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Sample records for bacterial wax production

  1. Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion.

    Science.gov (United States)

    Aslan, Selcuk; Hofvander, Per; Dutta, Paresh; Sun, Chuanxin; Sitbon, Folke

    2015-12-01

    Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future.

  2. Oils; lubricants; paraffin-wax compositions; hydrocarbon condensation products

    Energy Technology Data Exchange (ETDEWEB)

    1934-04-04

    Petroleum hydrocarbons such as gasoline, kerosene, Diesel fuel oil, lubricating-oil, and paraffin wax, and like hydrocarbons such as are obtainable from shale oil and by the hydrogenation of carbonaceous materials, are improved by addition of products obtained by condensing a cyclic hydrocarbon with a saturated dihalogen derivative of an aliphatic hydrocarbon containing less than five carbon atoms. The addition of the condensation products increases the viscosity of the hydrocarbon oils specified, and is particularly useful in the case of lubricating-oils; addition of the condensation products to paraffin wax increases the transparency and adherent properties of the wax, and is useful in the manufacture of moulded articles such as candles; the products may also be used in solid lubricating-compositions.

  3. A news magnetic tools designed by ECOPETROL to inhibit wax in the petroleum production systems

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez U, C.; Medina Z, C. [ECOPETROL, Instituto Colombiano del Petroleo (Colombia); Pena C, A. [INSERPET, Bucaramanga (Colombia)

    1996-12-31

    The deposition of wax and asphaltenes in production systems cause plugging in the flow lines reducing the oil production and increasing significantly the produced barrels prices. A wax magnetic inhibition technique has been tested with great success. The method has been improved with the use of magnetic tools. This work describes the experience and the results obtained with these tools. 6 figs., 1 tab.

  4. A news magnetic tools designed by ECOPETROL to inhibit wax in the petroleum production systems

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez U, C; Medina Z, C [ECOPETROL, Instituto Colombiano del Petroleo (Colombia); Pena C, A [INSERPET, Bucaramanga (Colombia)

    1997-12-31

    The deposition of wax and asphaltenes in production systems cause plugging in the flow lines reducing the oil production and increasing significantly the produced barrels prices. A wax magnetic inhibition technique has been tested with great success. The method has been improved with the use of magnetic tools. This work describes the experience and the results obtained with these tools. 6 figs., 1 tab.

  5. Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils

    Energy Technology Data Exchange (ETDEWEB)

    Tao Zhu; Jack A. Walker; J. Liang

    2008-12-31

    Due to increasing oil demand, oil companies are moving into arctic environments and deep-water areas for oil production. In these regions of lower temperatures, wax deposits begin to form when the temperature in the wellbore falls below wax appearance temperature (WAT). This condition leads to reduced production rates and larger pressure drops. Wax problems in production wells are very costly due to production down time for removal of wax. Therefore, it is necessary to develop a solution to wax deposition. In order to develop a solution to wax deposition, it is essential to characterize the crude oil and study phase behavior properties. The main objective of this project was to characterize Alaskan North Slope crude oil and study the phase behavior, which was further used to develop a dynamic wax deposition model. This report summarizes the results of the various experimental studies. The subtasks completed during this study include measurement of density, molecular weight, viscosity, pour point, wax appearance temperature, wax content, rate of wax deposition using cold finger, compositional characterization of crude oil and wax obtained from wax content, gas-oil ratio, and phase behavior experiments including constant composition expansion and differential liberation. Also, included in this report is the development of a thermodynamic model to predict wax precipitation. From the experimental study of wax appearance temperature, it was found that wax can start to precipitate at temperatures as high as 40.6 C. The WAT obtained from cross-polar microscopy and viscometry was compared, and it was discovered that WAT from viscometry is overestimated. From the pour point experiment it was found that crude oil can cease to flow at a temperature of 12 C. From the experimental results of wax content, it is evident that the wax content in Alaskan North Slope crude oil can be as high as 28.57%. The highest gas-oil ratio for a live oil sample was observed to be 619.26 SCF

  6. SEPARATION OF FISCHER-TROPSCH WAX PRODUCTS FROM ULTRAFINE IRON CATALYST PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    James K. Neathery; Gary Jacobs; Burtron H. Davis

    2004-03-31

    In this reporting period, a fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of production since the reaction is highly exothermic. Consequently, heavy wax products must be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase FTS. The separation problem is further compounded by catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. Existing pilot-scale equipment was modified to include a filtration test apparatus. After undergoing an extensive plant shakedown period, filtration tests with cross-flow filter modules using simulant FTS wax slurry were conducted. The focus of these early tests was to find adequate mixtures of polyethylene wax to simulate FTS wax. Catalyst particle size analysis techniques were also developed. Initial analyses of the slurry and filter permeate particles will be used by the research team to design improved filter media and cleaning strategies.

  7. Crystallography of waxes - an electron diffraction study of refined and natural products

    Science.gov (United States)

    Dorset, Douglas L.

    1997-02-01

    The crystal structure of four waxes has been investigated by electron crystallography. Two of these waxes, including a refined petroleum product (Gulfwax) and a material from lignite (montan wax), form well ordered crystals and their structure could be solved quantitatively from the observed 0022-3727/30/3/018/img1 diffraction patterns. As also found previously for simpler binary n-paraffin solid solutions, the average structure resembles that of a pure paraffin (e.g. n-0022-3727/30/3/018/img2) but with a Gaussian distribution of atomic occupancies near the chain ends to account for the statistical distribution of chain lengths within a lamella. Two other waxes from living organisms, South African bee honeycomb and the leaves of the Brazilian carnauba palm, are much less ordered, even though they share the same methylene subcell packing of the most crystalline parts of the previous materials. It appears that these waxes cannot fully separate into distinct lamellae, perhaps due to the presence of very long `tie' molecules, and are therefore `frustrated' crystal structures.

  8. Purification of a jojoba embryo wax synthase, cloning of its cDNA, and production of high levels of wax in seeds of transgenic arabidopsis.

    Science.gov (United States)

    Lardizabal, K D; Metz, J G; Sakamoto, T; Hutton, W C; Pollard, M R; Lassner, M W

    2000-03-01

    Wax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned. Seed-specific expression of the cDNA in transgenic Arabidopsis conferred high levels of WS activity on developing embryos from those plants. The WS sequence has significant homology with several Arabidopsis open reading frames of unknown function. Wax production in jojoba requires, in addition to WS, a fatty acyl-CoA reductase (FAR) and an efficient fatty acid elongase system that forms the substrates preferred by the FAR. We have expressed the jojoba WS cDNA in Arabidopsis in combination with cDNAs encoding the jojoba FAR and a beta-ketoacyl-CoA synthase (a component of fatty acid elongase) from Lunaria annua. (13)C-Nuclear magnetic resonance analysis of pooled whole seeds from transgenic plants indicated that as many as 49% of the oil molecules in the seeds were waxes. Gas chromatography analysis of transmethylated oil from individual seeds suggested that wax levels may represent up to 70% (by weight) of the oil present in those seeds.

  9. Production of wax esters via microbial oil synthesis from food industry waste and by-product streams.

    Science.gov (United States)

    Papadaki, Aikaterini; Mallouchos, Athanasios; Efthymiou, Maria-Nefeli; Gardeli, Chryssavgi; Kopsahelis, Nikolaos; Aguieiras, Erika C G; Freire, Denise M G; Papanikolaou, Seraphim; Koutinas, Apostolis A

    2017-12-01

    The production of wax esters using microbial oils was demonstrated in this study. Microbial oils produced from food waste and by-product streams by three oleaginous yeasts were converted into wax esters via enzymatic catalysis. Palm oil was initially used to evaluate the influence of temperature and enzyme activity on wax ester synthesis catalysed by Novozyme 435 and Lipozyme lipases using cetyl, oleyl and behenyl alcohols. The highest conversion yields (up to 79.6%) were achieved using 4U/g of Novozyme 435 at 70°C. Transesterification of microbial oils to behenyl and cetyl esters was achieved at conversion yields up to 87.3% and 69.1%, respectively. Novozyme 435 was efficiently reused for six and three cycles during palm esters and microbial esters synthesis, respectively. The physicochemical properties of microbial oil derived behenyl esters were comparable to natural waxes. Wax esters from microbial oils have potential applications in cosmetics, chemical and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Effect of new type of synthetic waxes on reduced production and compaction temperature of asphalt mixture with reclaimed asphalt

    Science.gov (United States)

    Valentová, Tereza; Benešová, Lucie; Mastný, Jan; Valentin, Jan

    2017-09-01

    Lower mixing and paving temperatures of asphalt mixtures, which are an important issue in recent years, with respect to increased energy demand of civil engineering structures during their processing, allow reduction of this demand and result in minimized greenhouse gas production. In present time, there are many possibilities how to achieve reduction of production temperature during the mixing and paving of an asphalt mixture. The existing solutions distinguish in target operating temperature behaviour which has to be achieved in terms of good workability. This paper is focused on technical solutions based on use of new types of selected synthetic and bio-based waxes. In case of bio-based additive sugar cane wax was used, which is free of paraffins and is reclaimed as waste product during processing of sugar cane. The used waxes are added to bituminous binder in form of free-flowing granules or fine-grained powder. Synthetic waxes are represented by new series of Fischer-Tropsch wax in form of fine granules as well as by polyethylene waxes in form of fine-grained powder or granules. Those waxes were used to modify a standard paving grade bitumen dosed into asphalt mixture of ACsurf type containing up to 30 % of reclaimed asphalt (RA).

  11. Ear wax

    Science.gov (United States)

    See your provider if your ears are blocked with wax and you are unable to remove the wax. Also call if you have an ear wax blockage and you develop new symptoms, such as: Drainage from the ear Ear pain Fever Hearing loss that continues after you clean the wax

  12. Production of bacterial polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Ellwood, D C; Evans, C G.T.; Yeo, R G

    1978-06-01

    A process for the biochemical synthesis of polysaccharides comprises growing polysaccharide-producing bacteria of the genus Xanthomonas in a single stage continuous culture in a chemically-defined medium. The term chemically-defined medium denotes a culture medium wherein nutrients other than carbon are provided as inorganic salts or single organic compounds of known molecular structure rather than as complex naturally-derived mixtures. Normally the only organic component of the chemically-defined medium will be a conventional carbon source such as a carbohydrate, especially glucose, or glycerol. Preferably the medium should contain only one nitrogen source, since the use of multiple nitrogen sources, as present in complex media, appears to promote changes in the nature of the culture resulting in loss of polysaccharide production. 22 claims.

  13. Oleogels of virgin olive oil with carnauba wax and monoglyceride as spreadable products

    Directory of Open Access Journals (Sweden)

    Öǧütcü, M.

    2014-09-01

    Full Text Available The oleogels of virgin olive oil with carnauba wax and monoglyceride were prepared to determine the most suitable spreadable product. The oil binding capacities of monoglyceride oleogels were higher than those of the carnauba wax oleogels. There was no true crystalline structure with carnauba wax at 3%. Although the highest solid fat content was in the 10% monoglyceride oleogel (9.38%, it was 12.15% in the commercial breakfast margarine at 20 °C. The peak melting temperature of the margarine was 47.11 °C, and among all oleogels, monoglyceride oleogel at 7% addition had the closest value (48.70 °C. The melting enthalpies of the oleogels ranged from 1.25 to 103.97 J·g−1, while it was 94.19 J·g−1 for the margarine sample. The firmness and stickiness values were usually lower in the oleogel samples than those of the margarine sample. There was no significant change in the texture parameters during storage, indicating good structural stability. The polarized light microscopy pictures revealed rod-like crystals for carnauba wax and rosette-like aggregates for monoglyceride oleogels. X-ray diffraction patterns of the samples have revealed a β´-type polymorphic structure for the oleogels. These oleogels can be used in a spreadable, breakfast margarin-like product to promote new consumption habits for this healthy oil.Se prepararon oleogeles de aceites de oliva virgen con cera de carnaúba y monoglicéridos para encontrar el producto más adecuado para untar. La capacidad de unión de aceites de oleogeles de monoglicéridos fue más alto que el de los oleogeles de cera de carnaúba. No hubo ninguna estructura cristalina verdadera con cera de carnaúba al 3%. Aunque el mayor contenido de grasa sólida fue con el 10 % de oleogeles de monoglicérido (9,38 %, fue del 12.15 % en el de margarina comercial a 20 °C. La temperatura pico de fusión de la margarina fue 47,11 ºC, y entre todos los oleogeles, los de monoglicérido al 7 % tuvo el valor m

  14. The Molecular Level Characterization of Biodegradable Polymers Originated from Polyethylene Using Non-Oxygenated Polyethylene Wax as a Carbon Source for Polyhydroxyalkanoate Production.

    Science.gov (United States)

    Johnston, Brian; Jiang, Guozhan; Hill, David; Adamus, Grazyna; Kwiecień, Iwona; Zięba, Magdalena; Sikorska, Wanda; Green, Matthew; Kowalczuk, Marek; Radecka, Iza

    2017-08-28

    There is an increasing demand for bio-based polymers that are developed from recycled materials. The production of biodegradable polymers can include bio-technological (utilizing microorganisms or enzymes) or chemical synthesis procedures. This report demonstrates the corroboration of the molecular structure of polyhydroxyalkanoates (PHAs) obtained by the conversion of waste polyethylene (PE) via non-oxygenated PE wax (N-PEW) as an additional carbon source for a bacterial species. The N-PEW, obtained from a PE pyrolysis reaction, has been found to be a beneficial carbon source for PHA production with Cupriavidus necator H16. The production of the N-PEW is an alternative to oxidized polyethylene wax (O-PEW) (that has been used as a carbon source previously) as it is less time consuming to manufacture and offers fewer industrial applications. A range of molecular structural analytical techniques were performed on the PHAs obtained; which included nuclear magnetic resonance (NMR) and electrospray ionisation tandem mass spectrometry (ESI-MS/MS). Our study showed that the PHA formed from N-PEW contained 3-hydroxybutyrate (HB) with 11 mol% of 3-hydroxyvalerate (HV) units.

  15. 21 CFR 178.3710 - Petroleum wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Petroleum wax. 178.3710 Section 178.3710 Food and... and Production Aids § 178.3710 Petroleum wax. Petroleum wax may be safely used as a component of nonfood articles in contact with food, in accordance with the following conditions: (a) Petroleum wax is a...

  16. Functional expression and characterization of five wax ester synthases in Saccharomyces cerevisiae and their utility for biodiesel production

    Directory of Open Access Journals (Sweden)

    Shi Shuobo

    2012-02-01

    Full Text Available Abstract Background Wax ester synthases (WSs can synthesize wax esters from alcohols and fatty acyl coenzyme A thioesters. The knowledge of the preferred substrates for each WS allows the use of yeast cells for the production of wax esters that are high-value materials and can be used in a variety of industrial applications. The products of WSs include fatty acid ethyl esters, which can be directly used as biodiesel. Results Here, heterologous WSs derived from five different organisms were successfully expressed and evaluated for their substrate preference in Saccharomyces cerevisiae. We investigated the potential of the different WSs for biodiesel (that is, fatty acid ethyl esters production in S. cerevisiae. All investigated WSs, from Acinetobacter baylyi ADP1, Marinobacter hydrocarbonoclasticus DSM 8798, Rhodococcus opacus PD630, Mus musculus C57BL/6 and Psychrobacter arcticus 273-4, have different substrate specificities, but they can all lead to the formation of biodiesel. The best biodiesel producing strain was found to be the one expressing WS from M. hydrocarbonoclasticus DSM 8798 that resulted in a biodiesel titer of 6.3 mg/L. To further enhance biodiesel production, acetyl coenzyme A carboxylase was up-regulated, which resulted in a 30% increase in biodiesel production. Conclusions Five WSs from different species were functionally expressed and their substrate preference characterized in S. cerevisiae, thus constructing cell factories for the production of specific kinds of wax ester. WS from M. hydrocarbonoclasticus showed the highest preference for ethanol compared to the other WSs, and could permit the engineered S. cerevisiae to produce biodiesel.

  17. Oxidized Polyethylene Wax as a Potential Carbon Source for PHA Production

    Directory of Open Access Journals (Sweden)

    Iza Radecka

    2016-05-01

    Full Text Available We report on the ability of bacteria to produce biodegradable polyhydroxyalkanoates (PHA using oxidized polyethylene wax (O-PEW as a novel carbon source. The O-PEW was obtained in a process that used air or oxygen as an oxidizing agent. R. eutropha H16 was grown for 48 h in either tryptone soya broth (TSB or basal salts medium (BSM supplemented with O-PEW and monitored by viable counting. Study revealed that biomass and PHA production was higher in TSB supplemented with O-PEW compared with TSB only. The biopolymers obtained were preliminary characterized by nuclear magnetic resonance (NMR, gel permeation chromatography (GPC, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA. The detailed structural evaluation at the molecular level was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS. The study revealed that, when TSB was supplemented with O-PEW, bacteria produced PHA which contained 3-hydroxybutyrate and up to 3 mol % of 3-hydroxyvalerate and 3-hydroxyhexanoate co-monomeric units. The ESI-MS/MS enabled the PHA characterization when the content of 3-hydroxybutyrate was high and the appearance of other PHA repeating units was very low.

  18. Bacterial growth on macrophyte leachate and fate of bacterial production

    International Nuclear Information System (INIS)

    Findlay, S.; Carlough, L.; Crocker, M.T.; Gill, H.K.; Meyer, J.L.; Smith, P.J.

    1986-01-01

    The role bacteria play in transferring organic carbon to other trophic levels in aquatic ecosystems depends on the efficiency with which they convert dissolved organic [ 14 C]-labelled carbon into bacterial biomass and on the ability of consumers to graze bacteria. The authors have measured the conversion efficiency for bacteria growing on macrophyte-derived dissolved organic carbon and estimated the amount of bacterial production removed by grazing. Bacteria converted this DOC into new tissue with an efficiency of 53%, substantially higher than the apparent conversion efficiency of macrophyte-derived particulate organic carbon or other types of DOC. Two estimates of grazing indicate that the decline in bacterial numbers after the bloom was probably due to grazing by flagellates. These results show the significance of the bacterial link between DOC and other trophic levels

  19. THERMOLYSIS OF FOAM PRODUCTS FORMED AT THE FLOTATION EXTRACTION OF COPPER AND NICKEL IONS BY HELP OF WAX PEAT

    Directory of Open Access Journals (Sweden)

    V. F. Sazonova

    2015-02-01

    Full Text Available There thermogravimetric study of foam product at the flotation extraction of cop­per and nickel ions by wax peat results are described. It shown that oxidizing roasting of foam products (i.e. hydrated soaps of polyvalent metals proceeds in several steps. At the first step (t<100 °С dehydration takes place. At the next ones (t=160^665 °С The thermic destruction and burning of organic compounds occurs. The residue is the of metal oxides.

  20. 21 CFR 582.1978 - Carnauba wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carnauba wax. 582.1978 Section 582.1978 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1978 Carnauba wax. (a) Product. Carnauba wax. (b) Conditions of use. This substance is generally...

  1. Integrated Process for Extraction of Wax as a Value-Added Co-Product and Improved Ethanol Production by Converting Both Starch and Cellulosic Components in Sorghum Grains

    Directory of Open Access Journals (Sweden)

    Nhuan P. Nghiem

    2018-02-01

    Full Text Available Grain sorghum is a potential feedstock for fuel ethanol production due to its high starch content, which is equivalent to that of corn, and has been successfully used in several commercial corn ethanol plants in the United States. Some sorghum grain varieties contain significant levels of surface wax, which may interact with enzymes and make them less efficient toward starch hydrolysis. On the other hand, wax can be recovered as a valuable co-product and as such may help improve the overall process economics. Sorghum grains also contain lignocellulosic materials in the hulls, which can be converted to additional ethanol. An integrated process was developed, consisting of the following steps: 1. Extraction of wax with boiling ethanol, which is the final product of the proposed process; 2. Pretreatment of the dewaxed grains with dilute sulfuric acid; 3. Mashing and fermenting of the pretreated grains to produce ethanol. During the fermentation, commercial cellulase was also added to release fermentable sugars from the hulls, which then were converted to additional ethanol. The advantages of the developed process were illustrated with the following results: (1 Wax extracted (determined by weight loss: ~0.3 wt % of total mass. (2 Final ethanol concentration at 25 wt % solid using raw grains: 86.1 g/L. (3 Final ethanol concentration at 25 wt % solid using dewaxed grains: 106.2 g/L (23.3% improvement. (4 Final ethanol concentration at 25 wt % solid using dewaxed and acid-treated grains (1 wt % H2SO4 plus cellulase (CTec2: 117.8 g/L (36.8% improvement.

  2. Bacterial production of methyl ketones

    Energy Technology Data Exchange (ETDEWEB)

    Beller, Harry R.; Goh, Ee-Been

    2017-01-31

    The present invention relates to methods and compositions for increasing production of methyl ketones in a genetically modified host cell that overproduces .beta.-ketoacyl-CoAs through a re-engineered .beta.-oxidation pathway and overexpresses FadM.

  3. Enhanced ethanol production by removal of cutin and epicuticular waxes of wheat straw by plasma assisted pretreatment

    DEFF Research Database (Denmark)

    Kádár, Zsófia; Schultz-Jensen, Nadja; Jensen, J. S.

    2015-01-01

    as with Scanning Electron Microscopy (SEM) imaging. Compounds resulting from wax degradation were analyzed in the washing water of PAP wheat straw. The wax removal enhanced enzymatic hydrolysis yield and, consequently, the efficiency of wheat straw conversion into ethanol. In total, PAP increased the conversion...

  4. Molecular and Evolutionary Mechanisms of Cuticular Wax for Plant Drought Tolerance

    Directory of Open Access Journals (Sweden)

    Dawei Xue

    2017-04-01

    Full Text Available Cuticular wax, the first protective layer of above ground tissues of many plant species, is a key evolutionary innovation in plants. Cuticular wax safeguards the evolution from certain green algae to flowering plants and the diversification of plant taxa during the eras of dry and adverse terrestrial living conditions and global climate changes. Cuticular wax plays significant roles in plant abiotic and biotic stress tolerance and has been implicated in defense mechanisms against excessive ultraviolet radiation, high temperature, bacterial and fungal pathogens, insects, high salinity, and low temperature. Drought, a major type of abiotic stress, poses huge threats to global food security and health of terrestrial ecosystem by limiting plant growth and crop productivity. The composition, biochemistry, structure, biosynthesis, and transport of plant cuticular wax have been reviewed extensively. However, the molecular and evolutionary mechanisms of cuticular wax in plants in response to drought stress are still lacking. In this review, we focus on potential mechanisms, from evolutionary, molecular, and physiological aspects, that control cuticular wax and its roles in plant drought tolerance. We also raise key research questions and propose important directions to be resolved in the future, leading to potential applications of cuticular wax for water use efficiency in agricultural and environmental sustainability.

  5. Bacterial production of the biodegradable plastics polyhydroxyalkanoates.

    Science.gov (United States)

    Urtuvia, Viviana; Villegas, Pamela; González, Myriam; Seeger, Michael

    2014-09-01

    Petroleum-based plastics constitute a major environmental problem due to their low biodegradability and accumulation in various environments. Therefore, searching for novel biodegradable plastics is of increasing interest. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are biodegradable plastics. Life cycle assessment indicates that PHB is more beneficial than petroleum-based plastics. In this report, bacterial production of PHAs and their industrial applications are reviewed and the synthesis of PHAs in Burkholderia xenovorans LB400 is described. PHAs are synthesized by a large number of microorganisms during unbalanced nutritional conditions. These polymers are accumulated as carbon and energy reserve in discrete granules in the bacterial cytoplasm. 3-hydroxybutyrate and 3-hydroxyvalerate are two main PHA units among 150 monomers that have been reported. B. xenovorans LB400 is a model bacterium for the degradation of polychlorobiphenyls and a wide range of aromatic compounds. A bioinformatic analysis of LB400 genome indicated the presence of pha genes encoding enzymes of pathways for PHA synthesis. This study showed that B. xenovorans LB400 synthesize PHAs under nutrient limitation. Staining with Sudan Black B indicated the production of PHAs by B. xenovorans LB400 colonies. The PHAs produced were characterized by GC-MS. Diverse substrates for the production of PHAs in strain LB400 were analyzed. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Bacterial Populations Associated with Smokeless Tobacco Products

    Science.gov (United States)

    Han, Jing; Sanad, Yasser M.; Deck, Joanna; Sutherland, John B.; Li, Zhong; Walters, Matthew J.; Duran, Norma; Holman, Matthew R.

    2016-01-01

    ABSTRACT There are an estimated 8 million users of smokeless tobacco products (STPs) in the United States, and yet limited data on microbial populations within these products exist. To better understand the potential microbiological risks associated with STP use, a study was conducted to provide a baseline microbiological profile of STPs. A total of 90 samples, representing 15 common STPs, were purchased in metropolitan areas in Little Rock, AR, and Washington, DC, in November 2012, March 2013, and July 2013. Bacterial populations were evaluated using culture, pyrosequencing, and denaturing gradient gel electrophoresis (DGGE). Moist-snuff products exhibited higher levels of bacteria (average of 1.05 × 106 CFU/g STP) and diversity of bacterial populations than snus (average of 8.33 × 101 CFU/g STP) and some chewing tobacco products (average of 2.54 × 105 CFU/g STP). The most common species identified by culturing were Bacillus pumilus, B. licheniformis, B. safensis, and B. subtilis, followed by members of the genera Oceanobacillus, Staphylococcus, and Tetragenococcus. Pyrosequencing analyses of the 16S rRNA genes identified the genera Tetragenococcus, Carnobacterium, Lactobacillus, Geobacillus, Bacillus, and Staphylococcus as the predominant taxa. Several species identified are of possible concern due to their potential to cause opportunistic infections and reported abilities to reduce nitrates to nitrites, which may be an important step in the formation of carcinogenic tobacco-specific N′-nitrosamines. This report provides a microbiological baseline to help fill knowledge gaps associated with microbiological risks of STPs and to inform potential regulations regarding manufacture and testing of STPs. IMPORTANCE It is estimated that there 8 million users of smokeless tobacco products (STPs) in the United States; however, there are limited data on microbial populations that exist within these products. The current study was undertaken to better understand the

  7. New advances in hydrogen production via the catalytic decomposition of wax by-products using nanoparticles of SBA frame-worked MoO_3

    International Nuclear Information System (INIS)

    El Naggar, Ahmed M.A.; Gobara, Heba M.; El Sayed, Hussien A.; Soliman, Fathi S.

    2015-01-01

    Graphical abstract: Feedstock-to-gases & hydrogen conversion using the Mo-SBA15 catalyst compared to commercial catalysts. - Highlights: • Synthesis of meso-porous molybdenum oxide catalyst in SBA framework. • Confirming the structural characteristics of this catalyst by different analyses. • New trend for the H_2 & CH_4, production is revealed in this work. • Nano-carbon species of well-ordered structure was produced. • In-situ non-pressurized-low temperature wax isomerization was imposed. - Abstract: The alternative energy sources in general and hydrogen based energy in particular have been currently grabbing great attention. Hydrogen is an efficient green source for power generation owing to its huge energy content. The operational costs and the hydrogen output are the key factors in the selection of a certain technique for the hydrogen production industrially. This study summarizes a new route for hydrogen production starting from a bit complicated hydrogen-containing molecules. Particular attention is given during this work towards a direct pyrrolysis catalytic conversion of long chains n-paraffin into hydrogen with in-situ production of nano-structured carbon particles. The simultaneous isomerization of the n-paraffin contented in the feedstock is also discussed during this process. This research study had provided new advances in the hydrogen production based on carrying out the production process at non-severe conditions namely; low operational temperatures and no pressure was applied. The introduction of a meso-porous molybdenum oxide catalyst for the catalytic hydrogen production is also a point of novelty for the presented work. Promising results have been disclosed at the end of this investigation; approximately 60 wt.% of the feedstock was converted to fuel gases while nearly 30 wt.% of the feed had turned as nano-carbon species. The hydrogen productivity had been detected as high as 42 wt.% of the original feedstock. This in fact might

  8. Paraffin wax

    Energy Technology Data Exchange (ETDEWEB)

    Elborne, W

    1917-06-16

    Powdered, granulated, or finely divided paraffin is obtained by subjecting paraffin to a grinding, crushing, or disintegrating operation in the presence of an alcohol such as ethyl alcohol, methyl alcohol (wood spirit), or methylated spirit. The alcohol is afterwards removed by a current of air and is recovered. The product can be used in conjunction with a heating-agent for producing smoke or vapor for use in warfare.

  9. Wax deposition in crude oil pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Assuncao, Pablo Morelato; Rodrigues, Lorennzo Marrochi Nolding [Universidade Federal do Espirito Santo, Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Engenharia de Petroleo; Romero, Mao Ilich [University of Wyoming, Laramie, WY (United States). Enhanced Oil Recovery Institute], e-mail: mromerov@uwyo.edu

    2010-07-01

    Crude oil is a complex mixture of hydrocarbons which consists of aromatics, paraffins, naphthenics, resins asphaltenes, etc. When the temperature of crude oil is reduced, the heavy components, like paraffin, will precipitate and deposit on the pipe internal wall in the form of a wax-oil gel. The gel deposit consists of wax crystals that trap some amount of oil. As the temperature gets cooler, more wax will precipitate and the thickness of the wax gel will increase, causing gradual solidification of the crude and eventually the oil stop moving inside the offshore pipeline. Crude oil may not be able to be re-mobilized during re-startup. The effective diameter will be reduced with wax deposition, resulting in several problems, for example, higher pressure drop which means additional pumping energy costs, poor oil quality, use of chemical components like precipitation inhibitors or flowing facilitators, equipment failure, risk of leakage, clogging of the ducts and process equipment. Wax deposition problems can become so sever that the whole pipeline can be completely blocked. It would cost millions of dollars to remediate an offshore pipeline that is blocked by wax. Wax solubility decreases drastically with decreasing temperature. At low temperatures, as encountered in deep water production, is easy to wax precipitate. The highest temperature below which the paraffins begins to precipitate as wax crystals is defined as wax appearance temperature (WAT). Deposition process is a complex free surface problem involving thermodynamics, fluid dynamics, mass and heat transfer. In this work, a numerical analysis of wax deposition by molecular diffusion and shear dispersion mechanisms in crude oil pipeline is studied. Diffusion flux of wax toward the wall is estimated by Fick's law of diffusion, in similar way the shear dispersion; wax concentration gradient at the solid-liquid interface is obtained by the volume fraction conservation equation; and since the wax deposition

  10. Preparing paraffin wax, etc

    Energy Technology Data Exchange (ETDEWEB)

    1935-12-27

    A process is described for preparing paraffin wax by separation from substances containing bitumen, consisting of treating the raw material at an elevated temperature under such moderate conditions and by means of such organic solvents that the bitumen present in the raw material or formed in the process dissolves as well as the asphaltic and phenolic substances and the humic acids which may be said to be neither extracts nor decomposed materials, and then submitting the products and extracts to a treatment with hydrogen gas, which is effected below 300/sup 0/C, and passing the material over fixed hydrogenation catalysts above 300/sup 0/C by means of hydrogenation catalysts finely dispersed in carbonaceous materials all avoiding decomposition with the formation of volatile products.

  11. Production of long chain alkyl esters from carbon dioxide and electricity by a two-stage bacterial process.

    Science.gov (United States)

    Lehtinen, Tapio; Efimova, Elena; Tremblay, Pier-Luc; Santala, Suvi; Zhang, Tian; Santala, Ville

    2017-11-01

    Microbial electrosynthesis (MES) is a promising technology for the reduction of carbon dioxide into value-added multicarbon molecules. In order to broaden the product profile of MES processes, we developed a two-stage process for microbial conversion of carbon dioxide and electricity into long chain alkyl esters. In the first stage, the carbon dioxide is reduced to organic compounds, mainly acetate, in a MES process by Sporomusa ovata. In the second stage, the liquid end-products of the MES process are converted to the final product by a second microorganism, Acinetobacter baylyi in an aerobic bioprocess. In this proof-of-principle study, we demonstrate for the first time the bacterial production of long alkyl esters (wax esters) from carbon dioxide and electricity as the sole sources of carbon and energy. The process holds potential for the efficient production of carbon-neutral chemicals or biofuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Process for separating liquid hydrocarbons from waxes

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, F J

    1948-03-08

    A process is described for the separation of liquid hydrocarbons from waxes comprising adding to a mixture of liquid hydrocarbons and waxes a sufficient quantity of an organo-silicon compound to cause the separation of the hydrocarbon and wax. The organo-silicon compounds are selected from the class of organic silicanes and their hydrolysis products and polymers. The silicanes have the formula R/sub y/SiX/sub z/, in which R is a saturated or unsaturated hydrocarbon radical, X is a halogen or another hydrocarbon radical or an -OR group, y has a value 1, 2, or 3 and z has a value 1, 2, or 3.

  13. THE PRODUCTION OF COMPLEX PROFILE DETAILS BY COMBINED METHOD OF LOST-WAX CASTING AND OF CONSUMABLE PATTERN MODELS

    Directory of Open Access Journals (Sweden)

    O. I. Shinsky

    2016-01-01

    Full Text Available The technological process of receiving figurine castings of a heat resisting alloy HN57KTVYuMBL brand developed and tested by authors a combined method of oflost-wax casting (pouring gate system and of consumable expanded polystyrene pattern in shell forms kompleks modify ceramics promotes decrease in crack formation of forms at the expense of correctly picked up temperature and time mode of annealing of a form with model. Besides this method allows to receive figurine castings with minimization of an allowance for machining of details, to increase their geometrical accuracy and to lower a roughness.

  14. Estimation of bacterial hydrogen sulfide production in vitro

    Directory of Open Access Journals (Sweden)

    Amina Basic

    2015-06-01

    Full Text Available Oral bacterial hydrogen sulfide (H2S production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways.

  15. Microencapsulation of Flavors in Carnauba Wax

    OpenAIRE

    Milanovic, Jelena; Manojlovic, Verica; Levic, Steva; Rajic, Nevenka; Nedovic, Viktor; Bugarski, Branko

    2010-01-01

    The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at aroun...

  16. Bacterial community affects toxin production by Gymnodinium catenatum.

    Directory of Open Access Journals (Sweden)

    Maria E Albinsson

    Full Text Available The paralytic shellfish toxin (PST-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01 and grown with: 1 complex bacterial communities derived from each of the two parent cultures; 2 simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3 a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell of clonal offspring (134-197 fmol STX cell(-1 was similar to the parent cultures (169-206 fmol STX cell(-1, however cultures grown with single bacterial types contained less toxin (134-146 fmol STX cell(-1 than offspring or parent cultures grown with more complex mixed bacterial communities (152-176 fmol STX cell(-1. Specific toxin production rate (fmol STX day(-1 was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell(-1 day(-1 did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX

  17. Bacterial community affects toxin production by Gymnodinium catenatum.

    Science.gov (United States)

    Albinsson, Maria E; Negri, Andrew P; Blackburn, Susan I; Bolch, Christopher J S

    2014-01-01

    The paralytic shellfish toxin (PST)-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01) and grown with: 1) complex bacterial communities derived from each of the two parent cultures; 2) simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3) a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell) of clonal offspring (134-197 fmol STX cell(-1)) was similar to the parent cultures (169-206 fmol STX cell(-1)), however cultures grown with single bacterial types contained less toxin (134-146 fmol STX cell(-1)) than offspring or parent cultures grown with more complex mixed bacterial communities (152-176 fmol STX cell(-1)). Specific toxin production rate (fmol STX day(-1)) was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell(-1) day(-1)) did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX

  18. Effects of Fe nanoparticles on bacterial growth and biosurfactant production

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jia; Vipulanandan, Cumaraswamy, E-mail: cvipulanandan@uh.edu [University of Houston, Department of Civil and Environmental Engineering (United States); Cooper, Tim F. [University of Houston, Department of Biology and Biochemistry (United States); Vipulanandan, Geethanjali [University of Houston, Department of Biomedical Engineering (United States)

    2013-01-15

    Environmental conditions can have a major impact on bacterial growth and production of secondary products. In this study, the effect of different concentrations of Fe nanoparticles on the growth of Serratia sp. and on its production of a specific biosurfactant was investigated. The Fe nanoparticles were produced using the foam method, and the needle-shaped nanoparticles were about 30 nm in diameter. It was found that Fe nanoparticles can have either a positive or a negative impact on the bacterial growth and biosurfactant production, depending on their concentration. At 1 mg/L of Fe nanoparticle concentration the bacterial growth increased by 57 % and biosurfactant production increased by 63 %. When the Fe nanoparticle concentration was increased to 1 g/L, the bacterial growth decreased by 77 % and biosurfactant activity was undetectable. The biosurfactant itself was not directly affected by Fe nanoparticles over the range of concentrations studied, indicating that the observed changes in biosurfactant activity resulted indirectly from the effect of nanoparticles on the bacteria. These negative effects with nanoparticle exposures were temporary, demonstrated by the restoration of biosurfactant activity when the bacteria initially exposed to Fe nanoparticles were allowed to regrow in the absence of nanoparticles. Finally, the kinetics of bacterial growth and biosurfactant production were modeled. The model's predictions agreed with the experimental results.

  19. Effects of Fe nanoparticles on bacterial growth and biosurfactant production

    Science.gov (United States)

    Liu, Jia; Vipulanandan, Cumaraswamy; Cooper, Tim F.; Vipulanandan, Geethanjali

    2013-01-01

    Environmental conditions can have a major impact on bacterial growth and production of secondary products. In this study, the effect of different concentrations of Fe nanoparticles on the growth of Serratia sp. and on its production of a specific biosurfactant was investigated. The Fe nanoparticles were produced using the foam method, and the needle-shaped nanoparticles were about 30 nm in diameter. It was found that Fe nanoparticles can have either a positive or a negative impact on the bacterial growth and biosurfactant production, depending on their concentration. At 1 mg/L of Fe nanoparticle concentration the bacterial growth increased by 57 % and biosurfactant production increased by 63 %. When the Fe nanoparticle concentration was increased to 1 g/L, the bacterial growth decreased by 77 % and biosurfactant activity was undetectable. The biosurfactant itself was not directly affected by Fe nanoparticles over the range of concentrations studied, indicating that the observed changes in biosurfactant activity resulted indirectly from the effect of nanoparticles on the bacteria. These negative effects with nanoparticle exposures were temporary, demonstrated by the restoration of biosurfactant activity when the bacteria initially exposed to Fe nanoparticles were allowed to regrow in the absence of nanoparticles. Finally, the kinetics of bacterial growth and biosurfactant production were modeled. The model's predictions agreed with the experimental results.

  20. Effects of Fe nanoparticles on bacterial growth and biosurfactant production

    International Nuclear Information System (INIS)

    Liu Jia; Vipulanandan, Cumaraswamy; Cooper, Tim F.; Vipulanandan, Geethanjali

    2013-01-01

    Environmental conditions can have a major impact on bacterial growth and production of secondary products. In this study, the effect of different concentrations of Fe nanoparticles on the growth of Serratia sp. and on its production of a specific biosurfactant was investigated. The Fe nanoparticles were produced using the foam method, and the needle-shaped nanoparticles were about 30 nm in diameter. It was found that Fe nanoparticles can have either a positive or a negative impact on the bacterial growth and biosurfactant production, depending on their concentration. At 1 mg/L of Fe nanoparticle concentration the bacterial growth increased by 57 % and biosurfactant production increased by 63 %. When the Fe nanoparticle concentration was increased to 1 g/L, the bacterial growth decreased by 77 % and biosurfactant activity was undetectable. The biosurfactant itself was not directly affected by Fe nanoparticles over the range of concentrations studied, indicating that the observed changes in biosurfactant activity resulted indirectly from the effect of nanoparticles on the bacteria. These negative effects with nanoparticle exposures were temporary, demonstrated by the restoration of biosurfactant activity when the bacteria initially exposed to Fe nanoparticles were allowed to regrow in the absence of nanoparticles. Finally, the kinetics of bacterial growth and biosurfactant production were modeled. The model’s predictions agreed with the experimental results.

  1. Bacterial spoilage of meat and cured meat products

    NARCIS (Netherlands)

    Borch, E.; Kant-Muermans, M.L.T.; Blixt, Y.

    1996-01-01

    The influence of environmental factors (product composition and storage conditions) on the selection, growth rate and metabolic activity of the bacterial flora is presented for meat (pork and beef) and cooked, cured meat products. The predominant bacteria associated with spoilage of refrigerated

  2. Bacterial community changes in an industrial algae production system.

    Science.gov (United States)

    Fulbright, Scott P; Robbins-Pianka, Adam; Berg-Lyons, Donna; Knight, Rob; Reardon, Kenneth F; Chisholm, Stephen T

    2018-04-01

    While microalgae are a promising feedstock for production of fuels and other chemicals, a challenge for the algal bioproducts industry is obtaining consistent, robust algae growth. Algal cultures include complex bacterial communities and can be difficult to manage because specific bacteria can promote or reduce algae growth. To overcome bacterial contamination, algae growers may use closed photobioreactors designed to reduce the number of contaminant organisms. Even with closed systems, bacteria are known to enter and cohabitate, but little is known about these communities. Therefore, the richness, structure, and composition of bacterial communities were characterized in closed photobioreactor cultivations of Nannochloropsis salina in F/2 medium at different scales, across nine months spanning late summer-early spring, and during a sequence of serially inoculated cultivations. Using 16S rRNA sequence data from 275 samples, bacterial communities in small, medium, and large cultures were shown to be significantly different. Larger systems contained richer bacterial communities compared to smaller systems. Relationships between bacterial communities and algae growth were complex. On one hand, blooms of a specific bacterial type were observed in three abnormal, poorly performing replicate cultivations, while on the other, notable changes in the bacterial community structures were observed in a series of serial large-scale batch cultivations that had similar growth rates. Bacteria common to the majority of samples were identified, including a single OTU within the class Saprospirae that was found in all samples. This study contributes important information for crop protection in algae systems, and demonstrates the complex ecosystems that need to be understood for consistent, successful industrial algae cultivation. This is the first study to profile bacterial communities during the scale-up process of industrial algae systems.

  3. Benthic bacterial biomass and production in the Hudson River estuary

    International Nuclear Information System (INIS)

    Austin, H.K.; Findlay, S.E.G.

    1989-01-01

    Bacterial biomass, production, and turnover were determined for two freshwater march sites and a site in the main river channel along the tidally influenced Hudson River. The incorporation of [methyl- 3 H]thymidine into DNA was used to estimate the growth rate of surface and anaerobic bacteria. Bacterial production at marsh sites was similar to, and in some cases considerably higher than, production estimates reported for other aquatic wetland and marine sediment habitats. Production averaged 1.8-2.8 mg C·m -2 · hour -1 in marsh sediments. Anaerobic bacteria in marsh sediment incorporated significant amounts of [methyl- 3 H]thymidine into DNA. Despite differences in dominant vegatation and tidal regime, bacterial biomass was similar (1 x 10 3 ± 0.08 mg C·m -2 ) in Trapa, Typha, and Nuphar aquatic macrophyte communities. Bacterial abundance and productivity were lower in sandy sediments associated with Scirpus communities along the Hudson River (0.2 x 10 3 ± 0.05 mg C·m -2 and 0.3 ± 0.23 mg C · m -2 · hour -1 , respectively)

  4. Wax Point Determinations Using Acoustic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bostick, D.T.; Jubin, R.T.; Schmidt, T.W.

    2001-06-01

    The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, Fl. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed. The purpose of this Cooperative Research and Development Agreement (CRADA) between Phillips Petroleum Company, Inc. (Participant) and Lockheed Martin Energy Research Corporation (Contractor) was the measurement of the formation of solids in crude oils and petroleum products that are commonly transported through pipelines. This information is essential in the proper design, operation and maintenance of the petroleum pipeline system in the United States. Recently, new petroleum discoveries in the Gulf of Mexico have shown that there is a potential for plugging of undersea pipeline because of the precipitation of wax. It is important that the wax points of the expected crude oils be well characterized so that the production facilities for these new wells are capable of properly transporting the expected production. The goal of this work is to perform measurements of solids formation in crude oils and petroleum products supplied by the Participant. It is

  5. Production of extremophilic bacterial cellulase enzymes in aspergillus niger.

    Energy Technology Data Exchange (ETDEWEB)

    Gladden, John Michael

    2013-09-01

    Enzymes can be used to catalyze a myriad of chemical reactions and are a cornerstone in the biotechnology industry. Enzymes have a wide range of uses, ranging from medicine with the production of pharmaceuticals to energy were they are applied to biofuel production. However, it is difficult to produce large quantities of enzymes, especially if they are non-native to the production host. Fortunately, filamentous fungi, such as Aspergillus niger, are broadly used in industry and show great potential for use a heterologous enzyme production hosts. Here, we present work outlining an effort to engineer A. niger to produce thermophilic bacterial cellulases relevant to lignocellulosic biofuel production.

  6. Microencapsulation of Flavors in Carnauba Wax

    Directory of Open Access Journals (Sweden)

    Branko Bugarski

    2010-01-01

    Full Text Available The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM, while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.

  7. Microencapsulation of flavors in carnauba wax.

    Science.gov (United States)

    Milanovic, Jelena; Manojlovic, Verica; Levic, Steva; Rajic, Nevenka; Nedovic, Viktor; Bugarski, Branko

    2010-01-01

    The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.

  8. Bacterial chromate reduction and product characterization

    International Nuclear Information System (INIS)

    Mehlhorn, R.J.; Buchanan, B.B.; Leighton, T.

    1992-11-01

    Bacillus subtilis reduced hexavalent chromate to trivalent chromium under either aerobic or anaerobic conditions. Reduction of CR(VI) and appearance of extracellular Cr(III) were demonstrated by electron spin resonance and spectrophotometry. Chromate reduction was stimulated more than five-fold by freeze-thawing, indicating that intracellular reductases or chemical reductants reduce chromate more rapidly than do intact cells. Moderately concentrated cells (10% pellet volume after centrifugation) reduced approximately 40 μM chromate/min (2 mg Cr/1-min) when exposed to 100 μM chromate (5 mg Cr/1). Highly concentrated cells (70% pellet volume) reduced more than 99.8% of 2 mM chromate (100 mg Cr/1) within 15 min. This rate of chromate reduction was of the same order of magnitude as the rate of respiration in aerobic cells. A substantial fraction of the reduction product (ca. 75%) was extracellular Cr(M), which could readily be separated from the cells by centrifugation. At high chromate concentrations, some fraction of reduced CR(VI) appeared to be taken up by cells, consistent with a detection of intracellular paramagnetic products. At low chromate concentrations, undefined growth medium alone reduced Cr(VI), but at a slow rate, relative to cells. Under appropriate conditions, B. subtilis appears to be an organism of choice for detoxifying chromate-contaminated soil and water

  9. Effects of a wax organogel and alginate gel complex on holy basil (Ocimum sanctum) in vitro ruminal dry matter disappearance and gas production.

    Science.gov (United States)

    Templeman, James R; Rogers, Michael A; Cant, John P; McBride, Brian W; Osborne, Vern R

    2018-02-20

    The objectives of this study were to: (a) select an ideal organogel for the oil phase of a novel gel encapsulation technology, (b) optimize the formulation of an organogel and sodium alginate-based gel complex, and (c) examine the rumen protective ability of the gel by measuring 48-h in vitro ruminal dry matter disappearance and gas production from encapsulated dried and ground holy basil leaves. A rice-bran wax and canola oil organogel was selected for the oil phase of the gel complex as this combination had a 48-h dry matter disappearance of 6%, the lowest of all organogels analyzed. The gel complex was formulated by homogenizing the organogel with a sodium alginate solution to create a low-viscosity oil-in-water emulsion. Average dry matter disappearance of gel-encapsulated holy basil was 19%, compared to 42% for the free, unprotected holy basil. However, gel encapsulation of holy basil stimulated gas production. Specifically, gas production of encapsulated holy basil was four times higher than the treatment with holy basil added on top of the gel prior to incubation rather than encapsulated within the gel. Although the gel itself was highly degradable, it is speculated encapsulation thwarted holy basil's antimicrobial activity. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  10. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

    Science.gov (United States)

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-02-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

  11. Geometric accuracy of wax bade models manufactured in silicon moulds

    Directory of Open Access Journals (Sweden)

    G. Budzik

    2010-01-01

    Full Text Available The article presents the test results of the geometric accuracy of wax blade models manufactured in silicon moulds in the Rapid Tooling process, with the application of the Vacuum Casting technology. In batch production casting waxes are designed for the manufacture of models and components of model sets through injection into a metal die. The objective of the tests was to determine the possibility of using traditional wax for the production of casting models in the rapid prototyping process. Blade models made of five types of casting wax were measured. The definition of the geometric accuracy of wax blade models makes it possible to introduce individual modifications aimed at improving their shape in order to increase the dimensional accuracy of blade models manufactured in the rapid prototyping process.

  12. Factors limiting heterotrophic bacterial production in the southern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    F. Van Wambeke

    2008-05-01

    Full Text Available The role of potential factors limiting bacterial growth was investigated along vertical and longitudinal gradients across the South Eastern Pacific Gyre. The effects of glucose, nitrate, ammonium and phosphate additions on heterotrophic bacterial production (using leucine technique were studied in parallel in unfiltered seawater samples incubated under natural daily irradiance. The enrichments realized on the subsurface showed three types of responses. From 141° W (Marquesas plateau to approx 125° W, bacteria were not bottom-up controlled, as confirmed by the huge potential of growth in non-enriched seawater (median of enhancement factor×39 in 24 h. Within the Gyre (125° W–95° W, nitrogen alone stimulated leucine incorporation rates (median×4.2, but rapidly labile carbon (glucose became a second limiting factor (median×37 when the two elements were added. Finally from the border of the gyre to the Chilean upwelling (95° W–73° W, labile carbon was the only factor stimulating heterotrophic bacterial production. Interaction between phytoplankton and heterotrophic bacterial communities and the direct versus indirect effect of iron and macronutrients on bacterial production were also investigated in four selected sites: two sites on the vicinity of the Marquesas plateau, the centre of the gyre and the Eastern border of the gyre. Both phytoplankton and heterotrophic bacteria were limited by availability of nitrogen within the gyre, but not by iron. Iron limited phytoplankton at Marquesas plateau and at the eastern border of the gyre. However 48 h enrichment experiments were not sufficient to show any clear limitation of heterotrophic bacteria within Marquesas plateau and showed a limitation of these organisms by labile carbon in the eastern border of the Gyre.

  13. Bacterial Cellulose Production from Industrial Waste and by-Product Streams.

    Science.gov (United States)

    Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis

    2015-07-01

    The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102-138 g · water/g · dry bacterial cellulose, viscosities of 4.7-9.3 dL/g, degree of polymerization of 1889.1-2672.8, stress at break of 72.3-139.5 MPa and Young's modulus of 0.97-1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

  14. Bacterial Cellulose Production from Industrial Waste and by-Product Streams

    Directory of Open Access Journals (Sweden)

    Erminda Tsouko

    2015-07-01

    Full Text Available The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L and commercial sucrose (4.9 g/L were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

  15. Methods for analysis of bacterial autoinducer-2 production.

    Science.gov (United States)

    Taga, Michiko E

    2005-07-01

    The quorum-sensing signal molecule autoinducer-2 (AI-2) is produced by over 50 diverse bacterial species and controls many different processes, including antibiotic production, biofilm formation, and virulence. AI-2 production often varies according to growth phase, media conditions, and the presence of specific factors. This unit describes a biological assay for AI-2 activity produced by a bacterial strain of interest. The assay employs an AI-2 reporter strain, Vibrio harveyi BB170, which produces light in response to AI-2. In the first stage of the assay, culture fluids of the bacterial strain of interest are collected over a time course of growth and filtered to remove cells. In the next stage, these culture fluids are mixed with BB170, and the light produced in response to AI-2 in the culture fluids is measured using a luminometer. BB170 is exquisitely sensitive to AI-2, and therefore, even low amounts of AI-2 can be detected using this bioassay.

  16. Biogenic amine formation and bacterial contribution in Natto products.

    Science.gov (United States)

    Kim, Bitna; Byun, Bo Young; Mah, Jae-Hyung

    2012-12-01

    Twenty-one Natto products currently distributed in Korea were analysed for biogenic amine contents and tested to determine physicochemical and bacterial contributions to biogenic amine formation. Among them, nine products (about 43%) had β-phenylethylamine or tyramine contents greater than the toxic dose (30mg/kg and 100mg/kg, respectively) of each amine, although no products showed total amounts of biogenic amines above the harmful level (1000mg/kg), which indicates that the amounts of biogenic amines in some Natto products are not within the safe level for human health. From four different Natto products, that contained noticeable levels of β-phenylethylamine and tyramine, 80 bacterial strains were isolated. All the strains were identified to be Bacillus subtilis and highly capable of producing β-phenylethylamine and tyramine. Therefore, it seems likely that the remarkable contents of β-phenylethylamine and tyramine in Natto predominantly resulted from the strains highly capable of producing those amines present in the food. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. 21 CFR 184.1978 - Carnauba wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carnauba wax. 184.1978 Section 184.1978 Food and... Substances Affirmed as GRAS § 184.1978 Carnauba wax. (a) Carnauba wax (CAS Reg. No. 008-015-869) is obtained from the leaves and buds of the Brazilian wax palm Copernicia cerifera Martius. The wax is hard...

  18. Bacterial laccase: recent update on production, properties and industrial applications.

    Science.gov (United States)

    Chauhan, Prakram Singh; Goradia, Bindi; Saxena, Arunika

    2017-10-01

    Laccases (benzenediol: oxygen oxidoreductase, EC 1.10.3.2) are multi-copper enzymes which catalyze the oxidation of a wide range of phenolic and non-phenolic aromatic compounds in the presence or absence of a mediator. Till date, laccases have mostly been isolated from fungi and plants, whereas laccase from bacteria has not been well studied. Bacterial laccases have several unique properties that are not characteristics of fungal laccases such as stability at high temperature and high pH. Bacteria produce these enzymes either extracellularly or intracellularly and their activity is in a wide range of temperature and pH. It has application in pulp biobleaching, bioremediation, textile dye decolorization, pollutant degradation, biosensors, etc. Hence, comprehensive information including sources, production conditions, characterization, cloning and biotechnological applications is needed for the effective understanding and application of these enzymes at the industrial level. The present review provides exhaustive information of bacterial laccases reported till date.

  19. Bacterial overgrowth and methane production in children with encopresis.

    Science.gov (United States)

    Leiby, Alycia; Mehta, Devendra; Gopalareddy, Vani; Jackson-Walker, Susan; Horvath, Karoly

    2010-05-01

    To assess the prevalence of small intestinal bacterial overgrowth (SIBO) and methane production in children with encopresis. Radiographic fecal impaction (FI) scores were assessed in children with secondary, retentive encopresis and compared with the breath test results. Breath tests with hypoosmotic lactulose solution were performed in both the study patients (n = 50) and gastrointestinal control subjects (n = 39) groups. The FI scores were significantly higher in the patients with encopresis who were methane producers (P encopresis and 9 of 39 (23%) of control subjects (P = .06). Methane was produced in 56% of the patients with encopresis versus 23.1% of the control subjects in the gastrointestinal group (P encopresis had a higher prevalence of SIBO, elevated basal methane levels, and higher methane production. Methane production was associated with more severe colonic impaction. Further study is needed to determine whether methane production is a primary or secondary factor in the pathogenesis of SIBO and encopresis.

  20. Diversity of cuticular wax among Salix species and Populus species hybrids.

    Science.gov (United States)

    Cameron, Kimberly D; Teece, Mark A; Bevilacqua, Eddie; Smart, Lawrence B

    2002-08-01

    The leaf cuticular waxes of three Salix species and two Populus species hybrids, selected for their ability to produce high amounts of biomass, were characterized. Samples were extracted in CH(2)Cl(2) three times over the growing season. Low kV SEM was utilized to observe differences in the ultrastructure of leaf surfaces from each clone. Homologous series of wax components were classified into organic groups, and the variation in wax components due to clone, sample time, and their interaction was identified. All Salix species and Populus species hybrids showed differences in total wax load at each sampling period, whereas the pattern of wax deposition over time differed only between the Salix species. A strong positive relationship was identified between the entire homologous series of alcohols and total wax load in all clones. Similarly strong relationships were observed between fatty acids and total wax load as well as fatty acids and alcohols in two Salix species and one Populus species hybrid. One Salix species, S. dasyclados, also displayed a strong positive relationship between alcohols and alkanes. These data indicate that species grown under the same environmental conditions produce measurably different cuticular waxes and that regulation of wax production appears to be different in each species. The important roles cuticular waxes play in drought tolerance, pest, and pathogen resistance, as well as the ease of wax extraction and analysis, strongly suggest that the characteristics of the cuticular wax may prove to be useful selectable traits in a breeding program.

  1. Bacterial cellulose biosynthesis: diversity of operons, subunits, products and functions

    Science.gov (United States)

    Römling, Ute; Galperin, Michael Y.

    2015-01-01

    Summary Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits – which differ among various taxa – affect the enzymatic activity and product yield in vivo by modulating expression of biosynthesis apparatus, export of the nascent β-D-glucan polymer to the cell surface, and the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of the resulting biofilm, which is particularly important for interactions of bacteria with higher organisms that lead to rhizosphere colonization and modulate virulence of cellulose-producing bacterial pathogens inside and outside of host cells. Here we review the organization of four principal types of cellulose synthase operons found in various bacterial genomes, identify additional bcs genes that encode likely components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms formed by a variety of free-living and pathogenic bacteria and, for the latter, in the choice between acute infection and persistence in the host. PMID:26077867

  2. Smokeless tobacco products harbor diverse bacterial microbiota that differ across products and brands.

    Science.gov (United States)

    Smyth, Eoghan M; Kulkarni, Prachi; Claye, Emma; Stanfill, Stephen; Tyx, Robert; Maddox, Cynthia; Mongodin, Emmanuel F; Sapkota, Amy R

    2017-07-01

    Smokeless tobacco products contain numerous chemical compounds, including known human carcinogens. Other smokeless tobacco constituents, including bacteria, may also contribute to adverse health effects among smokeless tobacco users. However, there is a lack of data regarding the microbial constituents of smokeless tobacco. Our goal was to characterize the bacterial microbiota of different smokeless tobacco products and evaluate differences across product types and brands. DNA was extracted from 15 brands of smokeless tobacco products (including dry snuff, moist snuff, snus, and Swedish snus) and 6 handmade products (e.g., toombak) using an enzymatic and mechanical lysis approach. Bacterial community profiling was performed using PCR amplification of the V1-V2 hypervariable region of the 16S rRNA gene, followed by 454 pyrosequencing of the resulting amplicons and sequence analysis using the QIIME package. Total viable counts were also determined to estimate the number of viable bacteria present in each product. Average total viable counts ranged from 0 to 9.35 × 10 7  CFU g -1 . Analysis of the 16S rRNA gene sequences revealed high bacterial diversity across the majority of products tested: dry snuff products where characterized by the highest diversity indices compared to other products. The most dominant bacterial phyla across all products were Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. Significant differences in both bacterial community composition and in silico predicted gene content were observed between smokeless tobacco product types and between brands of specific smokeless tobacco products. These data are useful in order to comprehensively address potential health risks associated with the use of smokeless tobacco products.

  3. Development of a Parafin Wax deposition Unit for Fused Deposition Modelling (FDM)

    DEFF Research Database (Denmark)

    D'Angelo, Greta; Hansen, Hans Nørgaard; Pedersen, David Bue

    2014-01-01

    . This project illustrates the redesign of an extrusion unit for the deposition of paraffin wax in Fused Deposition Modelling (FDM) instead of the conventional polymeric materials. Among the benefits and brought by the use of paraffin wax in such system are: the possibility to make highly complex and precise...... parts to subsequently use in a Lost Wax Casting process, multi-material Additive Manufacturing and the use of wax as support material during the production of complicated parts. Moreover it is believed that including waxes among the materials usable in FDM would promote new ways of using and exploring...

  4. Production of bacterial cellulose and enzyme from waste fiber sludge

    Science.gov (United States)

    2013-01-01

    Background Bacterial cellulose (BC) is a highly crystalline and mechanically stable nanopolymer, which has excellent potential as a material in many novel applications, especially if it can be produced in large amounts from an inexpensive feedstock. Waste fiber sludge, a residue with little or no value, originates from pulp mills and lignocellulosic biorefineries. A high cellulose and low lignin content contributes to making the fiber sludge suitable for bioconversion, even without a thermochemical pretreatment step. In this study, the possibility to combine production of BC and hydrolytic enzymes from fiber sludge was investigated. The BC was characterized using field-emission scanning electron microscopy and X-ray diffraction analysis, and its mechanical properties were investigated. Results Bacterial cellulose and enzymes were produced through sequential fermentations with the bacterium Gluconacetobacter xylinus and the filamentous fungus Trichoderma reesei. Fiber sludges from sulfate (SAFS) and sulfite (SIFS) processes were hydrolyzed enzymatically without prior thermochemical pretreatment and the resulting hydrolysates were used for BC production. The highest volumetric yields of BC from SAFS and SIFS were 11 and 10 g/L (DW), respectively. The BC yield on initial sugar in hydrolysate-based medium reached 0.3 g/g after seven days of cultivation. The tensile strength of wet BC from hydrolysate medium was about 0.04 MPa compared to about 0.03 MPa for BC from a glucose-based reference medium, while the crystallinity was slightly lower for BC from hydrolysate cultures. The spent hydrolysates were used for production of cellulase with T. reesei. The cellulase activity (CMCase activity) in spent SAFS and SIFS hydrolysates reached 5.2 U/mL (87 nkat/mL), which was similar to the activity level obtained in a reference medium containing equal amounts of reducing sugar. Conclusions It was shown that waste fiber sludge is a suitable raw material for production of

  5. Bacterial and Fungal Proteolytic Enzymes: Production, Catalysis and Potential Applications.

    Science.gov (United States)

    da Silva, Ronivaldo Rodrigues

    2017-09-01

    Submerged and solid-state bioprocesses have been extensively explored worldwide and employed in a number of important studies dealing with microbial cultivation for the production of enzymes. The development of these production technologies has facilitated the generation of new enzyme-based products with applications in pharmaceuticals, food, bioactive peptides, and basic research studies, among others. The applicability of microorganisms in biotechnology is potentiated because of their various advantages, including large-scale production, short time of cultivation, and ease of handling. Currently, several studies are being conducted to search for new microbial peptidases with peculiar biochemical properties for industrial applications. Bioprospecting, being an important prerequisite for research and biotechnological development, is based on exploring the microbial diversity for enzyme production. Limited information is available on the production of specific proteolytic enzymes from bacterial and fungal species, especially on the subgroups threonine and glutamic peptidases, and the seventh catalytic type, nonhydrolytic asparagine peptide lyase. This gap in information motivated the present study about these unique biocatalysts. In this study, the biochemical and biotechnological aspects of the seven catalytic types of proteolytic enzymes, namely aspartyl, cysteine, serine, metallo, glutamic, and threonine peptidase, and asparagine peptide lyase, are summarized, with an emphasis on new studies, production, catalysis, and application of these enzymes.

  6. The Effect of Various Oral Hygiene Products on Bacterial Growth

    Science.gov (United States)

    Viswanath, S.; Aggrawal, A.; Vazirani, S.

    2017-12-01

    In this experiment, we tested the antimicrobial effectiveness of six different oral hygiene products. We used three natural cleansing products (coconut oil, sea salt, and baking soda), as well as three synthetic products, which were the Colgate toothpaste varieties of sensitivity, cavity protection, and whitening. We mixed water with each of the products to create a paste that could be uniformly applied to the surface of a disc. We then dipped the discs into the solutions and placed them in petri dishes that were pre-treated with bacterial cells. After 72 hours, we measured the area around the disc that was bacteria-free, which is known as the zone of inhibition. This experiment was repeated twice, with one petri dish per product for each trial, and two different types of agar. We were surprised to discover that almost all the products had no zone of inhibition, with bacteria growing throughout the petri dish, and to the disc. The only cleaning product that showed a significant antibacterial result was the Colgate sensitivity toothpaste. During the two trials, the sensitivity toothpaste had a zone of inhibition of 14.8 cm2 and 8.7 cm2, respectively. Coconut oil was the only other product to have a measurable zone of inhibition with an area of 0.3 cm2. We concluded that only the sensitivity toothpaste was effective in killing bacteria, perhaps due to its different hygienic goal of protecting the tooth's nerves. This toothpaste contains ingredients called potassium nitrate and strontium chloride, which blocks tubules in the dentin, the hard, bony tissue beneath the enamel. Sensitivity toothpaste strengthens the tooth, by blocking decaying substances such as oral bacteria (Knights, 2014).

  7. Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

    Energy Technology Data Exchange (ETDEWEB)

    Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.; Dohnalkova, Alice; Hu, Dehong; Lemke, Rachelle A.; Piotrowski, Jeff S.; Orr, Galya; Noguera, Daniel R.; Donohue, Timothy J.

    2017-05-23

    ABSTRACT

    Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation inRhodobacter sphaeroides. By screening anR. sphaeroidesTn5mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their total lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals.

    IMPORTANCEThis paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase

  8. Violacein: Properties and Production of a Versatile Bacterial Pigment

    Directory of Open Access Journals (Sweden)

    Seong Yeol Choi

    2015-01-01

    Full Text Available Violacein-producing bacteria, with their striking purple hues, have undoubtedly piqued the curiosity of scientists since their first discovery. The bisindole violacein is formed by the condensation of two tryptophan molecules through the action of five proteins. The genes required for its production, vioABCDE, and the regulatory mechanisms employed have been studied within a small number of violacein-producing strains. As a compound, violacein is known to have diverse biological activities, including being an anticancer agent and being an antibiotic against Staphylococcus aureus and other Gram-positive pathogens. Identifying the biological roles of this pigmented molecule is of particular interest, and understanding violacein’s function and mechanism of action has relevance to those unmasking any of its commercial or therapeutic benefits. Unfortunately, the production of violacein and its related derivatives is not easy and so various groups are also seeking to improve the fermentative yields of violacein through genetic engineering and synthetic biology. This review discusses the recent trends in the research and production of violacein by both natural and genetically modified bacterial strains.

  9. Using Natural Products to Treat Resistant and Persistent Bacterial Infections

    Science.gov (United States)

    Deering, Robert W.

    Antimicrobial resistance is a growing threat to human health both worldwide and in the United States. Most concerning is the emergence of multi-drug resistant (MDR) bacterial pathogens, especially the 'ESKAPE' pathogens for which treatment options are dwindling. To complicate the problem, approvals of antibiotic drugs are extremely low and many research and development efforts in the pharmaceutical industry have ceased, leaving little certainty that critical new antibiotics are nearing the clinic. New antibiotics are needed to continue treating these evolving infections. In addition to antibiotics, approaches that aim to inhibit or prevent antimicrobial resistance could be useful. Also, studies that improve our understanding of bacterial pathophysiology could lead to new therapies for infectious disease. Natural products, especially those from the microbial world, have been invaluable as resources for new antibacterial compounds and as insights into bacterial physiology. The goal of this dissertation is to find new ways to treat resistant bacterial infections and learn more about the pathophysiology of these bacteria. Investigations of natural products to find molecules able to be used as new antibiotics or to modulate resistance and other parts of bacterial physiology are crucial aspects of the included studies. The first included study, which is reported in chapter two, details a chemical investigation of a marine Pseudoalteromonas sp. Purification efforts of the microbial metabolites were guided by testing against a resistance nodulation of cell division model of efflux pumps expressed in E. coli. These pumps play an important role in the resistance of MDR Gram negative pathogens such as Pseudomonas aeruginosa and Enterobacteriaceae. Through this process, 3,4-dibromopyrrole-2,5-dione was identified as a potent inhibitor of the RND efflux pumps and showed synergistic effects against the E. coli strain with common antibiotics including fluoroquinolones, beta

  10. Phototransformation of the herbicide sulcotrione on maize cuticular wax.

    Science.gov (United States)

    Ter Halle, Alexandra; Drncova, Daniela; Richard, Claire

    2006-05-01

    Vegetation plays a key role in environmental cycling and the fate of many organic pollutants. This is especially the case for pesticides because plant leaves are their first reaction environment after application. It is commonly accepted that photochemical reactions of pollutants on plants predominantly take place in the cuticular wax coating of the leaves. Thus, we used films made of either cuticular wax extracted from maize or carnauba gray wax as a model support. Under simulated sunlight irradiation, sulcotrione (a new class of triketone herbicides) sorbed on cuticular wax films was photolyzed and mainly underwent an intramolecular cyclization. The photoproduct is a chromone derivative which was isolated and fully characterized. It is reported for the first time as a sulcotrione degradation product. The photoreactivity of formulated sulcotrione at the surface of cuticular waxes was investigated too. It photodegraded more rapidly than nonformulated sulcotrione. This study also shows that the rate of sulcotrione photolysis was much faster than the rate of penetration into the wax; photolysis should be, thus, a relevant process in real conditions.

