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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. How does forest productivity influence river export of plant wax?

    Science.gov (United States)

    Feakins, S. J.; West, A. J.; Galy, V.; Malhi, Y.; Girardin, C.; Asner, G. P.; Ponton, C.; Wu, M. S.

    2016-12-01

    How much carbon, fixed in tropical forest photosynthesis, is exported by rivers? From the large biomass held in tropical forests only a small component enters rivers for export. The exported fraction of tropical forest production represents the component removed from the rapid photosynthesis-respiration cycle, with potential for long-term sequestration in downstream sediments. Along the journey downstream, the transported organic matter may be lost to respiration, or stored in deposits before remobilization and later export. Discriminating between carbon sources in rivers presents a challenge to answering the question posed. But, plant waxes are specific tracers of plant biosynthesis that we use to identify sourcing and transport by the river, and that represent a resilient component with sequestration potential. Thus, we quantify the fraction of fresh forest production that goes into plant wax in a series of 9 forest plots in the Madre de Dios River catchment, Peru and set this in the context of catchment scale NPP estimates. Downstream sampling in two seasons captures the suspended particulate load of plant waxes in transit. Paired analyses of carbon and hydrogen isotopes allow for source apportionment by elevation allowing insight into catchment integration processes. Downstream concentrations of plant wax n-alkanes in river are related to discharge to yield estimates of the instantaneous catchment export flux in two contrasting seasons. Ultimately we seek to constrain the flux of plant wax exported by the river, and to estimate what fraction of forest NPP makes that journey from land to sea.

  3. 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

  4. Identification of chemical components of corn kernel pericarp wax associated with resistance to Aspergillus flavus infection and aflatoxin production.

    Science.gov (United States)

    Gembeh, S V; Brown, R L; Grimm, C; Cleveland, T E

    2001-10-01

    Kernel pericarp wax of the corn breeding population GT-MAS:gk has been associated with resistance to Aspergillus flavus infection and aflatoxin production. GT-MAS:gk wax, previously compared to waxes of three susceptible genotypes, was presently compared to wax of a different, and more numerous, group of susceptible lines. Wax separation by TLC confirmed previous findings, demonstrating a unique GT-MAS:gk band and a unique "susceptible" band. Only GT-MAS:gk wax inhibited the growth of A. flavus; however, no association was established, as before, between kernel wax abundance and resistance. Gas chromatography-mass spectroscopy (GC-MS) analysis of kernel whole wax showed a higher percentage of phenol-like compounds in wax from GT-MAS:gk than in waxes from the susceptible lines. The GT-MAS:gk unique band contained phenol-like compounds and ethyl-hexadecanoate; butyl-hexadecanoate was preeminent in most of the "susceptible bands". Alkylresorcinol (phenolic compounds) content was dramatically higher in GT-MAS:gk wax than in the wax of susceptible lines. An alkylresorcinol, 5-methylresorcinol, also inhibited in vitro growth of A. flavus. These and other phenolic compounds may contribute to kernel wax inhibition of A. flavus infection/aflatoxin production. Further investigation is needed to confirm a role for them in GT-MAS:gk resistance.

  5. Real-Time monitoring of intracellular wax ester metabolism

    Directory of Open Access Journals (Sweden)

    Karp Matti

    2011-09-01

    Full Text Available Abstract Background Wax esters are industrially relevant molecules exploited in several applications of oleochemistry and food industry. At the moment, the production processes mostly rely on chemical synthesis from rather expensive starting materials, and therefore solutions are sought from biotechnology. Bacterial wax esters are attractive alternatives, and especially the wax ester metabolism of Acinetobacter sp. has been extensively studied. However, the lack of suitable tools for rapid and simple monitoring of wax ester metabolism in vivo has partly restricted the screening and analyses of potential hosts and optimal conditions. Results Based on sensitive and specific detection of intracellular long-chain aldehydes, specific intermediates of wax ester synthesis, bacterial luciferase (LuxAB was exploited in studying the wax ester metabolism in Acinetobacter baylyi ADP1. Luminescence was detected in the cultivation of the strain producing wax esters, and the changes in signal levels could be linked to corresponding cell growth and wax ester synthesis phases. Conclusions The monitoring system showed correlation between wax ester synthesis pattern and luminescent signal. The system shows potential for real-time screening purposes and studies on bacterial wax esters, revealing new aspects to dynamics and role of wax ester metabolism in bacteria.

  6. 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.

  7. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    Energy Technology Data Exchange (ETDEWEB)

    Amitava Sarkar; James K. Neathery; Burtron H. Davis

    2006-12-31

    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 operation since the reaction is highly exothermic. Consequently, heavy wax products in one approach may 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 iron-based FTS and is a key factor for optimizing operating costs. The separation problem is further compounded by attrition of iron catalyst particles and the formation of ultra-fine particles.

  8. 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).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-09-30

    In this reporting period, a fundamental filtration study was continued to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. The overall focus of the program is with slurry-phase FTS in slurry bubble column reactor systems. Hydrocarbon products must be separated from catalyst particles before being removed from the reactor system. An efficient wax product/catalyst separation system is a key factor for optimizing operating costs for iron-based slurry-phase FTS. Previous work has focused on catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. With the current study, we are investigating how the filtration properties are affected by these chemical and physical changes of the catalyst slurry during activation/synthesis. The shakedown phase of the pilot-scale filtration platform was completed at the end of the last reporting period. A study of various molecular weight waxes was initiated to determine the effect of wax physical properties on the permeation rate without catalyst present. As expected, the permeation flux was inversely proportional to the nominal average molecular weight of the polyethylene wax. Even without catalyst particles present in the filtrate, the filtration membranes experience fouling during an induction period on the order of days on-line. Another long-term filtration test was initiated using a batch of iron catalyst that was previously activated with CO to form iron carbide in a separate continuous stirred tank reactor (CSTR) system. The permeation flux stabilized more rapidly than that experienced with unactivated catalyst tests.

  10. Bacterial contamination of blood products.

    Science.gov (United States)

    Palavecino, Elizabeth; Jacobs, Michael; Yomtovian, Roslyn

    2004-11-01

    The occurrence of a septic reaction resulting from bacterial contamination of blood products, particularly with room-temperature stored platelets, is the most common transfusion-associated infectious risk in the United States. Bacterial contamination of blood products was first identified more than 60 years ago; yet, strategies to resolve this problem have proved daunting despite ongoing awareness and increasing concern especially in the last few years. With the recent US Food and Drug Administration (FDA) approval of culture methods for quality control testing of platelet units and the promulgation of accreditation standards by the College of American Pathologists and American Association of Blood Banks to detect bacterially contaminated platelet units and to prevent transfusion of these units, blood banks and transfusion services have finally started to address this problem, in a more standardized manner. Furthermore, as new methods of interdicting, inactivating and detecting bacterially contaminated blood products emerge, it is hoped that the problem of bacterial contamination of blood products will be overcome.

  11. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-30

    In this reporting period, a study of ultra-fine iron catalyst filtration was initiated to study the behavior of ultra-fine particles during the separation of Fischer-Tropsch Synthesis (FTS) liquids filtration. The overall focus of the program is with slurry-phase FTS in slurry bubble column reactor systems. Hydrocarbon products must be separated from catalyst particles before being removed from the reactor system. An efficient wax product/catalyst separation system is a key factor for optimizing operating costs for iron-based slurry-phase FTS. Previous work has focused on catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. With the current study, we are investigating how the filtration properties are affected by these chemical and physical changes of the catalyst slurry during activation/synthesis. The change of particle size during the slurry-phase FTS has monitored by withdrawing catalyst sample at different TOS. The measurement of dimension of the HRTEM images of samples showed a tremendous growth of the particles. Carbon rims of thickness 3-6 nm around the particles were observed. This growth in particle size was not due to carbon deposition on the catalyst. A conceptual design and operating philosophy was developed for an integrated wax filtration system for a 4 liter slurry bubble column reactor to be used in Phase II of this research program. The system will utilize a primary inertial hydroclone followed by a Pall Accusep cross-flow membrane. Provisions for cleaned permeate back-pulsing will be included to as a flux maintenance measure.

  12. 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

  13. 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...

  14. Production variables affecting characteristics of pellets in melt pelletization with wax combination in a laboratory scale spheronizer.

    Science.gov (United States)

    Biswal, Sudarsan; Sahoo, Jagannath; Murthy, Padala Narasimham; Giradkar, Rajesh Pandurang; Das, Subash; Avari, Jasmine Gev

    2009-06-01

    The purpose of the study was to evaluate the suitability of laboratory scale spheronizer for the production of spherical pellets loaded with diltiazem hydrochloride by wax combination. The 1:1 combination of cetyl alcohol and hydrogenated castor oil, as low and high melting point waxes, were used. The various production variables affecting the different characteristics of pellets and the process efficiency were evaluated. Drug loaded pellets were evaluated for drug release in distilled water. Bowl temperature primarily affects the sphericity and adhesion of pellets to the bowl. Mass temperature has a pronounced effect on size, size distribution and sphericity of pellets. Wax concentration affects all characteristics of pellets but adhesion was least affected. The effect of these three variables can be compensated by optimizing the friction plate speed. It has been found that the highest yield of pellets (850--1400 microm) with maximum sphericity can be produced by using 45 degrees C bowl temperature, 52 degrees C mass temperature and 1400 rpm friction plate speed.

  15. 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

  16. 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.

  17. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-31

    The morphological and chemical nature of ultrafine iron catalyst particles (3-5 nm diameters) during activation/FTS was studied by HRTEM, EELS, and Moessbauer spectroscopy. With the progress of FTS, the carbide re-oxidized to magnetite and catalyst activity gradually decreased. The growth of oxide phase continued and average particle size also increased simultaneously. The phase transformation occurred in a ''growing oxide core'' manner with different nano-zones. The nano-range carbide particles did not show fragmentation or attrition as generally observed in micrometer range particles. Nevertheless, when the dimension of particles reached the micrometer range, the crystalline carbide phase appeared to be sprouted on the surface of magnetite single crystal. In the previous reporting period, a design and operating philosophy was developed for an integrated wax filtration system for a 4 liter slurry bubble column reactor to be used in Phase II of this research program. During the current reporting period, we have started construction of the new filtration system and began modifications to the 4 liter slurry bubble column reactor (SBCR) reactor. The system will utilize a primary wax separation device followed by a Pall Accusep or Membralox ceramic cross-flow membrane. As of this writing, the unit is nearly complete except for the modification of a moyno-type pump; the pump was shipped to the manufacturer to install a special leak-free, high pressure seal.

  18. Production of Oleic Acid Based Wax Ester Using Acidic Homogeneous Catalysts

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    Naowara Al-Arafi

    2012-01-01

    Full Text Available Four homogeneous acidic catalysts were tested for their ability to catalyze the esterification reaction of oleic acid and oleyl alcohol to produce oleyl oleate, a wax ester. Sulfuric acid showed relatively higher specific activity. Various reaction parameters were optimised to obtain high percentage yield of oleyl oleate. The optimum condition to produce oeyl oleate was reaction time; 5 h, temperture; 90°C, amount of sulforic acid 0.15 g and molar ratio of oleyl alcohol to oleic acid; 1:1. Percentage yield of wax ester obtained at these optimum reaction conditions was 93.88. Disappearance of carboxylic acid (C=O peak has confirmed by FTIR with appearance of ester (C=O peak at 1739 cm−1. 1H NMR spectra analyses confirmed the result of oleyl oleate with appearance of ester (-CH2OCOR at 4.02 ppm and also the 13C-NMR confirmed the result with appearance of ester (C=O peak at 173.2 ppm. The low-temperture behavior of compound synthesized was determined through its pour point (PP, viscosity index (VI and flash point (FP values. The results showed that oleyl oleate exhibited the most favorable low-temperture performance of PP, VI and FP with −31°C, 197.5 and 320°C respectively. This is due to increase of the molacular weight thus improve the low temperture property significantly.

  19. 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.

  20. 21 CFR 178.3720 - Petroleum wax, synthetic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Petroleum wax, synthetic. 178.3720 Section 178.3720... Certain Adjuvants and Production Aids § 178.3720 Petroleum wax, synthetic. Synthetic petroleum wax may be safely used in applications and under the same conditions where naturally derived petroleum wax is...

  1. Production and characterization of vaginal suppositories with propolis wax as active agent to prevent and treat Fluor albus

    Science.gov (United States)

    Farida, Siti; Azizah, Nurul; Hermansyah, Heri; Sahlan, Muhamad

    2017-02-01

    Based on the content contained in propolis wax especially antimicrobial function, it can be analyzed that propolis wax had superiority for Fluor albus. This research was conducted on two formulation of vaginal suppositories with base, supplementary and active agent as a fixed variable: 2% propolis wax (% w/w). Evaluation of this research were weight variation, melting time, consistency, irritation effect test and physical and chemical stability test (organoleptic, pH and polyphenol content).

  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

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    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 systems for production of heterologous proteins.

    Science.gov (United States)

    Zerbs, Sarah; Frank, Ashley M; Collart, Frank R

    2009-01-01

    Proteins are the working molecules of all biological systems and participate in a majority of cellular chemical reactions and biological processes. Knowledge of the properties and function of these molecules is central to an understanding of chemical and biological processes. In this context, purified proteins are a starting point for biophysical and biochemical characterization methods that can assist in the elucidation of function. The challenge for production of proteins at the scale and quality required for experimental, therapeutic and commercial applications has led to the development of a diverse set of methods for heterologous protein production. Bacterial expression systems are commonly used for protein production as these systems provide an economical route for protein production and require minimal technical expertise to establish a laboratory protein production system.

  6. Computational study of wax deposition in pipeline

    Science.gov (United States)

    Duan, Jimiao; Gong, Jing; Liu, Huishu

    2013-07-01

    Wax deposition in subsea pipelines is one of the flow assurance problems for oil and gas production. In contrast to many studies about single phase wax deposition, gas-oil wax deposition studies are very limited. The wax deposition mechanism and model prediction are restricted by many factors such as hydrodynamic and thermal when multiphase flow is involved. Wax deposition modeling becomes complicated under multiphase flowing conditions. wax deposition is depended by the flow pattern. The stratified flow is one of the most common flow patterns in the actual subsea gas-oil flowing conditions. In this work, numerical methods are used to study wax deposition in oil-gas stratified flow through a pipe. Based on the flow analysis about stratified flow, the non-isothermal heat and mass transfer is calculated. The temperature profile of the oil and the concentration profile of wax in oil are obtained. The change of the oil-gas interface i.e. the liquid holdup throughout the pipe must be taken into the heat and mass balance. The valid wax deposition surface must be taken into the wax deposition modeling by establishing function of the liquid holdup and the wetted area by oil. The molecular diffusion is as the deposition mechanism. The increase of the wax fraction in the deposit as a function of time depends on the mass flux from the oil deposit interface into the gel and the growth of the deposit thickness depends on the difference between the mass flux from the bulk oil to the oil deposit interface and the mass flux from the interface into the deposit. In addition, the growth of the wax deposit as a function of time along with the effect oil flow rate, gas flow rate and the inlet temperature are discussed. The presence of gas significantly reduces the severity of wax deposition by altering the heat and mass transfer characteristics.

  7. Morphology and networks of sunflower wax crystals in organogel

    Science.gov (United States)

    Plant waxes are considered as promising alternatives to unhealthy solid fats such as trans fats and saturated fats in structured food products including margarines and spreads. Sunflower wax is of a great interest due to its strong gelling ability. Morphology of sunflower wax crystals formed in soyb...

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

    DEFF Research Database (Denmark)

    Lehtinen, Tapio; Efimova, Elena; Tremblay, Pier-Luc

    2017-01-01

    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......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...

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. Enhancement of photosynthetic capacity in Euglena gracilis by expression of cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase leads to increases in biomass and wax ester production.

