation and purification of biodiesel. Membrane technology needs to be explored and exploited to overcome the difficulties usually encountered in the separation and purification of biodiesel. In this paper both conventional and most recent membrane technologies used in refining biodiesel have been critically reviewed. The effects of catalysts, free fatty acids, water content and oil to methanol ratios on the purity and quality of biodiesel are also examined. (author)

  3. Zone distillation: a new purification method

    International Nuclear Information System (INIS)

    Kravchenko, A.I.

    2011-01-01

    The features of zone distillation (with zone melting of refined material and with pulling of condensate) as a new purification method are shown. The method is based on similarity of equations of distillation and crystallization refining. The analogy between some distillation and condensation methods (particularly between zone distillation and zone recrystallization) is should up

  4. 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.

  5. Cost-effective expression and purification of antimicrobial and host defense peptides in Escherichia coli

    DEFF Research Database (Denmark)

    Bommarius, B.; Jenssen, Håvard; Elliott, M.

    2010-01-01

    Cationic antimicrobial host defense peptides (HDPs) combat infection by directly killing a wide variety of microbes, and/or modulating host immunity. HDPs have great therapeutic potential against antibioticresistant bacteria, viruses and even parasites, but there are substantial roadblocks......, we describe (i) a method, using fusions to SUMO, for producing high yields of intact recombinant HDPs in bacteria without significant toxicity and (ii) a simplified 2-step purification method appropriate for industrial use. We have used this method to produce seven HDPs to date (IDR1, MX226, LL37......, CRAMP, HHC-10, E5 and E6). Using this technology, pilot-scale fermentation (10 L) was performed to produce large quantities of biologically active cationic peptides. Together, these data indicate that this new method represents a cost-effective means to enable commercial enterprises to produce HDPs...

  6. 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.

  7. 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

  8. Copper tolerance and virulence in bacteria

    Science.gov (United States)

    Ladomersky, Erik; Petris, Michael J.

    2015-01-01

    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  9. Stability and properties of quasi-stable conformational states in the LH2 light-harvesting complex of Rbl. acidophilus bacteria formed by hexacoordination of bacteriochlorophyll a magnesium atom

    Science.gov (United States)

    Belov, Aleksandr S.; Khokhlov, Daniil V.; Glebov, Ilya O.; Poddubnyy, Vladimir V.; Eremin, Vadim V.

    2017-06-01

    Single-molecule spectroscopic experiments on several light-harvesting complexes revealed the existence of a set of metastable conformational states with different spectroscopic properties and lifetimes spanning from milliseconds to tens of seconds. In the absence of explicit structural data, a number of probable structural changes underlying the observed spectroscopic shifts were proposed. We examine the donor-acceptor interaction between the magnesium atom and the acetyl group of the adjacent bacteriochlorophylls a as a possible origin of metastable conformational states in the LH2 light-harvesting complex of Rbl. acidophilus bacteria. The results of QM/MM and molecular dynamics simulations show that such ligation can occur at room temperature and leads to one metastable coordination bond per pair of bacteriochlorophylls in the B850 ring. According to the results of Poisson-TrESP modeling, such coordination lowers the energies of the excited states of the complex by up to 163 cm-1 which causes red spectral shift of the B850 band.

  10. 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...

  11. Do Bacteria Age?

    Indian Academy of Sciences (India)

    Bacteria are thought to be examples of organisms that do not age. They divide by .... carry genetic material to the next generation through the process of reproduction; they are also .... molecules, and modified proteins. This report revealed that ...

  12. Social Behaviour in Bacteria

    Indian Academy of Sciences (India)

    Administrator

    the recipient. • Social behaviours can be categorized according to the fitness ... is actually the flagella of symbiotic spirochete bacteria that helps it to swim around .... Normal population. Responsive switching. (Environmental stress). Stochastic.

  13. [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.

  14. 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.

  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. PURIFICATION AND ENRICHMENT OF BIOGAS IN ASH-WATER MIXTURE

    Directory of Open Access Journals (Sweden)

    Andrzej Brudniak

    2014-10-01

    Full Text Available Biogas, produced in an aerobic digestion process, is a mixture of gases, and that is why its inexpensive and effective valorisation is essential. Research on this process is necessary in order to use biogas as a renewable energy source. The aim of this thesis is to present methods of biogas purification and enrichment in the fly ash - water mixture, that is generated on the base of fly ash produced during burning coal in power industry. Experience presented that the fly ash absorbs CO2 and H2S, even in conventional conditions. The absorption efficiency depends not only on the chemical composition of the ash but also on its physical properties. There was also a strong neutralization of alkaline waste combustion.

  17. Lipopolysaccharides in diazotrophic bacteria

    OpenAIRE

    Serrato, Rodrigo V.

    2014-01-01

    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are...

  18. Lipopolysaccharides in diazotrophic bacteria.

    Science.gov (United States)

    Serrato, Rodrigo V

    2014-01-01

    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  19. 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...

  20. 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

  1. Denitrification of acid wastes from uranium purification processes

    International Nuclear Information System (INIS)

    Clark, F.E.; Francis, C.W.; Francke, H.C.; Strohecker, J.W.

    1975-11-01

    Laboratory and pilot-plant investigations have shown the technical feasibility of removing nitrates from neutralized acid wastes from uranium purification processes by biological denitrification, a dissimilatory process in which the nitrate ion is reduced to nitrogen gas by specific bacteria. The process requires anaerobic conditions and an organic carbon source, as well as other life-sustaining constituents. These denitrification studies produced process design information on a columnar denitrification plant and on continuous-flow, stirred-bed reactors. Denitrification, using packed columns, was found to be desirable for soluble salts, such as those of sodium and ammonium; denitrification, using stirred reactors, was found to be desirable for mixtures containing insoluble salts, such as those of calcium and aluminum. Packed columns were found to have denitrification rates ranging up to 122 grams of nitrate per day per cubic decimeter of column volume; stirred-bed reactors have been shown to have reaction rates near 10 grams of nitrate per day per cubic decimeter of reactor volume. The continuous-flow, stirred-bed reactors were selected for scaleup studies because of the solids-removal problems associated with packed columns when operating on feeds containing high concentrations of insoluble salts or ions which form insoluble salts with the products of the denitrification reaction

  2. Expression and Purification of Neurotrophin-Elastin-Like Peptide Fusion Proteins for Neural Regeneration.

    Science.gov (United States)

    Johnson, Tamina; Koria, Piyush

    2016-04-01

    Neural injuries such as spinal cord injuries, traumatic brain injuries, or nerve transection injuries pose a major health problem. Neurotrophins such as nerve growth factor (NGF) or brain-derived neurotrophic factor (BDNF) have been shown to improve the outcome of neural injuries in several pre-clinical models, but their use in clinics is limited by the lack of a robust delivery system that enhances their bioavailability and half-life. We describe two fusion proteins comprising NGF or BDNF fused with elastin-like peptides (ELPs). The aim of this study was to investigate the biological activity of neurotrophin-ELP (N-ELP) fusion proteins via in vitro culture models. NGF and BDNF were cloned in front of an elastin-like polypeptide sequence V40C2. These proteins were expressed in bacteria as inclusion bodies. These fusion proteins underwent solubilization via 8 M urea and purification via inverse transition cycling (ITC). We measured the particle size and the effect of temperature on precipitated particles using dynamic light scattering (DLS). We used western blot analysis to confirm the specificity of NGF-ELP to tropomyosin receptor kinase A (TrkA) antibody and to confirm the specificity of BDNF-ELP to TrkB antibody. PC12 cells were used to perform a neurite outgrowth assay to determine the biological activity of NGF-ELP. Bioactivity of BDNF-ELP was ascertained via transfecting human epithelial kidney (HEK 293-T) cells to express the TrkB receptor. The proteins were successfully purified to high homogeneity by exploiting the phase transition property of ELPs and urea, which solubilize inclusion bodies. Using PC12 neurite outgrowth assay, we further demonstrated that the biological activity of NGF was retained in the fusion. Similarly, BDNF-ELP phosphorylated the TrkB receptor, suggesting the biological activity of BDNF was also retained in the fusion. We further show that owing to the phase transition property of ELPs in the fusion, these proteins self-assembled into

  3. Marine Actinomycetes screening of Banten West Coast and their antibiotics purification

    Directory of Open Access Journals (Sweden)

    ROFIQ SUNARYANTO

    2010-10-01

    Full Text Available Sunaryanto R, Marwoto B (2010 Marine Actinomycetes screening of Banten West Coast and their antibiotics purification. Biodiversitas 11: 176-181. Isolation and purification of active compounds produced by marine Actinomycetes has been carried out. Marine sediment samples were obtained from six different places at Anyer, Banten West Coast in October 20, 2007. Isolation was carried out using two methods pretreatments, acid treatment and heat shock treatment. A total of 29 Actinomycetes isolates were obtained from the various sediment samples collected, then tested for antimicrobial test against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC25923, Pseudomonas aeruginosa ATCC27853, Bacillus subtilis ATCC 66923, Candida albicans BIOMCC00122 and Aspergillus niger BIOMCC00134. Identification of potential isolate was carried out using 16S rRNA. Purification of active compound was carried out using silica gel column chromatography and preparative HPLC. Result of this research showed that isolate A11 produced the most active compound against Gram-positive and Gram-negative bacteria. Morphology and identification test using 16S rRNA gen showed that isolate A11 is Streptomyces sp. Production of active compound from isolate A11 used yeast peptone medium. The single peak of active compound was detected by HPLC and showed retention time on 8.35 min and maximum absorbance UV visible of antibiotic was 210 nm and 274.5 nm. Active purified compound showed inhibition activity to Gram-positive and Gram-negative bacteria. Minimum inhibitory concentration (MIC to E. coli ATCC 25922 was 27 µg/mL, P. aeruginosa ATCC 27853 68.7 µg/mL, S. aureus ATCC 25923 80.2 µg/mL, and B. subtilis ATCC 66923 73.7 µg/mL.

  4. Property.

    Science.gov (United States)

    Piele, Philip K.

    Numerous cases in this year's chapter dealt with the same topics of previous years--contracts and bids for building construction, and detachment and annexation of a portion of a school district. The courts continued to attribute board discretionary authority to school boards in school property matters. Intergovernmental disputes over ownership or…

  5. 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

  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. Behavior of pathogenic bacteria in the oyster, Crassostrea commercialis, during depuration, re-laying, and storage.

    OpenAIRE

    Son, N T; Fleet, G H

    1980-01-01

    Oysters (Crassostrea commercials) harvested from major cultivation areas within the state of New South Wales, Australia, were commonly contaminated with low levels of the food-poisoning organisms Bacillus cereus, Clostridium perfringens, and Vibrio parahaemolyticus. Salmonella was found in oysters on only one occasion. These bacteria were cleansed from oysters during oyster purification by re-laying in a non-polluted waterway. Oysters were laboratory contaminated to levels in excess 1,000 cel...

  8. 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 ...

  9. 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.