  11. Characterizing bacterial communities in paper production-troublemakers revealed.

    Science.gov (United States)

    Zumsteg, Anita; Urwyler, Simon K; Glaubitz, Joachim

    2017-08-01

    Biofilm formation is a major cause of reduced paper quality and increased down time during paper manufacturing. This study uses Illumina next-generation sequencing to identify the microbial populations causing quality issues due to their presence in biofilms and slimes. The paper defects investigated contained traces of the films and/or slime of mainly two genera, Tepidimonas and Chryseobacterium. The Tepidimonas spp. found contributed on average 68% to the total bacterial population. Both genera have been described previously to be associated with biofilms in paper mills. There was indication that Tepidimonas spp. were present as compact biofilm in the head box of one paper machine and was filtered out by the paper web during production. On the other hand Tepidimonas spp. were also present to a large extent in the press and white waters of two nonproblematic paper machines. Therefore, the mere presence of a known biofilm producer alone is not sufficient to cause slimes and therefore paper defects and other critical factors are additionally at play. For instance, we identified Acidovorax sp., which is an early colonizer of paper machines, exhibiting the ability to form extracellular DNA matrices for attachment and biofilm formation. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. Cost-effective production of bacterial cellulose using acidic food industry by-products.

    Science.gov (United States)

    Revin, Victor; Liyaskina, Elena; Nazarkina, Maria; Bogatyreva, Alena; Shchankin, Mikhail

    2018-03-13

    To reduce the cost of obtaining bacterial cellulose, acidic by-products of the alcohol and dairy industries were used without any pretreatment or addition of other nitrogen sources. Studies have shown that the greatest accumulation of bacterial cellulose (6.19g/L) occurs on wheat thin stillage for 3 days of cultivation under dynamic conditions, which is almost 3 times higher than on standard Hestrin and Schramm medium (2.14g/L). The use of whey as a nutrient medium makes it possible to obtain 5.45g/L bacterial cellulose under similar conditions of cultivation. It is established that the pH of the medium during the growth of Gluconacetobacter sucrofermentans B-11267 depends on the feedstock used and its initial value. By culturing the bacterium on thin stillage and whey, there is a decrease in the acidity of the waste. It is shown that the infrared spectra of bacterial cellulose obtained in a variety of environments have a similar character, but we found differences in the micromorphology and crystallinity of the resulting biopolymer. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  13. Simple Synthesis Hydrogenated Castor Oil Fatty Amide Wax and Its Coating Characterization.

    Science.gov (United States)

    Yu, Xiuzhu; Wang, Ning; Zhang, Rui; Zhao, Zhong

    2017-07-01

    A simple method for incorporating amine groups in hydrogenated castor oil (HCO) to produce wax for beeswax or carnauba wax substitution in packaging and coating was developed. From the conversion rate of the products, HCO was reacted with ethanolamine at 150°C for 5 h, and the molar ratio of HCO and ethanolamine was 1:4. The hardness of the final product was seven times higher than that of beeswax, the cohesiveness of the final product was 1.3 times higher than that of beeswax and approximately one half of that of carnauba wax, and the melting point of the final product is 98°C. The Fourier transform Infrared spectroscopy showed that the amide groups were incorporated to form the amide products. In coating application, the results showed that the force of the final product coating cardboard was higher than that of beeswax and paraffin wax and less than that of carnauba wax. After 24 h soaking, the compression forces were decreased. HCO fatty acid wax can be an alternative wax for carnauba wax and beeswax in coating applications.

  14. Resistance of Aerosolized Bacterial Viruses to Four Germicidal Products.

    Directory of Open Access Journals (Sweden)

    Nathalie Turgeon

    Full Text Available Viral diseases can spread through a variety of routes including aerosols. Yet, limited data are available on the efficacy of aerosolized chemicals to reduce viral loads in the air. Bacteriophages (phages are often used as surrogates for hazardous viruses in aerosol studies because they are inexpensive, easy to handle, and safe for laboratory workers. Moreover, several of these bacterial viruses display physical characteristics similar to pathogenic human and animal viruses, like morphological size, type of nucleic acids, capsid morphology, and the presence of an envelope. In this study, the efficacy of four chemicals was evaluated on four airborne phages at two different relative humidity levels. Non-tailed bacteriophages MS2 (single-stranded RNA, ϕ6 (double-stranded RNA, enveloped, PR772 (double-stranded DNA, and ϕX174 (single-stranded DNA were first aerosolized in a 55L rotative environmental chamber at 19°C with 25% and 50% relative humidity. Then, hydrogen peroxide, Eugenol (phenylpropene used in commercial perfumes and flavorings, Mist® (automobile disinfectant containing Triethylene glycol, and Pledge® (multisurface disinfectant containing Isopropanol, n-Alkyl Dimethyl Benzyl Amonium Chlorides, and n-Alkyl Dimethyl Ethylbenzyl Ammonium Chloride were nebulized with the phages using a separate nebulizer. Aerosols were maintained in suspension during 10 minutes, 1 hour, and 2 hours. Viral aerosols were sampled using an SKC BioSampler and samples were analyzed using qPCR and plaque assays. The resistance levels of the four phages varied depending on the relative humidity (RH and germicidal products tested. Phage MS2 was the most stable airborne virus under the environmental conditions tested while phage PR772 was the least stable. Pledge® and Eugenol reduced the infectivity of all airborne phages tested. At 25% RH, Pledge® and Eugenol were more effective at reducing infectivity of RNA phages ϕ6 and MS2. At 50% RH, Pledge® was the most

  15. Seasonal and spatial variation of bacterial production and abundance in the northern Levantine Sea

    Directory of Open Access Journals (Sweden)

    N. YUCEL

    2017-03-01

    Full Text Available Spatial and temporal heterogeneity in bacterial production and abundance in relation to ambient bio-physicochemical parameters has been investigated in the Levantine Sea. Five stations with different trophic states in an area extending from highly eutrophic Mersin bay to the mesotrophic Rhodes gyre area including the oligotrophic offshore waters were sampled four times. Integrated bacterial production varied between 6.1 and 90.3 µg C m-2 d-1 with higher rates occurring during September 2012 in offshore waters. Bacterial abundance ranged between 0.18 and 7.3 x 105 cells ml-1 within the euphotic zone and was generally higher up to 100 meters throughout the study period. In offshore waters, bacterial production (0.401 to 0.050 µg C m-3 d-1, abundance (4.5 to 1.6 x 105 cells ml-1 and depth of the productive layer decreased from 150 to 75 meters westward along the transect. Although the highest abundance was observed in July 2012 in offshore waters, the highest activity was measured in September 2012. These results indicated that the temperature played a key role in regulating bacterial abundance and production in the area. High chlorophyll concentrations in March did not correspond to high bacterial abundance and production at the same time. Increase in dissolved organic carbon content following spring phytoplankton bloom and the increase in temperature in the mean time might have enhanced the bacterial activity towards summer.

  16. Production of bacterial protein from sugar cane bagasse pith

    Energy Technology Data Exchange (ETDEWEB)

    Molina, O E; Callieri, D A.S.; Perotti de Galvez, N

    1980-01-01

    Bacterial protein was produced during the fermentation of sugar cane bagasse pith (BP) by a mixture of cellulolytic bacteria, one of them being a species of Cellulomonas. If the BP were treated with 1% NaOH prior to fermentation, the liquor could be used twice more without affecting the yield of bacterial protein. After that, the liquor became too dark and impaired the subsequent washing of BP. If the concentration of N (as NaN0/sub 3/) in the fermentation medium were raised, the conversion factor to protein was lowered, but the amount of protein formed per L per h and the ratio of protein to BP became higher. The evolution of pH, the dry matter content, cellulolytic activity, and protein yield were all affected by the type of N source used. The yield of bacterial protein can probably be increased by automatically controlling the pH and dissolved O levels of the culture.

  17. Comparison of Heterotrophic Bacterial Production-Rates in Early Spring in the Turbid Estuaries of the Scheldt and the Elbe

    NARCIS (Netherlands)

    Goosen, N.K.; Van Rijswijk, P.; Brockmann, U.

    1995-01-01

    In spring bacterial production rates were estimated by tritiated thymidine incorporation in the turbid estuaries of the rivers Scheldt and Elbe. Bacterial production rates in the Scheldt were 5 times higher than in the Elbe. In the Scheldt bacterial production rates correlated better with the DOC

  18. 9 CFR 113.100 - General requirements for inactivated bacterial products.

    Science.gov (United States)

    2010-01-01

    ... instances, the guinea pig safety test provided in § 113.38 shall be conducted in place of the mouse safety... Outline of Production, an inactivated bacterial product shall meet the applicable requirements in this... in poultry as defined in the specific Standard Requirement or Outline of Production for the product...

  19. THE EFFECT OF PROBIOTIC BACTERIAL CONCENTRATE "IMMUNOLAKT" ON BAKERY PRODUCTS QUALITY

    Directory of Open Access Journals (Sweden)

    E. V. Belokurova

    2015-01-01

    Full Text Available Nowadays the development of new food products is paid much attention in the food industry. These include also bakery products with lactic starter cultures which contain live microorganisms, vitamins of group B: B1, B2, B6, B12, B9, vitamins A, C, E, folic acid. In this article the technological aspects of the probiotic bacterial concentrate "Immunolakt" in the manufacture of bakery products were studied. The experimental product was developed on the basis of traditional technology taking into account the properties of the introduced additives to correct some technological parameters. The research resulted in the development of technology of bakery products with the introduction of probiotic bacterial concentrate "Immunolakt.". To develop the recipes of dough products probiotic bacterial concentrates "Immunolakt" at 20, 40, 60, 80 and 100% was used instead of a part of yeast in the recipe. Comparative studies of the microstructure of bakery products crumb with the addition of probiotic bacterial concentrate "Immunolakt" and the reference sample were carried out. The content of the probiotic bacterial concentrate of 40% and 60% promoted the formation of a more uniform pore structure and reduction in the number ruptures along their perimeter. Safety indicators of reference and test samples were determined. The number of bacteria of reference and experimental samples of bakery products are in the normal range. The number of mesophilic aerobic and facultative anaerobic bacteria in the test samples is less than in the reference one. Qualimetric evaluation of the quality of finished products was carried out. The developed products are of high organoleptic quality indexes, they are physically and chemically stable, with enhanced nutritional value. Products with the introduction of probiotic bacterial concentrate allow to expand the range of functional orientation bakery products. The use of probiotic bacterial concentrates allows to adjust the course of

  20. Content of Wax during Dewaxing Process: Adopting a DOE Method

    Directory of Open Access Journals (Sweden)

    Mohammad Hosein Eghbali

    2013-01-01

    Full Text Available The oil content of the wax produced in a dewaxing process is the key economic parameter that should be reduced as much as possible. Some factors such as the type of solvents, cooling rate, temperature, and solvent to oil ratio influence the dewaxing process. Due to the fact that crude oil differs from place to place and since the operational conditions for wax extraction vary for different types of crude oil, the objective of this work is to study the operational conditions for wax production from an Iranian raffinate sample used in Sepahan Oil Company. All the experiments are conducted based on a design of experiment (DOE technique for minimizing the oil content of the wax produced. The effects of five factors have been determined quantitatively and appropriate levels are suggested for reducing the oil content. The results show that the solvent ratio, solvent composition, and cooling rate play the most important role in minimizing the oil content of the produced wax.

  1. Comparison of protease production from newly isolated bacterial ...

    African Journals Online (AJOL)

    Nasir

    2016-10-12

    Oct 12, 2016 ... Protease has gained a very important position in many industries such as food, pharmaceutical, chemical and leather industries. In this research, protease was obtained from bacteria. The bacterial strain was obtained from soil which was collected from different areas of Lahore, Pakistan. Fermentation ...

  2. Bacterial Cellulose Production from Beet Molasses | Keshk | African ...

    African Journals Online (AJOL)

    The yield of the bacterial cellulose (BC) produced from beet molasses was higher than that using glucose as a sole carbon source. The structure of BC produced in presence of beet molasses was studied using IR spectroscopy and X-ray diffractometry. IR spectra show the relative absorbance of CO- C ether linkage (at 1120 ...

  3. Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil.

    Science.gov (United States)

    Iven, Tim; Hornung, Ellen; Heilmann, Mareike; Feussner, Ivo

    2016-01-01

    Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  4. Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma: a nested case-control study.

    NARCIS (Netherlands)

    Fedirko, Veronika; Tran, Hao Quang; Gewirtz, Andrew T; Stepien, Magdalena; Trichopoulou, Antonia; Aleksandrova, Krasimira; Olsen, Anja; Tjønneland, Anne; Overvad, Kim; Carbonnel, Franck; Boutron-Ruault, Marie-Christine; Severi, Gianluca; Kühn, Tilman; Kaaks, Rudolf; Boeing, Heiner; Bamia, Christina; Lagiou, Pagona; Grioni, Sara; Panico, Salvatore; Palli, Domenico; Tumino, Rosario; Naccarati, Alessio; Peeters, Petra H; Bueno-de-Mesquita, H B; Weiderpass, Elisabete; Castaño, José María Huerta; Barricarte, Aurelio; Sánchez, María-José; Dorronsoro, Miren; Quirós, J Ramón; Agudo, Antonio; Sjöberg, Klas; Ohlsson, Bodil; Hemmingsson, Oskar; Werner, Mårten; Bradbury, Kathryn E; Khaw, Kay-Tee; Wareham, Nick; Tsilidis, Konstantinos K; Aune, Dagfinn; Scalbert, Augustin; Romieu, Isabelle; Riboli, Elio; Jenab, Mazda

    2017-01-01

    Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking.

  5. Applications of micro-SAXS/WAXS to study polymer fibers

    International Nuclear Information System (INIS)

    Riekel, C.

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 μm. WAXS experiments can be performed down to about 2 μm and in exceptional cases down to 0.1 μm beam size. The instrumental possibilities are demonstrated for the production line of spider silk

  6. Applications of micro-SAXS/WAXS to study polymer fibers

    Energy Technology Data Exchange (ETDEWEB)

    Riekel, C. E-mail: riekel@esrf.fr

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 {mu}m. WAXS experiments can be performed down to about 2 {mu}m and in exceptional cases down to 0.1 {mu}m beam size. The instrumental possibilities are demonstrated for the production line of spider silk.

  7. Applications of micro-SAXS/WAXS to study polymer fibers

    Science.gov (United States)

    Riekel, C.

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 μm. WAXS experiments can be performed down to about 2 μm and in exceptional cases down to 0.1 μm beam size. The instrumental possibilities are demonstrated for the production line of spider silk.

  8. Seasonal and spatial patterns of heterotrophic bacterial production, respiration, and biomass in the subarctic NE Pacific

    Science.gov (United States)

    Sherry, Nelson D.; Boyd, Philip W.; Sugimoto, Kugako; Harrison, Paul J.

    1999-11-01

    Heterotrophic bacterial biomass, production, and respiration rates were measured during winter, spring, and summer in the subarctic NE Pacific from September 1995 to June 1997. Sampling took place on six cruises at five hydrographic stations along the east/west line-P transect from slope waters at P4 (1200 m depth) to the open-ocean waters at Ocean Station Papa (OSP) (4250 m depth). Interannual variability was small relative to seasonal and spatial variability. Biomass, derived from cell counts (assuming 20 fg C cell -1), was ca. 12 μg C l -1 in the winter and increased to 20-35 μg C l -1 in the spring and summer all along line-P. Bacterial production from [ 3H]-thymidine and [ 14C]-leucine incorporation rates was lowest in the winter (ca. 0.5 μg C l -1 d -1) with little spatial variability. Production increased 10-fold in spring at P4 (to ca. 4.5 μg C l -1 d -1). In contrast, only a 2-fold increase in bacterial production was observed over this period at the more oceanic stations. Rates of production in late summer were highest over the annual cycle at all stations ranging from ca. 6 at P4 to ca. 2 μg C l -1 d -1 at OSP. Bacterial (rates increased >10-fold to ca. 100 μg C l -1 d -1 at P4 in the summer, but, interestingly, did not increase from spring to summer at the more oceanic stations. Thus bacterial growth efficiency, defined as production/(production+respiration), decreased in the spring westwards from the slope waters (P4) to the open-ocean (OSP), but increased westwards in the summer. Bacterial production was highly correlated with temperature at OSP ( r2=0.88) and less so at P4 ( r2=0.50). The observed temporal and spatial trends presented in this study suggest that seasonal changes in bacterial biomass were greatly affected by changes in loss processes, that bacterial biomass is regulated by different processes than bacterial production, and that bacterial production alone, without respiration measurements, is not a robust proxy for bacterial

  9. Expert Opinion on Three Phage Therapy Related Topics: Bacterial Phage Resistance, Phage Training and Prophages in Bacterial Production Strains

    Directory of Open Access Journals (Sweden)

    Christine Rohde

    2018-04-01

    Full Text Available Phage therapy is increasingly put forward as a “new” potential tool in the fight against antibiotic resistant infections. During the “Centennial Celebration of Bacteriophage Research” conference in Tbilisi, Georgia on 26–29 June 2017, an international group of phage researchers committed to elaborate an expert opinion on three contentious phage therapy related issues that are hampering clinical progress in the field of phage therapy. This paper explores and discusses bacterial phage resistance, phage training and the presence of prophages in bacterial production strains while reviewing relevant research findings and experiences. Our purpose is to inform phage therapy stakeholders such as policy makers, officials of the competent authorities for medicines, phage researchers and phage producers, and members of the pharmaceutical industry. This brief also points out potential avenues for future phage therapy research and development as it specifically addresses those overarching questions that currently call for attention whenever phages go into purification processes for application.

  10. Epicuticular wax on stomata of damaged silver fir trees (Abies alba Mili.

    Directory of Open Access Journals (Sweden)

    Tomislav Bačić

    2011-01-01

    Full Text Available Condition of epistomatal wax on the abaxial surface of the current and previous-year needles of damaged silver fir trees (Abies alba Mill., both from the polluted Risnjak and "clean" Donja Dobra sites in Gorski Kotar region, both influenced by pollutants coming from Europe, during two years, three times a year, were examined with Scanning Electron Microscope. In the course of time the wax tubules on the epistomatal rims of stomata in polluted, but also in "clean" needles surface, become fused and agglomerated rapidly to various extents of morphologically different types of amorphous wax crusts, primarily compact and particulate ones. This process begins very early, especially in polluted Risnjak site, and may be interpreted as a possible result of air pollution. However, the recrystalization, or production of new tubules, also appears relatively quickly in mostly cases. Quantitative estimations indicate a very large total amount of amorphous wax crusts in the current-year needles, and a very high percentage of the same wax in previous-year needles. Amorphous wax crusts cover stomatal pores, as well as the rims, disturbing the normal gas exchange. Statistically there is a signicant tendency of increase in wax degradation in the needles of the polluted site in comparison with those of the unpolluted one, but there is an insignificant wax degradation among the needles of damaged trees within each site. These results confirmed most of the research done in our preliminary report.

  11. Effects of Au/Fe and Fe nanoparticles on Serratia bacterial growth and production of biosurfactant

    International Nuclear Information System (INIS)

    Liu, Jia; Vipulanandan, Cumaraswamy

    2013-01-01

    The overall objective of this study was to compare the effects of Au/Fe and Fe nanoparticles on the growth and performance of Serratia Jl0300. The nanoparticle effect was quantified not only by the bacterial growth on agar plate after 1 hour interaction with the nanoparticles, but also by its production of a biosurfactant from used vegetable oil. The nanoparticles were prepared using the foam method. The concentrations of the nanoparticles used for the bacterial interaction study were varied from 1 mg/L to 1 g/L. The test results showed that the effect of nanoparticles on the bacterial growth and biosurfactant production varied with nanoparticle type, concentrations, and interaction time with the bacteria. Au/Fe nanoparticles didn't show toxicity to Serratia after short time (1 h) exposure, while during 8 days fermentation Au/Fe nanoparticles inhibited the growth of Serratia as well as the biosurfactant production when the concentration of the nanoparticles was higher than 10 mg/L. Fe nanoparticles showed inhibition effects to bacterial growth both after short time and long time interaction with Serratia, as well as to biosurfactant production when its concentration was higher than 100 mg/L. Based on the trends observed in this study, analytical models have been developed to predict the bacterial growth and biosurfactant production with varying concentrations of nanoparticles. - Highlights: • Modeled the effect of nanoparticles on the bacterial growth and biosurfactant production. • Effects of Au/Fe nonoparticles on Serratia Bacterial Growth and Production of Biosurfactant. • Scanning Electron Micrograph of bacteria-nanoparticles interaction

  12. Glycerol Monolaurate Inhibits Lipase Production by Clinical Ocular Isolates Without Affecting Bacterial Cell Viability.

    Science.gov (United States)

    Flanagan, Judith Louise; Khandekar, Neeta; Zhu, Hua; Watanabe, Keizo; Markoulli, Maria; Flanagan, John Terence; Papas, Eric

    2016-02-01

    We sought to determine the relative lipase production of a range of ocular bacterial isolates and to assess the efficacy of glycerol monolaurate (GML) in inhibiting this lipase production in high lipase-producing bacteria without affecting bacterial cell growth. Staphylococcus aureus,Staphylococcus epidermidis,Propionibacterium acnes, and Corynebacterium spp. were inoculated at a density of 10(6)/mL in varying concentrations of GML up to 25 μg/mL for 24 hours at 37 °C with constant shaking. Bacterial suspensions were centrifuged, bacterial cell density was determined, and production of bacterial lipase was quantified using a commercial lipase assay kit. Staphylococcus spp. produced high levels of lipase activity compared with P. acnes and Corynebacterium spp. GML inhibited lipase production by Staphylococcal spp. in a dose-dependent manner, with S. epidermidis lipase production consistently more sensitive to GML than S. aureus. Glycerol monolaurate showed significant (P < 0.05) lipase inhibition above concentrations of 15 μg/mL in S. aureus and was not cytotoxic up to 25 μg/mL. For S. epidermidis, GML showed significant (P < 0.05) lipase inhibition above 7.5 μg/mL. Lipase activity varied between species and between strains. Staphylococcal spp. produced higher lipase activity compared with P. acnes and Corynebacterium spp. Glycerol monolaurate inhibited lipase production by S. aureus and S. epidermidis at concentrations that did not adversely affect bacterial cell growth. GML can be used to inhibit ocular bacterial lipase production without proving detrimental to commensal bacteria viability.

  13. Effects of Au/Fe and Fe nanoparticles on Serratia bacterial growth and production of biosurfactant

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jia; Vipulanandan, Cumaraswamy, E-mail: cvipulanandan@uh.edu

    2013-10-15

    The overall objective of this study was to compare the effects of Au/Fe and Fe nanoparticles on the growth and performance of Serratia Jl0300. The nanoparticle effect was quantified not only by the bacterial growth on agar plate after 1 hour interaction with the nanoparticles, but also by its production of a biosurfactant from used vegetable oil. The nanoparticles were prepared using the foam method. The concentrations of the nanoparticles used for the bacterial interaction study were varied from 1 mg/L to 1 g/L. The test results showed that the effect of nanoparticles on the bacterial growth and biosurfactant production varied with nanoparticle type, concentrations, and interaction time with the bacteria. Au/Fe nanoparticles didn't show toxicity to Serratia after short time (1 h) exposure, while during 8 days fermentation Au/Fe nanoparticles inhibited the growth of Serratia as well as the biosurfactant production when the concentration of the nanoparticles was higher than 10 mg/L. Fe nanoparticles showed inhibition effects to bacterial growth both after short time and long time interaction with Serratia, as well as to biosurfactant production when its concentration was higher than 100 mg/L. Based on the trends observed in this study, analytical models have been developed to predict the bacterial growth and biosurfactant production with varying concentrations of nanoparticles. - Highlights: • Modeled the effect of nanoparticles on the bacterial growth and biosurfactant production. • Effects of Au/Fe nonoparticles on Serratia Bacterial Growth and Production of Biosurfactant. • Scanning Electron Micrograph of bacteria-nanoparticles interaction.

  14. 21 CFR 186.1555 - Japan wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Japan wax. 186.1555 Section 186.1555 Food and Drugs... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan...

  15. Comparison of Bacterial Cellulose Production among Different Strains and Fermented Media

    Directory of Open Access Journals (Sweden)

    Maryam Jalili Tabaii

    2015-12-01

    Full Text Available The effect of different carbon sources on bacterial cellulose production by Gluconacetobacter xylinus (PTCC 1734 and two newly isolated strains (from vinegar under static culture conditions was studied. The production of bacterial cellulose was examined in modified Hestrin-Shramm medium by replacing D-glucose with other carbon sources. The results showed that the yield and characteristics of bacterial cellulose were influenced by the type of carbon source. Glycerol gave the highest yield in all of the studied strains (6%, 9.7% and 3.8% for S, A2 strain and Gluconacetobacter xylinus (PTCC 1734, respectively. The maximum dry bacterial cellulose weight in the glycerol containing medium is due to A2 strain (1.9 g l-1 in comparison to Gluconacetobacter xylinus as reference strain (0.76 g l-1. Although all of the studied strains were in Gluconacetobacter family, each used different sugars for maximum production after glycerol (mannitol and fructose for two newly isolated strains and glucose for Gluconacetobacter xylinus. The maximum moisture content was observed when sucrose and food-grade sucrose were used as carbon source. Contrary to expectations, while the maximum thickness of bacterial cellulose membrane was attained when glycerol was used, bacterial cellulose from glycerol had less moisture content than the others. The oxidized cellulose showed antibacterial activities, which makes it as a good candidate for food-preservatives.

  16. Regulation of annual variation in heterotrophic bacterial production in the Schelde estuary (SW Netherlands)

    NARCIS (Netherlands)

    Goosen, N.K.; Van Rijswijk, P.; Kromkamp, J.C.; Peene, J.

    1997-01-01

    Heterotrophic bacterioplankton production (H-3-thymidine incorporation rate) and abundance in the surface water of the Schelde estuary (The Netherlands) were studied during an annual cycle in 1991 along the salinity gradient (0.8 to 33 psu). Bacterial production and numbers increased from the lower

  17. Physical properties of beeswax, sunflower wax, and candelilla wax mixtures and organogels

    Science.gov (United States)

    There is increased interest in natural waxes as alternatives to partially hydrogenated oils and saturated fats as oil structuring agents. Using relatively low concentrations (0.5-5%), natural waxes are able to form crystalline networks, or organogels, which bind liquid oil. Each natural wax is uniqu...

  18. Surfactants from petroleum paraffin wax

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, T.M.; Hussein, M.H.; El Sayed, A.S.

    Paraffin wax from Egyptian petroleum was purified and then oxidized to fatty acids which were esterified to form their methyl esters, fractionated and then hydrolysed. The obtained fatty acids were converted into the corresponding primary amines which were converted with ethylene oxide to form nonionic surfactants. The prepared primary amines were also converted into tertiary amines and then converted into cationic surfactants through condensation with benzyl chloride or 1-chloromethylnaphthalene. Also, amine oxide surfactants were prepared by oxidation of the tertiary amines with hydrogen peroxide. The surface active properties of all the prepared surfactants were determined, and the effect of their chemical structure on the surfactant properties are discussed in this paper.

  19. Bacterial community dynamics and product distribution during pH-adjusted fermentation of vegetable wastes.

    Science.gov (United States)

    Ye, N-F; Lü, F; Shao, L-M; Godon, J-J; He, P-J

    2007-10-01

    To estimate the effect of pH on the structures of bacterial community during fermentation of vegetable wastes and to investigate the relationship between bacterial community dynamics and product distribution. The bacterial communities in five batch tests controlled at different pH values [uncontrolled (about pH 4), 5, 6, 7 and 8] were monitored by denaturing gradient gel electrophoresis (DGGE) and single-strand conformation polymorphism (SSCP). The two fingerprinting methods provided consistent results and principal component analysis indicated a close similarity of bacterial community at pH 7 and 8 in addition to those at pH 4-6. This clustering also corresponded to dominant metabolic pathway. Thus, pH 7-8 shifted from alcohol-forming to acid-forming, especially butyric acid, whereas both alcohol-forming and acid-forming dominated at pH 5-6, and at pH 4, fermentation was inhibited. Shannon-weaver index was calculated to analyse the DGGE profiles, which revealed that the bacterial diversities at pH 7 and 8 were the highest while those at pH 5 and 4 (uncontrolled) were the lowest. According to sequencing results of the bands excised from DGGE gels, lactic acid bacteria and Clostridium sp. were predominant at all pH values, but varieties in species were observed as pH changed and time prolonged. The bacterial community during fermentation was materially influenced by pH and the diverse product distribution was related to the shift of different bacterial population. The study reveals that the impact of pH on fermentation product distribution is implemented primarily by changes of bacterial community. It also provides information about the comparison of two fingerprinting methods, DGGE and SSCP.

  20. Recent developments in the production and applications of bacterial cellulose fibers and nanocrystals.

    Science.gov (United States)

    Reiniati, Isabela; Hrymak, Andrew N; Margaritis, Argyrios

    2017-06-01

    Cellulosic nanomaterials provide a novel and sustainable platform for the production of high performance materials enabled by nanotechnology. Bacterial cellulose (BC) is a highly crystalline material and contains pure cellulose without lignin and hemicellulose. BC offers an opportunity to provide control of the products' properties in-situ, via specific BC production methods and culture conditions. The BC potential in advanced material applications are hindered by a limited knowledge of optimal BC production conditions, efficient process scale-up, separation methods, and purification methods. There is a growing body of work on the production of bacterial cellulose nanocrystals (BCNs) from BC fibers. However, there is limited information regarding the effect of BC fibers' characteristics on the production of nanocrystals. This review describes developments in BC and BCNs production methods and factors affecting their yield and physical characteristics.

  1. Method for Bacterial Growth and Ammonia Production and Effect of Inhibitory Substances in Disposable Absorbent Hygiene Products.

    Science.gov (United States)

    Forsgren-Brusk, Ulla; Yhlen, Birgitta; Blomqvist, Marie; Larsson, Peter

    The purpose of this study was to evaluate a pragmatic laboratory method to provide a technique for developing incontinence products better able to reduce malodor when used in the clinical setting. Bacterial growth and bacterially formed ammonia in disposable absorbent incontinence products was measured by adding synthetic urine inoculated with bacteria to test samples cut from the crotch area of the product. The inhibitory effect's of low pH (4.5 and 4.9) and 3 antimicrobial substances-chlorhexidine, polyhexamethylene biguanide (PHMB), and thymol-at 2 concentrations each, were studied. From the initial inocula of 3.3 log colony-forming units per milliliter (cfu/mL) at baseline, the bacterial growth of the references increased to 5.0 to 6.0 log cfu/mL at 6 hours for Escherichia coli, Proteus mirabilis, and Enterococcus faecalis. At 12 hours there was a further increase to 7.0 to 8.9 log cfu/mL. Adjusting the pH of the superabsorbent in the incontinence product from 6.0 to pH 4.5 and pH 4.9 significantly (P disposable absorbent products to inhibit bacterial growth and ammonia production. This technique, we describe, provides a pragmatic method for assessing the odor-inhibiting capacity of specific incontinence products.

  2. Estimating bacterial production in marine waters from the simultaneous incorporation of thymidine and leucine.

    Science.gov (United States)

    Chin-Leo, G; Kirchman, D L

    1988-08-01

    We examined the simultaneous incorporation of [H]thymidine and [C]leucine to obtain two independent indices of bacterial production (DNA and protein syntheses) in a single incubation. Incorporation rates of leucine estimated by the dual-label method were generally higher than those obtained by the single-label method, but the differences were small (dual/single = 1.1 +/- 0.2 [mean +/- standard deviation]) and were probably due to the presence of labeled leucyl-tRNA in the cold trichloroacetic acid-insoluble fraction. There were no significant differences in thymidine incorporation between dual- and single-label incubations (dual/ single = 1.03 +/- 0.13). Addition of the two substrates in relatively large amounts (25 nM) did not apparently increase bacterial activity during short incubations (leucine incorporation rates covaried over depth profiles of the Chesapeake Bay. Estimates of bacterial production based on thymidine and leucine differed by less than 25%. Although the need for appropriate conversion factors has not been eliminated, the dual-label approach can be used to examine the variation in bacterial production while ensuring that the observed variation in incorporation rates is due to real changes in bacterial production rather than changes in conversion factors or introduction of other artifacts.

  3. Measurement of the incorporation rates of four amino acids into proteins for estimating bacterial production.

    Science.gov (United States)

    Servais, P

    1995-03-01

    In aquatic ecosystems, [(3)H]thymidine incorporation into bacterial DNA and [(3)H]leucine incorporation into proteins are usually used to estimate bacterial production. The incorporation rates of four amino acids (leucine, tyrosine, lysine, alanine) into proteins of bacteria were measured in parallel on natural freshwater samples from the basin of the river Meuse (Belgium). Comparison of the incorporation into proteins and into the total macromolecular fraction showed that these different amino acids were incorporated at more than 90% into proteins. From incorporation measurements at four subsaturated concentrations (range, 2-77 nm), the maximum incorporation rates were determined. Strong correlations (r > 0.91 for all the calculated correlations) were found between the maximum incorporation rates of the different tested amino acids over a range of two orders of magnitude of bacterial activity. Bacterial production estimates were calculated using theoretical and experimental conversion factors. The productions calculated from the incorporation rates of the four amino acids were in good concordance, especially when the experimental conversion factors were used (slope range, 0.91-1.11, and r > 0.91). This study suggests that the incorporation of various amino acids into proteins can be used to estimate bacterial production.

  4. The regulation of bacterial production in the Chesapeake Bay

    International Nuclear Information System (INIS)

    Chin-Leo, G.

    1988-01-01

    In this study, the possibility that periods when the rates of macromolecule syntheses become uncoupled occur in natural assemblages of bacteria was examined by comparing rates of bacterial DNA and protein synthesis. A dual-label method which measures incorporation rates of [ 3 H]thymidine (TdR) into macromolecules (DNA) and of [ 14 C]leucine (Leu) into protein was developed to facilitate simultaneous estimation of these cellular activities in a single incubation. Under controlled conditions, changes in rates of Leu incorporation preceded fluctuations in TdR incorporation and the Leu:TdR ratio varied prior to shifts in growth rate indicating the uncoupling of protein and DNA synthesis which occurs during unbalanced growth. The delay between this uncoupling and a change in growth rate was always shorter than the generation time. In Chesapeake Bay, during October 1986, the Leu:TdR ratio was quite constant over a diel cycle and with depth, but during July 1987, the magnitude of this ratio and its variation through time increased with depth. Growth conditions for heterotrophic bacteria in Chesapeake Bay during summer in surface waters and throughout the water column in fall may be relatively constant leading to balanced growth. In contrast, fluctuating growth conditions in subsurface waters during summer may lead to unbalanced growth

  5. Combined effect of zinc, chromium, and cadmium on bacterial biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Korsak, M N; Nakani, D V; Chol' naya, G G

    1976-01-01

    The present work was carried out at the Rybinskoye storage-lake in 1974. Some tolerance limits of zinc, chromium and cadmium were chosen for the investigation. The bacterial production was estimated by /sup 14/C heterotrophic assimilation. Natural water included in polyethylene reservoirs was used. The bacterial production was determined in one to three days after the beginning of the experiment. In most off the experiments the negative influence of zinc and chromium on the bacterial biomass production was registered only after 3 days of exposure. The effect of cadmium during the entire period of observations proved to be unreliable. The effect of chromium was fairly constant in different seasons. The interaction of toxicants was not revealed in any the of experiments. 8 references.

  6. Characterization and optimization of antibiotic resistant bacterial strains for polyhydroxyalkanoates (phas) production

    International Nuclear Information System (INIS)

    Rehman, S. U.; Jamil, N.; Hussain, S.

    2005-01-01

    In this investigation, sugarcane soil, sewage water and soil containing long chain hydrocarbons was screened to obtain bacterial strains that were able to synthesize poly-beta-hydroxyalkanoates (PHA). The potential to synthesize PHA was tested qualitatively by Sudan Black staining of colonies growing in glucose and sucrose. Sixteen bacterial strains were isolated, purified and characterized for Gram reaction, biochemical analysis and PHA production. Isolates showed a wide range of tolerance to different commonly used antibiotics. PHA extraction was done by solvent extraction and hypochlorite digestion method. PHA production was optimized for different nitrogen concentrations. (author)

  7. Aplikasi Wax Sebagai Salah Satu Material Di Bidang Kedokteran Gigi

    OpenAIRE

    Rika Jamilah Israwati Lubis

    2008-01-01

    Wax merupakan salah satu bahan termoplastik yang terdiri dari berbagai bahan organis dan bahan alami sehingga membuatnya sebagai bahan dengan sifat-sifat yang sangat berguna. Unsur-unsur pokok dental wax terdiri dari 3 suraber utama, yaitu : mineral, serangga (hewani), dan sayur-sayuran (tumbuh-tumbuhan). Wax yang berasal dari bahan mineral diantaranya adalah paraffin wax dan microcrystallin wax yang diperoleh dari hasil residu petroleum melalui proses destilasi. Wax yang berasal dari serangg...

  8. Amylase production under solid state fermentation by a bacterial ...

    African Journals Online (AJOL)

    This study was concerned with the screening of a suitable isolate and optimization of cultural conditions for the biosynthesis of thermostable amylase under solid state fermentation (SSF). Twenty seven isolates were screened for amylase production out of which one isolate designated as W74 showed maximal amylase ...

  9. PRODUCTIVITY OF GROWING PONDS WHEN APPLYING THE BACTERIAL FERTILIZER «PHOSPHOBAKTERIN»

    Directory of Open Access Journals (Sweden)

    Т. Hryhorenko

    2017-09-01

    Full Text Available Purpose. To investigate the effect of the bacterial fertilizer "Phosphobacterin" on the formation of the hydrochemical regime, development of the natural food supply and fish productivity in the growing ponds. Methodology. The work was conducted according to generally accepted hydrochemical,, microbiological, hydrobiological and fish farming methods. Findings The article presents the results of a study of the productivity of growing ponds with different methods of the application of the bacterial fertilizer "Phosphobacterin". It was found that the hydrochemical regime of the experimental ponds was formed under the effect of the source of water supply and measures aimed at intensifying the development of the natural food supply and was favorable for the development of feed organisms and the cultivation of fish seeds. Application of the bacterial fertilizer at the beginning of the growing season along the water pond surface proved to be little effective for increasing the productivity of the pond ecosystem as a whole. A more effective method of increasing biological productivity, including fish productivity of growing ponds, was the application of "Phosphobacterin" during the growing season both on the bed and on the water surface in combination with the organic fertilizer - cattle humus. In the experimental pond under complex fertilization, the average phytoplankton biomass during the growing season was 1.5 times, bacterioplankton 1.1 times, zoobenthos 2.6 times higher, and the obtained total fish productivity was 1.2 times higher than in the control pond (when applying only cattle humus. Originality. The peculiarities of formation of hydrochemical and hydrobiological (phyto-, bacterio-, zooplankton, zoobenthos regimes of growing ponds and the fishery indices are studied, both for bacterial fertilizer "Phosphobacterin" independently and together with the traditional organic fertilizer - cattle humus. Practical value. Based on the obtained results

  10. Wax inhibitor based on ethylene vinyl acetate with methyl methacrylate and diethanolamine for crude oil pipeline

    Science.gov (United States)

    Anisuzzaman, S. M.; Abang, S.; Bono, A.; Krishnaiah, D.; Karali, R.; Safuan, M. K.

    2017-06-01

    Wax precipitation and deposition is one of the most significant flow assurance challenges in the production system of the crude oil. Wax inhibitors are developed as a preventive strategy to avoid an absolute wax deposition. Wax inhibitors are polymers which can be known as pour point depressants as they impede the wax crystals formation, growth, and deposition. In this study three formulations of wax inhibitors were prepared, ethylene vinyl acetate, ethylene vinyl acetate co-methyl methacrylate (EVA co-MMA) and ethylene vinyl acetate co-diethanolamine (EVA co-DEA) and the comparison of their efficiencies in terms of cloud point¸ pour point, performance inhibition efficiency (%PIE) and viscosity were evaluated. The cloud point and pour point for both EVA and EVA co-MMA were similar, 15°C and 10-5°C, respectively. Whereas, the cloud point and pour point for EVA co-DEA were better, 10°C and 10-5°C respectively. In conclusion, EVA co-DEA had shown the best % PIE (28.42%) which indicates highest percentage reduction of wax deposit as compared to the other two inhibitors.

  11. Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications

    OpenAIRE

    Roca, Christophe; Alves, Vitor D.; Freitas, Filomena; Reis, Maria A. M.

    2015-01-01

    The authors acknowledge Fundacao para a Ciencia e Tecnologia (FC&T), Portugal, through projects PEst-C/EQB/LA0006/2013 and PTDC/AGR-ALI/114706/2009 - "New edible bioactive coatings for the improvement of food products quality." FF acknowledges FCT&T for Post-Doctoral fellowship SFRH/BPD/72280/2010. Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and com...

  12. Bacterial abundance and production in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Raghukumar, S.; Gauns, M.

    bacterial densities of about 1 x 10 sup(9) cells L sup(-1) were observed during the intermonsoon periods of September and April/May compared to the southwest monsoon period of July/August and the winter period of February/March. Although primary production...

  13. BacHBerry:: BACterial Hosts for production of Bioactive phenolics from bERRY fruits

    DEFF Research Database (Denmark)

    Dudnik, Alexey; Almeida, A. Filipa; Andrade, Ricardo

    2017-01-01

    BACterial Hosts for production of Bioactive phenolics from bERRY fruits (BacHBerry) was a 3-year project funded by the Seventh Framework Programme (FP7) of the European Union that ran between November 2013 and October 2016. The overall aim of the project was to establish a sustainable and economi...

  14. Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma : A nested case-control study

    NARCIS (Netherlands)

    Fedirko, Veronika; Tran, Hao Quang; Gewirtz, Andrew T.; Stepien, Magdalena; Trichopoulou, Antonia; Aleksandrova, Krasimira; Olsen, Anja; Tjønneland, Anne; Overvad, Kim; Carbonnel, Franck; Boutron-Ruault, Marie Christine; Severi, Gianluca; Kühn, Tilman; Kaaks, Rudolf; Boeing, Heiner; Bamia, Christina; Lagiou, Pagona; Grioni, Sara; Panico, Salvatore; Palli, Domenico; Tumino, Rosario; Naccarati, Alessio; Peeters, Petra H.; Bueno-de-Mesquita, H. B.; Weiderpass, Elisabete; Castaño, José María Huerta; Barricarte, Aurelio; Sánchez, María José; Dorronsoro, Miren; Quirós, J. Ramón; Agudo, Antonio; Sjöberg, Klas; Ohlsson, Bodil; Hemmingsson, Oskar; Werner, Mårten; Bradbury, Kathryn E.; Khaw, Kay Tee; Wareham, Nick; Tsilidis, Konstantinos K.; Aune, Dagfinn; Scalbert, Augustin; Romieu, Isabelle; Riboli, Elio; Jenab, Mazda

    2017-01-01

    Background: Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking. Methods: We used a case-control study design nested within a large

  15. Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications.

    Science.gov (United States)

    Roca, Christophe; Alves, Vitor D; Freitas, Filomena; Reis, Maria A M

    2015-01-01

    Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed.

  16. Polysaccharides enriched in rare sugars: bacterial sources, production and applications

    Directory of Open Access Journals (Sweden)

    Christophe eRoca

    2015-04-01

    Full Text Available Microbial extracellular polysaccharides (EPS, produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers.This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals and biomedical applications, are discussed.

  17. Use of the [14C]Leucine Incorporation Technique To Measure Bacterial Production in River Sediments and the Epiphyton

    OpenAIRE

    Fischer, Helmut; Pusch, Martin

    1999-01-01

    Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [14C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sedi...

  18. Production of Metabolites as Bacterial Responses to the Marine Environment

    Directory of Open Access Journals (Sweden)

    Pedro Fernandes

    2010-03-01

    Full Text Available Bacteria in marine environments are often under extreme conditions of e.g., pressure, temperature, salinity, and depletion of micronutrients, with survival and proliferation often depending on the ability to produce biologically active compounds. Some marine bacteria produce biosurfactants, which help to transport hydrophobic low water soluble substrates by increasing their bioavailability. However, other functions related to heavy metal binding, quorum sensing and biofilm formation have been described. In the case of metal ions, bacteria developed a strategy involving the release of binding agents to increase their bioavailability. In the particular case of the Fe3+ ion, which is almost insoluble in water, bacteria secrete siderophores that form soluble complexes with the ion, allowing the cells to uptake the iron required for cell functioning. Adaptive changes in the lipid composition of marine bacteria have been observed in response to environmental variations in pressure, temperature and salinity. Some fatty acids, including docosahexaenoic and eicosapentaenoic acids, have only been reported in prokaryotes in deep-sea bacteria. Cell membrane permeability can also be adapted to extreme environmental conditions by the production of hopanoids, which are pentacyclic triterpenoids that have a function similar to cholesterol in eukaryotes. Bacteria can also produce molecules that prevent the attachment, growth and/or survival of challenging organisms in competitive environments. The production of these compounds is particularly important in surface attached strains and in those in biofilms. The wide array of compounds produced by marine bacteria as an adaptive response to demanding conditions makes them suitable candidates for screening of compounds with commercially interesting biological functions. Biosurfactants produced by marine bacteria may be helpful to increase mass transfer in different industrial processes and in the bioremediation of

  19. Analysis of the constituents in jojoba wax used as a food additive by LC/MS/MS.

    Science.gov (United States)

    Tada, Atsuko; Jin, Zhe-Long; Sugimoto, Naoki; Sato, Kyoko; Yamazaki, Takeshi; Tanamoto, Kenichi

    2005-10-01

    Jojoba wax is a natural gum base used as a food additive in Japan, and is obtained from jojoba oil with a characteristically high melting point. Although the constituents of jojoba oil have been reported, the quality of jojoba wax used as a food additive has not yet been clarified. In order to evaluate its quality as a food additive and to obtain basic information useful for setting official standards, we investigated the constituents and their concentrations in jojoba wax. LC/MS analysis of the jojoba wax showed six peaks with [M+H]+ ions in the range from m/z 533.6 to 673.7 at intervals of m/z 28. After isolation of the components of the four main peaks by preparative LC/MS, the fatty acid and long chain alcohol moieties of the wax esters were analyzed by methanolysis and hydrolysis, followed by GC/MS. The results indicated that the main constituents in jojoba wax were various kinds of wax esters, namely eicosenyl octadecenoate (C20:1-C18:1) (1), eicosenyl eicosenoate (C20:1-C20:1) (II), docosenyl eicosenoate (C22:1-C20:1) (III), eicosenyl docosenoate (C20:1-C22:1) (IV) and tetracosenyl eiosenoate (C24:1-C20:1) (V). To confirm and quantify the wax esters in jojoba wax directly, LC/MS/MS analysis was performed. The product ions corresponding to the fatty acid moieties of the wax esters were observed, and by using the product ions derived from the protonated molecular ions of wax esters the fatty acid moieties were identified by MRM analysis. The concentrations of the wax esters I, II and III, in jojoba wax were 5.5, 21.4 and 37.8%, respectively. In summary, we clarified the main constituents of jojoba wax and quantified the molecular species of the wax esters without hydrolysis by monitoring their product ions, using a LC/MS/MS system.

  20. Ecosystem productivity is associated with bacterial phylogenetic distance in surface marine waters.

    Science.gov (United States)

    Galand, Pierre E; Salter, Ian; Kalenitchenko, Dimitri

    2015-12-01

    Understanding the link between community diversity and ecosystem function is a fundamental aspect of ecology. Systematic losses in biodiversity are widely acknowledged but the impact this may exert on ecosystem functioning remains ambiguous. There is growing evidence of a positive relationship between species richness and ecosystem productivity for terrestrial macro-organisms, but similar links for marine micro-organisms, which help drive global climate, are unclear. Community manipulation experiments show both positive and negative relationships for microbes. These previous studies rely, however, on artificial communities and any links between the full diversity of active bacterial communities in the environment, their phylogenetic relatedness and ecosystem function remain hitherto unexplored. Here, we test the hypothesis that productivity is associated with diversity in the metabolically active fraction of microbial communities. We show in natural assemblages of active bacteria that communities containing more distantly related members were associated with higher bacterial production. The positive phylogenetic diversity-productivity relationship was independent of community diversity calculated as the Shannon index. From our long-term (7-year) survey of surface marine bacterial communities, we also found that similarly, productive communities had greater phylogenetic similarity to each other, further suggesting that the traits of active bacteria are an important predictor of ecosystem productivity. Our findings demonstrate that the evolutionary history of the active fraction of a microbial community is critical for understanding their role in ecosystem functioning. © 2015 John Wiley & Sons Ltd.

  1. Enhanced biogas production from penicillin bacterial residue by thermal-alkaline pretreatment

    International Nuclear Information System (INIS)

    Zhong, Weizhang; Li, Guixia; Gao, Yan; Li, Zaixing; Geng, Xiaoling; Li, Yubing; Yang, Jingliang; Zhou, Chonghui

    2015-01-01

    In this study, the orthogonal experimental design was used to determine the optimum conditions for the effect of thermal alkaline; pretreatment on the anaerobic digestion of penicillin bacterial residue. The biodegradability of the penicillin; bacterial residue was evaluated by biochemical methane potential tests in laboratory. The optimum values of temperature,; alkali concentration, pretreatment time and moisture content for the thermal-alkaline pretreatment were determined as; 70 °C, 6% (w/v), 30 min, and 85%, respectively. Thermal-alkaline pretreatment could significantly enhance the soluble; chemical oxygen demand solubilization, the suspended solid solubilization and the biodegradability. Biogas production; was enhanced by the thermal-alkaline pretreatment, probably as a result of the breakdown of cell walls and membranes of; micro-organisms, which may facilitate the contact between organic molecules and anaerobic microorganisms.; Keywords: penicillin bacterial residue; anaerobic digestion; biochemical methane potential tests; pretreatment

  2. Factors affecting the bacterial community composition and heterotrophic production of Columbia River estuarine turbidity maxima.

    Science.gov (United States)

    Herfort, Lydie; Crump, Byron C; Fortunato, Caroline S; McCue, Lee Ann; Campbell, Victoria; Simon, Holly M; Baptista, António M; Zuber, Peter

    2017-12-01

    Estuarine turbidity maxima (ETM) function as hotspots of microbial activity and diversity in estuaries, yet, little is known about the temporal and spatial variability in ETM bacterial community composition. To determine which environmental factors affect ETM bacterial populations in the Columbia River estuary, we analyzed ETM bacterial community composition (Sanger sequencing and amplicon pyrosequencing of 16S rRNA gene) and bulk heterotrophic production ( 3 H-leucine incorporation rates). We collected water 20 times to cover five ETM events and obtained 42 samples characterized by different salinities, turbidities, seasons, coastal regimes (upwelling vs. downwelling), locations, and particle size. Spring and summer populations were distinct. All May samples had similar bacterial community composition despite having different salinities (1-24 PSU), but summer non-ETM bacteria separated into marine, freshwater, and brackish assemblages. Summer ETM bacterial communities varied depending on coastal upwelling or downwelling conditions and on the sampling site location with respect to tidal intrusion during the previous neap tide. In contrast to ETM, whole (>0.2 μm) and free-living (0.2-3 μm) assemblages of non-ETM waters were similar to each other, indicating that particle-attached (>3 μm) non-ETM bacteria do not develop a distinct community. Brackish water type (ETM or non-ETM) is thus a major factor affecting particle-attached bacterial communities. Heterotrophic production was higher in particle-attached than free-living fractions in all brackish waters collected throughout the water column during the rise to decline of turbidity through an ETM event (i.e., ETM-impacted waters). However, free-living communities showed higher productivity prior to or after an ETM event (i.e., non-ETM-impacted waters). This study has thus found that Columbia River ETM bacterial communities vary based on seasons, salinity, sampling location, and particle size, with the

  3. 21 CFR 872.6890 - Intraoral dental wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraoral dental wax. 872.6890 Section 872.6890...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6890 Intraoral dental wax. (a) Identification. Intraoral dental wax is a device made of wax intended to construct patterns from which custom made metal...

  4. 21 CFR 172.888 - Synthetic petroleum wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic petroleum wax. 172.888 Section 172.888... CONSUMPTION Multipurpose Additives § 172.888 Synthetic petroleum wax. Synthetic petroleum wax may be safely used in or on foods in accordance with the following conditions: (a) Synthetic petroleum wax is a...

  5. Extracting paraffin and mineral waxes

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, I C

    1930-01-17

    In a process for freezing liquids, particularly for precipitating wax from oils such as petroleum or shale oils, the liquid to be treated is cooled first in vessels 10, 11, and 12 by chilled liquid from the final separating tanks 22, then in vessels 13, 14 and 15 by brine cooled by an evaporator 38 and finally in vessels 16,17, 18 directly by the evaporator of a refrigerating plant. The cooling in vessels 10, 11, 12 is regulated by recirculating some of the chilled liquid through the valved pipe 30 while that in tanks 13, 14, 15 is regulated by short-circuiting the brine circulation through a tank 35. Refrigerant vapour from the evaporators in vessels 16, 17, 18 may return through pipe 61 to the compressor or absorber of the plant 45 or it may be withdrawn by pump 58. By the operation of valves A, B, 47, and a valve in pipe 61, the pressures in the evaporators may be varied individually to regulate the cooling in each vessel. Mechanical stirrers are provided in tanks 16, 17, 18.

  6. Refining of wax-containing oil by distillation

    Energy Technology Data Exchange (ETDEWEB)

    1930-04-28

    A continuous method is disclosed for producing low cold test oil from wax-containing mineral oil, which comprises continuously heating the oil in a tubular heater with avoidance of cracking, and fractionating the resulting liquid and vapor in a fractionating tower with reflux to produce a wax-containing fraction having therein substantially all of the amorphous wax and being sufficiently free of crystalline wax so as to be waxable by a method suitable for the removal of amorphous wax.

  7. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing; Yi, Xin; Xiao, Kang; Li, Shunbo; Kodzius, Rimantas; Qin, Jianhua; Wen, Weijia

    2013-01-01

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  8. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing

    2013-10-10

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  9. The effect of antibiotics on associated bacterial community of stored product mites.

    Directory of Open Access Journals (Sweden)

    Jan Kopecky

    Full Text Available Bacteria are associated with the gut, fat bodies and reproductive organs of stored product mites (Acari: Astigmata. The mites are pests due to the production of allergens. Addition of antibiotics to diets can help to characterize the association between mites and bacteria.Ampicillin, neomycin and streptomycin were added to the diets of mites and the effects on mite population growth (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae and associated bacterial community structure were assessed. Mites were treated by antibiotic supplementation (1 mg g(-1 of diet for 21 days and numbers of mites and bacterial communities were analyzed and compared to the untreated control. Bacterial quantities, determined by real-time PCR, significantly decreased in antibiotic treated specimens from 5 to 30 times in A. siro and T. putrescentiae, while no decline was observed in L. destructor. Streptomycin treatment eliminated Bartonella-like bacteria in the both A. siro and T. putrescentiae and Cardinium in T. putrescentiae. Solitalea-like bacteria proportion increased in the communities of neomycin and streptomycin treated A. siro specimens. Kocuria proportion increased in the bacterial communities of ampicillin and streptomycin treated A. siro and neomycin and streptomycin treated L. destructor.The work demonstrated the changes of mite associated bacterial community under antibiotic pressure in pests of medical importance. Pre-treatment of mites by 1 mg g(-1 antibiotic diets improved mite fitness as indicated accelerated population growth of A. siro pretreated streptomycin and neomycin and L. destructor pretreated by neomycin. All tested antibiotics supplemented to diets caused the decrease of mite growth rate in comparison to the control diet.

  10. Thin stillage supplementation greatly enhances bacterial cellulose production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Wu, Jyh-Ming; Liu, Ren-Han

    2012-09-01

    Thin stillage (TS), a wastewater from rice wine distillery can well sustain the growth of Gluconacetobacter xylinus for production of bacterial cellulose (BC). When used as a supplement to the traditional BC production medium (Hestrin and Schramm medium), the enhancement of BC production increased with the amount of TS supplemented in a static culture of G. xylinus. When TS was employed to replace distilled water for preparing HS medium (100%TS-HS medium), the BC production in this 100%TS-HS medium was enhanced 2.5-fold to a concentration of 10.38 g/l with sugar to BC conversion yield of 57% after 7 days cultivation. The cost-free TS as a supplement in BC production medium not only can greatly enhance the BC production, but also can effectively dispose the nuisance wastewater of rice wine distillery. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Dark fermentative biohydrogen production by mesophilic bacterial consortia isolated from riverbed sediments

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sneha; Sudhakaran, Anu K.; Sarma, Priyangshu Manab; Subudhi, Sanjukta; Mandal, Ajoy Kumar; Lal, Banwari [Environmental and Industrial Biotechnology Division, The Energy and Resources Institute (TERI), Habitat Place, Darbari Seth Block, Lodhi Road, New Delhi 110003 (India); Gandham, Ganesh [Hindustan Petroleum Corporation Limited, Mumbai Refinery, B. D. Patil Marg, Mahul, Mumbai 400074 (India)

    2010-10-15

    Dark fermentative bacterial strains were isolated from riverbed sediments and investigated for hydrogen production. A series of batch experiments were conducted to study the effect of pH, substrate concentration and temperature on hydrogen production from a selected bacterial consortium, TERI BH05. Batch experiments for fermentative conversion of sucrose, starch, glucose, fructose, and xylose indicated that TERI BH05 effectively utilized all the five sugars to produce fermentative hydrogen. Glucose was the most preferred carbon source indicating highest hydrogen yields of 22.3 mmol/L. Acetic and butyric acid were the major soluble metabolites detected. Investigation on optimization of pH, temperature, and substrate concentration revealed that TERI BH05 produced maximum hydrogen at 37 C, pH 6 with 8 g/L of glucose supplementation and maximum yield of hydrogen production observed was 2.0-2.3 mol H{sub 2}/mol glucose. Characterization of TERI BH05 revealed the presence of two different bacterial strains showing maximum homology to Clostridium butyricum and Clostridium bifermentans. (author)

  12. Screening of Acetic Acid Bacteria from Pineapple Waste for Bacterial Cellulose Production using Sago Liquid Waste

    Directory of Open Access Journals (Sweden)

    Nur Arfa Yanti

    2017-12-01

    Full Text Available Bacterial cellulose is a biopolymer produced by fermentation process with the help of bacteria. It has numerous applications in industrial sector with its characteristic as a biodegradable and nontoxic compound in nature. The potential application of BC is limited by its production costs, because BC is produced from expensive culture media. The use of cheap carbon and nutrient sources such as sago liquid waste is an interesting strategy to overcome this limitation. The objective of this study was to obtain the AAB strain that capable to produce bacterial cellulose from sago liquid waste. Isolation of AAB strains was conducted using CARR media and the screening of BC production was performed on Hestrin-Schramm (HS media with glucose as a carbon source. The strains of AAB then were evaluated for their cellulose-producing capability using sago liquid waste as a substrate. Thirteen strains of AAB producing BC were isolated from pineapple waste (pineapple core and peel and seven of them were capable to produce BC using sago liquid waste substrate. One of the AAB strains produced a relatively high BC, i.e. isolate LKN6. The result of morphological and biochemical test was proven that the bacteria was Acetobacter xylinum. The result of this study showed that A. xylinum LKN6 can produce a high yield of BC, therefore this strain is potentially useful for its utilization as a starter in bacterial cellulose production

  13. Performance of improved bacterial cellulose application in the production of functional paper.

    Science.gov (United States)

    Basta, A H; El-Saied, H

    2009-12-01

    The purpose of this work was to study the feasibility of producing economic flame retardant bacterial cellulose (BC) and evaluating its behaviour in paper production. This type of BC was prepared by Gluconacetobacter subsp. xylinus and substituting the glucose in the cultivation medium by glucose phosphate as a carbon source; as well as using corn steep liquor as a nitrogen source. The investigated processing technique did not dispose any toxic chemicals that pollute the surroundings or cause unacceptable effluents, making the process environmentally safe. The fire retardant behaviour of the investigated BC has been studied by non-isothermal thermogravimetric analysis (TGA & DTGA). The activation energy of each degradation stage and the order of degradation were estimated using the Coats-Redfern equation and the least square method. Strength, optical properties, and thermogravimetric analysis of BC-phosphate added paper sheets were also tested. The study confirmed that the use of glucose phosphate along with glucose was significant in the high yield production of phosphate containing bacterial cellulose (PCBC1); more so than the use of glucose phosphate alone (PCBC2). Incorporating 5% of the PCBC with wood pulp during paper sheet formation was found to significantly improve kaolin retention, strength, and fire resistance properties as compared to paper sheets produced from incorporating bacterial cellulose (BC). This modified BC is a valuable product for the preparation of specialized paper, in addition to its function as a fillers aid.

  14. Indigenous bacteria and bacterial metabolic products in the gastrointestinal tract of broiler chickens.

    Science.gov (United States)

    Rehman, Habib Ur; Vahjen, Wilfried; Awad, Wageha A; Zentek, Jürgen

    2007-10-01

    The gastrointestinal tract is a dynamic ecosystem containing a complex microbial community. In this paper, the indigenous intestinal bacteria and the microbial fermentation profile particularly short chain fatty acids (SCFA), lactate, and ammonia concentrations are reviewed. The intestinal bacterial composition changes with age. The bacterial density of the small intestine increases with age and comprises of lactobacilli, streptococci, enterobacteria, fusobacteria and eubacteria. Strict anaerobes (anaerobic gram-positive cocci, Eubacterium spp., Clostridium spp., Lactobacillus spp., Fusobacterium spp. and Bacteroides) are predominating caecal bacteria in young broilers. Data from culture-based studies showed that bifidobacteria could not be isolated from young birds, but were recovered from four-week-old broilers. Caecal lactobacilli accounted for 1.5-24% of the caecal bacteria. Gene sequencing of caecal DNA extracts showed that the majority of bacteria belonged to Clostridiaceae. Intestinal bacterial community is influenced by the dietary ingredients, nutrient levels and physical structure of feed. SCFA and other metabolic products are affected by diet formulation and age. Additional studies are required to know the bacterial metabolic activities together with the community analysis of the intestinal bacteria. Feed composition and processing have great potential to influence the activities of intestinal bacteria towards a desired direction in order to support animal health, well-being and microbial safety of broiler meat.

  15. Recombinant Plants Provide a New Approach to the Production of Bacterial Polysaccharide for Vaccines

    Science.gov (United States)

    Smith, Claire M.; Fry, Stephen C.; Gough, Kevin C.; Patel, Alexandra J. F.; Glenn, Sarah; Goldrick, Marie; Roberts, Ian S.; Andrew, Peter W.

    2014-01-01

    Bacterial polysaccharides have numerous clinical or industrial uses. Recombinant plants could offer the possibility of producing bacterial polysaccharides on a large scale and free of contaminating bacterial toxins and antigens. We investigated the feasibility of this proposal by cloning and expressing the gene for the type 3 synthase (cps3S) of Streptococcus pneumoniae in Nicotinia tabacum, using the pCambia2301 vector and Agrobacterium tumefaciens-mediated gene transfer. In planta the recombinant synthase polymerised plant-derived UDP-glucose and UDP-glucuronic acid to form type 3 polysaccharide. Expression of the cps3S gene was detected by RT-PCR and production of the pneumococcal polysaccharide was detected in tobacco leaf extracts by double immunodiffusion, Western blotting and high-voltage paper electrophoresis. Because it is used a component of anti-pneumococcal vaccines, the immunogenicity of the plant-derived type 3 polysaccharide was tested. Mice immunised with extracts from recombinant plants were protected from challenge with a lethal dose of pneumococci in a model of pneumonia and the immunised mice had significantly elevated levels of serum anti-pneumococcal polysaccharide antibodies. This study provides the proof of the principle that bacterial polysaccharide can be successfully synthesised in plants and that these recombinant polysaccharides could be used as vaccines to protect against life-threatening infections. PMID:24498433

  16. Heterotrophic bacterial production and metabolic balance during the VAHINE mesocosm experiment in the New Caledonia lagoon

    Science.gov (United States)

    Van Wambeke, France; Pfreundt, Ulrike; Barani, Aude; Berthelot, Hugo; Moutin, Thierry; Rodier, Martine; Hess, Wolfgang R.; Bonnet, Sophie

    2016-06-01

    Studies investigating the fate of diazotrophs through the microbial food web are lacking, although N2 fixation can fuel up to 50 % of new production in some oligotrophic oceans. In particular, the role played by heterotrophic prokaryotes in this transfer is largely unknown. In the frame of the VAHINE (VAriability of vertical and tropHIc transfer of diazotroph derived N in the south wEst Pacific) experiment, three replicate large-volume (˜ 50 m3) mesocosms were deployed for 23 days in the new Caledonia lagoon and were intentionally fertilized on day 4 with dissolved inorganic phosphorus (DIP) to stimulate N2 fixation. We specifically examined relationships between heterotrophic bacterial production (BP) and N2 fixation or primary production, determined bacterial growth efficiency and established carbon budgets. BP was statistically higher during the second phase of the experiment (P2: days 15-23), when chlorophyll biomass started to increase compared to the first phase (P1: days 5-14). Phosphatase alkaline activity increased drastically during the second phase of the experiment, showing adaptations of microbial populations after utilization of the added DIP. Notably, among autotrophs, Synechococcus abundances increased during P2, possibly related to its capacity to assimilate leucine and to produce alkaline phosphatase. Bacterial growth efficiency based on the carbon budget (27-43 %), was notably higher than generally cited for oligotrophic environments and discussed in links with the presence of abundant species of bacteria expressing proteorhodopsin. The main fates of gross primary production (particulate + dissolved) were respiration (67 %) and export through sedimentation (17 %). BP was highly correlated with particulate primary production and chlorophyll biomass during both phases of the experiment but was slightly correlated, and only during P2 phase, with N2 fixation rates. Heterotrophic bacterial production was strongly stimulated after mineral N enrichment

  17. Policosanol fabrication from insect wax and optimization by response surface methodology.

    Science.gov (United States)

    Ma, Jinju; Ma, Liyi; Zhang, Hong; Zhang, Zhongquan; Wang, Youqiong; Li, Kai; Chen, Xiaoming

    2018-01-01

    Insect wax is a famous biological resource for the role in economic production in China. Insect wax is a good source of policosanol, which may is a candidate supplement in foodstuff and pharmaceuticals that has important physiological activities. Therefore, this work aims to investigate a high-yield and rapid method for policosanol fabrication from insect wax. The conditions for policosanol fabrication were optimized as follows: an oil bath temperature of 112.7°C and reductant dosage of 0.97 g (used for the reduction of 10.00 g of insect wax). The yield of policosanol reached 83.20%, which was 4 times greater than that of existing methods, such as saponification. The total content of policosanol obtained under the optimal conditions reached 87%. In other words, a high yield of policosanol was obtained from insect wax (723.84 mg/g), that was 55 times higher than that generated from beeswax-brown via saponification. The concentrations of metal residues in policosanol were within the limits of the European Union regulations and EFSA stipulation. The LD50 values for oral doses of insect wax and policosanol were both > 5 g/kg. Policosanol was fabricated via solvent-free reduction from insect wax using LiAlH4 at a high yield. The fabrication conditions were optimized. Policosanol and insect wax showed high security, which made them potential candidates as supplements in foods, pharmaceuticals and cosmetics. The rapid and high-yield method has great potential for commercial manufacturing of policosanol.

  18. Methane production and small intestinal bacterial overgrowth in children living in a slum.

    Science.gov (United States)

    Mello, Carolina Santos; Tahan, Soraia; Melli, Lígia Cristina F L; Rodrigues, Mirian Silva do Carmo; de Mello, Ricardo Martin Pereira; Scaletsky, Isabel Cristina Affonso; de Morais, Mauro Batista

    2012-11-07

    To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests. This transversal study included 85 children residing in a slum and 43 children from a private school, all aged between 6 and 10 years, in Osasco, Brazil. For characterization of the groups, data regarding the socioeconomic status and basic housing sanitary conditions were collected. Anthropometric data was obtained in children from both groups. All children completed the hydrogen (H(2)) and methane (CH(4)) breath test in order to assess small intestinal bacterial overgrowth (SIBO). SIBO was diagnosed when there was an increase in H(2) ≥ 20 ppm or CH(4) ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion. Children from the slum group had worse living conditions and lower nutritional indices than children from the private school. SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P = 0.0007). Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P = 0.007). A higher concentration of hydrogen in the small intestine (P slum group with SIBO when compared to children from the slum group without SIBO. Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P slum. Colonic production of hydrogen was lower in methane-producing children (P = 0.017). Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production. Hydrogen is a substrate for methane production in the colon.

  19. Effects of carbon dioxide on metabolite production and bacterial communities during kimchi fermentation.

    Science.gov (United States)

    Park, Doo Hyun

    2018-04-24

    Bacterial communities and metabolites in kimchi fermented under conventional conditions (CC) compared to CO 2 -rich environments (CO 2 ) were analyzed. After a 20-day fermentation, lactic and acetic acid productions were 54 and 69 mM under CC, and 19 and 12 mM under CO 2 , respectively. The final pH of kimchi fermented under CC (CC-fermenting) and CO 2 (CO 2 -fermenting) were 4.1 and 4.7, respectively. For bacterial communities, OTU and Chao1 indices were both 35 in fresh kimchi, 10 and 15 in CC-fermenting kimchi, and 8 and 24 in CO 2 -fermenting kimchi, respectively. Shannon and Simpson indices were 3.47 and 0.93 in fresh kimchi, 1.87-0.06 and 0.46-0.01 in CC-fermenting kimchi, and 1.65-0.44 and 0.63-0.12 in CO 2 -fermenting kimchi, respectively. Non-lactic acid bacteria were eliminated in fermenting kimchi after 12 days under CC and 6 days under CO 2 . I conclude that carbon dioxide can alter bacterial communities, reduce metabolite production, and improve fermented kimchi quality.