    Science.gov (United States)

    Ogawa, Takahisa; Tamoi, Masahiro; Kimura, Ayako; Mine, Ayaka; Sakuyama, Harumi; Yoshida, Eriko; Maruta, Takanori; Suzuki, Kengo; Ishikawa, Takahiro; Shigeoka, Shigeru

    2015-01-01

    Microalgae have recently been attracting attention as a potential platform for the production of biofuels. Euglena gracilis, a unicellular phytoflagellate, has been proposed as an attractive feedstock to produce biodiesel because it can produce large amounts of wax esters, consisting of medium-chain fatty acids and alcohols with 14:0 carbon chains. E. gracilis cells highly accumulate a storage polysaccharide, a β-1,3-glucan known as paramylon, under aerobic conditions. When grown aerobically and then transferred into anaerobic conditions, E. gracilis cells degrade paramylon to actively synthesize and accumulate wax esters. Thus, the enhanced accumulation of paramylon through the genetic engineering of photosynthesis should increase the capacity for wax ester production. We herein generated transgenic Euglena (EpFS) cells expressing the cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase (FBP/SBPase), which is involved in the Calvin cycle, to enhance its photosynthetic activity. FBP/SBPase was successfully expressed within Euglena chloroplasts. The cell volume of the EpFS4 cell line was significantly larger than that of wild-type cells under normal growth conditions. The photosynthetic activity of EpFS4 cells was significantly higher than that of wild type under high light and high CO2, resulting in enhanced biomass production, and the accumulation of paramylon was increased in transgenic cell lines than in wild-type cells. Furthermore, when EpFS cell lines grown under high light and high CO2 were placed on anaerobiosis, the productivity of wax esters was approximately 13- to 100-fold higher in EpFS cell lines than in wild-type cells. Our results obtained here indicate that the efficiency of biomass production in E. gracilis can be improved by genetically modulating photosynthetic capacity, resulting in the enhanced production of wax esters. This is the first step toward the utilization of E. gracilis as a sustainable source for biofuel production under

  14. Bacterial polyhydroxybutyrate for electrospun fiber production.

    Science.gov (United States)

    Acevedo, Francisca; Villegas, Pamela; Urtuvia, Viviana; Hermosilla, Jeyson; Navia, Rodrigo; Seeger, Michael

    2018-01-01

    Nano- and microfibers obtained by electrospinning have attracted great attention due to its versatility and potential for applications in diverse technological fields. Polyhydroxyalkanoates (PHAs) are biopolymers synthesized by microorganisms such as the bacterium Burkholderia xenovorans LB400. In particular, LB400 cells are capable to synthesize poly(3-hydroxybutyrate) (PHB) from glucose. The aim of this study was to produce and characterize electrospun fibers obtained from bacterial PHBs. Bacterial strain LB400 was grown in M9 minimal medium using xylose and mannitol (10gL -1 ) as the sole carbon sources and NH 4 Cl (1gL -1 ) as the sole nitrogen source. Biopolymer-based films obtained were used to produce fibers by electrospinning. Diameter and morphology of the microfibers were analyzed by scanning electron microscopy (SEM) and their thermogravimetric properties were investigated. Bead-free fibers using both PHBs were obtained with diameters of less than 3μm. The surface morphology of the microfibers based on PHBs obtained from both carbon sources was different, even though their thermogravimetric properties are similar. The results indicate that the carbon source may determine the fiber structure and properties. Further studies should be performed to analyze the physicochemical and mechanical properties of these PHB-based microfibers, which may open up novel applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. 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

  16. 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

  17. 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.

  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. 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

  20. Production of Polyhydroxyalkanoates, a bacterial biodegradable ...

    African Journals Online (AJOL)

    Administrator

    There has been considerable interest in the development and production of biodegradable polymer to solve the current problem of pollution caused ... horticultural agricultural waste, corn, cassava etc would be of economic interest considering the .... for efficient production of PHAs. (Yu, 2001, Du et al.,. 2001b; Du and Yu, ...

  1. Production of Polyhydroxyalkanoates, a bacterial biodegradable ...

    African Journals Online (AJOL)

    ... production has restricted its applications. The possibility of producing this polymer commercially and at comparable cost has been the main focus in this area. Key Words: Polyhydroxyalkanoates, biodegradable polymer, bioplastic, poly(3-hydroxybutyrate), biosynthesis. African Journal of Biotechnology Vol.3(1) 2004: 18- ...

  2. 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.

  3. 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.

  4. Space-based bacterial production of hydrogen

    Science.gov (United States)

    Tennakoon, C. L.; Bhardwaj, R. C.; Bockris, J. O.; Henninger, D. L. (Principal Investigator)

    1994-01-01

    This paper deals with the electrochemical production of hydrogen by depolarizing the oxygen evolution reaction using human feces and urine, which contains 30-40% bacteria and yeast. The electroactivity of graphite, tungsten carbide, perovskite and RuO2-coated Ebonex (Ti4O7) as anode materials are compared. The scale-up of the process in a laboratory-scale three-dimensional packed bed cell is discussed.

  5. Effects of wax treatment on quality and postharvest physiology of ...

    African Journals Online (AJOL)

    Fresh 7055 wax) of pineapple fruits of cultivar'Paris' (a major cultivar for pineapple production) on alleviating chilling injury and their physiological responses during cold storage were examined. Sta-Fresh 2952 wax (60 g/l) was more effective in: ...

  6. 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.

  7. 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.

  8. 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.

  9. Enhancement of photosynthetic capacity in Euglena gracilis by expression of cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase leads to increases in biomass and wax ester production

    OpenAIRE

    Ogawa, Takahisa; Tamoi, Masahiro; Kimura, Ayako; Mine, Ayaka; Sakuyama, Harumi; Yoshida, Eriko; Maruta, Takanori; Suzuki, Kengo; Ishikawa, Takahiro; Shigeoka, Shigeru

    2015-01-01

    Background Microalgae have recently been attracting attention as a potential platform for the production of biofuels. Euglena gracilis, a unicellular phytoflagellate, has been proposed as an attractive feedstock to produce biodiesel because it can produce large amounts of wax esters, consisting of medium-chain fatty acids and alcohols with 14:0 carbon chains. E. gracilis cells highly accumulate a storage polysaccharide, a ?-1,3-glucan known as paramylon, under aerobic conditions. When grown a...

  10. 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.

  11. 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.

  12. Detailed characterization of the substrate specificity of mouse wax synthase.

    Science.gov (United States)

    Miklaszewska, Magdalena; Kawiński, Adam; Banaś, Antoni

    2013-01-01

    Wax synthases are membrane-associated enzymes catalysing the esterification reaction between fatty acyl-CoA and a long chain fatty alcohol. In living organisms, wax esters function as storage materials or provide protection against harmful environmental influences. In industry, they are used as ingredients for the production of lubricants, pharmaceuticals, and cosmetics. Currently the biological sources of wax esters are limited to jojoba oil. In order to establish a large-scale production of desired wax esters in transgenic high-yielding oilseed plants, enzymes involved in wax esters synthesis from different biological resources should be characterized in detail taking into consideration their substrate specificity. Therefore, this study aims at determining the substrate specificity of one of such enzymes -- the mouse wax synthase. The gene encoding this enzyme was expressed heterologously in Saccharomyces cerevisiae. In the in vitro assays (using microsomal fraction from transgenic yeast), we evaluated the preferences of mouse wax synthase towards a set of combinations of 11 acyl-CoAs with 17 fatty alcohols. The highest activity was observed for 14:0-CoA, 12:0-CoA, and 16:0-CoA in combination with medium chain alcohols (up to 5.2, 3.4, and 3.3 nmol wax esters/min/mg microsomal protein, respectively). Unsaturated alcohols longer than 18°C were better utilized by the enzyme in comparison to the saturated ones. Combinations of all tested alcohols with 20:0-CoA, 22:1-CoA, or Ric-CoA were poorly utilized by the enzyme, and conjugated acyl-CoAs were not utilized at all. Apart from the wax synthase activity, mouse wax synthase also exhibited a very low acyl-CoA:diacylglycerol acyltransferase activity. However, it displayed neither acyl-CoA:monoacylglycerol acyltransferase, nor acyl-CoA:sterol acyltransferase activity.

  13. Production and Status of Bacterial Cellulose in Biomedical Engineering

    Science.gov (United States)

    Moniri, Mona; Boroumand Moghaddam, Amin; Abdul Rahim, Raha; Bin Ariff, Arbakariya; Zuhainis Saad, Wan; Navaderi, Mohammad; Mohamad, Rosfarizan

    2017-01-01

    Bacterial cellulose (BC) is a highly pure and crystalline material generated by aerobic bacteria, which has received significant interest due to its unique physiochemical characteristics in comparison with plant cellulose. BC, alone or in combination with different components (e.g., biopolymers and nanoparticles), can be used for a wide range of applications, such as medical products, electrical instruments, and food ingredients. In recent years, biomedical devices have gained important attention due to the increase in medical engineering products for wound care, regeneration of organs, diagnosis of diseases, and drug transportation. Bacterial cellulose has potential applications across several medical sectors and permits the development of innovative materials. This paper reviews the progress of related research, including overall information about bacterial cellulose, production by microorganisms, mechanisms as well as BC cultivation and its nanocomposites. The latest use of BC in the biomedical field is thoroughly discussed with its applications in both a pure and composite form. This paper concludes the further investigations of BC in the future that are required to make it marketable in vital biomaterials.

  14. Wax Reinforces Honeycomb During Machining

    Science.gov (United States)

    Towell, Timothy W.; Fahringer, David T.; Vasquez, Peter; Scheidegger, Alan P.

    1995-01-01

    Method of machining on conventional metal lathe devised for precise cutting of axisymmetric contours on honeycomb cores made of composite (matrix/fiber) materials. Wax filling reinforces honeycomb walls against bending and tearing while honeycomb being contoured on lathe. Innovative method of machining on lathe involves preparation in which honeycomb is placed in appropriate fixture and the fixture is then filled with molten water-soluble wax. Number of different commercial waxes have been tried.

  15. 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.

  16. The Bacterial Ghost platform system: production and applications.

    Science.gov (United States)

    Langemann, Timo; Koller, Verena Juliana; Muhammad, Abbas; Kudela, Pavol; Mayr, Ulrike Beate; Lubitz, Werner

    2010-01-01

    The Bacterial Ghost (BG) platform technology is an innovative system for vaccine, drug or active substance delivery and for technical applications in white biotechnology. BGs are cell envelopes derived from Gram-negative bacteria. BGs are devoid of all cytoplasmic content but have a preserved cellular morphology including all cell surface structures. Using BGs as delivery vehicles for subunit or DNA-vaccines the particle structure and surface properties of BGs are targeting the carrier itself to primary antigen-presenting cells. Furthermore, BGs exhibit intrinsic adjuvant properties and trigger an enhanced humoral and cellular immune response to the target antigen. Multiple antigens of the native BG envelope and recombinant protein or DNA antigens can be combined in a single type of BG. Antigens can be presented on the inner or outer membrane of the BG as well as in the periplasm that is sealed during BG formation. Drugs or supplements can also be loaded to the internal lumen or periplasmic space of the carrier. BGs are produced by batch fermentation with subsequent product recovery and purification via tangential flow filtration. For safety reasons all residual bacterial DNA is inactivated during the BG production process by the use of staphylococcal nuclease A and/or the treatment with β-propiolactone. After purification BGs can be stored long-term at ambient room temperature as lyophilized product. The production cycle from the inoculation of the pre-culture to the purified BG concentrate ready for lyophilization does not take longer than a day and thus meets modern criteria of rapid vaccine production rather than keeping large stocks of vaccines. The broad spectrum of possible applications in combination with the comparably low production costs make the BG platform technology a safe and sophisticated product for the targeted delivery of vaccines and active agents as well as carrier of immobilized enzymes for applications in white biotechnology. © 2010 Landes

  17. 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

  18. X-rays control bacterial contamination in food products

    International Nuclear Information System (INIS)

    Zani, M.L.

    2000-01-01

    In order to control the lack of bacterial contamination of liquid food products, 'Nestle clinical nutrition' firm uses a new system based on the X-ray image of the content of sealed tins when these tins undergo a quick move on the conveyor belt. This moves induces a wave of product inside the tin and the amplitude of that wave is directly linked to the viscosity of the product which is linked to the presence or not of bacteria. The X-ray image is processed and the wave is characterized by 5 parameters. Any tin for which one at least of the 5 parameters does not match the calibration values is discarded. This system can process 10 tins per second. (A.C.)

  19. 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.

  20. 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.

    Seasonal and spatial variations in bacterial and picoplankton abundances and bacterial production (thymidine incorporation rates) were determined in the water column up to 150 m in several stations in the central and eastern Arabian Sea. Higher...

  1. 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).

  2. 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 C.; Hu, Dehong; Lemke, Rachelle A.; Piotrowski, Jeff S.; Orr, Galya; Noguera, Daniel R.; Donohue, Timothy J.; Ruby, Edward G.

    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

  3. WAXS investigation of lanthanide borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Bouty, O. [DEN/DTEC/SEPE, CEA Marcoule, BP 17171, Bagnols-sur-Ceze cedex, 30207 (France); Delaye, J.M.; DeBonfils, J.; Peuget, S. [DEN/DTCD/SECM, CEA Marcoule, BP 17171, Bagnols-sur-Ceze cedex, 30207 (France)

    2008-07-01

    Structural characterization of nuclear glasses requires the combination of several experimental and simulation techniques. Experimental ones probe the electronic environment at short distances (EXAFS, NMR) or at medium range distances (WAXS, AWAXS) or the nuclear environment (neutron scattering). We have built a new competence in X Ray Wide Angle Scattering (WAXS) by mounting two based-lab diffractometers with Mo X ray tubes, one of them being located in a shielded glove box, and by writing a new software to easily extract structure factors and radial distribution functions from the experiment. We present here a preliminary study of a simplified borosilicate glass doped with Eu (europium), which is a fission product, and which is often used as a stimulant of trivalent actinides. The WAXS technique has been successfully applied, the structure factor being in good agreement with the one obtained by molecular dynamics simulation. Thus, knowledge of the Eu local environment has been deduced and results compared with data from EXAFS and NMR analysis. (authors)

  4. 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

  5. Waxes in asphaltenes of crude oils and wax deposits

    Directory of Open Access Journals (Sweden)

    Yulia M. Ganeeva

    2016-07-01

    Full Text Available Abstract Composition and molecular mass distribution of n-alkanes in asphaltenes of crude oils of different ages and in wax deposits formed in the borehole equipment were studied. In asphaltenes, n-alkanes from C12 to C60 were detected. The high molecular weight paraffins in asphaltenes would form a crystalline phase with a melting point of 80–90 °C. The peculiarities of the redistribution of high molecular paraffin hydrocarbons between oil and the corresponding wax deposit were detected. In the oils, the high molecular weight paraffinic hydrocarbons C50–C60 were found, which were not practically detected in the corresponding wax deposits.

  6. Wax esters of different compositions produced via engineering of leaf chloroplast metabolism in Nicotiana benthamiana.

    Science.gov (United States)

    Aslan, Selcuk; Sun, Chuanxin; Leonova, Svetlana; Dutta, Paresh; Dörmann, Peter; Domergue, Frédéric; Stymne, Sten; Hofvander, Per

    2014-09-01

    In a future bio-based economy, renewable sources for lipid compounds at attractive cost are needed for applications where today petrochemical derivatives are dominating. Wax esters and fatty alcohols provide diverse industrial uses, such as in lubricant and surfactant production. In this study, chloroplast metabolism was engineered to divert intermediates from de novo fatty acid biosynthesis to wax ester synthesis. To accomplish this, chloroplast targeted fatty acyl reductases (FAR) and wax ester synthases (WS) were transiently expressed in Nicotiana benthamiana leaves. Wax esters of different qualities and quantities were produced providing insights to the properties and interaction of the individual enzymes used. In particular, a phytyl ester synthase was found to be a premium candidate for medium chain wax ester synthesis. Catalytic activities of FAR and WS were also expressed as a fusion protein and determined functionally equivalent to the expression of individual enzymes for wax ester synthesis in chloroplasts. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Bacterial diversity in relation to secondary production and succession on surfaces of the kelp Laminaria hyperborea

    Science.gov (United States)

    Bengtsson, Mia M; Sjøtun, Kjersti; Lanzén, Anders; Øvreås, Lise

    2012-01-01

    Kelp forests worldwide are known as hotspots for macroscopic biodiversity and primary production, yet very little is known about the biodiversity and roles of microorganisms in these ecosystems. Secondary production by heterotrophic bacteria associated to kelp is important in the food web as a link between kelp primary production and kelp forest consumers. The aim of this study was to investigate the relationship between bacterial diversity and two important processes in this ecosystem; bacterial secondary production and primary succession on kelp surfaces. To address this, kelp, Laminaria hyperborea, from southwestern Norway was sampled at different geographical locations and during an annual cycle. Pyrosequencing (454-sequencing) of amplicons of the 16S rRNA gene of bacteria was used to study bacterial diversity. Incorporation of tritiated thymidine was used as a measure of bacterial production. Our data show that bacterial diversity (richness and evenness) increases with the age of the kelp surface, which corresponds to the primary succession of its bacterial communities. Higher evenness of bacterial operational taxonomical units (OTUs) is linked to higher bacterial production. Owing to the dominance of a few abundant OTUs, kelp surface biofilm communities may be characterized as low-diversity habitats. This is the first detailed study of kelp-associated bacterial communities using high-throughput sequencing and it extends current knowledge on microbial community assembly and dynamics on living surfaces. PMID:22763650

  8. 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.

  9. Method for construction of bacterial strains with increased succinic acid production

    Science.gov (United States)

    Donnelly, Mark I.; Sanville-Millard, Cynthia; Chatterjee, Ranjini

    2000-01-01

    A fermentation process for producing succinic acid is provided comprising selecting a bacterial strain that does not produce succinic acid in high yield, disrupting the normal regulation of sugar metabolism of said bacterial strain, and combining the mutant bacterial strain and selected sugar in anaerobic conditions to facilitate production of succinic acid. Also provided is a method for changing low yield succinic acid producing bacteria to high yield succinic acid producing bacteria comprising selecting a bacterial strain having a phosphotransferase system and altering the phosphotransferase system so as to allow the bacterial strain to simultaneously metabolize different sugars.