  10. Extracellular deoxyribonuclease production by periodontal bacteria.

    Science.gov (United States)

    Palmer, L J; Chapple, I L C; Wright, H J; Roberts, A; Cooper, P R

    2012-08-01

    Whilst certain bacteria have long been known to secrete extracellular deoxyribonuclease (DNase), the purpose in microbial physiology was unclear. Recently, however, this enzyme has been demonstrated to confer enhanced virulence, enabling bacteria to evade the host's immune defence of extruded DNA/chromatin filaments, termed neutrophil extracellular traps (NETs). As NETs have recently been identified in infected periodontal tissue, the aim of this study was to screen periodontal bacteria for extracellular DNase activity. To determine whether DNase activity was membrane bound or secreted, 34 periodontal bacteria were cultured in broth and on agar plates. Pelleted bacteria and supernatants from broth cultures were analysed for their ability to degrade DNA, with relative activity levels determined using an agarose gel electrophoresis assay. Following culture on DNA-supplemented agar, expression was determined by the presence of a zone of hydrolysis and DNase activity related to colony size. Twenty-seven bacteria, including red and orange complex members Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Streptococcus constellatus, Campylobacter rectus and Prevotella nigrescens, were observed to express extracellular DNase activity. Differences in DNase activity were noted, however, when bacteria were assayed in different culture states. Analysis of the activity of secreted DNase from bacterial broth cultures confirmed their ability to degrade NETs. The present study demonstrates, for the first time, that DNase activity is a relatively common property of bacteria associated with advanced periodontal disease. Further work is required to determine the importance of this bacterial DNase activity in the pathogenesis of periodontitis. © 2011 John Wiley & Sons A/S.

  11. 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.

  12. 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.

  13. Development of partitioning process: purification of DIDPA

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masayuki; Morita, Yasuji; Kubota, Masumitsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    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)

  14. 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....

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. The Use of Bacteria for Remediation of Mercury Contaminated Groundwater

    Science.gov (United States)

    Many processes of mercury transformation in the environment are bacteria mediated. Mercury properties cause some difficulties of remediation of mercury contaminated environment. Despite the significance of the problem of mercury pollution, methods of large scale bioremediation ...

  5. 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.

  6. Entanglement purification of multi-mode quantum states

    International Nuclear Information System (INIS)

    Clausen, J; Knoell, L; Welsch, D-G

    2003-01-01

    An iterative random procedure is considered allowing entanglement purification of a class of multi-mode quantum states. In certain cases, complete purification may be achieved using only a single signal state preparation. A physical implementation based on beam splitter arrays and non-linear elements is suggested. The influence of loss is analysed in the example of purification of entangled N-mode coherent states

  7. 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...

  8. Water purification from radionuclides with using fibroid sorbents

    International Nuclear Information System (INIS)

    Khaydarov, R. A.; Gapurova, O.U.; Khaydarov, R.R.

    2005-01-01

    Full text: Purification waste water and drinking water from radionuclides, heavy metal ions, organic contamination is one of the important problems today. For solving this problem we have created three types of fibroid sorbents on the base of Polyester: cationic and anionic exchange and carbonic. Main properties of these sorbents are described in this article. For example characteristics of the sorbents for removing radionuclides Co-60,57, Zn-65, Sr-89,90, Cs-134,137, etc., radionuclides containing organic molecules M-P-32, M-I-131, M-Mo-99+Tc-99m, M-C-14, etc., heavy metal ions Zn, Ni, Cu, Sb, Pb, Cd, Cr, U, etc., organic molecules (pesticides, phenols, dioxin, benzene, toluene, etc.) were investigated. Influence of pH on percent removal, influence of K, Na and another ions concentrations in the liquid on the percent removal, decreasing of the saturation capacity from number of regeneration and another characteristics are described. Static exchange capacity of the cationic sorbents is 1-2 mg-equ/g and anionic - 0.5-1 mg-equ/g. Capacity of the carbonic sorbents for benzene is 100 mg/g. Time of chemical balance setting is 1-2 s. The sorbents are effective in removing the low concentrations of contamination from the water (lower than 100-200 mg/l) and the air (lower than 100 mg/m 3 ). The use of sorbents in drinking water filters and mini-systems is described. The industrial water purification system consists of coagulating unit, sorbent unit and disinfectant unit. The systems are used in atomic power stations, electroplating plants, matches plants, leather and skin treating plants, car-washing stations, etc

  9. 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.

  10. Large-scale purification and in vitro characterization of the assembly of MreB from Leptospira interrogans.

    Science.gov (United States)

    Barkó, Szilvia; Szatmári, Dávid; Bódis, Emőke; Türmer, Katalin; Ujfalusi, Zoltán; Popp, David; Robinson, Robert C; Nyitrai, Miklós

    2016-09-01

    Weil's syndrome is caused by Leptospira interrogans infections, a Gram negative bacterium with a distinct thin corkscrew cell shape. The molecular basis for this unusual morphology is unknown. In many bacteria, cell wall synthesis is orchestrated by the actin homolog, MreB. Here we have identified the MreB within the L. interrogans genome and expressed the His-tagged protein product of the synthesized gene (Li-MreB) in Escherichia coli. Li-MreB did not purify under standard nucleotide-free conditions used for MreBs from other species, requiring the continual presence of ATP to remain soluble. Covalent modification of Li-MreB free thiols with Alexa488 produced a fluorescent version of Li-MreB. We developed native and denaturing/refolding purification schemes for Li-MreB. The purified product was shown to assemble and disassemble in MgCl2 and KCl dependent manners, as monitored by light scattering and sedimentation studies. The fluorescence spectrum of labeled Li-MreB-Alexa488 showed cation-induced changes in line with an activation process followed by a polymerization phase. The resulting filaments appeared as bundles and sheets under the fluorescence microscope. Finally, since the Li-MreB polymerization was cation dependent, we developed a simple method to measure monovalent cation concentrations within a test case prokaryote, E. coli. We have identified and initially characterized the cation-dependent polymerization properties of a novel MreB from a non-rod shaped bacterium and developed a method to measure cation concentrations within prokaryotes. This initial characterization of Li-MreB will enable future structural determination of the MreB filament from this corkscrew-shaped bacterium. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. 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...

  12. 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.

  13. 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)

    1999-12-31

    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.)

  14. 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.)

  15. Communication among Oral Bacteria

    Science.gov (United States)

    Kolenbrander, Paul E.; Andersen, Roxanna N.; Blehert, David S.; Egland, Paul G.; Foster, Jamie S.; Palmer, Robert J.

    2002-01-01

    Human oral bacteria interact with their environment by attaching to surfaces and establishing mixed-species communities. As each bacterial cell attaches, it forms a new surface to which other cells can adhere. Adherence and community development are spatiotemporal; such order requires communication. The discovery of soluble signals, such as autoinducer-2, that may be exchanged within multispecies communities to convey information between organisms has emerged as a new research direction. Direct-contact signals, such as adhesins and receptors, that elicit changes in gene expression after cell-cell contact and biofilm growth are also an active research area. Considering that the majority of oral bacteria are organized in dense three-dimensional biofilms on teeth, confocal microscopy and fluorescently labeled probes provide valuable approaches for investigating the architecture of these organized communities in situ. Oral biofilms are readily accessible to microbiologists and are excellent model systems for studies of microbial communication. One attractive model system is a saliva-coated flowcell with oral bacterial biofilms growing on saliva as the sole nutrient source; an intergeneric mutualism is discussed. Several oral bacterial species are amenable to genetic manipulation for molecular characterization of communication both among bacteria and between bacteria and the host. A successful search for genes critical for mixed-species community organization will be accomplished only when it is conducted with mixed-species communities. PMID:12209001

  16. PATHOGENICITY OF BIOFILM BACTERIA

    Science.gov (United States)

    There is a paucity of information concerning any link between the microorganisms commonly found in biofilms of drinking water systems and their impacts on human health. For bacteria, culture-based techniques detect only a limited number of the total microorganisms associated wit...

  17. Bacteria-surface interactions.

    Science.gov (United States)

    Tuson, Hannah H; Weibel, Douglas B

    2013-05-14

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  18. 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 ...

  19. Design and control of an alternative distillation sequence for bioethanol purification

    DEFF Research Database (Denmark)

    Errico, Massimiliano; Ramírez-Márquez, César; Torres Ortega, Carlo Edgar

    2015-01-01

    BACKGROUND: Bioethanol is a green fuel considered to be a sustainable alternative to petro-derived gasoline. The transport sector contributes significantly to carbon dioxide emission and consequently has a negative impact on the air quality and is responsible for the increase of the greenhouse...... separation is presented. The steady state performance and the dynamic beavior are analyzed compared with the classical configuration reported in the literature. RESULTS: Ethanol-water azeotropic separation represents a challenge for bioethanol purification. Usually a three column sequence is used to obtain...... fuel grade bioethanol by extractive distillation. In order to reduce bioethanol purification cost a two column separation sequence is proposed. This configuration shows a 10% saving in capital costs together with higher ethanol recovery and better control properties compared with the classical three...

  20. Polysaccharides from Traditional Chinese Medicines: Extraction, Purification, Modification, and Biological Activity

    Directory of Open Access Journals (Sweden)

    Yun Chen

    2016-12-01

    Full Text Available 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.

  1. 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.

  2. Radiation purification of the chemical industry effluents and possibilities of realization of this method

    International Nuclear Information System (INIS)

    Petryaev, E.P.; Kovalevskaya, A.M.; Shlyk, V.G.; Savushkin, I.A.; Kazazyan, V.T.

    1977-01-01

    Radiation-chemical methods for synthetic fibre industry effluents purification from cyanides, sulphides and monomers, as well as for disinfection of circulation water and improvement in sedimental and filtering properties of waste active slurry in petrochemical industry are described. Chemical plant effluents are purified by 70-90% from cyanides at the dose rate of 0,3 - 0,5 Mrad, by 60 - 70% from sulphides and monomers at the dose of 0,2 Mrad. Circulation water of petroleum processing plant is disinfected at the dose of 0,08 Mrad; the rates of filtration and sedimentation of waste active slurry increase two and three fold, correspondingly, at the dose of 0,6 Mrad. The power of radiation sources required for the industrial realization of radiation purification of liquid wastes has been calculated

  3. 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

  4. 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...

  5. Purification and properties of enolase of human erythrocytes

    NARCIS (Netherlands)

    Hoorn, R.K.J.; Flikweert, J.P.; Staal, Gerard E.J.

    1974-01-01

    1. 1. Human erythrocyte enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) was purified I000-fold. 2. 2. The pH-optimum was at pH 6.5. The molecular weight, estimated by gel filtration, was found to be 95,000 ± 5,000. 3. 3. Electrophoresis on agar-agarose at pH 8.5 and 6.4 showed only one

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... 1Industrial Biotechnology Department, University Technology Malaysia, 81310 Skudai, Johor, Malaysia. 2Chemistry Department, University ... mental pollution and health problems to the human population. Microbial catabolism ..... Sequence diversity among related genes for recognition of specific targets ...

  7. 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).

  8. 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 ...

  9. 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

  10. Carbon nanotubes: properties, synthesis, purification, and medical applications

    Science.gov (United States)

    Eatemadi, Ali; Daraee, Hadis; Karimkhanloo, Hamzeh; Kouhi, Mohammad; Zarghami, Nosratollah; Akbarzadeh, Abolfazl; Abasi, Mozhgan; Hanifehpour, Younes; Joo, Sang Woo

    2014-08-01

    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.