  20. Improvement production of bacterial cellulose by semi-continuous process in molasses medium.

    Science.gov (United States)

    Cakar, Fatih; Ozer, Işılay; Aytekin, A Özhan; Sahin, Fikrettin

    2014-06-15

    Bacterial cellulose (BC) has unique properties such as structural, functional, physical and chemical. The mass production of BC for industrial application has recently become attractive to produce more economical and high productive cellulose. In this study, to improve the productivity of bacterial cellulose (BC), BC production by Gluconacetobacter xylinus FC01 was investigated in molasses medium with static semi-continuous operation mode. Cell dry weight, polysaccharide, sugar and cellulose concentrations were monitored and cellulose was characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The highest cellulose yield (1.637 g/L) was obtained in SCP50-7d, which molasses of 1/2 ratio for 7 days by static semi-continuous operation mode. The results show that BC can be highly produced by G. xylinus in molasses with static semi-continuous process than batch process. We claimed that low-cost medium with semi-continuous operation mode in static culture is a good candidate for industrial scale BC productions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Modeling the hydration process of bean grains coated with carnauba wax

    Directory of Open Access Journals (Sweden)

    Aline Almeida da Paixão

    2017-08-01

    Full Text Available Edible waxes are widely used to maintain foodstuff until they are consumed. However, some products may be subjected to industrial procedures, such as hydration, prior to their consumption. Hydration of a material is a complex process, which aims to reconstitute the original characteristics of a product when in contact with a liquid phase. An important agricultural product that requires this procedure is beans. Thus, the purpose of this work is to study the hydration process of beans (cultivar BRSMG Majestoso in different temperatures and concentrations of carnauba wax, which is applied on the product surface. Beans with initial moisture content of 0.2015, 0.1972 and 0.1745 (d.b. corresponding to treatments 0 (witness, 1 (wax diluted in water in the ratio 1:1, and 2 (carnauba wax, without dilution were used. Later, these samples were imbibed in distilled water at temperatures of 20, 30 and 40 ºC, for 15 h. The temperature and the carnauba wax influenced the water absorption rate. The Peleg model described satisfactory experimental data and the Mitscherlich model presented biased residual distribution. The constants C1 and C2 of the Peleg model exhibited opposite behaviors with increasing temperatures in the hydration process.

  2. Characterization of the bacterial metagenome in an industrial algae bioenergy production system

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shi [Chinese Academy of Sciences; Fulbright, Scott P [Colorado State University; Zeng, Xiaowei [Chinese Academy of Sciences; Yates, Tracy [Solix Biofuels; Wardle, Greg [Solix Biofuels; Chisholm, Stephen T [Colorado State University; Xu, Jian [Chinese Academy of Sciences; Lammers, Peter [New Mexico State University

    2011-03-16

    Cultivation of oleaginous microalgae for fuel generally requires growth of the intended species to the maximum extent supported by available light. The presence of undesired competitors, pathogens and grazers in cultivation systems will create competition for nitrate, phosphate, sulfate, iron and other micronutrients in the growth medium and potentially decrease microalgal triglyceride production by limiting microalgal health or cell density. Pathogenic bacteria may also directly impact the metabolism or survival of individual microalgal cells. Conversely, symbiotic bacteria that enhance microalgal growth may also be present in the system. Finally, the use of agricultural and municipal wastes as nutrient inputs for microalgal production systems may lead to the introduction and proliferation of human pathogens or interfere with the growth of bacteria with beneficial effects on system performance. These considerations underscore the need to understand bacterial community dynamics in microalgal production systems in order to assess microbiome effects on microalgal productivity and pathogen risks. Here we focus on the bacterial component of microalgal production systems and describe a pipeline for metagenomic characterization of bacterial diversity in industrial cultures of an oleaginous alga, Nannochloropsis salina. Environmental DNA was isolated from 12 marine algal cultures grown at Solix Biofuels, a region of the 16S rRNA gene was amplified by PCR, and 16S amplicons were sequenced using a 454 automated pyrosequencer. The approximately 70,000 sequences that passed quality control clustered into 53,950 unique sequences. The majority of sequences belonged to thirteen phyla. At the genus level, sequences from all samples represented 169 different genera. About 52.94% of all sequences could not be identified at the genus level and were classified at the next highest possible resolution level. Of all sequences, 79.92% corresponded to 169 genera and 70 other taxa. We

  3. Bacterial Glycosyltransferases: Challenges and opportunities of a highly diverse enzyme class toward tailoring natural products

    Directory of Open Access Journals (Sweden)

    Jochen eSchmid

    2016-02-01

    Full Text Available The enzyme subclass of glycosyltransferases (EC 2.4 currently comprises 97 families as specified by CAZy classification. One of their important roles is in the biosynthesis of disaccharides, oligosaccharides and polysaccharides by catalyzing the transfer of sugar moieties from activated donor molecules to other sugar molecules. In addition glycosyltransferases also catalyze the transfer of sugar moieties onto aglycons, which is of great relevance for the synthesis of many high value natural products. Bacterial glycosyltransferases show a higher sequence similarity in comparison to mammalian ones. Even when most glycosyltransferases are poorly explored, state of the art technologies, such as protein engineering, domain swapping or computational analysis strongly enhance our understanding and utilization of these very promising classes of proteins. This perspective article will focus on bacterial glycosyltransferases, especially on classification, screening and engineering strategies to alter substrate specificity. The future development in these fields as well as obstacles and challenges will be highlighted and discussed.

  4. Auto-production of biosurfactants reverses the coffee ring effect in a bacterial system

    Science.gov (United States)

    Sempels, Wouter; de Dier, Raf; Mizuno, Hideaki; Hofkens, Johan; Vermant, Jan

    2013-04-01

    The deposition of material at the edge of evaporating droplets, known as the ‘coffee ring effect’, is caused by a radially outward capillary flow. This phenomenon is common to a wide array of systems including colloidal and bacterial systems. The role of surfactants in counteracting these coffee ring depositions is related to the occurrence of local vortices known as Marangoni eddies. Here we show that these swirling flows are universal, and not only lead to a uniform deposition of colloids but also occur in living bacterial systems. Experiments on Pseudomonas aeruginosa suggest that the auto-production of biosurfactants has an essential role in creating a homogeneous deposition of the bacteria upon drying. Moreover, at biologically relevant conditions, intricate time-dependent flows are observed in addition to the vortex regime, which are also effective in reversing the coffee ring effect at even lower surfactant concentrations.

  5. 2,4,6-Trinitrotoluene mineralization and bacterial production rates of natural microbial assemblages from coastal sediments

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, Michael T., E-mail: michael.montgomery@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Coffin, Richard B., E-mail: richard.coffin@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Boyd, Thomas J., E-mail: thomas.boyd@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Smith, Joseph P., E-mail: joseph.smith@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Walker, Shelby E., E-mail: Shelby.Walker@noaa.gov [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Osburn, Christopher L., E-mail: chris_osburn@ncsu.edu [Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695 (United States)

    2011-12-15

    The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO{sub 2}); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO{sub 2} was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 {mu}g C kg{sup -1} d{sup -1}). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO{sub 2} is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: > TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. > TNT mineralization rates comprised a significant proportion of total heterotrophic production. > These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO{sub 2} is a common feature of natural bacterial assemblages in coastal sediment.

  6. 2,4,6-Trinitrotoluene mineralization and bacterial production rates of natural microbial assemblages from coastal sediments

    International Nuclear Information System (INIS)

    Montgomery, Michael T.; Coffin, Richard B.; Boyd, Thomas J.; Smith, Joseph P.; Walker, Shelby E.; Osburn, Christopher L.

    2011-01-01

    The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO 2 ); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO 2 was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 μg C kg -1 d -1 ). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO 2 is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: → TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. → TNT mineralization rates comprised a significant proportion of total heterotrophic production. → These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO 2 is a common feature of natural bacterial assemblages in coastal sediment.

  7. Contrasting ability to take up leucine and thymidine among freshwater bacterial groups: implications for bacterial production measurements

    Science.gov (United States)

    Pérez, María Teresa; Hörtnagl, Paul; Sommaruga, Ruben

    2010-01-01

    We examined the ability of different freshwater bacterial groups to take up leucine and thymidine in two lakes. Utilization of both substrates by freshwater bacteria was examined at the community level by looking at bulk incorporation rates and at the single-cell level by combining fluorescent in situ hybridization and signal amplification by catalysed reporter deposition with microautoradiography. Our results showed that leucine was taken up by 70–80% of Bacteria-positive cells, whereas only 15–43% of Bacteria-positive cells were able to take up thymidine. When a saturating substrate concentration in combination with a short incubation was used, 80–90% of Betaproteobacteria and 67–79% of Actinobacteria were positive for leucine uptake, whereas thymidine was taken up by bacterial group. Bacterial abundance was a good predictor of the relative contribution of bacterial groups to leucine uptake, whereas when thymidine was used Actinobacteria represented the large majority (> 80%) of the cells taking up this substrate. Increasing the substrate concentration to 100 nM did not affect the percentage of R-BT cells taking up leucine (> 90% even at low concentrations), but moderately increased the fraction of thymidine-positive R-BT cells to a maximum of 35% of the hybridized cells. Our results show that even at very high concentrations, thymidine is not taken up by all, otherwise active, bacterial cells. PMID:19725866

  8. Understanding the distribution of natural wax in starch-wax films using synchrotron-based FTIR (S-FTIR).

    Science.gov (United States)

    Muscat, Delina; Tobin, Mark J; Guo, Qipeng; Adhikari, Benu

    2014-02-15

    High amylose starch-glycerol (HAG) films were produced incorporating beeswax, candelilla wax and carnauba wax in the presence and absence of Tween-80 in order to determine the distribution of wax in the films during the film formation process. The distribution of these waxes within the film was studied using Synchrotron based Fourier Transform Infrared Spectroscopy (S-FTIR) which provided 2D mapping along the thickness of the film. The incorporation of 5% and 10% wax in HAG films produced randomly distributed wax or wax-rich domains, respectively, within these films. Consequently, the addition of these waxes to HAG increased the surface roughness and hydrophobicity of these films. The addition of Tween-80 caused variations in wax-rich bands within the films. The HAG+carnauba wax+Tween-80 films exhibited domed wax-rich domains displayed with high integrated CH2 absorption value at the interior of the films, rougher surface and higher contact angle values than the other films. The S-FTIR 2D images indicated that the distribution of wax in starch-wax films correlated with the roughness and hydrophobicity of the starch-wax films. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Strategies for cost-effective and enhanced production of bacterial cellulose.

    Science.gov (United States)

    Islam, Mazhar Ul; Ullah, Muhammad Wajid; Khan, Shaukat; Shah, Nasrullah; Park, Joong Kon

    2017-09-01

    Bacterial cellulose (BC) has received substantial attention because of its high purity, mechanical strength, crystallinity, liquid-absorbing capabilities, biocompatibility, and biodegradability etc. These properties allow BC to be used in various fields, especially in industries producing medical, electronic, and food products etc. A major discrepancy associated with BC is its high production cost, usually much higher than the plant cellulose. To address this limitations, researchers have developed several strategies for enhanced production of BC including the designing of advanced reactors and utilization of various carbon sources. Another promising approach is the production of BC from waste materials such as food, industrial, agricultural, and brewery wastes etc. which not only reduces the overall BC production cost but is also environment-friendly. Besides, exploration of novel and efficient BC producing microbial strains provides impressive boost to the BC production processes. To this end, development of genetically engineered microbial strains has proven useful for enhanced BC production. In this review, we have summarized major efforts to enhance BC production in order to make it a cost-effective biopolymer. This review can be of interest to researchers investigating strategies for enhanced BC production, as well as companies exploring pilot projects to scale up BC production for industrial applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A Novel Platform for Evaluating the Environmental Impacts on Bacterial Cellulose Production.

    Science.gov (United States)

    Basu, Anindya; Vadanan, Sundaravadanam Vishnu; Lim, Sierin

    2018-04-10

    Bacterial cellulose (BC) is a biocompatible material with versatile applications. However, its large-scale production is challenged by the limited biological knowledge of the bacteria. The advent of synthetic biology has lead the way to the development of BC producing microbes as a novel chassis. Hence, investigation on optimal growth conditions for BC production and understanding of the fundamental biological processes are imperative. In this study, we report a novel analytical platform that can be used for studying the biology and optimizing growth conditions of cellulose producing bacteria. The platform is based on surface growth pattern of the organism and allows us to confirm that cellulose fibrils produced by the bacteria play a pivotal role towards their chemotaxis. The platform efficiently determines the impacts of different growth conditions on cellulose production and is translatable to static culture conditions. The analytical platform provides a means for fundamental biological studies of bacteria chemotaxis as well as systematic approach towards rational design and development of scalable bioprocessing strategies for industrial production of bacterial cellulose.

  11. Bacterial Standing Stock, Activity, and Carbon Production during Formation and Growth of Sea Ice in the Weddell Sea, Antarctica.

    Science.gov (United States)

    Grossmann, S; Dieckmann, G S

    1994-08-01

    Bacterial response to formation and growth of sea ice was investigated during autumn in the northeastern Weddell Sea. Changes in standing stock, activity, and carbon production of bacteria were determined in successive stages of ice development. During initial ice formation, concentrations of bacterial cells, in the order of 1 x 10 to 3 x 10 liter, were not enhanced within the ice matrix. This suggests that physical enrichment of bacteria by ice crystals is not effective. Due to low concentrations of phytoplankton in the water column during freezing, incorporation of bacteria into newly formed ice via attachment to algal cells or aggregates was not recorded in this study. As soon as the ice had formed, the general metabolic activity of bacterial populations was strongly suppressed. Furthermore, the ratio of [H]leucine incorporation into proteins to [H]thymidine incorporation into DNA changed during ice growth. In thick pack ice, bacterial activity recovered and growth rates up to 0.6 day indicated actively dividing populations. However, biomass-specific utilization of organic compounds remained lower than in open water. Bacterial concentrations of up to 2.8 x 10 cells liter along with considerably enlarged cell volumes accumulated within thick pack ice, suggesting reduced mortality rates of bacteria within the small brine pores. In the course of ice development, bacterial carbon production increased from about 0.01 to 0.4 mug of C liter h. In thick ice, bacterial secondary production exceeded primary production of microalgae.

  12. Thermal Cracking to Improve the Qualification of the Waxes

    Science.gov (United States)

    He, B.; Agblevor, F. A.; Chen, C. G.; Feng, J.

    2018-05-01

    Thermal cracking of waxes at mild conditions (430-500°C) has been reconsidered as a possible refining technology for the production of fuels and chemicals. In this study, the more moderate thermal cracking was investigated to process Uinta Basin soft waxes to achieve the required pour point so that they can be pumped to the refineries. The best thermal cracking conditions were set 420°C and 20 minutes. The viscosity and density of the final liquid product were respectively achieved as 2.63 mP•s and 0.784 g/cm3 at 40°C. The result of FT-IR analysis of the liquid product indicated that the unsaturated hydrocarbons were produced after thermal cracking, which was corroborated by the 13C NMR spectrum. The GC analysis of the final gas product indicated that the hydrogen was produced; the dehydrogenation reaction was also proved by the elemental analysis and HHV results. The pour point of the final liquid product met the requirement.

  13. Target Product Profile for a Diagnostic Assay to Differentiate between Bacterial and Non-Bacterial Infections and Reduce Antimicrobial Overuse in Resource-Limited Settings: An Expert Consensus.

    Directory of Open Access Journals (Sweden)

    Sabine Dittrich

    Full Text Available Acute fever is one of the most common presenting symptoms globally. In order to reduce the empiric use of antimicrobial drugs and improve outcomes, it is essential to improve diagnostic capabilities. In the absence of microbiology facilities in low-income settings, an assay to distinguish bacterial from non-bacterial causes would be a critical first step. To ensure that patient and market needs are met, the requirements of such a test should be specified in a target product profile (TPP. To identify minimal/optimal characteristics for a bacterial vs. non-bacterial fever test, experts from academia and international organizations with expertise in infectious diseases, diagnostic test development, laboratory medicine, global health, and health economics were convened. Proposed TPPs were reviewed by this working group, and consensus characteristics were defined. The working group defined non-severely ill, non-malaria infected children as the target population for the desired assay. To provide access to the most patients, the test should be deployable to community health centers and informal health settings, and staff should require 90% and >80% for sensitivity and specificity, respectively. Other key characteristics, to account for the challenging environment at which the test is targeted, included: i time-to-result <10 min (but maximally <2 hrs; ii storage conditions at 0-40°C, ≤90% non-condensing humidity with a minimal shelf life of 12 months; iii operational conditions of 5-40°C, ≤90% non-condensing humidity; and iv minimal sample collection needs (50-100μL, capillary blood. This expert approach to define assay requirements for a bacterial vs. non-bacterial assay should guide product development, and enable targeted and timely efforts by industry partners and academic institutions.

  14. Novel approach for the use of dairy industry wastes for bacterial growth media production.

    Science.gov (United States)

    Kasmi, Mariam; Elleuch, Lobna; Dahmeni, Ameni; Hamdi, Moktar; Trabelsi, Ismail; Snoussi, Mejdi

    2018-04-15

    This work proposes a novel approach for the reuse and the recovery of dairy wastes valuable components. Thermal coagulation was performed for dairy effluents and the main responsible fraction for the organic matter content (protein and fat) was separated. Dairy curds were prepared for the formulation of bacterial growth media. Protein, sugar, fat and fatty acids contents have been assessed. Samples treated at 100 °C exhibited marked improvement in terms of protein (25-50%) recovery compared to those treated at 80 °C. Fatty acid analysis revealed the presence of unsaturated fatty acids (mainly oleic acid) that are essential to promote Lactobacillus growth. Previously isolated and identified bacterial strains from dairy wastes (Lactobacillus paracasei, Lactobacillus plantarum, Lactococcus lactis and Lactobacillus brevis) were investigated for their ability to grow on the formulated media. All the tested lactic acid bacteria exhibited greater bacterial growth on the formulated media supplemented with glucose only or with both glucose and yeast extract compared to the control media. By reference to the commercial growth medium, the productivity ratio of the supplemented bactofugate (B) and decreaming (D) formulated media exceeded 0.6 for L. paracasei culture. Whereas, the productivity ratio of the supplemented B medium was greater than 1 compared to the control medium for all the tested strains. As for the supplemented D medium, its productivity ratio was greater than 1 compared to the control medium for both L. paracasei and L. plantarum strains. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Condensed tannins affect bacterial and fungal microbiomes and mycotoxin production during ensiling and upon aerobic exposure.

    Science.gov (United States)

    Peng, Kai; Jin, Long; Niu, Yan D; Huang, Qianqian; McAllister, Tim A; Yang, Hee Eun; Denise, Hubert; Xu, Zhongjun; Acharya, Surya; Wang, Shunxi; Wang, Yuxi

    2017-12-15

    Purple prairie clover (PPC; Dalea purpurea Vent.) containing 84.5 g/kg DM of condensed tannin (CT) was ensiled without (Control) or with polyethylene glycol (PEG) for 76 days, followed by 14 days of aerobic exposure. Changes in fermentation characteristics were determined and bacterial and fungal communities were assessed using metagenomic sequencing. Addition of PEG that deactivated CT at ensiling increased ( P aerobic exposure. The PEG treated silage exhibited higher ( P aerobic exposure, whereas it increased ( P aerobic exposure. Addition of PEG at ensiling increased ( P aerobic exposure, whereas the Bacillus were the dominate bacteria after aerobic exposure. In conclusion, CT decreased protein degradation and improved aerobic stability of silage. These desirable outcomes likely reflect the ability of PPC CT to inhibit those microorganisms involved in lowering silage quality and in the production of mycotoxins. IMPORTANCE The present study reports the effects of condensed tannins on the complex microbial communities involved in ensiling and aerobic exposure of purple prairie clover. This study documents the ability of condensed tannins to lower mycotoxin production and associated microbiome. Taxonomic bacterial community profiles were dominated by the Lactobacillales after fermentation, with a notable increase in Bacillus as a result of aerobic exposure. It is interesting to observe that condensed tannins decreased bacterial diversity during both ensiling and aerobic exposure but increased fungal diversity during aerobic exposure only. The present study indicates that the effects of condensed tannins on microbial communities lead to a reduced lactic acid and total volatile fatty acids production, proteolysis and mycotoxin concentration in the terminal silage and an improved aerobic stability. Condensed tannins could be used as additive to control unfavorable microbial development and maybe enhanced feed safety. © Crown copyright 2017.

  16. Contribution of heterotrophic bacterial production to the carbon budget of the river Seine (France).

    Science.gov (United States)

    Servais, P; Garnier, J

    1993-01-01

    Bacterial activity was measured in the river Seine by two methods, (3)H-thymidine incorporation into DNA and (3)H-leucine incorporation into proteins. Both incorporation rates are characterized by low values upstream of Paris, a large increase just downstream of the outfall of the Achères treatment plant effluents, and then decreasing values further downstream. The covariation of both activities is demonstrated by the constancy of the molar ratio (leucine to thymidine incorporation rate) in the range of 6 to 8 for all the samples, except in the perturbed area where it is higher (15 to 35). These high values of molar ratio are linked to the introduction into the river of large sized bacteria ([Symbol: see text]1 µm) with higher incorporation rates per cell or biomass unit than the small autochthonous bacteria (rates of large bacteria were on average 3.7 times higher than those of small bacteria. Bacterial production was calculated with experimentally determined conversion factors (0.5 × 10(18) cells per mole of thymidine incorporated and 900 gC per mole of leucine incorporated) and by taking into account the activity of both size classes of bacteria measured through fractionation experiments (post-incubation filtration). Production estimated in the perturbed area downstream of Ach6res was very high, up to 60 µgC liter(-1)h(-1) in the summer. Carbon consumption by bacteria in the area perturbed by the Ach6res effluents was calculated assuming a growth yield of 0.2 and compared to the load of biodegradable organic matter discharged by the treatment plant. In summer, an additional supply of organic matter is required to account for the intense bacterial activity, suggesting the importance of phytoplankton production in the carbon budget.

  17. Engineering Escherichia coli for Biodiesel Production Utilizing a Bacterial Fatty Acid Methyltransferase▿†

    Science.gov (United States)

    Nawabi, Parwez; Bauer, Stefan; Kyrpides, Nikos; Lykidis, Athanasios

    2011-01-01

    The production of low-cost biofuels in engineered microorganisms is of great interest due to the continual increase in the world's energy demands. Biodiesel is a renewable fuel that can potentially be produced in microbes cost-effectively. Fatty acid methyl esters (FAMEs) are a common component of biodiesel and can be synthesized from either triacylglycerol or free fatty acids (FFAs). Here we report the identification of a novel bacterial fatty acid methyltransferase (FAMT) that catalyzes the formation of FAMEs and 3-hydroxyl fatty acid methyl esters (3-OH-FAMEs) from the respective free acids and S-adenosylmethionine (AdoMet). FAMT exhibits a higher specificity toward 3-hydroxy free fatty acids (3-OH-FFAs) than FFAs, synthesizing 3-hydroxy fatty acid methyl esters (3-OH-FAMEs) in vivo. We have also identified bacterial members of the fatty acyl-acyl carrier protein (ACP) thioesterase (FAT) enzyme family with distinct acyl chain specificities. These bacterial FATs exhibit increased specificity toward 3-hydroxyacyl-ACP, generating 3-OH-FFAs, which can subsequently be utilized by FAMTs to produce 3-OH-FAMEs. PhaG (3-hydroxyacyl ACP:coenzyme A [CoA] transacylase) constitutes an alternative route to 3-OH-FFA synthesis; the coexpression of PhaG with FAMT led to the highest level of accumulation of 3-OH-FAMEs and FAMEs. The availability of AdoMet, the second substrate for FAMT, is an important factor regulating the amount of methyl esters produced by bacterial cells. Our results indicate that the deletion of the global methionine regulator metJ and the overexpression of methionine adenosyltransferase result in increased methyl ester synthesis. PMID:21926202

  18. wax matrix tablets and its implication on dissolution prof

    African Journals Online (AJOL)

    acetaminophen-wax matrix tablet and hence its implication on dissolution profile. Acetaminophen-wax ... inertness, cost effectiveness, non- toxicity and more importantly their ... Liver Poole, England) at constant load (30 arbitrary units on the ...

  19. Seaweed as source of energy. 1: effect of a specific bacterial strain on biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Sreenivasa R.P.; Tarwade, S.J.; Sarma, K.S.R.

    1980-09-01

    Only certain marine bacteria capable of digesting the special type of polysaccharide - agar and alginic acid can bring about the biodegradation of these substances and utilise them as carbon source to produce the organics which will be utilised by the methane bacteria to produce methane. When bacterial strain was used in conjunction with cowdung as a source of methane bacteria in seaweed digester, production of biogas from seaweed was accelerated. Adding of small amount of Ulva to seaweed digester increased the output of gas. (Refs. 4).

  20. Estimating Bacterial Production in Marine Waters from the Simultaneous Incorporation of Thymidine and Leucine

    OpenAIRE

    Chin-Leo, Gerardo; Kirchman, David L.

    1988-01-01

    We examined the simultaneous incorporation of [3H]thymidine and [14C]leucine to obtain two independent indices of bacterial production (DNA and protein syntheses) in a single incubation. Incorporation rates of leucine estimated by the dual-label method were generally higher than those obtained by the single-label method, but the differences were small (dual/single = 1.1 ± 0.2 [mean ± standard deviation]) and were probably due to the presence of labeled leucyl-tRNA in the cold trichloroacetic ...

  1. Review of data on the dermal penetration of mineral oils and waxes used in cosmetic applications.

    Science.gov (United States)

    Petry, T; Bury, D; Fautz, R; Hauser, M; Huber, B; Markowetz, A; Mishra, S; Rettinger, K; Schuh, W; Teichert, T

    2017-10-05

    Mineral oils and waxes used in cosmetic products, also referred to as "personal care products" outside the European Union, are mixtures of predominantly saturated hydrocarbons consisting of straight-chain, branched and ring structures with carbon chain lengths greater than C16. They are used in skin and lip care cosmetic products due to their excellent skin tolerance as well as their high protecting and cleansing performance and broad viscosity options. Recently, concerns have been raised regarding potential adverse health effects of mineral oils and waxes from dermal application of cosmetics. In order to be able to assess the risk for the consumer the dermal penetration potential of these ingredients has to be evaluated. The scope and objective of this review are to identify and summarize publicly available literature on the dermal penetration of mineral oils and waxes as used in cosmetic products. For this purpose, a comprehensive literature search was conducted. A total of 13 in vivo (human, animal) and in vitro studies investigating the dermal penetration of mineral oils and waxes has been identified and analysed. The majority of the substances were dermally adsorbed to the stratum corneum and only a minor fraction reached deeper skin layers. Overall, there is no evidence from the various studies that mineral oils and waxes are percutaneously absorbed and become systemically available. Thus, given the absence of dermal uptake, mineral oils and waxes as used in cosmetic products do not present a risk to the health of the consumer. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Effects of air pollutants on epicuticular wax structure

    International Nuclear Information System (INIS)

    Huttunen, S.

    1994-01-01

    In xerophytes, like conifers, the epicuticular wax is well developed. Especially in and around stomatal entrances, a thick wax coating is present. Epicuticular waxes are modified by changes in plant growth conditions such as temperature, relative humidity, irradiance, and wind, or acid rain. The fine structure of epicuticular waxes, their chemistry, and ecophysiological function are modified, especially in evergreen, long-lived conifer needles with characteristic crystalline wax structures. During needle flushing and development, wax structure is easily modified. Acid rain-treated Scots pine needles had 50% less epicuticular waxes in early August. Pollution-induced delayed development, destruction, and disturbances have been identified in many plant species. The structural changes in wax crystals are known. Acid rain or polluted air can destroy the crystalloid epicuticular waxes in a few weeks. In Pinus sylvestris, the first sign of pollution effect is the fusion of wax tubes. In Picea abies and P. sitchensis, modifications of crystalloid wax structure are known. In Californian pine trees phenomena of recrystallization of wax tubes on second-year needles were observed after delayed epicuticular wax development in Pinus ponderosa and P. coulteri. Thus, the effects of air pollutants are modified by climate. Accelerated senescence of leaves and needles have been associated with natural and anthropogenic stresses. The accelerated erosion rate of epicuticular waxes has been measured under air pollution conditions. Many short-term air pollution experiments have failed to show any structural changes in epicuticular wax structures. The quantity and quality of needle waxes grown in open-top chambers, glass houses, or polluted air before treatment, differ from field conditions and make it difficult to detect effects of any treatment. (orig.)

  3. Dental students' preferences and performance in crown design: conventional wax-added versus CAD.

    Science.gov (United States)

    Douglas, R Duane; Hopp, Christa D; Augustin, Marcus A

    2014-12-01

    The purpose of this study was to evaluate dental students' perceptions of traditional waxing vs. computer-aided crown design and to determine the effectiveness of either technique through comparative grading of the final products. On one of twoidentical tooth preparations, second-year students at one dental school fabricated a wax pattern for a full contour crown; on the second tooth preparation, the same students designed and fabricated an all-ceramic crown using computer-aided design (CAD) and computer-aided manufacturing (CAM) technology. Projects were graded for occlusion and anatomic form by three faculty members. On completion of the projects, 100 percent of the students (n=50) completed an eight-question, five-point Likert scalesurvey, designed to assess their perceptions of and learning associated with the two design techniques. The average grades for the crown design projects were 78.3 (CAD) and 79.1 (wax design). The mean numbers of occlusal contacts were 3.8 (CAD) and 2.9(wax design), which was significantly higher for CAD (p=0.02). The survey results indicated that students enjoyed designing afull contour crown using CAD as compared to using conventional wax techniques and spent less time designing the crown using CAD. From a learning perspective, students felt that they learned more about position and the size/strength of occlusal contacts using CAD. However, students recognized that CAD technology has limits in terms of representing anatomic contours and excursive occlusion compared to conventional wax techniques. The results suggest that crown design using CAD could be considered as an adjunct to conventional wax-added techniques in preclinical fixed prosthodontic curricula.

  4. Bacterial cellulose production by Gluconacetobacter xylinus by employing alternative culture media.

    Science.gov (United States)

    Jozala, Angela Faustino; Pértile, Renata Aparecida Nedel; dos Santos, Carolina Alves; de Carvalho Santos-Ebinuma, Valéria; Seckler, Marcelo Martins; Gama, Francisco Miguel; Pessoa, Adalberto

    2015-02-01

    Bacterial cellulose (BC) is used in different fields as a biological material due to its unique properties. Despite there being many BC applications, there still remain many problems associated with bioprocess technology, such as increasing productivity and decreasing production cost. New technologies that use waste from the food industry as raw materials for culture media promote economic advantages because they reduce environmental pollution and stimulate new research for science sustainability. For this reason, BC production requires optimized conditions to increase its application. The main objective of this study was to evaluate BC production by Gluconacetobacter xylinus using industry waste, namely, rotten fruits and milk whey, as culture media. Furthermore, the structure of BC produced at different conditions was also determined. The culture media employed in this study were composed of rotten fruit collected from the disposal of free markets, milk whey from a local industrial disposal, and their combination, and Hestrin and Schramm media was used as standard culture media. Although all culture media studied produced BC, the highest BC yield-60 mg/mL-was achieved with the rotten fruit culture. Thus, the results showed that rotten fruit can be used for BC production. This culture media can be considered as a profitable alternative to generate high-value products. In addition, it combines environmental concern with sustainable processes that can promote also the reduction of production cost.

  5. 75 FR 63200 - Petroleum Wax Candles From China

    Science.gov (United States)

    2010-10-14

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-282 (Third Review)] Petroleum Wax Candles... five-year review concerning the antidumping duty order on petroleum wax candles from China. SUMMARY... antidumping duty order on petroleum wax candles from China would be likely to lead to continuation or...

  6. 75 FR 80843 - Petroleum Wax Candles From China

    Science.gov (United States)

    2010-12-23

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-282 (Third Review)] Petroleum Wax Candles... Tariff Act of 1930 (19 U.S.C. 1675(c)), that revocation of the antidumping duty order on petroleum wax... contained in USITC Publication 4207 (December 2010), entitled Petroleum Wax Candles from China...

  7. Effects of aromatic compounds on the production of bacterial nanocellulose by Gluconacetobacter xylinus.

    Science.gov (United States)

    Zhang, Shuo; Winestrand, Sandra; Guo, Xiang; Chen, Lin; Hong, Feng; Jönsson, Leif J

    2014-04-30

    Bacterial cellulose (BC) is a polymeric nanostructured fibrillar network produced by certain microorganisms, principally Gluconacetobacter xylinus. BC has a great potential of application in many fields. Lignocellulosic biomass has been investigated as a cost-effective feedstock for BC production through pretreatment and hydrolysis. It is well known that detoxification of lignocellulosic hydrolysates may be required to achieve efficient production of BC. Recent results suggest that phenolic compounds contribute to the inhibition of G. xylinus. However, very little is known about the effect on G. xylinus of specific lignocellulose-derived inhibitors. In this study, the inhibitory effects of four phenolic model compounds (coniferyl aldehyde, ferulic acid, vanillin and 4-hydroxybenzoic acid) on the growth of G. xylinus, the pH of the culture medium, and the production of BC were investigated in detail. The stability of the phenolics in the bacterial cultures was investigated and the main bioconversion products were identified and quantified. Coniferyl aldehyde was the most potent inhibitor, followed by vanillin, ferulic acid, and 4-hydroxybenzoic acid. There was no BC produced even with coniferyl aldehyde concentrations as low as 2 mM. Vanillin displayed a negative effect on the bacteria and when the vanillin concentration was raised to 2.5 mM the volumetric yield of BC decreased to ~40% of that obtained in control medium without inhibitors. The phenolic acids, ferulic acid and 4-hydroxybenzoic acid, showed almost no toxic effects when less than 2.5 mM. The bacterial cultures oxidized coniferyl aldehyde to ferulic acid with a yield of up to 81%. Vanillin was reduced to vanillyl alcohol with a yield of up to 80%. This is the first investigation of the effect of specific phenolics on the production of BC by G. xylinus, and is also the first demonstration of the ability of G. xylinus to convert phenolic compounds. This study gives a better understanding of how

  8. 21 CFR 172.886 - Petroleum wax.

    Science.gov (United States)

    2010-04-01

    ... availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register... it is very hygroscopic and will react with some metal containers in the presence of air. Phosphoric... high enough to keep the wax melted. (Note: In preheating the sulfoxide-acid mixture, remove the stopper...

  9. Particulate organic matter predicts bacterial productivity in a river dominated estuary

    Science.gov (United States)

    Crump, B. C.

    2015-12-01

    Estuaries act as coastal filters for organic and inorganic fluvial materials in which microbial, biogeochemical, and ecological processes combine to transform organic matter and nutrients prior to export to the coastal ocean. The function of this estuarine 'bioreactor' is linked to the residence times of those materials and to rates of microbial heterotrophic activity. Our ability to forecast the impact of global change on estuarine bioreactor function requires an understanding of the basic controls on microbial community activity and diversity. In the Columbia River estuary, the microbial community undergoes a dramatic seasonal shift in species composition during which a spring bacterioplankton community, dominated by Flavobacteriaceae and Oceanospirillales, is replaced by a summer community, dominated by Rhodobacteraceae and several common marine taxa. This annual shift occurs in July, following the spring freshet, when river flow and river chlorophyll concentration decrease and when estuarine water residence time increases. Analysis of a large dataset from 17 research cruises (1990-2014) showed that the composition of particulate organic matter in the estuary changes after the freshet with decreasing organic carbon and nitrogen content, and increasing contribution of marine and autochthonous estuarine organic matter (based on PO13C and pigment ratios). Bacterial production rates (measured as leucine or thymidine incorporation rates) in the estuary respond to this change, and correlate strongly with labile particulate nitrogen concentration and temperature during individual sampling campaigns, and with the concentration of chlorophyll in the Columbia River across all seasons. Regression models suggest that the concentration of labile particulate nitrogen and the rate of bacterial production can be predicted from sensor measurements of turbidity, salinity, and temperature in the estuary and chlorophyll in the river. These results suggest that the quality of

  10. Bacterial production determined by [3H]thymidine incorporation in field rhizospheres as evaluated by comparison to rhizodeposition

    DEFF Research Database (Denmark)

    Christensen, Henrik; Rønn, Regin; Ekelund, Flemming

    1995-01-01

    In a sandy loam soil cropped to barley bacterial production in the rhizosphere was compared to the results of a parallel investigation on rhizodeposition. Bacterial production was stimulated in the rhizosphere as revealed by an increased biomass of bacteria (643–883 µg C g-1 soil) and protozoa (7.......2–15 × 104 cells g-1 soil) as well as elevated thymidine incorporation (9.7–12 pmol g-1 soil) in rhizosphere soil compared to bulk soil. Rhizodeposition, as determined by several pulse labellings with 14CO2, was estimated to be 412 µg C g-1 dry wt soil in the 0–15 cm layer. Bacterial production......, as determined by incorporation of 3H-labelled thymidine converted to bacterial C, revealed a plant-induced formation of 1348 µg bacterial C g-1 soil in the 0–15 cm layer. This is probably the first estimate for bacterial production based on thymidine incorporation which has been compared to an estimate of C...

  11. Methane Production in Dairy Cows Correlates with Rumen Methanogenic and Bacterial Community Structure.

    Science.gov (United States)

    Danielsson, Rebecca; Dicksved, Johan; Sun, Li; Gonda, Horacio; Müller, Bettina; Schnürer, Anna; Bertilsson, Jan

    2017-01-01

    Methane (CH 4 ) is produced as an end product from feed fermentation in the rumen. Yield of CH 4 varies between individuals despite identical feeding conditions. To get a better understanding of factors behind the individual variation, 73 dairy cows given the same feed but differing in CH 4 emissions were investigated with focus on fiber digestion, fermentation end products and bacterial and archaeal composition. In total 21 cows (12 Holstein, 9 Swedish Red) identified as persistent low, medium or high CH 4 emitters over a 3 month period were furthermore chosen for analysis of microbial community structure in rumen fluid. This was assessed by sequencing the V4 region of 16S rRNA gene and by quantitative qPCR of targeted Methanobrevibacter groups. The results showed a positive correlation between low CH 4 emitters and higher abundance of Methanobrevibacter ruminantium clade. Principal coordinate analysis (PCoA) on operational taxonomic unit (OTU) level of bacteria showed two distinct clusters ( P microbial population or host genetic differences that is reflected in bacterial and archaeal (or methanogens) populations.

  12. Effect of grazers and viruses on bacterial community structure and production in two contrasting trophic lakes

    Directory of Open Access Journals (Sweden)

    Domaizon Isabelle

    2011-04-01

    Full Text Available Abstract Background Over the last 30 years, extensive studies have revealed the crucial roles played by microbes in aquatic ecosystems. It has been shown that bacteria, viruses and protozoan grazers are dominant in terms of abundance and biomass. The frequent interactions between these microbiological compartments are responsible for strong trophic links from dissolved organic matter to higher trophic levels, via heterotrophic bacteria, which form the basis for the important biogeochemical roles of microbial food webs in aquatic ecosystems. To gain a better understanding of the interactions between bacteria, viruses and flagellates in lacustrine ecosystems, we investigated the effect of protistan bacterivory on bacterial abundance, production and structure [determined by 16S rRNA PCR-DGGE], and viral abundance and activity of two lakes of contrasting trophic status. Four experiments were conducted in the oligotrophic Lake Annecy and the mesotrophic Lake Bourget over two seasons (early spring vs. summer using a fractionation approach. In situ dark vs. light incubations were performed to consider the effects of the different treatments in the presence and absence of phototrophic activity. Results The presence of grazers (i.e. Conclusions Our results highlight the importance of a synergistic effect, i.e. the positive influence of grazers on viral activities in sustaining (directly and indirectly bacterial production and affecting composition, in both oligotrophic and mesotrophic lakes.

  13. Mass production of bacterial communities adapted to the degradation of volatile organic compounds (TEX).

    Science.gov (United States)

    Lapertot, Miléna; Seignez, Chantal; Ebrahimi, Sirous; Delorme, Sandrine; Peringer, Paul

    2007-06-01

    This study focuses on the mass cultivation of bacteria adapted to the degradation of a mixture composed of toluene, ethylbenzene, o-, m- and p-xylenes (TEX). For the cultivation process Substrate Pulse Batch (SPB) technique was adapted under well-automated conditions. The key parameters to be monitored were handled by LabVIEW software including, temperature, pH, dissolved oxygen and turbidity. Other parameters, such as biomass, ammonium or residual substrate concentrations needed offline measurements. SPB technique has been successfully tested experimentally on TEX. The overall behavior of the mixed bacterial population was observed and discussed along the cultivation process. Carbon and nitrogen limitations were shown to affect the integrity of the bacterial cells as well as their production of exopolymeric substances (EPS). Average productivity and yield values successfully reached the industrial specifications, which were 0.45 kg(DW)m(-3) d(-1) and 0.59 g(DW)g (C) (-1) , respectively. Accuracy and reproducibility of the obtained results present the controlled SPB process as a feasible technique.

  14. Fed-Batch Production of Bacterial Ghosts Using Dielectric Spectroscopy for Dynamic Process Control

    Directory of Open Access Journals (Sweden)

    Andrea Meitz

    2016-03-01

    Full Text Available The Bacterial Ghost (BG platform technology evolved from a microbiological expression system incorporating the ϕX174 lysis gene E. E-lysis generates empty but structurally intact cell envelopes (BGs from Gram-negative bacteria which have been suggested as candidate vaccines, immunotherapeutic agents or drug delivery vehicles. E-lysis is a highly dynamic and complex biological process that puts exceptional demands towards process understanding and control. The development of a both economic and robust fed-batch production process for BGs required a toolset capable of dealing with rapidly changing concentrations of viable biomass during the E-lysis phase. This challenge was addressed using a transfer function combining dielectric spectroscopy and soft-sensor based biomass estimation for monitoring the rapid decline of viable biomass during the E-lysis phase. The transfer function was implemented to a feed-controller, which followed the permittivity signal closely and was capable of maintaining a constant specific substrate uptake rate during lysis phase. With the described toolset, we were able to increase the yield of BG production processes by a factor of 8–10 when compared to currently used batch procedures reaching lysis efficiencies >98%. This provides elevated potentials for commercial application of the Bacterial Ghost platform technology.

  15. Cellulosic hydrogen production with a sequencing bacterial hydrolysis and dark fermentation strategy.

    Science.gov (United States)

    Lo, Yung-Chung; Bai, Ming-Der; Chen, Wen-Ming; Chang, Jo-Shu

    2008-11-01

    In this study, cellulose hydrolysis activity of two mixed bacterial consortia (NS and QS) was investigated. Combination of NS culture and BHM medium exhibited better hydrolytic activity under the optimal condition of 35 degrees C, initial pH 7.0, and 100rpm agitation. The NS culture could hydrolyze carboxymethyl cellulose (CMC), rice husk, bagasse and filter paper, among which CMC gave the best hydrolysis performance. The CMC hydrolysis efficiency increased with increasing CMC concentration from 5 to 50g/l. With a CMC concentration of 10g/l, the total reducing sugar (RS) production and the RS producing rate reached 5531.0mg/l and 92.9mg/l/h, respectively. Furthermore, seven H2-producing bacterial isolates (mainly Clostridium species) were used to convert the cellulose hydrolysate into H2 energy. With an initial RS concentration of 0.8g/l, the H2 production and yield was approximately 23.8ml/l and 1.21mmol H2/g RS (0.097mmol H2/g cellulose), respectively.

  16. EFFECT OF REFINED PETROLEUM PRODUCTS CONTAMINATION ON BACTERIAL POPULATION AND PHYSICOCHEMICAL CHARACTERISTICS OF CULTIVATED AGRICULTURAL SOIL

    Directory of Open Access Journals (Sweden)

    Adewale Sogo Olalemi

    2012-10-01

    Full Text Available An investigation into the effect of refined petroleum products contamination on bacterial population and physicochemical characteristics of cultivated agricultural soil was carried out. The soil samples obtained from the Teaching and Research Farm, Obakekere, Federal University of Technology, Akure, Ondo State were contaminated with varying volumes of petrol, diesel and kerosene. The results revealed higher bacterial populations in uncontaminated soils than contaminated soils. The counts of bacteria ranged from 3.0 × 105 to 5.0 × 105 cfu/g in uncontaminated soils and 1.0 × 105 to 3.0 × 105 cfu/g in contaminated soils. The isolated bacteria were identified as Bacillus subtilis, Flavobacterium lutescens, Micrococcus luteus, Corynebacterium variabilis, Pseudomonas fluorescens. The contamination had no significant effect on pH, potassium, sodium, organic carbon and nitrogen content of the soils, while the moisture, calcium, phosphorus and magnesium content of the contaminated soils were significantly different (P < 0.05 compared with the uncontaminated soils. The ability of Bacillus subtilis, Flavobacterium lutescens, Micrococcus luteus, and Pseudomonas fluorescens to utilize the refined petroleum products suggest that these bacteria had potential to bioremediate petroleum contaminated soils.

  17. Macrophage activation induced by Brucella DNA suppresses bacterial intracellular replication via enhancing NO production.

    Science.gov (United States)

    Liu, Ning; Wang, Lin; Sun, Changjiang; Yang, Li; Tang, Bin; Sun, Wanchun; Peng, Qisheng

    2015-12-01

    Brucella DNA can be sensed by TLR9 on endosomal membrane and by cytosolic AIM2-inflammasome to induce proinflammatory cytokine production that contributes to partially activate innate immunity. Additionally, Brucella DNA has been identified to be able to act as a major bacterial component to induce type I IFN. However, the role of Brucella DNA in Brucella intracellular growth remains unknown. Here, we showed that stimulation with Brucella DNA promote macrophage activation in TLR9-dependent manner. Activated macrophages can suppresses wild type Brucella intracellular replication at early stage of infection via enhancing NO production. We also reported that activated macrophage promotes bactericidal function of macrophages infected with VirB-deficient Brucella at the early or late stage of infection. This study uncovers a novel function of Brucella DNA, which can help us further elucidate the mechanism of Brucella intracellular survival. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Isolasi, Seleksi Dan Opttmasi Produksi Protease Daribeberapaisolat Bakteri*(isolation, Selection and Optimalization of Protease Production of Some Bacterial Isolates)

    OpenAIRE

    Naiola, Elidar; Widhyastuti, Nunuk

    2002-01-01

    Thirty-seven out of sixty-one bacterial isolates from various sources of samples were screened for protease production. The isolate of ISO PL3 could produce the highest enzyme activity, and it was used as a standard bacterial strain in this observation. For any reason,we implemented ISO PL2 to study the optimum condition for producing bacterial protease. Result shows that the maximum protease activity was obtained in a medium containing 100 gram of rice brand in a liter tofu liquid waste. The...

  19. Bacterial Standing Stock, Activity, and Carbon Production during Formation and Growth of Sea Ice in the Weddell Sea, Antarctica †

    OpenAIRE

    Grossmann, Sönnke; Dieckmann, Gerhard S.

    1994-01-01

    Bacterial response to formation and growth of sea ice was investigated during autumn in the northeastern Weddell Sea. Changes in standing stock, activity, and carbon production of bacteria were determined in successive stages of ice development. During initial ice formation, concentrations of bacterial cells, in the order of 1 × 108 to 3 × 108 liter-1, were not enhanced within the ice matrix. This suggests that physical enrichment of bacteria by ice crystals is not effective. Due to low conce...

  20. ETHNOECOLOGY AND ETHNOBOTANY OF THE PALM CARNAUBA WAX IN BRAZILIAN SEMI-ARID

    Directory of Open Access Journals (Sweden)

    Rodrigo Ferreira de Sousa

    2015-12-01

    Full Text Available The aim of this study was to investigate aspects of ethnoecological and ethnobotanical of carnauba wax (Copernicia prunifera (Miller H. E. Moore, Arecaceae in an extractive community of municipality of Ipanguaçu, Rio Grande do Norte state. We interviewed key informants, using the technique of inducing nonspecific, guided tour and direct observation to confirm the data. According to most residents of Pedro Ezequiel Araújo community, the area of carnauba wax in the region is natural. In the research ethnoecological, 73% of informants reported the occurrence of “a different kind of carnauba”, known as “white carnauba” phenotypically distinct from the “common carnauba wax” by presenting clear stipe, smaller fruits and absence of spines on the petiole, and is rare at the study site. Much of the informants observed phenological phases of carnauba wax, being consistent in stating that the species has fruits dispersed by bats. In ethnobotany, powder wax was cited by all as the most important product extracted from leaves of carnauba and the most used, followed by fruit, stem and root. Were still reported the division of work in the extraction of powder wax from the carnauba. The results of this research will contribute to knowledge of ethnobotanical and ethnoecological carnauba, supporting strategies for management and conservation of natural populations.

  1. Biodegradation of paraffin wax by crude Aspergillus enzyme preparations for potential use in removing paraffin deposits.

    Science.gov (United States)

    Zhang, Junhui; Xue, Quanhong; Gao, Hui; Wang, Ping

    2015-11-01

    Paraffin deposition problems have plagued the oil industry. Whist mechanical and chemical methods are problematic, microbiological method of paraffin removal is considered an alternative. However, studies have mainly investigated the use of bacteria, with little attention to the potential of fungi. The performance of six Aspergillus isolates to degrade paraffin wax was evaluated under laboratory conditions using solid enzyme preparations. The results showed that all the six enzyme preparations efficiently improved the solubility of paraffin wax in n-hexane and degraded n-alkanes in paraffin wax. The degradation process was accompanied by dynamic production of gases (CO2 and H2 ) and organic acids (oxalate and propionate). The shape of wax crystals markedly changed after enzymatic degradation, with a rough surface and a loose structure. This study indicates that extracellular enzymes from Aspergillus spp. can efficiently degrade paraffin wax. These enzyme preparations have the potential for use in oil wells with paraffin deposition problems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Chemical composition of raw and deresinated peat waxes

    Energy Technology Data Exchange (ETDEWEB)

    Bel' kevich, P I; Ivanova, L A; Piskunova, T A; Tserlyukevich, Ya V; Yurkevich, E A

    1980-01-01

    Research was conducted using absorption chromatography and spectroscopy to study the changes in the chemical composition of raw peat wax taking place in the deresination process. Characteristics of the raw, deresinated waxes and resins removed are given. The fractions obtained showed that both raw and deresinated wax contain the same basic compound classes: hydrocarbons, alcohols, complex ether and acids; but their proportions in the waxes are different. After deresination most of the dark-colored polyfunctional compounds, a portion of the soluble unsaturated hydrocarbons and alcohols, and all the sterenes transfer into the resin. This causes the light color and specific physical properties of deresinated wax. (13 refs.) (In Russian)

  3. Use of metabolic inhibitors to estimate protozooplankton grazing and bacterial production in a monomictic eutrophic lake with an anaerobic hypolimnion

    International Nuclear Information System (INIS)

    Sanders, R.W.; Porter, K.G.

    1986-01-01

    Inhibitors of eucaryotes (cycloheximide and amphotericin B) and procaryotes (penicillin and chloramphenical) were used to estimate bacterivory and bacterial production in a eutrophic lake. Bacterial production appeared to be slightly greater than protozoan grazing in the aerobic waters of Lake Oglethorpe. Use of penicillin and cycloheximide yielded inconsistent results in anaerobic water and in aerobic water when bacterial production was low. Production measured by inhibiting eucaryotes with cycloheximide did not always agree with [ 3 H]thymidine estimates or differential filtration methods. Laboratory experiments showed that several common freshwater protozoans continued to swim and ingest bacterium-size latex beads in the presence of the eucaryote inhibitor. Penicillin also affected grazing rates of some ciliates. The authors recommended that caution and a corroborating method be used when estimating ecologically important parameters with specific inhibitors

  4. Factors influencing production of lipase under metal supplementation by bacterial strain, Bacillus subtilis BDG-8.

    Science.gov (United States)

    Dhevahi, B; Gurusamy, R

    2014-11-01

    Lipases are biocatalyst having wide applications in industries due to their versatile properties. In the present study, a lipolytic bacterial strain, Bacillus subtilis BDG-8 was isolated from an oil based industrial soil. The effect of selenium and nickel as a media supplement on enhancement of lipase production, was studied individually with the isolated strain by varying the concentration of selected metal. 60 μg l(-1) selenium enhanced lipase production to an enzyme activity measuring 7.8 U ml(-1) while 40 μgI(-1) nickel gave the maximum enzyme activity equivalent to 7.5 U ml(-1). However, nickel and selenium together at a range of concentration with an equal w/v ratio, at 60 μg l(-1) each, showed the maximum lipase activity of 8.5 U ml(-1). The effect of pH and temperature on lipase production showed maximum enzyme activity in the presence of each of the metals at pH 7 and 35°C among the other tested ranges. After optimisation of the parameters such as metal concentration, pH and temperature lipase production by Bacillus subtilis BDG-8 had increased several folds. This preliminary investigation may consequently lead as to various industrial applications such as treatment of wastewater contaminated with metal or oil with simultaneous lipase production.

  5. Limited Bacterial Diversity within a Treatment Plant Receiving Antibiotic-Containing Waste from Bulk Drug Production

    Science.gov (United States)

    Shouche, Yogesh S.; Larsson, D. G. Joakim

    2016-01-01

    Biological treatment of waste water from bulk drug production, contaminated with high levels of fluoroquinolone antibiotics, can lead to massive enrichment of antibiotic resistant bacteria, resistance genes and associated mobile elements, as previously shown. Such strong selection may be boosted by the use of activated sludge (AS) technology, where microbes that are able to thrive on the chemicals within the wastewater are reintroduced at an earlier stage of the process to further enhance degradation of incoming chemicals. The microbial community structure within such a treatment plant is, however, largely unclear. In this study, Illumina-based 16S rRNA amplicon sequencing was applied to investigate the bacterial communities of different stages from an Indian treatment plant operated by Patancheru Environment Technology Limited (PETL) in Hyderabad, India. The plant receives waste water with high levels of fluoroquinolones and applies AS technology. A total of 1,019,400 sequences from samples of different stages of the treatment process were analyzed. In total 202, 303, 732, 652, 947 and 864 operational taxonomic units (OTUs) were obtained at 3% distance cutoff in the equilibrator, aeration tanks 1 and 2, settling tank, secondary sludge and old sludge samples from PETL, respectively. Proteobacteria was the most dominant phyla in all samples with Gammaproteobacteria and Betaproteobacteria being the dominant classes. Alcaligenaceae and Pseudomonadaceae, bacterial families from PETL previously reported to be highly multidrug resistant, were the dominant families in aeration tank samples. Despite regular addition of human sewage (approximately 20%) to uphold microbial activity, the bacterial diversity within aeration tanks from PETL was considerably lower than corresponding samples from seven, regular municipal waste water treatment plants. The strong selection pressure from antibiotics present may be one important factor in structuring the microbial community in PETL

  6. Limited Bacterial Diversity within a Treatment Plant Receiving Antibiotic-Containing Waste from Bulk Drug Production.

    Science.gov (United States)

    Marathe, Nachiket P; Shetty, Sudarshan A; Shouche, Yogesh S; Larsson, D G Joakim

    2016-01-01

    Biological treatment of waste water from bulk drug production, contaminated with high levels of fluoroquinolone antibiotics, can lead to massive enrichment of antibiotic resistant bacteria, resistance genes and associated mobile elements, as previously shown. Such strong selection may be boosted by the use of activated sludge (AS) technology, where microbes that are able to thrive on the chemicals within the wastewater are reintroduced at an earlier stage of the process to further enhance degradation of incoming chemicals. The microbial community structure within such a treatment plant is, however, largely unclear. In this study, Illumina-based 16S rRNA amplicon sequencing was applied to investigate the bacterial communities of different stages from an Indian treatment plant operated by Patancheru Environment Technology Limited (PETL) in Hyderabad, India. The plant receives waste water with high levels of fluoroquinolones and applies AS technology. A total of 1,019,400 sequences from samples of different stages of the treatment process were analyzed. In total 202, 303, 732, 652, 947 and 864 operational taxonomic units (OTUs) were obtained at 3% distance cutoff in the equilibrator, aeration tanks 1 and 2, settling tank, secondary sludge and old sludge samples from PETL, respectively. Proteobacteria was the most dominant phyla in all samples with Gammaproteobacteria and Betaproteobacteria being the dominant classes. Alcaligenaceae and Pseudomonadaceae, bacterial families from PETL previously reported to be highly multidrug resistant, were the dominant families in aeration tank samples. Despite regular addition of human sewage (approximately 20%) to uphold microbial activity, the bacterial diversity within aeration tanks from PETL was considerably lower than corresponding samples from seven, regular municipal waste water treatment plants. The strong selection pressure from antibiotics present may be one important factor in structuring the microbial community in PETL

  7. Limited Bacterial Diversity within a Treatment Plant Receiving Antibiotic-Containing Waste from Bulk Drug Production.

    Directory of Open Access Journals (Sweden)

    Nachiket P Marathe

    Full Text Available Biological treatment of waste water from bulk drug production, contaminated with high levels of fluoroquinolone antibiotics, can lead to massive enrichment of antibiotic resistant bacteria, resistance genes and associated mobile elements, as previously shown. Such strong selection may be boosted by the use of activated sludge (AS technology, where microbes that are able to thrive on the chemicals within the wastewater are reintroduced at an earlier stage of the process to further enhance degradation of incoming chemicals. The microbial community structure within such a treatment plant is, however, largely unclear. In this study, Illumina-based 16S rRNA amplicon sequencing was applied to investigate the bacterial communities of different stages from an Indian treatment plant operated by Patancheru Environment Technology Limited (PETL in Hyderabad, India. The plant receives waste water with high levels of fluoroquinolones and applies AS technology. A total of 1,019,400 sequences from samples of different stages of the treatment process were analyzed. In total 202, 303, 732, 652, 947 and 864 operational taxonomic units (OTUs were obtained at 3% distance cutoff in the equilibrator, aeration tanks 1 and 2, settling tank, secondary sludge and old sludge samples from PETL, respectively. Proteobacteria was the most dominant phyla in all samples with Gammaproteobacteria and Betaproteobacteria being the dominant classes. Alcaligenaceae and Pseudomonadaceae, bacterial families from PETL previously reported to be highly multidrug resistant, were the dominant families in aeration tank samples. Despite regular addition of human sewage (approximately 20% to uphold microbial activity, the bacterial diversity within aeration tanks from PETL was considerably lower than corresponding samples from seven, regular municipal waste water treatment plants. The strong selection pressure from antibiotics present may be one important factor in structuring the microbial

  8. Light Conditions Affect the Measurement of Oceanic Bacterial Production via Leucine Uptake

    Science.gov (United States)

    Morán, Xosé Anxelu G.; Massana, Ramon; Gasol, Josep M.

    2001-01-01

    The effect of irradiance in the range of 400 to 700 nm or photosynthetically active radiation (PAR) on bacterial heterotrophic production estimated by the incorporation of 3H-leucine (referred to herein as Leu) was investigated in the northwestern Mediterranean Sea and in a coastal North Atlantic site, with Leu uptake rates ranging over 3 orders of magnitude. We performed in situ incubations under natural irradiance levels of Mediterranean samples taken from five depths around solar noon and compared them to incubations in the dark. In two of the three stations large differences were found between light and dark uptake rates for the surfacemost samples, with dark values being on average 133 and 109% higher than in situ ones. Data obtained in coastal North Atlantic waters confirmed that dark enclosure may increase Leu uptake rates more than threefold. To explain these differences, on-board experiments of Leu uptake versus irradiance were performed with Mediterranean samples from depths of 5 and 40 m. Incubations under a gradient of 12 to 1,731 μmol of photons m−2 s−1 evidenced a significant increase in incorporation rates with increasing PAR in most of the experiments, with dark-incubated samples departing from this pattern. These results were not attributed to inhibition of Leu uptake in the light but to enhanced bacterial response when transferred to dark conditions. The ratio of dark to light uptake rates increased as dissolved inorganic nitrogen concentrations decreased, suggesting that bacterial nutrient deficiency was overcome by some process occurring only in the dark bottles. PMID:11525969

  9. Simulation of temperature-pressure profiles and wax deposition in gas-lift wells

    Directory of Open Access Journals (Sweden)

    Sevic Snezana

    2017-01-01

    Full Text Available Gas-lift is an artificial lift method in which gas is injected down the tubing- -casing annulus and enters the production tubing through the gas-lift valves to reduce the hydrostatic pressure of the formation fluid column. The gas changes pressure, temperature and fluid composition profiles throughout the production tubing string. Temperature and pressure drop along with the fluid composition changes throughout the tubing string can lead to wax, asphaltenes and inorganic salts deposition, increased emulsion stability and hydrate formation. This paper presents a new model that can sucesfully simulate temperature and pressure profiles and fluid composition changes in oil well that operates by means of gas-lift. This new model includes a pipe-in-pipe segment (production tubing inside production casing, countercurrent flow of gas-lift gas and producing fluid, heat exchange between gas-lift gas and the surrounding ambient – ground; and gas-lift gas with the fluid in the tubing. The model enables a better understanding of the multiphase fluid flow up the production tubing. Model was used to get insight into severity and locations of wax deposition. The obtained information on wax deposition can be used to plan the frequency and depth of wax removing operations. Model was developed using Aspen HYSYS software.

  10. Effects of air pollutants on epicuticular wax chemical composition

    International Nuclear Information System (INIS)

    Percy, K.E.; McQuattie, C.J.; Rebbeck, J.A.

    1994-01-01

    There are numerous reports in the literature of modifications to epicuticular wax structure as a consequence of exposure to air pollutants. Most authors have used scanning electron microscopy (SEM) to describe changes in wax crystallite morphology or distribution. ''Erosion'' or ''weathering'' of crystalline structure into an amorphous state is the most common observation, particularly in the case of conifer needles having the characteristic tube crystallites comprised of nonacosan-10-ol. Wax structure is largely determined by its chemical composition. Therefore, many of the reported changes in wax structure due to air pollutants probably arise from direct interactions between pollutants such as ozone and wax biosynthesis. The literature describing changes in wax composition due to pollutants is briefly reviewed. New evidence is introduced in support of the hypothesis for a direct interaction between air pollutants and epicuticular wax Biosynthesis. (orig.)

  11. Low-pressure injection molding of alumina ceramics using a carnauba wax binder: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Quevedo Nogueira, R.E.F.; Bezerra, A.C.; Santos, F.C. dos [Dept. de Engenharia Mecanica, Centro de Tecnologia-UFC, Fortaleza, CE (Brazil); Sousa, M.R. de; Acchar, W. [Dept. de Engenharia Mecanica, Univ. Federal do Rio Grande do Norte, UFRN-Campus Univ., Natal, RN (Brazil)

    2001-07-01

    Carnauba wax, a natural product from Northeastern Brazil, has found application in the processing of ceramics. However, the use of pure carnauba wax is not recommended due to its narrow melting range and poor mechanical properties. In the present work carnauba wax based organic vehicles with the addition of low-density polyethylene and stearic acid were developed for use in the low-pressure injection molding of alumina ceramics. Viscosimetric testing was employed for the determination of optimal composition of the organic vehicle. The optimal content of ceramic powder in the mixture was also determined. All the materials used are easily available in the Brazilian market. A simple ceramic part was injected at low pressures (0.6 MPa) using a semi-automatic injection molding machine. For this purpose a double cavity mold was designed and built. Preliminary results demonstrate the technical viability of the process using the organic vehicle developed. (orig.)

  12. Anti-botrytis activity in epicuticular waxes of young grape berries of Vitis vinifera (Pinot noir

    Directory of Open Access Journals (Sweden)

    Pascal Comménil

    1996-03-01

    The evidence of a substance which exhibits a strong inhibition on the conidial germination of Botrytis cinerea was made after epicuticular waxes chromatographic analysis and biological tests. This compound, characterized by a Rf (0,2 closely related to the Rf of the primary alcohols, was present in the wax extracts originated from bloom and immature grape berries stages and it was absent in the extracts issued to the mature grape berries. The concentration of the conidial germination inhibitor was markedly different between the sensible (S792 and tolerant (T7613 cultivars of Pinot vineyards. Also this antifungal product would be considereted as an hypothetical resistance marked against Botrytis cinerea.

  13. Production, property, and application of bacterial cellulose; Bakuteriaserurosu no seisan, butsusei no tokucho to sono riyo

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, S.; Watanabe, K. [Ajinomoto Co. Inc., Tokyo (Japan). Central Research Lab.; Iguchi, M. [Agency of Industrial Science and Technology, Tokyo (Japan)] Nishi, Y. [Sony Corp., Tokyo (Japan)

    1998-09-01

    Cellulose produced by bacterial is called bacterial cellulose (BC). The morphology and physical properties of BC are found to be quite unique in comparison with those of higher class plants. The properties are elucidated and a study is made to utilize the properties. The outline of this study is introduced in the sequence of BC production, BC morphology, elucidation of the physical property, and study on the application. BC consists of ultrafine fibers, and the widths of fibers are in the range from (1/199) to (1/1,000) of cotton fibers, forming distinctive network structure. It is assumed that the high Young`s modulus is based on the structural features of BC. Researches have been made on various applications to such fields as audio, paper, food, and compounds where the features of cellulose are utilized effectively. The morphology of cellulose can be varied by adding drugs which can change a part of the protein. It is expected that cellulose structure can be controlled in the future by the application of this technology. 18 refs., 6 figs., 2 tabs.

  14. Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

    Science.gov (United States)

    Asem, Dhaneshwaree; Leo, Vincent Vineeth; Passari, Ajit Kumar; Tonsing, Mary Vanlalhruaii; Joshi, J Beslin; Uthandi, Sivakumar; Hashem, Abeer; Abd Allah, Elsayed Fathi; Singh, Bhim Pratap

    2017-01-01

    The gastrointestinal (GI) habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk) and a domesticated goat (Black Bengal) were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF) of D2 (alkaline pretreated pulpy biomass) using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL) and FPase (0.5 U/mL) activities (55°C, pH 8). The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

  15. Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

    Directory of Open Access Journals (Sweden)

    Dhaneshwaree Asem

    Full Text Available The gastrointestinal (GI habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk and a domesticated goat (Black Bengal were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF of D2 (alkaline pretreated pulpy biomass using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL and FPase (0.5 U/mL activities (55°C, pH 8. The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

  16. Bacterial cellulose production from cotton-based waste textiles: enzymatic saccharification enhanced by ionic liquid pretreatment.

    Science.gov (United States)

    Hong, Feng; Guo, Xiang; Zhang, Shuo; Han, Shi-fen; Yang, Guang; Jönsson, Leif J

    2012-01-01

    Cotton-based waste textiles were explored as alternative feedstock for production of bacterial cellulose (BC) by Gluconacetobacter xylinus. The cellulosic fabrics were treated with the ionic liquid (IL) 1-allyl-3-methylimidazolium chloride ([AMIM]Cl). [AMIM]Cl caused 25% inactivation of cellulase activity at a concentration as low as of 0.02 g/mL and decreased BC production during fermentation when present in concentrations higher than 0.0005 g/mL. Therefore, removal of residual IL by washing with hot water was highly beneficial to enzymatic saccharification as well as BC production. IL-treated fabrics exhibited a 5-7-fold higher enzymatic hydrolysis rate and gave a seven times larger yield of fermentable sugars than untreated fabrics. BC from cotton cloth hydrolysate was obtained at an yield of 10.8 g/L which was 83% higher than that from the culture grown on glucose-based medium. The BC from G. xylinus grown on IL-treated fabric hydrolysate had a 79% higher tensile strength than BC from glucose-based culture medium which suggests that waste cotton pretreated with [AMIM]Cl has potential to serve as a high-quality carbon source for BC production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Increasing antibiotic resistance in preservative-tolerant bacterial strains isolated from cosmetic products.

    Science.gov (United States)

    Orús, Pilar; Gomez-Perez, Laura; Leranoz, Sonia; Berlanga, Mercedes

    2015-03-01

    To ensure the microbiological quality, consumer safety and organoleptic properties of cosmetic products, manufacturers need to comply with defined standards using several preservatives and disinfectants. A drawback regarding the use of these preservatives is the possibility of generating cross-insusceptibility to other disinfectants or preservatives, as well as cross resistance to antibiotics. Therefore, the objective of this study was to understand the adaptive mechanisms of Enterobacter gergoviae, Pseudomonas putida and Burkholderia cepacia that are involved in recurrent contamination in cosmetic products containing preservatives. Diminished susceptibility to formaldehyde-donors was detected in isolates but not to other preservatives commonly used in the cosmetics industry, although increasing resistance to different antibiotics (β-lactams, quinolones, rifampicin, and tetracycline) was demonstrated in these strains when compared with the wild-type strain. The outer membrane protein modifications and efflux mechanism activities responsible for the resistance trait were evaluated. The development of antibiotic-resistant microorganisms due to the selective pressure from preservatives included in cosmetic products could be a risk for the emergence and spread of bacterial resistance in the environment. Nevertheless, the large contribution of disinfection and preservation cannot be denied in cosmetic products. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  18. Enhanced production of bacterial cellulose by using a biofilm reactor and its material property analysis

    Directory of Open Access Journals (Sweden)

    Demirci Ali

    2009-07-01

    Full Text Available Abstract Bacterial cellulose has been used in the food industry for applications such as low-calorie desserts, salads, and fabricated foods. It has also been used in the paper manufacturing industry to enhance paper strength, the electronics industry in acoustic diaphragms for audio speakers, the pharmaceutical industry as filtration membranes, and in the medical field as wound dressing and artificial skin material. In this study, different types of plastic composite support (PCS were implemented separately within a fermentation medium in order to enhance bacterial cellulose (BC production by Acetobacter xylinum. The optimal composition of nutritious compounds in PCS was chosen based on the amount of BC produced. The selected PCS was implemented within a bioreactor to examine the effects on BC production in a batch fermentation. The produced BC was analyzed using X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, thermogravimetric analysis (TGA, and dynamic mechanical analysis (DMA. Among thirteen types of PCS, the type SFYR+ was selected as solid support for BC production by A. xylinum in a batch biofilm reactor due to its high nitrogen content, moderate nitrogen leaching rate, and sufficient biomass attached on PCS. The PCS biofilm reactor yielded BC production (7.05 g/L that was 2.5-fold greater than the control (2.82 g/L. The XRD results indicated that the PCS-grown BC exhibited higher crystallinity (93% and similar crystal size (5.2 nm to the control. FESEM results showed the attachment of A. xylinum on PCS, producing an interweaving BC product. TGA results demonstrated that PCS-grown BC had about 95% water retention ability, which was lower than BC produced within suspended-cell reactor. PCS-grown BC also exhibited higher Tmax compared to the control. Finally, DMA results showed that BC from the PCS biofilm reactor increased its mechanical property values, i.e., stress at break and Young's modulus when compared to

  19. Bacterial Infection of Fly Ovaries Reduces Egg Production and Induces Local Hemocyte Activation

    OpenAIRE

    Brandt, Stephanie M.; Schneider, David S.