  10. Lost-Wax Casting in Ancient China: New Discussion on Old Debates

    Science.gov (United States)

    Zhou, Weirong; Huang, Wei

    2015-07-01

    The possible use of lost-wax casting in China has long been a matter of controversy. Based on the study of pertinent ancient texts concerning the technical origins of lost-wax casting in China, direct examination of questioned ancient Chinese bronzes as well as definite lost-wax castings from both overseas and China, and modern production of objects using piece-mold casting, the authors point out their own conceptual ideas about ancient lost-wax casting as follows. First, the lost-wax casting technique does not have its earliest origins in ancient China but rather from the Sumerians in Mesopotamia, where it was predominantly used to cast small human and animal figures (statuettes). Next, some essential characteristics of the lost-wax casting technique can be identified from the point of view of a distortable soft starting model. The locally deformed shape of lost-wax castings is found to be variable. Finally, it is improper to consider the ease of extraction from the mold as the criterion for distinguishing lost-wax casting from piece-mold casting. It is therefore incorrect to conclude that the three-dimensional openwork decorations present on Chinese bronzes from the Spring and Autumn Period, and the Warring States Period, are fabricated using lost-wax castings.

  11. Critical Involvement of Environmental Carbon Dioxide Fixation to Drive Wax Ester Fermentation in Euglena

    Science.gov (United States)

    Nishio, Kazuki; Nakazawa, Masami; Nakamoto, Masatoshi; Okazawa, Atsushi; Kanaya, Shigehiko; Arita, Masanori

    2016-01-01

    Accumulation profiles of wax esters in Euglena gracilis Z were studied under several environmental conditions. The highest amount of total wax esters accumulated under hypoxia in the dark, and C28 (myristyl-myristate, C14:0-C14:0) was prevalent among all conditions investigated. The wax ester production was almost completely suppressed under anoxia in the light, and supplying exogenous inorganic carbon sources restored wax ester fermentation, indicating the need for external carbon sources for the wax ester fermentation. 13C-labeling experiments revealed specific isotopic enrichment in the odd-numbered fatty acids derived from wax esters, indicating that the exogenously-supplied CO2 was incorporated into wax esters via the propionyl-CoA pathway through the reverse tricarboxylic acid (TCA) cycle. The addition of 3-mercaptopicolinic acid, a phosphoenolpyruvate carboxykinase (PEPCK) inhibitor, significantly affected the incorporation of 13C into citrate and malate as the biosynthetic intermediates of the odd-numbered fatty acids, suggesting the involvement of PEPCK reaction to drive wax ester fermentation. Additionally, the 13C-enrichment pattern of succinate suggested that the CO2 assimilation might proceed through alternative pathways in addition to the PEPCK reaction. The current results indicate that the mechanisms of anoxic CO2 assimilation are an important target to reinforce wax ester fermentation in Euglena. PMID:27669566

  12. Bioinspired Composite Coating with Extreme Underwater Superoleophobicity and Good Stability for Wax Prevention in the Petroleum Industry.

    Science.gov (United States)

    Liang, Weitao; Zhu, Liqun; Li, Weiping; Yang, Xin; Xu, Chang; Liu, Huicong

    2015-10-13

    Wax deposition is a detrimental problem that happens during crude oil production and transportation, which greatly reduces transport efficiency and causes huge economic losses. To avoid wax deposition, a bioinspired composite coating with excellent wax prevention and anticorrosion properties is developed in this study. The prepared coating is composed of three films, including an electrodeposited Zn film for improving corrosion resistance, a phosphating film for constructing fish-scale morphology, and a silicon dioxide film modified by a simple spin-coating method for endowing the surface with superhydrophilicity. Good wax prevention performance has been investigated in a wax deposition test. The surface morphology, composition, wetting behaviors, and stability are systematically studied, and a wax prevention mechanism is proposed, which can be calculated from water film theory. This composite coating strategy which shows excellent properties in both wax prevention and stability is expected to be widely applied in the petroleum industry.

  13. 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

  14. Correlation of adjuvant activity and chemical structure of wax D fractions of mycobacteria*

    Science.gov (United States)

    White, R. G.; Jollès, P.; Samour, D.; Lederer, E.

    1964-01-01

    By fractionation of wax D from mycobacteria by ultracentrifugation in ether, it is possible to prepare from wax D of human strains peptide-containing and non-peptide-containing compounds. The peptide-containing fractions, like the parent wax D, were able to act as adjuvants by increasing serum anti-ovalbumin levels, by increasing corneal hypersensitivity to ovalbumin, and by inducing encephalomyelitis after homologous guinea-pig brain injection. The peptide—carbohydrate moiety resulting from hydrolysis of the whole wax D was found inactive in all these biological effects. When the same centrifugal technique was applied to several bovine types of Mycobacterium tuberculosis, M. avium and to atypical and saprophytic mycobacteria, analogous peptide and non-peptide-containing fractions were obtained. The amino acid patterns of these were of great variety, and in most cases differed from those present in human type wax D. In three instances a small proportion of a peptide-containing fraction was obtained (from M. phlei, M. avium and an atypical mycobacterium), which closely resembled a human type wax D. These fractions were found to have adjuvant activity. All other fractions of wax D of bovine, avian and saprophytic strains were inactive. These facts support the role of a peptide of D- and L-alanine, D-glutamic acid and meso-α,α'-diaminopimelic acid in determining the adjuvant action of wax D fractions and whole mycobacteria. The structure of the peptidoglycolipid of an adjuvant-active mycobacterial wax corresponds closely in amino acid, amino sugar and hexose composition with the mucopeptide of the bacterial cell wall, and evidence is discussed for the concept of wax D fractions as partial replicas of a fundamental cell wall polymer. PMID:14135432

  15. 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.

  16. 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.

  17. Heterotrophic bacterial production: Relationships to biological and abiological factors in estuarine environments

    International Nuclear Information System (INIS)

    Koepfler, E.T.

    1989-01-01

    Ecotoxicological effects of creosote contamination on benthic bacterial communities in the Elizabeth River, Virginia were investigated using both structural an functional microbial parameters. Results indicated that cell specific and total heterotrophic bacterial production parameters were depressed in a dose-dependent manner with increasing sediment PAH concentrations. Toxicity effects upon production were modified by temporal trends associated with temperature as well as spatial sediment characteristics. Of the parameters employed, the tritiated thymidine production assay was found to be the most sensitive for detection of ecotoxicological effects. Bacterial abundance and production were examined during a destratification event in the lower James River, Virginia. Bacterial abundance, although significantly different between stations, did not change over the study. Bacterial production ( 3 H-Tdr incorporation) in surface waters was significantly less during the mixed period 187 μg C·1-1· d -1 compared to the most stratified state (324μg C·1-1· d -1 ). Correlations between bacteria and chlorophyll were diminished during the mixed period. Total and flagellate specific grazing rates upon bacteria were reduced during the onset of destratification. Relationships between bacterial and nutrient parameters also indicated a strong influence of destratification. These results indicate that destratification changes trophic interactions within the microbial loop, which are not necessarily reflected in temporal patterns of bacterial abundance. Bacterioplankton production, and ammonium assimilation and remineralization were examined between April and August 1988 in the lower York River, Va

  18. Bacterial diversity in dried colostrum and whey sold as nutraceutical products.

    Science.gov (United States)

    Hayes, M Melissa; Hughes, Thomas A; Greene, Annel K

    2012-07-01

    The microbial communities were analyzed from commercially available dried dairy nutraceutical products, including 4 brands of dried colostrum, 2 brands of dried whey, and 1 brand of nonfat dry milk. A culture-dependent 16S rRNA sequencing approach was utilized to elucidate the identity of individual isolates recovered from each dried dairy product. Approximately 69% of all bacterial isolates were members the genus of Bacillus, while approximately 14% of all bacterial isolates were identified as members of the genus Pseudomonas. Members of the Kocuria, Microbacterium, and Enterococcus genera were identified as well. This project investigated the microbial populations inherent in dried commercially available nutraceutical products. Bovine colostrum has been reported to have protective activity against certain viral and bacterial pathogens. This project was designed to identify the bacterial populations within dried dairy nutraceutical products to determine if any species were common to all products and which may impact the reported nutraceutical properties. © 2012 Institute of Food Technologists®

  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. Comparison of transgenic plant production for bacterial blight ...

    African Journals Online (AJOL)

    The study was carried out to improve bacterial leaf blight resistance in three rice cultivars (Basmati - 370, DR - 82 and IR - 6) by Agrobacterium mediated transformation system. Three week-old scutellum derived calli were infected with Agrobacterium strain EHA101, containing binary vector pTCL5 which has Xa 21 gene.

  1. 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 ...

  2. Production and characterization of heavy-metal removing bacterial ...

    African Journals Online (AJOL)

    DINESH

    2012-05-17

    May 17, 2012 ... capacity of bioflocculant could be further stimulated by an increase in temperature. The pH requirement for maximum ... have previously demonstrated the ability of bacterial bioflocculants simultaneously in ..... molecules and weaken the static repulsive force, and promote floc formation (Li et al., 2008; He et ...

  3. Comparison of transgenic plant production for bacterial blight ...

    African Journals Online (AJOL)

    USER

    2010-03-29

    Mar 29, 2010 ... and observed a positive effect on control of bacterial contamination in indica rice as well enhancement in calli growth. Khan et al. (2007) used 500 mg/l cefotoxime in combination with 500 mg/l carbencillin in Basmati - 370 for selection; however, Arencibia et al. (1998) used. 500mg/l cefotoxime in ...

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

    African Journals Online (AJOL)

    Fermentation medium (by using sub-merged fermentation technique) was incubated for 48 h at 37°C temperature and agitation speed of 200 rpm. The protease was partially purified with 70% ammonium sulphate. Four different supports were used for the immobilization of the bacterial protease by physical adsorption ...

  5. Comparison of transgenic plant production for bacterial blight ...

    African Journals Online (AJOL)

    USER

    2010-03-29

    Mar 29, 2010 ... The study was carried out to improve bacterial leaf blight resistance in three rice cultivars (Basmati -. 370, DR - 82 and IR - 6) by Agrobacterium mediated transformation system. Three week-old scutellum derived calli were infected with Agrobacterium strain EHA101, containing binary vector pTCL5 which.

  6. Antinutrient and antioxidant quality of waxed and unwaxed pawpaw ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... and hydrolysable tannin (HT)) and antioxidant (vitamin C, tocopherol, total phenol and carotenoid) properties. Freshly ... The value of antinutrients of unwaxed sample was lower than that of waxed sample though there was no significant ... the Nigerian diet, but the production of these crops remain ...

  7. Diurnal variations in bacterial and viral production in Cochin estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, A.; Jasna, V.; Haridevi, C.K.; Jina, S.; Greeshma, M.; Breezy, J.; Nair, M.

    of bacterial production (BP) and viral production (VP) with respect to primary production over a diurnal period in Cochin estuary. Time series measurements were made every 2 h for 12 h (6 a.m.–6 p.m.) during periods of low and high salinities. The light...

  8. 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.

  9. 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...

  10. 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 bacterial growth rates, in most cases, both at 6 and 12 hours. The effect was most pronounced at pH 4.5. Chlorhexidine had significant (P bacterial growth and ammonia production. This technique, we describe, provides a pragmatic method for assessing the odor-inhibiting capacity of specific incontinence products.

  11. Optimization of the industrial production of bacterial aamylase in ...

    African Journals Online (AJOL)

    specific production rate, and the specific substrate consumption rate and also shortened the time necessary for maximum production of both biomass and enzyme. The increase in biomass either by prolonging the incubation time or by increasing aeration was accompanied by an increase in enzyme production. However ...

  12. 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

  13. 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 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 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.

  14. 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.

  15. Characterization of the contaminant bacterial communities in sugarcane first-generation industrial ethanol production.

    Science.gov (United States)

    Bonatelli, Maria L; Quecine, Maria C; Silva, Mariana S; Labate, Carlos A

    2017-09-15

    The industrial ethanolic fermentation process is operated in distilleries, either in fed-batch or continuous mode. A consequence of the large industrial ethanol production is bacterial contamination in the fermentation tanks, which is responsible for significant economic losses. To investigate this community, we accessed the profile of bacterial contaminant from two distilleries in Brazil, each operating a different fermentation mode, throughout sugarcane harvest of 2013-2014. Bacterial communities were accessed through Illumina culture-independent 16S rDNA gene sequencing, and qPCR was used to quantify total bacteria abundance. Both ethanol production modes showed similar bacterial abundance, around 105 gene copies/mL. 16S rDNA sequencing showed that 92%-99% of the sequences affiliated to Lactobacillus genus. Operational taxonomic units differently represented belonged mainly to Lactobacillus, but also to Weissella, Pediococcus, Acetobacter and Anaeosporobacter, although in lower abundance. Alpha-diversity only showed a correlation through the fermentation tanks in continuous mode, where it was always higher in the second and third tanks. Beta-diversity clearly separated the two distilleries and metagenome prediction reinforces clusterization within distilleries. Despite certain variations between bacterial community in the distilleries throughout harvest season, Lactobacillus were the main genera reported in both distilleries and bacterial community seemed to persist along time, suggesting bacterial reinfestation. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. 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...

  17. 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.

  18. 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

  19. Production and characterization of heavy-metal removing bacterial ...

    African Journals Online (AJOL)

    ... agents in the treatment of industrial wastewater effluents. Up to 250% increases in bioflocculant production were achieved by manipulation of the media composition. Increases in peptone and glycerol contents, up to 2 and 3%, respectively enhanced the bioflocculants production. With the exception of Herbaspirillium sp.

  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. Fungal and bacterial contaminants of six spices and spice products ...

    African Journals Online (AJOL)

    The spices and spice products collectively harboured Aeromonas salmonicida, Enterobacter cloacae, Enterobacter amnigenus, Enterobacter agglomerans, Enterobacter sakazakii, Flavobacterium sp, Chromobacterium violaceum, Pseudomonas putida, Pseudomonas aeroginosa, Acinetobacter sp, Pseudomonas cepacia, ...

  2. 21 CFR 184.1978 - Carnauba wax.

    Science.gov (United States)

    2010-04-01

    ... from the leaves and buds of the Brazilian wax palm Copernicia cerifera Martius. The wax is hard... fruits and fruit juices as defined in § 170.3(n)(35) of this chapter; and soft candy as defined in § 170...

  3. Sexual variation of bacterial microbiota of Dendroctonus valens guts and frass in relation to verbenone production.

    Science.gov (United States)

    Xu, Letian; Lu, Min; Xu, Dandan; Chen, Li; Sun, Jianghua

    2016-12-01

    Gut microbiota are widely involved in insect biology, and many factors can influence the microbiota in guts and frass. Dendroctonus valens is a very destructive forest pest in China, and the mass-attacking behavior is regulated by several semiochemicals, including verbenone, a multifunctional pheromone. The beetle harbors a variety of bacteria in its guts and frass and some of them are capable of verbenone production. D. valens is characterized by monogamy and female-initiated attacking behavior. Whether the bacterial communities fluctuate according to sex, and whether the variation influences the verbenone production, remains to be determined. In this study, the bacterial microbiota in D. valens guts and frass were analyzed, and verbenone production by their crude bacterial suspensions was compared in vitro. Bacterial diversity in female frass is more abundant compared to male frass, and the percentages and total amounts of main genera like Lactococcus and Pseudomonas in female frass are significantly higher than those in male frass. The verbenone produced by the female frass suspension is significantly higher than male frass. This study presents a comprehensive comparison of bacterial communities in guts and frass between both sexes of D. valens, highlighting the potential significance of female frass microbiota in verbenone production. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2017-03-01

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

  5. 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)

  6. 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.

  7. Assessment of different models to describe wax precipitation in flow assurance problems

    Energy Technology Data Exchange (ETDEWEB)

    Martos, C.; Coto, B.; Espada, J.J.; Robustillo, M.D. [Rey Juan Carlos Univ., Madrid (Spain). Dept. of Chemical and Environmental Technology; Pena, J.L. [Repsol-YPF, Madrid (Spain). Alfonso Cortina Technology Centre

    2008-07-01

    Paraffinic waxes found in crude oils cause flow assurance problems because these compounds can precipitate when temperature decreases during oil production, transport through pipelines or storage. The key variables involved in the wax precipitation process are the wax appearance temperature (WAT) and the wax precipitation curve (WPC). A good understanding of the liquid-solid equilibrium is required in order to model the precipitation process. However, new experimental data is needed to address this issue, particularly the composition of the raw crude oil, the amount of precipitated waxes against temperature and the nature of such waxes. Most models available in the literature require the knowledge of the n-paraffin distribution of crude oil. This type of determination can be carried out using different chromatographic techniques. In this study, experimental WAT and WPC were determined by means of a recently developed multistage fractional precipitation procedure. The trapped crude oil of the precipitated mixtures at each temperature was determined by the 1H NMR technique to determine the true amount of wax precipitated at each temperature. The n-paraffin distribution for the chosen crude oils was determined by chromatographic techniques. The predictive capabilities of the available models was verified by comparing experimental and predicted results. 3 refs.