  11. Improved production, purification and some properties of α-amylase ...

    African Journals Online (AJOL)

    user

    2012-10-04

    Oct 4, 2012 ... nology industries with many potential applications in food, fermentation, textile and .... Large scale production of α-amylase enzyme in a laboratory fermentor ..... induction on amylase production and low cost (Li et al.,. 2010).

  12. 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.)

  13. 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

  14. Hp Ge: Purification, crystal growth, and annealing properties

    International Nuclear Information System (INIS)

    Hall, R.N.

    1984-01-01

    The prospects for growing HP Ge crystals of increased size and purity are examined. One interesting approach is to grow dislocation-free crystals, which must then be annealed to reduce the concentration of V 2 H traps. The phenomena which occur during annealing are discussed and compared with experiment. Hydrogen, present in atomic form at the growth temperature, forms H 2 molecules during cooling, causing the effective diffusion coefficient to decrease rapidly. Models representing the reactions between H and the V 2 H, A(H, Si), and D(H,O) complexes are presented and analyzed

  15. 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 ...

  16. 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...

  17. Purification and properties of adenosine kinase from rat brain.

    Science.gov (United States)

    Yamada, Y; Goto, H; Ogasawara, N

    1980-12-04

    Adenosine kinase (ATP:adenosine 5'-phosphotransferase, EC 2.7.1.20) has been purified to apparent homogeneity from rat brain by (NH4)2SO4 fractionation, affinity chromatography on AMP-Sepharose 4B, gel filtration with Sephadex G-100, and DE-52 cellulose column chromatography. The yield was 56% of the initial activity with a final specific activity of 7.8 mumol/min per mg protein. The molecular weight was estimated as 38 000 by gel filtration with Sephadex G-100 and 41 000 by acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). The enzyme catalyzed the phosphorylation of adenosine, deoxyadenosine, arabinoadenosine, inosine and ribavirin. The activity of deoxyadenosine phosphorylation was 20% that of adenosine phosphorylation. The pH optimum profile was biphasic; a sharp pH optimum at pH 5.5 and a broad pH optimum at pH 7.5-8.5. The Km value for adenosine was 0.2 microM and the maximum activity was observed at 0.5 microM. At higher concentrations of adenosine, the activity was strongly inhibited. The Km value for ATP was 0.02 mM and that for Mg2+ was 0.1 mM. GTP, dGTP, dATP and UTP were also proved to be effective phosphate donors. Co2+ was as effective as Mg2+, and Ca2+, Mn2+ or Ni2+ showed about 50% of the activity for Mg2+. The kinase is quite unstable, but stable in the presence of a high concentration of salt; e.g., 0.15 M KCl.

  18. 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.

  19. Identification of marine methanol-utilizing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, M; Iwaki, H; Kouno, K; Inui, T

    1980-01-01

    A taxonomical study of 65 marine methanol-utilizing bacteria is described. They were Gram-negative, non-spore-forming rods with a polar flagellum and had marine bacterial properties and required vitamin B/sub 12/ for growth. All of them assimilated fructose in addition to C/sub 1/-compounds and produced acid oxidatively from fructose. Twenty-four strains assimilated only C/sub 1/-compounds. They were resistant to penicillin, oxytetracycline and 0/129 substance (Vibrio stat), and tolerant to 12% NaCl. Guanine-cytosine contents of deoxyribonucleic acid in typical strains fell in the range of 43.8 to 47.6%. Other morphological and physiological properties were almost the same as those of terrestrial methanol-utilizers. Bacteria in the first group (41 strains) were facultative methylotrophs and were divided into three subgroups by the assimilation of methylated amines, that is, subgroup I (30 strains) assimilated mono-, di- and tri-methylamine, subgroup II (9 strains) assimilated only mono-methylamine, the bacteria of subgroups I and II were named Alteromonas thalassomethanolica sp. nov. and subgroup III (2 strains) did not assimilate methylated amines, and was tentatively assigned as Alteromonas sp. The second group of bacteria (24 strains) was obligate methylotrophs, named Methylomonas thalassica sp. nov. and was divided into subgroup IV (15 strains) which assimilated mono-, di and tri-methylamine and subgroup V (9 strains) which assimilated mono-methylamine.

  20. 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

  1. Restoration and Purification of Dissolved Organic Nitrogen by Bacteria and Phytoremediation in Shallow Eutrophic Lakes Sediments

    Science.gov (United States)

    Li, Xin; Yue, Yi

    2018-06-01

    Endogenous organic nitrogen loadings in lake sediments have increased with human activity in recent decades. A 6-month field study from two disparate shallow eutrophic lakes could partly reveal these issues by analysing seasonal variations of biodegradation and phytoremediation in the sediment. This paper describes the relationship between oxidation reduction potential, temperature, microbial activity and phytoremediation in nitrogen cycling by calculation degradative index of dissolved organic nitrogen and amino acid decomposition. The index was being positive in winter and negative in summer while closely positive correlated with biodegradation. Our analysis revealed that rather than anoxic condition, biomass is the primary factor to dissolved organic nitrogen distribution and decomposition. Some major amino acids statistics also confirm the above view. The comparisons of organic nitrogen and amino acid in abundance and seasons in situ provides that demonstrated plants cue important for nitrogen removal by their roots adsorption and immobilization. In conclusion, enhanced microbial activity and phytoremediation with the seasons will reduce the endogenous nitrogen loadings by the coupled mineralization and diagenetic process.

  2. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    Balance of bacterial species in the gut · Immunosensory detection of intestinal bacteria · Pathogenic bacteria release interleukin-8 from HT-29 cells · Lactobacillus GG prevents the IL-8 release in response to pathogens · Effect of probiotic bacteria on chemokine response of epithelia to pathogens · PCR array studies in colon ...

  3. Improving the technology of purification of gas emissions petrochemical industries

    OpenAIRE

    USMANOVA R.R.; ZAIKOV G.E.

    2014-01-01

    The technology of cleaning of gas emissions flares in the production of synthetic rubber. Developed dynamic scrubber for scrubbing gas emissions. Complex studies served as the basis for the design of an air purification system of industrial premises. Purification of gas emissions before combustion in flares has significantly reduced air pollution by toxic substances.

  4. 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

  5. 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.

  6. 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 ...

  7. 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.

  8. Purification and characterization of three laccase isozymes from the ...

    African Journals Online (AJOL)

    2012-04-17

    Apr 17, 2012 ... improve wine quality by removing fermentation inhibitors so as to increase yield of ethanol (Baldrian, 2006). They have also been used .... Summary of purification of laccase isozymes from Trametes sp. HS-03a. Purification .... and kinetics of a thermostable laccase from Pycnoporus sanguineus. (SCC 108).

  9. 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.

  10. 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.

  11. Single-step affinity purification for fungal proteomics.

    Science.gov (United States)

    Liu, Hui-Lin; Osmani, Aysha H; Ukil, Leena; Son, Sunghun; Markossian, Sarine; Shen, Kuo-Fang; Govindaraghavan, Meera; Varadaraj, Archana; Hashmi, Shahr B; De Souza, Colin P; Osmani, Stephen A

    2010-05-01

    A single-step protein affinity purification protocol using Aspergillus nidulans is described. Detailed protocols for cell breakage, affinity purification, and depending on the application, methods for protein release from affinity beads are provided. Examples defining the utility of the approaches, which should be widely applicable, are included.

  12. Single-Step Affinity Purification for Fungal Proteomics ▿ †

    OpenAIRE

    Liu, Hui-Lin; Osmani, Aysha H.; Ukil, Leena; Son, Sunghun; Markossian, Sarine; Shen, Kuo-Fang; Govindaraghavan, Meera; Varadaraj, Archana; Hashmi, Shahr B.; De Souza, Colin P.; Osmani, Stephen A.

    2010-01-01

    A single-step protein affinity purification protocol using Aspergillus nidulans is described. Detailed protocols for cell breakage, affinity purification, and depending on the application, methods for protein release from affinity beads are provided. Examples defining the utility of the approaches, which should be widely applicable, are included.

  13. 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; ...

  14. Development of Purification Protocol Specific for Bacteriocin 105B

    Science.gov (United States)

    2017-02-09

    Bacillus anthracis. As the current application of broad-spectrum antimicrobials promotes the development of multi- drug resistant microorganisms...SPECTRUM TARGETED ANTIMICROBIALS ASSAYS PURIFICATION BACILLUS ANTHRACIS DRUG- RESISTANT MICROORGANISMS...through the purification procedure. The wide-spread use of broad-spectrum antimicrobial agents has led to the development of drug resistant

  15. 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...

  16. 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...

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

    African Journals Online (AJOL)

    USER

    Keywords: Protease, lactic acid bacteria, Pediococcus acidilactici, enzyme ... confers organoleptic improvements in fermented foods ... was characterized by studying the effect of substrate ... addition of solid ammonium sulphate up to 80%.

  18. 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

  19. [Purification of 67Cu]. Progress report

    International Nuclear Information System (INIS)

    DeNardo, S.J.

    1994-01-01

    This report documents progress made in several areas of research and describes results which have not yet been published. These areas include: Purification of 67 Cu; Macrocyclic chelates for targeted therapy; Studies of biologic activation associated with molecular receptor increase and tumor response in ChL6/L6 protocol patients; Lym-1 single chain genetically engineered molecules; Analysis of molecular genetic coded messages to enhance tumor response; Human dosimetry and therapeutic human use radiopharmaceuticals; studies in phantoms; Quantitative SPECT; Preclinical studies; and Clinical studies

  20. Process for purification of gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, S Z; Letitschevskij, V I; Maergojz, I I; Michailov, L A; Puschkarev, L I

    1977-06-23

    The process relates to the purification of gas mixtures of N, H, and Ar, or N and H, or N and O which contain CO, CO/sub 2/ and water vapour. Single-stage adsorption occurs under standard pressure at temperatures from -40 to +4/sup 0/C up to the point of CO penetration through the zeolite layer. Zeolite is of type A or X combined with Ca, Na, Ag, Cd, Co, Ni, Mn or a natural zeolite of the type klinoptilolite. Regeneration is achieved at constant temperature and pressure of 1-5x10/sup -1/ Torr or by heating to 120-600/sup 0/C.

  1. 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)

  2. Decommissioning of Phosphoric Acid Purification Facility, PT Petrokimia Gresik

    International Nuclear Information System (INIS)

    Zainus Salimin; Nanang TS; Zaid, Ach.; Chotimah; Karyono

    2008-01-01

    Decommissioning of phosporic acid purification facility was the administrative and technical actions taken to allow the removal of some or all of the regulatory control from that facility exploit the phosphoric acid containing uranium. The site location of facility was cleaned up as the clean previous site (green land) for another site project utilization. Decommissioning activities covers the draining of solution or solid powder of remaining process on the equipment, decontamination of site location and equipment wall, dismantling of equipment, decontamination of equipment after dismantling, and decontamination of concrete floor and wall. Uranium contaminated liquid waste and organic solution was treated by bio-oxidation process using bacteria. Remaining solid powder from process (28 drums), contaminated material and equipment after decontamination (60 drums of fire brick, 31 pieces of equipment cut, 2 drums of ashes, 10 drums of active sludge from bio-oxidation process) and concrete splinter of 10 drums of 200 l volume per drum are the radioactive waste that must be sent to Radioactive Waste Technology Centre for its treatment. The non contaminated material and equipment (908 ton) can be reused for reprocessing, some of non contaminated sludge (14.4 m 3 ) and all of non contaminated filtrate water (353 m 3 ) from bio-oxidation process with toxic matters qualification which comply to the its limit values are released on the effluent release drain system of the plant. Clearance level utilizing for filtering contaminated material or equipment was an activity concentration of 1 Bq/g, surface contamination of 1 Bq/cm 2 , effective dose on the 50 cm distance from surface of contaminated material of 0.5 μSv/h (BAPETEN Regulation Letter No. 1459A/P101/PIBN/2008). Limit values for toxic matter are pH 6-9, COD 100 ppm and BOD 50 ppm (Gov. Regulation of East Java No. 45 year of 2002). (author)

  3. 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.