    2007-01-01

    Morbidity, the state of being diseased, is an important aspect of pathogenesis that has gone relatively unstudied in fruit flies. Our interest is in characterizing how bacterial pathogenesis affects various physiologies of the fly. We chose to examine the fly ovary because we found bacterial infection had a striking effect on fly reproduction. We observed decreased egg laying after bacterial infection that correlated with increased bacterial virulence. We also found that bacteria colonized th...

  20. Wax co-cracking synergism of high density polyethylene to alternative fuels

    Directory of Open Access Journals (Sweden)

    Magdy Motawie

    2015-09-01

    Full Text Available Attempts have been made to understand the thermal degradation of high density polyethylene (HDPE and their combined co-cracking using different ratios of HDPE and petroleum wax under nitrogen atmosphere. We have conducted the experiments using HDPE as the raw material and petroleum wax as co-feed by at 400 and 450 °C reaction temperatures. The product distribution was noted along with reaction time of 0.5–3 h for the degradation. Thermal gravimetric analysis (TGA technique was used to measure the weight change of the feedstock as a function of temperature and time. Differential scanning calorimetry (DSC was used to determine the degradation temperature. Products were characterized using gas chromatography (GC and infrared spectroscopy (FTIR, some other standard physical methods were used to determine the main properties of the liquid products. Results show that the mixed plastic-wax samples could be converted into gases, gasoline, and middle distillate depending upon the composition of feed polymer/wax ratio. It was found that the products mostly consisted of paraffin and olefin compounds, with carbon numbers of C1–C4, C5–C9 and C10–C19 in the case of gases, gasoline and middle distillate respectively.

  1. Bacterial production in Guanabara Bay (Rio de Janeiro, Brazil evaluated by ³H-leucine incorporation

    Directory of Open Access Journals (Sweden)

    Alessandra M. Gonzalez

    2000-01-01

    Full Text Available The aim of this work was to evaluate the necessary ³H-leucine concentration to estimate bacterial production in Guanabara Bay through saturation curves. A second aim was to collect preliminary data of bacterial production in two distinct sites corresponding to different water qualities: Urca inlet and Governador Island. Saturation curves were made with water samples taken at the main circulation channel of the bay, Paquetá Island, and the two sites mentioned before. The ³H-leucine curves showed similar pattern for all studied areas, indicating the ideal isotope concentration to be 10 nM. Bacterial biomass production ranged from 0.40 to 4.53 µgC L-1 h-1 in Urca and from 3.86 to 73.72 µgC L-1 h-1 in Governador Island indicating the relationship between nutrients and organic matter supply and bacterial productivity. This work is an important reference for studies on trophodynamics, biogeochemical cycles and modelling in Guanabara Bay.O objetivo desse trabalho foi realizar curvas de saturação a fim de otimizar a concentração de ³H-leucina necessária para avaliar produção bacteriana na Baía de Guanabara. Objetivou-se ainda a aquisição de dados preliminares de produção bacteriana em dois locais distintos em termos de qualidade de água : enseada da Urca e Ilha do Governador. As amostras para as curvas foram obtidas na região do Canal Central e na Ilha de Paquetá, além dos dois locais de coleta citados acima. Seguiu-se a metodologia descrita por Kirchman et al. (1985 e modificada por Smith & Azam (1992. As curvas de ³H-leucina mostraram um padrão semelhante para todas as áreas estudadas, indicando a concentração ótima de isótopo de 10 nM. A produção de biomassa bacteriana variou de 0,40 a 4,53 µgC L-1 h-1 na Urca e de 3,86 a 73,72 µgC L-1 h-1 na Ilha do Governador confirmando a relação entre a disponibilidade de nutrientes e matéria orgânica e o aumento da produtividade bacteriana. Essas análises poderão ser

  2. Seaweed as source of energy. I: effect of a specific bacterial strain on biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Rao, P.S.; Tarwade, S.J.; Sarma, K.S.R.

    1980-01-01

    Biogas was produced from seaweed by making use of alginate-digesting marine bacteria that were isolated from decomposing seaweed and can digest seaweed carbohydrates (agar and alginic acid). Laboratory digesters containing 100 g seaweed were inoculated with 50 mL broth cultures of different seaweed-derived bacterial strains, and the maximum amount of degradation obtained was 28% (compared with 13% for a bacteria-free digestion). Cow dung was added as a source of methanogenic bacteria, and the amount of biogas produced was more than double the amount obtained when seaweed and cow dung were digested in the absence of the seaweed-derived bacteria. Adding a small amount of Ulva to the seaweed digester increased the production of biogas.

  3. Sintering of wax for controlling release from pellets.

    Science.gov (United States)

    Singh, Reena; Poddar, S S; Chivate, Amit

    2007-09-14

    The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%-20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusion of ground or emulsified carnauba wax did not sustain the release of theophylline for more than 3 hours. Matrix pellets of theophylline prepared with various concentrations of carnauba wax were sintered thermally at various times and temperatures. In vitro drug release profiles indicated an increase in drug release retardation with increasing carnauba wax concentration. Pellets prepared with ground wax showed a higher standard deviation than did those prepared with emulsified wax. There was incomplete release at the end of 12 hours for pellets prepared with 20% ground or emulsified wax. The sintering temperature and duration were optimized to allow for a sustained release lasting at least 12 hours. The optimized temperature and duration were found to be 100 degrees C and 140 seconds, respectively. The sintered pellets had a higher hydrophobicity than did the unsintered pellets. Scanning electron micrographs indicated that the carnauba wax moved internally, thereby increasing the surface area of wax within the pellets.

  4. Agricultural and Management Practices and Bacterial Contamination in Greenhouse versus Open Field Lettuce Production

    Science.gov (United States)

    Holvoet, Kevin; Sampers, Imca; Seynnaeve, Marleen; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2014-01-01

    The aim of this study was to gain insight into potential differences in risk factors for microbial contamination in greenhouse versus open field lettuce production. Information was collected on sources, testing, and monitoring and if applicable, treatment of irrigation and harvest rinsing water. These data were combined with results of analysis on the levels of Escherichia coli as a fecal indicator organism and the presence of enteric bacterial pathogens on both lettuce crops and environmental samples. Enterohemorragic Escherichia coli (EHEC) PCR signals (vt1 or vt2 positive and eae positive), Campylobacter spp., and Salmonella spp. isolates were more often obtained from irrigation water sampled from open field farms (21/45, 46.7%) versus from greenhouse production (9/75, 12.0%). The open field production was shown to be more prone to fecal contamination as the number of lettuce samples and irrigation water with elevated E. coli was significantly higher. Farmers comply with generic guidelines on good agricultural practices available at the national level, but monitoring of microbial quality, and if applicable appropriateness of water treatment, or water used for irrigation or at harvest is restricted. These results indicate the need for further elaboration of specific guidelines and control measures for leafy greens with regard to microbial hazards. PMID:25546272

  5. Novel keratin modified bacterial cellulose nanocomposite production and characterization for skin tissue engineering.

    Science.gov (United States)

    Keskin, Zalike; Sendemir Urkmez, Aylin; Hames, E Esin

    2017-06-01

    As it is known that bacterial cellulose (BC) is a biocompatible and natural biopolymer due to which it has a large set of biomedical applications. But still it lacks some desired properties, which limits its uses in many other applications. Therefore, the properties of BC need to be boosted up to an acceptable level. Here in this study for the first time, a new natural nanocomposite was produced by the incorporating keratin (isolated from human hair) to the BC (produced by Acetobacter xylinum) to enhance dermal fibroblast cells' attachment. Two different approaches were used in BC based nanocomposite production: in situ and post modifications. BC/keratin nanocomposites were characterized using SEM, FTIR, EDX, XRD, DSC and XPS analyses. Both production methods have yielded successful results for production of BC based nanocomposite-containing keratin. In vitro cell culture experiments performed with human skin keratinocytes and human skin fibroblast cells indicate the potential of the novel BC/keratin nanocomposites for use in skin tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Production of bacterial cellulose using different carbon sources and culture media.

    Science.gov (United States)

    Mohammadkazemi, Faranak; Azin, Mehrdad; Ashori, Alireza

    2015-03-06

    In this work, the effects of carbon sources and culture media on the production and structural properties of bacterial cellulose (BC) have been studied. BC nanofibers were synthesized using Gluconacetobacter xylinus strain PTCC 1734. Media used were Hestrin-Schramm (H), Yamanaka (Y), and Zhou (Z). Five different carbon sources, namely date syrup, glucose, mannitol, sucrose, and food-grade sucrose were used in these media. All the produced BC pellicles were characterized in terms of dry weight production, biomass yield, thermal stability, crystallinity and morphology by thermogravimetric analysis (TGA), x-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). The obtained results showed that mannitol lead to the highest yield, followed by sucrose. The highest production efficiency of mannitol might be due to the nitrogen source, which plays an important role. The maximum improvement on the thermal stability of the composites was achieved when mannitol was used in H medium. In addition, the crystallinity was higher in BC formed in H medium compared to other media. FE-SEM micrographs illustrated that the BC pellicles, synthesized in the culture media H and Z, were stable, unlike those in medium Y that were unstable. The micrographs of BC produced in media containing mannitol and sucrose provided evidence of the strong interfacial adhesion between the BC fibers without noticeable aggregates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Phytoplankton production systems in a shellfish hatchery: variations of the bacterial load and diversity of vibrios.

    Science.gov (United States)

    Dubert, J; Fernández-Pardo, A; Nóvoa, S; Barja, J L; Prado, S

    2015-06-01

    Outbreaks of disease caused by some Vibrio species represent the main production bottleneck in shellfish hatcheries. Although the phytoplankton used as food is one of the main sources of bacteria, studies of the associated bacterial populations, specifically vibrios, are scarce. The aim of the study was the microbiological monitoring of the microalgae as the first step in assessing the risk disease for bivalve cultures. Two phytoplankton production systems were sampled weekly throughout 1-year period in a bivalve hatchery. Quantitative analysis revealed high levels of marine heterotrophic bacteria in both systems throughout the study. Presumptive vibrios were detected occasionally and at low concentrations. In most of the cases, they belonged to the Splendidus and Harveyi clades. The early detection of vibrios in the microalgae may be the key for a successful bivalve culture. Their abundance and diversity were affected by factors related to the hatchery environment. This work represents the first long study where the presence of vibrios was evaluated rigorously in phytoplankton production systems and provides a suitable microbiological protocol to control and guarantee the quality of the algal cultures to avoid the risk of transferring potential pathogens to shellfish larvae and/or broodstock. © 2015 The Society for Applied Microbiology.

  8. Bacterial Growth Phase Influences Methylmercury Production by the Sulfate-Reducing Bacterium Desulfovibrio desulfuricans ND132

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Abir [ORNL; Brooks, Scott C [ORNL; Miller, Carrie L [ORNL; Mosher, Jennifer J [ORNL; Yin, Xiangping Lisa [ORNL; Drake, Meghan M [ORNL

    2011-01-01

    The effect of bacterial growth phase is an aspect of mercury (Hg) methylation that previous studies have not investigated in detail. Here we consider the effect of growth phase (mid-log, late-log and late stationary phase) on Hg methylation by the known methylator Desulfovibrio desulfuricans ND132. We tested the addition of Hg alone (chloride-complex), Hg with Suwannee River natural organic matter (SRNOM) (unequilibrated), and Hg equilibrated with SRNOM on monomethylmercury (MMHg) production by ND132 over a growth curve in pyruvate-fumarate media. This NOM did not affect MMHg production even under very low Hg:SRNOM ratios, where Hg binding is predicted to be dominated by high energy sites. Adding Hg or Hg-NOM to growing cultures 24h before sampling (late addition) resulted in {approx}2x greater net fraction of Hg methylated than for comparably aged cultures exposed to Hg from the initial culture inoculation (early addition). Mid- and late-log phase cultures produced similar amounts of MMHg, but late stationary phase cultures (both under early and late Hg addition conditions) produced up to {approx}3x more MMHg, indicating the potential importance of growth phase in studies of MMHg production.

  9. Bacterial Growth Phase Influences Methylmercury Production by the Sulfate-Reducing Bacterium Desulfovibrio desulfuricans ND132

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Abir [ORNL; Brooks, Scott C [ORNL; Miller, Carrie L [ORNL; Mosher, Jennifer J [ORNL; Yin, Xiangping Lisa [ORNL; Drake, Meghan M [ORNL

    2011-01-01

    The effect of bacterial growth phase is an aspect of mercury (Hg) methylation that previous studies have not investigated in detail. Here we consider the effect of growth phase (mid-log, late-log and late stationary phase) on Hg methylation by the known methylator Desulfovibrio desulfuricans ND132. We tested the addition of Hg alone (chloride-complex), Hg with Suwannee River natural organic matter (SRNOM) (unequilibrated), and Hg equilibrated with SRNOM on monomethylmercury (MMHg) production by ND132 over a growth curve in pyruvate fumarate media. This NOM did not affect MMHg production even under very low Hg: SRNOM ratios, where Hg binding is predicted to be dominated by high energy sites. Adding Hg or Hg NOM to growing cultures 24 h before sampling (late addition) resulted in ~2 greater net fraction of Hg methylated than for comparably aged cultures exposed to Hg from the initial culture inoculation (early addition). Mid-and late-log phase cultures produced similar amounts of MMHg, but late stationary phase cultures (both under early and late Hg addition conditions) produced up to ~3 more MMHg, indicating the potential importance of growth phase in studies of MMHg production.

  10. Use of the [(14)C]leucine incorporation technique to measure bacterial production in river sediments and the epiphyton.

    Science.gov (United States)

    Fischer, H; Pusch, M

    1999-10-01

    Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [(14)C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sediments, the biofilms on aquatic plants (epiphyton), and the pelagic zone, (iii) bacterial activities at different leucine concentrations, (iv) specificity of leucine uptake by bacteria, and (v) the effect of the incubation technique (perfused-core incubation versus slurry incubation) on leucine incorporation into protein. Bacterial protein was best extracted from sediments and precipitated by hot trichloroacetic acid treatment following ultrasonication. For epiphyton, an alkaline-extraction procedure was most efficient. Leucine incorporation saturation occurred at 1 microM in epiphyton and 100 nM in the pelagic zone. Saturation curves in sediments were difficult to model but showed the first level of leucine saturation at 50 microM. Increased uptake at higher leucine concentrations could be partly attributed to eukaryotes. Addition of micromolar concentrations of leucine did not enhance bacterial electron transport activity or DNA replication activity. Similar rates of leucine incorporation into protein calculated for whole sediment cores were observed after slurry and perfused-core incubations, but the rates exhibited strong vertical gradients after the core incubation. We conclude that the leucine incorporation method can measure bacterial production in a wide range of aquatic habitats, including fluvial sediments, if substrate saturation and isotope dilution are determined.

  11. Use of the [14C]Leucine Incorporation Technique To Measure Bacterial Production in River Sediments and the Epiphyton

    Science.gov (United States)

    Fischer, Helmut; Pusch, Martin

    1999-01-01

    Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [14C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sediments, the biofilms on aquatic plants (epiphyton), and the pelagic zone, (iii) bacterial activities at different leucine concentrations, (iv) specificity of leucine uptake by bacteria, and (v) the effect of the incubation technique (perfused-core incubation versus slurry incubation) on leucine incorporation into protein. Bacterial protein was best extracted from sediments and precipitated by hot trichloroacetic acid treatment following ultrasonication. For epiphyton, an alkaline-extraction procedure was most efficient. Leucine incorporation saturation occurred at 1 μM in epiphyton and 100 nM in the pelagic zone. Saturation curves in sediments were difficult to model but showed the first level of leucine saturation at 50 μM. Increased uptake at higher leucine concentrations could be partly attributed to eukaryotes. Addition of micromolar concentrations of leucine did not enhance bacterial electron transport activity or DNA replication activity. Similar rates of leucine incorporation into protein calculated for whole sediment cores were observed after slurry and perfused-core incubations, but the rates exhibited strong vertical gradients after the core incubation. We conclude that the leucine incorporation method can measure bacterial production in a wide range of aquatic habitats, including fluvial sediments, if substrate saturation and isotope dilution are determined. PMID:10508068

  12. A consistent and predictable commercial broiler chicken bacterial microbiota in antibiotic-free production displays strong correlations with performance.

    Science.gov (United States)

    Johnson, Timothy J; Youmans, Bonnie P; Noll, Sally; Cardona, Carol; Evans, Nicholas P; Karnezos, T Peter; Ngunjiri, John M; Abundo, Michael C; Lee, Chang-Won

    2018-04-06

    Defining the baseline bacterial microbiome is critical towards understanding its relationship with health and disease. In broiler chickens, the core microbiome and its possible relationships with health and disease have been difficult to define due to high variability between birds and flocks. Presented are data from a large, comprehensive microbiota-based study in commercial broilers. The primary goals of this study included understanding what constitutes the core bacterial microbiota in the broiler gastrointestinal, respiratory, and barn environments; how these core players change across age, geography, and time; and which bacterial taxa correlate with enhanced bird performance in antibiotic-free flocks. Using 2,309 samples from 37 different commercial flocks within a vertically integrated broiler system, and metadata from these and an additional 512 flocks within that system, the baseline bacterial microbiota was defined using 16S rRNA gene sequencing. The effects of age, sample type, flock, and successive flock cycles were compared, and results indicate a consistent, predictable, age-dependent bacterial microbiota, irrespective of flock. The tracheal bacterial microbiota of broilers was comprehensively defined, and Lactobacillus was the dominant bacterial taxa in the trachea. Numerous bacterial taxa were identified which were strongly correlated with broiler chicken performance, across multiple tissues. While many positively correlated taxa were identified, negatively associated potential pathogens were also identified in the absence of clinical disease, indicating subclinical dynamics occurring that impact performance. Overall, this work provides necessary baseline data for the development of effective antibiotic alternatives, such as probiotics, for sustainable poultry production. Importance Multidrug resistant bacterial pathogens are perhaps the greatest medical challenge we will face in the 21 st century and beyond. Antibiotics are necessary in animal

  13. Evolutionary Conserved Function of Barley and Arabidopsis 3-KETOACYL-CoA SYNTHASES in Providing Wax Signals for Germination of Powdery Mildew Fungi1[C][W

    Science.gov (United States)

    Weidenbach, Denise; Jansen, Marcus; Franke, Rochus B.; Hensel, Goetz; Weissgerber, Wiebke; Ulferts, Sylvia; Jansen, Irina; Schreiber, Lukas; Korzun, Viktor; Pontzen, Rolf; Kumlehn, Jochen; Pillen, Klaus; Schaffrath, Ulrich

    2014-01-01

    For plant pathogenic fungi, such as powdery mildews, that survive only on a limited number of host plant species, it is a matter of vital importance that their spores sense that they landed on the right spot to initiate germination as quickly as possible. We investigated a barley (Hordeum vulgare) mutant with reduced epicuticular leaf waxes on which spores of adapted and nonadapted powdery mildew fungi showed reduced germination. The barley gene responsible for the mutant wax phenotype was cloned in a forward genetic screen and identified to encode a 3-KETOACYL-CoA SYNTHASE (HvKCS6), a protein participating in fatty acid elongation and required for synthesis of epicuticular waxes. Gas chromatography-mass spectrometry analysis revealed that the mutant has significantly fewer aliphatic wax constituents with a chain length above C-24. Complementation of the mutant restored wild-type wax and overcame germination penalty, indicating that wax constituents less present on the mutant are a crucial clue for spore germination. Investigation of Arabidopsis (Arabidopsis thaliana) transgenic plants with sense silencing of Arabidopsis REQUIRED FOR CUTICULAR WAX PRODUCTION1, the HvKCS6 ortholog, revealed the same germination phenotype against adapted and nonadapted powdery mildew fungi. Our findings hint to an evolutionary conserved mechanism for sensing of plant surfaces among distantly related powdery mildews that is based on KCS6-derived wax components. Perception of such a signal must have been evolved before the monocot-dicot split took place approximately 150 million years ago. PMID:25201879

  14. Leaky RAG Deficiency in Adult Patients with Impaired Antibody Production against Bacterial Polysaccharide Antigens.

    Directory of Open Access Journals (Sweden)

    Christoph B Geier

    Full Text Available Loss of function mutations in the recombination activating genes RAG1 and RAG2 have been reported to cause a T-B-NK+ type of severe combined immunodeficiency. In addition identification of hypomorphic mutations in RAG1 and RAG2 has led to an expansion of the spectrum of disease to include Omenn syndrome, early onset autoimmunity, granuloma, chronic cytomegalovirus- or EBV-infection with expansion of gamma/delta T-cells, idiophatic CD4 lymphopenia and a phenotype resembling common variable immunodeficiency. Herein we describe a novel presentation of leaky RAG1 and RAG2 deficiency in two unrelated adult patients with impaired antibody production against bacterial polysaccharide antigens. Clinical manifestation included recurrent pneumonia, sinusitis, otitis media and in one patient recurrent cutaneous vasculitis. Both patients harbored a combination of a null mutation on one allele with a novel hypomorphic RAG1/2 mutation on the other allele. One of these novel mutations affected the start codon of RAG1 and resulted in an aberrant gene and protein expression. The second novel RAG2 mutation leads to a truncated RAG2 protein, lacking the C-terminus with intact core RAG2 and reduced VDJ recombination capacity as previously described in a mouse model. Both patients presented with severely decreased numbers of naïve CD4+ T cells and defective T independent IgG responses to bacterial polysaccharide antigens, while T cell-dependent IgG antibody formation e.g. after tetanus or TBEV vaccination was intact. In conclusion, hypomorphic mutations in genes responsible for SCID should be considered in adults with predominantly antibody deficiency.

  15. Dental wax decreases calculus accumulation in small dogs.

    Science.gov (United States)

    Smith, Mark M; Smithson, Christopher W

    2014-01-01

    A dental wax was evaluated after unilateral application in 20 client-owned, mixed and purebred small dogs using a clean, split-mouth study model. All dogs had clinical signs of periodontal disease including plaque, calculus, and/or gingivitis. The wax was randomly applied to the teeth of one side of the mouth daily for 30-days while the contralateral side received no treatment. Owner parameters evaluated included compliance and a subjective assessment of ease of wax application. Gingivitis, plaque and calculus accumulation were scored at the end of the study period. Owners considered the wax easy to apply in all dogs. Compliance with no missed application days was achieved in 8 dogs. The number of missed application days had no effect on wax efficacy. There was no significant difference in gingivitis or plaque accumulation scores when comparing treated and untreated sides. Calculus accumulation scores were significantly less (22.1 %) for teeth receiving the dental wax.

  16. Natural oils and waxes: studies on stick bases.

    Science.gov (United States)

    Budai, Lívia; Antal, István; Klebovich, Imre; Budai, Marianna

    2012-01-01

    The objective of the present article was to examine the role of origin and quantity of selected natural oils and waxes in the determination of the thermal properties and hardness of stick bases. The natural oils and waxes selected for the study were sunflower, castor, jojoba, and coconut oils. The selected waxes were yellow beeswax, candelilla wax, and carnauba wax. The hardness of the formulations is a critical parameter from the aspect of their application. Hardness was characterized by the measurement of compression strength along with the softening point, the drop point, and differential scanning calorimetry (DSC). It can be concluded that coconut oil, jojoba oil, and carnauba wax have the greatest influence on the thermal parameters of stick bases.

  17. Flow and linear coefficient of thermal expansion of four types of Base Plate waxes compared with ADA standard

    Directory of Open Access Journals (Sweden)

    Monzavi A

    2002-07-01

    Full Text Available Waxes have a lot of applications in dentistry. Such materials are of thermoplastic type that undergoes deformation in different temperatures. Two important properties of base plate waxes are flow and their coefficient of linear thermal expansion. Recently, different institutions, inside the country, produce dentistry waxes, while they have not been standardized. Consequently, consumers' dissatisfaction are observed. In this research, the two above- mentioned factors were compared between three kinds of Iranian waxes with Cavex that is foreign production, based on test number 24 of ADA. To measure the flow rate in the temperatures of 23, 37 and 45°c, Wilcoxon statistical analysis was used. The results showed that in 23°c, the flow rate of Cavex and Azardent waxes met ADA standards; however, it was not true for two others types. In 37°c, the flow of none of the waxes was standardized and in 45°c their flow was acceptable, moreover, thermal expansion coefficient, for Cavex and Azardent types, was based on ADA standard.

  18. A new experimental method to prevent paraffin - wax formation on the crude oil wells: A field case study in Libya

    Directory of Open Access Journals (Sweden)

    Elhaddad Elnori E.

    2015-01-01

    Full Text Available Wax formation and deposition is one of the most common problems in oil producing wells. This problem occurs as a result of the reduction of the produced fluid temperature below the wax appearance temperature (range between 46°C and 50°C and the pour point temperature (range between 42°C and 44°C. In this study, two new methods for preventing wax formation were implemented on three oil wells in Libya, where the surface temperature is, normally, 29°C. In the first method, the gas was injected at a pressure of 83.3 bar and a temperature of 65°C (greater than the pour point temperature during the gas-lift operation. In the second method, wax inhibitors (Trichloroethylene-xylene (TEX, Ethylene copolymers, and Comb polymers were injected down the casings together with the gas. Field observations confirmed that by applying these techniques, the production string was kept clean and no wax was formed. The obtained results show that the wax formation could be prevented by both methods.

  19. Evaluation of methods for wax determination in crude oil; Avaliacao de metodos de determinacao de parafinas em petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Julio Cesar M.; Silva, Maria do Socorro A.J. da; Vasconcellos, Rosa C.U. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Tamanqueira, Juliana B. [Fundacao Gorceix, Ouro Preto, MG (Brazil)

    2008-07-01

    Determining the wax content of crude oil is of great importance for petroleum industry, especially for production, storage and transportation of crude oils. Many different methodologies of wax determining are available in the technical literature. However, the selection of the most suitable method must be in accordance with the aim of the analysis and observing the specificities of each technique. The purpose of this work was to determine the performance of different techniques of wax determining applied to characterization of precipitation properties of waxy compounds in crude oils. Twelve samples of crude oils proceeding from the main Brazilian oil producing sedimentary basins were selected for this study. These samples were analyzed by three important analytical techniques of wax determining: precipitation by cooled solvent; liquid chromatography with precipitation by cooled solvent; and liquid chromatography followed by gas chromatography. Differential scanning calorimetry data related to the wax crystallization in these oils were used as parameters of validation. The results obtained in this study indicate that the liquid chromatography followed by gas chromatography method has the best performance for wax determining in crude oils. (author)

  20. Biocontrol of Fusarium graminearum Growth and Deoxynivalenol Production in Wheat Kernels with Bacterial Antagonists

    Directory of Open Access Journals (Sweden)

    Cuijuan Shi

    2014-01-01

    Full Text Available Fusarium graminearum is the main causal pathogen affecting small-grain cereals, and it produces deoxynivalenol, a kind of mycotoxin, which displays a wide range of toxic effects in human and animals. Bacterial strains isolated from peanut shells were investigated for their activities against F. graminearum by dual-culture plate and tip-culture assays. Among them, twenty strains exhibited potent inhibition to the growth of F. graminearum, and the inhibition rates ranged from 41.41% to 54.55% in dual-culture plate assay and 92.70% to 100% in tip-culture assay. Furthermore, eighteen strains reduced the production of deoxynivalenol by 16.69% to 90.30% in the wheat kernels assay. Finally, the strains with the strongest inhibitory activity were identified by morphological, physiological, biochemical methods and also 16S rDNA and gyrA gene analysis as Bacillus amyloliquefaciens. The current study highlights the potential application of antagonistic microorganisms and their metabolites in the prevention of fungal growth and mycotoxin production in wheat kernels. As a biological strategy, it might avoid safety problems and nutrition loss which always caused by physical and chemical strategies.

  1. Catalytic cracking of slack wax with molten mixtures containing aluminum chloride and bromide. [Wax obtained in the process of dewaxing lubricating oils

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuka, Y; Oizumi, K; Tamai, Y

    1983-09-01

    The catalytic cracking of slack wax with molten mixtures of AlCl/sub 3/ (aluminum chloride) and AlBr/sub 3/ (aluminum bromide) was investigated in an atmospheric semi-batch reactor at low temperatures of 100 to 160/sup 0/C. The cracking rate was proportional to the amount of unreacted wax. The conversion at 135/sup 0/C reached 25 wt % under typical reaction conditions. About 95 wt % of the cracking products consisted of isobutane, 2-methylbutane, and methylpentanes, ca. 50% of these isoparaffins being isobutane. The difference in cracking activity between this catalyst and a solid acid catalyst is discussed based on the product distribution. Hardly any reaction took place without HCl, which shows that the presence of HCl is essential for this cracking. The cracking rate increased sharply with an increase in the amount of the catalyst. The rate did not depend on the composition of the AlCl/sub 3//sup -/ AlBr/sub 3/ catalyst, but the product distribution did depend on it and the content of the gasoline fraction in the products increased with an increase in the concentration of AlBr/sub 3/. The cracking residue was characterized by IR and NMR spectroscopy. The results show that the cracking reaction probably occurs heterogeneously at the interface between the liquid wax and the molten catalyst. 3 figures, 4 tables.

  2. In vivo evaluation of insect wax for hair growth potential

    Science.gov (United States)

    Ma, Jinju

    2018-01-01

    Insect wax is secreted by Ericerus pela Chavanness. It has been traditionally used to treat hair loss in China, but few reports have been published on the hair growth-promoting effect of insect wax. In this work, we examined the hair growth-promoting effects of insect wax on model animals. Different concentrations of insect wax were topically applied to the denuded backs of mice, and 5% minoxidil was applied topically as a positive control. We found that insect wax significantly promoted hair growth in a dose-dependent manner, 45% and 30% insect wax both induced hair to regrow, while less visible hair growth was observed in blank controls on the 16th day. The experimental areas treated with 45% and 30% insect wax exhibited significant differences in hair scores compared to blank controls, and hair lengths in the 45% and 30% insect wax group was significantly longer than in blank controls on the 16th and 20th days. There were no new hair follicles forming in the treated areas, and the hair follicles were prematurely converted to the anagen phase from the telogen phase in experimental areas treated with 45% and 30% insect wax. Both 45% and 30% insect wax upregulated vascular endothelial growth factor expression. The results indicated that 45% and 30% insect wax showed hair growth-promoting potential approximately as potent as 5% minoxidil by inducing the premature conversion of telogen-to-anagen and by prolonging the mature anagen phase rather than increasing the number of hair follicles, which was likely related to the upregulation of VEGF expression. The dissociative policosanol in insect wax was considered the key ingredient most likely responsible for the hair growth promoting potential. PMID:29438422

  3. Surfactants and Desensitizing Wax Substitutes for TNT-Based Systems.

    Science.gov (United States)

    1994-10-01

    greatly with the source of crude oil. Some crudes contain little wax. The U.S. crudes from Pennsylvania and the midcontinent areas contain high...years ago in Egypt for many different purposes. The term wax comes to us from the Anglo-Saxon "weax," the name given to material from the bee ...usually produced in the wild and not by large scale cultivation. Although plants produce small amounts of waxes in their tissues, seeds and pollen

  4. In vivo evaluation of insect wax for hair growth potential.

    Directory of Open Access Journals (Sweden)

    Jinju Ma

    Full Text Available Insect wax is secreted by Ericerus pela Chavanness. It has been traditionally used to treat hair loss in China, but few reports have been published on the hair growth-promoting effect of insect wax. In this work, we examined the hair growth-promoting effects of insect wax on model animals. Different concentrations of insect wax were topically applied to the denuded backs of mice, and 5% minoxidil was applied topically as a positive control. We found that insect wax significantly promoted hair growth in a dose-dependent manner, 45% and 30% insect wax both induced hair to regrow, while less visible hair growth was observed in blank controls on the 16th day. The experimental areas treated with 45% and 30% insect wax exhibited significant differences in hair scores compared to blank controls, and hair lengths in the 45% and 30% insect wax group was significantly longer than in blank controls on the 16th and 20th days. There were no new hair follicles forming in the treated areas, and the hair follicles were prematurely converted to the anagen phase from the telogen phase in experimental areas treated with 45% and 30% insect wax. Both 45% and 30% insect wax upregulated vascular endothelial growth factor expression. The results indicated that 45% and 30% insect wax showed hair growth-promoting potential approximately as potent as 5% minoxidil by inducing the premature conversion of telogen-to-anagen and by prolonging the mature anagen phase rather than increasing the number of hair follicles, which was likely related to the upregulation of VEGF expression. The dissociative policosanol in insect wax was considered the key ingredient most likely responsible for the hair growth promoting potential.

  5. Metagenetic analysis of the bacterial communities of edible insects from diverse production cycles at industrial rearing companies.

    Science.gov (United States)

    Vandeweyer, D; Crauwels, S; Lievens, B; Van Campenhout, L

    2017-11-16

    Despite the continuing development of new insect-derived food products, microbial research on edible insects and insect-based foods is still very limited. The goal of this study was to increase the knowledge on the microbial quality of edible insects by comparing the bacterial community composition of mealworms (Tenebrio molitor) and crickets (Acheta domesticus and Gryllodes sigillatus) from several production cycles and rearing companies. Remarkable differences in the bacterial community composition were found between different mealworm rearing companies and mealworm production cycles from the same company. In comparison with mealworms, the bacterial community composition of the investigated crickets was more similar among different companies, and was highly similar between both cricket species investigated. Mealworm communities were dominated by Spiroplasma and Erwinia species, while crickets were abundantly colonised by (Para)bacteroides species. With respect to food safety, only a few operational taxonomic units could be associated with potential human pathogens such as Cronobacter or spoilage bacteria such as Pseudomonas. In summary, our results implicate that at least for cricket rearing, production cycles of constant and good quality in terms of bacterial composition can be obtained by different rearing companies. For mealworms however, more variation in terms of microbial quality occurs between companies. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Effect of solvent extraction on Tunisian esparto wax composition

    Directory of Open Access Journals (Sweden)

    Saâd Inès

    2016-08-01

    Full Text Available The increase of needs for renewable and vegetable based materials will help to drive the market growth of vegetable waxes. Because of their highly variable composition and physicochemical properties, plant waxes have found numerous applications in the: food, cosmetic, candle, coating, polish etc... The aim of this project is to determine the effect of solvent extraction (petroleum ether and ethanol on Tunisian esparto wax composition. The GC-MS was applied in order to determine the waxes compositions. Then, physicochemical parameters of these two samples of waxes: acid value, saponification value, iodine value and melting point were measured in order to deduct their properties and possible fields of uses. Results showed that esparto wax composition depended on the solvent extraction and that major components of the two samples of waxes were: alkanes, esters of fatty acids and phenols. Furthermore, esparto waxes were characterized by an antioxidant and antibacterial activities but the potential of these activities depended on the solvent of wax extraction.

  7. Absorption and distribution of orally administered jojoba wax in mice.

    Science.gov (United States)

    Yaron, A; Samoiloff, V; Benzioni, A

    1982-03-01

    The liquid wax obtained from the seeds of the arid-land shrub jojoba (Simmondsia chinensis) is finding increasing use in skin treatment preparations. The fate of this wax upon reaching the digestive tract was studied. 14C-Labeled wax was administered intragastrically to mice, and the distribution of the label in the body was determined as a function of time. Most of the wax was excreted, but a small amount was absorbed, as was indicated by the distribution of label in the internal organs and the epididymal fat. The label was incorporated into the body lipids and was found to diminish with time.

  8. Modeling of asphaltene and wax precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, F.; Sarathi, P.; Jones, R.

    1991-01-01

    This research project was designed to focus on the development of a predictive technique for organic deposition during gas injection for petroleum EOR. A thermodynamic model has been developed to describe the effects of temperature, pressure, and composition on asphaltene precipitation. The proposed model combines regular solution theory with Flory-Huggins polymer solutions theory to predict maximum volume fractions of asphaltene dissolved in oil. The model requires evaluation of vapor-liquid equilibria, first using an equation of state followed by calculations of asphaltene solubility in the liquid-phase. A state-of-the-art technique for C{sub 7+} fraction characterization was employed in developing this model. The preliminary model developed in this work was able to predict qualitatively the trends of the effects of temperature, pressure, and composition. Since the mechanism of paraffinic wax deposition is different from that of asphaltene deposition, another thermodynamic model based on the solid-liquid solution theory was developed to predict the wax formation. This model is simple and can predict the wax appearance temperature with reasonable accuracy. Accompanying the modeling work, experimental studies were conducted to investigate the solubility of asphaltene in oil land solvents and to examine the effects of oil composition, CO{sub 2}, and solvent on asphaltene precipitation and its properties. This research focused on the solubility reversibility of asphaltene in oil and the precipitation caused by CO{sub 2} injection at simulated reservoir temperature and pressure conditions. These experiments have provided many observations about the properties of asphaltenes for further improvement of the model, but more detailed information about the properties of asphaltenes in solution is needed for the development of more reliable asphaltene characterization techniques. 50 refs., 8 figs., 7 tabs.

  9. Variation analysis of bacterial polyhydroxyalkanoates production using saturated and unsaturated hydrocarbons

    Directory of Open Access Journals (Sweden)

    Saiqa Tufail

    Full Text Available ABSTRACT Polyhydroxyalkanoates (PHA are efficient, renewable and environment friendly polymeric esters. These polymers are synthesized by a variety of microbes under stress conditions. This study was carried out to check the suitability of waste frying oil in comparison to other oils for economical bioplastic production. Six bacterial strains were isolated and identified as Bacillus cereus (KF270349, Klebsiella pneumoniae (KF270350, Bacillus subtilis (KF270351, Brevibacterium halotolerance (KF270352, Pseudomonas aeruginosa (KF270353, and Stenotrophomonas rhizoposid (KF270354 by ribotyping. All strains were PHA producers so were selected for PHA synthesis using four different carbon sources, i.e., waste frying oil, canola oil, diesel and glucose. Extraction of PHA was carried out using sodium hypochlorite method and maximum amount was detected after 72 h in all cases. P. aeruginosa led to maximum PHA production after 72 h at 37 °C and 100 rpm using waste frying oil that was 53.2% PHA in comparison with glucose 37.8% and cooking oil 34.4%. B. cereus produced 40% PHA using glucose as carbon source which was high when compared against other strains. A significantly lesser amount of PHA was recorded with diesel as a carbon source for all strains. Sharp Infrared peaks around 1740-1750 cm-1 were present in Fourier Transform Infrared spectra that correspond to exact position for PHA. The use of waste oils and production of poly-3hydroxybutyrate-co-3hydroxyvalerate (3HB-co-3HV by strains used in this study is a good aspect to consider for future prospects as this type of polymer has better properties as compared to PHBs.

  10. Study of phase transition in hard microcrystalline waxes and wax blends by differential scanning calorimetry

    Czech Academy of Sciences Publication Activity Database

    Kumar, S.; Agrawal, K. M.; Khan, H. U.; Sikora, Antonín

    2004-01-01

    Roč. 22, 3 & 4 (2004), s. 337-345 ISSN 1091-6466 R&D Projects: GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : phase transition * hard microscrystalline waxes * differential scanning calorimetry Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.312, year: 2004

  11. Presence of carotinoids in peat wax

    Energy Technology Data Exchange (ETDEWEB)

    Yurkevich, E.A.; Dolidovich, E.F.; Bel' kevich, P.I.; Sheremet, L.S.; Drozdovskaya, S.V.

    1986-05-01

    Discusses biologically active substances present in peat which have various pharmacological properties. Describes separation of fractions rich in carotinoids from extracts of wax tar obtained by benzine treatment of highly decomposed pine-cotton grass peat. Extraction was carried out using hot ethanol. States that although identification of individual carotinoid in the fractions separated is very difficult due to complicity of composition, the tests carried out made it possible to infer that fractions studied contain not only xanthophylls but also fucoxanthains (formed in small amounts in nature) with fairly stable structure. Ultraviolet and infrared spectra of the carotinoid containing fraction in ethanol extracts are given. 6 refs.

  12. Production of macroaggregates from dissolved exopolymeric substances (EPS) of bacterial and diatom origin

    Digital Repository Service at National Institute of Oceanography (India)

    Bhaskar, P.V.; Grossart, H.P.; Bhosle, N.B.; Simon, M.

    .J. (1985) Bacterial cell walls and surfaces. In Bacterial Adhesion. (Savage D.C. and Fletcher M, Eds) Plenum press, New York, pp: 45-70. 53. Coombs, J. and Volcani, B. E. (1968) Studies on the biochemistry and fine structure of silica-shell formation...

  13. Extracellular Lipase and Protease Production from a Model Drinking Water Bacterial Community Is Functionally Robust to Absence of Individual Members.

    Directory of Open Access Journals (Sweden)

    Graham G Willsey

    Full Text Available Bacteria secrete enzymes into the extracellular space to hydrolyze macromolecules into constituents that can be imported for microbial nutrition. In bacterial communities, these enzymes and their resultant products can be modeled as community property. Our goal was to investigate the impact of individual community member absence on the resulting community production of exoenzymes (extracellular enzymes involved in lipid and protein hydrolysis. Our model community contained nine bacteria isolated from the potable water system of the International Space Station. Bacteria were grown in static conditions individually, all together, or in all combinations of eight species and exoproduct production was measured by colorimetric or fluorometric reagents to assess short chain and long chain lipases, choline-specific phospholipases C, and proteases. The exoenzyme production of each species grown alone varied widely, however, the enzyme activity levels of the mixed communities were functionally robust to absence of any single species, with the exception of phospholipase C production in one community. For phospholipase C, absence of Chryseobacterium gleum led to increased choline-specific phospholipase C production, correlated with increased growth of Burkholderia cepacia and Sphingomonas sanguinis. Because each individual species produced different enzyme activity levels in isolation, we calculated an expected activity value for each bacterial mixture using input levels or known final composition. This analysis suggested that robustness of each exoenzyme activity is not solely mediated by community composition, but possibly influenced by bacterial communication, which is known to regulate such pathways in many bacteria. We conclude that in this simplified model of a drinking water bacterial community, community structure imposes constraints on production and/or secretion of exoenzymes to generate a level appropriate to exploit a given nutrient environment.

  14. Production and Characterization of a New Bacterial Cellulose/Poly(Vinyl Alcohol Nanocomposite

    Directory of Open Access Journals (Sweden)

    Miguel Gama

    2013-05-01

    Full Text Available Bacterial cellulose (BC is characterized for its high water holding capacity, high crystallinity, an ultrafine fiber network and high tensile strength. This work demonstrates the production of a new interpenetrated polymer network nanocomposite obtained through the incorporation of poly(vinyl alcohol (PVA on the BC matrix and evaluates the effect of oven drying on the morphological, mechanical and mass transfer properties of the composite membranes. Both the addition of PVA and oven drying induce the appearance of larger pores (circa 1–3 µm in average diameter in dried BC/PVA membranes. Both types of treatments also affect the permeability of the composite, as assessed by the diffusion coefficients of polyethylene glycol (PEG molecules (900, 8,000, 35,000 and 100,000 Da across the membranes. Finally, the Young’s modulus of dry pristine BC decreases following PVA incorporation, resulting in a change from 3.5 GPa to 1 GPa and a five-fold loss in tensile strength.

  15. Production of fungal and bacterial growth modulating secondary metabolites is widespread among mycorrhiza-associated streptomycetes

    Science.gov (United States)

    2012-01-01

    Background Studies on mycorrhiza associated bacteria suggest that bacterial-fungal interactions play important roles during mycorrhiza formation and affect plant health. We surveyed Streptomyces Actinobacteria, known as antibiotic producers and antagonists of fungi, from Norway spruce mycorrhizas with predominantly Piloderma species as the fungal partner. Results Fifteen Streptomyces isolates exhibited substantial variation in inhibition of tested mycorrhizal and plant pathogenic fungi (Amanita muscaria, Fusarium oxysporum, Hebeloma cylindrosporum, Heterobasidion abietinum, Heterobasidion annosum, Laccaria bicolor, Piloderma croceum). The growth of the mycorrhiza-forming fungus Laccaria bicolor was stimulated by some of the streptomycetes, and Piloderma croceum was only moderately affected. Bacteria responded to the streptomycetes differently than the fungi. For instance the strain Streptomyces sp. AcM11, which inhibited most tested fungi, was less inhibitory to bacteria than other tested streptomycetes. The determined patterns of Streptomyces-microbe interactions were associated with distinct patterns of secondary metabolite production. Notably, potentially novel metabolites were produced by strains that were less antagonistic to fungi. Most of the identified metabolites were antibiotics (e.g. cycloheximide, actiphenol) and siderophores (e.g. ferulic acid, desferroxiamines). Plant disease resistance was activated by a single streptomycete strain only. Conclusions Mycorrhiza associated streptomycetes appear to have an important role in inhibiting the growth of fungi and bacteria. Additionally, our study indicates that the Streptomyces strains, which are not general antagonists of fungi, may produce still un-described metabolites. PMID:22852578

  16. Production of fungal and bacterial growth modulating secondary metabolites is widespread among mycorrhiza-associated streptomycetes

    Directory of Open Access Journals (Sweden)

    Schrey Silvia D

    2012-08-01

    Full Text Available Abstract Background Studies on mycorrhiza associated bacteria suggest that bacterial-fungal interactions play important roles during mycorrhiza formation and affect plant health. We surveyed Streptomyces Actinobacteria, known as antibiotic producers and antagonists of fungi, from Norway spruce mycorrhizas with predominantly Piloderma species as the fungal partner. Results Fifteen Streptomyces isolates exhibited substantial variation in inhibition of tested mycorrhizal and plant pathogenic fungi (Amanita muscaria, Fusarium oxysporum, Hebeloma cylindrosporum, Heterobasidion abietinum, Heterobasidion annosum, Laccaria bicolor, Piloderma croceum. The growth of the mycorrhiza-forming fungus Laccaria bicolor was stimulated by some of the streptomycetes, and Piloderma croceum was only moderately affected. Bacteria responded to the streptomycetes differently than the fungi. For instance the strain Streptomyces sp. AcM11, which inhibited most tested fungi, was less inhibitory to bacteria than other tested streptomycetes. The determined patterns of Streptomyces-microbe interactions were associated with distinct patterns of secondary metabolite production. Notably, potentially novel metabolites were produced by strains that were less antagonistic to fungi. Most of the identified metabolites were antibiotics (e.g. cycloheximide, actiphenol and siderophores (e.g. ferulic acid, desferroxiamines. Plant disease resistance was activated by a single streptomycete strain only. Conclusions Mycorrhiza associated streptomycetes appear to have an important role in inhibiting the growth of fungi and bacteria. Additionally, our study indicates that the Streptomyces strains, which are not general antagonists of fungi, may produce still un-described metabolites.

  17. Legacy effects of anaerobic soil disinfestation on soil bacterial community composition and production of pathogen-suppressing volatiles

    Directory of Open Access Journals (Sweden)

    Maaike evan Agtmaal

    2015-07-01

    Full Text Available There is increasing evidence that microbial volatiles (VOCs play an important role in natural suppression of soil-borne diseases, but little is known on the factors that influence production of suppressing VOCs. In the current study we examined whether a stress-induced change in soil microbial community composition would affect the production by soils of VOCs suppressing the plant-pathogenic oomycete Pythium. Using pyrosequencing of 16S ribosomal gene fragments we compared the composition of bacterial communities in sandy soils that had been exposed to anaerobic disinfestation (AD, a treatment used to kill harmful soil organisms, with the composition in untreated soils. Three months after the AD treatment had been finished, there was still a clear legacy effect of the former anaerobic stress on bacterial community composition with a strong increase in relative abundance of the phylum Bacteroidetes and a significant decrease of the phyla Acidobacteria, Planctomycetes, Nitrospirae, Chloroflexi and Chlorobi. This change in bacterial community composition coincided with loss of production of Pythium suppressing soil volatiles (VOCs and of suppression of Pythium impacts on Hyacinth root development. One year later, the composition of the bacterial community in the AD soils was reflecting that of the untreated soils. In addition, both production of Pythium-suppressing VOCs and suppression of Pythium in Hyacinth bioassays had returned to the levels of the untreated soil. GC/MS analysis identified several VOCs, among which compounds known to be antifungal, that were produced in the untreated soils but not in the AD soils. These compounds were again produced 15 months after the AD treatment. Our data indicate that soils exposed to a drastic stress can temporarily lose pathogen suppressive characteristics and that both loss and return of these suppressive characteristics coincides with shifts in the soil bacterial community composition. Our data are

  18. Thermodynamics Prediction of Wax Precipitation in Black Oil Using Regular Solution Model and Plus Fraction Characterization

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2013-01-01

    Full Text Available The precipitation of wax/solid paraffin during production, transportation, and processing of crude oil is a serious problem. It is essential to have a reliable model to predict the wax appearance temperature and the amount of solid precipitated at different conditions. This paper presents a work to predict the solid precipitation based on solid-liquid equilibrium with regular solution-molecular thermodynamic theory and characterization of the crude oil plus fraction. Due to the differences of solubility characteristics between solid and liquid phase, the solubility parameters of liquid and solid phase are calculated by a modified model. The heat capacity change between solid and liquid phase is considered and estimated in the thermodynamic model. An activity coefficient based thermodynamic method combined with two characteristic methods to calculate wax precipitation in crude oil, especially heavy oil, has been tested with experimental data. The results show that the wax appearance temperature and the amount of weight precipitated can be predicted well with the experimental data.

  19. A prediction method for the wax deposition rate based on a radial basis function neural network

    Directory of Open Access Journals (Sweden)

    Ying Xie

    2017-06-01

    Full Text Available The radial basis function neural network is a popular supervised learning tool based on machinery learning technology. Its high precision having been proven, the radial basis function neural network has been applied in many areas. The accumulation of deposited materials in the pipeline may lead to the need for increased pumping power, a decreased flow rate or even to the total blockage of the line, with losses of production and capital investment, so research on predicting the wax deposition rate is significant for the safe and economical operation of an oil pipeline. This paper adopts the radial basis function neural network to predict the wax deposition rate by considering four main influencing factors, the pipe wall temperature gradient, pipe wall wax crystal solubility coefficient, pipe wall shear stress and crude oil viscosity, by the gray correlational analysis method. MATLAB software is employed to establish the RBF neural network. Compared with the previous literature, favorable consistency exists between the predicted outcomes and the experimental results, with a relative error of 1.5%. It can be concluded that the prediction method of wax deposition rate based on the RBF neural network is feasible.

  20. Rapid atmospheric transport and large-scale deposition of recently synthesized plant waxes

    Science.gov (United States)

    Nelson, Daniel B.; Ladd, S. Nemiah; Schubert, Carsten J.; Kahmen, Ansgar

    2018-02-01

    Sedimentary plant wax 2H/1H ratios are important tools for understanding hydroclimate and environmental changes, but large spatial and temporal uncertainties exist about transport mechanisms from ecosystem to sediments. To assess atmospheric pathways, we collected aerosol samples for two years at four locations within a ∼60 km radius in northern Switzerland. We measured n-alkane distributions and 2H/1H ratios in these samples, and from local plants, leaf litter, and soil, as well as surface sediment from six nearby lakes. Increased concentrations and 2H depletion of long odd chain n-alkanes in early summer aerosols indicate that most wax aerosol production occurred shortly after leaf unfolding, when plants synthesize waxes in large quantities. During autumn and winter, aerosols were characterized by degraded n-alkanes lacking chain length preferences diagnostic of recent biosynthesis, and 2H/1H values that were in some cases more than 100‰ higher than growing season values. Despite these seasonal shifts, modeled deposition-weighted average 2H/1H values of long odd chain n-alkanes primarily reflected summer values. This was corroborated by n-alkane 2H/1H values in lake sediments, which were similar to deposition-weighted aerosol values at five of six sites. Atmospheric deposition rates for plant n-alkanes on land were ∼20% of accumulation rates in lakes, suggesting a role for direct deposition to lakes or coastal oceans near similar production sources, and likely a larger role for deposition on land and transport in river systems. This mechanism allows mobilization and transport of large quantities of recently produced waxes as fine-grained material to low energy sedimentation sites over short timescales, even in areas with limited topography. Widespread atmospheric transfer well before leaf senescence also highlights the importance of the isotopic composition of early season source water used to synthesize waxes for the geologic record.

  1. A review on wax printed microfluidic paper-based devices for international health.

    Science.gov (United States)

    Altundemir, S; Uguz, A K; Ulgen, K

    2017-07-01

    Paper-based microfluidics has attracted attention for the last ten years due to its advantages such as low sample volume requirement, ease of use, portability, high sensitivity, and no necessity to well-equipped laboratory equipment and well-trained manpower. These characteristics have made paper platforms a promising alternative for a variety of applications such as clinical diagnosis and quantitative analysis of chemical and biological substances. Among the wide range of fabrication methods for microfluidic paper-based analytical devices ( μ PADs), the wax printing method is suitable for high throughput production and requires only a commercial printer and a heating source to fabricate complex two or three-dimensional structures for multipurpose systems. μ PADs can be used by anyone for in situ diagnosis and analysis; therefore, wax printed μ PADs are promising especially in resource limited environments where people cannot get sensitive and fast diagnosis of their serious health problems and where food, water, and related products are not able to be screened for toxic elements. This review paper is focused on the applications of paper-based microfluidic devices fabricated by the wax printing technique and used for international health. Besides presenting the current limitations and advantages, the future directions of this technology including the commercial aspects are discussed. As a conclusion, the wax printing technology continues to overcome the current limitations and to be one of the promising fabrication techniques. In the near future, with the increase of the current interest of the industrial companies on the paper-based technology, the wax-printed paper-based platforms are expected to take place especially in the healthcare industry.

  2. Denitrifying bacterial communities affect current production and nitrous oxide accumulation in a microbial fuel cell.

    Science.gov (United States)

    Vilar-Sanz, Ariadna; Puig, Sebastià; García-Lledó, Arantzazu; Trias, Rosalia; Balaguer, M Dolors; Colprim, Jesús; Bañeras, Lluís

    2013-01-01

    The biocathodic reduction of nitrate in Microbial Fuel Cells (MFCs) is an alternative to remove nitrogen in low carbon to nitrogen wastewater and relies entirely on microbial activity. In this paper the community composition of denitrifiers in the cathode of a MFC is analysed in relation to added electron acceptors (nitrate and nitrite) and organic matter in the cathode. Nitrate reducers and nitrite reducers were highly affected by the operational conditions and displayed high diversity. The number of retrieved species-level Operational Taxonomic Units (OTUs) for narG, napA, nirS and nirK genes was 11, 10, 31 and 22, respectively. In contrast, nitrous oxide reducers remained virtually unchanged at all conditions. About 90% of the retrieved nosZ sequences grouped in a single OTU with a high similarity with Oligotropha carboxidovorans nosZ gene. nirS-containing denitrifiers were dominant at all conditions and accounted for a significant amount of the total bacterial density. Current production decreased from 15.0 A · m(-3) NCC (Net Cathodic Compartment), when nitrate was used as an electron acceptor, to 14.1 A · m(-3) NCC in the case of nitrite. Contrarily, nitrous oxide (N2O) accumulation in the MFC was higher when nitrite was used as the main electron acceptor and accounted for 70% of gaseous nitrogen. Relative abundance of nitrite to nitrous oxide reducers, calculated as (qnirS+qnirK)/qnosZ, correlated positively with N2O emissions. Collectively, data indicate that bacteria catalysing the initial denitrification steps in a MFC are highly influenced by main electron acceptors and have a major influence on current production and N2O accumulation.

  3. Wax Impaction in Nigerian School Children. | Eziyi | East and ...

    African Journals Online (AJOL)

    Background: Impacted wax has been classified as an ear disease. It can cause pain, itching, tinnitus hearing loss or otitis externa. The prevalence of cerumen impaction varies. The aim of this study was to determine the prevalence of impacted ear wax in primary school children and to determine, if there is any association ...

  4. Wax combs mediate nestmate recognition by guard honeybees

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Wenseleers, Tom; Dawson, Jenny

    2006-01-01

    Research has shown that the wax combs are important in the acquisition of colony odour in the honeybee, Apis mellifera. However, many of these studies were conducted in the laboratory or under artificial conditions. We investigated the role of the wax combs in nestmate recognition in the natural...

  5. Gluconeogenesis from storage wax in the cotyledons of jojoba seedlings.

    Science.gov (United States)

    Moreau, R A; Huang, A H

    1977-08-01

    The cotyledons of jojoba (Simmondsia chinensis) seeds contained 50 to 60% of their weight as intracellular wax esters. During germination there was a gradual decrease in the wax content with a concomitant rise in soluble carbohydrates, suggesting that the wax played the role of a food reserve. Thin layer chromatography revealed that both the fatty alcohol and fatty acid were metabolized. The disappearance of wax was matched with an increase of catalase, a marker enzyme of the gluconeogenic process in other fatty seedlings. Subcellular organelles were isolated by sucrose gradient centrifugation from the cotyledons at the peak stage of germination. The enzymes of the beta oxidation of fatty acid and of the glyoxylate cycle were localized in the glyoxysomes but not in the mitochondria. The glyoxysomes had specific activities of individual enzymes similar to those of the castor bean glyoxysomes. An active alkaline lipase was detected in the wax bodies at the peak stage of germination but not in the ungerminated seeds. No lipase was detected in glyoxysomes or mitochondria. After the wax in the wax bodies had been extracted with diethyl ether, the organelle membrane was isolated and it still retained the alkaline lipase. The gluconeogenesis from wax in the jojoba seedling appears to be similar, but with modification, to that from triglyceride in other fatty seedlings.

  6. Statistical Optimization of Sustained Release Venlafaxine HCI Wax Matrix Tablet.

    Science.gov (United States)

    Bhalekar, M R; Madgulkar, A R; Sheladiya, D D; Kshirsagar, S J; Wable, N D; Desale, S S

    2008-01-01

    The purpose of this research was to prepare a sustained release drug delivery system of venlafaxine hydrochloride by using a wax matrix system. The effects of bees wax and carnauba wax on drug release profile was investigated. A 3(2) full factorial design was applied to systemically optimize the drug release profile. Amounts of carnauba wax (X(1)) and bees wax (X(2)) were selected as independent variables and release after 12 h and time required for 50% (t(50)) drug release were selected as dependent variables. A mathematical model was generated for each response parameter. Both waxes retarded release after 12 h and increases the t(50) but bees wax showed significant influence. The drug release pattern for all the formulation combinations was found to be approaching Peppas kinetic model. Suitable combination of two waxes provided fairly good regulated release profile. The response surfaces and contour plots for each response parameter are presented for further interpretation of the results. The optimum formulations were chosen and their predicted results found to be in close agreement with experimental findings.

  7. Influence of Different Waxes on the Physical Properties of Linear ...

    African Journals Online (AJOL)

    NJD

    2005-12-22

    Dec 22, 2005 ... viscosity of a polymer melt. In many instances it ... amounts of different waxes on the viscosity (melt flow) of ..... Since the MFI is a direct measure of the viscosity .... melt flow index increasing with increasing wax content. There.

  8. Biochemical response of sweet potato to bemul-wax coating ...

    African Journals Online (AJOL)

    Sweet potato (Ipomoea batatas Linn) tuber is a very nutritious but highly perishable crop that is subject to high wastages due to non-availability of appropriate storage techniques. This work assessed the effectiveness of treating the tubers with calcium chloride dip (CCD), bemul-wax (B-wax) and their combinations ...

  9. HIF-1α is essential for effective PMN bacterial killing, antimicrobial peptide production and apoptosis in Pseudomonas aeruginosa keratitis.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Berger

    Full Text Available Hypoxia-inducible factor (HIF-1α, is a transcription factor that controls energy metabolism and angiogenesis under hypoxic conditions, and a potent regulator of innate immunity. The studies described herein examined the role of HIF-1α in disease resolution in BALB/c (resistant, cornea heals mice after ocular infection with Pseudomonas (P. aeruginosa. Furthermore, the current studies focused on the neutrophil (PMN, the predominant cell infiltrate in keratitis. Using both siRNA and an antagonist (17-DMAG, the role of HIF-1α was assessed in P. aeruginosa-infected BALB/c mice. Clinical score and slit lamp photography indicated HIF-1α inhibition exacerbated disease and corneal destruction. Real time RT-PCR, immunohistochemistry, ELISA, Greiss and MPO assays, bacterial load, intracellular killing, phagocytosis and apoptosis assays further tested the regulatory role of HIF-1α. Despite increased pro-inflammatory cytokine expression and increased MPO levels after knocking down HIF-1α expression, in vivo studies revealed a decrease in NO production and higher bacterial load. In vitro studies using PMN provided evidence that although inhibition of HIF-1α did not affect phagocytosis, both bacterial killing and apoptosis were significantly affected, as was production of antimicrobial peptides. Overall, data provide evidence that inhibition of HIF-1α converts a normally resistant disease response to susceptible (corneal thinning and perforation after induction of bacterial keratitis. Although this inhibition does not appear to affect PMN transmigration or phagocytosis, both in vivo and in vitro approaches indicate that the transcriptional factor is essential for effective bacterial killing, apoptosis and antimicrobial peptide production.

  10. Hybrid combinations containing natural products and antimicrobial drugs that interfere with bacterial and fungal biofilms.

    Science.gov (United States)

    Zacchino, Susana A; Butassi, Estefanía; Cordisco, Estefanía; Svetaz, Laura A

    2017-12-15

    works respectively. Regarding combinations against bacterial biofilms, in vitro studies were performed in all works by using several different methods of higher variety than the used against fungal biofilms. Biofilms of both the gram (+) and gram (-) bacteria were prepared, although biofilm of Staphylococcus spp. were the most used in the collected works. Among the discovered potentiators of antibacterial drugs, 75% were terpenes, including mono, di- and triterpenes, and, among the atibacterial drugs, several structurally diverse types were used in the combinations: aminoglycosides, β-lactams, glucopeptides and fluoroquinolones. The potentiating capacity of natural products, mainly terpenes, on the antibiofilm effect of antimicrobial drugs opens a wide range of possibilities for the combination antimicrobial therapy. More in vivo studies on combinations of natural products with antimicrobial drugs acting against biofilms are highly required to cope the difficult to treat biofilm-associated infections. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Pickering emulsions stabilized by paraffin wax and Laponite clay particles.

    Science.gov (United States)

    Li, Caifu; Liu, Qian; Mei, Zhen; Wang, Jun; Xu, Jian; Sun, Dejun

    2009-08-01

    Emulsions containing wax in dispersed droplets stabilized by disc-like Laponite clay particles are prepared. Properties of the emulsions prepared at different temperatures are examined using stability, microscopy and droplet-size analysis. At low temperature, the wax crystals in the oil droplets can protrude through the interface, leading to droplet coalescence. But at higher temperatures, the droplet size decreases with wax concentration. Considering the viscosity of the oil phase and the interfacial tension, we conclude that the wax is liquid-like during the high temperature emulsification process, but during cooling wax crystals appear around the oil/water interface and stabilize the droplets. The oil/water ratio has minimal effect on the emulsions between ratios of 3:7 and 7:3. The Laponite is believed to stabilize the emulsions by increasing the viscosity of the continuous phase and also by adsorbing at the oil/water interface, thus providing a physical barrier to coalescence.

  12. From rotten grapes to industrial exploitation: Komagataeibacter europaeus SGP37, a micro-factory for macroscale production of bacterial nanocellulose.

    Science.gov (United States)

    Dubey, Swati; Sharma, Raj Kumar; Agarwal, Pragati; Singh, Jyoti; Sinha, Neeraj; Singh, R P

    2017-03-01

    Bacterial nanocellulose (BNC), being ultrapure and unique in its properties, is a booming and ageless precursor of several breakthrough technologies of materials sciences; however, its low yield and high cost has created a challenge for its usage at industrial level. Herein, we report a novel, high yielding bacterial cell factory Komagataeibacter europaeus SGP37, isolated from rotten grapes, for the production of high quality and value added BNC. The strain was kinetically analyzed to evaluate BNC production under different physiological conditions and had demonstrated the production of 9.98±0.24gL -1 BNC at the expense of 12.08±1.94gL -1 sugar following 2 weeks of cultivation, thus having the conversion yield of 0.82g BNC/g sugar which seems to be the maximum reported yield so far. The analysis of produced pellicle using FTIR, 13 C CP MAS NMR, FE-SEM, XRD and TGA had shown similar structural, morphological and chemical characteristics with that of bacterial nanocellulose. Thus, K. europaeus SGP37 appears to be a potential strain and may offer a promising platform for industrial scale production of nanocelluloses. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Bacterial Infection of Fly Ovaries Reduces Egg Production and Induces Local Hemocyte Activation

    Science.gov (United States)

    Brandt, Stephanie M.; Schneider, David S.

    2009-01-01

    Summary Morbidity, the state of being diseased, is an important aspect of pathogenesis that has gone relatively unstudied in fruit flies. Our interest is in characterizing how bacterial pathogenesis affects various physiologies of the fly. We chose to examine the fly ovary because we found bacterial infection had a striking effect on fly reproduction. We observed decreased egg laying after bacterial infection that correlated with increased bacterial virulence. We also found that bacteria colonized the ovary in a previously undescribed manner; bacteria were found in the posterior of the ovary, adjacent to the lateral oviduct. This local infection in the ovary resulted in melanization and activation of the cellular immune response at the site of infection. PMID:17400292

  14. Development of a Low Input and sustainable Switchgrass Feedstock Production System Utilizing Beneficial Bacterial Endophytes

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Chuansheng [IALR; Nowak, Jerzy [VPISU; Seiler, John [VPISU

    2014-10-24

    Switchgrass represents a promising feedstock crop for US energy sustainability. However, its broad utilization for bioenergy requires improvements of biomass yields and stress tolerance. In this DOE funded project, we have been working on harnessing beneficial bacterial endophytes to enhance switchgrass performance and to develop a low input feedstock production system for marginal lands that do not compete with the production of food crops. We have demonstrated that one of most promising plant growth-promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize roots and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, greenhouse, as well as field conditions. Furthermore, PsJN bacterization improved growth and development of switchgrass seedlings, significantly stimulated plant root and shoot growth, and tiller number in the field, and enhanced biomass accumulation on both poor (p<0.001) and rich (p<0.05) soils, with more effective stimulation of plant growth in low fertility soil. Plant physiology measurements showed that PsJN inoculated Alamo had consistently lower transpiration, lower stomatal conductance, and higher water use efficiency in greenhouse conditions. These physiological changes may significantly contribute to the recorded growth enhancement. PsJN inoculation rapidly results in an increase in photosynthetic rates which contributes to the advanced growth and development. Some evidence suggests that this initial growth advantage decreases with time when resources are not limited such as in greenhouse studies. Additionally, better drought resistance and drought hardening were observed in PsJN inoculated switchgrass. Using the DOE-funded switchgrass EST microarray, in a collaboration with the Genomics Core Facility at the Noble Foundation, we have determined gene expression profile changes in both responsive switchgrass cv. Alamo and non-responsive cv. Cave-in-Rock (CR) following Ps

  15. Organic loading rates affect composition of soil-derived bacterial communities during continuous, fermentative biohydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yonghua; Bruns, Mary Ann [Department of Crop and Soil Sciences, The Pennsylvania State University, University Park, PA 16802 (United States); Zhang, Husen; Salerno, Michael; Logan, Bruce E. [Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA 16802 (United States)

    2008-11-15

    Bacterial community composition during steady-state, fermentative H{sub 2} production was compared across a range of organic loading rates (OLRs) of 0.5-19 g COD l{sup -1} h{sup -1} in a 2-l continuous flow reactor at 30 C. The varied OLRs were achieved with glucose concentrations of 2.5-10 g l{sup -1} and hydraulic retention times of 1-10 h. The synthetic wastewater feed was amended with L-cysteine and maintained at a pH of 5.5. For each run at a given glucose concentration, the reactor was inoculated with an aliquot of well-mixed agricultural topsoil that had been heat-treated to reduce numbers of vegetative cells. At OLRs less than 2 g COD l{sup -1} h{sup -1}, DNA sequences from ribosomal RNA intergenic spacer analysis profiles revealed more diverse and variable populations (Selenomonas, Enterobacter, and Clostridium spp.) than were observed above 2 g COD l{sup -1} h{sup -1} (Clostridium spp. only). An isolate, LYH1, was cultured from a reactor sample (10 g glucose l{sup -1} at a 10-h HRT) on medium containing L-cysteine. In confirming H{sub 2} production by LYH1 in liquid batch culture, lag periods for H{sub 2} production in the presence and absence of L-cysteine were 5 and 50 h, respectively. The 16S rRNA gene sequence of LYH1 indicated that the isolate was a Clostridium sp. affiliated with RNA subcluster Ic, with >99% similarity to Clostridium sp. FRB1. In fluorescent in situ hybridization tests, an oligonucleotide probe complementary to the 16S rRNA of LYH1 hybridized with 90% of cells observed at an OLR of 2 g COD h{sup -1}, compared to 26% of cells at an OLR of 0.5 g COD l{sup -1} h{sup -1}. An OLR of 2 g COD l{sup -1} h{sup -1} appeared to be a critical threshold above which clostridia were better able to outcompete Enterobacteriaceae and other organisms in the mixed soil inoculum. Our results are discussed in light of other biohydrogen studies employing pure cultures and mixed inocula. (author)

  16. Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

    Directory of Open Access Journals (Sweden)

    Esko Petäjä

    1993-09-01

    Full Text Available This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C. The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.