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

    African Journals Online (AJOL)

    SAM

    2014-05-21

    May 21, 2014 ... degrade starch in random fashion producing various maltooligosaccharide mixtures (Mamo et al., 1999;. Sarikaya and Gurgun, 2000; Kiran and Chandra, 2008). Conclusion. The results in this study indicated that isolate W74 was a potential strain for α-amylase production under solid state fermentation ...

  9. 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 ...

  10. Production of bacterial amylase by Bacillus species isolated from ...

    African Journals Online (AJOL)

    Optimum pH activity was obtained at 4.0 with a concentration of 0.376 mg/ml. Bacillus licheniformis has the greatest potential for producing amylase than the other isolates and rice husk can be exploited for amylase production. The B. licheniformis strain produced thermostable alpha-amylase with characteristics suitable for ...

  11. Quality assurance in the egg production chain to reduce the bacterial contamination of the eggshell.

    Science.gov (United States)

    De Reu, K; Grijspeerdt, K; Heyndrickx, M; Uyttendaele, M; Herman, L

    2003-01-01

    Washing eggs in sterile plastic bags with diluent is an efficient sample preparation method for the determination of the bacterial contamination on eggshells. The total count of aerobic bacteria and the total count of Gramnegative bacteria on the eggshell can be used to detect critical contamination points in the egg production chain. The number of eggs to be sampled in a point of the production chain was determined on a statistical basis and fixed on 40 for non-graded eggs and on 20 for graded eggs. In two production chains, one cage production and one organic production system, critical contamination points were identified. The influence of the housing system on the bacterial contamination of the eggshell at the stable was studied. A positive correlation was found between the initial bacterial eggshell contamination and the concentration of bacteria in the air of the poultry houses. With the exception of heavily soiled shells, like shells from ground eggs, there is a poor correlation between the level of bacterial contamination and the visual eggshell contamination.

  12. 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

  13. Application of Bacterial Laccases for Sustainable Energy Production

    DEFF Research Database (Denmark)

    Lörcher, Samuel; Koschorreck, Katja; Shipovskov, Stepan

    for a number of special applications, such as disposable implantable power suppliers for medical sensor-transmitters and drug delivery/activator systems and self-powered enzyme-based biosensors; and they do offer practical advantages of using abundant organic raw materials for clean and sustainable energy...... production. Progress in enzyme biotechnology and electrochemistry enables now construction of biofuel cells exploiting a wide spectrum of enzymes wired to electrodes, able of prolonged for up to several months function.1-3 One of the most attractive designs exploits direct electronic communication between...

  14. 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.

  15. Filter Cake Oil-Wax as Raw Material for the Production of Biodiesel: Analysis of the Extraction Process and the Transesterification Reaction

    OpenAIRE

    L. Casas; Y. Hernández; C. Mantell; N. Casdelo; E. Martinez de la Ossa

    2015-01-01

    The viability of using the waste obtained in the manufacture of sugar from sugarcane for the production of biodiesel has been analyzed. Two fundamental stages are necessary to obtain biodiesel; the first stage is the extraction process from the waste oil materials and the second is the transesterification reaction. Four techniques, Soxhlet, orbital shaker extraction, ultrasonic-assisted extraction, and supercritical fluid extraction, have been analyzed. For Soxhlet, orbital shaker extraction,...

  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. 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

  18. Production of metabolites as bacterial responses to the marine environment.

    Science.gov (United States)

    de Carvalho, Carla C C R; Fernandes, Pedro

    2010-03-17

    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 Fe(3+) 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 hydrocarbon

  19. 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

    and economically-feasible strategy for the production of novel high-value phenolic compounds isolated from berry fruits using bacterial platforms. The project aimed at covering all stages of the discovery and pre-commercialization process, including berry collection, screening and characterization......-up of production by fermentation up to pilot scale, as well as societal and economic analyses of the processes. This review article summarizes some of the key findings obtained throughout the duration of the project....

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

    Science.gov (United States)

    Berdjeb, Lyria; Pollet, Thomas; Domaizon, Isabelle; Jacquet, Stéphan

    2011-04-29

    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. The presence of grazers (i.e. stimulation of viral production (compared to the treatment with no eukaryotic predators) was more variable between lakes than between seasons, with the highest value having been recorded in the mesotrophic lake (+30%). Viral lysis and grazing activities acted additively to sustain high bacterial production in all experiments. Nevertheless, the stimulation of bacterial production was more variable between seasons than between lakes, with the highest values obtained in summer (+33.5% and +37.5% in Lakes Bourget and Annecy, respectively). The presence of both predators (nanoflagellates and viruses) did not seem to have a clear influence upon bacterial community structure according to the four experiments. Our results highlight the importance of a synergistic effect, i.e. the

  1. 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...

  2. 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.

  3. Modulation of bacterial ghosts--induced nitric oxide production in macrophages by bacterial ghost-delivered resveratrol.

    Science.gov (United States)

    Koller, Verena J; Dirsch, Verena M; Beres, Hortenzia; Donath, Oliver; Reznicek, Gottfried; Lubitz, Werner; Kudela, Pavol

    2013-03-01

    The present study aimed to investigate the capacity of resveratrol (RV) delivered into macrophages by bacterial ghosts (BGs), representing intact empty nonliving envelopes of Gram-negative bacteria, to modulate nitric oxide (NO) production related to the presence of the pathogen-associated molecular patterns on the surface of BGs. Incubation of the murine macrophage cell line RAW 264.7 with BGs leads to a dose-dependent activation of inducible NO synthase. To modify BG-induced NO formation in RAW 264.7 cells by RV; BGs were loaded with RV (RV-BGs) and incubated with murine macrophages in a dose-dependent manner. RV-BGs delivering RV to the target macrophages significantly reduced BG-induced NO production with concentration of RV more than one order of magnitude lower than the amount of RV capable of reducing NO formation when applied directly. Moreover, no cytotoxic impact of BGs on the viability of RAW 264.7 cells added to macrophages alone or loaded with RV was detected after a mutual 24 h incubation, whereas cell viability slightly decreased (~ 10%) when RV concentrations of 30 μm alone were applied. The results obtained in the present study clearly indicate that the intracellular delivery of RV by BGs significantly enhances the total RV effect. © 2012 The Authors Journal compilation © 2012 FEBS.

  4. Wax extraction from filter Cake with Ethanol 96 ºGL at Laboratory Scale

    Directory of Open Access Journals (Sweden)

    Inés María San Anastacio-Rebollar

    2017-01-01

    Full Text Available This article proposes a methodology for the production of wax starting from the sugar cane phlegm, in which aggressive substances to the environment are not used. The wax is extracted from the phlegm, a residue of the sugar industry, by using ethanol (with a purity of 96 ºGL as a solvent. A methodology to achieve the extraction of wax from the filter cake was determined. A filter cake:ethanol ratio, where for every 0,05 kg of filter cake: 1L of ethanol was used. The operation parameters of extraction of temperature of 70 ºC, atmospheric pressure, speed of agitation 700 rpm and extraction time 2,5 hour were defined. Under the above mentioned conditions 86,17 % of extraction was achieved. The obtained wax presented the necessary characteristics to compete in the market of vegetable wax. In order to evaluate the design viability of a demonstrative plant for wax production, a simulation of the complete process with the professional simulation software (Super Pro Design was performed. Laboratory obtained results were used for this simulation.

  5. Wax deposition measurement under turbulent flow conditions for a live waxy crude from Turkmenistan

    Energy Technology Data Exchange (ETDEWEB)

    Akbarzadeh, K.; Ratulowski, J.; Davies, T. [Schlumberger, Edmonton, AB (Canada). DBR Technology Center; Norpiah, R.M. [Petronas (Malaysia)

    2008-07-01

    The challenges facing deepwater oil production were discussed, with particular reference to flow assurance problems caused by cold temperatures and long offsets that impact the flow of fluids from the wellbore to the export line. The precipitation and deposition of waxy material is one of the most pervasive flow assurance issues. In order to develop operating strategies that address flow assurance risks while minimizing capital and operating costs, it is important to obtain fluid property data and phase behaviour data. Conventional deposition testing for wax is typically run on dead oil in a low shear environment. However, the flow regime in a production system is turbulent with high wall shears because the oil, gas and water are at elevated pressures. As such, wax deposition data for dead oil taken under laminar flow conditions overpredicts the actual wax deposition rates observed at field conditions. Therefore, a high-pressure deposition cell was used in this study to investigate the deposition tendency of a waxy crude oil from Turkmenistan at field conditions. The study also examined the influence of flow rate, temperature and wax inhibitors on wax deposition. The effect of solution gas was also determined. A method for scaling the deposition cell data to pipe flow was also presented and used in a multiphase flow simulator to predict the wax deposition profile in the field.

  6. Improve Toolmarks' Impressions in Soft Wax.

    Science.gov (United States)

    Finkelstein, Nir; Volkov, Nikolai; Tsach, Tsadok

    2017-05-01

    When the forensic toolmarks laboratory receives for examination and comparison a tool that is suspected of having been involved in a crime, the expert performs tests designed to determine whether or not the specific tool generates the same toolmarks as those found at the crime scene. This is performed by testing tool striation on a piece of soft metal, such as lead, and examining the marks left by the tool. Studies have shown that wax may be an optimal material for this purpose. This study examines the use of wax at different temperatures and shows that quality of results is better when the wax is cooled (recommended temperature is -18°C). At this temperature, the wax is flexible enough but does not smear and is not sticky. This makes the obtained marks clearer and of better quality. © 2017 American Academy of Forensic Sciences.

  7. 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

  8. Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production.

    Science.gov (United States)

    Simon-Colin, Christelle; Gueguen, Yannick; Bachere, Evelyne; Kouzayha, Achraf; Saulnier, Denis; Gayet, Nicolas; Guezennec, Jean

    2015-06-11

    Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with two marine bacterial exopolymers as alternative treatment agents. In field studies, the combination treatment resulted in a significant reduction in graft failures vs. untreated controls. The combination of tachyplesin (73 mg/L) with two bacterial exopolysaccharides (0.5% w/w) acting as filming agents, reduces graft-associated bacterial contamination. The survival data were similar to that reported for antibiotic treatments. These data suggest that non-antibiotic treatments of pearl oysters may provide an effective means of improving oyster survival following grafting procedures.

  9. 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.

  10. Contribution of dinitrogen fixation to bacterial and primary productivity in the Gulf of Aqaba (Red Sea)

    Science.gov (United States)

    Rahav, E.; Herut, B.; Mulholland, M. R.; Voß, B.; Stazic, D.; Steglich, C.; Hess, W. R.; Berman-Frank, I.

    2013-06-01

    We evaluated the seasonal contribution of heterotrophic and autotrophic diazotrophy to the total dinitrogen (N2) fixation in a representative pelagic station in the northern Gulf of Aqaba in early spring when the water column was mixed and during summer under full thermal stratification. N2 fixation rates were low during the mixed period (˜ 0.1 nmol N L-1 d-1) and were significantly coupled with both primary and bacterial productivity. During the stratified period N2 fixation rates were four-fold higher (˜ 0.4 nmol N L-1 d-1) and were significantly correlated solely with bacterial productivity. Furthermore, while experimental enrichment of seawater by phosphorus (P) enhanced bacterial productivity and N2 fixation rates during both seasons primary productivity was stimulated by P only in the early spring. Metatranscriptomic analyses from the stratified period identified the major diazotrophic contributors as related to heterotrophic prokaryotes from the Euryarchaeota and Desulfobacterales (Deltaproteobacteria) or Chlorobiales (Chlorobia). Moreover, during this season, experimental amendments to seawater applying a combination of the photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and a mixture of amino acids increased both bacterial productivity and N2 fixation rates. Our findings from the northern Gulf of Aqaba indicate a~shift in the diazotrophic community from phototrophic and heterotrophic populations, including small blooms of the cyanobacterium Trichodesmium, in winter/early spring, to predominantly heterotrophic diazotrophs in summer that may be both P and carbon limited as the additions of P and amino acids illustrated.

  11. Identification of the bacterial microflora in dairy products by temporal temperature gradient gel electrophoresis.

    Science.gov (United States)

    Ogier, Jean-Claude; Son, Olivier; Gruss, Alexandra; Tailliez, Patrick; Delacroix-Buchet, Agnes

    2002-08-01

    Numerous microorganisms, including bacteria, yeasts, and molds, are present in cheeses, forming a complex ecosystem. Among these organisms, bacteria are responsible for most of the physicochemical and aromatic transformations that are intrinsic to the cheesemaking process. Identification of the bacteria that constitute the cheese ecosystem is essential for understanding their individual contributions to cheese production. We used temporal temperature gradient gel electrophoresis (TTGE) to identify different bacterial species present in several dairy products, including members of the genera Lactobacillus, Lactococcus, Leuconostoc, Enterococcus, Pediococcus, Streptococcus, and Staphylococcus. The TTGE technique is based on electrophoretic separation of 16S ribosomal DNA (rDNA) fragments by using a temperature gradient. It was optimized to reveal differences in the 16S rDNA V3 regions of bacteria with low-G+C-content genomes. Using multiple control strains, we first set up a species database in which each species (or group of species) was characterized by a specific TTGE fingerprint. TTGE was then applied to controlled dairy ecosystems with defined compositions, including liquid (starter), semisolid (home-made fermented milk), and solid (miniature cheese models) matrices. Finally, the potential of TTGE to describe the bacterial microflora of unknown ecosystems was tested with various commercial dairy products. Subspecies, species, or groups of species of lactic acid bacteria were distinguished in dairy samples. In conclusion, TTGE was shown to distinguish bacterial species in vitro, as well as in both liquid and solid dairy products.

  12. Dual-label radioisotope method for simultaneously measuring bacterial production and metabolism in natural waters

    International Nuclear Information System (INIS)

    Jonas, B.J.; Tuttle, J.H.; Stoner, D.L.; Ducklow, H.W.

    1988-01-01

    Bacterial production and amino acid metabolism in aquatic systems can be estimated by simultaneous incubation of water samples with both tritiated methyl-thymidine and 14 C-labeled amino acids. This dual-label method not only saves time, labor, and materials, but also allows determination of these two parameters in the same microbial subcommunity. Both organic carbon incorporation and respiration can be estimated. The method is particularly suitable for large-scale field programs and has been used successfully with eutrophic estuarine samples as well as with oligotrophic oceanic water. In the mesohaline portion of Chesapeake Bay, thymidine incorporation ranged seasonally from 2 to 635 pmol liter -1 h -1 and amino acid turnover rates ranged from 0.01 to 28.4% h -1 . Comparison of thymidine incorporation with amino acid turnover measurements made at a deep, midbay station in 1985 suggested a close coupling between bacterial production and amino acid metabolism during most of the year. However, production-specific amino acid turnover rates increased dramatically in deep bay waters during the spring phytoplankton bloom, indicating transient decoupling of bacterial production from metabolism. Ecological features such as this are readily detectable with the dual-label method

  13. Generate a bioactive natural product library by mining bacterial cytochrome P450 patterns.

    Science.gov (United States)

    Liu, Xiangyang

    2016-06-01

    The increased number of annotated bacterial genomes provides a vast resource for genome mining. Several bacterial natural products with epoxide groups have been identified as pre-mRNA spliceosome inhibitors and antitumor compounds through genome mining. These epoxide-containing natural products feature a common biosynthetic characteristic that cytochrome P450s (CYPs) and its patterns such as epoxidases are employed in the tailoring reactions. The tailoring enzyme patterns are essential to both biological activities and structural diversity of natural products, and can be used for enzyme pattern-based genome mining. Recent development of direct cloning, heterologous expression, manipulation of the biosynthetic pathways and the CRISPR-CAS9 system have provided molecular biology tools to turn on or pull out nascent biosynthetic gene clusters to generate a microbial natural product library. This review focuses on a library of epoxide-containing natural products and their associated CYPs, with the intention to provide strategies on diversifying the structures of CYP-catalyzed bioactive natural products. It is conceivable that a library of diversified bioactive natural products will be created by pattern-based genome mining, direct cloning and heterologous expression as well as the genomic manipulation.

  14. 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.

  15. Side effects of extra tRNA supplied in a typical bacterial protein production scenario

    DEFF Research Database (Denmark)

    Søgaard, Karina Marie; Nørholm, Morten H. H.

    2016-01-01

    Recombinant protein production is at the core of biotechnology and numerous molecular tools and bacterial strains have been developed to make the process more efficient. One commonly used generic solution is to supply extra copies of low-abundance tRNAs to compensate for the presence of complemen......Recombinant protein production is at the core of biotechnology and numerous molecular tools and bacterial strains have been developed to make the process more efficient. One commonly used generic solution is to supply extra copies of low-abundance tRNAs to compensate for the presence...... of complementary rare codons in genes-of-interest. Here we show that such extra tRNA, supplied by the commonly used pLysSRARE2 plasmid, can cause two side effects: (1) growth and gene expression can be impaired, and (2) apparent positive effects can be caused by differential expression of the lysozyme gene encoded...... on the same plasmid and not the tRNAs per se. These phenomena seem to have been largely overlooked despite the huge popularity of the T7/pET-based systems for bacterial protein production....