  4. 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...

  5. Enhanced extraction and purification of plasmid DNA from escherichia coli by applying a hybrid magnetic nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.J. da; Chavez-Guajardo, A.E.; Medina-llamas, J.C.; Alcaraz-Espinoza, J.J.; Melo, C.P. de [Universidade Federal de Pernambuco (UFPE), PE (Brazil)

    2016-07-01

    Full text: Plasmid DNA (pDNA), a special kind of nucleic acid usually found in bacteria, is a small molecule physically distinct from chromosomal DNA that can replicate independently. This genetic material has been used in a wide set of biotechnological methodologies, such as genetic engineering, production of recombinant drugs and gene therapy, among others. In all these applications, the extraction and purification of pDNA appears as a crucial step. In this work, we describe the synthesis of a polyaniline and maghemite (PANI/?-Fe2O3) magnetic nanocomposite (MNC) and its use in a new Escherichia coli (E. coli) pDNA extraction and purification protocol. We have used transmission electron microscopy (TEM), UV-Vis spectroscopy, infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and magnetic measurements to characterize the MNC, which was synthesized through an emulsion polymerization method. The yield, purity and quality of the pDNA extracted by using our proposed MNC protocol were evaluated through UV-Vis, agarose gel electrophoreses and PCR techniques, respectively. After comparing our results to those obtained by use of a commercial kit (Promega Wizard Plus SV Minipreps), we suggest that the novel protocol here proposed appears as a competitive alternative methodology. Not only the purification step can be completed within only 10 min, but the high adsorption capacity of the MNC results in pDNA yields that are almost twice the best values obtained by using the commercial kit. Hence, this new MNC methodology can be of general interest and find widespread use in different types of biomedical applications. (author)

  6. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  7. Purification of alcohol obtained from molasses

    Energy Technology Data Exchange (ETDEWEB)

    Visnevskaya, G L; Egorov, A S; Sokol' skaya, E V

    1960-01-01

    A study of the composition of alcohol liquids on different plates of a fractionation column of indirect action during purification of alcohol obtained from normal and defective molasses, and from starch raw material, showed that there were two local strength minima in the lower part of the column and on the plates (adjacent and feed). Aldehydes behaved as a typical head impurity; a noticeable increase in their concentration occurred only on the highest plates in the fractionation column. In the zone of the column containing liquids of a strength of 86 to 94% alcohol by weight a sharply pronounced local maximum of ester accumulation were observed, provisionally designated as intermediate, whose presence is apparently one of the causes of the specific sharp taste of alcohol obtained from molasses. These esters hinder the obtaining of high-grade alcohols which are standard in respect to ester content and oxidizability test. Reduction with 0.05N KMnO/sub 4/ occurs most rapidly with alcohol liquids in the zone of ester accumulation; purification of alcohols obtained from grain and potato raw material resulted in no zones of ester accumulation in the column.

  8. Purification of radionuclides for nuclear medicine

    International Nuclear Information System (INIS)

    Horwitz, E.P.; Bond, A.H.

    2002-01-01

    Novel systems for the rapid separation of 67 Cu, 90 Y, 188 Re, 212 Bi, 213 Bi, and 223 Ra are described. To achieve the high levels of decontamination required of radionuclides used in radioimmunotherapy, we have utilised combinations of ion exchange (IX) and novel extraction chromatographic (EXC) resins. The objective of each separation system is to remove by many orders of magnitude the parent isotopes and to reduce the concentrations of stable, sometimes adventitious impurities, to low levels. The latter objective is particularly important to achieve a high degree of bonding of radionuclide onto a monoclonal antibody. The purification of 212 Bi (60.6 min half-life) furnishes a good example of the level of purity that we have achieved using tandem combinations of EXC and IX resins. Bismuth-212 was separated from its daughters, 212 Pb, 224 Ra, 228 Th and 232 U at the 50 mCi level. The resultant 212 Bi decayed to background in a few days indicative of high purity. Another example of extraordinary removal of parent nuclide from daughter nuclide and subsequent purification of daughter from stable elements is the preparation of 90 Y. Strontium-90 was removed from 90 Y by > 10 9 . The purified 90 Y uptake by monoclonal antibodies was close to 100%

  9. 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.

  10. Purification of bone morphogenetic protein-2 from refolding mixtures using mixed-mode membrane chromatography.

    Science.gov (United States)

    Gieseler, Gesa; Pepelanova, Iliyana; Stuckenberg, Lena; Villain, Louis; Nölle, Volker; Odenthal, Uwe; Beutel, Sascha; Rinas, Ursula; Scheper, Thomas

    2017-01-01

    In this study, we present the development of a process for the purification of recombinant human bone morphogenetic protein-2 (rhBMP-2) using mixed-mode membrane chromatography. RhBMP-2 was produced as inclusion bodies in Escherichia coli. In vitro refolding using rapid dilution was carried out according to a previously established protocol. Different membrane chromatography phases were analyzed for their ability to purify BMP-2. A membrane phase with salt-tolerant properties resulting from mixed-mode ligand chemistry was able to selectively purify BMP-2 dimer from refolding mixtures. No further purification or polishing steps were necessary and high product purity was obtained. The produced BMP-2 exhibited a biological activity of 7.4 × 10 5  U/mg, comparable to commercial preparations. Mixed-mode membrane chromatography can be a valuable tool for the direct purification of proteins from solutions with high-conductivity, for example refolding buffers. In addition, in this particular case, it allowed us to circumvent the use of heparin-affinity chromatography, thus allowing the design of an animal-component-free process.

  11. 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.

  12. Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Dolmatov, Valerii Yu [Federal State Unitary Enterprise Special Design-Technology Bureau (FSUE SDTB) ' ' Tekhnolog' ' at the St Petersburg State Institute of Technology (Technical University) (Russian Federation)

    2007-04-30

    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.

  13. 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.

  14. The purification, crystallization and preliminary X-ray diffraction analysis of dihydrodipicolinate synthase from Clostridium botulinum

    International Nuclear Information System (INIS)

    Dobson, Renwick C. J.; Atkinson, Sarah C.; Gorman, Michael A.; Newman, Janet M.; Parker, Michael W.; Perugini, Matthew A.

    2008-01-01

    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 2 2 1 2 symmetry. The unit-cell parameters were a = b = 92.9, c = 60.4 Å. The crystal volume per protein weight (V M ) was 2.07 Å 3 Da −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

  15. Sensitivity of certain bacteria to antibiotics and irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Harsojo,; Andini, L S; Siagian, E G; Lina, M R; Zuleiha, S [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

    1981-07-01

    An experiment has been conducted to find vegetative forms of certain bacteria in Indonesia which are resistant to irradiation, the resistance of which will be compared to that of known radioresistant bacteria micrococcus radiodurans. To inactivate the vegetative forms of resistant bacteria to irradiation high doses are needed, while for storage purposes lower doses change the physical and chemical properties of the stored commodity are preferred. For this purpose the bacteria were irradiated in aerobic condition with gamma radiation doses of 0.1, 0.2 and 0.3 kGy, or treated with antibiotics e.g. tetracycline HCl or chloramphenicol with concentrations of 0.1, 0.2 and 0.3 ..mu..g/ml respectively. The results indicated that doses of 0.2 kGy and 0.1 ..mu..g/ml reduced the ability of the bacteria for multiplication.

  16. 3D printing of bacteria into functional complex materials.

    Science.gov (United States)

    Schaffner, Manuel; Rühs, Patrick A; Coulter, Fergal; Kilcher, Samuel; Studart, André R

    2017-12-01

    Despite recent advances to control the spatial composition and dynamic functionalities of bacteria embedded in materials, bacterial localization into complex three-dimensional (3D) geometries remains a major challenge. We demonstrate a 3D printing approach to create bacteria-derived functional materials by combining the natural diverse metabolism of bacteria with the shape design freedom of additive manufacturing. To achieve this, we embedded bacteria in a biocompatible and functionalized 3D printing ink and printed two types of "living materials" capable of degrading pollutants and of producing medically relevant bacterial cellulose. With this versatile bacteria-printing platform, complex materials displaying spatially specific compositions, geometry, and properties not accessed by standard technologies can be assembled from bottom up for new biotechnological and biomedical applications.

  17. A porous silicon optical microcavity for sensitive bacteria detection

    International Nuclear Information System (INIS)

    Li Sha; Huang Jianfeng; Cai Lintao

    2011-01-01

    A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak (∼10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml -1 at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml -1 . The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

  18. A porous silicon optical microcavity for sensitive bacteria detection

    Science.gov (United States)

    Li, Sha; Huang, Jianfeng; Cai, Lintao

    2011-10-01

    A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak (~10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml - 1 at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml - 1. The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

  19. A porous silicon optical microcavity for sensitive bacteria detection

    Energy Technology Data Exchange (ETDEWEB)

    Li Sha; Huang Jianfeng; Cai Lintao, E-mail: lt.cai@siat.ac.cn [CAS Key Lab of Health Informatics, Shenzhen Key Laboratory of Cancer Nanotechnology, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055 (China)

    2011-10-21

    A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak ({approx}10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml{sup -1} at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml{sup -1}. The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

  20. Thermophilic, lignocellulolytic bacteria for ethanol production: current state and perspectives

    DEFF Research Database (Denmark)

    Chang, Tinghong; Yao, Shuo

    2011-01-01

    of cellulolytic and saccharolytic thermophilic bacteria for lignocellulosic ethanol production because of their unique properties. First of all, thermophilic bacteria possess unique cellulolytic and hemicellulolytic systems and are considered as potential sources of highly active and thermostable enzymes...... for efficient biomass hydrolysis. Secondly, thermophilic bacteria ferment a broad range of carbohydrates into ethanol, and some of them display potential for ethanologenic fermentation at high yield. Thirdly, the establishment of the genetic tools for thermophilic bacteria has allowed metabolic engineering......, in particular with emphasis on improving ethanol yield, and this facilitates their employment for ethanol production. Finally, different processes for second-generation ethanol production based on thermophilic bacteria have been proposed with the aim to achieve cost-competitive processes. However, thermophilic...

  1. Purification and characterization of a new bacteriocin active against Campylobacter produced by Lactobacillus salivarius SMXD51.