  17. Using the overlay assay to qualitatively measure bacterial production of and sensitivity to pneumococcal bacteriocins.

    Science.gov (United States)

    Maricic, Natalie; Dawid, Suzanne

    2014-09-30

    Streptococcus pneumoniae colonizes the highly diverse polymicrobial community of the nasopharynx where it must compete with resident organisms. We have shown that bacterially produced antimicrobial peptides (bacteriocins) dictate the outcome of these competitive interactions. All fully-sequenced pneumococcal strains harbor a bacteriocin-like peptide (blp) locus. The blp locus encodes for a range of diverse bacteriocins and all of the highly conserved components needed for their regulation, processing, and secretion. The diversity of the bacteriocins found in the bacteriocin immunity region (BIR) of the locus is a major contributor of pneumococcal competition. Along with the bacteriocins, immunity genes are found in the BIR and are needed to protect the producer cell from the effects of its own bacteriocin. The overlay assay is a quick method for examining a large number of strains for competitive interactions mediated by bacteriocins. The overlay assay also allows for the characterization of bacteriocin-specific immunity, and detection of secreted quorum sensing peptides. The assay is performed by pre-inoculating an agar plate with a strain to be tested for bacteriocin production followed by application of a soft agar overlay containing a strain to be tested for bacteriocin sensitivity. A zone of clearance surrounding the stab indicates that the overlay strain is sensitive to the bacteriocins produced by the pre-inoculated strain. If no zone of clearance is observed, either the overlay strain is immune to the bacteriocins being produced or the pre-inoculated strain does not produce bacteriocins. To determine if the blp locus is functional in a given strain, the overlay assay can be adapted to evaluate for peptide pheromone secretion by the pre-inoculated strain. In this case, a series of four lacZ-reporter strains with different pheromone specificity are used in the overlay.

  18. Optimization of Culture Parameters for Maximum Polyhydroxybutyrate Production by Selected Bacterial Strains Isolated from Rhizospheric Soils.

    Science.gov (United States)

    Lathwal, Priyanka; Nehra, Kiran; Singh, Manpreet; Jamdagni, Pragati; Rana, Jogender S

    2015-01-01

    The enormous applications of conventional non-biodegradable plastics have led towards their increased usage and accumulation in the environment. This has become one of the major causes of global environmental concern in the present century. Polyhydroxybutyrate (PHB), a biodegradable plastic is known to have properties similar to conventional plastics, thus exhibiting a potential for replacing conventional non-degradable plastics. In the present study, a total of 303 different bacterial isolates were obtained from soil samples collected from the rhizospheric area of three crops, viz., wheat, mustard and sugarcane. All the isolates were screened for PHB (Poly-3-hydroxy butyric acid) production using Sudan Black staining method, and 194 isolates were found to be PHB positive. Based upon the amount of PHB produced, the isolates were divided into three categories: high, medium and low producers. Representative isolates from each category were selected for biochemical characterization; and for optimization of various culture parameters (carbon source, nitrogen source, C/N ratio, different pH, temperature and incubation time periods) for maximizing PHB accumulation. The highest PHB yield was obtained when the culture medium was supplemented with glucose as the carbon source, ammonium sulphate at a concentration of 1.0 g/l as the nitrogen source, and by maintaining the C/N ratio of the medium as 20:1. The physical growth parameters which supported maximum PHB accumulation included a pH of 7.0, and an incubation temperature of 30 degrees C for a period of 48 h. A few isolates exhibited high PHB accumulation under optimized conditions, thus showing a potential for their industrial exploitation.

  19. Development of Wax-Incorporated Emulsion Gel Beads for the Encapsulation and Intragastric Floating Delivery of the Active Antioxidant from Tamarindus indica L.

    Science.gov (United States)

    Soradech, Sitthiphong; Petchtubtim, Intira; Thongdon-A, Jeerayu; Muangman, Thanchanok

    2016-03-22

    In this study, tamarind (Tamarindus indica L.) seed extracts with potential antioxidant activity and toxicity to cancer cells were developed as functional foods and nutraceutical ingredients in the form of emulsion gel beads. Three extracts were obtained from ethanol and water: TSCH50, TSCH95 and TSCH. All extracts exhibited high potential for superoxide anion scavenging activity over the IC50 range emulsion gel beads, which were prepared using a modified ionotropic gelation technique. Tamarind seed extract at 1% (w/w) was used as the active ingredient in all formulations. The effect of the types and amounts of wax on the encapsulation efficiency and percentage of the active release of alginate gel beads was also investigated. The results demonstrated that the incorporation of both waxes into the gel beads had an effect on the percentage of encapsulation efficiency (%) and the percentage of the active ingredient release. Furthermore, the addition of water insoluble waxes (carnauba and bee wax) significantly retarded the release of the active ingredient. The addition of both waxes had a slight effect on drug release behavior. Nevertheless, the increase in incorporated waxes in all formulations could sustain the percentage of active ingredient release. In conclusion, wax-incorporated emulsion gel beads using a modified ionotropic gelation technique could be applied for the intragastric floating delivery and controlled release of functional food and nutraceutical products for their antioxidant and anticancer capacity.

  20. Community respiration/production and bacterial activity in the upper water column of the central Arctic Ocean

    Science.gov (United States)

    Sherr, Barry F.; Sherr, Evelyn B.

    2003-04-01

    Community metabolism (respiration and production) and bacterial activity were assessed in the upper water column of the central Arctic Ocean during the SHEBA/JOIS ice camp experiment, October 1997-September 1998. In the upper 50 m, decrease in integrated dissolved oxygen (DO) stocks over a period of 124 d in mid-winter suggested a respiration rate of ˜3.3 nM O 2 h -1 and a carbon demand of ˜4.5 gC m -2. Increase in 0-50 m integrated stocks of DO during summer implied a net community production of ˜20 gC m -2. Community respiration rates were directly measured via rate of decrease in DO in whole seawater during 72-h dark incubation experiments. Incubation-based respiration rates were on average 3-fold lower during winter (11.0±10.6 nM O 2 h -1) compared to summer (35.3±24.8 nM O 2 h -1). Bacterial heterotrophic activity responded strongly, without noticeable lag, to phytoplankton growth. Rate of leucine incorporation by bacteria (a proxy for protein synthesis and cell growth) increased ˜10-fold, and the cell-specific rate of leucine incorporation ˜5-fold, from winter to summer. Rates of production of bacterial biomass in the upper 50 m were, however, low compared to other oceanic regions, averaging 0.52±0.47 ngC l -1 h -1 during winter and 5.1±3.1 ngC l -1 h -1 during summer. Total carbon demand based on respiration experiments averaged 2.4±2.3 mgC m -3 d -1 in winter and 7.8±5.5 mgC m -3 d -1 in summer. Estimated bacterial carbon demand based on bacterial productivity and an assumed 10% gross growth efficiency was much lower, averaging about 0.12±0.12 mgC m -3 d -1 in winter and 1.3±0.7 mgC m -3 d -1 in summer. Our estimates of bacterial activity during summer were an order of magnitude less than rates reported from a summer 1994 study in the central Arctic Ocean, implying significant inter-annual variability of microbial processes in this region.

  1. Purifying oils and waxes. [British patent

    Energy Technology Data Exchange (ETDEWEB)

    1926-01-27

    Fractions of petroleum, shale oil, coal oil, and paraffin wax are refined by passing the vapour under reduced pressure through fuller's earth, bauxite, silica gel, or other adsorbent at a temperature not substantially more than sufficient to maintain the vapour phase. The vapour may be passed in succession through adsorbent of increasing strength. Treatment with sulphuric acid, or with alkali, or with both may precede treatment with absorbent, and this successive treatment may be repeated any number of times. The action is accelerated by passing a current of inert gas insufficient to affect the vacuum materially along with the vapours. In an example a 160 to 225/sup 0/C kerosene fraction is treated with sulphuric acid of 10 percent strength, and passed into a fuller's earth chamber under a vacuum of 27 in. of mercury and heated by steam to about 140/sup 0/C. The apparatus is described.

  2. Production of Bacterial Cellulose by Gluconacetobacter hansenii Using Corn Steep Liquor As Nutrient Sources

    Directory of Open Access Journals (Sweden)

    Andrea F. S. Costa

    2017-10-01

    Full Text Available Cellulose is mainly produced by plants, although many bacteria, especially those belonging to the genus Gluconacetobacter, produce a very peculiar form of cellulose with mechanical and structural properties that can be exploited in numerous applications. However, the production cost of bacterial cellulose (BC is very high to the use of expensive culture media, poor yields, downstream processing, and operating costs. Thus, the purpose of this work was to evaluate the use of industrial residues as nutrients for the production of BC by Gluconacetobacter hansenii UCP1619. BC pellicles were synthesized using the Hestrin–Schramm (HS medium and alternative media formulated with different carbon (sugarcane molasses and acetylated glucose and nitrogen sources [yeast extract, peptone, and corn steep liquor (CSL]. A jeans laundry was also tested. None of the tested sources (beside CSL worked as carbon and nutrient substitute. The alternative medium formulated with 1.5% glucose and 2.5% CSL led to the highest yield in terms of dry and hydrated mass. The BC mass produced in the alternative culture medium corresponded to 73% of that achieved with the HS culture medium. The BC pellicles demonstrated a high concentration of microfibrils and nanofibrils forming a homogenous, compact, and three-dimensional structure. The biopolymer produced in the alternative medium had greater thermal stability, as degradation began at 240°C, while degradation of the biopolymer produced in the HS medium began at 195°C. Both biopolymers exhibited high crystallinity. The mechanical tensile test revealed the maximum breaking strength and the elongation of the break of hydrated and dry pellicles. The dry BC film supported up to 48 MPa of the breaking strength and exhibited greater than 96.98% stiffness in comparison with the hydrated film. The dry film supported up to 48 MPa of the breaking strength and exhibited greater than 96.98% stiffness in comparison with the hydrated film

  3. Impact of metal stress on the production of secondary metabolites in Pteris vittata L. and associated rhizosphere bacterial communities.

    Science.gov (United States)

    Pham, Hoang Nam; Michalet, Serge; Bodillis, Josselin; Nguyen, Tien Dat; Nguyen, Thi Kieu Oanh; Le, Thi Phuong Quynh; Haddad, Mohamed; Nazaret, Sylvie; Dijoux-Franca, Marie-Geneviève

    2017-07-01

    Plants adapt to metal stress by modifying their metabolism including the production of secondary metabolites in plant tissues. Such changes may impact the diversity and functions of plant associated microbial communities. Our study aimed to evaluate the influence of metals on the secondary metabolism of plants and the indirect impact on rhizosphere bacterial communities. We then compared the secondary metabolites of the hyperaccumulator Pteris vittata L. collected from a contaminated mining site to a non-contaminated site in Vietnam and identified the discriminant metabolites. Our data showed a significant increase in chlorogenic acid derivatives and A-type procyanidin in plant roots at the contaminated site. We hypothesized that the intensive production of these compounds could be part of the antioxidant defense mechanism in response to metals. In parallel, the structure and diversity of bulk soil and rhizosphere communities was studied using high-throughput sequencing. The results showed strong differences in bacterial composition, characterized by the dominance of Proteobacteria and Nitrospira in the contaminated bulk soil, and the enrichment of some potential human pathogens, i.e., Acinetobacter, Mycobacterium, and Cupriavidus in P. vittata's rhizosphere at the mining site. Overall, metal pollution modified the production of P. vittata secondary metabolites and altered the diversity and structure of bacterial communities. Further investigations are needed to understand whether the plant recruits specific bacteria to adapt to metal stress.

  4. The Effect of Paraffin Wax to Properties of Radiation Vulcanization Natural Rubber Latex (RVNRL)

    International Nuclear Information System (INIS)

    Mohd Noorwadi Mat Lazim; Sofian Ibrahim; Muhammad Saiful Omar

    2015-01-01

    Dipping factories often encounter a serious problem with high tackiness of the finish products during storage. The tackiness effect can be lead to rejection of products. This tackiness effect of natural (NR) rubber film originates in the free rubber chain ends at the surface of the film. The tackiness is not depends on the degree of crosslinking (vulcanization), since radiation itself unable to reduce the tackiness effect. The RVNRL requires addition of additive or anti-tack agent into formulation to reduce tackiness effect. In this experiment, paraffin wax manufactured by Emulco Sdn Bhd under the trade name Aquawax 48 was added into RVNRL formulation as anti-tack and the effect of paraffin wax to physical and mechanical properties of RVNRL was study. (author)

  5. Evaluation of bacterial flora during the ripening of Kedong sufu, a typical Chinese traditional bacteria-fermented soybean product.

    Science.gov (United States)

    Feng, Zhen; Gao, Wei; Ren, Dan; Chen, Xi; Li, Juan-juan

    2013-04-01

    Kedong sufu is a typical bacteria-fermented sufu in China. Isolation and identification of the autochthonous bacteria involved would allow the design of specific starters for this speciality. The purpose of the present study was to evaluate the bacterial flora during the ripening of Kedong sufu using polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) and culturing. In terms of bacterial diversity, 22 strains were isolated and identified and 27 strains were detected by DGGE. Regarding bacterial dynamics, the results of culturing and PCR-DGGE exhibited a similar trend towards dominant strains. Throughout the fermentation of sufu, Enterococcus avium, Enterococcus faecalis and Staphylococcus carnosus were the dominant microflora, while the secondary microflora comprised Leuconostoc mesenteroides, Staphylococcus saprophyticus, Streptococcus lutetiensis, Kocuria rosea, Kocuria kristinae, Bacillus pumilus, Bacillus cereus and Bacillus subtilis. This study is the first to reveal the bacterial flora during the ripening of Kedong sufu using both culture-dependent and culture-independent methods. This information will help in the design of autochthonous starter cultures for the production of Kedong sufu with desirable characteristic sensory profiles and shorter ripening times. © 2012 Society of Chemical Industry.

  6. Bacterial biomass in warm-core Gulf Stream ring 82-B: mesoscale distributions, temporal changes and production

    Science.gov (United States)

    Ducklow, Hugh

    1986-11-01

    The distribution of bacterioplankton biomass and productivity in warm-core Gulf Stream ring 82-B generally corresponded to the physical and dynamical structure of the ring. Mean cell volumes were uniform for 4 months, but were larger by a factor of 2-3 in the high velocity (frontal) region (HVR) near the ring edge. As a result of this gradient and higher abundances, water column biomass and production were highest in the front, which appeared to be a local maximum in those properties. In this regard bacterioplankton contrasted strongly to phytoplankton, which exhibited strong local maxima at the center of the ring in June. In April when the water column inside the ring was isothermal to 450 m, bacterial biomass and production were low and uniform to 250 and 50 m, respectively. Bacterioplankton responded dramatically to the vernal restratification of the ring. In June when the surface layer was characterized by a strong pycnocline at 10-40 m, bacterial biomass and production often had strong subsurface maxima, and were 3 and 5 times greater than in April, respectively. Abundance exceeded 1.5 × 10 9 cells l -1 at ring center and exceeded 3 × 10 9 l -1 in the HVR. Turnover rates for the euphotic zone bacterioplankton as a whole were 0.24 d -1 in April, 0.56 d -1 in June, and 0.27 d -1 in August at ring center. Bacterial production averaged 12% of hourly primary production (range 1-32%), suggesting that bacteria control a significant and sometimes large portion of the carbon cycling in the euphotic zone. These data suggest that warm-core rings are sites of enhanced variability of bacterioplankton properties in the open sea. Furthermore, the data strongly support recent work showing that frontal zones are sites of locally enhanced bacterial biomass and production. In the ring system as a whole, the euphotic zone bacterioplankton biomass and production were comparable to and occasionally greater than the biomass and production of the >64 μm zooplankton, especially in

  7. Plant surface wax affects parasitoid's response to host footprints

    Science.gov (United States)

    Rostás, Michael; Ruf, Daniel; Zabka, Vanessa; Hildebrandt, Ulrich

    2008-10-01

    The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants ( cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones.

  8. Controls on bacterial and archaeal community structure and greenhouse gas production in natural, mined, and restored Canadian peatlands

    Directory of Open Access Journals (Sweden)

    Nathan eBasiliko

    2013-07-01

    Full Text Available Northern peatlands are important global C reservoirs, largely because of their slow rates of microbial C mineralization. Particularly in sites that are heavily influenced by anthropogenic disturbances, there is scant information about microbial ecology and whether or not microbial community structure influences greenhouse gas production. This work characterized communities of bacteria and archaea using terminal restriction fragment length polymorphism and sequence analysis of 16S rRNA and functional genes across eight natural, mined, or restored peatlands in two locations in eastern Canada. Correlations were explored among chemical properties of peat, bacterial and archaeal community structure, and carbon dioxide and methane production rates under oxic and anoxic conditions. Bacteria and archaea similar to those found in other peat soil environments were detected. In contrast to other reports, methanogen diversity was low in our study, with only 2 groups of known or suspected methanogens. Although mining and restoration affected substrate availability and microbial activity, these land-uses did not consistently affect bacterial or archaeal community composition. In fact, larger differences were observed between the two locations and between oxic and anoxic peat samples than between mined and restored sites, with anoxic samples characterized by less detectable bacterial diversity and stronger dominance by members of the phylum Acidobacteria. There were also no apparent strong linkages between prokaryote community structure and methane or carbon dioxide production, suggesting that different organisms exhibit functional redundancy and/or that the same taxa function at very different rates when exposed to different peat substrates. In contrast to other earlier work focusing on fungal communities across similar mined and restored peatlands, bacterial and archaeal communities appeared to be more resistant or resilient to peat substrate changes brought

  9. The Preparation and Performances of Self-Dispersed Nanomicron Emulsified Wax Solid Lubricant Ewax for Drilling Fluids

    Directory of Open Access Journals (Sweden)

    Feng-shan Zhou

    2014-01-01

    Full Text Available An oil-in-water nanomicron wax emulsion with oil phase content 45 wt% was prepared by using the emulsifying method of surfactant-in-oil. The optimum prepared condition is 85°C, 20 min, and 5 wt% complex emulsifiers. Then the abovementioned nanomicron emulsifying wax was immersed into a special water-soluble polymer in a certain percentage by the semidry technology. At last, a solidified self-dispersed nanomicron emulsified wax named as Ewax, a kind of solid lubricant for water based drilling fluid, was obtained after dried in the special soluble polymer containing emulsifying wax in low temperature. It is shown that the adhesion coefficient reduced rate (ΔKf is 73.5% and the extreme pressure (E-P friction coefficient reduced rate (Δf is 77.6% when the produced Ewax sample was added to fresh water based drilling fluid at dosage 1.0 wt%. In comparison with other normal similar liquid products, Ewax not only has better performances of lubrication, filtration loss control property, heat resistance, and tolerance to salt and is environmentally friendly, but also can solve the problems of freezing in the winter and poor storage stability of liquid wax emulsion in oilfield applications.

  10. Exploiting the aerobic endospore-forming bacterial diversity in saline and hypersaline environments for biosurfactant production.

    Science.gov (United States)

    de Almeida Couto, Camila Rattes; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Azevedo Jurelevicius, Diogo; Seldin, Lucy

    2015-10-28

    Biosurfactants are surface-active biomolecules with great applicability in the food, pharmaceutical and oil industries. Endospore-forming bacteria, which survive for long periods in harsh environments, are described as biosurfactant producers. Although the ubiquity of endospore-forming bacteria in saline and hypersaline environments is well known, studies on the diversity of the endospore-forming and biosurfactant-producing bacterial genera/species in these habitats are underrepresented. In this study, the structure of endospore-forming bacterial communities in sediment/mud samples from Vermelha Lagoon, Massambaba, Dois Rios and Abraão Beaches (saline environments), as well as the Praia Seca salterns (hypersaline environments) was determined via denaturing gradient gel electrophoresis. Bacterial strains were isolated from these environmental samples and further identified using 16S rRNA gene sequencing. Strains presenting emulsification values higher than 30 % were grouped via BOX-PCR, and the culture supernatants of representative strains were subjected to high temperatures and to the presence of up to 20 % NaCl to test their emulsifying activities in these extreme conditions. Mass spectrometry analysis was used to demonstrate the presence of surfactin. A diverse endospore-forming bacterial community was observed in all environments. The 110 bacterial strains isolated from these environmental samples were molecularly identified as belonging to the genera Bacillus, Thalassobacillus, Halobacillus, Paenibacillus, Fictibacillus and Paenisporosarcina. Fifty-two strains showed emulsification values of at least 30%, and they were grouped into 18 BOX groups. The stability of the emulsification values varied when the culture supernatants of representative strains were subjected to high temperatures and to the presence of up to 20% NaCl. The presence of surfactin was demonstrated in one of the most promising strains. The environments studied can harbor endospore

  11. WAX ActiveLibrary: a tool to manage information overload.

    Science.gov (United States)

    Hanka, R; O'Brien, C; Heathfield, H; Buchan, I E

    1999-11-01

    WAX Active-Library (Cambridge Centre for Clinical Informatics) is a knowledge management system that seeks to support doctors' decision making through the provision of electronic books containing a wide range of clinical knowledge and locally based information. WAX has been piloted in several regions in the United Kingdom and formally evaluated in 17 GP surgeries based in Cambridgeshire. The evaluation has provided evidence that WAX Active-Library significantly improves GPs' access to relevant information sources and by increasing appropriate patient management and referrals this might also lead to an improvement in clinical outcomes.

  12. An overview of food safety and bacterial foodborne zoonoses in food production animals in the Caribbean region.

    Science.gov (United States)

    Guerra, Maria Manuela Mendes; de Almeida, Andre M; Willingham, Arve Lee

    2016-08-01

    Foodborne diseases (FBDs) in the Caribbean have a high economic burden. Public health and tourism concerns rise along with the increasing number of cases and outbreaks registered over the last 20 years. Salmonella spp., Shigella spp., and Campylobacter spp. are the main bacteria associated with these incidents. In spite of undertaking limited surveillance on FBD in the region, records related to bacterial foodborne zoonoses in food-producing animals and their associated epidemiologic significance are poorly documented, giving rise to concerns about the importance of the livestock, food animal product sectors, and consumption patterns. In this review, we report the available published literature over the last 20 years on selected bacterial foodborne zoonoses in the Caribbean region and also address other food safety-related aspects (e.g., FBD food attribution, importance, surveillance), mainly aiming at recognizing data gaps and identifying possible research approaches in the animal health sector.

  13. Quantitative estimation of net rates of production of bacterial and protozoal nitrogen and their interconversion in the rumen

    International Nuclear Information System (INIS)

    El-Fouly, H.A.

    1983-01-01

    A technique is described using 35 S-labelled bacteria or protozoa by which the rates of production of microbial and protozoal protein N may be calculated. The results indicate an average microbial protein yield of about 13.7gN.d -1 in sheep maintained on a diet consisting largely of cottonseed cake and wheat and rice bran. Evidence is presented that protozoa made little contribution to the microbial protein-N leaving the rumen. Also, the average rate of N flow from the protozoal to the bacterial pool was about 3.5g.d -1 , whereas about 1.4g.d -1 of bacterial N was consumed by protozoa. (author)

  14. Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain

    Science.gov (United States)

    Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Micklem, Chris N.; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S.; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

    2016-01-01

    Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae. Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology. PMID:27247386

  15. Structure and Biosynthesis of Branched Wax Compounds on Wild Type and Wax Biosynthesis Mutants of Arabidopsis thaliana.

    Science.gov (United States)

    Busta, Lucas; Jetter, Reinhard

    2017-06-01

    The cuticle is a waxy composite that protects the aerial organs of land plans from non-stomatal water loss. The chemical make-up of the cuticular wax mixture plays a central role in defining the water barrier, but structure-function relationships have not been established so far, in part due to gaps in our understanding of wax structures and biosynthesis. While wax compounds with saturated, linear hydrocarbon tails have been investigated in detail, very little is known about compounds with modified aliphatic tails, which comprise substantial portions of some plant wax mixtures. This study aimed to investigate the structures, abundances and biosynthesis of branched compounds on the species for which wax biosynthesis is best understood: Arabidopsis thaliana. Microscale derivatization, mass spectral interpretation and organic synthesis identified homologous series of iso-alkanes and iso-alcohols on flowers and leaves, respectively. These comprised approximately 10-15% of wild type wax mixtures. The abundances of both branched wax constituents and accompanying unbranched compounds were reduced on the cer6, cer3 and cer1 mutants but not cer4, indicating that branched compounds are in part synthesized by the same machinery as unbranched compounds. In contrast, the abundances of unbranched, but not branched, wax constituents were reduced on the cer2 and cer26 mutants, suggesting that the pathways to both types of compounds deviate in later steps of chain elongation. Finally, the abundances of branched, but not unbranched, wax compounds were reduced on the cer16 mutant, and the (uncharacterized) CER16 protein may therefore be controlling the relative abundances of iso-alkanes and iso-alcohols on Arabidopsis surfaces. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  16. 21 CFR 155.120 - Canned green beans and canned wax beans.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Canned green beans and canned wax beans. 155.120... Vegetables § 155.120 Canned green beans and canned wax beans. (a) Identity—(1) Definition. Canned green beans and canned wax beans are the foods prepared from succulent pods of fresh green bean or wax bean plants...

  17. Oil-structuring characterization of natural waxes in canola oil oleogels: Rheological, thermal, and oxidative properties

    Science.gov (United States)

    Natural waxes (candelilla wax, carnauba wax, and beeswax) were utilized as canola oil structurants to produce oleogels and their physicochemical properties were evaluated from rheological, thermal, and oxidative points of view. The oleogels with candelilla wax exhibited the highest hardness, followe...

  18. Bacterial Production and Enzymatic Activities in Deep-Sea Sediments of the Pacific Ocean: Biogeochemical Implications of Different Temperature Constraints

    Science.gov (United States)

    Danovaro, R.; Corinaldesi, C.; dell'Anno, A.

    2002-12-01

    The deep-sea bed, acting as the ultimate sink for organic material derived from the upper oceans primary production, is now assumed to play a key role in biogeochemical cycling of organic matter on global scale. Early diagenesis of organic matter in marine sediments is dependent upon biological processes (largely mediated by bacterial activity) and by molecular diffusion. Organic matter reaching the sea floor by sedimentation is subjected to complex biogeochemical transformations that make organic matter largely unsuitable for direct utilization by benthic heterotrophs. Extracellular enzymatic activities in the sediment is generally recognized as the key step in the degradation and utilization of organic polymers by bacteria and a key role in biopolymeric carbon mobilization is played by aminopeptidase, alkaline phosphatase and glucosidase activities. In the present study we investigated bacterial density, bacterial C production and exo-enzymatic activities (aminopeptidase, glucosidase and phosphatase activity) in deep-sea sediments of the Pacific Ocean in relation with the biochemical composition of sediment organic matter (proteins, carbohydrates and lipids), in order to gather information on organic matter cycling and diagenesis. Benthic viral abundance was also measured to investigate the potential role of viruses on microbial loop functioning. Sediment samples were collected at eight stations (depth ranging from 2070-3100 m) along two transects located at the opposite side (north and south) of ocean seismic ridge Juan Fernandez (along latitudes 33° 20' - 33° 40'), constituted by the submerged vulcanoes, which connects the Chilean coasts to Rapa Nui Island. Since the northern and southern sides of this ridge apparently displayed small but significant differences in deep-sea temperature (related to the general ocean circulation), this sampling strategy allowed also investigating the role of different temperature constraints on bacterial activity and

  19. Biochemical characterization and substrate specificity of jojoba fatty acyl-CoA reductase and jojoba wax synthase.

    Science.gov (United States)

    Miklaszewska, Magdalena; Banaś, Antoni

    2016-08-01

    Wax esters are used in industry for production of lubricants, pharmaceuticals and cosmetics. The only natural source of wax esters is jojoba oil. A much wider variety of industrial wax esters-containing oils can be generated through genetic engineering. Biotechnological production of tailor-made wax esters requires, however, a detailed substrate specificity of fatty acyl-CoA reductases (FAR) and wax synthases (WS), the two enzymes involved in wax esters synthesis. In this study we have successfully characterized the substrate specificity of jojoba FAR and jojoba WS. The genes encoding both enzymes were expressed heterologously in Saccharomyces cerevisiae and the activity of tested enzymes was confirmed by in vivo studies and in vitro assays using microsomal preparations from transgenic yeast. Jojoba FAR exhibited the highest in vitro activity toward 18:0-CoA followed by 20:1-CoA and 22:1-CoA. The activity toward other 11 tested acyl-CoAs was low or undetectable as with 18:2-CoA and 18:3-CoA. In assays characterizing jojoba WS combinations of 17 fatty alcohols with 14 acyl-CoAs were tested. The enzyme displayed the highest activity toward 14:0-CoA and 16:0-CoA in combination with C16-C20 alcohols as well as toward C18 acyl-CoAs in combination with C12-C16 alcohols. 20:1-CoA was efficiently utilized in combination with most of the tested alcohols. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Designing maleic anhydride-{alpha}-olifin copolymeric combs as wax crystal growth nucleators

    Energy Technology Data Exchange (ETDEWEB)

    Soni, Hemant P. [Department of Chemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara-390 002 (India); Kiranbala; Bharambe, D.P. [Department of Applied Chemistry, Faculty of Technology and Engineering, The Maharaja Sayajirao University of Baroda, Vadodara-390 001 (India); Agrawal, K.S. [Department of Petrochemical Technology, Polytechnic, The Maharaja Sayajirao University of Baroda, Vadodara-390 002 (India); Nagar, A. [MH ASSET, ONGC, Mumbai (India)

    2010-09-15

    Modification of the wax crystal habit is of great practical interest during transportation and processing of crude oil at low temperature. Various pour point depressant (PPD) additives can facilitate this modification by different mechanisms. Comb shaped polymer additives are known to depress the pour point of crude oil by providing different nucleation sites for the precipitation of wax. This paper describes performance based design, synthesis, characterization and evaluation of comb shaped polymeric diesters. Copolymers of maleic anhydride with different unsaturated C{sub 22} esters were synthesized and copolymers then reacted with two unsaturated fatty alcohols. All products were characterized by Fourier Transform Infra Red (FTIR) spectroscopy and Gel Permeation Chromatography (GPC). Rheological properties of crude (with and without additive) were studied by Advance Rheometer AR-500. In this study the additive based on oleic acid was evaluated as good PPD and rheology modifier. (author)

  1. Evaluation of Physical Properties of Wax Mixtures Obtained From Recycling of Patterns Used in Precision Casting

    Directory of Open Access Journals (Sweden)

    Biernacki R.

    2015-04-01

    Full Text Available The study investigated the properties of selected certified mixtures used to make wax patterns for the production of precision castings for the aerospace industry. In addition, an assessment of the recycled mixtures consisting of certified wax materials recovered during autoclaving was carried out. Hardness was tested via a proposed method based on penetration, creep related deformation, bending strength and linear contraction. The hardness was studied on laboratory specimens and patterns made with the use of injection molding equipment. For these patterns, linear contraction was estimated at variable pressure and for different temperature injection parameters. Deformations connected with creep and resistance were evaluated on cylindrical specimens. Differences in creep resistance in relation to the hardness were observed depending on the type of pattern mixtures. Recycled mixture has a greater resistance and smaller linear contraction than certified mixtures used for making sprue, raisers and other parts of filler system.

  2. The Effect of Chrysonilia crassa Additive on Duodenal & Caecal Morphology, Bacterial & Fungal Number, and Productivity of Ayam Kampung

    Directory of Open Access Journals (Sweden)

    Turrini Yudiarti

    2012-10-01

    Full Text Available Fungi is a microorganism that can live in gastrointestinal tract of chicken. One type of fungi is multicellular or filamentous fungi. C.crassa is a species of filamentous fungi that has been isolated in the earlier study and it showed the best probiotic potency in vitro. The obyective of this research was to study the effect of addition of dried culture of  C.crassa in feed on intestinal & caecal morphology, bacterial & fungal number, and  productivity of indigenous chicken (ayam kampung. Research used completely randomized design with four treatments. The treatments were the level of  dried culture in basal diet (0%, 0.25 %,  0.50 % and 0.75 %. Each treatment was replicated 5 times and each replicate consists of 10 chickens. The parameters observed were : villi morphology, number of bacteria and fungi in the duodenum and cecum of chickens aged 1, 21 and 35 days and productivity i.e. feed intake, final body weight and feed conversion. The results showed that 0.50% dried culture of C.crassa could increase the duodenal villi width, decreased the number of bacterial and fungal colonies in duodenum and caecum, but it did not increase productivity. The conclusion : C.crassa could stimulate the duodenal villi development and decreased the number of the bacteria and fungi in the gastrointestinal tract, yet it has no positive impact on the chicken productivity.

  3. The Effect of Chrysonilia crassa Additive on Duodenal & Caecal Morphology, Bacterial & Fungal Number, and Productivity of Ayam Kampung

    Directory of Open Access Journals (Sweden)

    T. Yudiarti

    2012-10-01

    Full Text Available Fungi is a microorganism that can live in gastrointestinal tract of chicken. One type of fungi is multicellular or filamentous fungi. C.crassa is a species of filamentous fungi that has been isolated in the earlier study and it showed the best probiotic potency in vitro. The obyective of this research was to study the effect of addition of dried culture of C.crassa in feed on intestinal & caecal morphology, bacterial & fungal number, and productivity of indigenous chicken (ayam kampung. Research used completely randomized design with four treatments. The treatments were the level of dried culture in basal diet (0%, 0.25 %, 0.50 % and 0.75 %. Each treatment was replicated 5 times and each replicate consists of 10 chickens. The parameters observed were : villi morphology, number of bacteria and fungi in the duodenum and cecum of chickens aged 1, 21 and 35 days and productivity i.e. feed intake, final body weight and feed conversion. The results showed that 0.50% dried culture of C.crassa could increase the duodenal villi width, decreased the number of bacterial and fungal colonies in duodenum and caecum, but it did not increase productivity. The conclusion : C.crassa could stimulate the duodenal villi development and decreased the number of the bacteria and fungi in the gastrointestinal tract, yet it has no positive impact on the chicken productivity

  4. Reproduction and subchronic feeding study of carnauba wax in rats.

    Science.gov (United States)

    Parent, R A; Re, T A; Babish, J G; Cox, G E; Voss, K A; Becci, P J

    1983-02-01

    The reproductive performance of Wistar rats fed carnauba wax at levels of 0.1, 0.3 or 1% in the diet and the effects of subchronic administration of carnauba wax at these dose levels on the resultant progeny were studied. Reproductive indices, body-weight gain, food consumption, haematological and clinical chemical data, ophthalmic, gross and histopathological examinations were used to study the possible toxic or pathological effects. Serum free fatty acid levels were found to be decreased in male and female rats fed carnauba wax at dietary levels of 0.3 and 1.0%. No other effects of feeding carnauba wax at levels up to 1.0% of the diet were observed.

  5. The effects of magnetic fields on carnauba wax electret formation

    Science.gov (United States)

    Clator, Irvin G.

    1987-08-01

    The results of thermally stimulated depolarization current and effective surface charge-density measurements indicate that magnetic fields do not produce carnauba wax electrets and that previously reported data can be attributed to nonmagnetic effects.

  6. Characterization and chemical composition of epicuticular wax from banana leaves grown in Northern Thailand

    Directory of Open Access Journals (Sweden)

    Suporn Charumanee

    2017-08-01

    Full Text Available This study aimed to investigate the physicochemical properties and chemical composition of epicuticular wax extracted from leaves of Kluai Namwa, a banana cultivar which is widely grown in Northern Thailand. Its genotype was identified by a botanist. The wax was extracted using solvent extraction. The fatty acid profiles and physicochemical properties of the wax namely melting point, congealing point, crystal structures and polymorphism, hardness, color, and solubility were examined and compared to those of beeswax, carnauba wax and paraffin wax. The results showed that the genotype of Kluai Namwa was Musa acuminata X M. balbisiana (ABB group cv. Pisang Awak. The highest amount of wax extracted was 274 μg/cm2 surface area. The fatty acid composition and the physicochemical properties of the wax were similar to those of carnauba wax. It could be suggested that the banana wax could be used as a replacement for carnauba wax in various utilizing areas.

  7. Bacterial production of site specific {sup 13}C labeled phenylalanine and methodology for high level incorporation into bacterially expressed recombinant proteins

    Energy Technology Data Exchange (ETDEWEB)

    Ramaraju, Bhargavi; McFeeters, Hana; Vogler, Bernhard; McFeeters, Robert L., E-mail: robert.mcfeeters@uah.edu [University of Alabama in Huntsville, Department of Chemistry (United States)

    2017-01-15

    Nuclear magnetic resonance spectroscopy studies of ever larger systems have benefited from many different forms of isotope labeling, in particular, site specific isotopic labeling. Site specific {sup 13}C labeling of methyl groups has become an established means of probing systems not amenable to traditional methodology. However useful, methyl reporter sites can be limited in number and/or location. Therefore, new complementary site specific isotope labeling strategies are valuable. Aromatic amino acids make excellent probes since they are often found at important interaction interfaces and play significant structural roles. Aromatic side chains have many of the same advantages as methyl containing amino acids including distinct {sup 13}C chemical shifts and multiple magnetically equivalent {sup 1}H positions. Herein we report economical bacterial production and one-step purification of phenylalanine with {sup 13}C incorporation at the Cα, Cγ and Cε positions, resulting in two isolated {sup 1}H-{sup 13}C spin systems. We also present methodology to maximize incorporation of phenylalanine into recombinantly overexpressed proteins in bacteria and demonstrate compatibility with ILV-methyl labeling. Inexpensive, site specific isotope labeled phenylalanine adds another dimension to biomolecular NMR, opening new avenues of study.

  8. Mineral and tar oils and paraffin and mineral waxes, extracting

    Energy Technology Data Exchange (ETDEWEB)

    1927-09-01

    In the extraction of soluble bodies from coal and the like carbonaceous material, the coal is preheated in a closed vessel and then heated under pressure with the solvent. The pressure in either or both stages may be increased by gases or vapours more or less inert under the conditions, e.g. hydrogen, steam, carbon monoxide, and nitrogen. In an example, brown coal is maintained at 300/sup 0/C for 10 hours, thus producing a pressure of 100 atmospheres, and is then extracted for 10 hours at 300/sup 0/C and 100 atmospheres with benzene in a closed vessel. Over 60 per cent of the coal is dissolved. After separation of the undissolved coal and removal of the solvent the soluble products may be treated with either to extract resinous matter, and then with cyclohexane to extract wax-like matters. Alternatively the soluble products, alone or in solution or with the undissolved coal, may be destructively hydrogenated, or be cracked in presence of activated aluminium and hydrogen chloride.

  9. CARNAUBA WAX USED AS AN HYDROPHOBIC AGENT FOR EXPANDED VERMICULITE

    Directory of Open Access Journals (Sweden)

    M.A.F. Melo

    1998-03-01

    Full Text Available This work deals with the use of carnauba wax as an expansion and hydrophobicity agent for vermiculite, to be utilized in the sorption process of oil in water. Evaluation of the system (oil-water-hydrophobic vermiculite submersion percentage was considered in assessing the performance of vermiculite in comparison to a Mexican turf. Carnauba wax seems to be more efficient in both fresh and salt waters.

  10. Subchronic feeding study of carnauba wax in beagle dogs.

    Science.gov (United States)

    Parent, R A; Cox, G E; Babish, J G; Gallo, M A; Hess, F G; Becci, P J

    1983-02-01

    Carnauba wax fed at levels of 0.1, 0.3 and 1% in the diet to beagle dogs for 28 wk did not produce evidence of toxicity or pathological effects. Body weight gain, food consumption, clinical chemical, haematological, and urine analysis data, and organ weights of animals fed carnauba wax were comparable with those of control animals. Ophthalmic, gross and histopathological examinations revealed no significant treatment-related findings.

  11. Sintering of wax for controlling release from pellets

    OpenAIRE

    Singh, Reena; Poddar, S. S.; Chivate, Amit

    2007-01-01

    The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%–20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusio...

  12. Effects of UV-B radiation on wax biosynthesis

    International Nuclear Information System (INIS)

    Barnes, J.; Paul, N.; Percy, K.; Broadbent, P.; McLaughlin, C.; Mullineaux, P.; Creissen, G.; Wellburn, A.

    1994-01-01

    Two genotypes of tobacco (Nicotiana tabacum L.) were exposed in controlled environment chambers to three levels of biologically effective ultraviolet-B radiation (UV-B BE ; 280-320nm): 0, 4.54 (ambient) and 5.66 (∼ 25% enhancement) kJ m -2 d -1 . After 28 days, the quantity of wax deposited on leaf surfaces was determined gravimetrically; epicuticular wax chemical composition was determined by capillary gas chromatography with homologue assignments confirmed by gas chromatography-mass spectrometry. Leaf wettability was assessed by measuring the contact angle of water droplets placed on leaf surfaces. Tobacco wax consisted of three major hydrocarbon classes: Straight-chain alkanes (C 27 -C 33 ) which comprised ∼ 59% of the hydrocarbon fraction, containing a predominance of odd-chain alkanes with C 31 as the most abundant homologue; branched-chain alkanes (C 25 -C 32 ) which comprised ∼38% of the hydrocarbon fraction with anteiso 3-methyltriacontane (C 30 ) as the predominant homologue; and fatty acids (C 14 -C 18 ) which comprised ∼ 3% of the wax. Exposure to enhanced UV-B radiation reduced the quantity of wax on the adaxial surface of the transgenic mutant, and resulted in marked changes in the chemical composition of the wax on the exposed leaf surface. Enhanced UV-B decreased the quantity of straight-chain alkanes, increased the quantity of branched-chain alkanes and fatty acids, and resulted in shifts toward shorter straight-chain lengths. Furthermore, UV-B-induced changes in wax composition were associated with increased wettability of tobacco leaf surfaces. Overall, the data are consistent with the view that UV-B radiation has a direct and fundamental effect on wax biosynthesis. Relationships between the physico-chemical nature of the leaf surface and sensitivity to UV-B radiation are discussed. (orig.)

  13. Lower Carboniferous Siderites: A Product of Bottom Seeps and Bacterial Metanogenesis (Subpolar Urals)

    Science.gov (United States)

    Antoshkina, A. I.; Ryabinkina, N. N.

    2018-02-01

    Complex modern micro- and spectroscopic methods for study of siderite concretions in the Lower Carboniferous terrigenous strata on the Kozhym River (Subpolar Urals) have shown that its formation was caused by destruction of clay minerals due to the activity of bacterial communities. The abundance of these bacteria was caused by gas-fluid seeps and bacterial methanogenesis processes in bottom deposits. In basins with normal marine fauna, this led to local desalination, hydrogen sulfide contamination, mass collapse of primary organisms, and the development of element-specific bacteria. The occurrence of these bacteria caused the formation of specific authigenic mineralization in the concretion of sideritic bacteriolites: the framboidal pyrite, sphalerite, galenite, barite, sulfoselenides, and tellurides.

  14. Aryl Polyenes, a Highly Abundant Class of Bacterial Natural Products, Are Functionally Related to Antioxidative Carotenoids.

    Science.gov (United States)

    Schöner, Tim A; Gassel, Sören; Osawa, Ayako; Tobias, Nicholas J; Okuno, Yukari; Sakakibara, Yui; Shindo, Kazutoshi; Sandmann, Gerhard; Bode, Helge B

    2016-02-02

    Bacterial pigments of the aryl polyene type are structurally similar to the well-known carotenoids with respect to their polyene systems. Their biosynthetic gene cluster is widespread in taxonomically distant bacteria, and four classes of such pigments have been found. Here we report the structure elucidation of the aryl polyene/dialkylresorcinol hybrid pigments of Variovorax paradoxus B4 by HPLC-UV-MS, MALDI-MS and NMR. Furthermore, we show for the first time that this pigment class protects the bacterium from reactive oxygen species, similarly to what is known for carotenoids. An analysis of the distribution of biosynthetic genes for aryl polyenes and carotenoids in bacterial genomes is presented; it shows a complementary distribution of these protective pigments in bacteria. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Culture-independent bacterial community analysis of the salty-fermented fish paste products of Thailand and Laos

    Science.gov (United States)

    MARUI, Junichiro; BOULOM, Sayvisene; PANTHAVEE, Wanchai; MOMMA, Mari; KUSUMOTO, Ken-Ichi; NAKAHARA, Kazuhiko; SAITO, Masayoshi

    2015-01-01

    A bacterial community analysis, using a culture-independent method (polymerase chain reaction-denaturing gradient gel electrophoresis), detected 17 species of bacteria including species of the genera Tetragenococcus, Lactobacillus, Pediococcus, Weissella Halanaerobium, Clostridium, and Sphingomonas in a traditional salty-fermented fish paste known as pla-ra or pa-daek in Thailand and Laos, which is used as a storage-stable multi-purpose seasoning. The representative genus of lactic acid bacteria seemed to vary in the 10 products collected from Thailand and Laos. Tetragenococci were common in products from central Thailand and Vientiane in Laos which had salinities of not less than 11% and pH values ranging from 5.6 to 6.1. However, lactobacilli were common in products from northern Thailand which had the lowest salinities (8.3–8.6%) and pH values (4.5–4.8) of all the samples examined. Two Lactobacillus and one Tetragenococcus species were detected in one product from northeastern Thailand containing 10% salt. These results suggest that salinity in pla-ra/pa-daek is an important determinant of the representative genus of lactic acid bacteria such as, Tetragenococcus or Lactobacillus. Additionally, differences in the acidity between these two groups seemed to be related to the production of d-/l-lactic acid in the lactic acid bacteria in each product. This is the first study to report a correlation between bacterial community structure and taste components in pla-ra/pa-daek products from various regions. This scientific work on a traditional fermented food will be useful in helping local producers meet differing consumer preferences in various regions. PMID:25918672

  16. Surface-Selective Preferential Production of Reactive Oxygen Species on Piezoelectric Ceramics for Bacterial Killing

    OpenAIRE

    Tan, Guoxin; Wang, Shuangying; Zhu, Ye; Zhou, Lei; Yu, Peng; Wang, Xiaolan; He, Tianrui; Chen, Junqi; Mao, Chuanbin; Ning, Chengyun

    2016-01-01

    Reactive oxygen species (ROS) can be used to kill bacterial cells, and thus the selective generation of ROS from material surfaces is an emerging direction in antibacterial material discovery. We found the polarization of piezoelectric ceramic causes the two sides of the disk to become positively and negatively charged, which translate into cathode and anode surfaces in an aqueous solution. Because of the microelectrolysis of water, ROS are preferentially formed on the cathode surface. Conseq...

  17. Nest wax triggers worker reproduction in the bumblebee Bombus terrestris.

    Science.gov (United States)

    Rottler-Hoermann, Ann-Marie; Schulz, Stefan; Ayasse, Manfred

    2016-01-01

    Social insects are well known for their high level of cooperation. Workers of the primitively eusocial bumblebee Bombus terrestris are able to produce male offspring in the presence of a queen. Nonetheless, they only compete for reproduction, in the so-called competition phase, when the workforce is large enough to support the rearing of reproductives. So far, little is known about the proximate mechanisms underlying the shift between altruism and selfish behaviour in bumblebee workers. In this study, we have examined the influence of chemical cues from the nest wax on the onset of worker reproduction. Chemical analyses of wax extracts have revealed that the patterns and amounts of cuticular lipids change considerably during colony development. These changes in wax scent mirror worker abundance and the presence of fertile workers. In bioassays with queen-right worker groups, wax affects the dominance behaviour and ovarian development of workers. When exposed to wax from a colony in competition phase, workers start to compete for reproduction. We suggest that wax scent enables workers to time their reproduction by providing essential information concerning the social condition of the colony.

  18. Production of putrescine-capped stable silver nanoparticle: its characterization and antibacterial activity against multidrug-resistant bacterial strains

    Science.gov (United States)

    Saha, Saswati; Gupta, Bhaskar; Gupta, Kamala; Chaudhuri, Mahua Ghosh

    2016-11-01

    Integration of biology with nanotechnology is now becoming attention-grabbing area of research. The antimicrobial potency of silver has been eminent from antiquity. Due to the recent desire for the enhancement of antibacterial efficacy of silver, various synthesis methods of silver in their nano dimensions are being practiced using a range of capping material. The present work highlights a facile biomimetic approach for production of silver nanoparticle being capped and stabilized by putrescine, possessing a diameter of 10-25 ± 1.5 nm. The synthesized nanoparticles have been analyzed spectrally and analytically. Morphological studies are carried out by high-resolution transmission electron microscopy and crystallinity by selected area electron diffraction patterns. Moreover, the elemental composition of the capped nanoparticles was confirmed by energy-dispersive X-ray spectroscopy analysis. A comparative study (zone of inhibition and minimum inhibitory concentration) regarding the interactions and antibacterial potentiality of the capped silver nanoparticles with respect to the bare ones reveal the efficiency of the capped one over the bare one. The bacterial kinetic study was executed to monitor the interference of nanoparticles with bacterial growth rate. The results also highlight the efficacy of putrescine-capped silver nanoparticles as effective growth inhibitors against multi-drug resistant human pathogenic bacterial strains, which may, thus, potentially be applicable as an effective antibacterial control system to fight diseases.

  19. Characterization of corrosive bacterial consortia isolated from petroleum-product-transporting pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Rajasekar, Aruliah; Ting, Yen-Peng [National Univ. of Singapore (Singapore). Dept. of Chemical and Biomolecular Engineering; Anandkumar, Balakrishnan [Sourashtra Coll., Madurai (India). Dept. of Biotechnology; Maruthamuthu, Sundaram [Central Electrochemical Research Inst., Karaikudi (India). Biocorrosion Group; Rahman, Pattanathu K.S.M. [Teesside Univ., Tees Valley (United Kingdom). Chemical and Bioprocess Engineering Group

    2010-01-15

    Microbiologically influenced corrosion is a problem commonly encountered in facilities in the oil and gas industries. The present study describes bacterial enumeration and identification in diesel and naphtha pipelines located in the northwest and southwest region in India, using traditional cultivation technique and 16S rDNA gene sequencing. Phylogenetic analysis of 16S rRNA sequences of the isolates was carried out, and the samples obtained from the diesel and naphtha-transporting pipelines showed the occurrence of 11 bacterial species namely Serratia marcescens ACE2, Bacillus subtilis AR12, Bacillus cereus ACE4, Pseudomonas aeruginosa AI1, Klebsiella oxytoca ACP, Pseudomonas stutzeri AP2, Bacillus litoralis AN1, Bacillus sp., Bacillus pumilus AR2, Bacillus carboniphilus AR3, and Bacillus megaterium AR4. Sulfate-reducing bacteria were not detected in samples from both pipelines. The dominant bacterial species identified in the petroleum pipeline samples were B. cereus and S. marcescens in the diesel and naphtha pipelines, respectively. Therefore, several types of bacteria may be involved in biocorrosion arising from natural biofilms that develop in industrial facilities. In addition, localized (pitting) corrosion of the pipeline steel in the presence of the consortia was observed by scanning electron microscopy analysis. The potential role of each species in biofilm formation and steel corrosion is discussed. (orig.)

  20. Evaluation of effectiveness of bacterial product which can degrade pesticide-dimethoate on the scale of true practice test

    International Nuclear Information System (INIS)

    Pham Thi Le Ha; Tran Thi Thuy; Le Hai; Nguyen Duy Hang; Vo Thi Thu Ha; Nguyen Tuong Ly Lan; Le Tat Mua; Tran Kim Duyen; Mai Hoang Lam

    2004-01-01

    Dimethoate, an organophosphate pesticide has been widely used in Dalat, Lamdong. It is much toxic to birds, human being and other mammals. Its widespread use has caused environmental concern on the basic of frequent detection of dimethoate in soil and water. Microorganisms are key agents in the degradation of waste, oil and a vast array of organic pesticide in terrestrial and aquatic ecosystems. In previous study, bacteria products which can degrade. Dimethoate were produced. The present study was designed to evaluate the effectiveness of bacterial product which can degrade Pesticide-Dimethoate on the scale of true practice test. The results indicated that application bacteria product to soil grown with Cauliflower and Chinese Cabbage sprayed with organic phosphorus pesticides (Dimethoate and Chloropyrifos), the pesticide residues in soil, water and vegetables were as follow: The residues of Dimethoate and Chloropyrifos in soil grown with Cauliflower, Chinese cabbages are different. They concentrated mostly in the surface litter and top soil layers with the depth from 0 to 20 cm. From the depth of 20 cm to 100 cm, the pesticide residues were ignorable. Residue of Chloropyrifos in soil was small as well. Dimethoate residues in soil grown with Cauliflower were higher than that of Chinese cabbages. On the basis of the environmental criteria of Ministry for Science, Technology and Environment (6/95), Dimethoate residues in soil grown with cauliflowers were in excess of the maximum limit. In the case of using bacteria product to soil, pesticide residues in soil were decreased. The results also indicated that Chloropyrifos residues in water (water obtained at the depth of 75 cm and 100 cm by days) were small. Residue of Dimethoate in water small. Residue of Dimethoate in water obtained from the Cauliflower bed were higher than of Chinese cabbages one. Using bacteria product to soil, pesticide residues in water decreased. On the basis of the environmental criteria of

  1. Heterotrophic bacterial production, respiration, and growth efficiency associated with upwelling intensity in the Ulleung Basin, East Sea

    Science.gov (United States)

    Kim, Bomina; Kim, Sung-Han; Kwak, Jung Hyun; Kang, Chang-Keun; Lee, Sang Heon; Hyun, Jung-Ho

    2017-09-01

    We investigated bacterial production (BP) and respiration (BR), as well as the physico-chemical properties of the water column, to elucidate the effect of upwelling on heterotrophic bacterial metabolic activities and growth efficiency (BGE) in July 2012 and May 2013 in the Ulleung Basin (UB), East/Japan Sea. The upwelled conditions were characterized by higher chlorophyll-a (Chl-a) concentrations resulting from the upward shift of the nitracline compared to that of the non-upwelled condition. Analyses of the size fractions of Chl-a and pigment composition revealed that large size phytoplankton (> 20 μm), mainly consisting of diatoms, appeared to be the major phytoplankton component. BP and BR were significantly correlated with Chl-a (P 0.05). These results suggest that bacterial metabolic activities are stimulated by the availability of organic resources enhanced by upwelling in the UB. Further statistical analysis showed that the difference in BP and BGE with variations in upwelling intensity were significant (P = 0.018 for BP, P = 0.035 for BGE), but the difference in BR was not significant (P = 0.321). These results suggest that metabolic energy is partitioned more for BP under a strong upwelling condition, i.e. high nutrient and Chl-a conditions. In contrast, the energy generated via respiration was partitioned more for maintaining metabolism rather than for biomass production under weakly or non-upwelled conditions, i.e. stratified and low Chl-a conditions. Overall, our results suggest that any changes in upwelling intensity would significantly affect the carbon cycle associated with the fate of primary production, and the role of the microbial loop in the UB where changes in the intensity and frequency of upwelling associated with climatic changes are in progress.

  2. Seasonal dynamics of bacterial biomass and production in a coastal arctic ecosystem: Franklin Bay, western Canadian Arctic

    Science.gov (United States)

    Garneau, Marie-Ã. Ve; Roy, SéBastien; Lovejoy, Connie; Gratton, Yves; Vincent, Warwick F.

    2008-07-01

    The Canadian Arctic Shelf Exchange Study (CASES) included the overwintering deployment of a research platform in Franklin Bay (70°N, 126°W) and provided a unique seasonal record of bacterial dynamics in a coastal region of the Arctic Ocean. Our objectives were (1) to relate seasonal bacterial abundance (BA) and production (BP) to physico-chemical characteristics and (2) to quantify the annual bacterial carbon flux. BA was estimated by epifluorescence microscopy and BP was estimated from 3H-leucine and 3H-thymidine assays. Mean BA values for the water column ranged from 1.0 (December) to 6.8 × 105 cells mL-1 (July). Integral BP varied from 1 (February) to 80 mg C m-2 d-1 (July). During winter-spring, BP was uncorrelated with chlorophyll a (Chl a), but these variables were significantly correlated during summer-autumn (rs = 0.68, p winter, late winter-late spring, and summer. A baseline level of BB and BP was maintained throughout late winter-late spring despite the persistent cold and darkness, with irregular fluctuations that may be related to hydrodynamic events. During this period, BP rates were correlated with colored dissolved organic matter (CDOM) but not Chl a (rs BP.CDOM∣Chl a = 0.20, p < 0.05, N = 176). Annual BP was estimated as 6 g C m-2 a-1, implying a total BP of 4.8 × 1010 g C a-1 for the Franklin Bay region. These results show that bacterial processes continue throughout all seasons and make a large contribution to the total biological carbon flux in this coastal arctic ecosystem.

  3. The Effect of Chrysonilia crassa Additive on Duodenal & Caecal Morphology, Bacterial & Fungal Number, and Productivity of Ayam Kampung

    OpenAIRE

    Turrini Yudiarti; V. D. Yunianto B.I; R. Murwani; E. Kusdiyantini

    2012-01-01

    Fungi is a microorganism that can live in gastrointestinal tract of chicken. One type of fungi is multicellular or filamentous fungi. C.crassa is a species of filamentous fungi that has been isolated in the earlier study and it showed the best probiotic potency in vitro. The obyective of this research was to study the effect of addition of dried culture of  C.crassa in feed on intestinal & caecal morphology, bacterial & fungal number, and  productivity of indigenous chicken (ayam kamp...

  4. Modifications in bacterial groups and short chain fatty acid production in the gut of healthy adult rats after long-term consumption of dietary Maillard reaction products.

    Science.gov (United States)

    Delgado-Andrade, Cristina; Pastoriza de la Cueva, Silvia; Peinado, M Jesús; Rufián-Henares, José Ángel; Navarro, M Pilar; Rubio, Luis A

    2017-10-01

    Bread crust (BC) is one of the major sources of Maillard reaction products (MRPs) in the Western diet. This work was designed to analyze the impact of diets containing important levels of MRPs from BC on intestinal bacterial growth and short chain fatty acids (SCFAs) production in adult rats. Additionally, the pools of compounds excreted in feces attending to their molecular weights were analyzed. Rats were fed for 88days a control diet or diets containing BC or its soluble high molecular weight (HMW), soluble low molecular weight (LMW) or insoluble fractions, respectively. Intestinal (cecum) microbiota composition was determined by qPCR analysis. Consumption of the BC diet lowered (PMaillard reaction products are in vivo fermented by the gut microbiota, thereby changing both the pattern of SCFAs production and the microbiota composition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Manipulating the glycosylation pathway in bacterial and lower eukaryotes for production of therapeutic proteins

    DEFF Research Database (Denmark)

    Anyaogu, Diana Chinyere; Mortensen, Uffe Hasbro

    2015-01-01

    The medical use of pharmaceutical proteins is rapidly increasing and cheap, fast and efficient production is therefore attractive. Microbial production hosts are promising candidates for development and production of pharmaceutical proteins. However, as most therapeutic proteins are secreted...... to produce proteins with humanlike glycan structures setting the stage for production of pharmaceutical proteins in bacteria, yeasts and algae....

  6. Monitoring agrochemical diffusion through cuticle wax with coherent Raman scattering

    Science.gov (United States)

    Gaunt, Nicholas P.; Thomson, Niall; Padia, Faheem; Moger, Julian

    2018-02-01

    The world's population is increasing rapidly and higher calorific diets are becoming more common; as a consequence the demand for grain is predicted to increase by more than 50% by 2050 without a significant increase in the available agricultural land. Maximising the productivity of the existing agricultural land is key to maintaining food security and agrochemicals continue to be a key enabler for the efficiency gains required. However, agrochemicals can be susceptible to significant losses and thus often require further chemical to be applied to compensate. Sources of such losses include spray drift, poor spray retention/capture by the target and poor penetration through the plant cuticle. Adjuvants can be used to help mitigate such losses but characterising how they alter the movement of the active ingredients (AIs) can be challenging. In this contribution we demonstrate the use of coherent Raman Scattering (CRS) as a tool to enable in-situ, real-time, label free characterisation of agrochemical AI as they move through wax.

  7. Surface-Selective Preferential Production of Reactive Oxygen Species on Piezoelectric Ceramics for Bacterial Killing.

    Science.gov (United States)

    Tan, Guoxin; Wang, Shuangying; Zhu, Ye; Zhou, Lei; Yu, Peng; Wang, Xiaolan; He, Tianrui; Chen, Junqi; Mao, Chuanbin; Ning, Chengyun

    2016-09-21

    Reactive oxygen species (ROS) can be used to kill bacterial cells, and thus the selective generation of ROS from material surfaces is an emerging direction in antibacterial material discovery. We found the polarization of piezoelectric ceramic causes the two sides of the disk to become positively and negatively charged, which translate into cathode and anode surfaces in an aqueous solution. Because of the microelectrolysis of water, ROS are preferentially formed on the cathode surface. Consequently, the bacteria are selectively killed on the cathode surface. However, the cell experiment suggested that the level of ROS is safe for normal mammalian cells.

  8. Development of Wax-Incorporated Emulsion Gel Beads for the Encapsulation and Intragastric Floating Delivery of the Active Antioxidant from Tamarindus indica L.

    Directory of Open Access Journals (Sweden)

    Sitthiphong Soradech

    2016-03-01

    Full Text Available In this study, tamarind (Tamarindus indica L. seed extracts with potential antioxidant activity and toxicity to cancer cells were developed as functional foods and nutraceutical ingredients in the form of emulsion gel beads. Three extracts were obtained from ethanol and water: TSCH50, TSCH95 and TSCH. All extracts exhibited high potential for superoxide anion scavenging activity over the IC50 range < 5–11 µg/mL and had no toxic effects on normal cells, however, the water extract (TSCH was the most effective due to its free radical scavenging activity and toxicity in mitochondrial membranes of cancer cells. Next a study was designed to develop a new formulation for encapsulation and intragastric floating delivery of tamarind seed extract (TSCH using wax-incorporated emulsion gel beads, which were prepared using a modified ionotropic gelation technique. Tamarind seed extract at 1% (w/w was used as the active ingredient in all formulations. The effect of the types and amounts of wax on the encapsulation efficiency and percentage of the active release of alginate gel beads was also investigated. The results demonstrated that the incorporation of both waxes into the gel beads had an effect on the percentage of encapsulation efficiency (% and the percentage of the active ingredient release. Furthermore, the addition of water insoluble waxes (carnauba and bee wax significantly retarded the release of the active ingredient. The addition of both waxes had a slight effect on drug release behavior. Nevertheless, the increase in incorporated waxes in all formulations could sustain the percentage of active ingredient release. In conclusion, wax-incorporated emulsion gel beads using a modified ionotropic gelation technique could be applied for the intragastric floating delivery and controlled release of functional food and nutraceutical products for their antioxidant and anticancer capacity.

  9. Investigation of liquid wax components of Egyptian jojoba seeds.

    Science.gov (United States)

    El-Mallah, Mohammed Hassan; El-Shami, Safinaz Mohammed

    2009-01-01

    Egyptian jojoba seeds newly cultivated in Ismailia desert in Egypt promoted us to determine its lipid components. Fatty alcohols, fatty acids, wax esters and sterols patterns were determined by capillary GLC whereas, tocopherols profile, isopropenoid alcohols and sterylglycosides were determined by HPLC. The Egyptian seeds are rich in wax esters (55 %) with fatty alcohols C20:1 and C22:1 as major components and amounted to 43.0 % and 45.6 % respectively followed by C24:1 and C18:1(9.6 % and 1.3 % respectively). The fatty acids profile showed that C20:1 is the major constituent (60 %) followed by C18:1 and C22:1 (14.5 and 11.8 % respectively) whereas C24:1 was present at low concentration amounted to 1.6 %. In addition, the Egyptian jojoba wax contained C18:2 fatty acid at a level of 8.7 %. Wax esters composition showed that the local wax had C42 and C40 esters as major components amounted to 51.1 and 30.1 % respectively. Also, it had C44 and C38 at reasonable amounts (10.0 and 6.3 % respectively). Whereas C36 and C46 were present at lower concentrations amounted to 1.4 and 1.1 respectively. The sterols analysis showed the presence of campe-, stigma-, beta-sito-, and isofuco- sterol amounting to 18.4 %, 6.9 %, 68.7 %, and 6.0 % respectively. The tocopherols pattern revealed that the local seed wax contained gamma-tocopherol as major constituent (79.2 %) followed by alpha-tocopherol (20.3 %). beta-tocopherol as well as delta-tocopherol were found as minor constituents. The isopropenoid alcohols and the sterylglycosides (free and acylated) were not detected. The wax is proposed to be used in oleo chemistry and cosmetics.

  10. Multi-parameter flow cytometry as a process analytical technology (PAT) approach for the assessment of bacterial ghost production.

    Science.gov (United States)

    Langemann, Timo; Mayr, Ulrike Beate; Meitz, Andrea; Lubitz, Werner; Herwig, Christoph

    2016-01-01

    Flow cytometry (FCM) is a tool for the analysis of single-cell properties in a cell suspension. In this contribution, we present an improved FCM method for the assessment of E-lysis in Enterobacteriaceae. The result of the E-lysis process is empty bacterial envelopes-called bacterial ghosts (BGs)-that constitute potential products in the pharmaceutical field. BGs have reduced light scattering properties when compared with intact cells. In combination with viability information obtained from staining samples with the membrane potential-sensitive fluorescent dye bis-(1,3-dibutylarbituric acid) trimethine oxonol (DiBAC4(3)), the presented method allows to differentiate between populations of viable cells, dead cells, and BGs. Using a second fluorescent dye RH414 as a membrane marker, non-cellular background was excluded from the data which greatly improved the quality of the results. Using true volumetric absolute counting, the FCM data correlated well with cell count data obtained from colony-forming units (CFU) for viable populations. Applicability of the method to several Enterobacteriaceae (different Escherichia coli strains, Salmonella typhimurium, Shigella flexneri 2a) could be shown. The method was validated as a resilient process analytical technology (PAT) tool for the assessment of E-lysis and for particle counting during 20-l batch processes for the production of Escherichia coli Nissle 1917 BGs.

  11. Comparison of rumen bacterial communities in dairy herds of different production.

    Science.gov (United States)

    Indugu, Nagaraju; Vecchiarelli, Bonnie; Baker, Linda D; Ferguson, James D; Vanamala, Jairam K P; Pitta, Dipti W

    2017-08-30

    The purpose of this study was to compare the rumen bacterial composition in high and low yielding dairy cows within and between two dairy herds. Eighty five Holstein dairy cows in mid-lactation (79-179 days in milk) were selected from two farms: Farm 12 (M305 = 12,300 kg; n = 47; 24 primiparous cows, 23 multiparous cows) and Farm 9 (M305 = 9700 kg; n = 38; 19 primiparous cows, 19 multiparous cows). Each study cow was sampled once using the stomach tube method and processed for 16S rRNA gene amplicon sequencing using the Ion Torrent (PGM) platform. Differences in bacterial communities between farms were greater (Adonis: R 2  = 0.16; p forage type and proportion in the diets. A combination of corn silage and alfalfa silage may have contributed to the increased proportion of Proteobacteria in Farm 12. It was concluded that Farm 12 had a greater proportion of specialist bacteria that have the potential to enhance rumen fermentative digestion of feedstuffs to support higher milk yields.

  12. Engineering bacterial biopolymers for the biosorption of heavy metals; new products and novel formulations

    International Nuclear Information System (INIS)

    Gutnick, D.L.; Bach, H.

    2000-01-01

    Bioremediation of heavy metal pollution remains a major challenge in environmental biotechnology. One of the approaches considered for application involves biosorption either to biomass or to isolated biopolymers. Many bacterial polysaccharides have been shown to bind heavy metals with varying degrees of specificity and affinity. While various approaches have been adopted to generate polysaccharide variants altered in both structure and activity, metal biosorption has not been examined. Polymer engineering has included structural modification through the introduction of heterologous genes of the biosynthetic pathway into specific mutants, leading either to alterations in polysaccharide backbone or side chains, or to sugar modification. In addition, novel formulations can be designed which enlarge the family of available bacterial biopolymers for metal-binding and subsequent recovery. An example discussed here is the use of amphipathic bioemulsifiers such as emulsan, produced by the oil-degrading Acinetobacter lwoffii RAG-1, that forms stable, concentrated (70%), oil-in-water emulsions (emulsanosols). In this system metal ions bind primarily at the oil/water interface, enabling their recovery and concentration from relatively dilute solutions. In addition to the genetic modifications described above, a new approach to the generation of amphipathic bioemulsifying formulations is based on the interaction of native or recombinant esterase and its derivatives with emulsan and other water-soluble biopolymers. Cation-binding emulsions are generated from a variety of hydrophobic substrates. The features of these and other systems will be discussed, together with a brief consideratiton of possible applications. (orig.)