  16. 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)

  17. 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

  18. Recombinant plants provide a new approach to the production of bacterial polysaccharide for vaccines.

    Directory of Open Access Journals (Sweden)

    Claire M Smith

    Full Text Available 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.

  19. Bacterial dynamics during yearlong spontaneous fermentation for production of ngari, a dry fermented fish product of Northeast India.

    Science.gov (United States)

    Devi, Khunjamayum Romapati; Deka, Manab; Jeyaram, Kumaraswamy

    2015-04-16

    Ngari is the most popular traditionally processed non-salted fish product, prepared from sun-dried small cyprinid fish Puntius sophore (Ham.) in Manipur state of Northeast India. The microbial involvement in ngari production remained uncertain due to its low moisture content and yearlong incubation in anaerobically sealed earthen pots without any significant change in total microbial count. The culture-independent PCR-DGGE analysis used during this study confirmed a drastic bacterial community structural change in comparison to its raw material. To understand the bacterial dynamics during this dry fermentation, time series samples collected over a period of nine months through destructive sampling from two indigenous ngari production centres were analysed by using both culture-dependent and culture-independent molecular methods. A total of 210 bacteria isolated from the samples were identified by amplified ribosomal DNA restriction analysis (ARDRA) based grouping and 16S rRNA gene sequence similarity analysis. The dominant bacteria were Staphylococcus cohnii subsp. cohnii (38.0%), Tetragenococcus halophilus subsp. flandriensis (16.8%), a novel phylotype related to Lactobacillus pobuzihii (7.2%), Enterococcus faecium (7.2%), Bacillus indicus (6.3%) and Staphylococcus carnosus (3.8%). Distinct bacterial dynamics with the emergence of T. halophilus at third month (10(6)CFU/g), L. pobuzihii at sixth month (10(6)CFU/g), S. carnosus at three to six months (10(4)CFU/g) and B. indicus at six to nine months (10(5)CFU/g) in both the production centres was observed during ngari fermentation. However, the other two dominant bacteria S. cohnii and E. faecium were isolated throughout the fermentation with the population of 10(6)CFU/g and 10(4)CFU/g respectively. Culture-independent PCR-DGGE analysis further showed the presence of additional species, in which Kocuria halotolerans and Macrococcus caseolyticus disappeared during fermentation while Clostridium irregulare and

  20. Coatings and films derived from clay/wax nanocomposites

    Science.gov (United States)

    Chaiko, David J.; Leyva, Argentina A.

    2006-11-14

    The invention provides methods for making clay/wax nanocomposites and coatings and films of same with improved chemical resistance and gas barrier properties. The invention further provides methods for making and using emulsions of such clay/wax nanocomposites. Typically, an organophillic clay is combined with a wax or wax/polymer blend such that the cohesion energy of the clay matches that of the wax or wax/polymer blend. Suitable organophilic clays include mica and phyllosilicates that have been surface-treated with edge or edge and surface modifying agents. The resulting nanocomposites have applications as industrial coatings and in protective packaging.

  1. 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.

  2. Application of Recombinant Factor C Reagent for the Detection of Bacterial Endotoxins in Pharmaceutical Products.

    Science.gov (United States)

    Bolden, Jay; Smith, Kelly

    2017-01-01

    Recombinant Factor C (rFC) is non-animal-derived reagent used to detect bacterial endotoxins in pharmaceutical products. Despite the fact that the reagent was first commercially available nearly 15 years ago, the broad use of rFC in pharmaceutical industry has long been lagging, presumably due to historical single-source supplier concerns and the lack of inclusion in worldwide pharmacopeias. Commercial rFC reagents are now available from multiple manufacturers, thus single sourcing is no longer an issue. We report here the successful validation of several pharmaceutical products by an end-point florescence-based endotoxin method using the rFC reagent. The method is equivalent or superior to the compendia bacterial endotoxins test method. Based on the comparability data and extenuating circumstances, the incorporation of the end point fluorescence technique and rFC reagent in global compendia bacterial endotoxins test chapters is desired and warranted. LAY ABSTRACT: Public health has been protected for over 30 years with the use of a purified blood product of the horseshoe crab, limulus amebocyte lysate. More recently, this blood product can be produced in biotech manufacturing processes, which reduces potential impacts to the horseshoe crab and related species dependent upon the crab, for example, migrating shorebirds. The pharmaceutical industry has been slow to adopt the use of this reagent, Recombinant Factor C (rFC), for various reasons. We evaluated the use of rFC across many pharmaceutical products, and in other feasibility demonstration experiments, and found rFC to be a suitable alternative to the animal-derived limulus amebocyte lysate. Incorporation of rFC and its analytical method into national testing standards would provide an equivalent or better test while continuing to maintain patient safety for those who depend on medicines and while securing pharmaceutical supply chains. In addition, widespread use of this method would benefit existing animal

  3. 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

  4. Production of peptone from boso fish (Oxyeleotris marmorata) for bacterial growth medium

    Science.gov (United States)

    Priatni, S.; Kosasih, W.; Budiwati, T. A.; Ratnaningrum, D.

    2017-03-01

    Underutilized Oxyeleotris marmorata fish is abundant and widespread in Indonesia. The study aimed to use O. marmorata fish for peptone production using papain from dried latex of papaya fruit. The peptone was applied as nitrogen sources for bacterial growth. The resulted peptone was optimized at 50-65°C for 5-8 hr, using 0.1% of papain at pH 6.0. Characterization of peptone was based on the soluble protein content, N-amino content, % degree hydrolysis (DH), SDS PAGE profile and growth of bacteria Escherichia coli and Staphylococcus aureus. The results indicated that the optimum condition for hydrolysis was at 50°C for 7 hr (p electrophoresis (SDS PAGE) profile of peptone showed a major band with molecular weight between 17-28 kDa. Fish peptone effectiveness for E. coli and S. aureus growth was similar with commercial bacterial peptone.

  5. 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.

  6. Bacterial Glycosyltransferases: Challenges and Opportunities of a Highly Diverse Enzyme Class Toward Tailoring Natural Products.

    Science.gov (United States)

    Schmid, Jochen; Heider, Dominik; Wendel, Norma J; Sperl, Nadine; Sieber, Volker

    2016-01-01

    The enzyme subclass of glycosyltransferases (GTs; 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 GTs also catalyze the transfer of sugar moieties onto aglycons, which is of great relevance for the synthesis of many high value natural products. Bacterial GTs show a higher sequence similarity in comparison to mammalian ones. Even when most GTs 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 GTs, 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.

  7. 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.

  8. Effect of media components on cell growth and bacterial cellulose production from Acetobacter aceti MTCC 2623.

    Science.gov (United States)

    Dayal, Manmeet Singh; Goswami, Navendu; Sahai, Anshuman; Jain, Vibhor; Mathur, Garima; Mathur, Ashwani

    2013-04-15

    Acetobacter aceti MTCC 2623 was studied as an alternative microbial source for bacterial cellulose (BC) production. Effect of media components on cell growth rate, BC production and cellulose characteristics were studied. FTIR results showed significant variations in cellulose characteristics produced by A. aceti in different media. Results have shown the role of fermentation time on crystallinity ratio of BC in different media. Further, effect of six different media components on cell growth and BC production was studied using fractional factorial design. Citric acid was found to be the most significant media component for cell growth rate (95% confidence level, R(2)=0.95). However, direct role of these parameters on cellulose production was not established (p-value>0.05). Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. The Tripod for Bacterial Natural Product Discovery: Genome Mining, Silent Pathway Induction, and Mass Spectrometry-Based Molecular Networking.

    Science.gov (United States)

    Trivella, Daniela B B; de Felicio, Rafael

    2018-01-01

    Natural products are the richest source of chemical compounds for drug discovery. Particularly, bacterial secondary metabolites are in the spotlight due to advances in genome sequencing and mining, as well as for the potential of biosynthetic pathway manipulation to awake silent (cryptic) gene clusters under laboratory cultivation. Further progress in compound detection, such as the development of the tandem mass spectrometry (MS/MS) molecular networking approach, has contributed to the discovery of novel bacterial natural products. The latter can be applied directly to bacterial crude extracts for identifying and dereplicating known compounds, therefore assisting the prioritization of extracts containing novel natural products, for example. In our opinion, these three approaches-genome mining, silent pathway induction, and MS-based molecular networking-compose the tripod for modern bacterial natural product discovery and will be discussed in this perspective.

  10. Bacterial production in the water column of small streams highly depends on terrestrial dissolved organic carbon

    Science.gov (United States)

    Graeber, Daniel; Poulsen, Jane R.; Rasmussen, Jes J.; Kronvang, Brian; Zak, Dominik; Kamjunke, Norbert

    2016-04-01

    In the recent years it has become clear that the largest part of the terrestrial dissolved organic carbon (DOC) pool is removed on the way from the land to the ocean. Yet it is still unclear, where in the freshwater systems terrestrial DOC is actually taken up, and for streams DOC uptake was assumed to happen mostly at the stream bottom (benthic zone). However, a recent monitoring study implies that water column but not benthic bacteria are strongly affected by the amount and composition of DOM entering streams from the terrestrial zone. We conducted an experiment to compare the reaction of the bacterial production and heterotrophic uptake in the water column and the benthic zone to a standardized source of terrestrial DOC (leaf leachate from Beech litter). In detail, we sampled gravel and water from eight streams with a gradient in stream size and land use. For each stream four different treatments were incubated at 16°C for three days and each stream: filtered stream water with gravel stones (representing benthic zone bacteria) or unfiltered stream water (representing water column bacteria), both either with (n = 5) or, without (n = 3) leaf leachate. We found that the bacterial uptake of leaf litter DOC was higher for the benthic zone likely due to the higher bacterial production compared to the water column. In contrast, the bacterial production per amount of leaf leachate DOC taken up was significantly higher for the bacteria in the water column than for those in the benthic zone. This clearly indicates a higher growth efficiency with the leaf leachate DOC for the bacteria in the water column than in the benthic zone. We found a high variability for the growth efficiency in the water column, which was best explained by a negative correlation of the DOC demand with stream width (R² = 0.86, linear correlation of log-transformed data). This was not the case for the benthic zone bacteria (R² = 0.02). This implies that water column bacteria in very small streams

  11. 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.

  12. 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.)

  13. 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.

  14. 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.

  15. Soil Bacterial Diversity and Productivity of Coffee - Shade Tree Agro-ecosystems

    Directory of Open Access Journals (Sweden)

    Rusdi Evizal

    2012-05-01

    Full Text Available Coffee productions should have environmental values such as providing high soil microbial diversity while producinghigh yield. To examine that purposes, two experimental plots were constucted at benchmark site of Conservationand Sustainable Management of Below-Ground Biodiversity (CSM-BGBD, in Sumberjaya Subdistrict, WestLampung, Indonesia, during 2007-2010. Types of coffee agro-ecosystem to be examined were Coffea canephorawith shade trees of Gliricidia sepium, Erythrina sububrams, Michelia champaca, and no shade. Two plots wereconstructed at 5-years-coffee and 15-years-coffee. Diversity of soil bacteria was determined based on DNA fingerprinting of total soil bacteria using Ribosomal Intergenic Spacer Analysis (RISA method. The results showed that:(1 For mature coffee (15 years old, shade-grown coffee agro-ecosystems had higher soil bacterial diversity thanthose of no shade coffee agro-ecosystem, (2 Shaded coffee agro-ecosystems were able to conserve soil bacterialdiversity better than no-shade coffee agro-ecosystem. Soil organic C and total litter biomass had positive effect onsoil bacterial diversity, (3 Types of agro-ecosystem significantly affected the bean yield of 15 years coffee. Coffeeagro-ecosystems shaded by legume trees had higher yield than those of non-legume shade and no shade coffeeagro-ecosystem, (4 Shannon-Weaver indices of soil bacterial diversity together with weed biomass and N contentof coffee leaf had positive effect on coffee bean yield.

  16. 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.

  17. The composition of wax and oil in green coffee beans

    NARCIS (Netherlands)

    Folstar, P.

    1976-01-01

    Methods for the isolation of wax and oil from green coffee beans were studied and a method for the quantitative extraction of coffee oil from the beans was introduced. Coffee wax, coffee oil and wax-free coffee oil as well as the unsaponifiable matter prepared from each were fractionated by column

  18. Investigation of drug release from carnauba wax matrices: a case ...

    African Journals Online (AJOL)

    A study was carried out to assess the effect of carnauba wax particle size on sustained release characteristics, the effect of drug loading on release and the kinetics of propranolol hydrochloride release from carnauba wax matrices. The results obtained showed that small particles (180 250 µ m) of carnauba wax had superior ...

  19. Investigation of synthetic spermaceti wax as a potential oral ...

    African Journals Online (AJOL)

    The present study was aimed at investigating drug release from spermaceti wax matrices. Materials such as ethylcellulose and methylcellulose were incorporated into the spermaceti wax matrices and release was evaluated. Spermaceti wax can form matrices that release drug in a sustained release fashion. Higuchi or first ...

  20. 75 FR 63200 - Petroleum Wax Candles From China

    Science.gov (United States)

    2010-10-14

    ... COMMISSION Petroleum Wax Candles From China AGENCY: United States International Trade Commission. ACTION: Scheduling of an expedited five-year review concerning the antidumping duty order on petroleum wax candles... whether revocation of the antidumping duty order on petroleum wax candles from China would be likely to...

  1. 75 FR 80843 - Petroleum Wax Candles From China

    Science.gov (United States)

    2010-12-23

    ... COMMISSION Petroleum Wax Candles From China Determination On the basis of the record \\1\\ developed in the... antidumping duty order on petroleum wax candles from China would be likely to lead to continuation or... Petroleum Wax Candles from China: Investigation No. 731-TA-282 (Third Review). Issued: December 17, 2010. By...

  2. Natural Products at Work: Structural Insights into Inhibition of the Bacterial Membrane Protein MraY.

    Science.gov (United States)

    Koppermann, Stefan; Ducho, Christian

    2016-09-19

    Natural(ly) fit: The X-ray crystal structure of the bacterial membrane protein MraY in complex with its natural product inhibitor muraymycin D2 is discussed. MraY catalyzes one of the membrane-associated steps in peptidoglycan biosynthesis and, therefore, represents a promising target for novel antibiotics. Structural insights derived from the protein-inhibitor complex might now pave the way for the development of new antimicrobial drugs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. 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).

  4. Study on process development of solvent extraction of montan wax from lignite particles in a continuous fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Tiejun; Zhao Lianzhong; Di Weiquan; Huang Zhe; Chen Dabao; Zhang Ruiying; Yuan Huiru; Yang Guilin

    1985-12-01

    A new process of continuous solvent extraction for production of montan wax based on particulate fluidization technology was developed. Experimental results obtained in the pilot plant show that the fluidised bed extraction process is successful. The extraction rate is about 65-70% and benzene consumption is 0.46 t per ton of wax. Xun Dian lignite with particle size of 0.2-3 mm was used, which gave the following analysis data: wax content 7.15%, water content about 23%, ash content 12%. The quality of the montan wax product is specified as follows: water content 1.12%., insolubles (in benzene) 0.61%, ash content 0.3%, melting point 84 C, resin 21.16%, asphalts content 11.54%, acid value 35-50, saponification value 102.25.

  5. Epicuticular waxes and glaucousness of Encephalartos leaves

    NARCIS (Netherlands)

    Osborne, R; Stevens, JF

    The epicuticular leaf waxes from four glaucous and four non-glaucous species of Encephalartos were examined by GC-mass spectrometry and SEM techniques. The four glaucous-leaved species, E. horridus, E. lehmannii, E. princeps and E. trispinosus, all occurring in xeric conditions in the Eastern Cape

  6. 21 CFR 184.1976 - Candelilla wax.

    Science.gov (United States)

    2010-04-01

    ... practice: in chewing gum as defined in § 170.3(n)(6) of this chapter and in hard candy as defined in § 170... obtained from the candelilla plant. It is a hard, yellowish-brown, opaque-to-translucent wax. Candelilla...

  7. 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.