    Science.gov (United States)

    Messaoudi, Soumaya; Kergourlay, Gilles; Dalgalarrondo, Michèle; Choiset, Yvan; Ferchichi, Mounir; Prévost, Hervé; Pilet, Marie-France; Chobert, Jean-Marc; Manai, Mohamed; Dousset, Xavier

    2012-10-01

    Strain SMXD51, isolated from chicken ceca and identified as Lactobacillus salivarius, produced a component that inhibits the growth of Gram-positive and Gram-negative bacteria and especially Campylobacter jejuni. The active peptide from the cell-free supernatant of Lb. salivarius SMXD51 was purified in three steps: (i) precipitation with 80% saturated ammonium sulfate, (ii) elution on a reversed phase SPE UPTI-CLEAN cartridge using different concentrations of acetonitrile, (iii) final purification by reversed phase HPLC on a C(18) column. The mode of action of this peptide of 5383.2 Da was identified as bactericidal, and its amino acid composition was established. This new bacteriocin SMXD51 appears potentially very useful to reduce Campylobacter in poultry prior to processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Effect of water purification process in radioactive content: analysis on small scale purification plants

    International Nuclear Information System (INIS)

    Lopez del Rio, H.; Quiroga S, J. C.; Davila R, J. I.; Mireles G, F.

    2009-10-01

    Water from small scale purification plants is a low cost alternative for consumers in comparison to the bottled commercial presentations. Because of its low cost per liter, the consumption of this product has increased in recent years, stimulating in turn the installation of purification systems for these small businesses. The purpose of this study was to estimate the efficiency of small scale purification systems located in the cities of Zacatecas and Guadalupe, Zacatecas, to reduce the radioactive content of water. It was measured the total alpha and beta activity in water samples of entry and exit to process, through the liquid scintillation technique. In general it was observed that the process is more efficient in removing alpha that beta activity. The fraction of total alpha activity removed varied between 27 and 100%, while between 0 and 77% of the total beta activity was removed by the analyzed plants. In all cases, the total radioactivity level was lower than the maximum permissible value settled by the official mexican standard for drinking water. (Author)

  3. Physiological characteristics of bacteria isolated from water brines within permafrost

    Science.gov (United States)

    Shcherbakova, V.; Rivkina, E.; Laurinavichuis, K.; Pecheritsina, S.; Gilichinsky, D.

    2004-01-01

    In the Arctic there are lenses of overcooled water brines (cryopegs) sandwiched within permafrost marine sediments 100 120 thousand years old. We have investigated the physiological properties of the pure cultures of anaerobic Clostridium sp. strain 14D1 and two strains of aerobic bacteria Psychrobacter sp. isolated from these cryopegs. The structural and physiological characteristics of new bacteria from water brines have shown their ability to survive and develop under harsh conditions, such as subzero temperatures and high salinity.

  4. Functional amyloids in bacteria.

    Science.gov (United States)

    Romero, Diego; Kolter, Roberto

    2014-06-01

    The term amyloidosis is used to refer to a family of pathologies altering the homeostasis of human organs. Despite having a name that alludes to starch content, the amyloid accumulations are made up of proteins that polymerize as long and rigid fibers. Amyloid proteins vary widely with respect to their amino acid sequences but they share similarities in their quaternary structure; the amyloid fibers are enriched in β-sheets arranged perpendicular to the axis of the fiber. This structural feature provides great robustness, remarkable stability, and insolubility. In addition, amyloid proteins specifically stain with certain dyes such as Congo red and thioflavin-T. The aggregation into amyloid fibers, however, it is not restricted to pathogenic processes, rather it seems to be widely distributed among proteins and polypeptides. Amyloid fibers are present in insects, fungi and bacteria, and they are important in maintaining the homeostasis of the organism. Such findings have motivated the use of the term "functional amyloid" to differentiate these amyloid proteins from their toxic siblings. This review focuses on systems that have evolved in bacteria that control the expression and assembly of amyloid proteins on cell surfaces, such that the robustness of amyloid proteins are used towards a beneficial end. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  5. Development of composite metallic membranes for hydrogen purification

    International Nuclear Information System (INIS)

    Gaillard, F.

    2003-12-01

    Fuel cells are able to convert chemical energy into electric power. There are different types of cells; the best for automotive applications are Proton Exchange Membrane Fuel Cells. But, these systems need hydrogen of high purity. However, fuel reforming generates a mixture of gases, from which hydrogen has to be extracted before supplying the electrochemical cell. The best way for the purification of hydrogen is the membrane separation technology. Palladium is selectively permeable to hydrogen and this is the reason why this metal is largely used for the membrane development. This work deals with the development of hydrogen-selective membranes by deposition of a thin film of palladium onto a porous mechanical support. For this, we have used the electroless plating technique: a palladium salt and a reducing agent are mixed and the deposition takes place onto the catalytic surface of the substrate. After bibliographic investigations, experimental studies have been performed first with a dense metallic substrate in order to better understand the different parameters controlling the deposition. First of all, potentiometric measurements have been carried out to follow the electrochemical reactions in the bath. Then, kinetic measurements of the coating thickness have been recorded to understand the effect of the bath conditions on the yield and the adhesion of the film. Finally, the electroless plating method has been applied to deposit palladium membranes onto porous stainless steel substrates. After optimisation, the resulting membranes were tested for their hydrogen permeation properties. (author)

  6. Design and optimisation of purification procedure for biodiesel washing

    Directory of Open Access Journals (Sweden)

    S.B. Glišić

    2009-09-01

    Full Text Available Almost complete methanolysis of triglycerides is usually not enough to fulfil the strict standards of biodiesel quality. A key step in this process is neutralization of alkali (catalyst followed by the washing procedure necessary for removing different impurities such as traces of catalyst and methanol and removal of soaps and glycerol from esters phase. The washing with hot water is still widely used in many industrial units for the biodiesel production. In this study, different procedures of biodiesel washing using hot water were investigated. The orto-phosphoric acid was suggested as the best compound for alkali catalyst (sodium hydroxide neutralization. The main goal of the performed analysis was to minimize the water usage in the washing-neutralization step during the biodiesel production. Such solution would make the process of biodiesel synthesis more economical taking into account the decrease of energy consumed for evaporation of water during the final product purification, as well as more acceptable procedure related to the impact on environment (minimal waste water release. Results of the performed simulation of the washing process supported by original experimental data suggested that neutralization after the optimized washing process of the methyl ester layer could be the best solution. The proposed washing procedure significantly decreases the amount of waste water giving at the same time the desired purity of final products (biodiesel and glycerol. The simulation of the process was performed using ASPEN plus software supported by ELCANTREL and UNIQUAC procedure of required properties calculation

  7. Purification, Characterization and Application of Polygalacturonase from Aspergillus niger CSTRF

    Directory of Open Access Journals (Sweden)

    Arotupin Daniel Juwon

    2012-09-01

    Full Text Available Aims: The research was carried out to study the purification, characterization and application of polygalacturonase fromAspergillus niger CSTRF.Methodology and Results: The polygalacturonase (PG from the fungus was purified by ammonium sulphate precipitation and dialysed. The resulting fraction of the enzyme was further separated by molecular exclusion and ion exchange chromatography. The enzyme was purified 28.19 fold with a yield of approximately 69 % following purificationwith SP C-50. It has a relative molecular weight of 79,430 daltons and markedly influenced by temperature, pH and substrate concentrations of reactions with optimum activity at 35 °C, pH 4.0 and 8 mg/mL respectively. The PG was heat stable over a broad range of temperatures. Line weaver-Burk plot for the apparent hydrolysis of pectin showed approximately Km value of 2.7 mg/mL. The activity of the enzyme was enhanced by Na+, Ca2+, Mg2+ and Zn2+, while EDTA, PbCl2, HgCl2 and IAA were inhibitory. The ability of the purified enzyme to clarify fruit juice was also investigated.Conclusion, significance and impact of the study: This study revealed that polygalacturonase possesses properties for clarification of fruit juice and by extension bioprocessing applications.

  8. Submersible purification system for radioactive water

    Science.gov (United States)

    Abbott, Michael L.; Lewis, Donald R.

    1989-01-01

    A portable, submersible water purification system for use in a pool of water containing radioactive contamination includes a prefilter for filtering particulates from the water. A resin bed is then provided for removal of remaining dissolved, particulate, organic, and colloidal impurities from the prefiltered water. A sterilizer then sterilizes the water. The prefilter and resin bed are suitably contained and are submerged in the pool. The sterilizer is water tight and located at the surface of the pool. The water is circulated from the pool through the prefilter, resin bed, and sterilizer by suitable pump or the like. In the preferred embodiment, the resin bed is contained within a tank which stands on the bottom of the pool and to which a base mounting the prefilter and pump is attached. An inlet for the pump is provided adjacent the bottom of the pool, while the sterilizer and outlet for the system is located adjacent the top of the pool.

  9. Purification of tritium-free water

    International Nuclear Information System (INIS)

    Hussain, S.D.

    1982-10-01

    Ground water which has been out of contact with the atmosphere for a long time as compared to the half life of tritium (12.43 years) does not contain any measureable amount of tritium. Such water is called tritium-free water. It may contain dissolved and suspended impurities and has to be purified before it can be used for the preparation of blanks and standards required in the routine measurement of low level tritium in water samples. The purification of tritium-free water by distillation in a closed system has been described. The quality of processed tritium-free water was precisely checked at International Atomic Energy Agency (IAEA) Vienna and found satisfactory. (authors)

  10. Radioligand purification prior to routine receptor assays

    International Nuclear Information System (INIS)

    Le Goff, J.-M.; Berthois, Y.; Martin, P.-M.

    1988-01-01

    The need to repurify the commercially available radioligands [ 3 H]estradiol and [ 3 H]testosterone before use in routine assays was investigated. Storage of these products for 2 months after delivery led to appreciable degradation of [ 3 H]estradiol compared to [ 3 H]testosterone. Unexpectedly, TLC and even HPLC procedures were ineffective in completely restoring the purity of [ 3 H]-estradiol and the unremoved polar products induced important variations in our estrogen receptor assays. An increase in non-specific binding and a concomitant decrease in total binding were observed resulting in an underestimation of specific binding sites and of the affinity constant. In some cases Scatchard analysis was not possible. The authors therefore strongly recommend the repurification of low-stability radioligands and propose an economic time-saving procedure for the purification of [ 3 H]estradiol by solvent differential partition which requires no high-cost investment in apparatus. (author)

  11. Purification of biomaterials by phase partitioning

    Science.gov (United States)

    Harris, J. M.

    1984-01-01

    A technique which is particularly suited to microgravity environments and which is potentially more powerful than electrophoresis is phase partitioning. Phase partitioning is purification by partitioning between the two immiscible aqueous layers formed by solution of the polymers poly(ethylene glycol) and dextran in water. This technique proved to be very useful for separations in one-g but is limited for cells because the cells are more dense than the phase solutions thus tend to sediment to the bottom of the container before reaching equilibrium with the preferred phase. There are three phases to work in this area: synthesis of new polymers for affinity phase partitioning; development of automated apparatus for ground-based separations; and design of apparatus for performing simple phase partitioning space experiments, including examination of mechanisms for separating phases in the absence of gravity.