  13. Effects of different fermentation methods on bacterial cellulose and acid production by Gluconacetobacter xylinus in Cantonese-style rice vinegar.

    Science.gov (United States)

    Fu, Liang; Chen, Siqian; Yi, Jiulong; Hou, Zongxia

    2014-07-01

    A strain of acidogenic bacterium was isolated from the fermentation liquid of Cantonese-style rice vinegar produced by traditional surface fermentation. 16S rDNA identification confirmed the bacterium as Gluconacetobacter xylinus, which synthesizes bacterial cellulose, and the acid productivity of the strain was investigated. In the study, the effects of the membrane integrity and the comparison of the air-liquid interface membrane with immerged membrane on total acidity, cellulose production, alcohol dehydrogenase (ADH) activity and number of bacteria were investigated. The cellulose membrane and the bacteria were observed under SEM for discussing their relationship. The correlations between oxygen consumption and total acid production rate were compared in surface and shake flask fermentation. The results showed the average acid productivity of the strain was 0.02g/(100mL/h), and the integrity of cellulose membrane in surface fermentation had an important effect on total acidity and cellulose production. With a higher membrane integrity, the total acidity after 144 h of fermentation was 3.75 g/100 mL, and the cellulose production was 1.71 g/100 mL after 360 h of fermentation. However, when the membrane was crushed by mechanical force, the total acidity and the cellulose production were as low as 0.36 g/100 mL and 0.14 g/100 mL, respectively. When the cellulose membrane was forced under the surface of fermentation liquid, the total acid production rate was extremely low, but the activity of ADH in the cellulose membrane was basically the same with the one above the liquid surface. The bacteria were mainly distributed in the cellulose membrane during the fermentation. The bacterial counts in surface fermentation were more than in the shake flask fermentation and G. xylinus consumed the substrate faster, in surface fermentation than in shake flask fermentation. The oxygen consumption rate and total acid production rate of surface fermentation were respectively 26

  14. Laboratory Deposition Apparatus to Study the Effects of Wax Deposition on Pipe Magnetic Field Leakage Signals

    Directory of Open Access Journals (Sweden)

    Karim Mohd Fauzi Abd

    2014-07-01

    Full Text Available Accurate technique for wax deposition detection and severity measurement on cold pipe wall is important for pipeline cleaning program. Usually these techniques are validated by conventional techniques on laboratory scale wax deposition flow loop. However conventional techniques inherent limitations and it is difficult to reproduce a predetermine wax deposit profile and hardness at designated location in flow loop. An alternative wax deposition system which integrates modified pour casting method and cold finger method is presented. This system is suitable to reproduce high volume of medium hard wax deposit in pipe with better control of wax deposit profile and hardness.

  15. Glycerol as a Cheaper Carbon Source in Bacterial Cellulose (BC) Production by Gluconacetobacter Xylinus DSM46604 in Batch Fermentation System

    International Nuclear Information System (INIS)

    Azila Adnan; Nair, G.R.; Roslan Umar; Roslan Umar

    2015-01-01

    Bacterial cellulose (BC) is a polymer of glucose monomers, which has unique properties including high crystallinity and high strength. It has potential to be used in biomedical applications such as making artificial blood vessel, wound dressings, and in the paper making industry. Extensive study on BC aimed to improve BC production such as by using glycerol as a cheaper carbon source. BC was produced in shake flask culture using five different concentrations of glycerol (10, 20, 30, 40 and 50 g/ L). Using concentration of glycerol above 20 g/ L inhibited culture growth and BC production. Further experiments were performed in batch culture (3-L bioreactor) using 20 g/ L glycerol. It produced yield and productivity of 0.15 g/ g and 0.29 g/ L/ day BC, respectively. This is compared with the control medium, 50 g/ L glucose, which only gave yield and productivity of 0.05 g/ g and 0.23 g/ L/ day, respectively. Twenty g/ L of glycerol enhanced BC production by Gluconacetobacter xylinus DSM46604 in batch fermentation system. (author)

  16. Intermittent fasting promotes bacterial clearance and intestinal IgA production in Salmonella typhimurium-infected mice.

    Science.gov (United States)

    Godínez-Victoria, M; Campos-Rodriguez, R; Rivera-Aguilar, V; Lara-Padilla, E; Pacheco-Yepez, J; Jarillo-Luna, R A; Drago-Serrano, M E

    2014-05-01

    The impact of intermittent fasting versus ad libitum feeding during Salmonella typhimurium infection was evaluated in terms of duodenum IgA levels, bacterial clearance and intestinal and extra-intestinal infection susceptibility. Mice that were intermittently fasted for 12 weeks or fed ad libitum were infected with S. typhimurium and assessed at 7 and 14 days post-infection. Next, we evaluated bacterial load in the faeces, Peyer's patches, spleen and liver by plate counting, as well as total and specific intestinal IgA and plasmatic corticosterone levels (by immunoenzymatic assay) and lamina propria IgA levels in plasma cells (by cytofluorometry). Polymeric immunoglobulin receptor, α- and J-chains, Pax-5 factor, pro-inflammatory cytokine (tumour necrosis factor-α and interferon-γ) and anti-inflammatory cytokine (transforming growth factor-β) mRNA levels were assessed in mucosal and liver samples (by real-time PCR). Compared with the infected ad libitum mice, the intermittently fasted infected animals had (1) lower intestinal and systemic bacterial loads; (2) higher SIgA and IgA plasma cell levels; (3) higher mRNA expression of most intestinal parameters; and (4) increased or decreased corticosterone levels on day 7 and 14 post-infection, respectively. No contribution of liver IgA was observed at the intestinal level. Apparently, the changes following metabolic stress induced by intermittent fasting during food deprivation days increased the resistance to S. typhimurium infection by triggering intestinal IgA production and presumably, pathogen elimination by phagocytic inflammatory cells. © 2014 John Wiley & Sons Ltd.

  17. Product formation from thiophene by a mixed bacterial culture. Influence of benzene as growth substrate

    DEFF Research Database (Denmark)

    Rivas, Isabelle Marie; Mosbæk, Hans; Arvin, Erik

    2003-01-01

    phase of transformation. The microorganisms were able to transform thiophene in the absence of benzene at a zero-order rate. Thiophene was converted to five oxidation products, regardless of the presence of benzene. Benzene had no influence on the distribution of these oxidation products. The main...... oxidation product, a thiophene sulphoxide dimer, represented 78+/-12% of the transformed thiophene, while the second most important product, also a thiophene sulphoxide dimer, represented 20+/-2% of the converted thiophene. (C) 2003 Elsevier Science Ltd. All rights reserved....

  18. Unheimlich. From Wax Figures to the Uncanny Valley

    Directory of Open Access Journals (Sweden)

    Pietro Conte

    2012-01-01

    Full Text Available In his pioneering History of Portraiture in Wax, Julius von Schlosser traced back the age-old history of a material which at that time seemed to be already antiquated, if not obsolete. Wax sculptures were rejected and ousted from art history because of their excessive similarity and adherence to models. One hundred years later, however, hyperrealism got its revenge with Maurizio Cattelan’s celebrated hanging children. Moving from that controversial artwork and focusing on the heated polemics over it, my paper will address the question of the well-known Unheimlichkeit of wax figures, investigated by Ernst Jentsch and Sigmund Freud in the early Twentieth Century and nowadays becoming increasingly topical thanks to the recent debate about the existence and nature of the so called Uncanny Valley.

  19. Application of customised bacterial inoculants for grass haylage production and its effectiveness on nutrient composition and fermentation quality of haylage.

    Science.gov (United States)

    Soundharrajan, Ilavenil; Kim, Da Hye; Srisesharam, Srigopalram; Kuppusamy, Palaniselvam; Park, Hyung Soo; Yoon, Yong Hee; Kim, Won Ho; Song, Young Gil; Choi, Ki Choon

    2017-10-01

    The present study aimed to investigate the efficacy of customised Lactobacillus plantarum KCC-10, KCC-19 and K-46 on nutrient composition and fermentation quality of low moisture Italian ryegrass (IRG) forage. An addition of customised bacterial inoculants (CBI) did not affect the nutrient compositions and digestibility rates of haylage. The lactic acid content was higher in CBI-inoculated haylage, whereas the amount of acetic acid and butyric acid production was significantly reduced than the control. CBI-inoculated haylage exhibited higher numbers of bacterial colonies that reduced the pH of the haylage. Low pH in haylage is an important criterion for preventing undesirable microbial growth and improves fermentation quality of haylage. PCR studies indicated that the DNA of L. plantarum was predominantly amplified. It evidenced that the CBI is the main reason behind the improvement of haylage fermentation as compared to control. Overall results suggested that KCC-10, KCC-19 and K-46 are considered as potent strains for improving fermentation quality of low moisture forage and preserve its stability for a long time.

  20. Bacterial natural product biosynthetic domain composition in soil correlates with changes in latitude on a continent-wide scale.

    Science.gov (United States)

    Lemetre, Christophe; Maniko, Jeffrey; Charlop-Powers, Zachary; Sparrow, Ben; Lowe, Andrew J; Brady, Sean F

    2017-10-31

    Although bacterial bioactive metabolites have been one of the most prolific sources of lead structures for the development of small-molecule therapeutics, very little is known about the environmental factors associated with changes in secondary metabolism across natural environments. Large-scale sequencing of environmental microbiomes has the potential to shed light on the richness of bacterial biosynthetic diversity hidden in the environment, how it varies from one environment to the next, and what environmental factors correlate with changes in biosynthetic diversity. In this study, the sequencing of PCR amplicons generated using primers targeting either ketosynthase domains from polyketide biosynthesis or adenylation domains from nonribosomal peptide biosynthesis was used to assess biosynthetic domain composition and richness in soils collected across the Australian continent. Using environmental variables collected at each soil site, we looked for environmental factors that correlated with either high overall domain richness or changes in the domain composition. Among the environmental variables we measured, changes in biosynthetic domain composition correlate most closely with changes in latitude and to a lesser extent changes in pH. Although it is unclear at this time the exact mix of factors that may drive the relationship between biosynthetic domain composition and latitude, from a practical perspective the identification of a latitudinal basis for differences in soil metagenome biosynthetic domain compositions should help guide future natural product discovery efforts. Published under the PNAS license.

  1. Isotope Effects Associated with N2O Production by Fungal and Bacterial Nitric Oxide Reductases: Implications for Enzyme Mechanisms

    Science.gov (United States)

    Hegg, E. L.; Yang, H.; Gandhi, H.; McQuarters, A.; Lehnert, N.; Ostrom, N. E.

    2014-12-01

    Nitrous oxide (N2O) is both a powerful greenhouse gas and a key participant in ozone destruction. Microbial activity accounts for over 70% of the N2O produced annually, and the atmospheric concentration of N2O continues to rise. Because the fungal and bacterial denitrification pathways are major contributors to microbial N2O production, understanding the mechanism by which NO is reduced to N2O will contribute to both N2O source tracing and quantification. Our strategy utilizes stable isotopes to probe the enzymatic mechanism of microbial N2O production. Although the use of stable isotopes to study enzyme mechanisms is not new, our approach is distinct in that we employ both measurements of isotopic preferences of purified enzyme and DFT calculations, thereby providing a synergistic combination of experimental and computational approaches. We analyzed δ18O, δ15Nα (central N atom in N2O), and δ15Nβ (terminal N atom) of N2O produced by purified fungal cytochrome P450 nitric oxide reductase (P450nor) from Histoplasma capsulatum as well as bacterial cytochrome c dependent nitric oxide reductase (cNOR) from Paracoccus denitrificans. P450nor exhibits an inverse kinetic isotope effect for Nβ (KIE = 0.9651) but a normal isotope effect for both Nα (KIE = 1.0127) and the oxygen atom (KIE = 1.0264). These results suggest a mechanism where NO binds to the ferric heme in the P450nor active site and becomes Nβ. Analysis of the NO-binding step indicated a greater difference in zero point energy in the transition state than the ground state, resulting in the inverse KIE observed for Nβ. Following protonation and rearrangement, it is speculated that this complex forms a FeIV-NHOH- species as a key intermediate. Our data are consistent with the second NO (which becomes Nα and O in the N2O product) attacking the FeIV-NHOH- species to generate a FeIII-N2O2H2 complex that enzymatically (as opposed to abiotically) breaks down to release N2O. Conversely, our preliminary data

  2. Calculation of the store house worker dose in a lost wax foundry using MCNP-4C

    International Nuclear Information System (INIS)

    Alegria, N.; Legarda, F.; Herranz, M.; Idoeta, R.

    2005-01-01

    Lost wax casting is an industrial process which permits the transmutation into metal of models made in wax. The wax model is covered with a siliceous shell of the required thickness and once this shell is built the set is heated and wax melted. Liquid metal is then cast into the shell replacing the wax. When the metal is cool, the shell is broken away in order to recover the metallic piece. In this process zircon sands are used for the preparation of the siliceous shell. These sands have varying concentrations of natural radionuclides: 238 U, 232 Th and 235 U together with their progenics. The zircon sand is distributed in bags of 50 kg, and 30 bags are on a pallet, weighing 1,500 kg. The pallets with the bags have dimensions 80 cm x 120 cm x 80 cm, and constitute the radiation source in this case. The only pathway of exposure to workers in the store house is external radiation. In this case there is no dust because the bags are closed and covered by plastic, the store house has a good ventilation rate and so radon accumulation is not possible. The workers do not touch with their hands the bags and consequently skin contamination will not take place. In this study all situations of external irradiation to the workers have been considered; transportation of the pallets from vehicle to store house, lifting the pallets to the shelf, resting of the stock on the shelf, getting down the pallets, and carrying the pallets to production area. Using MCNP-4C exposure situations have been simulated, considering that the source has a homogeneous composition, the minimum stock in the store house is constituted by 7 pallets, and the several distances between pallets and workers when they are at work. The photons flux obtained by MCNP-4C is multiplied by the conversion factor of Flux to Kerma for air by conversion factor to Effective Dose by Kerma unit, and by the number of emitted photons. Those conversion factors are obtained of ICRP 74 table 1 and table 17 respectively. This is

  3. Calculation of the store house worker dose in a lost wax foundry using MCNP-4C.

    Science.gov (United States)

    Alegría, Natalia; Legarda, Fernando; Herranz, Margarita; Idoeta, Raquel

    2005-01-01

    Lost wax casting is an industrial process which permits the transmutation into metal of models made in wax. The wax model is covered with a silicaceous shell of the required thickness and once this shell is built the set is heated and wax melted. Liquid metal is then cast into the shell replacing the wax. When the metal is cool, the shell is broken away in order to recover the metallic piece. In this process zircon sands are used for the preparation of the silicaceous shell. These sands have varying concentrations of natural radionuclides: 238U, 232Th and 235U together with their progenics. The zircon sand is distributed in bags of 50 kg, and 30 bags are on a pallet, weighing 1,500 kg. The pallets with the bags have dimensions 80 cm x 120 cm x 80 cm, and constitute the radiation source in this case. The only pathway of exposure to workers in the store house is external radiation. In this case there is no dust because the bags are closed and covered by plastic, the store house has a good ventilation rate and so radon accumulation is not possible. The workers do not touch with their hands the bags and consequently skin contamination will not take place. In this study all situations of external irradiation to the workers have been considered; transportation of the pallets from vehicle to store house, lifting the pallets to the shelf, resting of the stock on the shelf, getting down the pallets, and carrying the pallets to production area. Using MCNP-4C exposure situations have been simulated, considering that the source has a homogeneous composition, the minimum stock in the store house is constituted by 7 pallets, and the several distances between pallets and workers when they are at work. The photons flux obtained by MCNP-4C is multiplied by the conversion factor of Flux to Kerma for air by conversion factor to Effective Dose by Kerma unit, and by the number of emitted photons. Those conversion factors are obtained of ICRP 74 table 1 and table 17 respectively. This

  4. Bacterial community structure and variation in a full-scale seawater desalination plant for drinking water production

    KAUST Repository

    Belila, Abdelaziz; El Chakhtoura, Joline; Otaibi, N.; Muyzer, G.; Gonzalez-Gil, Graciela; Saikaly, Pascal; van Loosdrecht, Mark C.M.; Vrouwenvelder, Johannes S.

    2016-01-01

    showed that bacterial species richness and diversity decreased during the seawater desalination process. The two-stage RO filtration strongly reduced the water conductivity (>99%), TOC concentration (98.5%) and total bacterial cell number (>99%), albeit

  5. Application of bacterial cytological profiling to crude natural product extracts reveals the antibacterial arsenal of Bacillus subtilis.

    Science.gov (United States)

    Nonejuie, Poochit; Trial, Rachelle M; Newton, Gerald L; Lamsa, Anne; Ranmali Perera, Varahenage; Aguilar, Julieta; Liu, Wei-Ting; Dorrestein, Pieter C; Pogliano, Joe; Pogliano, Kit

    2016-05-01

    Although most clinically used antibiotics are derived from natural products, identifying new antibacterial molecules from natural product extracts is difficult due to the complexity of these extracts and the limited tools to correlate biological activity with specific molecules. Here, we show that bacterial cytological profiling (BCP) provides a rapid method for mechanism of action determination on plates and in complex natural product extracts and for activity-guided purification. We prepared an extract from Bacillus subtilis 3610 that killed the Escherichia coli lptD mutant and used BCP to observe two types of bioactivities in the unfractionated extract: inhibition of translation and permeablization of the cytoplasmic membrane. We used BCP to guide purification of the molecules responsible for each activity, identifying the translation inhibitors bacillaene and bacillaene B (glycosylated bacillaene) and demonstrating that two molecules contribute to cell permeabilitization, the bacteriocin subtilosin and the cyclic peptide sporulation killing factor. Our results suggest that bacillaene mediates translational arrest, and show that bacillaene B has a minimum inhibitory concentration 10 × higher than unmodified bacillaene. Finally, we show that BCP can be used to screen strains on an agar plate without the need for extract preparation, greatly saving time and improving throughput. Thus, BCP simplifies the isolation of novel natural products, by identifying strains, crude extracts and fractions with interesting bioactivities even when multiple activities are present, allowing investigators to focus labor-intensive steps on those with desired activities.

  6. Design and characterization of synthetic fungal-bacterial consortia for direct production of isobutanol from cellulosic biomass.

    Science.gov (United States)

    Minty, Jeremy J; Singer, Marc E; Scholz, Scott A; Bae, Chang-Hoon; Ahn, Jung-Ho; Foster, Clifton E; Liao, James C; Lin, Xiaoxia Nina

    2013-09-03

    Synergistic microbial communities are ubiquitous in nature and exhibit appealing features, such as sophisticated metabolic capabilities and robustness. This has inspired fast-growing interest in engineering synthetic microbial consortia for biotechnology development. However, there are relatively few reports of their use in real-world applications, and achieving population stability and regulation has proven to be challenging. In this work, we bridge ecology theory with engineering principles to develop robust synthetic fungal-bacterial consortia for efficient biosynthesis of valuable products from lignocellulosic feedstocks. The required biological functions are divided between two specialists: the fungus Trichoderma reesei, which secretes cellulase enzymes to hydrolyze lignocellulosic biomass into soluble saccharides, and the bacterium Escherichia coli, which metabolizes soluble saccharides into desired products. We developed and experimentally validated a comprehensive mathematical model for T. reesei/E. coli consortia, providing insights on key determinants of the system's performance. To illustrate the bioprocessing potential of this consortium, we demonstrate direct conversion of microcrystalline cellulose and pretreated corn stover to isobutanol. Without costly nutrient supplementation, we achieved titers up to 1.88 g/L and yields up to 62% of theoretical maximum. In addition, we show that cooperator-cheater dynamics within T. reesei/E. coli consortia lead to stable population equilibria and provide a mechanism for tuning composition. Although we offer isobutanol production as a proof-of-concept application, our modular system could be readily adapted for production of many other valuable biochemicals.

  7. Effect of redox conditions on bacterial and fungal biomass and carbon dioxide production in Louisiana coastal swamp forest sediment

    International Nuclear Information System (INIS)

    Seo, Dong Cheol; DeLaune, Ronald D.

    2010-01-01

    Fungal and bacterial carbon dioxide (CO 2 ) production/emission was determined under a range of redox conditions in sediment from a Louisiana swamp forest used for wastewater treatment. Sediment was incubated in microcosms at 6 Eh levels (-200, -100, 0, + 100, + 250 and + 400 mV) covering the anaerobic range found in wetland soil and sediment. Carbon dioxide production was determined by the substrate-induced respiration (SIR) inhibition method. Cycloheximide (C 15 H 23 NO 4 ) was used as the fungal inhibitor and streptomycin (C 21 H 39 N 7 O 12 ) as the bacterial inhibitor. Under moderately reducing conditions (Eh > + 250 mV), fungi contributed more than bacteria to the CO 2 production. Under highly reducing conditions (Eh ≤ 0 mV), bacteria contributed more than fungi to the total CO 2 production. The fungi/bacteria (F/B) ratios varied between 0.71-1.16 for microbial biomass C, and 0.54-0.94 for microbial biomass N. Under moderately reducing conditions (Eh ≥ + 100 mV), the F/B ratios for microbial biomass C and N were higher than that for highly reducing conditions (Eh ≤ 0 mV). In moderately reducing conditions (Eh ≥ + 100 mV), the C/N microbial biomass ratio for fungi (C/N: 13.54-14.26) was slightly higher than for bacteria (C/N: 9.61-12.07). Under highly reducing redox conditions (Eh ≤ 0 mV), the C/N microbial biomass ratio for fungi (C/N: 10.79-12.41) was higher than for bacteria (C/N: 8.21-9.14). For bacteria and fungi, the C/N microbial biomass ratios under moderately reducing conditions were higher than that in highly reducing conditions. Fungal CO 2 production from swamp forest could be of greater ecological significance under moderately reducing sediment conditions contributing to the greenhouse effect (GHE) and the global warming potential (GWP). However, increases in coastal submergence associated with global sea level rise and resultant decrease in sediment redox potential from increased flooding would likely shift CO 2 production to bacteria

  8. Cannabis-induced psychosis associated with high potency "wax dabs".

    Science.gov (United States)

    Pierre, Joseph M; Gandal, Michael; Son, Maya

    2016-04-01

    With mounting evidence that the risk of cannabis-induced psychosis may be related to both dose and potency of tetrahydrocannbinol (THC), increasing reports of psychosis associated with cannabinoids containing greater amounts of THC are anticipated. We report two cases of emergent psychosis after using a concentrated THC extract known as cannabis "wax," "oil," or "dabs" raising serious concerns about its psychotic liability. Although "dabbing" with cannabis wax is becoming increasingly popular in the US for both recreational and "medicinal" intentions, our cases raise serious concerns about its psychotic liability and highlight the importance of understanding this risk by physicians recommending cannabinoids for purported medicinal purposes. Published by Elsevier B.V.

  9. Wax Precipitation Modeled with Many Mixed Solid Phases

    DEFF Research Database (Denmark)

    Heidemann, Robert A.; Madsen, Jesper; Stenby, Erling Halfdan

    2005-01-01

    The behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows sub......-temperature and low-temperature forms, are pure. Model calculations compare well with the data of Pauly et al. for C18 to C30 waxes precipitating from n-decane solutions. (C) 2004 American Institute of Chemical Engineers....

  10. Three-dimensional wax patterning of paper fluidic devices.

    Science.gov (United States)

    Renault, Christophe; Koehne, Jessica; Ricco, Antonio J; Crooks, Richard M

    2014-06-17

    In this paper we describe a method for three-dimensional wax patterning of microfluidic paper-based analytical devices (μPADs). The method is rooted in the fundamental details of wax transport in paper and provides a simple way to fabricate complex channel architectures such as hemichannels and fully enclosed channels. We show that three-dimensional μPADs can be fabricated with half as much paper by using hemichannels rather than ordinary open channels. We also provide evidence that fully enclosed channels are efficiently isolated from the exterior environment, decreasing contamination risks, simplifying the handling of the device, and slowing evaporation of solvents.

  11. Production and characterization of nanospheres of bacterial cellulose from Acetobacter xylinum from processed rice bark

    International Nuclear Information System (INIS)

    Goelzer, F.D.E.; Faria-Tischer, P.C.S.; Vitorino, J.C.; Sierakowski, Maria-R.; Tischer, C.A.

    2009-01-01

    Bacterial cellulose (BC), biosynthesized by Acetobacter xylinum, was produced in a medium consisting of rice bark pre-treated with an enzymatic pool. Rice bark was evaluated as a carbon source by complete enzymatic hydrolysis and monosaccharide composition (GC-MS of derived alditol acetates). It was treated enzymatically and then enriched with glucose up to 4% (w/v). The BC produced by static and aerated processes was purified by immersion in 0.1 M NaOH, was characterized by FT-IR, X-ray diffraction and the biosynthetic nanostructures were evaluated by Scanning Electronic (SEM), Transmission Electronic (TEM) and Atomic Force Microscopy (AFM). The BC films arising from static fermentation with rice bark/glucose and glucose are tightly intertwined, partially crystalline, being type II cellulose produced with rice bark/glucose, and type I to the produced in a glucose medium. The nanostructurated biopolymer obtained from the rice bark/glucose medium, produced in a reactor with air flux had micro- and nanospheres linked to nanofibers of cellulose. These results indicate that the bark components, namely lignins, hemicelluloses or mineral contents, interact with the cellulose forming micro- and nanostructures with potential use to incorporate drugs

  12. The SOS chromotest: bacterial cells to detect and characterize genotoxic products and radiations

    International Nuclear Information System (INIS)

    Quillardet, P.; Hofnung, M.

    1994-01-01

    The advanced knowledge we have on the bacterium Escherichia coli has facilitated the development of the colorimetric and fast assay, the SOS chromotest, which involves a single tester strain and gives a qualitative and a quantitative assay of the action of a genotoxic agent. We discuss a number of possibilities opened by this test in order to make a genetic diagnosis of the chemical nature of the damages caused in the genetic material by means of a battery of strains which have been genetically modified for that purpose. In order to give an idea of the accuracy of the bacterial responses and of the way they can be used to characterize the DNA damage by a genetic approach, the case of alkylating agents is described in a relatively detailed fashion, and the case of oxidative agents is rapidly mentioned. The sensitivity to ionizing radiation is such that the test is able to detect doses of the order of 1 Gy. We discuss briefly how it could be possible to increase this sensitivity by genetically inactivating repair systems which process the injuries caused by these agents, and how the use of a battery of tester strains could also give information on the nature of injuries caused by various types of ionizing radiation. (authors). 39 refs. 4 figs. 1 tab

  13. Effect of organic acids production and bacterial community on the possible mechanism of phosphorus solubilization during composting with enriched phosphate-solubilizing bacteria inoculation.

    Science.gov (United States)

    Wei, Yuquan; Zhao, Yue; Shi, Mingzi; Cao, Zhenyu; Lu, Qian; Yang, Tianxue; Fan, Yuying; Wei, Zimin

    2018-01-01

    Enriched phosphate-solubilizing bacteria (PSB) agent were acquired by domesticated cultivation, and inoculated into kitchen waste composting in different stages. The effect of different treatments on organic acids production, tricalcium phosphate (TCP) solubilization and their relationship with bacterial community were investigated during composting. Our results pointed out that inoculation affected pH, total acidity and the production of oxalic, lactic, citric, succinic, acetic and formic acids. We also found a strong advantage in the solubilization of TCP and phosphorus (P) availability for PSB inoculation especially in the cooling stage. Redundancy analysis and structural equation models demonstrated inoculation by different methods changed the correlation of the bacterial community composition with P fractions as well as organic acids, and strengthened the cooperative function related to P transformation among species during composting. Finally, we proposed a possible mechanism of P solubilization with enriched PSB inoculation, which was induced by bacterial community and organic acids production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Successful phytoremediation of crude-oil contaminated soil at an oil exploration and production company by plants-bacterial synergism.

    Science.gov (United States)

    Fatima, Kaneez; Imran, Asma; Amin, Imran; Khan, Qaiser M; Afzal, Muhammad

    2018-06-07

    Phytoremediation is a promising approach for the cleanup of soil contaminated with petroleum hydrocarbons. This study aimed to develop plant-bacterial synergism for the successful remediation of crude oil-contaminated soil. A consortia of three endophytic bacteria was augmented to two grasses, Leptochloa fusca and Brachiaria mutica, grown in oil-contaminated soil (46.8 g oil kg -1 soil) in the vicinity of an oil exploration and production company. Endophytes augmentation improved plant growth, crude oil degradation, and soil health. Maximum oil degradation (80%) was achieved with B. mutica plants augmented with the endophytes and it was significantly (P oil reduction indicates that catabolic gene expression is important for hydrocarbon mineralization. This investigation showed that the use of endophytes with appropriate plant is an effective strategy for the cleanup of oil-contaminated soil under field conditions.

  15. Exposure to bacterial signals does not alter pea aphids' survival upon a second challenge or investment in production of winged offspring.

    Directory of Open Access Journals (Sweden)

    Bas ter Braak

    Full Text Available Pea aphids have an obligate nutritional symbiosis with the bacteria Buchneraaphidicola and frequently also harbor one or more facultative symbionts. Aphids are also susceptible to bacterial pathogen infections, and it has been suggested that aphids have a limited immune response towards such pathogen infections compared to other, more well-studied insects. However, aphids do possess at least some of the genes known to be involved in bacterial immune responses in other insects, and immune-competent hemocytes. One possibility is that immune priming with microbial elicitors could stimulate immune protection against subsequent bacterial infections, as has been observed in several other insect systems. To address this hypothesis we challenged aphids with bacterial immune elicitors twenty-four hours prior to live bacterial pathogen infections and then compared their survival rates to aphids that were not pre-exposed to bacterial signals. Using two aphid genotypes, we found no evidence for immune protection conferred by immune priming during infections with either Serratia marcescens or with Escherichia coli. Immune priming was not altered by the presence of facultative, beneficial symbionts in the aphids. In the absence of inducible immune protection, aphids may allocate energy towards other defense traits, including production of offspring with wings that could escape deteriorating conditions. To test this, we monitored the ratio of winged to unwinged offspring produced by adult mothers of a single clone that had been exposed to bacterial immune elicitors, to live E. coli infections or to no challenge. We found no correlation between immune challenge and winged offspring production, suggesting that this mechanism of defense, which functions upon exposure to fungal pathogens, is not central to aphid responses to bacterial infections.

  16. High-level accumulation of oleyl oleate in plant seed oil by abundant supply of oleic acid substrates to efficient wax ester synthesis enzymes.

    Science.gov (United States)

    Yu, Dan; Hornung, Ellen; Iven, Tim; Feussner, Ivo

    2018-01-01

    Biotechnology enables the production of high-valued industrial feedstocks from plant seed oil. The plant-derived wax esters with long-chain monounsaturated acyl moieties, like oleyl oleate, have favorite properties for lubrication. For biosynthesis of wax esters using acyl-CoA substrates, expressions of a fatty acyl reductase (FAR) and a wax synthase (WS) in seeds are sufficient. For optimization of the enzymatic activity and subcellular localization of wax ester synthesis enzymes, two fusion proteins were created, which showed wax ester-forming activities in Saccharomyces cerevisiae . To promote the formation of oleyl oleate in seed oil, WSs from Acinetobactor baylyi ( Ab WSD1) and Marinobacter aquaeolei ( Ma WS2), as well as the two created fusion proteins were tested in Arabidopsis to evaluate their abilities and substrate preference for wax ester production. The tested seven enzyme combinations resulted in different yields and compositions of wax esters. Expression of a FAR of Marinobacter aquaeolei ( Ma FAR) with Ab WSD1 or Ma WS2 led to a high incorporation of C 18 substrates in wax esters. The Ma FAR/TM Mm AWAT2- Ab WSD1 combination resulted in the incorporation of more C 18:1 alcohol and C 18:0 acyl moieties into wax esters compared with Ma FAR/ Ab WSD1. The fusion protein of a WS from Simmondsia chinensis ( Sc WS) with MaFAR exhibited higher specificity toward C 20:1 substrates in preference to C 18:1 substrates. Expression of Ma FAR/ Ab WSD1 in the Arabidopsis fad2 fae1 double mutant resulted in the accumulation of oleyl oleate (18:1/18:1) in up to 62 mol% of total wax esters in seed oil, which was much higher than the 15 mol% reached by Ma FAR/ Ab WSD1 in Arabidopsis Col-0 background. In order to increase the level of oleyl oleate in seed oil of Camelina , lines expressing Ma FAR/ Sc WS were crossed with a transgenic high oleate line. The resulting plants accumulated up to >40 mg g seed -1 of wax esters, containing 27-34 mol% oleyl oleate. The

  17. Effect of partially replacing a barley-based concentrate with flaxseed-based products on the rumen bacterial population of lactating Holstein dairy cows.

    Science.gov (United States)

    Castillo-Lopez, E; Moats, J; Aluthge, N D; Ramirez Ramirez, H A; Christensen, D A; Mutsvangwa, T; Penner, G B; Fernando, S C

    2018-01-01

    The effects of partial replacement of a barley-based concentrate with flaxseed-based products on the rumen bacterial population of lactating Holstein dairy cows were evaluated. Treatments fed were CONT, a normal diet that included barley silage, alfalfa hay and a barley-based concentrate that contained no flaxseed or faba beans; FLAX, inclusion of a nonextruded flaxseed-based product containing 55·0% flaxseed, 37·8% field peas and 6·9% alfalfa; EXT, similar to FLAX, but the product was extruded and EXTT, similar to FLAX, but product was extruded and field peas were replaced by high-tannin faba beans. The rumen bacterial population was evaluated by utilizing 16S rRNA gene sequencing. Most abundant phyla, families and genera were unaffected. However, some taxa were affected; for example, unsaturated fatty acid content was negatively correlated with Clostridiaceae, and tannin content was negatively correlated with BS11 and Paraprevotellaceae. Predominant rumen bacterial taxa were not affected, but the abundance of some taxa found in lower proportions shifted, possibly due to sensitivity to unsaturated fatty acids or tannins. Flaxseed-based products were effective for partially replacing barley-based concentrate in rations of lactating dairy cows. No negative effects of these products were observed on the abundance of predominant rumen bacterial taxa, with only minor shifts in less abundant bacteria. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.

  18. Use of bacterial co-cultures for the efficient production of chemicals.

    Science.gov (United States)

    Jones, J Andrew; Wang, Xin

    2017-12-02

    The microbial production of chemicals has traditionally relied on a single engineered microbe to enable the complete bioconversion of substrate to final product. Recently, a growing fraction of research has transitioned towards employing a modular co-culture engineering strategy using multiple microbes growing together to facilitate a divide-and-conquer approach for chemical biosynthesis. Here, we review key success stories that leverage the unique advantages of co-culture engineering, while also addressing the critical concerns that will limit the wide-spread implementation of this technology. Future studies that address the need to monitor and control the population dynamics of each strain module, while maintaining robust flux routes towards a wide range of desired products will lead the efforts to realize the true potential of co-culture engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Bacterial L-arabinose isomerases: industrial application for D-tagatose production.

    Science.gov (United States)

    Boudebbouze, Samira; Maguin, Emmanuelle; Rhimi, Moez

    2011-12-01

    D-tagatose is a natural monosaccharide with a low caloric value and has an anti-hyperglycemiant effect. This hexose has potential applications both in pharmaceutical and agro-food industries. However, the use of D-tagatose remains limited by its production cost. Many production procedures including chemical and biological processes were developed and patented. The most profitable production way is based on the use of L-arabinose isomerase which allows the manufacture of D-tagatose with an attractive rate. Future developments are focused on the generation of L-arabinose isomerases having biochemical properties satisfying the industrial applications. This report provides a brief review of the most recent patents that have been published relating to this area.

  20. Development of a Bacterial Biosensor for Rapid Screening of Yeast p-Coumaric Acid Production

    DEFF Research Database (Denmark)

    Siedler, Solvej; Khatri, Narendar K.; Zsohar, Andrea

    2017-01-01

    device, rapidly sort droplets containing yeast cells producing high amounts of extracellular p-coumaric acid using the fluorescent E. coli biosensor signal. As additional biosensors become available, such approaches will find broad applications for screening of an extracellular product.......Transcription factor-based biosensors are used to identify producer strains, a critical bottleneck in cell factory engineering. Here, we address two challenges with this methodology: transplantation of heterologous transcriptional regulators into new hosts to generate functional biosensors...... and biosensing of the extracellular product concentration that accurately reflects the effective cell factory production capacity. We describe the effects of different translation initiation rates on the dynamic range of a p-coumaric acid biosensor based on the Bacillus subtilis transcriptional repressor Pad...

  1. Simultaneous biogas upgrading and biochemicals production using anaerobic bacterial mixed cultures

    DEFF Research Database (Denmark)

    Omar, Basma; Abou-Shanab, Reda; El-Gammal, Maie

    2018-01-01

    , the biogas was upgraded to biomethane (CH4 >95%), which can be used as a vehicle fuel or injected into the natural gas grid. To establish an efficient fermentative microbial platform, a thermal (at two different temperatures of 70 °C and 90 °C) and a chemical pretreatment method using 2-bromoethanesulfonate...... treatment methods and gas ratios has also been unravelled using 16S rRNA analysis. The chemical treatment of the inoculum had successfully blocked the activity of methanogens and enhanced the VFAs production, especially acetate. The chemical treatment led to a significantly better acetate production (291 mg...

  2. Influence of the wax application time on cassava conservation; Influencia del momento de aplicación de un recubrimiento en la conservación de yuca

    Directory of Open Access Journals (Sweden)

    Oscar Rendón

    2012-12-01

    Full Text Available This article, product of a research project, shows the results of the evaluation of the influence of the time between harvest and the application of a natural wax in the deterioration of cassava roots; this time was called time of application. Tao chemistry Ltda. wax TAO FRESH ROOT was used in the development of this work. Three factors were considered for the evaluation:the quality of cassava roots, such as: physiological deterioration, loss of weight and dry matter content. They were evaluated in two varieties of cassava,five moments of application (1, 3, 6, 12 and 24 h for a period of 21 days. The moment of application at 6 h presented the lowest averages of physiological deterioration and weight loss.This article is presented to establish the potential ofnatural waxes as a technique for the preservation of cassavaroots, highlighting the moment of application as an influential factor in the extension of the life of this product.

  3. Bacterial contaminants from frozen puff pastry production process and their growth inhibition by antimicrobial substances from lactic acid bacteria.

    Science.gov (United States)

    Rumjuankiat, Kittaporn; Keawsompong, Suttipun; Nitisinprasert, Sunee

    2017-05-01

    Seventy-five bacterial contaminants which still persisted to cleaning system from three puff pastry production lines (dough forming, layer and filling forming, and shock freezing) were identified using 16S rDNA as seven genera of Bacillus , Corynebacterium , Dermacoccus , Enterobacter , Klebsiella, Pseudomonas , and Staphylococcus with detection frequencies of 24.00, 2.66, 1.33, 37.33, 1.33, 2.66, and 30.66, respectively. Seventeen species were discovered while only 11 species Bacillus cereus, B. subtilis, B. pumilus, Corynebacterium striatum , Dermacoccus barathri , Enterobacter asburiae, Staphylococcus kloosii, S. haemolyticus, S. hominis, S. warneri , and S. aureus were detected at the end of production. Based on their abundance, the highest abundance of E. asburiae could be used as a biomarker for product quality. While a low abundance of the mesophile pathogen C. striatum , which causes respiratory and nervous infection and appeared only at the shock freezing step was firstly reported for its detection in bakery product. Six antimicrobial substances (AMSs) from lactic acid bacteria, FF1-4, FF1-7, PFUR-242, PFUR-255, PP-174, and nisin A were tested for their inhibition activities against the contaminants. The three most effective were FF1-7, PP-174, and nisin A exhibiting wide inhibition spectra of 88.00%, 85.33%, and 86.66%, respectively. The potential of a disinfectant solution containing 800 AU/ml of PP-174 and nisin A against the most resistant strains of Enterobacter , Staphylococcus , Bacillus and Klebsiella was determined on artificially contaminated conveyor belt coupons at 0, 4, 8, 12, and 16 hr. The survival levels of the test strains were below 1 log CFU/coupon at 0 hr. The results suggested that a combined solution of PP-174 and nisin A may be beneficial as a sanitizer to inhibit bacterial contaminants in the frozen puff pastry industry.

  4. Repurposing a bacterial quality control mechanism to enhance enzyme production in living cells

    Science.gov (United States)

    Heterologous expression of many proteins in bacteria, yeasts, and plants is often limited by low titers of functional protein. To address this problem, we have created a two-tiered directed evolution strategy in Escherichia coli that enables optimization of protein production while maintaining high ...

  5. A bacterial cell factory for efficient production of ethanol from whey

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates to a method for homo-ethanol production from lactose using a genetically modified lactic acid bacterium of the invention, where the cells are provided with a substrate comprising dairy waste supplemented with an amino nitrogen source (such as acid hydrolysed corn steep liquo...

  6. Limited bacterial diversity within a treatment plant receiving antibiotic containing waste from bulk drug production

    NARCIS (Netherlands)

    Marathe, Nachiket P.; Shetty, Sudarshan A.; Shouche, Yogesh S.; Larsson, D.G.J.

    2016-01-01

    Biological treatment of waste water from bulk drug production, contaminated with high levels of fluoroquinolone antibiotics, can lead to massive enrichment of antibiotic resistant bacteria, resistance genes and associated mobile elements, as previously shown. Such strong selection may be boosted

  7. Mucosal Immune Regulation in Intestinal Disease. The role of bacterial products, food components and drugs

    NARCIS (Netherlands)

    Bol-Schoenmakers, M.

    2009-01-01

    The challenge of the mucosal gut associated immune system is to remain unresponsive to food products and commensal microbiota, while mounting an appropriate immune response towards pathogens. This implicates the necessity of tight immune regulation within the gut associated lymphoid tissue (GALT).

  8. ASPHALT-RESIN-WAX DEPOSITS ANALYSIS WITH PETROLEUM REFINERY EQUIPMENT USAGE

    Directory of Open Access Journals (Sweden)

    Nadejda Bondar

    2013-12-01

    Full Text Available The methodology and analysis of wax deposits formed in-water-cooling tower, cistern and tank from wax petroleum were developed. It was shown, that deposits consist of organic (>90% and inorganic components – the first one was enriched by high molecular wax hydrocarbons, the second one – by mechanical impurities. The methods of deposits utilization were proposed

  9. Wax-incorporated emulsion gel beads of calcium pectinate for intragastric floating drug delivery.

    Science.gov (United States)

    Sriamornsak, Pornsak; Asavapichayont, Panida; Nunthanid, Jurairat; Luangtana-Anan, Manee; Limmatvapirat, Sontaya; Piriyaprasarth, Suchada

    2008-01-01

    The purpose of this study was to prepare wax-incorporated pectin-based emulsion gel beads using a modified emulsion-gelation method. The waxes in pectin-olive oil mixtures containing a model drug, metronidazole, were hot-melted, homogenized and then extruded into calcium chloride solution. The beads formed were separated, washed with distilled water and dried for 12 h. The influence of various types and amounts of wax on floating and drug release behavior of emulsion gel beads of calcium pectinate was investigated. The drug-loaded gel beads were found to float on simulated gastric fluid if the sufficient amount of oil was used. Incorporation of wax into the emulsion gel beads affected the drug release. Water-soluble wax (i.e. polyethylene glycol) increased the drug release while other water-insoluble waxes (i.e. glyceryl monostearate, stearyl alcohol, carnauba wax, spermaceti wax and white wax) significantly retarded the drug release. Different waxes had a slight effect on the drug release. However, the increased amount of incorporated wax in the formulations significantly sustained the drug release while the beads remained floating. The results suggest that wax-incorporated emulsion gel beads could be used as a carrier for intragastric floating drug delivery.

  10. Gourds: Bitter, Bottle, Wax, Snake, Sponge and Ridge

    Science.gov (United States)

    Minor cucurbits include bitter gourd, bottle gourd, wax gourd, snake gourd, and sponge and ridge gourd, which are significant dietary sources of nutrients such as vitamin A and C, iron and calcium. These cucurbits are cultivated and marketed by smallholder farmers and remain important components of ...

  11. Effects of wax treatment on quality and postharvest physiology of ...

    African Journals Online (AJOL)

    ... cell membrane permeability and malondialdehyde content when compared with those in control. This waxing also improved total sugars and the contents of ascorbic acid in pineapple fruits. These results suggested that this treatment might be a useful technique to alleviate chilling injury and maintain fruit quality during ...

  12. Structural characterization of wax esters by electron ionization mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Klára; Vrkoslav, Vladimír; Valterová, Irena; Háková, Martina; Cvačka, Josef

    2012-01-01

    Roč. 53, č. 1 (2012), s. 204-213 ISSN 0022-2275 R&D Projects: GA ČR GA203/09/0139 Institutional research plan: CEZ:AV0Z40550506 Keywords : interpretation * neutral lipids * spectral database * waxes Subject RIV: CC - Organic Chemistry Impact factor: 4.386, year: 2012

  13. Uncovered secret of a Vasseur-Tramond wax model.

    Science.gov (United States)

    Pastor, J F; Gutiérrez, B; Montes, J M; Ballestriero, R

    2016-01-01

    The technique of anatomical wax modelling reached its heyday in Italy during the 18th century, through a fruitful collaboration between sculptors and anatomists. It soon spread to other countries, and prestigious schools were created in England, France, Spain and Austria. Paris subsequently replaced Italy as the major centre of manufacture, and anatomical waxes were created there from the mid-19th century in workshops such as that of Vasseur-Tramond. This workshop began to sell waxes to European Faculties of Medicine and Schools of Surgery around 1880. Little is known of the technique employed in the creation of such artefacts as this was deemed a professional secret. To gain some insight into the methods of construction, we have studied a Vasseur-Tramond wax model in the Valladolid University Anatomy Museum, Spain, by means of multi-slice computerised tomography and X-ray analysis by means of environmental scanning electron microscopy. Scanning electron microscopy was used to examine the hair. These results have revealed some of the methods used to make these anatomical models and the materials employed. © 2015 Anatomical Society.

  14. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar

    2005-01-01

    The paper summarizes the experimental work done on asphaltene influenced wax crystallization. Three different asphaltenes (from stable oil, instable oil, and deposit) were mixed at several concentrations or dispersions into the waxy crude oil. These blends were evaluated by viscometry and yield s...

  15. Leaf waxes in litter and topsoils along a European transect

    Czech Academy of Sciences Publication Activity Database

    Schäfer, I. K.; Lanny, V.; Franke, J.; Eglinton, T. I.; Zech, M.; Vysloužilová, Barbora; Zech, R.

    2016-01-01

    Roč. 2, č. 4 (2016), s. 551-564 ISSN 2199-3971 Institutional support: RVO:67985912 Keywords : leaf waxes * soil s Subject RIV: AC - Archeology, Anthropology, Ethnology http://www. soil -journal.net/2/551/2016/ soil -2-551-2016.pdf

  16. Investigation of wax precipitation in crude oil: Experimental and modeling

    Directory of Open Access Journals (Sweden)

    Taraneh Jafari Behbahani

    2015-09-01

    Full Text Available In this work, a series of experiments were carried to investigation of rheological behavior of crude oil using waxy crude oil sample in the absence/presence of flow improver such as ethylene-vinyl acetate copolymer. The rheological data covered the temperature range of 5–30 °C. The results indicated that the performance of flow improver was dependent on its molecular weight. Addition of small quantities of flow improver, can improve viscosity and pour point of crude oil. Also, an Artificial Neural Network (ANN model using Multi-Layer Perceptron (MLP topology has been developed to account wax appearance temperature and the amount of precipitated wax and the model was verified using experimental data given in this work and reported in the literature. In order to compare the performance of the proposed model based on Artificial Neural Network, the wax precipitation experimental data at different temperatures were predicted using solid solution model and multi-solid phase model. The results showed that the developed model based on Artificial Neural Network can predict more accurately the wax precipitation experimental data in comparison to the previous models such as solid solution and multi-solid phase model with AADs less than 0.5%. Furthermore, the number of parameters required for the Artificial Neural Network (ANN model is less than the studied thermodynamic models.

  17. EPICUTICULAR WAX COMPOSITION OF SOME EUROPEAN SEDUM SPECIES

    NARCIS (Netherlands)

    STEVENS, JF; THART, H; BOLCK, A; ZWAVING, JH; MALINGRE, TM

    Epicuticular waxes from 30 species of Sedum and 2 species of Sempervivoideae, i.e. Aeonium spathulatum and Sempervivum nevadense, have been analysed by GC and GC-MS. The Sedum taxa examined were S. acre, S. album, S. series Alpestria (13 species), S. anglicum, S. brevifolium, S. litoreum, S. lydium,

  18. Preparation and Characterization of Sugar Cane Wax Microspheres ...

    African Journals Online (AJOL)

    ... and characterize indomethacin (IM) microspheres prepared with sugar cane wax microsperes. Methods: Microspheres were prepared by melt-emulsified dispersion and cooling-induced solidification method. The microspheres were characterized by scanning electron microscopy (SEM) and differntial scanning calorimetry ...

  19. TARSyn: Tunable Antibiotic Resistance Devices Enabling Bacterial Synthetic Evolution and Protein Production

    DEFF Research Database (Denmark)

    Rennig, Maja; Martinez, Virginia; Mirzadeh, Kiavash

    2018-01-01

    Evolution can be harnessed to optimize synthetic biology designs. A prominent example is recombinant protein production-a dominating theme in biotechnology for more than three decades. Typically, a protein coding sequence (cds) is recombined with genetic elements, such as promoters, ribosome...... and allows expression levels in large clone libraries to be probed using a simple cell survival assay on the respective antibiotic. The power of the approach is demonstrated by substantially increasing production of two commercially interesting proteins, a Nanobody and an Affibody. The method is a simple......-level expression-an example of synthetic evolution. However, manual screening limits the ability to assay expression levels of all putative sequences in the libraries. Here we have solved this bottleneck by designing a collection of translational coupling devices based on a RNA secondary structure. Exchange...

  20. A secretory system for bacterial production of high-profile protein targets

    DEFF Research Database (Denmark)

    Kotzsch, Alexander; Vernet, Erik; Hammarström, Martin

    2011-01-01

    Escherichia coli represents a robust, inexpensive expression host for the production of recombinant proteins. However, one major limitation is that certain protein classes do not express well in a biologically relevant form using standard expression approaches in the cytoplasm of E. coli. To impr......Escherichia coli represents a robust, inexpensive expression host for the production of recombinant proteins. However, one major limitation is that certain protein classes do not express well in a biologically relevant form using standard expression approaches in the cytoplasm of E. coli...... membrane protein F (OmpF) and osmotically inducible protein Y (OsmY). Based on the results of this initial study, we carried out an extended expression screen employing the OsmY fusion and multiple constructs of a more diverse set of human proteins. Using this high-throughput compatible system, we clearly...

  1. The Genome-Based Metabolic Systems Engineering to Boost Levan Production in a Halophilic Bacterial Model.

    Science.gov (United States)

    Aydin, Busra; Ozer, Tugba; Oner, Ebru Toksoy; Arga, Kazim Yalcin

    2018-03-01

    Metabolic systems engineering is being used to redirect microbial metabolism for the overproduction of chemicals of interest with the aim of transforming microbial hosts into cellular factories. In this study, a genome-based metabolic systems engineering approach was designed and performed to improve biopolymer biosynthesis capability of a moderately halophilic bacterium Halomonas smyrnensis AAD6 T producing levan, which is a fructose homopolymer with many potential uses in various industries and medicine. For this purpose, the genome-scale metabolic model for AAD6 T was used to characterize the metabolic resource allocation, specifically to design metabolic engineering strategies for engineered bacteria with enhanced levan production capability. Simulations were performed in silico to determine optimal gene knockout strategies to develop new strains with enhanced levan production capability. The majority of the gene knockout strategies emphasized the vital role of the fructose uptake mechanism, and pointed out the fructose-specific phosphotransferase system (PTS fru ) as the most promising target for further metabolic engineering studies. Therefore, the PTS fru of AAD6 T was restructured with insertional mutagenesis and triparental mating techniques to construct a novel, engineered H. smyrnensis strain, BMA14. Fermentation experiments were carried out to demonstrate the high efficiency of the mutant strain BMA14 in terms of final levan concentration, sucrose consumption rate, and sucrose conversion efficiency, when compared to the AAD6 T . The genome-based metabolic systems engineering approach presented in this study might be considered an efficient framework to redirect microbial metabolism for the overproduction of chemicals of interest, and the novel strain BMA14 might be considered a potential microbial cell factory for further studies aimed to design levan production processes with lower production costs.

  2. Strategies for production of active eukaryotic proteins in bacterial expression system

    Institute of Scientific and Technical Information of China (English)

    Orawan Khow; Sunutcha Suntrarachun

    2012-01-01

    Bacteria have long been the favorite expression system for recombinant protein production. However, the flaw of the system is that insoluble and inactive proteins are co-produced due to codon bias, protein folding, phosphorylation, glycosylation, mRNA stability and promoter strength. Factors are cited and the methods to convert to soluble and active proteins are described, for example a tight control of Escherichia coli milieu, refolding from inclusion body and through fusion technology.

  3. Food safety in raw milk production: risk factors associated to bacterial DNA contamination.

    Science.gov (United States)

    Cerva, Cristine; Bremm, Carolina; Reis, Emily Marques dos; Bezerra, André Vinícius Andrade; Loiko, Márcia Regina; Cruz, Cláudio Estêvão Farias da; Cenci, Alexander; Mayer, Fabiana Quoos

    2014-06-01

    While human illness from milkborne pathogens may be linked to contamination of the product after pasteurization or improper pasteurization, such diseases are usually associated with consumption of raw milk or its by-products. Molecular biology tools were applied to investigate contamination by Listeria monocytogenes, Salmonella spp., some pathogenic strains of Escherichia coli, and Campylobacter jejuni in 548 raw milk samples from 125 dairy farms established in two regions from southern Brazil. Moreover, 15 variables were evaluated for their association with raw milk contamination levels, and the risk factors were determined by multiple regression analysis. Salmonella spp. were more frequently detected, followed by pathogenic E. coli. There was difference in contamination index between the regions, in which risk factors such as temporary cattle confinement, low milk production, low milking machine cleaning frequency, and milk storage area without tile walls were identified. The risk factors were specific to each region studied. Nevertheless, the data can be used to improve milk quality of dairy farms/herds with similar management practices.

  4. The effect of temperature and effluent recycle rate on hydrogen production by undefined bacterial granules.

    Science.gov (United States)

    Ngoma, L; Masilela, P; Obazu, F; Gray, V M

    2011-10-01

    Biohydrogen production in an anaerobic fluidized granular bed bioreactor was strongly dependent on temperature and effluent recycle rates. At 45 °C as the effluent recycle rate was increased from 1.3 to 3.5 L/min, the total H₂ output for the bioreactor increased from 10.6 to 43.2 L/h. Volumetric H(2) productivity also increased from 2.1 to 8.7 L H₂/L/h. At 70°C as the effluent recycle was increased from 1.3 to 3.5 L/min, the total H₂ output for the bioreactor increased from 13.8 to 73.8L/h. At 70 °C volumetric H(2) productivities increased from 2.8 to 14.8L H₂/L/h as the effluent recycle rate was increased from 1.3 to 3.5 L/min. At 45 °C % H₂ was 45% and reached 67% at 70 °C. Maximum hydrogen yields at 45 °C were 1.24 and 2.2 mol H₂/mol glucose at 70 °C. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Bacterial laminarinase for application in ethanol production from brown algae Sargassum sp. using halotolerant yeast

    Directory of Open Access Journals (Sweden)

    C.M.T. Perez

    2018-03-01

    Full Text Available Macroalgae are known to have many industrial applications, with current research targeting the potential of macroalgal biomass as feedstock in production of biofuels. Marine algal biomass is rich in storage carbohydrates, laminarin, and cellulose, which can be converted to fermentable sugars using appropriate enzymes, for fermentation to ethanol. This study focused on ethanol production from macroalgae using only enzymatic treatment for saccharification of algal biomass. This involved the isolation and identification of cellulase and laminarinase-producing microorganisms from mangrove area in the Philippines and production of partially purified enzymes for algal biomass saccharification. Results showed that the partially purified laminarinase produced from Bacillus sp. was capable of hydrolyzing the laminarin present in the macroalage. Fermentation of the algal hydrolysate yielded only small amount of ethanol due to lack of other pre-treatment methods, however, it was observed that higher ethanol was produced in saccharification treatments using a combination of cellulase and laminarinase which implies a possible synergistic effect between the two enzymes.

  6. Control of biofouling by xanthine oxidase on seawater reverse osmosis membranes from a desalination plant: enzyme production and screening of bacterial isolates from the full-scale plant.

    Science.gov (United States)

    Nagaraj, V; Skillman, L; Li, D; Xie, Z; Ho, G

    2017-07-01

    Control of biofouling on seawater reverse osmosis (SWRO) membranes is a major challenge as treatments can be expensive, damage the membrane material and often biocides do not remove the polymers in which bacteria are embedded. Biological control has been largely ignored for biofouling control. The objective of this study was to demonstrate the effectiveness of xanthine oxidase enzyme against complex fouling communities and then identify naturally occurring bacterial strains that produce the free radical generating enzyme. Initially, 64 bacterial strains were isolated from different locations of the Perth Seawater Desalination Plant. In our preceding study, 25/64 isolates were selected from the culture collection as models for biofouling studies, based on their prevalence in comparison to the genomic bacterial community. In this study, screening of these model strains was performed using a nitroblue tetrazolium assay in the presence of hypoxanthine as substrate. Enzyme activity was measured by absorbance. Nine of 25 strains tested positive for xanthine oxidase production, of which Exiguobacterium from sand filters and Microbacterium from RO membranes exhibited significant levels of enzyme production. Other genera that produced xanthine oxidase were Marinomonas, Pseudomonas, Bacillus, Pseudoalteromonas and Staphylococcus. Strain variations were observed between members of the genera Microbacterium and Bacillus. Xanthine oxidase, an oxidoreductase enzyme that generates reactive oxygen species, is endogenously produced by many bacterial species. In this study, production of the enzyme by bacterial isolates from a full-scale desalination plant was investigated for potential use as biological control of membrane fouling in seawater desalination. We have previously demonstrated that free radicals generated by a commercially available xanthine oxidase in the presence of a hypoxanthine substrate, effectively dispersed biofilm polysaccharides on industrially fouled membranes

  7. Epicuticular wax on cherry laurel (Prunus laurocerasus) leaves does not constitute the cuticular transpiration barrier.

    Science.gov (United States)

    Zeisler, Viktoria; Schreiber, Lukas

    2016-01-01

    Epicuticular wax of cherry laurel does not contribute to the formation of the cuticular transpiration barrier, which must be established by intracuticular wax. Barrier properties of cuticles are established by cuticular wax deposited on the outer surface of the cuticle (epicuticular wax) and in the cutin polymer (intracuticular wax). It is still an open question to what extent epi- and/or intracuticular waxes contribute to the formation of the transpiration barrier. Epicuticular wax was mechanically removed from the surfaces of isolated cuticles and intact leaf disks of cherry laurel (Prunus laurocerasus L.) by stripping with different polymers (collodion, cellulose acetate and gum arabic). Scanning electron microscopy showed that two consecutive treatments with all three polymers were sufficient to completely remove epicuticular wax since wax platelets disappeared and cuticle surfaces appeared smooth. Waxes in consecutive polymer strips and wax remaining in the cuticle after treatment with the polymers were determined by gas chromatography. This confirmed that two treatments of the polymers were sufficient for selectively removing epicuticular wax. Water permeability of isolated cuticles and cuticles covering intact leaf disks was measured using (3)H-labelled water before and after selectively removing epicuticular wax. Cellulose acetate and its solvent acetone led to a significant increase of cuticular permeability, indicating that the organic solvent acetone affected the cuticular transpiration barrier. However, permeability did not change after two subsequent treatments with collodion and gum arabic or after treatment with the corresponding solvents (diethyl ether:ethanol or water). Thus, in the case of P. laurocerasus the epicuticular wax does not significantly contribute to the formation of the cuticular transpiration barrier, which evidently must be established by the intracuticular wax.

  8. 'In-Crystallo' Capture of a Michaelis Complex And Product Binding Modes of a Bacterial Phosphotriesterase

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, C.J.; Foo, J.-L.; Kim, H.-K.; Carr, P.D.; Liu, J.-W.; Salem, G.; Ollis, D.L.

    2009-05-18

    The mechanism by which the binuclear metallophosphotriesterases (PTEs, E.C. 3.1.8.1) catalyse substrate hydrolysis has been extensively studied. The {mu}-hydroxo bridge between the metal ions has been proposed to be the initiating nucleophile in the hydrolytic reaction. In contrast, analysis of some biomimetic systems has indicated that {mu}-hydroxo bridges are often not themselves nucleophiles, but act as general bases for freely exchangeable nucleophilic water molecules. Herein, we present crystallographic analyses of a bacterial PTE from Agrobacterium radiobacter, OpdA, capturing the enzyme-substrate complex during hydrolysis. This model of the Michaelis complex suggests the alignment of the substrate will favor attack from a solvent molecule terminally coordinated to the {alpha}-metal ion. The bridging of both metal ions by the product, without disruption of the {mu}-hydroxo bridge, is also consistent with nucleophilic attack occurring from the terminal position. When phosphodiesters are soaked into crystals of OpdA, they coordinate bidentately to the {beta}-metal ion, displacing the {mu}-hydroxo bridge. Thus, alternative product-binding modes exist for the PTEs, and it is the bridging mode that appears to result from phosphotriester hydrolysis. Kinetic analysis of the PTE and promiscuous phosphodiesterase activities confirms that the presence of a {mu}-hydroxo bridge during phosphotriester hydrolysis is correlated with a lower pK{sub a} for the nucleophile, consistent with a general base function during catalysis.

  9. Cellular adverse actions of dibromoacetonitrile, a by-product in water bacterial control, at sublethal levels in rat thymocytes.

    Science.gov (United States)

    Kishida, Takumi; Akiyoshi, Kenji; Erdenedalai, Erdenebat; Enhetomuru, Anu; Imai, Shoji; Oyama, Yasuo

    2018-09-01

    The aim of this study was to investigate the effects of dibromoacetonitrile (DBAN), a by-product in water bacterial control, at sublethal concentrations on rat thymocytes, by using a cytometric technique with appropriate fluorescent dyes. By using this method, the possibility that DBAN induces cellular actions related to oxidative stress was assessed. DBAN reduced the content of cellular nonprotein thiols under Zn 2+ -free conditions. It elevated the intracellular level of Zn 2+ , being independent from external Zn 2+ . DBAN increased cell vulnerability to the cytotoxic action of hydrogen peroxide. These actions of DBAN were likely related to oxidative stress. DBAN is formed by the reaction of bromides and chlorinated oxidants during water disinfection. Hydrolysis of 2,2-dibromo-3-nitrilopropionamide, an antimicrobial used in hydraulic fracturing fluids for production of shale gas and oil, produces DBAN. Therefore, the concern regarding the levels of DBAN in industrial water systems is necessary to avoid the environmental risk to humans and wild mammals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Production of polyhydroxyalkanoates (PHA) by bacterial consortium from excess sludge fermentation liquid at laboratory and pilot scales.

    Science.gov (United States)

    Jia, Qianqian; Xiong, Huilei; Wang, Hui; Shi, Hanchang; Sheng, Xinying; Sun, Run; Chen, Guoqiang

    2014-11-01

    The generation of polyhydroxyalkanoates (PHA) from excess sludge fermentation liquid (SFL) was studied at lab and pilot scale. A PHA-accumulated bacterial consortium (S-150) was isolated from activated sludge using simulated SFL (S-SFL) contained high concentration volatile fatty acids (VFA) and nitrogen. The maximal PHA content accounted for 59.18% in S-SFL and dropped to 23.47% in actual SFL (L-SFL) of the dry cell weight (DCW) at lab scale. The pilot-scale integrated system comprised an anaerobic fermentation reactor (AFR), a ceramic membrane system (CMS) and a PHA production bio-reactor (PHAR). The PHA content from pilot-scale SFL (P-SFL) finally reached to 59.47% DCW with the maximal PHA yield coefficient (YP/S) of 0.17 g PHA/g COD. The results indicated that VFA-containing SFL was suitable for PHA production. The adverse impact of excess nitrogen and non-VFAs in SFL might be eliminated by pilot-scale domestication, which might resulted in community structure optimization and substrate selective ability improvement of S-150. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. A Clostridium difficile Cell Wall Glycopolymer Locus Influences Bacterial Shape, Polysaccharide Production and Virulence.

    Directory of Open Access Journals (Sweden)

    Michele Chu

    2016-10-01

    Full Text Available Clostridium difficile is a diarrheagenic pathogen associated with significant mortality and morbidity. While its glucosylating toxins are primary virulence determinants, there is increasing appreciation of important roles for non-toxin factors in C. difficile pathogenesis. Cell wall glycopolymers (CWGs influence the virulence of various pathogens. Five C. difficile CWGs, including PSII, have been structurally characterized, but their biosynthesis and significance in C. difficile infection is unknown. We explored the contribution of a conserved CWG locus to C. difficile cell-surface integrity and virulence. Attempts at disrupting multiple genes in the locus, including one encoding a predicted CWG exporter mviN, were unsuccessful, suggesting essentiality of the respective gene products. However, antisense RNA-mediated mviN downregulation resulted in slight morphology defects, retarded growth, and decreased surface PSII deposition. Two other genes, lcpA and lcpB, with putative roles in CWG anchoring, could be disrupted by insertional inactivation. lcpA- and lcpB- mutants had distinct phenotypes, implying non-redundant roles for the respective proteins. The lcpB- mutant was defective in surface PSII deposition and shedding, and exhibited a remodeled cell surface characterized by elongated and helical morphology, aberrantly-localized cell septae, and an altered surface-anchored protein profile. Both lcpA- and lcpB- strains also displayed heightened virulence in a hamster model of C. difficile disease. We propose that gene products of the C. difficile CWG locus are essential, that they direct the production/assembly of key antigenic surface polysaccharides, and thereby have complex roles in virulence.

  12. Commercialization of bacterial cell factories for the sustainable production of polyhydroxyalkanoate thermoplastics: progress and prospects.

    Science.gov (United States)

    Kumar, Abhishek; Srivastava, Janmejai K; Mallick, Nirupama; Singh, Akhilesh K

    2015-01-01

    Ubiquitous conventional plastics, generally manufactured from finite, nonsustainable fossil fuels are non-biodegradable wonder entities but their ill effect on Mother Nature has subsequently raised major environmental concerns like their safe disposal, solid waste management and several potential hazards. Such concerns have fuelled initiatives for research globally towards development of sustainable and eco-friendly bioplastics. The new generation of plastics called 'bioplastics' are polymers of long chain of repeating monomer units that are classified as photodegradable, semi-biodegradable, chemically synthesized and polyhydroxyalkanoates (PHAs). The commonly emerged novel bioplastics are polyesters of hydroxyalkanoates (HAs) called PHAs, which are lipoidic storage materials found in the cytosol of vast and diverse forms of bacteria. Among 150 different PHAs known so far, poly- 3-hydroxybutyrate is the most common and comprehensively characterized PHA. Interestingly, PHAs are only completely biodegradable plastics with material properties comparable to conventional plastics that can be achieved by regulating the co-monomers incorporation into PHAs backbone. PHA bioplastics are exploited in the form of user-friendly goods viz. films, absorbable sutures, bone plates, drug carriers, etc. Besides advantages, such useful entity(s) has major shortcomings as well like high production cost compared to conventional plastics. Precisely, in PHAs production, about fifty percent of the overall price is due to the carbon substrates. Consequently, exploring novel cost-effective substrates is a major compulsion for successful commercialization of this bioplastic, which is anticipated to reduce the cost of production as a result of advancing and intensifying research work. This review presents an insight and patent developments in the field of PHAs bioplastics.

  13. Characterization and crop production efficiency of diazotrophic bacterial isolates from coastal saline soils.

    Science.gov (United States)

    Barua, Shilajit; Tripathi, Sudipta; Chakraborty, Ashis; Ghosh, Sagarmoy; Chakrabarti, Kalyan

    2012-01-20

    Use of eco-friendly area specific salt tolerant bioinoculants is better alternatives to chemical fertilizer for sustainable agriculture in coastal saline soils. We isolated diverse groups of diazotrophic bacteria from coastal saline soils of different forest and agricultural lands in the Sundarbans, West Bengal, India, to study their effect on crop productivity in saline soils. Phenotypic, biochemical and molecular identifications of the isolates were performed. The isolates produced indole acetic acid, phosphatase, and solubilized insoluble phosphates. Sequence analysis of 16S rDNA identified the SUND_BDU1 strain as Agrobacterium and the strains SUND_LM2, Can4 and Can6 belonging to the genus Bacillus. The ARA activity, dinitrogen fixation and presence of nifH genes indicated they were diazotrophs. Field trials with these strains as bioinoculants were carried out during 2007-2009, with rice during August-December followed by Lady's finger during April-June. Microplots, amended with FYM inoculated with four bioinoculants individually were compared against sole FYM (5 t ha(-1)) and a sole chemical fertilizer (60:30:30 kg ha(-1) NPK) treated plot. The strain Can6 was by far the best performer in respect of yield attributes and productivity of studied crops. Copyright © 2011 Elsevier GmbH. All rights reserved.

  14. Saponin, an inhibitory agent of carbon dioxide production by white cells : its use in the microbiologic examination of blood components in an automated bacterial culture system

    NARCIS (Netherlands)

    van Doorne, Hans; van der Tuuk Adriani, W.P A; van der Ven, L.I; Bosch, E.H; de Natris, T; Smit Sibinga, C.Th.