  8. 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

  9. Case Study: A Novel Bacterial Contamination in Cell Culture Production--Leptospira licerasiae.

    Science.gov (United States)

    Chen, Joseph; Bergevin, Jesse; Kiss, Robert; Walker, Gordon; Battistoni, Todd; Lufburrow, Patricia; Lam, Harry; Vinther, Anders

    2012-01-01

    Leptospira licerasiae, a novel bacterial contaminant found in Genentech cell culture manufacturing operations, poses a challenge to current microbial control strategies in upstream cell culture processes, as this microorganism is fully capable of passing through 0.1 μm sterilizing-grade filtration and is not detectable by standard microbiological methods described in major pharmaceutical compendia for microbial screening and quantification required for release of raw materials, in-process intermediates, and finished products in biopharmaceutical production. The root cause investigation was greatly aided by the genetic identification of the contaminant and subsequent confirmation by cultural method and real-time polymerase chain reaction assay from the affected product batches. The purpose of this case study is to share knowledge on the novel contaminant, L. licerasiae, and potential routes of contamination in the cell culture manufacturing environment from a series of investigations involving root cause analysis, impact assessments, risk assessment, and global corrective and preventative action, as well as to provide guidance on the detection and prevention of Leptospira contamination with the intent to aid the industry to continually improve microbial control strategies for the benefit of patients. Leptospira licerasiae, a novel bacterial contaminant found in cell culture manufacturing operations, poses a challenge to current microbial control strategies in upstream cell culture processes because this microorganism is capable of passing through 0.1 μm sterilizing-grade membrane filters and is not detectable by standard microbiological methods used in biopharmaceutical production. The root cause investigation was greatly aided by the genetic identification of the contaminant and subsequent confirmation by cultural method and real-time polymerase chain reaction assay from the affected product batches. The purpose of this case study is to share knowledge on the

  10. 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.

  11. Green mitigation strategy for cultural heritage: bacterial potential for biocide production.

    Science.gov (United States)

    Silva, Mara; Rosado, Tânia; Teixeira, Dora; Candeias, António; Caldeira, Ana Teresa

    2017-02-01

    Several biosurfactants with antagonistic activity are produced by a variety of microorganisms. Lipopeptides (LPPs) produced by some Bacillus strains, including surfactin, fengycin and iturin are synthesized nonribosomally by mega-peptide synthetase (NRPS) units and they are particularly relevant as antifungal agents. Characterisation, identification and evaluation of the potentials of several bacterial isolates were undertaken in order to establish the production of active lipopeptides against biodeteriogenic fungi from heritage assets. Analysis of the iturin operon revealed four open reading frames (ORFs) with the structural organisation of the peptide synthetases. Therefore, this work adopted a molecular procedure to access antifungal potential of LPP production by Bacillus strains in order to exploit the bioactive compounds synthesis as a green natural approach to be applied in biodegraded cultural heritage context. The results reveal that the bacterial strains with higher antifungal potential exhibit the same morphological and biochemical characteristics, belonging to the genera Bacillus. On the other hand, the higher iturinic genetic expression, for Bacillus sp. 3 and Bacillus sp. 4, is in accordance with the culture antifungal spectra. Accordingly, the adopted methodology combining antifungal screening and molecular data is represent a valuable tool for quick identification of iturin-producing strains, constituting an effective approach for confirming the selection of lipopeptides producer strains.

  12. 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.

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

    Science.gov (United States)

    Meitz, Andrea; Sagmeister, Patrick; Lubitz, Werner; Herwig, Christoph; Langemann, Timo

    2016-03-24

    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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...... the technology and opening to new challenges. The design presented in this paper represents a step towards the development of a multi material deposition unit, able to selectively depose specific materials on demand in the same product, according to needs. In order to achieve that, waxes and respectivedesigns...... extruder principles of modularity and reconfigurability are also taken into account in order to ease up a subsequent integration with a more complex system....

  18. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to policosanols from sugar cane wax and maintenance of normal blood LDL-cholesterol concentrations (ID 1747, 1748, 1864, 1951, 1954, 4693) and maintenance of normal blood HDL-cholesterol concentrations (ID 1747, 1748, 1864, 1951, 1954, 4693) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    OpenAIRE

    Tetens, Inge

    2011-01-01

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health claims in relation to policosanols from sugar cane wax and maintenance of normal blood LDL-cholesterol concentrations and maintenance of normal blood HDL-cholesterol concentrations. The scientific substa...

  19. 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.)

  20. Pro-inflammatory Effects of Bacterial Recombinant Human C-Reactive Protein are Caused by Contamination with Bacterial Products not by C-Reactive Protein Itself

    Science.gov (United States)

    Pepys, Mark B.; Hawkins, Philip N.; Kahan, Melvyn C.; Tennent, Glenys A.; Gallimore, J. Ruth; Graham, David; Sabin, Caroline A.; Zychlinsky, Arturo; de Diego, Juana

    2006-01-01

    Intravenous administration to human volunteers of a commercial preparation of recombinant human C-reactive protein (CRP) produced in E. coli was recently reported in this journal to induce an acute phase response of serum amyloid A protein (SAA) and of CRP itself, and to activate the coagulation system. The authors concluded that CRP is probably a mediator of atherothrombotic disease. Here we confirm that this recombinant CRP preparation was pro-inflammatory both for mouse macrophages in vitro and for mice in vivo, but show that pure natural human CRP had no such activity. Furthermore mice transgenic for human CRP, and expressing it throughout their lives, maintained normal concentrations of their most sensitive endogenous acute phase reactants, SAA and serum amyloid P component (SAP). The patterns of in vitro cytokine induction and of in vivo acute phase stimulation by the recombinant CRP preparation were consistent with contamination by bacterial products, and there was 46.6 EU of apparent endotoxin activity per mg of CRP in the bacterial product, compared to 0.9 EU per mg of our isolated natural human CRP preparation. The absence of any pro-inflammatory activity in natural CRP for macrophages or healthy mice strongly suggests that the in vivo effects of the recombinant preparation observed in humans were due to pro-inflammatory bacterial products and not human CRP. PMID:16254214

  1. 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.

    Science.gov (United States)

    Dittrich, Sabine; Tadesse, Birkneh Tilahun; Moussy, Francis; Chua, Arlene; Zorzet, Anna; Tängdén, Thomas; Dolinger, David L; Page, Anne-Laure; Crump, John A; D'Acremont, Valerie; Bassat, Quique; Lubell, Yoel; Newton, Paul N; Heinrich, Norbert; Rodwell, Timothy J; González, Iveth J

    2016-01-01

    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 targeted and timely efforts by industry partners and academic institutions.

  2. 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

  3. 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.

  4. Role of epicuticular waxes in the susceptibility of cotton leaf curl ...

    African Journals Online (AJOL)

    use

    2011-12-05

    Dec 5, 2011 ... on Gossypium arboreum -786 plants, while lane 16,17 and 18 shows whiteflies on Gossypium hirsutum MNH-93. amplified from RCA product of whiteflies, G. hirsutum. MNH-93 plants and wax mutant GaWM3 plants but no amplification was observed in G. arboreum variety 786 as shown in Figure 5.

  5. 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

  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. Bacterial Biotransformation of Pentachlorophenol and Micropollutants Formed during Its Production Process

    Directory of Open Access Journals (Sweden)

    Eglantina Lopez-Echartea

    2016-11-01

    Full Text Available Pentachlorophenol (PCP is a toxic and persistent wood and cellulose preservative extensively used in the past decades. The production process of PCP generates polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs as micropollutants. PCDD/Fs are also known to be very persistent and dangerous for human health and ecosystem functioning. Several physico-chemical and biological technologies have been used to remove PCP and PCDD/Fs from the environment. Bacterial degradation appears to be a cost-effective way of removing these contaminants from soil while causing little impact on the environment. Several bacteria that cometabolize or use these pollutants as their sole source of carbon have been isolated and characterized. This review summarizes current knowledge on the metabolic pathways of bacterial degradation of PCP and PCDD/Fs. PCP can be successfully degraded aerobically or anaerobically by bacteria. Highly chlorinated PCDD/Fs are more likely to be reductively dechlorinated, while less chlorinated PCDD/Fs are more prone to aerobic degradation. The biochemical and genetic basis of these pollutants’ degradation is also described. There are several documented studies of effective applications of bioremediation techniques for the removal of PCP and PCDD/Fs from soil and sediments. These findings suggest that biodegradation can occur and be applied to treat these contaminants.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Fruit cuticular waxes as a source of biologically active triterpenoids.

    Science.gov (United States)

    Szakiel, Anna; Pączkowski, Cezary; Pensec, Flora; Bertsch, Christophe

    2012-06-01

    The health benefits associated with a diet rich in fruit and vegetables include reduction of the risk of chronic diseases such as cardiovascular disease, diabetes and cancer, that are becoming prevalent in the aging human population. Triterpenoids, polycyclic compounds derived from the linear hydrocarbon squalene, are widely distributed in edible and medicinal plants and are an integral part of the human diet. As an important group of phytochemicals that exert numerous biological effects and display various pharmacological activities, triterpenoids are being evaluated for use in new functional foods, drugs, cosmetics and healthcare products. Screening plant material in the search for triterpenoid-rich plant tissues has identified fruit peel and especially fruit cuticular waxes as promising and highly available sources. The chemical composition, abundance and biological activities of triterpenoids occurring in cuticular waxes of some economically important fruits, like apple, grape berry, olive, tomato and others, are described in this review. The need for environmentally valuable and potentially profitable technologies for the recovery, recycling and upgrading of residues from fruit processing is also discussed.

  13. Food additives reduce lactic acid bacterial growth in culture medium and in meat products, increasing product shelf life

    Directory of Open Access Journals (Sweden)

    Cleonice Mendes Pereira Sarmento

    2015-12-01

    Full Text Available The uncontrolled growth of lactic acid bacteria (LAB in meat and meat products leads to product spoilage, and thus shortens product shelf life. Although food additives are known to decrease LAB growth, this effect has not been analyzed in detail. Here, a detailed analysis was performed of the effects of sodium chloride, sodium polyphosphate, sodium lactate, sodium nitrite/nitrate, and garlic on the growth of the Lactobacillus plantarum in culture medium. The results were used to design and test experimental formulations of meat products. Initially, the effect of food additives on L. plantarum was evaluated using a Fractional Factorial Design (FFD, followed by a Central Composite Rotatable Design (CCRD. The Modified Gompertz Model was adjusted to the growth curves to determine the Kinetic parameters of bacterial growth (logarithmic increase in the population, specific growth rate, and lag phase extension. Higher sodium lactate and sodium chloride levels had a negative impact on L. plantarum growth parameters (p?0.05. Therefore, we designed experimental formulations of mortadella and smoked pork sausages containing 4% sodium lactate (w w-1 and 2.4-3.5% sodium chloride (w w-1, and determined LAB growth from samples of stored products produced according to these formulations, in order to determine product shelf life. There was an increased lag phase of LAB growth for most experimental formulations. Also, the experimental smoked pork sausages had a longer shelf life, which was increased by at least 22 days, suggesting that the proposed formulation, with higher than standard lactate concentration, increased the product’s shelf life.

  14. A novel bacterial expression method with optimized parameters for very high yield production of triple-labeled proteins.

    Science.gov (United States)

    Murray, Victoria; Huang, Yuefei; Chen, Jianglei; Wang, Jianjun; Li, Qianqian

    2012-01-01

    The Gram-negative bacterium Escherichia coli offer a means for rapid, high-yield, and economical production of recombinant proteins. However, when preparing protein samples for NMR, high-level production of functional isotopically labeled proteins can be quite challenging. This is especially true for the preparation of triple-labeled protein samples in D(2)O ((2)H/(13)C/(15)N). The large expense and time-consuming nature of triple-labeled protein production for NMR led us to revisit the current bacterial protein expression protocols. Our goal was to develop an efficient bacterial expression method for very high-level production of triple-labeled proteins that could be routinely utilized in every NMR lab without changing expression vectors or requiring fermentation. We developed a novel high cell-density IPTG-induction bacterial expression method that combines tightly controlled traditional IPTG-induction expression with the high cell-density of auto-induction expression. In addition, we optimize several key experimental protocols and parameters to ensure that our new high cell-density bacterial expression method routinely produces 14-25 mg of triple-labeled proteins and 15-35 mg of unlabeled proteins from 50-mL bacterial cell cultures.

  15. Developing novel bacterial based bioformulation having PGPR properties for enhanced production of agricultural crops.

    Science.gov (United States)

    Kalita, Munmi; Bharadwaz, Moonmee; Dey, Tapan; Gogoi, Kabita; Dowarah, Pallavi; Unni, Bala Gopalan; Ozah, Dibyajyoti; Saikia, Indira

    2015-01-01

    Plant growth promoting rhizobacteria (PGPR) are beneficial rhizobacteria which enhance plant growth as well as the productivity by a variety of mechanisms PGPR were isolated from the rhizosphere region of som plants (Machilus bombycina King) maintained at the Central Muga Eri Research and Training Institute, Lahdoigarh, Jorhat. A bacterial based bioformulation was prepared and sprayed over the experimental crops including tomato (Solanum lycopersicum), cauliflower (Brassica oleracea var botrytis), chili (Capsicum annuum) and brinjal (Solanum melongena). Biochemical analysis was done on these PGPR treated crops as well as the untreated crops. The bioformulations prepared from Bacillus cereus (MTCC 8297), Pseudomonas rhodesiae (MTCC 8299) and Pseudomonas rhodesiae (MTCC 8300) was found to be the most effective in increasing the shoot height, number of leaves, early fruiting and total biomass content of the plants after treatment.

  16. Conformational control of the bacterial Clp protease by natural product antibiotics.

    Science.gov (United States)

    Malik, I T; Brötz-Oesterhelt, H

    2017-07-06

    Covering: up to 2017The bacterial Clp protease is a highly conserved and structurally versatile machine. It has gained a lot of recognition during the last decade as a novel antibacterial drug target with an unprecedented mechanism of action. Due to its complexity, there are distinct means of interfering with its natural functions and several compounds targeting this machine have been identified. In this review, we summarize the current state of knowledge about natural products deregulating Clp proteolysis, a crucial and delicate process within the cell. Among those, acyldepsipeptide antibiotics of the ADEP class (ADEPs) are characterized best. The molecular mechanism of ADEP-mediated deregulation sheds light on the inner workings of the Clp protease.

  17. 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

  18. 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.

  19. Bacterial Indicator of Agricultural Management for Soil under No-Till Crop Production

    Science.gov (United States)

    Rosa, Silvina M.; Simonetti, Leandro; Duval, Matías E.; Galantini, Juan A.; Bedano, José C.; Wall, Luis G.; Erijman, Leonardo

    2012-01-01

    The rise in the world demand for food poses a challenge to our ability to sustain soil fertility and sustainability. The increasing use of no-till agriculture, adopted in many areas of the world as an alternative to conventional farming, may contribute to reduce the erosion of soils and the increase in the soil carbon pool. However, the advantages of no-till agriculture are jeopardized when its use is linked to the expansion of crop monoculture. The aim of this study was to survey bacterial communities to find indicators of soil quality related to contrasting agriculture management in soils under no-till farming. Four sites in production agriculture, with different soil properties, situated across a west-east transect in the most productive region in the Argentinean pampas, were taken as the basis for replication. Working definitions of Good no-till Agricultural Practices (GAP) and Poor no-till Agricultural Practices (PAP) were adopted for two distinct scenarios in terms of crop rotation, fertilization, agrochemicals use and pest control. Non-cultivated soils nearby the agricultural sites were taken as additional control treatments. Tag-encoded pyrosequencing was used to deeply sample the 16S rRNA gene from bacteria residing in soils corresponding to the three treatments at the four locations. Although bacterial communities as a whole appeared to be structured chiefly by a marked biogeographic provincialism, the distribution of a few taxa was shaped as well by environmental conditions related to agricultural management practices. A statistically supported approach was used to define candidates for management-indicator organisms, subsequently validated using quantitative PCR. We suggest that the ratio between the normalized abundance of a selected group of bacteria within the GP1 group of the phylum Acidobacteria and the genus Rubellimicrobium of the Alphaproteobacteria may serve as a potential management-indicator to discriminate between sustainable vs. non

  20. 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 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.

  1. Bubble column apparatus for separating wax from catalyst slurry

    Science.gov (United States)

    Neathery, James K.; Davis, Burtron H.

    2004-07-13

    Novel methods and devices for production of liquid hydrocarbon products from gaseous reactants are disclosed. In one aspect, a method for separating a liquid hydrocarbon, typically a wax, from a catalyst containing slurry is provided, comprising passing the slurry through at least one downcomer extending from an overhead separation chamber and discharging into the bottom of a slurry bubble column reactor. The downcomer includes a cross-flow filtration element for separating a substantially particle-free liquid hydrocarbon for downstream processing. In another aspect, a method for promoting plug-flow movement in a recirculating slurry bubble column reactor is provided, comprising discharging the recirculating slurry into the reactor through at least one downcomer which terminates near the bottom of the reactor. Devices for accomplishing the above methods are also provided.

  2. Dimensional Precision Research of Wax Molding Rapid Prototyping based on Droplet Injection

    Science.gov (United States)

    Mingji, Huang; Geng, Wu; yan, Shan

    2017-11-01

    The traditional casting process is complex, the mold is essential products, mold quality directly affect the quality of the product. With the method of rapid prototyping 3D printing to produce mold prototype. The utility wax model has the advantages of high speed, low cost and complex structure. Using the orthogonal experiment as the main method, analysis each factors of size precision. The purpose is to obtain the optimal process parameters, to improve the dimensional accuracy of production based on droplet injection molding.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Kevin Holvoet

    2014-12-01

    Full Text Available 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.