  12. Water purification using solar radiation in Nigeria

    International Nuclear Information System (INIS)

    Udounwa, A.E.; Osuji, R.U.

    2005-12-01

    In developing countries, lack of safe and reliable drinking water constitutes a major problem. Contaminated water is the major cause of most water borne diseases like diarrhoea. Disinfection of water is accomplished by a number of different physical - chemical treatments including boiling, application of chlorine and filtration techniques. Solar energy, which is universally available, can also be used effectively in this process, that is, to deactivate the micro-organisms present in this contaminated water thereby improving its microbiological quality. This treatment process is called solar water disinfection. This paper therefore appraises the extent to which research work has been done as regards purification of water using solar radiation in Nigeria vis-a-vis outside the country. It is hoped that it will serve as a wake-up-call for Nigerians especially those in remote areas with no treated pipe borne water supply. The problems and prospects of this technology as well as the policy implications are presented. (author)

  13. Purification of equine Gc-globulin

    DEFF Research Database (Denmark)

    Houen, Gunnar; Pihl, Tina Holberg; Andersen, Pia Haubro

    Objectives With the aim of producing antibodies for an equine Group specific component (Gc)-globulin assay, the protein was purified from normal equine plasma. Methods Equine Gc-globulin was purified from healthy horse plasma using ion exchange chromatography (Q-Sepharose, CM......-Sepharose) and preparative PAGE. Results Equine Gc-globulin has successfully been purified from healthy horse plasma and rabbits and mice are being immunized to produce specific antibodies. Conclusions Purification of equine Gc-globulin and the production of specific antibodies will make it possible to develop an assay...... to be a sensitive marker of acute tissue injury and fatal outcome in humans. Patients with a low plasma concentration of Gc-globulin due to severe tissue injury might potentially benefit from infusions with purified Gc-globulin [1]. With an equine Gc-globulin assay, future studies will investigate the concentration...

  14. (Hyper)thermophilic enzymes: production and purification.

    Science.gov (United States)

    Falcicchio, Pierpaolo; Levisson, Mark; Kengen, Servé W M; Koutsopoulos, Sotirios

    2014-01-01

    The discovery of thermophilic and hyperthermophilic microorganisms, thriving at environmental temperatures near or above 100 °C, has revolutionized our ideas about the upper temperature limit at which life can exist. The characterization of (hyper)thermostable proteins has broadened our understanding and presented new opportunities for solving one of the most challenging problems in biophysics: how is structural stability and biological function maintained at high temperatures where "normal" proteins undergo dramatic structural changes? In our laboratory we have purified and studied many thermostable and hyperthermostable proteins in an attempt to determine the molecular basis of heat stability. Here, we present methods to express such proteins and enzymes in E. coli and provide a general protocol for overproduction and purification. The ability to produce enzymes that retain their stability and activity at elevated temperatures creates exciting opportunities for a wide range of biocatalytic applications.

  15. Vitreous membranes used in the biogas purification

    International Nuclear Information System (INIS)

    Ortega Viera, L.; Rodriguez Munoz, S.; Fernandez Santana, E.; Martines Ramirez, Y.; Crespo Artigas, A.; Viera Gallardo, Y.

    2016-01-01

    In the present work 10 vitreous membranes with different masses of zinc oxide (ZnO(s)) and particle diameters charcoal (DPC) are used in the purification of biogas. The porosity and tortuosity of the membranes is obtained, showing the variation with respect to the composition thereof. From these structural features specific flow of H 2 S(g) is obtained which is transferred using the Fick's diffusion equation in the membranes and its value increases with increasing mass of ZnO(s). By X-ray diffraction membrane made with 3.16 g of ZnO(s) forming zinc sulfide it is shown, so we can say that the removal of H 2 S(g) occurs by a process of absorption with chemical reaction in the membranes. (Author)

  16. Augmenting static and dynamic mechanical strength of carbon nanotube/epoxy soft nanocomposites via modulation of purification and functionalization routes.

    Science.gov (United States)

    Billing, Beant Kaur; Dhar, Purbarun; Singh, Narinder; Agnihotri, Prabhat K

    2018-01-03

    A detailed experimental investigation was carried out to establish the relationship between CNT purification and functionalization routes and the average response of CNT/epoxy nanocomposites under static and dynamic loading. It was shown that the relative improvement in the mechanical properties of the epoxy matrix due to the addition of CNTs depends on the choice of purification and functionalization steps. A better dispersion of CNTs was recorded for the functionalized CNTs as compared to the oxidized and CVD grown CNTs. Moreover, tensile, 3-point bending and nanoDMA testing performed on nanocomposites processed with CVD-grown, oxidized and functionalized CNTs revealed that COOH functionalization after the oxidation of CNTs at 350 °C is the optimized processing route to harness the excellent properties of CNTs in CNT/epoxy nanocomposites.

  17. Radiation purification of water from cyanides

    International Nuclear Information System (INIS)

    Piskarev, I.M.; Rylova, A.E.; Sevast'yanov, A.I.

    1994-01-01

    Attempts at performing the process of radiation purification of water from cyanides have been described in the literature and were briefly reviewed earlier. Sodium cyanide solutions were examined in a concentration range from 26 mg/l to 80 g/l. The data given in various publications often disagree. Radiation yields of cyanide decay vary from 0.48 to 28 molecule/100 eV for equal dose rates, according to the data presented by various authors, and the maximum yield of 1200 was attained at a low dose rate (0.18 kGy/h) in a neutral solution. Chain decomposition of cyanides was observed in some studies, but not in others; the acidity of the solution examined was not necessarily reported. It was specified that complete decomposition of cyanides occurs; however, no detection limits for the analytical procedures of cyanide determination were reported. The authors performed experiments on the purification of actual industrial waste waters (solution and slurry), which were preliminarily preserved with sodium hydroxide (pH 9; the cyanide content was 90 mg/1). Solutions in dishes 40 mm in diameter and 20 or 40 mm in height were exposed to X-rays with a maximum energy of bremsstrahlung spectrum of 70 keV. Volumes of the solutions were 20 and 40 ml. With consideration for angular divergence and beam attenuation by solution, the average absorbed-dose rates were 1.5 and 3.1 kGy/h for dishes of V equal to 40 and 20 ml, respectively. Measurements of the absorbed dose were made with a ferrosulfate dosimeter

  18. Screening and characterization of phosphate solubilizing bacteria from isolate of thermophilic bacteria

    Science.gov (United States)

    Yulianti, Evy; Rakhmawati, Anna

    2017-08-01

    The aims of this study were to select bacteria that has the ability to dissolve phosphate from thermophilic bacteria isolates after the Merapi eruption. Five isolates of selected bacteria was characterized and continued with identification. Selection was done by using a pikovskaya selective medium. Bacterial isolates were grown in selective medium and incubated for 48 hours at temperature of 55 ° C. Characterization was done by looking at the cell and colony morphology, physiological and biochemical properties. Identification was done with the Profile Matching method based on the reference genus Oscillospira traced through Bergey's Manual of Determinative Bacteriology. Dendogram was created based on similarity index SSM. The results showed there were 14 isolates of bacteria that were able to dissolve phosphate indicated by a clear zone surrounding the bacterial colony on selective media. Five isolates were selected with the largest clear zone. Isolates D79, D92, D110a, D135 and D75 have different characters. The result of phenotypic characters identification with Genus Oscillospira profile has a percentage of 100% similarity to isolate D92 and D110a; 92.31% for isolates D79, and 84.6% for isolates D75 and D135. Dendogram generated from average linkage algorithm / UPGMA using the Simple Matching Coefficient (SSM) algorithms showed, isolate thermophilic bacteria D75 and D135 are combined together to form cluster 1. D110a and D92 form a sub cluster A. Sub cluster A and D79 form cluster 2

  19. Fish skin bacteria: Colonial and cellular hydrophobicity.

    Science.gov (United States)

    Sar, N; Rosenberg, E

    1987-05-01

    Bacteria were desorbed from the skin of healthy, fast-swimming fish by several procedures, including brief exposure to sonic oscillation and treatment with nontoxic surface active agents. The surface properties of these bacteria were studied by measuring their adhesion to hexadecane, as well as by a newly developed, simple method for studying the hydrophobicity of bacterial lawns. This method, referred to as the "Direction of Spreading" (DOS) method, consists of recording the direction to which a water drop spreads when introduced at the border between bacterial lawns and other surfaces. Of the 13 fish skin isolates examined, two strains were as hydrophobic as polystyrene by the DOS method. Suspended cells of one of these strains adhered strongly to hexadecane (84%), whereas cells of the other strain adhered poorly (13%). Another strain which was almost as hydrophobic as polystyrene by the DOS method did not adhere to hexadecane at all. Similarly, lawns of three other strains were more hydrophobic than glass by the DOS method, but cell suspensions prepared from these colonies showed little or no adhesion to hexadecane. The high colonial but relatively low cellular hydrophobicity could be due to a hydrophobic slime that is removed during the suspension and washing procedures. The possibility that specific bacteria assist in fish locomotion by changing the surface properties of the fish skin and by producing drag-reducing polymers is discussed.

  20. Expression, purification and insights into structure and folding of the ADAM22 pro domain

    DEFF Research Database (Denmark)

    Sørensen, Hans Peter; Jacobsen, Jonas; Nielbo, Steen

    2008-01-01

    . To understand the functions of human ADAM pro domains and to determine three-dimensional structures, we have screened promising targets for expression and purification properties when using Escherichia coli as the host. The pro domain of ADAM22 (ADAM22-P) expressed in E. coli was folded, as determined by CD...... and NMR spectroscopy. An ADAM22-P fragment encoding residues 26-199 could be expressed in high amounts, remained soluble above 1 mM, and was suitable for structural studies by NMR spectroscopy. CD spectroscopy and predictions suggest that the secondary structure in ADAM22-P consists of beta...

  1. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  2. INDUSTRIAL GAS PURIFICATION USE OF BIOFILTERS

    Directory of Open Access Journals (Sweden)

    Irina Ramona PECINGINĂ

    2012-05-01

    Full Text Available Biological filtration systems is one of the current alternatives to remove residual volatile components of the air through biological means, without affecting the natural environment. Biofilters have a technology that uses microorganisms (bacteria to treat emissions, in a secure economic and environmental quality. Biofilters consist of porous filters, which is distributed flue gas stream

  3. Purification and characterization of phenoloxidase from immunized ...

    African Journals Online (AJOL)

    The present study has been conducted to purify and characterize the PO from the haemolymph of desert locust, Schistocerca gregaria (Forskal) following activation of immune system by invasion of bacteria, Bacillus thuringiensis kurstaki (Bt). PO is purified by a combination of ammonium sulfate precipitation, blue sepharose ...

  4. Two-step purification of His-tagged Nef protein in native condition using heparin and immobilized metal ion affinity chromatographies.