    1998-01-01

    BACKGROUND: Blood components with a white cell count >100 x 10(9) per L may cause false-positive results when the BacT/Alert system is used for the microbiologic examination. The effects of different concentrations of saponin on bacterial growth and on carbon dioxide production by blood fractions

  15. Transient changes in milk production efficiency and bacterial community composition resulting from near-total exchange of ruminal contents between high- and low-efficiency Holstein cows

    Science.gov (United States)

    The objectives of this study were to determine if milk production efficiency (MPE) is altered by near-total exchange of ruminal contents between high- (HE) and low-MPE (LE) cows and to characterize ruminal bacterial community composition (BCC) prior to exchange and over time post-exchange. Three pai...

  16. Wax ester profiling of seed oil by nano-electrospray ionization tandem mass spectrometry

    Science.gov (United States)

    2013-01-01

    Background Wax esters are highly hydrophobic neutral lipids that are major constituents of the cutin and suberin layer. Moreover they have favorable properties as a commodity for industrial applications. Through transgenic expression of wax ester biosynthetic genes in oilseed crops, it is possible to achieve high level accumulation of defined wax ester compositions within the seed oil to provide a sustainable source for such high value lipids. The fatty alcohol moiety of the wax esters is formed from plant-endogenous acyl-CoAs by the action of fatty acyl reductases (FAR). In a second step the fatty alcohol is condensed with acyl-CoA by a wax synthase (WS) to form a wax ester. In order to evaluate the specificity of wax ester biosynthesis, analytical methods are needed that provide detailed wax ester profiles from complex lipid extracts. Results We present a direct infusion ESI-tandem MS method that allows the semi-quantitative determination of wax ester compositions from complex lipid mixtures covering 784 even chain molecular species. The definition of calibration prototype groups that combine wax esters according to their fragmentation behavior enables fast quantitative analysis by applying multiple reaction monitoring. This provides a tool to analyze wax layer composition or determine whether seeds accumulate a desired wax ester profile. Besides the profiling method, we provide general information on wax ester analysis by the systematic definition of wax ester prototypes according to their collision-induced dissociation spectra. We applied the developed method for wax ester profiling of the well characterized jojoba seed oil and compared the profile with wax ester-accumulating Arabidopsis thaliana expressing the wax ester biosynthetic genes MaFAR and ScWS. Conclusions We developed a fast profiling method for wax ester analysis on the molecular species level. This method is suitable to screen large numbers of transgenic plants as well as other wax ester samples

  17. Isolation of non-sulphur photosynthetic bacterial strains efficient in hydrogen production at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P.; Srivastava, S.C. (Banaras Hindu Univ., Varanasi (IN). Centre of Advanced Study in Botany)

    1991-01-01

    Four strains of non-sulphur photosynthetic bacteria were isolated from root zone associations of aquatic plants like Azolla, Salvinia and Eichhornia, as well as the deep-water rice. Based on the gross cell morphology and pigmentation, the isolates resembled Rhodopseudomonas sp. and have been designated as BHU strains 1 to 4, respectively. When subjected to elevated temperature (from 33-45{sup o}C), substantial growth/hydrogen production could be observed only in strains 1 and 4. Strains 2 and 3 on the other hand, showed diminished growth and negligible hydrogen photoproduction. The BHU strains 1 and 4 have been selected as the most active (thermostable) hydrogen producing strains of local origin as far as the Indian tropical climate is concerned. (author).

  18. Comparison of some indigenous bacterial strains of pseudomonas ssp. for production of biosurfactants

    International Nuclear Information System (INIS)

    Sahafeeq, M.; Kokub, D.; Khalid, Z.M.; Malik, K.A.

    1991-01-01

    Some indigenous pseudomonas spp. were found to have the ability of emulsification, lowering the surface and interfacial tensions, and formation of high reciprocal CMCs. Six strains of Pseudomonas spp were compared for biosurfactant production grown on hexadecane. Supernatant from whole culture broth of these strains could lower surface tension from 65 mN/m to 28-32 nM/m, interfacial tension from 40 nM/m to 1-3 mN/m and had high reciprocal CMCs. When compared for emulsification ability by the culture broth of these strains, the emulsification index (E24) was found to range between 60-65. Biosurfactant containing culture broth of some strains could retain the property up to 80 C, pH of 13 and sodium chloride concentration for 17% which indicates their possible role in some depleted oil well. (author)

  19. Replication of specifically microstructured surfaces in A356-alloy via lost wax investment casting

    International Nuclear Information System (INIS)

    Ivanov, Todor; Bührig-Polaczek, Andreas; Vroomen, Uwe; Hartmann, Claudia; Holtkamp, Jens; Gillner, Arnold; Bobzin, Kirsten; Bagcivan, Nazlim; Theiss, Sebastian

    2011-01-01

    A common way of realizing microstructural features on metallic surfaces is to generate the designated pattern on each single part by means of microstructuring technologies such as e.g. laser ablation, electric discharge machining or micromilling. The disadvantage of these process chains is the limited productivity due to the additional processing of each part. The approach of this work is to replicate microstructured surfaces from a master pattern via lost wax investment casting in order to reach a higher productivity. We show that microholes of different sizes ( 15–22 µm at depths of 6–14 µm) can be replicated in AlSi7Mg-alloy from a laser-structured master pattern via investment casting. However, some loss of molding accuracy during the multi-stage molding process occurs. Approximately 50% of the original microfeature's heights are lost during the wax injection step. In the following process step of manufacturing a gypsum-bonded mold, a further loss in the surface quality of the microfeatures can be observed. In the final process step of casting the aluminum melt, the microfeatures are filled without any loss of molding accuracy and replicate the surface quality of the gypsum mold. The contact angle measurements of ultrapure water on the cast surfaces show a decrease in wettability on the microstructured regions (75°) compared to the unstructured region (60°)

  20. Studies on Hydrotreating Process of Microcrystalline Wax Produced from Marine Belayim Crude Oil

    International Nuclear Information System (INIS)

    EI Karashi, S.; Marawan, H.

    2004-01-01

    Abstract Microcrystalline wax was produced from solvent dewaxing process of vacuum residue raffinate produced from Marine Belayim origin. The untreated microcrystalline wax contains trace amounts of sulfur, oxygen, nitrogen and organometallic compounds as well as heavy aromatics which affect the properties of wax applications in pharmaceutical and technical fields . Microcrystalline wax hydrotreating process was studied using digital controlled unit and Ni O-MoO 3 / Al 2 O 3 catalyst, where operating parameters that controlled the efficiency of the hydrotreated wax were studied separately at different values including reactor temperature, reactor pressure, liquid hourly space velocity and hydrogen to hydrocarbon ratio . Hydrotreated microcrystalline wax at operating conditions (temperature 300 degree C, pressure 73 kg/cm 2 , LHS V 0.52 h-l and H 2 /HC ratio 266.6 Nm 3 /m 3 ) has the best quality to be used as food grade wax

  1. Alginato bacteriano: aspectos tecnológicos, características e produção Bacterial alginate: technological aspects, characteristics and production

    Directory of Open Access Journals (Sweden)

    Crispin Humberto Garcia-Cruz

    2008-01-01

    Full Text Available Alginate is a biopolymer used for a variety of industrial applications, for example, in the textiles, cosmetics, foods, agricultural and biotechnological industries. This biopolymer is traditionally extracted from some brown seaweeds (Phaeophyceae and can be produced by bacteria isolated from soil, as Azotobacter vinelandii, like capsular polysaccharide using glucose, sucrose, among others as carbon sources. The main difference between the alginate of seaweed and the bacterial ones, is the biggest degree of acetylation of this last one, with great influence in the gel force. These chemical characteristics and production of bacterial alginate are presented in this work.

  2. The polyketide components of waxes and the Cer-cqu gene cluster encoding a novel polyketide synthase, the β-diketone synthase, DKS

    DEFF Research Database (Denmark)

    von Wettstein, Penny

    2017-01-01

    The primary function of the outermost, lipophilic layer of plant aerial surfaces, called the cuticle, is preventing non-stomatal water loss. Its exterior surface is often decorated with wax crystals, imparting a blue-grey color. Identification of the barley Cer-c, -q and -u genes forming the 101 kb...... Cer-cqu gene cluster encoding a novel polyketide synthase-the β-diketone synthase (DKS), a lipase/carboxyl transferase, and a P450 hydroxylase, respectively, establishes a new, major pathway for the synthesis of plant waxes. The major product is a β-diketone (14,16-hentriacontane) aliphatic that forms...

  3. Improvement of vitamin B-6 production by gamma radiation in bacterial isolates from soil sample

    International Nuclear Information System (INIS)

    Trongpanich, Yanee; Anutrakunchai, Chitchanok; Piadang, Nattayana

    2006-09-01

    A vitamin B-6 producing bacterium, Rhizobium sp. 6.1C1 was isolated from soil and produced vitamin B-6 (mainly pyridoxamine) 0.27 mg per liter. Rhizobium sp. 6.1C1 is mesophile bacterium which was not able to grow at over 4 0C. The objective of this study was to improve vitamin B-6 production in high temperature by gamma radiation. The result showed that 677 mutant isolates which were obtained from irradiation dose 0.8 and 1 kGy, were able to grow at 5 0C. Only 4 isolates (08-361, 10-3, 10-94 and 10-98) showed high amount of vitamin B-6 per mg protein. From the results of optimum temperature and initial pH of medium showed high amount of vitamin B-6 per mg protein. From the results of optimum temperature and initial pH of medium showed that isolate 08-361 showed higher amount of vitamin b-6 than wild type. However, this value of vitamin B-6 from this mutant was lower than that when screening. Forms of produced vitamin B-6 from mutant were identified by HPLC. The result showed produced vitamin B-6 were PM and PMP, similar with wild type. Effect of gamma radiation stability of mutant is further study.

  4. Radiotherapic Valuation of Paraffin Wax for Patients with Oral Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Na, Kyung Su; Seo, Seuk Jin; Lee, Je Hee; Yoo, Sook Heun [Dept. of Radiation Oncology, Seoul National University Hosdital, Seoul (Korea, Republic of)

    2011-03-15

    This study is designed to investigate radiotherapic valuation of Paraffin Wax, which is newly formed for this study and generally utilized in dentistry, and Mouth Piece and Putty impression, which are commonly used in radiotherapy, for oral cavity as a compensator. Each compensator was formed by 10 x 10 x 1 cm and measured radiation dose attenuation ratio with reference of water phantom which is made of tissue-equivalent materials. Two patients with oral cancer underwent DRR (Digitally Reconstructed Radiogrph) of Offline Review Program of Aria System and Portal vision for 5 times for each material to evaluate reproducibility by each filling materials. Moreover, MU (monitor unit) changes by dose absorption were considered in the case of inevitable implication of an filling materials in the range for radiotherapy. Radiation dose attenuation ratios were shown -0.7{approx}+3.7% for Mouth Piece, +0.21{approx}+0.39% for Paraffin Wax and -2.71{approx}-1.76% for Putty impression. Error ranges of reproducibility of positions were measured {+-}3 mm for Mouth Piece, {+-}2 mm for Paraffin Wax and {+-}2 mm for Putty impression. Difference of prescription MU from dose absorption with an filling material increased +7.8% (250 MU) in Putty impression and -0.9% (230 MU) in Paraffin Wax as converted into a percentage from the standard phantom, Water 232 MU. Dose reduction of boundary between cavity and tissue was observed for Mouth Piece. Mouth Piece also had low reproducibility of positions as it had no reflection of anatomy of oral cavity even though it was a proper material to separate Maxilla and Mandible during therapy. On the other hand, Putty impression was a suitable material to correctly re-position oral cavity as before. However, it risked normal tissues getting unnecessary over irradiation and it caused radiation dose decrease by -2.5% for 1cm volume in comparison of it of water phantom. Dose reduction in Paraffin Wax, Fat Tissue-Equivalent Material, was smaller than other

  5. Radiotherapic Valuation of Paraffin Wax for Patients with Oral Cancer

    International Nuclear Information System (INIS)

    Na, Kyung Su; Seo, Seuk Jin; Lee, Je Hee; Yoo, Sook Heun

    2011-01-01

    This study is designed to investigate radiotherapic valuation of Paraffin Wax, which is newly formed for this study and generally utilized in dentistry, and Mouth Piece and Putty impression, which are commonly used in radiotherapy, for oral cavity as a compensator. Each compensator was formed by 10 x 10 x 1 cm and measured radiation dose attenuation ratio with reference of water phantom which is made of tissue-equivalent materials. Two patients with oral cancer underwent DRR (Digitally Reconstructed Radiogrph) of Offline Review Program of Aria System and Portal vision for 5 times for each material to evaluate reproducibility by each filling materials. Moreover, MU (monitor unit) changes by dose absorption were considered in the case of inevitable implication of an filling materials in the range for radiotherapy. Radiation dose attenuation ratios were shown -0.7∼+3.7% for Mouth Piece, +0.21∼+0.39% for Paraffin Wax and -2.71∼-1.76% for Putty impression. Error ranges of reproducibility of positions were measured ±3 mm for Mouth Piece, ±2 mm for Paraffin Wax and ±2 mm for Putty impression. Difference of prescription MU from dose absorption with an filling material increased +7.8% (250 MU) in Putty impression and -0.9% (230 MU) in Paraffin Wax as converted into a percentage from the standard phantom, Water 232 MU. Dose reduction of boundary between cavity and tissue was observed for Mouth Piece. Mouth Piece also had low reproducibility of positions as it had no reflection of anatomy of oral cavity even though it was a proper material to separate Maxilla and Mandible during therapy. On the other hand, Putty impression was a suitable material to correctly re-position oral cavity as before. However, it risked normal tissues getting unnecessary over irradiation and it caused radiation dose decrease by -2.5% for 1cm volume in comparison of it of water phantom. Dose reduction in Paraffin Wax, Fat Tissue-Equivalent Material, was smaller than other impressions and

  6. Mechanical properties of carving wax with various Ca-bentolite filter composition

    Directory of Open Access Journals (Sweden)

    Widjijono Widjijono

    2009-09-01

    Full Text Available Background: The carving wax is used as a medium in dental anatomy study. This wax composes of many waxes and sometimes a filler is added. Carving wax is not sold in Indonesian market. Whereas the gradients of carving wax such as beeswax, paraffin and bentonite are abundant in Indonesia. Based on that fact, to make high quality and standard,the exact composition if this carving wax should be known. Purpose: The aim of this study was to investigate the effect of carving wax composition with Ca-bentonite filler on the melting point, hardness, and thermal expansion. Methods: Five carving wax compositions were made with paraffin, Ca-bentonite, carnauba wax, and beeswax in ratio (% weight: 50:20:25:5 (KI, 55:15:25:5 (KII, 60:10:25:5 (KIII, 65:5:25:5 (KIV, 70:0:25:5(KV. All components were melted, then poured into the melting point, hardness, and thermal expansion moulds (n = 5. Three carving wax properties were tested: melting point by melting point apparatus; hardness by penetrometer; thermal expansion by digital sliding caliper. The data were analyzed statistically using One-Way ANOVA and LSD0.05. Result: The Ca-bentonite addition influenced the melting point and thermal expansion of carving wax with significant differences between KI and other groups (p < 0.05. Ca-bentonite addition influenced the carving wax hardness and the mean differences among the groups were significant (p < 0.05. Conclusion: Ca-bentonite filler addition on the composition of carving wax influenced the physical and mechanical properties. The carving wax with high Ca-bentonite concentration had high melting point and hardness, but low thermal expansion.

  7. Total volatile fatty acids and bacterial production rates as affected by rations containing untreated or ammonia (urea) treated rice straw in croos-bred cattle

    International Nuclear Information System (INIS)

    Puri, J.P.; Gupta, B.N.

    1990-01-01

    An experiment was conducted to study the effect of feeding ammoniated rice straw on ruminal total volatile fatty acid (TVFA) and bacterial production rates. Twelve karan swiss, male, rumen fistulated calves (2-2.5 yrs) were divided in three equal groups. Animals were offered rice straw either untreated (A) or 4 per cent urea+40 per cent moisture treated and ensiled for 30 days (B) or 5 per cent urea+30 per cent moisture treated and ensiled for 30 days (C). Protein requirements were met through concentrate mixture. Levels of NH 3 -N and TCA-precipitable-N in strained rumen liquor (SRL) were significantly higher (20.34±0.022, 63.26±0.81 (B), 20.78±0.41, 64.98±0.87 (C) (mg/100 ml SRL) in groups fed ammoniated ±0.31, 45.94±1.91 mg/100 ml S RL), respectively. The bacterial production rates in the rumen (g/day) were significantly higher in groups B and C as compared to group A. TVFA concentrations (mmole/100 ml SRL ) and TVFA production rates (mmole/d) were also significantly higher in groups B and C as compared to group A. The bacterial production rates were significantly co-related with TVFA, NH 3 -N, TCA precipitable-N concentration in the rumen and ATP production. Multiple regression equations relating bacterial production rates with (i)NH 3 -N and TVFA concentration in the rumen, (ii)NH 3 -N and TVFA production rates and (iii)NH 3 -N and ATP produced were also developed. (author). 18 refs., 2 tabs

  8. Reduced Silver Nanoparticle Phytotoxicity in Crambe abyssinica with Enhanced Glutathione Production by Overexpressing Bacterial γ-Glutamylcysteine Synthase.

    Science.gov (United States)

    Ma, Chuanxin; Chhikara, Sudesh; Minocha, Rakesh; Long, Stephanie; Musante, Craig; White, Jason C; Xing, Baoshan; Dhankher, Om Parkash

    2015-08-18

    Silver nanoparticles (Ag NPs) are widely used in consumer products, and their release has raised serious concerns about the risk of their exposure to the environment and to human health. However, biochemical mechanisms by which plants counteract NP toxicity are largely unknown. We have previously engineered Crambe abyssinica plants expressing the bacterial γ-glutamylecysteine synthase (γ-ECS) for enhancing glutathione (GSH) levels. In this study, we investigated if enhanced levels of GSH and its derivatives can protect plants from Ag NPs and AgNO3 (Ag(+) ions). Our results showed that transgenic lines, when exposed to Ag NPs and Ag(+) ions, were significantly more tolerant, attaining a 28%-46% higher biomass and 34-49% more chlorophyll content, as well as maintaining 35-46% higher transpiration rates as compared to those of wild type (WT) plants. Transgenic γ-ECS lines showed 2-6-fold Ag accumulation in shoot tissue and slightly lower or no difference in root tissue relative to levels in WT plants. The levels of malondialdehyde (MDA) in γ-ECS lines were also 27.3-32.5% lower than those in WT Crambe. These results indicate that GSH and related peptides protect plants from Ag nanotoxicity. To our knowledge, this is the first direct report of Ag NP detoxification by GSH in transgenic plants, and these results will be highly useful in developing strategies to counteract the phytotoxicty of metal-based nanoparticles in crop plants.

  9. Bacterial community structure and variation in a full-scale seawater desalination plant for drinking water production

    KAUST Repository

    Belila, Abdelaziz

    2016-02-18

    Microbial processes inevitably play a role in membrane-based desalination plants, mainly recognized as membrane biofouling. We assessed the bacterial community structure and diversity during different treatment steps in a full-scale seawater desalination plant producing 40,000 m3/d of drinking water. Water samples were taken over the full treatment train consisting of chlorination, spruce media and cartridge filters, de-chlorination, first and second pass reverse osmosis (RO) membranes and final chlorine dosage for drinking water distribution. The water samples were analyzed for water quality parameters (total bacterial cell number, total organic carbon, conductivity, pH, etc.) and microbial community composition by 16S rRNA gene pyrosequencing. The planktonic microbial community was dominated by Proteobacteria (48.6%) followed by Bacteroidetes (15%), Firmicutes (9.3%) and Cyanobacteria (4.9%). During the pretreatment step, the spruce media filter did not impact the bacterial community composition dominated by Proteobacteria. In contrast, the RO and final chlorination treatment steps reduced the Proteobacterial relative abundance in the produced water where Firmicutes constituted the most dominant bacterial group. Shannon and Chao1 diversity indices showed that bacterial species richness and diversity decreased during the seawater desalination process. The two-stage RO filtration strongly reduced the water conductivity (>99%), TOC concentration (98.5%) and total bacterial cell number (>99%), albeit some bacterial DNA was found in the water after RO filtration. About 0.25% of the total bacterial operational taxonomic units (OTUs) were present in all stages of the desalination plant: the seawater, the RO permeates and the chlorinated drinking water, suggesting that these bacterial strains can survive in different environments such as high/low salt concentration and with/without residual disinfectant. These bacterial strains were not caused by contamination during

  10. Methods of studying aging and stabilization of spray-congealed solid dispersions with carnauba wax. 1. Microcalorimetric investigation.

    Science.gov (United States)

    Emås, M; Nyqvist, H

    2000-03-20

    Rapidly cooled materials are often unstable as a result of changes in their physical properties due to imperfect crystallization. In the process of spray-congealing, melted material is atomized into droplets which very quickly solidify. This increases the possibility of the material crystallizing in different metastable forms. In this study it is shown that isothermal microcalorimetry can be used to observe the change in the thermodynamic state of spray-congealed carnauba wax during storage. In order to accelerate the thermodynamic change in the spray-congealed wax, three annealing procedures have been developed and compared using isothermal microcalorimetry. By means of annealing, a spray-congealed product closer to a thermodynamically stable state has been achieved.

  11. Long-term organic-inorganic fertilization ensures great soil productivity and bacterial diversity after natural-to-agricultural ecosystem conversion.

    Science.gov (United States)

    Xun, Weibing; Xu, Zhihui; Li, Wei; Ren, Yi; Huang, Ting; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-09-01

    Natural ecosystems comprise the planet's wild plant and animal resources, but large tracts of land have been converted to agroecosystems to support the demand for agricultural products. This conversion limits the number of plant species and decreases the soil biological diversity. Here we used high-throughput 16S rRNA gene sequencing to evaluate the responses of soil bacterial communities in long-term converted and fertilized red soils (a type of Ferralic Cambisol). We observed that soil bacterial diversity was strongly affected by different types of fertilization management. Oligotrophic bacterial taxa demonstrated large relative abundances in chemically fertilized soil, whereas copiotrophic bacterial taxa were found in large relative abundances in organically fertilized and fallow management soils. Only organic-inorganic fertilization exhibited the same local taxonomic and phylogenetic diversity as that of a natural ecosystem. However, the independent use of organic or inorganic fertilizer reduced local taxonomic and phylogenetic diversity and caused biotic homogenization. This study demonstrated that the homogenization of bacterial communities caused by natural-to-agricultural ecosystem conversion can be mitigated by employing rational organic-inorganic fertilization management.

  12. Production of glycolipidic bio surfactants by environment bacteria: diversity and physiological part; Production de biosurfactants glycolipidiques par les bacteries de l`environnement: diversite et role physiologique

    Energy Technology Data Exchange (ETDEWEB)

    Arino, S

    1996-10-09

    About a hundred bacterial strains, isolated from soils, polluted or not by hydrocarbons, were tested for their capacity to excrete glycosides. The biggest productions were obtained for a soluble carbon source (glycerol) in a culture medium limited in the nitrogen source. In these conditions, 18 g/l of rhamnose lipids were produced by train Pseudomonas aeruginosa GL1 in a 200 h culture. Pseudomonas aeruginosa GL1, Cellulomonas celulans SA43 and Rhodococcus erythropolis DSM 43060 were studied in detail. The bio-surfactants produced were identified respectively as rhamnose lipids, oligosaccharide lipids and trehalose lipids, using various original analytical methods. Sugars and fatty acids composing these glycolipids had been shown to be usual components of the outer part of the cell wall in these microbial species. Moreover, cell hydrophobicity of the producing bacteria varied in time during culture. These results showed that both the cell wall and the extracellular glycolipids take part in the process of hydrocarbon uptake in the polluted environments. As other bacteria of the same species from different origins present the same characteristics, it may be concluded that glycolipid excretion does not constitute a specific response for hydrocarbon assimilation. In fact, a more general physiological role of glycolipids, concerning modifications of hydrophobic interfaces between the producing bacteria and their surrounding environment, could explain the production of glycolipids, and could also be utilized in hydrocarbon uptake. (author)

  13. Effect of L-glucose and D-tagatose on bacterial growth in media and a cooked cured ham product.

    Science.gov (United States)

    Bautista, D A; Pegg, R B; Shand, P J

    2000-01-01

    Cured meats such as ham can undergo premature spoilage on account of the proliferation of lactic acid bacteria. This spoilage is generally evident from a milkiness in the purge of vacuum-packaged sliced ham. Although cured, most hams are at more risk of spoilage than other types of processed meat products because they contain considerably higher concentrations of carbohydrates, approximately 2 to 7%, usually in the form of dextrose and corn syrup solids. Unfortunately, the meat industry is restricted with respect to the choice of preservatives and bactericidal agents. An alternative approach from these chemical compounds would be to use novel carbohydrate sources that are unrecognizable to spoilage bacteria. L-Glucose and D-tagatose are two such potential sugars, and in a series of tests in vitro, the ability of bacteria to utilize each as an energy source was compared to that of D-glucose. Results showed that both L-glucose and D-tagatose are not easily catabolized by a variety of lactic bacteria and not at all by pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, and Yersinia enterocolitica. In a separate study, D-glucose, L-glucose, and D-tagatose were added to a chopped and formed ham formulation and the rate of bacterial growth was monitored. Analysis of data by a general linear model revealed that the growth rates of total aerobic and lactic acid bacteria were significantly (P D-tagatose than those containing L- or D-glucose. Levels of Enterobacteriaceae were initially low and these bacteria did not significantly (P D-tagatose at 10 degrees C was extended by 7 to 10 days. These results indicate that D-tagatose could deter the growth of microorganisms and inhibit the rate of spoilage in a meat product containing carbohydrates.

  14. Study of Plant Waxes Using Low Temperature Method for ESEM

    Czech Academy of Sciences Publication Activity Database

    Neděla, Vilém; Tihlaříková, Eva; Schiebertová, P.; Zajícová, I.; Schwarzerová, K.

    2016-01-01

    Roč. 22, S3 (2016), s. 1180-1181 ISSN 1431-9276 R&D Projects: GA ČR(CZ) GA14-22777S; GA MŠk ED0017/01/01 Grant - others:GA MŠk(CZ) LO1211 Institutional support: RVO:68081731 Keywords : ESEM * plant waxes * low temperature method Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

  15. Wax solidification of drying agents containing tritiated water

    International Nuclear Information System (INIS)

    Mishikawa, M.; Kido, H.

    1984-01-01

    It is necessary to immobilize the tritium not to give any impact on the environmental biosphere because tritium may give profound effects in the metabolic pathway. One of the most probable methods of immobilizing tritium would be incorporation of tritiated water in solid forms. Any drying or dehydration technique would be effective in a tritium cleanup system for off-gas streams containing tritium or tritiated water. Commonly used drying agents such as activated alumina, silica gel, molecular sieves and calcium sulfate are of value for removal of water vapour from air or other gases. For long term tritium storage, however, these adsorptive materials should be enveloped to prevent contact with water or water vapour because the rate of leaching, evaporation or diffusion of tritium from these porous materials is so large. The beeswax solidification method of the packed bed of drying agents adsorbing tritiated water is developed in this study, where the wax solidification procedure is performed by pouring the melt of wax into the void space of the packed bed of the drying agents and successive gradual cooling. The observed values of diffusivity or permeability of tritium in the wax solidified materials are about one-thousandth of those obtained for the cement block. Effect of coating on the rate of leaching is also discussed

  16. Radiological properties of a wax-gypsum compensator material

    International Nuclear Information System (INIS)

    Plessis, F.C.P. du; Willemse, C.A.

    2005-01-01

    In this paper the radiological properties of a compensator material consisting of wax and gypsum is presented. Effective attenuation coefficients (EACs) have been determined from transmission measurements with an ion chamber in a Perspex phantom. Measurements were made at 80 and 100 cm source-to-skin distance (SSD) for beam energies of 6, 8, and 15 MV, for field sizes ranging from narrow beam geometries up to 40x40 cm 2 , and at measurement depths of maximum dose build-up, 5 and 10 cm. A parametrization equation could be constructed to predict the EAC values within 4% uncertainty as a function of field size and depth of measurement. The EAC dependence on off-axis position was also quantified at each beam energy and SSD. It was found that the compensator material reduced the required thickness for compensation by 26% at 8 MV when compared to pure paraffin wax for a 10x10 cm 2 field. Relative surface ionization (RSI) measurements have been made to quantify the effect of scattered electrons from the wax-gypsum compensator. Results indicated that for 80 cm SSD the RSI would exceed 50% for fields larger than 15x15 cm 2 . At 100 cm SSD the RSI values were below 50% for all field sizes used

  17. Modified paraffin wax for improvement of histological analysis efficiency.

    Science.gov (United States)

    Lim, Jin Ik; Lim, Kook-Jin; Choi, Jin-Young; Lee, Yong-Keun

    2010-08-01

    Paraffin wax is usually used as an embedding medium for histological analysis of natural tissue. However, it is not easy to obtain enough numbers of satisfactory sectioned slices because of the difference in mechanical properties between the paraffin and embedded tissue. We describe a modified paraffin wax that can improve the histological analysis efficiency of natural tissue, composed of paraffin and ethylene vinyl acetate (EVA) resin (0, 3, 5, and 10 wt %). Softening temperature of the paraffin/EVA media was similar to that of paraffin (50-60 degrees C). The paraffin/EVA media dissolved completely in xylene after 30 min at 50 degrees C. Physical properties such as the amount of load under the same compressive displacement, elastic recovery, and crystal intensity increased with increased EVA content. EVA medium (5 wt %) was regarded as an optimal composition, based on the sectioning efficiency measured by the numbers of unimpaired sectioned slices, amount of load under the same compressive displacement, and elastic recovery test. Based on the staining test of sectioned slices embedded in a 5 wt % EVA medium by hematoxylin and eosin (H&E), Masson trichrome (MT), and other staining tests, it was concluded that the modified paraffin wax can improve the histological analysis efficiency with various natural tissues. (c) 2010 Wiley-Liss, Inc.

  18. Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications.

    Science.gov (United States)

    Harry-O'kuru, Rogers E; Biresaw, Girma; Gordon, Sherald; Xu, Jingyuan

    2018-01-01

    Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols mainly C38:2-C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba ( Simmondsia chinensis ) plant which occurs naturally in the Sonora Desert in the United States and northwestern Mexico as well as in the northeastern Sahara desert. The seed contains 50-60% oil by dry weight. The plant has been introduced into Australia, Argentina, and Israel for commercial production of the jojoba oil. As a natural lubricant, we are seeking to explore its potential as a renewable industrial lubricant additive. Thus, we have chemically modified the carbon-carbon double bonds in the oil structure in order to improve its already good resistance to air oxidation so as to enhance its utility as well as its shelf life in nonpersonal care applications. To achieve this goal, we have hydroxylated its -C=C- bonds. Acylation of the resulting hydroxyl moieties has generated short-chain vicinal acyl substituents on the oil which keep the wax liquid, improving its cold flow properties and also protecting it from auto-oxidation and rancidity.

  19. Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications

    Directory of Open Access Journals (Sweden)

    Rogers E. Harry-O’kuru

    2018-01-01

    Full Text Available Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols mainly C38:2–C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba (Simmondsia chinensis plant which occurs naturally in the Sonora Desert in the United States and northwestern Mexico as well as in the northeastern Sahara desert. The seed contains 50–60% oil by dry weight. The plant has been introduced into Australia, Argentina, and Israel for commercial production of the jojoba oil. As a natural lubricant, we are seeking to explore its potential as a renewable industrial lubricant additive. Thus, we have chemically modified the carbon-carbon double bonds in the oil structure in order to improve its already good resistance to air oxidation so as to enhance its utility as well as its shelf life in nonpersonal care applications. To achieve this goal, we have hydroxylated its –C=C– bonds. Acylation of the resulting hydroxyl moieties has generated short-chain vicinal acyl substituents on the oil which keep the wax liquid, improving its cold flow properties and also protecting it from auto-oxidation and rancidity.

  20. SEPARATION OF FISCHER-TROPSCH WAX FROM CATALYST BY SUPERCRITICAL EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Patrick C. Joyce; Mark C. Thies

    1999-03-31

    The objective of this research project was to evaluate the potential of supercritical fluid (SCF) extraction for the recovery and fractionation of the wax product from the slurry bubble column (SBC) reactor of the Fischer-Tropsch (F-T) process. The wax, comprised mostly of branched and linear alkanes with a broad molecular weight distribution up to C{sub 100}, is to be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Aspen Plus{trademark} was used to perform process simulation studies on the proposed extraction process, with Redlich-Kwong-Soave (RKS) being used for the thermodynamic property model. In summary, we have made comprehensive VLE measurements for short alkane + long alkane systems over a wide range of pressures and temperatures, dramatically increasing the amount of high-quality data available for these simple, yet highly relevant systems. In addition, our work has demonstrated that, surprisingly, no current thermodynamic model can adequately predict VLE behavior for these systems. Thus, process simulations (such as those for our proposed SCF extraction process) that incorporate these systems can currently only give results that are qualitative at best. Although significant progress has been made in the past decade, more experimental and theoretical work remain to be done before the phase equilibria of asymmetric alkane mixtures can be predicted with confidence.

  1. Influence of light, UV-B radiation, and herbicides on wax biosynthesis of cucumber seedlings

    International Nuclear Information System (INIS)

    Tevini, M.; Steinmüller, D.

    1987-01-01

    The behavior of cuticular alkane-1-ols and alkanes were studied in different developmental stages of cucumber seedlings grown in the dark or under white light, with or without UV-B radiation or in presence of wax biosynthesis inhibitors, trichloroacetic acid and metolachlor. Accumulation of alkane-1-ols increased light independently with seedling age. Synthesis of alkanes was strictly light and dose dependent. Addition of UV-B radiation did not alter the amounts of alkanes or alcohols, however, the distribution of homologues was shifted towards shorter chain homologues. Treatments with Cl 3 AcOH resulted in strong inhibition of alkane accumulation, whereas the amount of alkane-1-ols was changed neither at low nor at moderate concentrations of Cl 3 AcOH but their homologue distribution shifted towards longer chain lengths. This shifting was depressed in the presence of UV-B. At high concentrations of Cl 3 Ac0H similar homologue distributions as produced by UV-B (shift to shorter homologues) were observed. Metolachlor treatment resulted in an inhibition of alkane-1-ol production connected with rising amounts of alkanes, predominantly of short chain species. A simple model of wax biosynthesis is proposed which describes the interactions with white light, UV-B radiation and herbicides. (author)

  2. Characterization of a plant leaf cuticle model wax, phase behaviour of model wax–water systems

    International Nuclear Information System (INIS)

    Fagerström, Anton; Kocherbitov, Vitaly; Westbye, Peter; Bergström, Karin; Mamontova, Varvara; Engblom, Johan

    2013-01-01

    Highlights: • Four individual crystalline phases were discovered in the model wax–water system. • Eutectic melting occurred in both dry and hydrated model wax. • The total transition enthalpy is smaller for the cuticle wax than for the model wax. • Water has a large plasticizing effect on cuticle wax. • The thermotropic transitions of model wax fit in the window of extracted leaf waxes. - Abstract: We investigated the thermotropic phase behaviour of plant leaf intracuticular wax and two representatives of its main components, 1-docosanol (C 22 H 45 OH) and dotriacontane (C 32 H 66 ), in dry and hydrated state. One objective was to obtain a model wax, which can be used to estimate formulations effects on cuticle diffusivity in vitro. The two wax components were chosen based on results from Gas Chromatography coupled to Mass Spectrometry analysis of cuticular wax. The wax was extracted from Clivia Miniata Regel leaves and contained 68% primary alcohols (C 16 –C 32 ) and 16% n-alkanes (C 21 –C 33 ). Differential Scanning Calorimetry, Polarized Light Microscopy and Small- and Wide Angle X-ray Diffraction were used to characterize the cuticular extract and the phase behaviour of the C 22 H 45 OH/C 32 H 66 /H 2 O model system. Four individual crystalline phases were discovered in the model wax–water system and eutectic melting occurred in both dry and hydrated state. The thermotropic transitions of the model wax occur within the broader transition region of the extracted leaf wax

  3. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent.

    Science.gov (United States)

    Patel, Ashok R; Babaahmadi, Mehrnoosh; Lesaffer, Ans; Dewettinck, Koen

    2015-05-20

    The aim of this study was to use a detailed rheological characterization to gain new insights into the gelation behavior of natural waxes. To make a comprehensive case, six natural waxes (differing in the relative proportion of chemical components: hydrocarbons, fatty alcohols, fatty acids, and wax esters) were selected as organogelators to gel high-oleic sunflower oil. Flow and dynamic rheological properties of organogels prepared at critical gelling concentrations (Cg) of waxes were studied and compared using drag (stress ramp and steady flow) and oscillatory shear (stress and frequency sweeps) tests. Although, none of the organogels satisfied the rheological definition of a "strong gel" (G″/G' (ω) ≤ 0.1), on comparing the samples, the strongest gel (highest critical stress and dynamic, apparent, and static yield stresses) was obtained not with wax containing the highest proportion of wax esters alone (sunflower wax, SFW) but with wax containing wax esters along with a higher proportion of fatty alcohols (carnauba wax, CRW) although at a comparatively higher Cg (4%wt for latter compared to 0.5%wt for former). As expected, gel formation by waxes containing a high proportion of lower melting fatty acids (berry, BW, and fruit wax, FW) required a comparatively higher Cg (6 and 7%wt, respectively), and in addition, these gels showed the lowest values for plateau elastic modulus (G'LVR) and a prominent crossover point at higher frequency. The gelation temperatures (TG'=G″) for all the studied gels were lower than room temperature, except for SFW and CRW. The yielding-type behavior of gels was evident, with most gels showing strong shear sensitivity and a weak thixotropic recovery. The rheological behavior was combined with the results of thermal analysis and microstructure studies (optical, polarized, and cryo-scanning electron microscopy) to explain the gelation properties of these waxes.

  4. Characterization of a plant leaf cuticle model wax, phase behaviour of model wax–water systems

    Energy Technology Data Exchange (ETDEWEB)

    Fagerström, Anton, E-mail: anton.fagerstrom@mah.se [Biomedical Science, Faculty of Health and Society, Malmö University, Malmö (Sweden); Kocherbitov, Vitaly [Biomedical Science, Faculty of Health and Society, Malmö University, Malmö (Sweden); Westbye, Peter; Bergström, Karin [Agro Applications Europe, AkzoNobel Surface Chemistry AB, Stenungsund (Sweden); Mamontova, Varvara [Ecological and Chemical Research, St. Petersburg Scientific Research Center for Ecological Safety, Russian Academy of Sciences, St. Petersburg (Russian Federation); Engblom, Johan [Biomedical Science, Faculty of Health and Society, Malmö University, Malmö (Sweden)

    2013-11-10

    Highlights: • Four individual crystalline phases were discovered in the model wax–water system. • Eutectic melting occurred in both dry and hydrated model wax. • The total transition enthalpy is smaller for the cuticle wax than for the model wax. • Water has a large plasticizing effect on cuticle wax. • The thermotropic transitions of model wax fit in the window of extracted leaf waxes. - Abstract: We investigated the thermotropic phase behaviour of plant leaf intracuticular wax and two representatives of its main components, 1-docosanol (C{sub 22}H{sub 45}OH) and dotriacontane (C{sub 32}H{sub 66}), in dry and hydrated state. One objective was to obtain a model wax, which can be used to estimate formulations effects on cuticle diffusivity in vitro. The two wax components were chosen based on results from Gas Chromatography coupled to Mass Spectrometry analysis of cuticular wax. The wax was extracted from Clivia Miniata Regel leaves and contained 68% primary alcohols (C{sub 16}–C{sub 32}) and 16% n-alkanes (C{sub 21}–C{sub 33}). Differential Scanning Calorimetry, Polarized Light Microscopy and Small- and Wide Angle X-ray Diffraction were used to characterize the cuticular extract and the phase behaviour of the C{sub 22}H{sub 45}OH/C{sub 32}H{sub 66}/H{sub 2}O model system. Four individual crystalline phases were discovered in the model wax–water system and eutectic melting occurred in both dry and hydrated state. The thermotropic transitions of the model wax occur within the broader transition region of the extracted leaf wax.

  5. Rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae produces multiple DSF-family signals in regulation of virulence factor production

    Directory of Open Access Journals (Sweden)

    Cha Jae-Soon

    2010-07-01

    Full Text Available Abstract Background Xanthomonas oryzae pv. oryzae (Xoo is the causal agent of rice bacterial blight disease. Xoo produces a range of virulence factors, including EPS, extracellular enzyme, iron-chelating siderophores, and type III-secretion dependent effectors, which are collectively essential for virulence. Genetic and genomics evidence suggest that Xoo might use the diffusible signal factor (DSF type quorum sensing (QS system to regulate the virulence factor production. However, little is known about the chemical structure of the DSF-like signal(s produced by Xoo and the factors influencing the signal production. Results Xoo genome harbours an rpf cluster comprising rpfB, rpfF, rpfC and rpfG. The proteins encoded by these genes are highly homologous to their counterparts in X. campestris pv. campestris (Xcc, suggesting that Xcc and Xoo might use similar mechanisms for DSF biosynthesis and autoregulation. Consistent with in silico analysis, the rpfF mutant was DSF-deficient and the rpfC mutant produced about 25 times higher DSF-like activity than the wild type Xoo strain KACC10331. From the supernatants of rpfC mutant, we purified three compounds showing strong DSF-like activity. Mass spectrometry and NMR analysis revealed that two of them were the previously characterized DSF and BDSF; the third one was a novel unsaturated fatty acid with 2 double bonds and was designated as CDSF in this study. Further analysis showed that all the three DSF-family signals were synthesized via the enzyme RpfF encoded by Xoo2868. DSF and BDSF at a final concentration of 3 μM to the rpfF mutant could fully restore its extracellular xylanase activity and EPS production to the wild type level, but CDSF was less active than DSF and BDSF in induction of EPS and xylanase. DSF and CDSF shared a similar cell density-dependent production time course with the maximum production being detected at 42 h after inoculation, whereas the maximum production of BDSF was observed

  6. McWRI1, a transcription factor of the AP2/SHEN family, regulates the biosynthesis of the cuticular waxes on the apple fruit surface under low temperature

    Science.gov (United States)

    Ji, Qianlong; Zhang, Kezhong; Yang, Mingfeng

    2017-01-01

    Cuticular waxes of plant and organ surfaces play an important role in protecting plants from biotic and abiotic stress and extending the freshness, storage time and shelf life in the post-harvest agricultural products. WRI1, a transcription factor of AP2/SHEN families, had been found to trigger the related genes taking part in the biosynthesis of seed oil in many plants. But whether WRI1 is involved in the biosynthesis of the cuticular waxes on the Malus fruits surface has been unclear. We investigated the changes of wax composition and structure, the related genes and WRI1 expression on Malus asiatica Nakai and sieversii fruits with the low temperature treatments, found that low temperature induced the up-regulated expression of McWRI1, which promoted gene expression of McKCS, McLACs and McWAX in very-long-chain fatty acid biosynthesis pathway, resulting in the accumulation of alkanes component and alteration of wax structure on the fruit surface. Corresponding results were verified in McWRI1 silenced by VIGS, and WRI1 silenced down-regulated the related genes on two kinds of fruits, it caused the diversity alteration in content of some alkanes, fatty acid and ester component in two kinds of fruits. We further conducted Y1H assay to find that McWRI1 transcription factor activated the promoter of McKCS, McLAC and McWAX to regulate their expression. These results demonstrated that McWRI1 is involved in regulating the genes related synthesis of very long chain fatty acid on surface of apple fruits in storage process, providing a highlight for improvement of the modified atmosphere storage of apple fruits. PMID:29073205

  7. Evaluation of hyperimmune colostrum production in bovine against cariogenic streptococci and its impact on growth and bacterial biofilm formation

    Directory of Open Access Journals (Sweden)

    Fateme Ramezanalizadeh

    2017-03-01

    Full Text Available Background and Aims: Dental caries is the most common infectious diseases. Among the oral bacteria, Streptococcus mutans and Streptococcus sobrinus are considered as the main causes of tooth decay. The aim of this study was to evaluate the production of hyperimmune bovine colostrum containing specific antibodies against cariogenic bacteria and its antimicrobial effects on the growth and adhesion of Streptococcus mutans and Streptococcus sobrinus in the laboratory. Materials and Methods: In this experimental study, three pregnant bovine immunized with killed antigens of strains of Streptococcus mutans, Streptococcus mutans with Streptococcus Sobrinus and Streptococcus sobrinus through intramuscular injections. After delivery, The colostrum samples were collected, and the changes of anti-streptococci antibodies titers in colostrum and serum were determined by agglutination. Also,their antimicrobial effects against the growth and adhesion of oral streptococci were surveyed by the microtiter plate method. Data were analysed by One-Wey ANOVA in SPSS software. Results: The results showed that in hyperimmunized bovine , the antibodies titers against injected bacteria were from 1.1000 to 1.3000 in sera samples and from 1.320 to 1.1280 in whey of colostrum samples. Colostrum of hyperimmune cows reduced the attachment of Streptococcus mutans and Streptococcus Sobrinus about 69 and 43 percents, respectively and also, the low dilutions of it reduced bacterial growth. Conclusion:  According to the antibacterial effect immune colostrum on two strains of cariogenic bacteria in vitro, It appears that this material could be useful in the prevention and control of dental caries.

  8. Effects of dietary inulin on bacterial growth, short-chain fatty acid production and hepatic lipid metabolism in gnotobiotic mice.

    Science.gov (United States)

    Weitkunat, Karolin; Schumann, Sara; Petzke, Klaus Jürgen; Blaut, Michael; Loh, Gunnar; Klaus, Susanne

    2015-09-01

    In literature, contradictory effects of dietary fibers and their fermentation products, short-chain fatty acids (SCFA), are described: On one hand, they increase satiety, but on the other hand, they provide additional energy and promote obesity development. We aimed to answer this paradox by investigating the effects of fermentable and non-fermentable fibers on obesity induced by high-fat diet in gnotobiotic C3H/HeOuJ mice colonized with a simplified human microbiota. Mice were fed a high-fat diet supplemented either with 10% cellulose (non-fermentable) or inulin (fermentable) for 6 weeks. Feeding the inulin diet resulted in an increased diet digestibility and reduced feces energy, compared to the cellulose diet with no differences in food intake, suggesting an increased intestinal energy extraction from inulin. However, we observed no increase in body fat/weight. The additional energy provided by the inulin diet led to an increased bacterial proliferation in this group. Supplementation of inulin resulted further in significantly elevated concentrations of total SCFA in cecum and portal vein plasma, with a reduced cecal acetate:propionate ratio. Hepatic expression of genes involved in lipogenesis (Fasn, Gpam) and fatty acid elongation/desaturation (Scd1, Elovl3, Elovl6, Elovl5, Fads1 and Fads2) were decreased in inulin-fed animals. Accordingly, plasma and liver phospholipid composition were changed between the different feeding groups. Concentrations of omega-3 and odd-chain fatty acids were increased in inulin-fed mice, whereas omega-6 fatty acids were reduced. Taken together, these data indicate that, during this short-term feeding, inulin has mainly positive effects on the lipid metabolism, which could cause beneficial effects during obesity development in long-term studies. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Development of hydrophilic dental wax without surfactant using a non-thermal air atmospheric pressure plasma jet

    International Nuclear Information System (INIS)

    Lee, Jung-Hwan; Kim, Kwang-Mahn; Kim, Kyoung-Nam; Kim, Yong-Hee; Choi, Eun-Ha

    2014-01-01

    Dental wax (DW), a low-melting and high-molecular-weight organic mixture, is widely used in dentistry for forming moulds of teeth. Hydrophilicity is an important property for DW, as a wet dental investment is used to surround the wax before wax burnout is performed. However, recent attempts to improve the hydrophilicity of DW using a surfactant have resulted in the reduced mechanical properties of the dental investment, leading to the failure of the dental restoration. This study applied a non-thermal air atmospheric pressure plasma jet (AAPPJ) for DW surface treatment and investigated its effect on both DW hydrophilicity and the dental investment's mechanical properties. The results showed that the application of the AAPPJ significantly improved the hydrophilicity of the DW, and that the results were similar to that of cleaner-treated DW using commercially available products with surfactant. A surface chemical analysis indicated that the improvement of hydrophilicity was related to an increase in the number of oxygen-related bonds on the DW surface following the removal of carbon hydrate in both AAPPJ and cleaner-treated DW. However, cleaner treatment compromised the mechanical property of the dental investment when the dental investment was in contact with the treated DW, while the AAPPJ treatment did not. Therefore, the use of AAPPJ to treat DW is a promising method for accurate dental restoration, as it induces an improvement in hydrophilicity without harming the dental investment. (paper)

  10. The Use of Biobased Surfactant Obtained by Enzymatic Syntheses for Wax Deposition Inhibition and Drag Reduction in Crude Oil Pipelines

    Directory of Open Access Journals (Sweden)

    Zhihua Wang

    2016-04-01

    Full Text Available Crude oil plays an important role in providing the energy supply of the world, and pipelines have long been recognized as the safest and most efficient means of transporting oil and its products. However, the transportation process also faces the challenges of asphaltene-paraffin structural interactions, pipeline pressure losses and energy consumption. In order to determine the role of drag-reducing surfactant additives in the transportation of crude oils, experiments of wax deposition inhibition and drag reduction of different oil in pipelines with a biobased surfactant obtained by enzymatic syntheses were carried out. The results indicated that heavy oil transportation in the pipeline is remarkably enhanced by creating stable oil-in-water (O/W emulsion with the surfactant additive. The wax appearance temperature (WAT and pour point were modified, and the formation of a space-filling network of interlocking wax crystals was prevented at low temperature by adding a small concentration of the surfactant additive. A maximum viscosity reduction of 70% and a drag reduction of 40% for light crude oil flows in pipelines were obtained with the surfactant additive at a concentration of 100 mg/L. Furthermore, a successful field application of the drag-reducing surfactant in a light crude oil pipeline in Daqing Oilfield was demonstrated. Hence, the use of biobased surfactant obtained by enzymatic syntheses in oil transportation is a potential method to address the current challenges, which could result in a significant energy savings and a considerable reduction of the operating cost.

  11. Comparison of the efficiency of bacterial and fungal laccases in delignification and detoxification of steam-pretreated lignocellulosic biomass for bioethanol production.

    Science.gov (United States)

    De La Torre, María; Martín-Sampedro, Raquel; Fillat, Úrsula; Eugenio, María E; Blánquez, Alba; Hernández, Manuel; Arias, María E; Ibarra, David

    2017-11-01

    This study evaluates the potential of a bacterial laccase from Streptomyces ipomoeae (SilA) for delignification and detoxification of steam-exploded wheat straw, in comparison with a commercial fungal laccase from Trametes villosa. When alkali extraction followed by SilA laccase treatment was applied to the water insoluble solids fraction, a slight reduction in lignin content was detected, and after a saccharification step, an increase in both glucose and xylose production (16 and 6%, respectively) was observed. These effects were not produced with T. villosa laccase. Concerning to the fermentation process, the treatment of the steam-exploded whole slurry with both laccases produced a decrease in the phenol content by up to 35 and 71% with bacterial and fungal laccases, respectively. The phenols reduction resulted in an improved performance of Saccharomyces cerevisiae during a simultaneous saccharification and fermentation (SSF) process, improving ethanol production rate. This enhancement was more marked with a presaccharification step prior to the SSF process.

  12. Role of Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase in Oleaginous Streptomyces sp. Strain G25

    Science.gov (United States)

    Röttig, Annika; Strittmatter, Carl Simon; Schauer, Jennifer; Hiessl, Sebastian; Daniel, Rolf

    2016-01-01

    ABSTRACT Recently, we isolated a novel Streptomyces strain which can accumulate extraordinarily large amounts of triacylglycerol (TAG) and consists of 64% fatty acids (dry weight) when cultivated with glucose and 50% fatty acids (dry weight) when cultivated with cellobiose. To identify putative gene products responsible for lipid storage and cellobiose utilization, we analyzed its draft genome sequence. A single gene encoding a wax ester synthase/acyl coenzyme A (CoA):diacylglycerol acyltransferase (WS/DGAT) was identified and heterologously expressed in Escherichia coli. The purified enzyme AtfG25 showed acyltransferase activity with C12- or C16-acyl-CoA, C12 to C18 alcohols, or dipalmitoyl glycerol. This acyltransferase exhibits 24% amino acid identity to the model enzyme AtfA from Acinetobacter baylyi but has high sequence similarities to WS/DGATs from other Streptomyces species. To investigate the impact of AtfG25 on lipid accumulation, the respective gene, atfG25, was inactivated in Streptomyces sp. strain G25. However, cells of the insertion mutant still exhibited DGAT activity and were able to store TAG, albeit in lower quantities and at lower rates than the wild-type strain. These findings clearly indicate that AtfG25 has an important, but not exclusive, role in TAG biosynthesis in the novel Streptomyces isolate and suggest the presence of alternative metabolic pathways for lipid accumulation which are discussed in the present study. IMPORTANCE A novel Streptomyces strain was isolated from desert soil, which represents an extreme environment with high temperatures, frequent drought, and nutrient scarcity. We believe that these harsh conditions promoted the development of the capacity for this strain to accumulate extraordinarily large amounts of lipids. In this study, we present the analysis of its draft genome sequence with a special focus on enzymes potentially involved in its lipid storage. Furthermore, the activity and importance of the detected

  13. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  14. Bacterial carbohydrate-degrading capacity in foal faeces: changes from birth to pre-weaning and the impact of maternal supplementation with fermented feed products.

    Science.gov (United States)

    Faubladier, Céline; Julliand, Véronique; Danel, Justine; Philippeau, Christelle

    2013-09-28

    The present study aimed at (1) describing age-related changes in faecal bacterial functional groups involved in carbohydrate degradation and in their activities in foals (n 10) from birth (day (d) 0) to 6 months (d180) and (2) investigating the effect of maternal supplementation (five mares per treatment) from d - 45 to d60 with fermented feed products on response trends over time of the foal bacterial carbohydratedegrading capacity. Maternal supplementation with fermented feed products stimulated foal growth from d0 to d60 and had an impact on the establishment of some digestive bacterial groups and their activities in foals from d0 to d5 but not in the longer term. Irrespective of the maternal treatment, total bacteria, total anaerobic, lactate-utilising and amylolytic bacteria were established immediately after birth (Panaerobes and lactate utilisers were established rapidly between d0 and d2 (P=0·021 and 0·066, respectively) and the increase in the percentage of propionate occurred earlier (P=0·013). Maternal supplementation had no effect on the establishment of fibrolytic bacteria and their activity. Cellulolytic bacteria and Fibrobacter succinogenes first appeared at d2 and d5, and increased progressively, reaching stable values at d30 and d60, respectively. From the second week of life, the increase in the molar percentage of acetate and the ratio (acetate + butyrate):propionate (P<0·05) suggested that fibrolytic activity had begun. From d60, only minor changes in bacterial composition and activities occurred, showing that the bacterial carbohydrate-degrading capacity was established at 2 months of age.

  15. Effect of waste wax and chain structure on the mechanical and physical properties of polyethylene

    Directory of Open Access Journals (Sweden)

    M.A. AlMaadeed

    2015-05-01

    The wax dispersion in the matrix strongly depends on the percentage of wax added to the polymer and the molecular structure of the polymer. It was found that increasing the wax content enhances the phase separation. LDPE undergoes less phase separation due to its highly branched structure composed of a network of short and long chain branches. The wax has no pronounced plasticising effect on the polymer. This is clearly manifested in LDPE as no change in the melting temperature occurred. LLDPE and HDPE were slightly affected by a high concentration of wax (30% and 40%. This is due to the non-uniform distribution of short chain branching along the LLDPE and HDPE main chains, which can interact with the wax structure.

  16. Effects of sunflower wax coating on physicochemical changes of mangifera indica L. in storage life

    International Nuclear Information System (INIS)

    Soomro, R.K.; Sherazi, S.T.H.

    2013-01-01

    Mango (Mangifera indica L.) fruit has a relatively short storage life due to perishable nature. In order to increases the storage life of langra mangoes, fruits were coated with sunflower wax. Mangoes were stored at room and refrigerated temperature. Sunflower wax coating protects the mangoes in greater proportion to change their color, weight loss, moisture loss, pH and total soluble solids content. The sensorial panel also favors the grander role of sunflower wax coating. Application of sunflower wax coatings had no effect on vitamin C content of mangoes variety and could increases mango storage time around 30 days under regular storage conditions. Sunflower wax coating also inhibited the growth of micro-organisms. The data reveal that by applying a sunflower wax coating effectively prolongs the quality which attributes and extends the shelf life of mango. (author)

  17. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    compounds these must first be undergo extracellular hydrolysis. Bacteria have a great diversity with respect to types of metabolism that far exceeds the metabolic repertoire of eukaryotic organisms. Bacteria play a fundamental role in the biosphere and certain key processes such as, for example......, the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  18. Characterization and chemical composition of epicuticular wax from banana leaves grown in Northern Thailand

    OpenAIRE

    Suporn Charumanee; Songwut Yotsawimonwat; Panee Sirisa-ard; Kiatisak Pholsongkram

    2017-01-01

    This study aimed to investigate the physicochemical properties and chemical composition of epicuticular wax extracted from leaves of Kluai Namwa, a banana cultivar which is widely grown in Northern Thailand. Its genotype was identified by a botanist. The wax was extracted using solvent extraction. The fatty acid profiles and physicochemical properties of the wax namely melting point, congealing point, crystal structures and polymorphism, hardness, color, and solubility were examin...

  19. Methods for separating boron from borated paraffin wax and its determination by ion chromatography

    International Nuclear Information System (INIS)

    Jeyakumar, S.

    2015-01-01

    Boron compounds are found to be useful in shielding against high-energy neutrons. In radiotherapy treatments, in order to protect occupational workers and patients from the undesirable neutron and gamma doses, paraffin wax containing B 4 C/boric acid is used. Low-level borate wastes generated from the nuclear power plants have been immobilized with paraffin wax using a concentrate waste drying system (CWDS). Borated paraffin waxes are prepared by mixing calculated amounts of either boric acid or boron carbide with the molten wax. This necessitates the determination of boron at different locations in order to check the homogeneous distribution of B over the borated wax. The determination of boron in nuclear materials is inevitable due to its high neutron absorption cross section. For the determination of boron in borated waxes, not many methods have been reported. A method based on the pyrohydrolysis extraction of boron and its quantification with ion chromatography was proposed for paraffin waxes borated with H 3 BO 3 and B 4 C. The B 4 C optimum pyrohydrolysis conditions were identified. Wax samples were mixed with U 3 O 8 , which prevents the sample from flare up, and also accelerates the extraction of boron. Pyrohydrolysis was carried out with moist O 2 at 950℃ for 60 and 90 min for wax with H 3 BO 3 and wax with B 4 C, respectively. Two simple methods of separation based on alkali extraction and melting wax in alkali were also developed exclusively for wax with H 3 BO 3 . In all the separations, the recovery of B was above 98%. During IC separation, B was separated as boron-mannitol anion complex. Linear calibration was obtained between 0.1 and 50 ppm of B, and LOD was calculated as 5 ppb (S/N=3). The reproducibility was better than 5% (RSD)

  20. The Occurrence of Paraffin and Other Petroleum Waxes in the Marine Environment: A Review of the Current Legislative Framework and Shipping Operational Practices

    Directory of Open Access Journals (Sweden)

    Giuseppe Suaria

    2018-03-01

    Full Text Available Among the various materials that make up marine debris, lumps of petroleum waxes such as paraffin and microcrystalline wax, are regularly found on beaches worldwide, although not included in the current definition of marine litter. Ingestion by marine organisms is occasionally documented in the scientific literature and mass beaching events are frequently reported along the European coasts, with obvious detrimental consequences to the local communities that have to manage the clean-up and disposal of this substance. According to Annex II of the MARPOL regulation, petroleum waxes are classified as “high viscosity, solidifying, and persistent floating products,” whose discharge at sea of tank-washing residues is strictly regulated, but currently permitted within certain limits. Starting from the description of a large stranding event occurred along the Italian coasts in 2017, we review the existing knowledge and regulatory framework and urge the relevant authorities to address this issue, showing that wax pollution is creating evident damages to the European coastal municipalities. Pending further investigations on the potential hazard that this kind of pollution is posing to marine ecosystems, we suggest a careful and more stringent revision of the policies regulating discharges of these products at sea.

  1. Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing.

    LENUS (Irish Health Repository)

    Power, C

    2012-02-03

    INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR\\/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis. MATERIALS AND METHODS: We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP. RESULTS: Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble\\/serum CD14, a highly specific bacterial wall product receptor, in

  2. Antiprotozoal activity of extracts and isolated triterpenoids of 'carnauba' (Copernicia prunifera) wax from Brazil.

    Science.gov (United States)

    de Almeida, Buana C; Araújo, Bruno Q; Carvalho, Adonias A; Freitas, Sâmya Danielle L; Maciel, Dayany da S Alves; Ferreira, Ari José S; Tempone, Andre G; Martins, Ligia F; Alexandre, Tatiana R; Chaves, Mariana H; Lago, João Henrique G

    2016-12-01

    'Carnauba' wax is a natural product obtained from the processing of the powder exuded from Copernicia prunifera (Miller) H. E. Moore (Arecaceae). This material is widely used in the Brazilian folk medicine, including the treatment of rheumatism and syphilis. To investigate the antiprotozoal activity of hexane and EtOH extracts from the 'carnauba' wax as well as from the isolated compounds from the bioactive extracts. Two different samples of 'carnauba' (C. prunifera) waxes - types 1 and 4 - were individually extracted using hexane (EH) and EtOH (EE). Aliquots of hexane (type 1 - EH-1 and EH-4) and EtOH (type 4 - EE-1 and EE-4) extracts were tested against promastigote (2-200 μg/mL in DMSO during 48 h at 24 °C) and amastigote (3-150 μg/mL in DMSO during 120 h at 37 °C) forms of Leishmania infantum as well as against trypomastigote (3-150 μg/mL in DMSO during 24 h at 37 °C) forms of Trypanosoma cruzi. Bioactive extracts EH-1 and EE-4 were subjected to a bioactivity-guided fractionation to afford three dammarane-type triterpenoids (1-3). The in vitro antiprotozoal activities of the obtained compounds were evaluated as described above. Additionally, the cytotoxicity activity of compounds 1-3 against mammalian conjunctive cells (NCTC - 2-200 μg/mL in DMSO during 48 h at 37 °C) was determined. From the bioactive hexane and EtOH extracts from the 'carnauba' (C. prunifera) wax, were isolated three dammarane-type triterpenoids: (24R*)-methyldammar-25-ene-3β,20-diol (carnaubadiol, 1), (24R*)-methyldammara-20,25-dien-3-one (2) and (24R*)-methyldammara-20,25-dien-3α-ol (3). These compounds were identified based on the analysis of NMR and MS spectroscopic data. Compounds 1-3 were effective against the intracellular amastigotes of L. infantum, with IC 50 values ranging from 8 to 52 μM, while compounds 1 and 3 displayed activity against trypomastigote forms of T. cruzi with IC 50 values of 15 and 35 μM, respectively. The mammalian

  3. The MIEL1 E3 Ubiquitin Ligase Negatively Regulates Cuticular Wax Biosynthesis in Arabidopsis Stems.

    Science.gov (United States)

    Lee, Hong Gil; Kim, Juyoung; Suh, Mi Chung; Seo, Pil Joon

    2017-07-01

    Cuticular wax is an important hydrophobic layer that covers the plant aerial surface. Cuticular wax biosynthesis is shaped by multiple layers of regulation. In particular, a pair of R2R3-type MYB transcription factors, MYB96 and MYB30, are known to be the main participants in cuticular wax accumulation. Here, we report that the MYB30-INTERACTING E3 LIGASE 1 (MIEL1) E3 ubiquitin ligase controls the protein stability of the two MYB transcription factors and thereby wax biosynthesis in Arabidopsis. MIEL1-deficient miel1 mutants exhibit increased wax accumulation in stems, with up-regulation of wax biosynthetic genes targeted by MYB96 and MYB30. Genetic analysis reveals that wax accumulation of the miel1 mutant is compromised by myb96 or myb30 mutation, but MYB96 is mainly epistatic to MIEL1, playing a predominant role in cuticular wax deposition. These observations indicate that the MIEL1-MYB96 module is important for balanced cuticular wax biosynthesis in developing inflorescence stems. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Structural-mechanical model of wax crystal networks—a mesoscale cellular solid approach

    International Nuclear Information System (INIS)

    Miyazaki, Yukihiro; Marangoni, Alejandro G

    2014-01-01

    Mineral waxes are widely used materials in industrial applications; however, the relationship between structure and mechanical properties is poorly understood. In this work, mineral wax-oil networks were characterized as closed-cell cellular solids, and differences in their mechanical response predicted from structural data. The systems studied included straight-chain paraffin wax (SW)-oil mixtures and polyethylene wax (PW)-oil mixtures. Analysis of cryogenic-SEM images of wax-oil networks allowed for the determination of the length (l) and thickness (t) of the wax cell walls as a function of wax mass fraction (Φ). A linear relationship between t/l and Φ (t/l ∼ Φ 0.89 ) suggested that wax-oil networks were cellular solids of the closed-cell type. However, the scaling behavior of the elastic modulus with the volume fraction of solids did not agree with theoretical predictions, yielding the same scaling exponent, μ = 0.84, for both waxes. This scaling exponent obtained from mechanical measurements could be predicted from the scaling behavior of the effective wax cell size as a function of wax mass fraction in oil obtained by cryogenic scanning electron microscopy. Microscopy studies allowed us to propose that wax-oil networks are structured as an ensemble of close-packed spherical cells filled with oil, and that it is the links between cells that yield under simple uniaxial compression. Thus, the Young’s moduli for the links between cells in SW and PW wax systems could be estimated as E L (SW) = 2.76 × 10 9 Pa and E L (PW) = 1.64 × 10 9 Pa, respectively. The structural parameter responsible for the observed differences in the mechanical strength between the two wax-oil systems is the size of the cells. Polyethylene wax has much smaller cell sizes than the straight chain wax and thus displays a higher Young’s modulus and yield stress. (papers)

  5. Characterization of rice bran wax policosanol and its nanoemulsion formulation

    Directory of Open Access Journals (Sweden)

    Ishaka A

    2014-05-01

    Full Text Available Aminu Ishaka,1,2 Mustapha Umar Imam,1 Rozi Mahamud,3 Abu Bakar Zakaria Zuki,4 Ismail Maznah1 1Laboratory of Molecular Biomedicine, Institute of Bioscience, University Putra Malaysia, Serdang, Selangor, Malaysia; 2Department of Medical Biochemistry, College of Health Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria; 3Faculty of Medicine and Health Sciences, 4Faculty of Veterinary Medicine, University Putra Malaysia, Serdang, Selangor, Malaysia Abstract: Policosanol, a mixture of long-chain alcohols found in animal and plant waxes, has several biological effects; however, it has a bioavailability of less than 10%. Therefore, there is a need to improve its bioavailability, and one of the ways of doing this is by nanoemulsion formulation. Different droplet size distributions are usually achieved when emulsions are formed, which solely depends on the preparation method used. Mostly, emulsions are intended for better delivery with maintenance of the characteristics and properties of the leading components. In this study, policosanol was extracted from rice bran wax, its composition was determined by gas chromatography mass spectrophotometry, nanoemulsion was made, and the physical stability characteristics were determined. The results showed that policosanol nanoemulsion has a nanosize particle distribution below 100 nm (92.56–94.52 nm, with optimum charge distribution (-55.8 to -45.12 mV, pH (6.79–6.92 and refractive index (1.50; these were monitored and found to be stable for 8 weeks. The stability of policosanol nanoemulsion confers the potential to withstand long storage times. Keywords: rice bran wax, policosanol, nanoemulsion, characterization

  6. Effect of Different Carbon Sources on Bacterial Nanocellulose Production and Structure Using the Low pH Resistant Strain Komagataeibacter Medellinensis

    Directory of Open Access Journals (Sweden)

    Carlos Molina-Ramírez

    2017-06-01

    Full Text Available Bacterial cellulose (BC is a polymer obtained by fermentation with microorganism of different genera. Recently, new producer species have been discovered, which require identification of the most important variables affecting cellulose production. In this work, the influence of different carbon sources in BC production by a novel low pH-resistant strain Komagataeibacter medellinensis was established. The Hestrin-Schramm culture medium was used as a reference and was compared to other media comprising glucose, fructose, and sucrose, used as carbon sources at three concentrations (1, 2, and 3% w/v. The BC yield and dynamics of carbon consumption were determined at given fermentation times during cellulose production. While the carbon source did not influence the BC structural characteristics, different production levels were determined: glucose > sucrose > fructose. These results highlight considerations to improve BC industrial production and to establish the BC property space for applications in different fields.

  7. Laser-assisted fabrication of batteries on wax paper

    International Nuclear Information System (INIS)

    Chitnis, G; Ziaie, B; Tan, T

    2013-01-01

    The functionality of paper-based diagnostic devices can be significantly enhanced by their integration with an on-board energy source. Here, we demonstrate the fabrication of paper-based electrochemical cells on wax paper using CO 2 laser surface treatment and micromachining. A four cell zinc–copper battery shows a steady open-circuit voltage of ∼3 V and can provide 0.25 mA for at least 30 min when connected to a 10 kΩ load. Higher voltages and current values can be obtained by adjusting the number and size of electrochemical cells in the battery without changing the fabrication process. (paper)

  8. Two bifunctional enzymes from the marine protist Thraustochytrium roseum: biochemical characterization of wax ester synthase/acyl-CoA:diacylglycerol acyltransferase activity catalyzing wax ester and triacylglycerol synthesis.