  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. 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)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. Hijacking bacterial glycosylation for the production of glycoconjugates, from vaccines to humanised glycoproteins.

    Science.gov (United States)

    Cuccui, Jon; Wren, Brendan

    2015-03-01

    Glycosylation or the modification of a cellular component with a carbohydrate moiety has been demonstrated in all three domains of life as a basic post-translational process important in a range of biological processes. This review will focus on the latest studies attempting to exploit bacterial N-linked protein glycosylation for glycobiotechnological applications including glycoconjugate vaccine and humanised glycoprotein production. The challenges that remain for these approaches to reach full biotechnological maturity will be discussed. Oligosaccharyltransferase-dependent N-linked glycosylation can be exploited to make glycoconjugate vaccines against bacterial pathogens. Few technical limitations remain, but it is likely that the technologies developed will soon be considered a cost-effective and flexible alternative to current chemical-based methods of vaccine production. Some highlights from current glycoconjugate vaccines developed using this in-vivo production system include a vaccine against Shigella dysenteriae O1 that has passed phase 1 clinical trials, a vaccine against the tier 1 pathogen Francisella tularensis that has shown efficacy in mice and a vaccine against Staphylococcus aureus serotypes 5 and 8. Generation of humanised glycoproteins within bacteria was considered impossible due to the distinct nature of glycan modification in eukaryotes and prokaryotes. We describe the method used to overcome this conundrum to allow engineering of a eukaryotic pentasaccharide core sugar modification within Escherichia coli. This core was assembled by combining the function of the initiating transferase WecA, several Alg genes from Saccharomyces cerevisiae and the oligosaccharyltransferase function of the Campylobacter jejuni PglB. Further exploitation of a cytoplasmic N-linked glycosylation system found in Actinobacillus pleuropneumoniae where the central enzyme is known as N-linking glycosyltransferase has overcome some of the limitations demonstrated by the

  17. 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.

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

    Science.gov (United States)

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

    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.

  19. 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.

  20. Fermentative hydrogen production from hydrolyzed cellulosic feedstock prepared with a thermophilic anaerobic bacterial isolate

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Yung Chung [Department of Chemical Engineering, National Cheng Kung University, No. 1 University Road, Tainan 701 (China); Huang, Chi-Yu.; Fu, Tzu-Ning [Department of Environmental Engineering and Science, Tunghai University, Taichung 407 (China); Chen, Chun-Yen; Chang, Jo-Shu [Department of Chemical Engineering, National Cheng Kung University, No. 1 University Road, Tainan 701 (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan (China)

    2009-08-15

    Hydrogen gas was produced via dark fermentation from natural cellulosic materials and {alpha}-cellulose via a two-step process, in which the cellulosic substrates were first hydrolyzed by an isolated cellulolytic bacterium Clostridium strain TCW1, and the resulting hydrolysates were then used as substrate for fermentative H{sub 2} production. The TCW1 strain was able to hydrolyze all the cellulosic materials examined to produce reducing sugars (RS), attaining the best reducing sugar production yield of 0.65 g reducing sugar/g substrate from hydrolysis of {alpha}-cellulose. The hydrolysates of those cellulosic materials were successfully converted to H{sub 2} via dark fermentation using seven H{sub 2}-producing bacterial isolates. The bioH{sub 2} production performance was highly dependent on the type of cellulosic feedstock used, the initial reducing sugar concentration (C{sub RS,o}) (ranging from 0.7 to 4.5 mg/l), as well as the composition of sugar and soluble metabolites present in the cellulosic hydrolysates. It was found that Clostridium butyricum CGS5 displayed the highest H{sub 2}-producing efficiency with a cumulative H{sub 2} production of 270 ml/l from {alpha}-cellulose hydrolysate (C{sub RS,o} = 4.52 mg/l) and a H{sub 2} yield of 7.40 mmol/g RS (or 6.66 mmol/g substrate) from napier grass hydrolysate (C{sub RS,o} = 1.22 g/l). (author)

  1. Amylase production potentials of bacterial isolates obtained from the gut of Oryctes rhinoceros larvae

    Science.gov (United States)

    Aryati, P. C.; Pangastuti, A.; Sari, S. L. A.

    2017-04-01

    Amylase is one of the main enzymes used in industry, such as food, detergent, textile, and pharmaceutical industry. Amylase can be produced by plants, animals, and microorganisms. However, bacterial and fungal amylases have dominated application in industries. This research was aimed to determine amylolytic activity of bacteria isolated from the gut of Oryctes rhinoceros larvae. Based on clear zone formation, 9 from 11 isolates showed amylolytic activity. Isolates with the widest clear zone, i.e Bacillus subtilis GOR1, Bacillus cereus GOR3, and Bacillus pumilus GOR2, were screened for amylolytic activity based on reduction sugar production. The result showed that Bacillus subtilis GOR1 was the most potential as amylase producer, showed by the widest clear zone 5.224 cm2 and highest reduction sugar production 0.0235 mg/ml. Highest amylase specific activity (0.1447 U/mg protein) was obtained at 60°C and pH 7. Amylase activity was stable for 3 hours at 60°C with residual activity respectively was 59.7%.

  2. Using wastewater after lipid fermentation as substrate for bacterial cellulose production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Huang, Chao; Guo, Hai-Jun; Xiong, Lian; Wang, Bo; Shi, Si-Lan; Chen, Xue-Fang; Lin, Xiao-Qing; Wang, Can; Luo, Jun; Chen, Xin-De

    2016-01-20

    In this study, lipid fermentation wastewater (fermentation broth after separation with yeast biomass) with high Chemical Oxygen Demand (COD) value of 25,591 mg/L was used as substrate for bacterial cellulose (BC) production by Gluconacetobacter xylinus for the first time. After 5 days of fermentation, the highest BC yield (0.659 g/L) was obtained. Both monosaccharide and polysaccharides present in lipid fermentation wastewater could be utilized by G. xylinus simultaneously during fermentation. By this bioconversion, 30.0% of COD could be removed after 10 days of fermentation and the remaining wastewater could be used for further BC fermentation. The crystallinity of BC samples in lipid fermentation wastewater increased gradually during fermentation but overall the environment of lipid fermentation wastewater showed small influence on BC structure by comparison with that in traditional HS medium by using FE-SEM, FTIR, and XRD. By this work, the possibility of using lipid fermentation wastewater containing low value carbohydrate polymer (extracellular polysaccharides) for high value carbohydrate polymer (BC) production was proven. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. 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.

  4. 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.

  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. Improvement of bacterial cellulose production by manipulating the metabolic pathways in which ethanol and sodium citrate involved.

    Science.gov (United States)

    Li, Yuanjing; Tian, Chunjie; Tian, Hua; Zhang, Jiliang; He, Xin; Ping, Wenxiang; Lei, Hong

    2012-12-01

    Nowadays, bacterial cellulose has played more and more important role as new biological material for food industry and medical and industrial products based on its unique properties. However, it is still a difficult task to improve the production of bacterial cellulose, especially a large number of byproducts are produced in the metabolic biosynthesis processes. To improve bacterial cellulose production, ethanol and sodium citrate are added into the medium during the fermentation, and the activities of key enzymes and concentration of extracellular metabolites are measured to assess the changes of the metabolic flux of the hexose monophosphate pathway (HMP), the Embden-Meyerhof-Parnas pathway (EMP), and the tricarboxylic acid cycle (TCA). Our results indicate that ethanol functions as energy source for ATP generation at the early stage of the fermentation in the HMP pathway and the supplementation of ethanol significantly reduces glycerol generation (a major byproduct). While in the EMP pathway, sodium citrate plays a key role, and its supplementation results in the byproducts (mainly acetic acid and pyruvic acid) entering the gluconeogenesis pathway for cellulose synthesis. Furthermore, by adding ethanol and sodium citrate, the main byproduct citric acid in the TCA cycle is also reduced significantly. It is concluded that bacterial cellulose production can be improved by increasing energy metabolism and reducing the formation of metabolic byproducts through the metabolic regulations of the bypasses.

  7. 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

  8. [For an interdisciplinary museology. The particular case of anatomical waxes].

    Science.gov (United States)

    Pirson, Chloé

    2009-01-01

    Nowadays, the anatomical models in three dimensions are often showed in Museums devoted to the History of Medicine. Due to their historical importance and the major role they played as scientific education tool, they are essentials to understand the heritage of the anatomical knowledge. Historically, within all materials used to cast the body, wax has been the most frequently used, so that the ceroplastical collection has become a part of the medical education before leading to a general public pedagogy. This paper has a double purpose. In one hand, it aims to survey the formal evolution and the uses of this production, from his creation on, in the other, to study this cultural heritage within the museology issue.

  9. Bees wax and its unsaponifiables as natural preservative for butter and cottonseed oils

    Directory of Open Access Journals (Sweden)

    Farag, R. S.

    1993-06-01

    Full Text Available Simple model systems consisting of butter oil or refined cottonseed oil mixed with melted bees wax and its unsaponifiables were designated to study their hydrolytic and oxidative rancidity during storage. Whole bees wax at 0,5 and 1% levels possessed significant pro-hydrolytic activity whilst its unsaponifiables at 0,25 and 0,5% exhibited antihydrolytic effect on butter oil. The addition of whole bees wax at 0,5 and 1 % caused no effect on peroxide and thiobarbituric acid values of butter oil. However, bees wax unsaponifiables significantly reduced both peroxide and thiobarbituric acid values of stored butter oil. Bees wax unsaponifiables added to refined cottonseed oil had no effect on the acid value, whilst whole bees wax possessed significant prohydrolytic activity. The data for peroxide and thiobarbituric acid values of refined cottonseed oil demonstrated that both whole bees wax and its unsaponifiables had approximately the same antioxidant efficacy. The effectiveness of the added materials on the secondary oxidation products of refined cottonseed oil can be ranked according to its inhibition activity as follows: BHT (200 ppm > bees wax (1% > bees wax (0,5% > bees wax unsaponifiables (0,5% > bees wax unsaponifiables (0,25% > control.

    aceites de semilla de algodón Sistemas modelo simples consistentes en aceite de mantequilla o aceite de semilla de algodón refinado mezclado con cera de abeja derretida y su insaponificable fueron diseñados para estudiar su rancidez oxidativa e hidrolítica durante el almacenamiento. La cera de abeja íntegra a niveles del 0,5 y 1% tuvo una actividad pro-hidrolítica significativa, mientras que su insaponificable al 0,25 y 0,5% exhibió efecto antihidrolítico sobre el aceite de mantequilla. La adición de cera de abeja íntegra al 0,5 y 1% no causó efecto sobre el índice de peróxido y ácido tiobarbitúrico del aceite de mantequilla. Sin embargo, el insaponificable de cera de abeja redujo

  10. 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.

  11. 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.

  12. GROWTH, YIELD AND POSTHARVEST QUALITY OF WAX APPLE AS AFFECTED BY NAPHTHALENE ACETIC ACID APPLICATION

    Directory of Open Access Journals (Sweden)

    MOHAMMAD MONERUZZAMAN KHANDAKER

    2015-06-01

    Full Text Available Results of this study represent the first report of the effect of Naphthalene Acetic Acid (NAA on the pre and post harvest quality of wax apple fruit. The wax apple trees were spray treated with 0, 5, 10 and 20 mg L-1 NAA under field conditions during 2008 to 2011. The experiments were carried out in Completely Randomized Design (CRD with six replications. Leaf chlorophyll content, chlorophyll fluorescence, photosynthetic yield, net photosynthetic rate, drymatter content of leaves and total soluble solids and K+content of wax apple fruits were significantly increased after treatments with 10 mg L-1. Polygalacturonase activity significantly decreased with NAA treatments. The application of 5 mg L-1 NAA increased 27% more bud and reduced 42% less fruit drop compared to the control. In addition, higher protein and phosphate synthase activity of leaves, fruit set, fruit growth, larger fruit size and yield were recorded in NAA treated plants. In storage, treated fruits exhibited higher TSS and firmness and less weight loss, browning, titratable acidity, respiration and ethylene production than the control. It is concluded that spraying with 5 and 10 mg L-1 NAA once a week under field conditions produced better fruit growth and yield of the wax apple and maintained better fruit quality in postharvest storage.

  13. 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.

  14. Characterization of a Soil Metagenome-Derived Gene Encoding Wax Ester Synthase.

    Science.gov (United States)

    Kim, Nam Hee; Park, Ji-Hye; Chung, Eunsook; So, Hyun-Ah; Lee, Myung Hwan; Kim, Jin-Cheol; Hwang, Eul Chul; Lee, Seon-Woo

    2016-02-01

    A soil metagenome contains the genomes of all microbes included in a soil sample, including those that cannot be cultured. In this study, soil metagenome libraries were searched for microbial genes exhibiting lipolytic activity and those involved in potential lipid metabolism that could yield valuable products in microorganisms. One of the subclones derived from the original fosmid clone, pELP120, was selected for further analysis. A subclone spanning a 3.3 kb DNA fragment was found to encode for lipase/esterase and contained an additional partial open reading frame encoding a wax ester synthase (WES) motif. Consequently, both pELP120 and the full length of the gene potentially encoding WES were sequenced. To determine if the wes gene encoded a functioning WES protein that produced wax esters, gas chromatography-mass spectroscopy was conducted using ethyl acetate extract from an Escherichia coli strain that expressed the wes gene and was grown with hexadecanol. The ethyl acetate extract from this E. coli strain did indeed produce wax ester compounds of various carbon-chain lengths. DNA sequence analysis of the full-length gene revealed that the gene cluster may be derived from a member of Proteobacteria, whereas the clone does not contain any clear phylogenetic markers. These results suggest that the wes gene discovered in this study encodes a functional protein in E. coli and produces wax esters through a heterologous expression system.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Chemical language and warfare of bacterial natural products in bacteria-nematode-insect interactions.

    Science.gov (United States)

    Shi, Yi-Ming; Bode, Helge B

    2018-01-23

    Covering: up to November 2017Organismic interaction is one of the fundamental principles for survival in any ecosystem. Today, numerous examples show the interaction between microorganisms like bacteria and higher eukaryotes that can be anything between mutualistic to parasitic/pathogenic symbioses. There is also increasing evidence that microorganisms are used by higher eukaryotes not only for the supply of essential factors like vitamins but also as biological weapons to protect themselves or to kill other organisms. Excellent examples for such systems are entomopathogenic nematodes of the genera Heterorhabditis and Steinernema that live in mutualistic symbiosis with bacteria of the genera Photorhabdus and Xenorhabdus, respectively. Although these systems have been used successfully in organic farming on an industrial scale, it was only shown during the last 15 years that several different natural products (NPs) produced by the bacteria play key roles in the complex life cycle of the bacterial symbionts, the nematode host and the insect prey that is killed by and provides nutrients for the nematode-bacteria pair. Since the bacteria can switch from mutualistic to pathogenic lifestyle, interacting with two different types of higher eukaryotes, and since the full system with all players can be established in the lab, they are promising model systems to elucidate the natural function of microbial NPs. This review summarizes the current knowledge as well as open questions for NPs from Photorhabdus and Xenorhabdus and tries to assign their roles in the tritrophic relationship.

  20. 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.

  1. 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 ...

  2. 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.

  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. Comparison of different experimental techniques used for wax deposition testing

    Energy Technology Data Exchange (ETDEWEB)

    Allenson, Stephen; Johnston, Angela [Nalco Energy Services, Sugar Land, TX (United States)

    2008-07-01

    Crude oils consist of various fractions of hydrocarbons, including n-paraffins. The paraffins precipitate out of oil below the temperature called WAT (wax appearance temperature) and accumulate in flow lines and pipelines causing major transport problems. Prediction of paraffin deposition is, therefore, a key element of flow assurance programs. The purpose of this study was to develop a general and reliable approach to prediction of wax deposition based on a critical comparison of several practical lab techniques. Wax deposition study was conducted on five separate crude oils by using a varying protocols and equipment. One experimental technique was a cold stress test of wax deposition combined with ketone precipitation of waxy paraffin crystals. Another set of experiments were carried out for wax deposits formed on the surface of U-tubes and cold fingers of different designs. A comparison of the effectiveness of several wax inhibitors was conducted for these crude oils by using the selected deposition techniques. In each test method the amount of precipitated wax was recorded and compared. The deposits were characterized by melting point, qualitative and quantitative analysis of the wax components using DSC, SARA and HTGC analyses. Efficiency of paraffin inhibitors was correlated with a profile of n-paraffins distribution in the deposits. The limitations and advantages of different deposition techniques were analyzed and discussed. (author)

  6. Characterization of wax deposition by different experimental techniques - a comparison

    Energy Technology Data Exchange (ETDEWEB)

    Lindeman, Olga; Allenson, Steve

    2006-03-15

    Crude oils consist of various fractions of hydrocarbons, including n-paraffins. The paraffins precipitate out of oil below the temperature called WAT (wax appearance temperature) and accumulate in flow lines causing major transport problems. Prediction of paraffin deposition is, therefore, a key element of flow assurance programs. The purpose of this study was to develop a general and reliable approach to prediction of wax deposition based on a critical comparison of several practical lab techniques. Wax deposition study was conducted on multiple crude oils using various testing protocols and equipment. One experimental technique was a cold stress test of wax deposition combined with ketone precipitation of waxy paraffin crystals. Another set of experiments was carried out for wax deposits formed on the surface of U-tubes and cold fingers of different designs. A comparison of the effectiveness of several wax inhibitors was conducted for these crude oils by using the selected deposition techniques. In each test method the amount of precipitated wax was recorded and compared. The deposits were characterized by melting point, qualitative and quantitative analysis of the wax components using DSC, SARA and HTGC analyses. Efficiency of paraffin inhibitors was correlated with a profile of n-paraffins distribution in the deposits. The limitations and advantages of different deposition techniques were analyzed and discussed. A new test design designated ''cold tube'' is proposed. (Author) (tk)

  7. Crystal morphology of sunflower wax in soybean oil organogel

    Science.gov (United States)

    While sunflower wax has been recognized as an excellent organogelator for edible oil, the detailed morphology of sunflower wax crystals formed in an edible oil organogel has not been fully understood. In this study, polarized light microscopy, phase contrast microscopy, scanning electron microscopy ...