    Science.gov (United States)

    Finzi, Andrés; Cloutier, Jonathan; Cohen, Eric A

    2003-07-01

    The Nef protein encoded by human immunodeficiency virus type 1 (HIV-1) has been shown to be an important factor of progression of viral growth and pathogenesis in both in vitro and in vivo. The lack of a simple procedure to purify Nef in its native conformation has limited molecular studies on Nef function. A two-step procedure that includes heparin and immobilized metal ion affinity chromatographies (IMACs) was developed to purify His-tagged Nef (His(6)-Nef) expressed in bacteria in native condition. During the elaboration of this purification procedure, we identified two closely SDS-PAGE-migrating contaminating bacterial proteins, SlyD and GCHI, that co-eluted with His(6)-Nef in IMAC in denaturing condition and developed purification steps to eliminate these contaminants in native condition. Overall, this study describes a protocol that allows rapid purification of His(6)-Nef protein expressed in bacteria in native condition and that removes metal affinity resin-binding bacterial proteins that can contaminate recombinant His-tagged protein preparation.

  5. Radiation-resistant asporogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Yano, K [Tokyo Univ. (Japan). Faculty of Agriculture

    1975-09-01

    This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned.

  6. Radiation-resistant asporogenic bacteria

    International Nuclear Information System (INIS)

    Yano, Keiji

    1975-01-01

    This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned. (Tsukamoto, Y.)

  7. The interaction of bacteria and metal surfaces

    International Nuclear Information System (INIS)

    Mansfeld, Florian

    2007-01-01

    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E corr became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V)-current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions

  8. The interaction of bacteria and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mansfeld, Florian [Corrosion and Environmental Effects Laboratory (CEEL), The Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-0241 (United States)

    2007-10-10

    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E{sub corr} became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V) - current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions. (author)

  9. Production and purification of polyclonal anti-hamster ...

    African Journals Online (AJOL)

    . ... IgG showed high titer and high specificity in the designed ELISA. Purified antibody and its conjugation with HRP are used in research and diagnosis of hamster disease. Key words: Production, purification, hamster immunoglobulins.

  10. Microbiological and technical aspects of anaerobic waste water purification

    International Nuclear Information System (INIS)

    Aivasidis, A.

    1994-01-01

    Anaerobic waste water purification is likely to be another example of how innovations can result from the joint use of biological and technical concepts. No matter how far the optimization of oxygen input with aerobic waste water purification advances it will still be the less a real competitor for anaerobic techniques the more polluted the waste water is. The principle of carrier fixation to avoid their washing out, too, has often been observed in nature with sessile microorganisms. With highly polluted water, anaerobic purification does not only work at no expenditure of energy but it can also make excess energy available for use in other processes. Another important argument for anaerobic methods of waste water purification is probably the clearly reduced production of excess sludge. (orig.) [de

  11. Generation and purification of human stem cell-derived cardiomyocytes

    NARCIS (Netherlands)

    Schwach, Verena; Passier, Robert

    2016-01-01

    © 2016 International Society of Differentiation Efficient and reproducible generation and purification of human stem cell-derived cardiomyocytes (CMs) is crucial for regenerative medicine, disease modeling, drug screening and study of developmental events during cardiac specification. Established

  12. Extraction and Purification of Flavonoids from Radix Puerariae

    African Journals Online (AJOL)

    and preparations are now on sale. ... significant for optimization of extraction, resin selection and ... and flavonoids as indexes, optimize the proper density. ..... system. Sep Purif Technol. 2008; 62: 590-595. 12. Chen JH, Liau BC, Jong TT.

  13. Radiation-adsorption purification of effluents containing pesticides

    International Nuclear Information System (INIS)

    Brusentseva, S.A.; Shubin, V.N.; Nikonorova, G.K.; Zorin, D.M.; Sosnovskaya, A.A.; Petryaev, E.P.; Vlasova, V.I.; Edimicheva, I.P.; Subbotina, N.N.; Belorusskij Gosudarstvennyj Univ., Minsk)

    1986-01-01

    The radiation-adsorption purification is one of the new direction in the radiation purification of natural wastes and effluents containing pesticides. This method combines the conventional adsorption purification with radiation treatment of the sorbent, and the result the protection time of the sorbent increases due to the radiation regeneration of carbon. In present work the method was used for purification of effluents from pesticides, such as 4,4'Dichlorodiphenyltrichloroethane /DDT/, 1,2,3,4,5,6-hexachlorocyclohexane /HCCH/, dimethyl 2,2-dichlorovinylphosphate /DDVF/ and petroleum products (a mixture of kerosene and xylene in ratio 7:1). Such effluents are formed at factories producing an insecticide aerosol 'Prime-71'. Three investigations were carried out on model with a solution similar composition to industrial effluents. (author)

  14. The technology of large-scale pharmaceutical plasmid purification ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... DNA vaccine, the cost of purification must be decreased. Although commonly .... Three mice were killed every 4 days interval. Tissues of heart, liver, .... Now, methods such as chromatography had good prospects in plasmid ...

  15. Comparative study of methods for extraction and purification of ...

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... and or enzymatic lysis for direct or indirect extraction of. DNA followed by ... strength wastewater sludge in order to determine the best. DNA extraction protocol ... Ammonium acetate purification method was used to remove the.

  16. Vegetation characteristics and water purification by artificial floating ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... INTRODUCTION. Environmental pollution poses a grave menace to the ... major functions; 1) water purification, 2) providing habitats for certain animals ... areas. The aims were to; 1) select certain emerging plants effective at ...

  17. The Partial Purification and Characterization of Trypsin From the ...

    African Journals Online (AJOL)

    VESTEL

    fractionation, dialysis and Sephadex G-75 gel filtration. The purification fold and yield were 6.23 and. 4.49%, respectively. .... It was subjected to water wash and digestive tracts were .... sulphate precipitation was a simple method and generally.

  18. Acoustofluidic bacteria separation

    International Nuclear Information System (INIS)

    Li, Sixing; Huang, Tony Jun; Ma, Fen; Zeng, Xiangqun; Bachman, Hunter; Cameron, Craig E

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device. (paper)

  19. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  20. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  1. A new helium gas recovery and purification system

    International Nuclear Information System (INIS)

    Yamamotot, T.; Suzuki, H.; Ishii, J.; Hamana, I.; Hayashi, S.; Mizutani, S.; Sanjo, S.

    1974-01-01

    A helium gas recovery and purification system, based on the principle of gas permeation through a membrane, is described. The system can be used for the purification of helium gas containing air as a contaminant. The apparatus, operating at ambient temperature does not need constant attention, the recovery ratio of helium gas is satisfactory and running costs are low. Gases other than helium can be processed with the apparatus. (U.K.)

  2. Health physics system scheme for the uranium purification plant

    International Nuclear Information System (INIS)

    Meyer, M.; Oliveira, E.C.; Sordi, G.A.A.; Abrao, A.

    1976-01-01

    After describing the two uranium purification processes used in the Chemical Engineerring Division of the Instituto de Energia Atomica, it is examined the possible hazards and methods to control or eliminate them. Since these purification process present several stages, in each one of them it is evaluated the hazards and tried to give adequate solutions to protect both, personnel and installations, from the potential radiation hazards

  3. Specialists' meeting on fast reactor cover gas purification

    International Nuclear Information System (INIS)

    1987-01-01

    The tentative agenda was adopted by the participants without comment and was followed throughout the meeting. The following topics were discussed at the subsequent sessions of the meeting on 'Fast Reactor Cover Gas Purification': National Position Papers; Impurities: Sources and Measurement; Cover Gas Purification Techniques; Sodium Aerosol Trapping; Radiological Considerations. Based on the papers presented and the discussions following, session summaries and conclusions were prepared and are included in this report

  4. Specialists' meeting on fast reactor cover gas purification

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-07-01

    The tentative agenda was adopted by the participants without comment and was followed throughout the meeting. The following topics were discussed at the subsequent sessions of the meeting on 'Fast Reactor Cover Gas Purification': National Position Papers; Impurities: Sources and Measurement; Cover Gas Purification Techniques; Sodium Aerosol Trapping; Radiological Considerations. Based on the papers presented and the discussions following, session summaries and conclusions were prepared and are included in this report.

  5. Purification of human platelet-derived growth factor

    International Nuclear Information System (INIS)

    Raines, E.W.; Ross, R.

    1985-01-01

    The paper describes a method for purification of human platelet-derived growth factor (PDGF) from outdated platelet-rich plasma (PRP) using commonly available laboratory reagents and yielding a mitogen purified 800,000-fold over the starting material. [ 3 H]thymidine incorporation into DNA of cultured cells responsive to PDGF represents the most readily available method to follow its purification and define the biological activity of a purified preparation. Other assays to quantitate PDGF include radioreceptor assay and radioimmunoassay

  6. Improving the large scale purification of the HIV microbicide, griffithsin.

    Science.gov (United States)

    Fuqua, Joshua L; Wanga, Valentine; Palmer, Kenneth E

    2015-02-22

    Griffithsin is a broad spectrum antiviral lectin that inhibits viral entry and maturation processes through binding clusters of oligomannose glycans on viral envelope glycoproteins. An efficient, scaleable manufacturing process for griffithsin active pharmaceutical ingredient (API) is essential for particularly cost-sensitive products such as griffithsin -based topical microbicides for HIV-1 prevention in resource poor settings. Our previously published purification method used ceramic filtration followed by two chromatography steps, resulting in a protein recovery of 30%. Our objective was to develop a scalable purification method for griffithsin expressed in Nicotiana benthamiana plants that would increase yield, reduce production costs, and simplify manufacturing techniques. Considering the future need to transfer griffithsin manufacturing technology to resource poor areas, we chose to focus modifying the purification process, paying particular attention to introducing simple, low-cost, and scalable procedures such as use of temperature, pH, ion concentration, and filtration to enhance product recovery. We achieved >99% pure griffithsin API by generating the initial green juice extract in pH 4 buffer, heating the extract to 55°C, incubating overnight with a bentonite MgCl2 mixture, and final purification with Capto™ multimodal chromatography. Griffithsin extracted with this protocol maintains activity comparable to griffithsin purified by the previously published method and we are able to recover a substantially higher yield: 88 ± 5% of griffithsin from the initial extract. The method was scaled to produce gram quantities of griffithsin with high yields, low endotoxin levels, and low purification costs maintained. The methodology developed to purify griffithsin introduces and develops multiple tools for purification of recombinant proteins from plants at an industrial scale. These tools allow for robust cost-effective production and purification of

  7. Re-purification of labelled ferritin antigen with HPLC

    International Nuclear Information System (INIS)

    Zhang Haoyi; Jin Lichun

    2002-01-01

    Objective: To improve the quality of long-term stored labelled ferritin antigen with HPLC. Methods: The antigen was analyzed and purified with HPLC and again analyzed with RIA afterwards. Results: Ferritin antigen underwent significant polymerization after long-term (aggregation) storage. After re-purification with HPLC, its immuno-activity and labelled specific radioactivity were both significantly improved. Conclusion: Quality of stored ferritin RIA kit could be greatly improved after re-purification with HPLC

  8. Economic Methods of Ginger Protease'sextraction and Purification

    Science.gov (United States)

    Qiao, Yuanyuan; Tong, Junfeng; Wei, Siqing; Du, Xinyong; Tang, Xiaozhen

    This article reports the ginger protease extraction and purification methods from fresh ginger rhizome. As to ginger protease extraction, we adapt the steps of organic solvent dissolving, ammonium sulfate depositing and freeze-drying, and this method can attain crude enzyme powder 0.6% weight of fresh ginger rhizome. The purification part in this study includes two steps: cellulose ion exchange (DEAE-52) and SP-Sephadex 50 chromatography, which can purify crude ginger protease through ion and molecular weight differences respectively.