    Science.gov (United States)

    Zhang, Nannan; Mao, Zejing; Luo, Ling; Wan, Xia; Huang, Fenghong; Gong, Yangmin

    2017-01-01

    Triacylglycerols (TAGs) and wax esters (WEs) are important neutral lipids which serve as energy reservoir in some plants and microorganisms. In recent years, these biologically produced neutral lipids have been regarded as potential alternative energy sources for biofuel production because of the increased interest on developing renewable and environmentally benign alternatives for fossil fuels. In bacteria, the final step in TAG and WE biosynthetic pathway is catalyzed by wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT). This bifunctional WS/DGAT enzyme is also a key enzyme in biotechnological production of liquid WE via engineering of plants and microorganisms. To date, knowledge about this class of biologically and biotechnologically important enzymes is mainly from biochemical characterization of WS/DGATs from Arabidopsis, jojoba and some bacteria that can synthesize both TAGs and WEs intracellularly, whereas little is known about WS/DGATs from eukaryotic microorganisms. Here, we report the identification and characterization of two bifunctional WS/DGAT enzymes (designated TrWSD4 and TrWSD5) from the marine protist Thraustochytrium roseum . Both TrWSD4 and TrWSD5 comprise a WS-like acyl-CoA acyltransferase domain and the recombinant proteins purified from Escherichia coli Rosetta (DE3) have substantial WS and lower DGAT activity. They exhibit WS activity towards various-chain-length saturated and polyunsaturated acyl-CoAs and fatty alcohols ranging from C 10 to C 18 . TrWSD4 displays WS activity with the lowest K m value of 0.14 μM and the highest k cat / K m value of 1.46 × 10 5  M -1  s -1 for lauroyl-CoA (C 12:0 ) in the presence of 100 μM hexadecanol, while TrWSD5 exhibits WS activity with the lowest K m value of 0.96 μM and the highest k cat / K m value of 9.83 × 10 4  M -1  s -1 for decanoyl-CoA (C 10:0 ) under the same reaction condition. Both WS/DGAT enzymes have the highest WS activity at 37 and 47

  9. Propolis and vegetable wax in the conservation of Hass avocadoPrópolis e cera vegetal na conservação de abacate Hass

    Directory of Open Access Journals (Sweden)

    Ricardo de Oliveira Orsi

    2012-08-01

    Full Text Available The aim of this work was to evaluate the quality of Hass avocado submitted to application of propolis and vegetable wax. The selected fruits were submitted to the treatments (1 without wax and without propolis, (2 with vegetable wax, (3 propolis alcoholic extract 100%, (4 wax and etanol 70%, (5 propolis alcoholic extract 2% and wax, (6 propolis alcoholic extract 4% and wax, (7 propolis alcoholic extract 6% and wax, (8 propolis alcoholic extract 8% and wax, and (9 propolis alcoholic extract 10% and wax. The fruits were maintained under refrigeration (10 ± 1 ºC and 90 ± 5% relative humidity, being appraised every three days for 15 days and more 3 days of commercialization simulation at room temperature (23± 1 ºC and 18% relative humidity.The evaluation parameters were the weight loss, respiratory activity, pH, firmness, tritable acidity (AT, soluble solids (SS, and ratio. The results of weigth loss, respiratory activity and firmness were the most significant to show the difference among the treatments. ‘Hass’ avocado fruits submitted the application of propolis associated the vegetable wax present smaller weight loss, CO2 production and firmness in relation to the control fruits. The fruits of the treatment with propolis alcoholic extract 2% and wax presented the most promising results. Objetivou-se neste trabalho avaliar a aplicação de própolis e cera vegetal na qualidade pós-colheita do abacate ‘Hass’. Os frutos selecionados foram submetidos aos tratamentos (1 sem cera e sem própolis, (2 com cera vegetal, (3 extrato alcoólico de própolis 100%, (4 cera e etanol 70%, (5 extrato alcoólico de própolis 2% e cera, (6 extrato alcoólico de própolis 4% e cera, (7 extrato alcoólico de própolis 6% e cera, (8 extrato alcoólico de própolis 8% e cera e (9 extrato alcoólico de própolis 10% e cera. Os frutos foram mantidos sob refrigeração (10 ± 1 ºC e 90 ± 5% umidade relativa, sendo avaliados a cada três dias durante 15 dias

  10. Preliminary evaluation of an aqueous wax emulsion for controlled-release coating.

    Science.gov (United States)

    Walia, P S; Stout, P J; Turton, R

    1998-02-01

    The purpose of this work was to evaluate the use of an aqueous carnauba wax emulsion (Primafresh HS, Johnson Wax) in a spray-coating process. This involved assessing the effectiveness of the wax in sustaining the release of the drug, theophylline. Second, the process by which the drug was released from the wax-coated pellets was modeled. Finally, a method to determine the optimum blend of pellets with different wax thicknesses, in order to yield a zero-order release profile of the drug, was addressed. Nonpareil pellets were loaded with theophylline using a novel powder coating technique. These drug-loaded pellets were then coated with different levels of carnauba wax in a 6-in. diameter Plexiglas fluid bed with a 3.5-in. diameter Wurster partition. Drug release was measured using a spin-filter dissolution device. The study resulted in continuous carnauba wax coatings which showed sustained drug release profile characteristics typical of a barrier-type, diffusion-controlled system. The effect of varying wax thickness on the release profiles was investigated. It was observed that very high wax loadings would be required to achieve long sustained-release times. The diffusion model, developed to predict the release of the drug, showed good agreement with the experimental data. However, the data exhibited an initial lag-time for drug release which could not be predicted a priori based on the wax coating thickness. A method of mixing pellets with different wax thicknesses was proposed as a way to approximate zero-order release.

  11. Bacterial decolorization and detoxification of black liquor from rayon grade pulp manufacturing paper industry and detection of their metabolic products.

    Science.gov (United States)

    Chandra, Ram; Abhishek, Amar; Sankhwar, Monica

    2011-06-01

    This study deals with the decolorization of black liquor (BL) by isolated potential bacterial consortium comprising Serratia marcescens (GU193982), Citrobacter sp. (HQ873619) and Klebsiella pneumoniae (GU193983). The decolorization of BL was studied by using the different nutritional as well as environmental parameters. In this study, result revealed that the ligninolytic activities were found to be growth associated and the developed bacterial consortium was efficient for the reduction of COD, BOD and color up to 83%, 74% and 85%, respectively. The HPLC analysis of degraded samples of BL has shown the reduction in peak area compared to control. Further, the GC-MS analysis showed that, most of the compounds detected in control were diminished after bacterial treatment while, formic acid hydrazide, 4-cyclohexane-1,2-dicarboxylic acid, carbamic acid, 1,2-benzenedicarboxylic acid and erythropentanoic acid were found as new metabolites. Further, the seed germination test using Phaseolus aureus has supported the detoxification of bacterial decolorized BL. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Bacterial community structure and variation in a full-scale seawater desalination plant for drinking water production

    NARCIS (Netherlands)

    Belila, A.; El-Chakhtoura, J.; Otaibi, N.; Muyzer, G.; Gonzalez-Gil, G.; Saikaly, P.E.; van Loosdrecht, M.C.M.; Vrouwenvelder, J.S.

    2016-01-01

    Microbial processes inevitably play a role in membrane-based desalination plants, mainly recognized as membrane biofouling. We assessed the bacterial community structure and diversity during different treatment steps in a full-scale seawater desalination plant producing 40,000 m3/d of drinking

  13. Establishing very long-chain fatty alcohol and wax ester biosynthesis in Saccharomyces cerevisiae.

    Science.gov (United States)

    Wenning, Leonie; Yu, Tao; David, Florian; Nielsen, Jens; Siewers, Verena

    2017-05-01

    Wax esters (WEs) are neutral lipids and can be used for a broad range of commercial applications, including personal care products, lubricants, or coatings. They are synthesized by enzymatic reactions catalyzed by a fatty acyl reductase (FAR) and a wax ester synthase (WS). At present, commercially used WEs are mainly isolated from Simmondsia chinensis (jojoba), but the high extraction costs and limited harvest areas constrain their use. The use of FARs in combination with different WSs to achieve a synthesis of jojoba-like WEs in bacteria and yeast has been reported previously, but the products were restricted to C28-C36 WEs. These rather short WEs make up only a very small percentage of the total WEs in natural jojoba oil. The synthesis of longer chain WEs (up to C44) in Saccharomyces cerevisiae has so far only been achieved after substrate feeding. Here we identified new routes for producing very long-chain fatty alcohols (VLCFOHs) up to a chain length of C22 by heterologous expression of a FAR derived from Apis mellifera (AmFAR1) or Marinobacter aquaeolei VT8 (Maqu_2220) in S. cerevisiae and achieved maximum yields of 3.22 ± 0.36 mg/g cell dry weight (CDW) and 7.84 ± 3.09 mg/g CDW, respectively, after 48 h. Moreover, we enabled the synthesis of jojoba-like WEs up to a chain length of C42, catalyzed by a combination of Maqu_2220 together with the WS from S. chinensis (SciWS) and the S. cerevisiae elongase Elo2p, with a maximum yield of 12.24 ± 3.35 mg/g CDW after 48 h. Biotechnol. Bioeng. 2017;114: 1025-1035. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Analysis of sorghum wax and carnauba wax by reversed phase liquid chromatography mass spectrometry

    Science.gov (United States)

    Sorghum is a genus in the grass family, which is used for both grain and forage production throughout the world. In the United States, sorghum grain is predominantly used as livestock feed, and in ethanol production. In recent years however, sorghum grain has been investigated for other industrial a...

  15. BraLTP1, a lipid transfer protein gene involved in epicuticular wax deposition, cell proliferation and flower development in Brassica napus.

    Directory of Open Access Journals (Sweden)

    Fang Liu

    Full Text Available Plant non-specific lipid transfer proteins (nsLTPs constitute large multigene families that possess complex physiological functions, many of which remain unclear. This study isolated and characterized the function of a lipid transfer protein gene, BraLTP1 from Brassica rapa, in the important oilseed crops Brassica napus. BraLTP1 encodes a predicted secretory protein, in the little known VI Class of nsLTP families. Overexpression of BnaLTP1 in B. napus caused abnormal green coloration and reduced wax deposition on leaves and detailed wax analysis revealed 17-80% reduction in various major wax components, which resulted in significant water-loss relative to wild type. BnaLTP1 overexpressing leaves exhibited morphological disfiguration and abaxially curled leaf edges, and leaf cross-sections revealed cell overproliferation that was correlated to increased cytokinin levels (tZ, tZR, iP, and iPR in leaves and high expression of the cytokinin biosynthsis gene IPT3. BnaLTP1-overexpressing plants also displayed morphological disfiguration of flowers, with early-onset and elongated carpel development and outwardly curled stamen. This was consistent with altered expression of a a number of ABC model genes related to flower development. Together, these results suggest that BraLTP1 is a new nsLTP gene involved in wax production or deposition, with additional direct or indirect effects on cell division and flower development.

  16. Soil water stress affects both cuticular wax content and cuticle-related gene expression in young saplings of maritime pine (Pinus pinaster Ait).

    Science.gov (United States)

    Le Provost, Grégoire; Domergue, Frédéric; Lalanne, Céline; Ramos Campos, Patricio; Grosbois, Antoine; Bert, Didier; Meredieu, Céline; Danjon, Frédéric; Plomion, Christophe; Gion, Jean-Marc

    2013-07-01

    The cuticle is a hydrophobic barrier located at the aerial surface of all terrestrial plants. Recent studies performed on model plants, such as Arabidopsis thaliana, have suggested that the cuticle may be involved in drought stress adaptation, preventing non-stomatal water loss. Although forest trees will face more intense drought stresses (in duration and intensity) with global warming, very few studies on the role of the cuticle in drought stress adaptation in these long-lived organisms have been so far reported. This aspect was investigated in a conifer, maritime pine (Pinus pinaster Ait.), in a factorial design with two genetic units (two half-sib families with different growth rates) and two treatments (irrigated vs non-irrigated), in field conditions. Saplings were grown in an open-sided greenhouse and half were irrigated three times per week for two growing seasons. Needles were sampled three times per year for cuticular wax (composition and content) and transcriptome (of 11 genes involved in cuticle biosynthesis) analysis. Non-irrigated saplings (i) had a higher cuticular wax content than irrigated saplings and (ii) overexpressed most of the genes studied. Both these trends were more marked in the faster growing family. The higher cuticular wax content observed in the non-irrigated treatment associated with strong modifications in products from the decarbonylation pathway suggest that cuticular wax may be involved in drought stress adaptation in maritime pine. This study provides also a set of promising candidate genes for future forward genetic studies in conifers.

  17. Composition of epicuticular wax on Prosopis glandulosa leaves

    International Nuclear Information System (INIS)

    Mayeux, H.S. Jr.; Wilkinson, R.E.

    1990-01-01

    Epicuticular wax on leaves of field-grown honey mesquite (Prosopis glandulosa Torr.) trees consisted of 35% esters, 32% alkanes, 25% free fatty alcohols, and 7% free fatty acids. Aldehydes were present in very low concentrations. The number of carbon atoms (C n ) of alkanes ranged from 25 to 31, with a maximum (57%) at 29. Esters consisted of fatty acids with C n of 16, 18, and 20, with most (70%) at 18 and fatty alcohols with C n of 24-32. The C n of free fatty alcohols and free fatty acids also ranged from 24 to 32. Only primary alcohols were present. Immediately after exposure of glasshouse-grown seedlings to 14 CO 2 for 4 h, 60% of the recovered 14 C was incorporated into free fatty acids; the percentage decreased progressively to 18% 8 h after exposure and remained stable thereafter. The proportion of 14 C in free fatty alcohols increased from ca. 12% immediately after exposure to 14 CO 2 to 55% at 8 h. Little 14 C was associated with other wax components over the 24-h period; 3% or less was incorporated into alkanes

  18. Characterisation of wax works of art by gas chromatographic procedures.

    Science.gov (United States)

    Regert, M; Langlois, J; Colinart, S

    2005-10-14

    To identify the various natural and synthetic substances used by sculptors at the end of the 19th century, several contemporary reference samples were investigated by high temperature gas chromatography (HT GC) and HT GC-MS. Using specific chromatographic conditions and minimising sample preparation, we could separate, detect and identify a wide range of biomolecular markers covering a great variety of molecular weights and volatilities, with a minimum amount of sample, in a single run. Beeswax, spermaceti, carnauba, candellila and Japan waxes as well as pine resin derivatives, animal fats, paraffin, ozokerite and stearin, used as additives in wax works of art, were chemically investigated. In the case of low volatile compounds, transbutylation was performed. The structure of long-chain esters of spermaceti was elucidated for the first time by HT GC-MS analysis. Such a method was then carried out on 10 samples collected on a statuette of Junon by Antoine-Louis Barye (Louvre Museum, Paris, France) and on a sculpture by Aimé-Jules Dalou (Musée de la Révolution Française, Vizille, France). The analytical results obtained provide new data on the complex recipes elaborated by sculptors at the end of the 19th century.

  19. Inverse gradients in leaf wax δD and δ13C values along grass blades of Miscanthus sinensis: implications for leaf wax reproduction and plant physiology.

    Science.gov (United States)

    Gao, Li; Huang, Yongsong

    2013-06-01

    Compound specific hydrogen and carbon isotopic ratios of higher plant leaf waxes have been extensively used in paleoclimate and paleoenvironmental reconstructions. However, studies so far have focused on the comparison of leaf wax isotopic differences in bulk leaf samples between different plant species. We sampled three different varieties of tall grasses (Miscanthus sinensis) in six segments from base to tip and determined hydrogen and carbon isotopic ratios of leaf waxes, as well as hydrogen and oxygen isotopic ratios of leaf water samples. We found an increasing, base-to-tip hydrogen isotopic gradient along the grass blades that can probably be attributed to active leaf wax regeneration over the growth season. Carbon isotopic ratios, on the other hand, show opposite trends to hydrogen isotopic ratios along the grass blades, which may reflect different photosynthetic efficiencies at different blade locales.

  20. An operon for production of bioactive gibberellin A4 phytohormone with wide distribution in the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola.

    Science.gov (United States)

    Nagel, Raimund; Turrini, Paula C G; Nett, Ryan S; Leach, Jan E; Verdier, Valérie; Van Sluys, Marie-Anne; Peters, Reuben J

    2017-05-01

    Phytopathogens have developed elaborate mechanisms to attenuate the defense response of their host plants, including convergent evolution of complex pathways for production of the GA phytohormones, which were actually first isolated from the rice fungal pathogen Gibberella fujikuroi. The rice bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc) has been demonstrated to contain a biosynthetic operon with cyclases capable of producing the universal GA precursor ent-kaurene. Genetic (knock-out) studies indicate that the derived diterpenoid serves as a virulence factor for this rice leaf streak pathogen, serving to reduce the jasmonic acid-mediated defense response. Here the functions of the remaining genes in the Xoc operon are elucidated and the distribution of the operon in X. oryzae is investigated in over 100 isolates. The Xoc operon leads to production of the bioactive GA 4 , an additional step beyond production of the penultimate precursor GA 9 mediated by the homologous operons recently characterized from rhizobia. Moreover, this GA biosynthetic operon was found to be widespread in Xoc (> 90%), but absent in the other major X. oryzae pathovar. These results indicate selective pressure for production of GA 4 in the distinct lifestyle of Xoc, and the importance of GA to both fungal and bacterial pathogens of rice. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  1. Nitrous oxide production and mRNA expression analysis of nitrifying and denitrifying bacterial genes under floodwater disappearance and fertilizer application.

    Science.gov (United States)

    Riya, Shohei; Takeuchi, Yuki; Zhou, Sheng; Terada, Akihiko; Hosomi, Masaaki

    2017-06-01

    A pulse of nitrous oxide (N 2 O) emission has been observed following the disappearance of floodwater by drainage. However, its mechanism is not well understood. We conducted a column study to clarify the mechanism for N 2 O production during floodwater disappearance by using a microsensor and determining the bacterial gene expression. An increase in N 2 O flux was observed following floodwater disappearance after the addition of NH 4 + , with a corresponding increase in the concentrations of NO 3 - and dissolved N 2 O in the oxic and anoxic soil layers, respectively. The transcription level of the bacterial amoA mRNA did not change, while that of nirK mRNA increased sharply after an hour of floodwater disappearance. An additional anoxic soil slurry experiment demonstrated that the addition of NO 3 - induced the expression of nirK gene and caused a concomitant increase in N 2 O production. These findings suggest that NO 3 - production in the oxic layers is important as it provides a substrate and induces the synthesis of denitrification enzymes in the anoxic layer during N 2 O production.

  2. Changes in Cuticular Wax Composition of Two Blueberry Cultivars during Fruit Ripening and Postharvest Cold Storage.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Chen, Hangjun; Wu, Weijie; Fang, Xiangjun

    2018-03-21

    Cuticular wax plays an important role for the quality of blueberry fruits. In this study, the cuticular wax composition of two blueberry cultivars, 'Legacy' ( Vaccinium corymbosum) and 'Brightwell' ( Vaccinium ashei), was examined during fruit ripening and postharvest cold storage. The results showed that wax was gradually deposited on the epidermis of blueberry fruits and the content of major wax compounds, except that for diketones, increased significantly during fruit ripening. The total wax content was 2-fold greater in 'Brightwell' blueberries than that in 'Legacy' blueberries during fruit ripening. The total wax content of both cultivars decreased during 30 days of storage at 4 °C, and the variation of cuticular wax composition was cultivar-dependent. The content of diketones decreased significantly in 'Legacy' blueberries, while the content of triterpenoids and aliphatic compounds showed different fold changes in 'Brightwell' blueberries after 30 days of storage at 4 °C. Overall, our study provided a quantitative and qualitative overview of cuticular wax compounds of blueberry fruits during ripening and postharvest cold storage.

  3. Development and Performance Evaluation of Image-Based Robotic Waxing System for Detailing Automobiles.

    Science.gov (United States)

    Lin, Chi-Ying; Hsu, Bing-Cheng

    2018-05-14

    Waxing is an important aspect of automobile detailing, aimed at protecting the finish of the car and preventing rust. At present, this delicate work is conducted manually due to the need for iterative adjustments to achieve acceptable quality. This paper presents a robotic waxing system in which surface images are used to evaluate the quality of the finish. An RGB-D camera is used to build a point cloud that details the sheet metal components to enable path planning for a robot manipulator. The robot is equipped with a multi-axis force sensor to measure and control the forces involved in the application and buffing of wax. Images of sheet metal components that were waxed by experienced car detailers were analyzed using image processing algorithms. A Gaussian distribution function and its parameterized values were obtained from the images for use as a performance criterion in evaluating the quality of surfaces prepared by the robotic waxing system. Waxing force and dwell time were optimized using a mathematical model based on the image-based criterion used to measure waxing performance. Experimental results demonstrate the feasibility of the proposed robotic waxing system and image-based performance evaluation scheme.

  4. Gluconeogenesis from Storage Wax in the Cotyledons of Jojoba Seedlings 1

    Science.gov (United States)

    Moreau, Robert A.; Huang, Anthony H. C.

    1977-01-01

    The cotyledons of jojoba (Simmondsia chinensis) seeds contained 50 to 60% of their weight as intracellular wax esters. During germination there was a gradual decrease in the wax content with a concomitant rise in soluble carbohydrates, suggesting that the wax played the role of a food reserve. Thin layer chromatography revealed that both the fatty alcohol and fatty acid were metabolized. The disappearance of wax was matched with an increase of catalase, a marker enzyme of the gluconeogenic process in other fatty seedlings. Subcellular organelles were isolated by sucrose gradient centrifugation from the cotyledons at the peak stage of germination. The enzymes of the β oxidation of fatty acid and of the glyoxylate cycle were localized in the glyoxysomes but not in the mitochondria. The glyoxysomes had specific activities of individual enzymes similar to those of the castor bean glyoxysomes. An active alkaline lipase was detected in the wax bodies at the peak stage of germination but not in the ungerminated seeds. No lipase was detected in glyoxysomes or mitochondria. After the wax in the wax bodies had been extracted with diethyl ether, the organelle membrane was isolated and it still retained the alkaline lipase. The gluconeogenesis from wax in the jojoba seedling appears to be similar, but with modification, to that from triglyceride in other fatty seedlings. Images PMID:16660087

  5. Effect of soil moisture management on the quality of wax apple | Lin ...

    African Journals Online (AJOL)

    Wax apple (Syzygium samarngense Merr.et Perry) was one of the economically planted fruits in Taiwan. This research was conducted to evaluate the effects of different soil moisture management on increasing wax apple quality. It was preceded at two different soil properties (shallow soil and alluvial soil) in Pingtung, ...

  6. Morphology and accumulation of epicuticular wax on needles of Douglas-fir (Pseudotsuga menziesii var. menziesii)

    Science.gov (United States)

    Constance A. Harrington; William C. Carlson

    2015-01-01

    Past studies have documented differences in epicuticular wax among several tree species but little attention has been paid to changes in accumulation of foliar wax that can occur during the year. We sampled current-year needles from the terminal shoots of Douglas-fir (Pseudotsuga menziesii var. menziesii) in late June/early...

  7. Composition and morphology of cuticular wax in blueberry (Vaccinium spp.) fruits.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Cao, Shifeng; Fang, Xiangjun; Chen, Hangjun; Xiao, Shangyue

    2017-03-15

    The chemical composition and morphology of cuticular wax in mature fruit of nine blueberry cultivars were investigated using gas chromatography-mass spectrometry (GC-MS) and scanning electron microscope (SEM). Triterpenoids and β-diketones were the most prominent compounds, accounting for on average 64.2% and 16.4% of the total wax, respectively. Ursolic or oleanolic acid was identified as the most abundant triterpenoids differing in cultivars. Two β-diketones, hentriacontan-10,12-dione and tritriacontan-12,14-dione, were detected in cuticular wax of blueberry fruits for the first time. Notably, hentriacontan-10,12-dione and tritriacontan-12,14-dione were only detected in highbush (V. corymbosum) and rabbiteye (V. ashei) blueberries, respectively. The results of SEM showed that a large amount of tubular wax deposited on the surface of blueberry fruits. There was no apparent difference in wax morphology among the nine cultivars. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effects of cuticular wax on the postharvest quality of blueberry fruit.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Chen, Hangjun; Fang, Xiangjun; Zheng, Yonghua

    2018-01-15

    The blueberry fruit has a light-blue appearance because its blue-black skin is covered with a waxy bloom. This layer is easily damaged or removed during fruit harvesting and postharvest handling. We investigated the effects of wax removal on the postharvest quality of blueberry fruit and their possible mechanisms. The removal of natural wax on the fruit was found to accelerate the postharvest water loss and decay, reduce the sensory and nutritional qualities, and shorten the shelf-life. Wax removal decreased the activities of antioxidant enzymes and contents of antioxidants, and accelerated accumulation of ROS and lipid peroxidation, especially at the later period of storage. Moreover, the organellar membrane structure was disrupted in fruit with wax removed. These results indicate that cuticular wax plays an important role in maintaining the postharvest quality and delaying fruit senescence. The results should improve our understanding for better preservation of postharvest quality of blueberry fruit. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Bacterial production, glucosidase activity and particle-associated carbohydrates in Dona Paula bay, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Bhaskar, P.V.; Bhosle, N.B.

    theaquaticenvironmentcontributingupto80%ofthedissolvedand 5–25% of the particulate organic carbon (Decho,1990; Benner et al., 1992; Biersmith and Benner, 1998). Although free and combined amino acids are the most preferred carbon and nitrogen source 1. Introduction... of bulk bacterial biomass and enzyme activity is varyingly attributed to particle-associated bacteria and free-living bacteria (Palumbo et al., 1984; Griffith et al., 1990; Karner and Herndl,1992; Bidle and Fletcher,1995). The enzymatic breakdown...

  10. N-Acetyl-l-Cysteine Affects Growth, Extracellular Polysaccharide Production, and Bacterial Biofilm Formation on Solid Surfaces

    OpenAIRE

    Olofsson, Ann-Cathrin; Hermansson, Malte; Elwing, Hans

    2003-01-01

    N-Acetyl-l-cysteine (NAC) is used in medical treatment of patients with chronic bronchitis. The positive effects of NAC treatment have primarily been attributed to the mucus-dissolving properties of NAC, as well as its ability to decrease biofilm formation, which reduces bacterial infections. Our results suggest that NAC also may be an interesting candidate for use as an agent to reduce and prevent biofilm formation on stainless steel surfaces in environments typical of paper mill plants. Usi...

  11. Bio-paraffins: alternative products to petroleum paraffins; Bioparafinas: produtos alternativos as parafinas de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Anie Daniela Medeiros [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Hidrorrefino e Processos Especiais; Oliveira, Claudia Cristina Cardoso Calvano de; Carvalho, Ivone de Freitas; Silva, Danilo do Carmo Santos; Cruz, Valeria Senra da Silva [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Lubrificantes e Produtos Especiais]. E-mails: anie.lima, claudiacristina, ivone, danilosilva, vsenra@petrobras.com.br

    2007-04-15

    Market trends and social and environmental issues encouraged the vegetal wax presence in the world-wide paraffin market. This work presents the most commercialized vegetal waxes, soy and pal, comparing their physicochemical characteristics and their applicability with the paraffins obtained from petroleum. It also presents a characterization of the carnauba wax, produced exclusively in Brazil and a comparison with paraffins from petroleum. The carnauba wax is an alternative product, with good applicability as a substitute for waxes from petroleum or a petroleum/vegetal mixture. The characteristics of palm and soy waxes show the possible application in candles, cosmetics, foods and others industries. Brazil, having a great agricultural potential, represents a source of vegetal wax that could be use to meet the market demands. (author)

  12. 76 FR 773 - Petroleum Wax Candles From the People's Republic of China: Continuation of Antidumping Duty Order

    Science.gov (United States)

    2011-01-06

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-504] Petroleum Wax Candles From... Trade Commission (``ITC'') that revocation of the antidumping duty order on petroleum wax candles from... order on petroleum wax candles from the PRC pursuant to section 751(c)(2) of the Tariff Act of 1930, as...

  13. Selection of potent bacterial strain for over-production of PHB by using low cost carbon source for eco-friendly bioplastics

    Directory of Open Access Journals (Sweden)

    Rahat Abdul Rehman

    2015-11-01

    Full Text Available Background: The microbial PHB production is a promising tool for the plastic industry for the synthesis of environmental friendly, biodegradable plastic in contrast to the conventional petro-chemical based non-degradable plastics. The selection of potent bacterial strains, inexpensive carbon source, efficient fermentation and recovery processes are important aspects that were taken into account during this study. Methods: Different bacterial strains i.e. Bacillus Spp, P. putida and P. fluorescens were screened for maximum PHB production. Under media optimization, various carbon and nitrogen sources (alone or in combination were used to achieve the maximum PHB production. Finally the degradation tests of the PHB sheet were also performed to test its biodegradability potential. Results: Shake flask studies have shown the PHB concentrations upto 7.02, 4.50 and 34.4 mg/g of dry cell mass of P. putida, P. fluorescens and Bacillus Spp. respectively. Almost same results were observed at laboratory scale production of PHB in 10 L fermenter i.e. 6.28, 6.23 and 39.5 mg/g of dry cell mass by P. putida, P. fluorescens and Bacillus Spp. respectively. On the basis of these observations, Bacillus Spp. was chosen for laboratory scale PHB production. Corn steep liquor (4% was chosen as the best medium to achieve the highest PHB contents. Isolated PHB has shown biodegradation in soil up to 86.7% at 37oC. Conclusion: The Bacillus Spp. Proved to be the best strain for PHB production on only 4% CSL which is cheapest and easily available.

  14. Marginal adaptation of four inlay casting waxes on stone, titanium, and zirconia dies.

    Science.gov (United States)

    Michalakis, Konstantinos X; Kapsampeli, Vassiliki; Kitsou, Aikaterini; Kirmanidou, Yvone; Fotiou, Anna; Pissiotis, Argirios L; Calvani, Pasquale Lino; Hirayama, Hiroshi; Kudara, Yukio

    2014-07-01

    Different inlay casting waxes do not produce copings with satisfactory marginal accuracy when used on different die materials. The purpose of this study was to evaluate the marginal accuracy of 4 inlay casting waxes on stone dies and titanium and zirconia abutments and to correlate the findings with the degree of wetting between the die specimens and the inlay casting waxes. The inlay casting waxes tested were Starwax (Dentaurum), Unterziehwachs (Bredent), SU Esthetic wax (Schuler), and Sculpturing wax (Renfert). The marginal opening of the waxes was measured with a stereomicroscope on high-strength stone dies and on titanium and zirconia abutments. Photographic images were obtained, and the mean marginal opening for each specimen was calculated. A total of 1440 measurements were made. Wetting between die materials and waxes was determined after fabricating stone, titanium, and zirconia rectangular specimens. A calibrated pipette was used to place a drop of molten wax onto each specimen. The contact angle was calculated with software after an image of each specimen had been made with a digital camera. Collected data were subjected to a 2-way analysis of variance (α=.05). Any association between marginal accuracy and wetting of different materials was found by using the Pearson correlation. The wax factor had a statistically significant effect both on the marginal discrepancy (F=158.31, P<.001) and contact angle values (F=68.09, P<.001). A statistically significant effect of the die material factor both on the marginal adaptation (F=503.47, P<.001) and contact angle values (F=585.02, P<.001) was detected. A significant correlation between the marginal accuracy and the contact angle values (Pearson=0.881, P=.01) was also found. Stone dies provided wax copings with the best marginal integrity, followed by titanium and zirconia abutments. Unterziehwachs (Bredent), wax produced the best marginal adaptation on different die materials. A significant correlation was found

  15. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  16. Abiotic condensation synthesis of glyceride lipids and wax esters under simulated hydrothermal conditions.

    Science.gov (United States)

    Rushdi, Ahmed I; Simoneit, Bernd R T

    2006-04-01

    Precursor compounds for abiotic proto cellular membranes are necessary for the origin of life. Amphipathic compounds such as fatty acids and acyl glycerols are important candidates for micelle/bilayer/vesicle formation. Two sets of experiments were conducted to study dehydration reactions of model lipid precursors in aqueous media to form acyl polyols and wax esters, and to evaluate the stability and reactions of the products at elevated temperatures. In the first set, mixtures of n-nonadecanoic acid and ethylene glycol in water, with and without oxalic acid, were heated at discrete temperatures from 150 ( composite function)C to 300 ( composite function)C for 72 h. The products were typically alkyl alkanoates, ethylene glycolyl alkanoates, ethylene glycolyl bis-alkanoates and alkanols. The condensation products had maximum yields between 150 ( composite function)C and 250 ( composite function)C, and were detectable and thus stable under hydrothermal conditions to temperatures acid and glycerol were heated using the same experimental conditions, with and without oxalic acid, between 100 ( composite function)C and 250 ( composite function)C. The main condensation products were two isomers each of monoacylglycerols and diacylglycerols at all temperatures, as well as minor amounts of the fatty acid anhydride and methyl ester. The yield of glyceryl monoheptanoates generally increased with increasing temperature and glyceryl diheptanoates decreased noticeably with increasing temperature. The results indicate that condensation reactions and abiotic synthesis of organic lipid compounds under hydrothermal conditions occur easily, provided precursor concentrations are sufficiently high.

  17. Assessing the impact of lyophilization process in production of implants based on the bacterial cellulose using Raman spectroscopy method

    International Nuclear Information System (INIS)

    Timchenko, E V; Timchenko, P E; Pisareva, E V; Vlasov, M Yu; Revin, V V; Klenova, N A; Asadova, A A

    2017-01-01

    In this article we present the research results of lyophilization process influence on the composition of hybrid materials based on the bacterial cellulose (BC) using Raman spectroscopy method. As an object of research was used BC, as well as hybrids based on it, comprising the various combinations of hydroxyapatite (HAP) and collagen. Our studies showed that during the lyophilization process changes the ratio of the individual components. It was found that for samples hybrid based on BC with addition of HAP occurs increase of PO 4 3- peak intensity in the region 956 cm -1 with decreasing width, which indicates a change in the degree of HAP crystallinity. (paper)

  18. Assessing the impact of lyophilization process in production of implants based on the bacterial cellulose using Raman spectroscopy method

    Science.gov (United States)

    Timchenko, E. V.; Timchenko, P. E.; Pisareva, E. V.; Vlasov, M. Yu; Revin, V. V.; Klenova, N. A.; Asadova, A. A.

    2017-01-01

    In this article we present the research results of lyophilization process influence on the composition of hybrid materials based on the bacterial cellulose (BC) using Raman spectroscopy method. As an object of research was used BC, as well as hybrids based on it, comprising the various combinations of hydroxyapatite (HAP) and collagen. Our studies showed that during the lyophilization process changes the ratio of the individual components. It was found that for samples hybrid based on BC with addition of HAP occurs increase of PO4 3- peak intensity in the region 956 cm-1 with decreasing width, which indicates a change in the degree of HAP crystallinity.

  19. Bacterial prostatitis.

    Science.gov (United States)

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  20. The effect of the environment on the structure, quantity and composition of spruce needle wax

    International Nuclear Information System (INIS)

    Guenthardt-Goerg, M.S.

    1994-01-01

    The tubular structure (10-nonacosanol), as formed in spring on the wax surface of new spruce needles (Picea abies (L.)Karst.), or as regenerated on previous-year needles, becomes gradually fused and flattened in relation to needle exposure, particularly wind and rain. Structural flattening does not necessarily imply changes in wax quantity, composition or lead to changes in needle transpiration or photosynthesis, and was approximately reproduced by bathing excised twigs in water (with pH having little effect). In 4-year-old plants of one clone planted out at a Swiss plateau and alpine sites, changes in wax structure were similar to those found in mature trees. No such changes were found in plants with O 3 , SO 2 , ambient air, charcoal-filtered air, or in plants grown outside the chambers but shielded from rain. Area-related needle wax quantity in mature trees differed between the two sites, but did not differ in young plants under different treatments (fumigation or planted out at the sites). Minor differences in wax composition, however, were found to be related to the ozone dose of the fumigation or the ambient ozone dose at the sites. In each needle wax sample, 68 compounds grouped into 12 constituent classes were quantified. The quantity of the individual substituent classes varied among wax samples from genetically different mature trees at the two sites in a tree-specific way. Variation of these quantities was not larger than among young cloned plants after different treatments. (orig.)

  1. Anatomical models and wax Venuses: art masterpieces or scientific craft works?

    Science.gov (United States)

    Ballestriero, R

    2010-02-01

    The art of wax modelling has an ancient origin but rose to prominence in 14th century Italy with the cult of votive artefacts. With the advent of Neoclassicism this art, now deemed repulsive, continued to survive in a scientific environment, where it flourished in the study of normal and pathological anatomy, obstetrics, zoology and botany. The achievement of having originated the creation of anatomical models in coloured wax must be ascribed to a joint effort undertaken by the Sicilian wax modeller Gaetano Giulio Zumbo and the French surgeon Guillaume Desnoues in the late 17th century. Interest in anatomical wax models spread throughout Europe during the 18th century, first in Bologna with Ercole Lelli, Giovanni Manzolini and Anna Morandi, and then in Florence with Felice Fontana and Clemente Susini. In England, the art of anatomical ceroplastics was brought to London from Florence by the sculptor Joseph Towne. Throughout the centuries many anatomical artists preferred this material due to the remarkable mimetic likeness obtained, far surpassing any other material. Independent of the material used, whether wood, wax or clay, anatomical models were always considered merely craft works confined to hospitals or faculties of medicine and have survived to this day only because of their scientific interest. Italian and English waxes are stylistically different but the remarkable results obtained by Susini and Towne, and the fact that some contemporary artists are again representing anatomical wax bodies in their works, makes the border that formerly separated art and craft indistinguishable.

  2. Phase Change Insulation for Energy Efficiency Based on Wax-Halloysite Composites

    International Nuclear Information System (INIS)

    Zhao, Yafei; Thapa, Suvhashis; Weiss, Leland; Lvov, Yuri

    2014-01-01

    Phase change materials (PCMs) have gained extensive attention in thermal energy storage. Wax can be used as a PCM in solar storage but it has low thermal conductivity. Introducing 10% halloysite admixed into wax yields a novel composite (wax-halloysite) which has a thermal conductivity of 0.5 W/mK. To increase the base conductivity, graphite and carbon nanotubes were added into the PCM composite improving its thermal energy storage. Thermal conductivity of wax-halloysite-graphite (45/45/10%) composite showed increased conductivity of 1.4 W/mK (3 times higher than the base wax-halloysite composite). Wax- halloysite-graphite-carbon nanotubes (45/45/5/5%) composite showed conductivity of 0.85 W/mK while maintaining the original shape perfectly until 91 °C (above the original wax melting point). Thermal conductivity can be further increased with higher doping of carbon nanotubes. This new composites are promising heat storage material due to good thermal stability, high thermal/electricity conductivity and ability to preserve its shape during phase transitions

  3. Development of formulations and processes to incorporate wax oleogels in ice cream.

    Science.gov (United States)

    Zulim Botega, Daniele C; Marangoni, Alejandro G; Smith, Alexandra K; Goff, H Douglas

    2013-12-01

    The objective of this study was to investigate the influence of emulsifiers, waxes, fat concentration, and processing conditions on the application of wax oleogel to replace solid fat content and create optimal fat structure in ice cream. Ice creams with 10% or 15% fat were formulated with rice bran wax (RBW), candelilla wax (CDW), or carnauba wax (CBW) oleogels, containing 10% wax and 90% high-oleic sunflower oil. The ice creams were produced using batch or continuous freezing processes. Transmission electron microscopy (TEM) and cryo-scanning electron microscopy were used to evaluate the microstructure of ice cream and the ultrastructure of oleogel droplets in ice cream mixes. Among the wax oleogels, RBW oleogel had the ability to form and sustain structure in 15% fat ice creams when glycerol monooleate (GMO) was used as the emulsifier. TEM images revealed that the high degree of fat structuring observed in GMO samples was associated with the RBW crystal morphology within the fat droplet, which was characterized by the growth of crystals at the outer edge of the droplet. Continuous freezing improved fat structuring compared to batch freezing. RBW oleogels established better structure compared to CDW or CBW oleogels. These results demonstrate that RBW oleogel has the potential to develop fat structure in ice cream in the presence of GMO and sufficiently high concentrations of oleogel. © 2013 Institute of Food Technologists®

  4. Structure of a bacterial glycoside hydrolase family 63 enzyme in complex with its glycosynthase product, and insights into the substrate specificity.

    Science.gov (United States)

    Miyazaki, Takatsugu; Ichikawa, Megumi; Yokoi, Gaku; Kitaoka, Motomitsu; Mori, Haruhide; Kitano, Yoshikazu; Nishikawa, Atsushi; Tonozuka, Takashi

    2013-09-01

    Proteins belonging to glycoside hydrolase family 63 (GH63) are found in bacteria, archaea and eukaryotes. Although the eukaryotic GH63 proteins have been identified as processing α-glucosidase I, the substrate specificities of the bacterial and archaeal GH63 proteins are not clear. Here, we converted a bacterial GH63 enzyme, Escherichia coli YgjK, to a glycosynthase to probe its substrate specificity. Two mutants of YgjK (E727A and D324N) were constructed, and both mutants showed glycosynthase activity. The reactions of E727A with β-D-glucosyl fluoride and monosaccharides showed that the largest amount of glycosynthase product accumulated when galactose was employed as an acceptor molecule. The crystal structure of E727A complexed with the reaction product indicated that the disaccharide bound at the active site was 2-O-α-D-glucopyranosyl-α-D-galactopyranose (Glc12Gal). A comparison of the structures of E727A-Glc12Gal and D324N-melibiose showed that there were two main types of conformation: the open and closed forms. The structure of YgjK adopted the closed form when subsite -1 was occupied by glucose. These results suggest that sugars containing the Glc12Gal structure are the most likely candidates for natural substrates of YgjK. © 2013 FEBS.

  5. Molecular diversity of bacterial communities from subseafloor rock samples in a deep-water production basin in Brazil.

    Science.gov (United States)

    von der Weid, Irene; Korenblum, Elisa; Jurelevicius, Diogo; Rosado, Alexandre Soares; Dino, Rodolfo; Sebastian, Gina Vasquez; Seldin, Lucy

    2008-01-01

    The deep subseafloor rock in oil reservoirs represents a unique environment in which a high oilcontamination and very low biomass can be observed. Sampling this environment has been a challenge owing to the techniques used for drilling and coring. In this study, the facilities developed by the Brazilian oil company PETROBRAS for accessing deep subsurface oil reservoirs were used to obtain rock samples at 2,822-2,828 m below the ocean floor surface from a virgin field located in the Atlantic Ocean, Rio de Janeiro. To address the bacterial diversity of these rock samples, PCR amplicons were obtained using the DNA from four core sections and universal primers for 16S rRNA and for APS reductase (aps) genes. Clone libraries were generated from these PCR fragments and 87 clones were sequenced. The phylogenetic analyses of the 16S rDNA clone libraries showed a wide distribution of types in the domain bacteria in the four core samples, and the majority of the clones were identified as belonging to Betaproteobacteria. The sulfate-reducing bacteria community could only be amplified by PCR in one sample, and all clones were identified as belonging to Gammaproteobacteria. For the first time, the bacterial community was assessed in such deep subsurface environment.

  6. Improvement of simultaneous Cr(VI) and phenol removal by an immobilised bacterial consortium and characterisation of biodegradation products.

    Science.gov (United States)

    Ontañon, Ornella M; González, Paola S; Barros, Germán G; Agostini, Elizabeth

    2017-07-25

    Microbial bioremediation emerged some decades ago as an eco-friendly technology to restore polluted sites. Traditionally, the search for microorganisms suitable for bioremediation has been based on the selection of isolated strains able to remove a specific type of pollutant. However, this strategy has now become obsolete, since co-pollution is a global reality. Thus, current studies attempt to find bacterial cultures capable of coping with a mixture of organic and inorganic compounds. In this sense, the bacterial consortium SFC 500-1 has demonstrated efficiency for Cr(VI) and phenol removal, both of which are found in many industrial wastewaters. In the present study, the ability of SFC 500-1 for simultaneous removal was improved through its entrapment in a Ca-alginate matrix. This strategy led to an increased removal of Cr(VI), which was partially reduced to Cr(III). Immobilised cells were able to tolerate and degrade phenol up to 1,500mg/l at high rates, forming catechol and cis,cis-muconate as oxidation intermediates. Successful removal potential through 5 cycles of reuse, as well as after long-term storage, was another important advantage of the immobilised consortium. These characteristics make SFC 500-1 an interesting system for potential application in the biotreatment of co-polluted effluents. Copyright © 2017. Published by Elsevier B.V.

  7. Accuracy of ringless casting and accelerated wax-elimination technique: a comparative in vitro study.

    Science.gov (United States)

    Prasad, Rahul; Al-Keraif, Abdulaziz Abdullah; Kathuria, Nidhi; Gandhi, P V; Bhide, S V

    2014-02-01

    The purpose of this study was to determine whether the ringless casting and accelerated wax-elimination techniques can be combined to offer a cost-effective, clinically acceptable, and time-saving alternative for fabricating single unit castings in fixed prosthodontics. Sixty standardized wax copings were fabricated on a type IV stone replica of a stainless steel die. The wax patterns were divided into four groups. The first group was cast using the ringless investment technique and conventional wax-elimination method; the second group was cast using the ringless investment technique and accelerated wax-elimination method; the third group was cast using the conventional metal ring investment technique and conventional wax-elimination method; the fourth group was cast using the metal ring investment technique and accelerated wax-elimination method. The vertical marginal gap was measured at four sites per specimen, using a digital optical microscope at 100× magnification. The results were analyzed using two-way ANOVA to determine statistical significance. The vertical marginal gaps of castings fabricated using the ringless technique (76.98 ± 7.59 μm) were significantly less (p castings fabricated using the conventional metal ring technique (138.44 ± 28.59 μm); however, the vertical marginal gaps of the conventional (102.63 ± 36.12 μm) and accelerated wax-elimination (112.79 ± 38.34 μm) castings were not statistically significant (p > 0.05). The ringless investment technique can produce castings with higher accuracy and can be favorably combined with the accelerated wax-elimination method as a vital alternative to the time-consuming conventional technique of casting restorations in fixed prosthodontics. © 2013 by the American College of Prosthodontists.

  8. Effects of bacterial lipopolysaccharide and X-irradiation on the production of colony-stimulating factor and the maintenance of granulopoiesis in bone marrow culture

    International Nuclear Information System (INIS)

    Izumi, H.; Miyanomae, T.; Tsurusawa, M.; Fujita, J.; Mori, K.

    1984-01-01

    Effects of bacterial lipopolysaccharide (LPS) and X-irradiation on CSF production and granulopoiesis in long-term bone marrow cultures were studied. Levels of colony-stimulating factor (CSF) increased soon after the refeeding of the culture, but the activity was undetectable at day 7. Addition of LPS induced a significant increase in CSF levels in the culture, followed by an elevated granulopoiesis. The increase in CSF levels was suppressed when culture medium that had been harvested at refeeding on day 7 was added. Although irradiation did not increase CSF production, granulopoiesis was markedly stimulated shortly after irradiation. Thus granulopoiesis in long-term bone marrow culture may also be regulated by humoral factors such as CSF, and the culture system may represent the in vivo response to haemopoietic stimuli. (author)

  9. Bacterial Vaginosis

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  10. Tectonic microplates in a wax model of sea-floor spreading

    International Nuclear Information System (INIS)

    Katz, Richard F; Ragnarsson, Rolf; Bodenschatz, Eberhard

    2005-01-01

    Rotating, growing microplates are observed in a wax analogue model of sea-floor spreading. Wax microplates are kinematically similar to sea-floor tectonic microplates in terms of spreading rate and growth rate. Furthermore, their spiral pseudofault geometry is quantitatively consistent with Schouten's oceanic microplate model. These results suggest that Schouten's edge-driven microplate model captures the kinematics of tectonic microplate evolution on Earth. Based on the wax observations, a theory for the nucleation of overlapping spreading centres, the precursors of tectonic microplates, is developed

  11. Caffeine and theobromine in epicuticular wax of Ilex paraguariensis A. St.-Hil.

    Science.gov (United States)

    Athayde, M L; Coelho, G C; Schenkel, E P

    2000-12-01

    Caffeine and theobromine were identified and quantified in leaf epicuticular waxes of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae). The total epicuticular leaf wax content was ca. 0.5% on average of dry leaf weight. Epicuticular caffeine and theobromine contents varied from 0.16 to 127.6 microg/mg and from 0 to 9.5 microg/mg of wax, respectively. For some selected samples, the intracellular methylxanthine concentration was also determined. A positive correlation was found between inner and epicuticular caffeine contents.

  12. Particulate pollutants are capable to 'degrade' epicuticular waxes and to decrease the drought tolerance of Scots pine (Pinus sylvestris L.).

    Science.gov (United States)

    Burkhardt, Juergen; Pariyar, Shyam

    2014-01-01

    Air pollution causes the amorphous appearance of epicuticular waxes in conifers, usually called wax 'degradation' or 'erosion', which is often correlated with tree damage symptoms, e.g., winter desiccation. Previous investigations concentrated on wax chemistry, with little success. Here, we address the hypothesis that both 'wax degradation' and decreasing drought tolerance of trees may result from physical factors following the deposition of salt particles onto the needles. Pine seedlings were sprayed with dry aerosols or 50 mM solutions of different salts. The needles underwent humidity changes within an environmental scanning electron microscope, causing salt expansion on the surface and into the epistomatal chambers. The development of amorphous wax appearance by deliquescent salts covering tubular wax fibrils was demonstrated. The minimum epidermal conductance of the sprayed pine seedlings increased. Aerosol deposition potentially 'degrades' waxes and decreases tree drought tolerance. These effects have not been adequately considered thus far in air pollution research. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Bacterial cells with improved tolerance to polyamines

    DEFF Research Database (Denmark)

    2017-01-01

    Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds.......Provided are bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as polyamines, and methods of preparing and using such bacterial cells for production of polyamines and other compounds....

  14. Bacterial cells with improved tolerance to polyols

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds.......The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds....

  15. Influence of Integrated Use of Inorganic fertiliser and Organic manures on Bacterial Wilt Incidence (WI) and Tuber Yield in Potato Production Systems in Southern Slopes of Mt. Kenya

    International Nuclear Information System (INIS)

    Mriithi, L.M.

    2002-01-01

    Bacterial wilt (BW) caused by Ralstonia solanacearum is one of the most damaging of potato (Solanum tuberosum L.) in Kenya and worldwide. In Kenya Potato tuber yield losses due to BW infection are estimated at 50-100%. Low soil fertility is also one of the most important constraints limiting potato production in central Kenya highlands. Farmers tackle this problem through use of inorganic fertilisers and organic manures, both of which amend the soil environment to influence bacterial wilt development. Undecomposed organic manures can also introduce the pathogen into a clean field. Between short rains 1999 and 2000, 10 on-farm researcher/farmer-designed and farmer-managed trials were done at Kianjuki catchment in Embu District. The objective was to use farmers' participatory research approach and select the most suitable organic and inorganic fertiliser combination(s) with lowest BWI and acceptable usable tuber yields. And also demonstrate use of some components of integrated disease management methods in reduction of disease incidence and spread. Seven treatments were proposed, presented to the farmers for discussion and the most relevant four were selected for evaluation . A newly released potato variety 'Asante' was planted during the short-rains 1999 and long rains 2000. BWI didn't;t result in significant differences between treatments but the tuber yields were significantly different in short-rains 1999 and 2000. During short-rains 2000, both BWI and tuber yields and unusable tubers differed significantly between treatments. The results confirmed that use of well-decomposed manures or manures from pathogen-free areas can be used in combination with inorganic fertilisers to improve soil fertility and potato tuber yields in smallholder farm without influencing BWI. Use of certified seed tubers in pathogen free fields and following recommendation field sanitation measures, resulted in apparently bacterial wilt free crop

  16. The Polyketide Components of Waxes and the Cer-cqu Gene Cluster Encoding a Novel Polyketide Synthase, the β-Diketone Synthase, DKS.

    Science.gov (United States)

    von Wettstein-Knowles, Penny

    2017-07-10

    The primary function of the outermost, lipophilic layer of plant aerial surfaces, called the cuticle, is preventing non-stomatal water loss. Its exterior surface is often decorated with wax crystals, imparting a blue-grey color. Identification of the barley Cer-c , -q and -u genes forming the 101 kb Cer-cqu gene cluster encoding a novel polyketide synthase-the β-diketone synthase (DKS), a lipase/carboxyl transferase, and a P450 hydroxylase, respectively, establishes a new, major pathway for the synthesis of plant waxes. The major product is a β-diketone (14,16-hentriacontane) aliphatic that forms long, thin crystalline tubes. A pathway branch leads to the formation of esterified alkan-2-ols.

  17. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas

    2011-11-04

    In this body of work we have been developing and characterizing paper based microfluidic fabrication technologies to produce low cost biological analysis. Specifically we investigated the performance of paper microfluidics that had been bonded using wax o

  18. Effect of matrix granulation and wax coating on the dissolution rates ...

    African Journals Online (AJOL)

    disintegrating) granules consisting of paracetamol (drug) and acrylatemethacrylate copolymer, a matrix forming material. The effect of coating the matrix granules with wax on the drug release profiles was also investigated. The objective was to ...

  19. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas

    2011-01-01

    In this body of work we have been developing and characterizing paper based microfluidic fabrication technologies to produce low cost biological analysis. Specifically we investigated the performance of paper microfluidics that had been bonded using wax o

  20. Development and Properties of a Wax Ester Hydrolase in the Cotyledons of Jojoba Seedlings 1

    Science.gov (United States)

    Huang, Anthony H. C.; Moreau, Robert A.; Liu, Kitty D. F.

    1978-01-01

    The activity of a wax ester hydrolase in the cotyledons of jojoba (Simmondsia chinensis) seedlings increased drastically during germination, parallel to the development of the gluconeogenic process. The enzyme at its peak of development was obtained in association with the wax body membrane, and its properties were studied. It had an optimal activity at alkaline pH (8.5-9). The apparent Km value for N-methylindoxylmyristate was 93 μM. It was stable at 40 C for 30 min but was inactivated at higher temperature. Various divalent cations and ethylenediaminetetraacetate had little effect on the activity. p-Chloromercuribenzoate was a strong inhibitor of the enzyme activity, and its effect was reversed by subsequent addition of dithiothreitol. It had a broad substrate specificity with highest activities on monoglycerides, wax esters, and the native substrate (jojoba wax). PMID:16660288

  1. Development and properties of a wax ester hydrolase in the cotyledons of jojoba seedlings.

    Science.gov (United States)

    Huang, A H; Moreau, R A; Liu, K D

    1978-03-01

    The activity of a wax ester hydrolase in the cotyledons of jojoba (Simmondsia chinensis) seedlings increased drastically during germination, parallel to the development of the gluconeogenic process. The enzyme at its peak of development was obtained in association with the wax body membrane, and its properties were studied. It had an optimal activity at alkaline pH (8.5-9). The apparent K(m) value for N-methylindoxylmyristate was 93 muM. It was stable at 40 C for 30 min but was inactivated at higher temperature. Various divalent cations and ethylenediaminetetraacetate had little effect on the activity. p-Chloromercuribenzoate was a strong inhibitor of the enzyme activity, and its effect was reversed by subsequent addition of dithiothreitol. It had a broad substrate specificity with highest activities on monoglycerides, wax esters, and the native substrate (jojoba wax).

  2. Printed wax masks for 254 nm deep-UV pattering of PMMA-based microfluidics

    KAUST Repository

    Fan, Yiqiang; Liu, Yang; Li, Huawei; Foulds, Ian G.

    2012-01-01

    This paper reports a new technique for masking deep-UV exposure of poly(methyl methacrylate) (PMMA) using a printed wax mask. This technique provides an inexpensive and bulk fabrication method for PMMA structures. The technique involves the direct

  3. "Wax bloom" on beeswax cultural heritage objects: exploring the causes of the phenomenon

    Czech Academy of Sciences Publication Activity Database

    Bartl, B.; Kobera, Libor; Drábková, K.; Ďurovič, M.; Brus, Jiří

    2015-01-01

    Roč. 53, č. 7 (2015), s. 509-513 ISSN 0749-1581 Institutional support: RVO:61389013 Keywords : 13-C NMR * wax bloom * efflorescence Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.226, year: 2015

  4. Bee waxes: a model of characterization for using as base simulator tissue in teletherapy with photons

    International Nuclear Information System (INIS)

    Silva, Rogerio Matias Vidal da; Souza, Divanizia do Nascimento

    2011-01-01

    This paper presents a model of characterization and selection of bee waxes which makes possible to certify the usage viability of that base simulator tissue in the manufacture of appropriated objects for external radiotherapy with mega volt photon beams. The work was divide into three stages, where was evaluated physical and chemical properties besides the aspects related to the capacity of beam attenuation. All the process was carefully accompanied related to the wax origin such as the bee specimen and the flora surrounding the beehives. The chemical composition of the waxes is similar to others simulators usually used in radiotherapy. The behavior of mass attenuation coefficient in the radiotherapeutic energy range is comparable to other simulators, and consequently to the soft tissue. The proposed model is efficient and allows the affirmative that the usage of determined bee wax as base simulator tissue is convenient

  5. A comparative evaluation of the marginal adaptation of a thermoplastic resin, a light cured wax and an inlay casting wax on stone dies: An in vitro study.

    Science.gov (United States)

    Gopalan, Reji P; Nair, Vivek V; Harshakumar, K; Ravichandran, R; Lylajam, S; Viswambaran, Prasanth

    2018-01-01

    Different pattern materials do not produce copings with satisfactory, marginal accuracy when used on stone dies at varying time intervals. The purpose of this study was to evaluate and compare the vertical marginal accuracy of patterns formed from three materials, namely, thermoplastic resin, light cured wax and inlay casting wax at three-time intervals of 1, 12, and 24 h. A master die (zirconia abutment mimicking a prepared permanent maxillary central incisor) and metal sleeve (direct metal laser sintering crown #11) were fabricated. A total of 30 stone dies were obtained from the master die. Ten patterns were made each from the three materials and stored off the die at room temperature. The vertical marginal gaps were measured using digital microscope at 1, 12, and 24 h after reseating with gentle finger pressure. The results revealed a significant statistical difference in the marginal adaptation of three materials at all the three-time intervals. Light cured wax was found to be most accurate at all time intervals, followed by thermoplastic resin and inlay casting wax. Furthermore, there was a significant difference between all pairs of materials. The change in vertical marginal gap from 1 to 24 h between thermoplastic resin and light cured wax was not statistically significant. The marginal adaptation of all the three materials used, was well within the acceptable range of 25-70 μm. The resin pattern materials studied revealed significantly less dimensional change than inlay casting wax on storage at 1, 12, and 24 h time intervals. They may be employed in situations where high precision and delayed investing is expected.

  6. Nanomaterial-based sensors for detection of foodborne bacterial pathogens and toxins as well as pork adulteration in meat products

    Directory of Open Access Journals (Sweden)

    B. Stephen Inbaraj

    2016-01-01

    Full Text Available Food safety draws considerable attention in the modern pace of the world owing to rapid-changing food recipes and food habits. Foodborne illnesses associated with pathogens, toxins, and other contaminants pose serious threat to human health. Besides, a large amount of money is spent on both analyses and control measures, which causes significant loss to the food industry. Conventional detection methods for bacterial pathogens and toxins are time consuming and laborious, requiring certain sophisticated instruments and trained personnel. In recent years, nanotechnology has emerged as a promising field for solving food safety issues in terms of detecting contaminants, enabling controlled release of preservatives to extend the shelf life of foods, and improving food-packaging strategies. Nanomaterials including metal oxide and metal nanoparticles, carbon nanotubes, and quantum dots are gaining a prominent role in the design of sensors and biosensors for food analysis. In this review, various nanomaterial-based sensors reported in the literature for detection of several foodborne bacterial pathogens and toxins are summarized highlighting their principles, advantages, and limitations in terms of simplicity, sensitivity, and multiplexing capability. In addition, the application through a noncross-linking method without the need for any surface modification is also presented for detection of pork adulteration in meat products.

  7. Microbial production of xylitol from xylose and L-arabinose: conversion of L-arabitol to xylitol using bacterial oxidoreductases

    Science.gov (United States)

    Microbial production of xylitol, using hemicellulosic biomass such as agricultural residues, is becoming more attractive for reducing its manufacturing cost. L-arabitol is a particular problem to xylitol production from hemicellulosic hydrolyzates that contain both xylose and L-arabinose because it...

  8. Effect Of GAMMA-Irradiation On Production And Characteristics Of Chitosan Produced From Crustacean Waste By Using Some Bacterial Strains

    International Nuclear Information System (INIS)

    INAS ISMAIL MAHMOUD RAAFAT

    2015-01-01

    The main study focused on separation of chitin from crustacean waste (shrimp shell) using some proteolytic bacterial isolates. After that, chitosan was obtained by deactylation and its characteristics were studied using some characterizing tools. The produced chitosan was degraded to different molecular weights and evaluated as an antibacterial agent. Seventy bacterial isolates were obtained from different sources (soil, plant roots and shrimp shell waste) and tested for their ability to produce proteolytic enzymes. One isolate was selected, due its high proteolytic activity and ability to grow using shrimp as carbon and nitrogen source on shrimp shell agar medium and identified as Bacillus subtilis NA12 by 16S-rRNA gene sequences with a high degree of similarity (99 %) as a gene bank database. Factors affecting deproteinization (DP) and demineralization (DM) efficiency of shrimp shell waste (SSW) (carbon source and its optimal concentration, shrimp shell waste concentration, inoculum size and fermentation time) were studied. The most efficient DP (92.40 %) and DM (81.37 %) of SSW by B. subtilis NA12 were sucrose 10 % (w/v) and inoculum size 15 % (v/v 35 x 108 CFU/ml ) to ferment shrimp shell waste 5 % (w/v) for 6 days of fermentation time. The effect of γ-irradiation on the performance of selected bacterial strain was studied to maximize chitin yield. Box-Behnken design using response surface methodology was employed to establish the relationship between the previous variables, implied that the model was highly significant. It was found that a sucrose concentration of 5 % (w/v), SSW of 12.5 % (w/v), inoculum size of 10 % (v/v) and fermentation time of 7 days; had a predicted value of DP of 97.65 % whereas the actual experiment gave 96.37 %. The predicted value of DM was 82.94 % whereas the actual experiment gave 82.19 %. Chitosan polymer was successfully prepared by the deacetylation reaction from fermented shrimp shell waste (SSW) by Bacillus subtilis NA12

  9. Accuracy of Digitally Fabricated Wax Denture Bases and Conventional Completed Complete Dentures

    Directory of Open Access Journals (Sweden)

    Bogna Stawarczyk

    2017-12-01

    Full Text Available The purpose of this investigation was to analyze the accuracy of digitally fabricated wax trial dentures and conventionally finalized complete dentures in comparison to a surface tessellation language (STL-dataset. A generated data set for the denture bases and the tooth sockets was used, converted into STL-format, and saved as reference. Five mandibular and 5 maxillary denture bases were milled from wax blanks and denture teeth were waxed into their tooth sockets. Each complete denture was checked on fit, waxed onto the dental cast, and digitized using an optical laboratory scanning device. The complete dentures were completed conventionally using the injection method, finished, and scanned. The resulting STL-datasets were exported into the three-dimensional (3D software GOM Inspect. Each of the 5 mandibular and 5 maxillary complete dentures was aligned with the STL- and the wax trial denture dataset. Alignment was performed based on a best-fit algorithm. A three-dimensional analysis of the spatial divergences in x-, y- and z-axes was performed by the 3D software and visualized in a color-coded illustration. The mean positive and negative deviations between the datasets were calculated automatically. In a direct comparison between maxillary wax trial dentures and complete dentures, complete dentures showed higher deviations from the STL-dataset than the wax trial dentures. The deviations occurred in the area of the teeth as well as in the distal area of the denture bases. In contrast, the highest deviations in both the mandibular wax trial dentures and the mandibular complete dentures were observed in the distal area. The complete dentures showed higher deviations on the occlusal surfaces of the teeth compared to the wax dentures. Computer-aided design/computer-aided manufacturing (CAD/CAM-fabricated wax dentures exhibited fewer deviations from the STL-reference than the complete dentures. The deviations were significantly greater in the

  10. POTENSI LILIN LEBAH HUTAN THE POTENTIAL BEES WAXS FROM WILD BEE

    Directory of Open Access Journals (Sweden)

    Muhammad Junus

    2017-11-01

    Full Text Available This research was carried out to examine the ability of forest resources in producing total (amount nest, hive comb lowering and beeswax of giant honey bee. The method used in this research was survey method. This research was conducted in July 2015 in Sialang Honey Community Cooperative (KOPMAS located in Sungai Pagar village, Riau province. The result indicated that a. The research location was suitable for giant honey bee (Apis dorsata development, b. The number of hive combs lowering from 15 trees was 411 combs with 67 times lowering, c. The average of hive comb weight in every lowering was around 40.6 kg. d. Beeswax production at every harvest time was 273.6 kg. The conclusions from this research were: 1. The number of giant honey bee hive combs from various trees and the weight of hive combs were not the same. 2. The amount of beeswax was equivalent to the production of bee hive comb. It is suggested that: 1. The utilization of giant honey bees wax should be designed so it can be used as a commodity to increase people’s incomes. 2. Certain policies are needed to develop giant honey bee activity around forest areas in order to produce more hive comb and beeswax.

  11. Isolation and recrystallization of epicuticular waxes from Sorbus and Cotoneaster leaves

    OpenAIRE

    Ganeva Tsveta; Stefanova Miroslava; Koleva Dimitrina; Ruiz Segundo Ríos

    2015-01-01

    Wax morphology and chemical composition are widely accepted to be important for the protective properties of the leaf’s surface and also valuable characteristics in plant systematics. The leaves of Sorbus domestica L. and Cotoneaster granatensis Boiss., species of two large genera with intricate taxonomy referred to subtribe Pyrinae, Rosaceae (formerly subfamily Maloideae), were studied by scanning electron microscope (SEM) and performing different methods of wax isola...

  12. ETHNOECOLOGY AND ETHNOBOTANY OF THE PALM CARNAUBA WAX IN BRAZILIAN SEMI-ARID

    OpenAIRE

    Rodrigo Ferreira de Sousa; Richeliel Albert Rodrigues Silva; Talita Geovanna Fernandes Rocha; José Augusto da Silva Santana; Fábio de Almeida Vieira

    2015-01-01

    The aim of this study was to investigate aspects of ethnoecological and ethnobotanical of carnauba wax (Copernicia prunifera (Miller) H. E. Moore, Arecaceae) in an extractive community of municipality of Ipanguaçu, Rio Grande do Norte state. We interviewed key informants, using the technique of inducing nonspecific, guided tour and direct observation to confirm the data. According to most residents of Pedro Ezequiel Araújo community, the area of carnauba wax in the region is natural. In the r...

  13. Epicuticular wax on stomata of damaged silver fir trees (Abies alba Mili.)

    OpenAIRE

    Tomislav Bačić; Ljiljana Krstin; Jadranka Roša; Željko Popović

    2011-01-01

    Condition of epistomatal wax on the abaxial surface of the current and previous-year needles of damaged silver fir trees (Abies alba Mill.), both from the polluted Risnjak and "clean" Donja Dobra sites in Gorski Kotar region, both influenced by pollutants coming from Europe, during two years, three times a year, were examined with Scanning Electron Microscope. In the course of time the wax tubules on the epistomatal rims of stomata in polluted, but also in "clean" needles surface, become fuse...

  14. A review of the performance and structural considerations of paraffin wax hybrid rocket fuels with additives

    Science.gov (United States)

    Veale, Kirsty; Adali, Sarp; Pitot, Jean; Brooks, Michael

    2017-12-01

    Paraffin wax as a hybrid rocket fuel has not been comprehensively characterised, especially regarding the structural feasibility of the material in launch applications. Preliminary structural testing has shown paraffin wax to be a brittle, low strength material, and at risk of failure under launch loading conditions. Structural enhancing additives have been identified, but their effect on motor performance has not always been considered, nor has any standard method of testing been identified between research institutes. A review of existing regression rate measurement techniques on paraffin wax based fuels and the results obtained with various additives are collated and discussed in this paper. The review includes 2D slab motors that enable visualisation of liquefying fuel droplet entrainment and the effect of an increased viscosity on the droplet entrainment mechanism, which can occur with the addition of structural enhancing polymers. An increased viscosity has been shown to reduce the regression rate of liquefying fuels. Viscosity increasing additives that have been tested include EVA and LDPE. Both these additives increase the structural properties of paraffin wax, where the elongation and UTS are improved. Other additives, such as metal hydrides, aluminium and boron generally offer improvements on the regression rate. However, very little consideration has been given to the structural effects these additives have on the wax grain. A 40% aluminised grain, for example, offers a slight increase in the UTS but reduces the elongation of paraffin wax. Geometrically accurate lab-scale motors have also been used to determine the regression rate properties of various additives in paraffin wax. A concise review of all available regression rate testing techniques and results