  9. Purification and Characterization of Lipase from Aspergillus flavus ...

    African Journals Online (AJOL)

    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. The optimal ...

  10. The entanglement purification for entangled multi-particle states

    CERN Document Server

    Ye, Liu; Guo Guang Can

    2002-01-01

    We present two purification schemes for nonmaximally entangled states. We first show that two parties, Alice and Bob, start with shared less-entangled three-particle states to probabilistically produce a three-particle Greenberger-Horne-Zeilinger state by Bell state measurements and positive operator valued measure (POVM) or a unitary transformation. Then, by a straightforward generalization of the schemes, the purification of a multi-particle entangled state can be realized. 25 Refs. --- 35 --- AN

  11. Affinity chromatography: A versatile technique for antibody purification.

    Science.gov (United States)

    Arora, Sushrut; Saxena, Vikas; Ayyar, B Vijayalakshmi

    2017-03-01

    Antibodies continue to be extremely utilized entities in myriad applications including basic research, imaging, targeted delivery, chromatography, diagnostics, and therapeutics. At production stage, antibodies are generally present in complex matrices and most of their intended applications necessitate purification. Antibody purification has always been a major bottleneck in downstream processing of antibodies, due to the need of high quality products and associated high costs. Over the years, extensive research has focused on finding better purification methodologies to overcome this holdup. Among a plethora of different techniques, affinity chromatography is one of the most selective, rapid and easy method for antibody purification. This review aims to provide a detailed overview on affinity chromatography and the components involved in purification. An array of support matrices along with various classes of affinity ligands detailing their underlying working principles, together with the advantages and limitations of each system in purifying different types of antibodies, accompanying recent developments and important practical methodological considerations to optimize purification procedure are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Purification of cerium, neodymium and gadolinium for low background experiments

    Directory of Open Access Journals (Sweden)

    Boiko R.S.

    2014-01-01

    Full Text Available Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search, 136Ce (2β+ candidate with one of the highest Q2β. The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical and chemical methods was applied to purify cerium, neodymium and gadolinium. Liquid-liquid extraction technique was used to remove traces of Th and U from neodymium, gadolinium and for purification of cerium from Th, U, Ra and K. Co-precipitation and recrystallization methods were utilized for further reduction of the impurities. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe gamma spectrometry. As a result of the purification procedure the radioactive contamination of gadolinium oxide (a similar purification efficiency was reached also with cerium and neodymium oxides was decreased from 0.12 Bq/kg to 0.007 Bq/kg in 228Th, from 0.04 Bq/kg to <0.006 Bq/kg in 226Ra, and from 0.9 Bq/kg to 0.04 Bq/kg in 40K. The purification methods are much less efficient for chemically very similar radioactive elements like actinium, lanthanum and lutetium.

  13. Ecophysiology of the Anammox Bacteria

    NARCIS (Netherlands)

    Kartal, M.B.

    2008-01-01

    Anaerobic ammonium oxidizing (anammox) bacteria oxidize ammonium to dinitrogen gas with nitrite as the electron acceptor. These bacteria are the key players in the global nitrogen cycle, responsible for the most of nitrogen production in natural ecosystems. The anammox process is also a

  14. Money and transmission of bacteria.

    NARCIS (Netherlands)

    Gedik, H.; Voss, T.A.; Voss, A.

    2013-01-01

    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria

  15. Rapid Two-Step Procedure for Large-Scale Purification of Pediocin-Like Bacteriocins and Other Cationic Antimicrobial Peptides from Complex Culture Medium

    Science.gov (United States)

    Uteng, Marianne; Hauge, Håvard Hildeng; Brondz, Ilia; Nissen-Meyer, Jon; Fimland, Gunnar

    2002-01-01

    A rapid and simple two-step procedure suitable for both small- and large-scale purification of pediocin-like bacteriocins and other cationic peptides has been developed. In the first step, the bacterial culture was applied directly on a cation-exchange column (1-ml cation exchanger per 100-ml cell culture). Bacteria and anionic compounds passed through the column, and cationic bacteriocins were subsequently eluted with 1 M NaCl. In the second step, the bacteriocin fraction was applied on a low-pressure, reverse-phase column and the bacteriocins were detected as major optical density peaks upon elution with propanol. More than 80% of the activity that was initially in the culture supernatant was recovered in both purification steps, and the final bacteriocin preparation was more than 90% pure as judged by analytical reverse-phase chromatography and capillary electrophoresis. PMID:11823243

  16. Filters for water purification from radionuclides

    International Nuclear Information System (INIS)

    Mironov, V.V.; Khaydarov, R.R.; Khaydarov, R.A.; Gapurova, O.U.

    2006-01-01

    Full text: At present purification of waste water and drinking water from radionuclides, heavy metal ions, and organic contaminants is one of the most important problems. One of widely used methods for solving this problem is the ion exchange method based on using of different types of resins and fibroid sorbents. This paper deals with new chemically modified polyester fibroid filters having satisfactory adsorption characteristics. The process of the filter production includes their treatment by acrylonitrilic emulsion for improving mechanical characteristics. An advantage of the fibroid ion-exchange sorbents over resin is in their high sorption rate, effective regeneration and small value of pressure drop of the sorbent layer for purified water. The specific surface of the fibroid sorbents is (2 - 3). 10 4 m 2 / kg, i.e. about 10 2 times greater than that of the resin (10 2 m 2 / kg). Owing to that fact the rate of the sorption process on the developed fibroid sorbents is much greater than that on the resin. The developed cation- and anion-exchange filters can be used for removing metal ions (Zn, Ni, Cu, Sb, Co, Cd, Cr, etc.) and organic compounds (M- 32 P, M- 131 I, M- 99 Mo+ 99m Tc, etc.) from water. Capacity of the cation-exchange sorbents is 0.25 meq/g (Cu 2+ ) and that of the anion - exchange is 0.45 meq/g (Cr 6+ ). The cation- and anion-exchange filters are also selective for removing radionuclides 134 , 137 Cs, 90 Sr, 60 Co and 129 I in presence of Na + , K + , Ca 2+ , Mg 2+ , Cl - ions in water at concentrations up to 500 mg/L. New developed ion-exchange sorbents have been used in drinking water filters and mini-systems for removing organic and inorganic contaminants, in the equipment for waste water purification from oil products (at atomic power stations, car-washing stations, etc), from heavy metal ions (in electronic industry, match fabrics, leather processing plants etc). (author)

  17. Desalination and Water Purification Technology Roadmap

    Science.gov (United States)

    2003-01-01

    Environmental Protection Agency EPS Extra-cellular Polymeric Substances M&E Materials and Energy MF Microfiltration MTBE Methyl Tertiary Butyl Ether NASA...and bays. On a regional scale, therefore, desalination could aid in restoring the balance between fresh water needs and fresh water supplies that has... Microfiltration (MF) membranes—used for turbidity reduction, removal of suspended solids and bacteria • Ultrafiltration (UF) membranes—used for color, odor

  18. Purification and functional reconstitution of a seven-subunit mrp-type na+/h+ antiporter.

    Science.gov (United States)

    Morino, Masato; Suzuki, Toshiharu; Ito, Masahiro; Krulwich, Terry Ann

    2014-01-01

    Mrp antiporters and their homologues in the cation/proton antiporter 3 family of the Membrane Transporter Database are widely distributed in bacteria. They have major roles in supporting cation and cytoplasmic pH homeostasis in many environmental, extremophilic, and pathogenic bacteria. These antiporters require six or seven hydrophobic proteins that form hetero-oligomeric complexes, while most other cation/proton antiporters require only one membrane protein for their activity. The resemblance of three Mrp subunits to membrane-embedded subunits of the NADH:quinone oxidoreductase of respiratory chains and to subunits of several hydrogenases has raised interest in the evolutionary path and commonalities of their proton-translocating domains. In order to move toward a greater mechanistic understanding of these unusual antiporters and to rigorously demonstrate that they function as secondary antiporters, powered by an imposed proton motive force, we established a method for purification and functional reconstitution of the seven-subunit Mrp antiporter from alkaliphilic Bacillus pseudofirmus OF4. Na(+)/H(+) antiporter activity was demonstrated by a fluorescence-based assay with proteoliposomes in which the Mrp complex was coreconstituted with a bacterial FoF1-ATPase. Proton pumping by the ATPase upon addition of ATP generated a proton motive force across the membranes that powered antiporter activity upon subsequent addition of Na(+).

  19. Purification and characterization of enterocin FH 99 produced by a faecal isolate Enterococcus faecium FH 99.

    Science.gov (United States)

    Gupta, H; Malik, R K; Bhardwaj, A; Kaur, G; De, S; Kaushik, J K

    2010-06-01

    Enterococcus faecium FH 99 was isolated from human faeces and selected because of its broad spectrum of inhibitory activity against several Gram-positive foodborne spoilage and pathogenic bacteria. Ent. faecium FH 99 accumulates enterocin in large number in early stationary phase of the growth. The enterocin FH 99 was stable over a wide pH range (2-10) and recovered activity even after treatment at high temperatures (10 min at 100°C). The enterocin was subjected to different purification techniques viz., gel filteration, cation exchange chromatography and reverse-phase high-performance liquid chromatography. The activity was eluted as one individual active fraction. SDSPAGE revealed a molecular weight of less than 6.5 kDa. Studies carried out to identify the genetic determinants for bacteriocin production showed that this trait may be plasmid encoded as loss in both of the plasmids (size>chromosomal DNA) led to loss in bacteriocin production by Ent. faecium FH 99. Ent. faecium strain FH 99 is a newly discovered high bacteriocin producer with Activity Units 1.8 × 10(5) AU ml(-1) and its characteristics indicate that it may have strong potential for application as a protective agent against pathogens and spoilage bacteria in foods.

  20. Purification and Characterization of Bacteriocin Produced by Weissella confusa A3 of Dairy Origin

    Science.gov (United States)

    Goh, Hweh Fen; Philip, Koshy

    2015-01-01

    A dramatic increase in bacterial resistance towards currently available antibiotics has raised worldwide concerns for public health. Therefore, antimicrobial peptides (AMPs) have emerged as a promisingly new group of therapeutic agents for managing infectious diseases. The present investigation focusses on the isolation and purification of a novel bacteriocin from an indigenous sample of cow milk and it’s mode of action. The bacteriocin was isolated from Weissella confusa A3 that was isolated from the sample and was shown to have inhibitory activity towards pathogenic bacteria namely Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Micrococcus luteus. The bacteriocin was shown to be heat stable and functioned well at low pH (2 to 6). Reduction of activity was shown after treatment with proteinase K, trypsin and peptidase that confirmed the proteinaceous nature of the compound. MALDI-TOF analysis of the sample gave a mass approximating 2.7 kDa. The membrane of the bacteria was disrupted by the bacteriocin causing SYTOX® green dye to enter the cell and bind to the bacterial DNA giving fluorescence signal. Bacterial cell treated with the bacteriocin also showed significant morphological changes under transmission electron microscope. No virulence and disease related genes can be detected from the genome of the strain. PMID:26474074