  8. Insights into the lifestyle of uncultured bacterial natural product factories associated with marine sponges

    Science.gov (United States)

    Lackner, Gerald; Peters, Eike Edzard; Helfrich, Eric J. N.; Piel, Jörn

    2017-01-01

    The as-yet uncultured filamentous bacteria “Candidatus Entotheonella factor” and “Candidatus Entotheonella gemina” live associated with the marine sponge Theonella swinhoei Y, the source of numerous unusual bioactive natural products. Belonging to the proposed candidate phylum “Tectomicrobia,” Candidatus Entotheonella members are only distantly related to any cultivated organism. The Ca. E. factor has been identified as the source of almost all polyketide and modified peptides families reported from the sponge host, and both Ca. Entotheonella phylotypes contain numerous additional genes for as-yet unknown metabolites. Here, we provide insights into the biology of these remarkable bacteria using genomic, (meta)proteomic, and chemical methods. The data suggest a metabolic model of Ca. Entotheonella as facultative anaerobic, organotrophic organisms with the ability to use methanol as an energy source. The symbionts appear to be auxotrophic for some vitamins, but have the potential to produce most amino acids as well as rare cofactors like coenzyme F420. The latter likely accounts for the strong autofluorescence of Ca. Entotheonella filaments. A large expansion of protein families involved in regulation and conversion of organic molecules indicates roles in host–bacterial interaction. In addition, a massive overrepresentation of members of the luciferase-like monooxygenase superfamily points toward an important role of these proteins in Ca. Entotheonella. Furthermore, we performed mass spectrometric imaging combined with fluorescence in situ hybridization to localize Ca. Entotheonella and some of the bioactive natural products in the sponge tissue. These metabolic insights into a new candidate phylum offer hints on the targeted cultivation of the chemically most prolific microorganisms known from microbial dark matter. PMID:28049838

  9. Insights into the lifestyle of uncultured bacterial natural product factories associated with marine sponges.

    Science.gov (United States)

    Lackner, Gerald; Peters, Eike Edzard; Helfrich, Eric J N; Piel, Jörn

    2017-01-17

    The as-yet uncultured filamentous bacteria "Candidatus Entotheonella factor" and "Candidatus Entotheonella gemina" live associated with the marine sponge Theonella swinhoei Y, the source of numerous unusual bioactive natural products. Belonging to the proposed candidate phylum "Tectomicrobia," Candidatus Entotheonella members are only distantly related to any cultivated organism. The Ca E. factor has been identified as the source of almost all polyketide and modified peptides families reported from the sponge host, and both Ca Entotheonella phylotypes contain numerous additional genes for as-yet unknown metabolites. Here, we provide insights into the biology of these remarkable bacteria using genomic, (meta)proteomic, and chemical methods. The data suggest a metabolic model of Ca Entotheonella as facultative anaerobic, organotrophic organisms with the ability to use methanol as an energy source. The symbionts appear to be auxotrophic for some vitamins, but have the potential to produce most amino acids as well as rare cofactors like coenzyme F 420 The latter likely accounts for the strong autofluorescence of Ca Entotheonella filaments. A large expansion of protein families involved in regulation and conversion of organic molecules indicates roles in host-bacterial interaction. In addition, a massive overrepresentation of members of the luciferase-like monooxygenase superfamily points toward an important role of these proteins in Ca Entotheonella. Furthermore, we performed mass spectrometric imaging combined with fluorescence in situ hybridization to localize Ca Entotheonella and some of the bioactive natural products in the sponge tissue. These metabolic insights into a new candidate phylum offer hints on the targeted cultivation of the chemically most prolific microorganisms known from microbial dark matter.

  10. Production rates of bacterial tetraether lipids and fatty acids in peatland under varying oxygen concentrations

    Science.gov (United States)

    Huguet, Arnaud; Meador, Travis B.; Laggoun-Défarge, Fatima; Könneke, Martin; Wu, Weichao; Derenne, Sylvie; Hinrichs, Kai-Uwe

    2017-04-01

    Interpretations of the abundance and distribution of branched glycerol dialkyl glycerol tetraether (brGDGT) lipids have been increasingly applied to infer changes in paleoenvironment and to estimate terrigenous organic matter inputs into estuarine and marine sediments. However, only preliminary information is known regarding the ecology and physiology of the source organisms of these biomarkers. We assessed the production rates of brGDGTs under different redox conditions in peat, where these lipids are found in high concentrations, particularly at greater depths below the fluctuating water table. The incorporation of hydrogen relative to carbon into lipids observed in our dual stable isotope probing assay indicates that brGDGTs were produced by heterotrophic bacteria. Unexpectedly, incubations with stable isotope tracers of the surface horizon (5-20 cm) initiated under oxic conditions before turning suboxic and eventually anoxic exhibited up to one order of magnitude higher rates of brGDGT production (16-87 ng cm-3 y-1) relative to the deeper, anoxic zone (20-35 cm; ca. 7 ng cm-3 y-1), and anoxic incubations of the surface horizon (Turnover times of brGDGTs in the surface horizon ranged between 8 and 41 years in the incubations initiated under oxic conditions, in contrast to 123-742 years in anoxic incubations. As brGDGTs were actively produced during both anoxic incubations and those exposed to oxygen, we conclude that their source organisms are likely facultative aerobic heterotrophs that are particularly active in the peat acrotelm. Production rates of bacterial fatty acids (ca. 2 μg cm-3 y-1) were roughly two orders of magnitude higher than those of brGDGTs, suggesting that brGDGT producers are a minor constituent of the microbial community or that brGDGTs are a small component of the microbial cell membrane in comparison to fatty acids, despite the typically high brGDGT concentrations observed in peat. Multivariate analysis identified two branched fatty acids

  11. Modeling Klebsiella pneumoniae Pathogenesis by Infection of the Wax Moth Galleria mellonella

    Science.gov (United States)

    Insua, José Luis; Llobet, Enrique; Moranta, David; Pérez-Gutiérrez, Camino; Tomás, Anna; Garmendia, Junkal

    2013-01-01

    The implementation of infection models that approximate human disease is essential for understanding pathogenesis at the molecular level and for testing new therapies before they are entered into clinical stages. Insects are increasingly being used as surrogate hosts because they share, with mammals, essential aspects of the innate immune response to infections. We examined whether the larva of the wax moth Galleria mellonella could be used as a host model to conceptually approximate Klebsiella pneumoniae-triggered pneumonia. We report that the G. mellonella model is capable of distinguishing between pathogenic and nonpathogenic Klebsiella strains. Moreover, K. pneumoniae infection of G. mellonella models some of the known features of Klebsiella-induced pneumonia, i.e., cell death associated with bacterial replication, avoidance of phagocytosis by phagocytes, and the attenuation of host defense responses, chiefly the production of antimicrobial factors. Similar to the case for the mouse pneumonia model, activation of innate responses improved G. mellonella survival against subsequent Klebsiella challenge. Virulence factors necessary in the mouse pneumonia model were also implicated in the Galleria model. We found that mutants lacking capsule polysaccharide, lipid A decorations, or the outer membrane proteins OmpA and OmpK36 were attenuated in Galleria. All mutants activated G. mellonella defensive responses. The Galleria model also allowed us to monitor Klebsiella gene expression. The expression levels of cps and the loci implicated in lipid A remodeling peaked during the first hours postinfection, in a PhoPQ- and PmrAB-governed process. Taken together, these results support the utility of G. mellonella as a surrogate host for assessing infections with K. pneumoniae. PMID:23836821

  12. Indoleacetic acid production and plant growth promoting potential of bacterial endophytes isolated from rice (Oryza sativa L.) seeds.

    Science.gov (United States)

    Shahzad, Raheem; Waqas, Muhammad; Khan, Abdul Latif; Al-Hosni, Khadija; Kang, Sang-Mo; Seo, Chang-Woo; Lee, In-Jung

    2017-06-01

    Bacterial endophytes from the phyllosphere and rhizosphere have been used to produce bioactive metabolites and to promote plant growth. However, little is known about the endophytes residing in seeds. This study aimed to isolate and identify seed-borne bacterial endophytes from rice and elucidate their potential for phytohormone production and growth enhancement. The isolated endophytes included Micrococcus yunnanensis RWL-2, Micrococcus luteus RWL-3, Enterobacter soli RWL-4, Leclercia adecarboxylata RWL-5, Pantoea dispersa RWL-6, and Staphylococcus epidermidis RWL-7, which were identified using 16S rRNA sequencing and phylogenetic analysis. These strains were analyzed for indoleacetic acid (IAA) production by using GC-MS and IAA was found in the range of 11.50 ± 0.77 μg ml -1 to 38.80 ± 1.35 μg ml -1 . We also assessed the strains for plant growth promoting potential because these isolates were able to produce IAA in pure culture. Most of the growth attributes of rice plants (shoot and root length, fresh and dry biomass, and chlorophyll content) were significantly increased by bacterial endophytes compared to the controls. These results show that IAA producing bacterial endophytes can improve hostplant growth traits and can be used as bio-fertilizers.

  13. 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.

  14. RDR1 and SGS3, Components of RNA-Mediated Gene Silencing, Are Required for the Regulation of Cuticular Wax Biosynthesis in Developing Inflorescence Stems of Arabidopsis1[W][OA

    Science.gov (United States)

    Lam, Patricia; Zhao, Lifang; McFarlane, Heather E.; Aiga, Mytyl; Lam, Vivian; Hooker, Tanya S.; Kunst, Ljerka

    2012-01-01

    The cuticle is a protective layer that coats the primary aerial surfaces of land plants and mediates plant interactions with the environment. It is synthesized by epidermal cells and is composed of a cutin polyester matrix that is embedded and covered with cuticular waxes. Recently, we have discovered a novel regulatory mechanism of cuticular wax biosynthesis that involves the ECERIFERUM7 (CER7) ribonuclease, a core subunit of the exosome. We hypothesized that at the onset of wax production, the CER7 ribonuclease degrades an mRNA specifying a repressor of CER3, a wax biosynthetic gene whose protein product is required for wax formation via the decarbonylation pathway. In the absence of this repressor, CER3 is expressed, leading to wax production. To identify the putative repressor of CER3 and to unravel the mechanism of CER7-mediated regulation of wax production, we performed a screen for suppressors of the cer7 mutant. Our screen resulted in the isolation of components of the RNA-silencing machinery, RNA-DEPENDENT RNA POLYMERASE1 and SUPPRESSOR OF GENE SILENCING3, implicating RNA silencing in the control of cuticular wax deposition during inflorescence stem development in Arabidopsis (Arabidopsis thaliana). PMID:22689894

  15. 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

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. 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

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

    Science.gov (United States)

    Costa, Andrea F. S.; Almeida, Fabíola C. G.; Vinhas, Glória M.; Sarubbo, Leonie A.

    2017-01-01

    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. The values

  2. Effect of Single Bacterial Starter Culture on Odour Reduction During Controlled Fermentation of Cassava Tubers for Foofoo Production

    OpenAIRE

    Henshaw, E. E.; Ikpoh, I. S

    2010-01-01

    Effects of single bacterial starter culture on odour reduction during controlled fermentation of cassava tubers for foofoo production were investigated. Pure cultures were used to ferment cassava tubers in water for 96 h. The cultures used include Bacillus subtilis, Klebsiela sp., Lactobacillus plantarum and Leuconostoc mesenteroides. L. plantarum exhibited the highest acid producing ability, decreasing the pH of the Cassava tubers from 6.2 to 3.68 with a corresponding increase in total titra...

  3. 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.

  4. Spatially Resolved Characterization of Biogenic Manganese Oxide Production within a Bacterial Biofilm

    Science.gov (United States)

    Toner, Brandy; Fakra, Sirine; Villalobos, Mario; Warwick, Tony; Sposito, Garrison

    2005-01-01

    Pseudomonas putida strain MnB1, a biofilm-forming bacterial culture, was used as a model for the study of bacterial Mn oxidation in freshwater and soil environments. The oxidation of aqueous Mn+2 [Mn+2(aq)] by P. putida was characterized by spatially and temporally resolving the oxidation state of Mn in the presence of a bacterial biofilm, using scanning transmission X-ray microscopy (STXM) combined with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the Mn L2,3 absorption edges. Subsamples were collected from growth flasks containing 0.1 and 1 mM total Mn at 16, 24, 36, and 48 h after inoculation. Immediately after collection, the unprocessed hydrated subsamples were imaged at a 40-nm resolution. Manganese NEXAFS spectra were extracted from X-ray energy sequences of STXM images (stacks) and fit with linear combinations of well-characterized reference spectra to obtain quantitative relative abundances of Mn(II), Mn(III), and Mn(IV). Careful consideration was given to uncertainty in the normalization of the reference spectra, choice of reference compounds, and chemical changes due to radiation damage. The STXM results confirm that Mn+2(aq) was removed from solution by P. putida and was concentrated as Mn(III) and Mn(IV) immediately adjacent to the bacterial cells. The Mn precipitates were completely enveloped by bacterial biofilm material. The distribution of Mn oxidation states was spatially heterogeneous within and between the clusters of bacterial cells. Scanning transmission X-ray microscopy is a promising tool for advancing the study of hydrated interfaces between minerals and bacteria, particularly in cases where the structure of bacterial biofilms needs to be maintained. PMID:15746332

  5. High-throughput assessment of bacterial ecology in hog, cow and ovine casings used in sausages production.

    Science.gov (United States)

    Rebecchi, Annalisa; Pisacane, Vincenza; Miragoli, Francesco; Polka, Justyna; Falasconi, Irene; Morelli, Lorenzo; Puglisi, Edoardo

    2015-11-06

    Natural casings derived from different intestine portions have been used for centuries in the production of fresh and dry-fermented sausages. Here we analysed by means of culture-dependent methods and Illumina high-throughput sequencing of 16S rRNA amplicons the bacterial ecology of hog, cow and ovine casings at different stages of their preparation for sausages production. Several strains of Staphylococcus, Lactobacillus, Bifidobacterium, Vagococcus and Clostridium were counted, isolated and characterised at phylogenetic level. High-throughput sequencing analyses revealed a high bacterial diversity, which differed strongly between casings of different animal species. The technological processes involved in the preparation for casing had also a strong impact on the casings bacterial ecology, with a significant reduction of undesired microorganisms, and an increase in the proportion of lactobacilli and staphylococci. Natural casings were demonstrated to be complex ecological environments, whose role as microbiological inoculants in the production of sausages should not be underestimated. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Surfactant-free dispersion of Montan wax and Montan resin; Tensidfreie Dispersion von Montanwachs und Montanharz

    Energy Technology Data Exchange (ETDEWEB)

    Wollenberg, R.; Naundorf, W. [Technische Univ. Bergakademie Freiberg (Germany); Abraham, J. [ROMONTA GmbH, Amsdorf (Germany)

    2000-04-01

    The purpose of this research project was the surfactant-free dispersion of lignite wax products in water in order to avoid the use of expensive surfactants that are employed in conventional process methods and some of which are harmful to the environment, and in some cases also impair the useful properties of the dispersed system. Based on experimental investigations, the wet grinding process at low temperatures below the melting point of the lignite wax products was developed. The products are surfactant-free watery dispersions of lignite wax or lignite resin. The new dispersed systems can be produced at low cost and have very good properties of use. (orig.) [German] Das Ziel der Forschung war die tensidfreie Dispergierung von Montanwachsprodukten in Wasser, um die in herkoemmlicher Verfahrensweise einzusetzenden teuren und teilweise umweltschaedlichen Tenside einzusparen, die in einigen Faellen auch die Anwendungseigenschaften des dispersen Systems beeintraechtigen. Auf der Basis von experimentellen Untersuchungen wurde das Nassmahlverfahren bei tiefen Temperaturen unter dem Schmelzpunkt der Montanwachsprodukte entwickelt. Die Produkte sind tensidfreie waessrige Dispersionen aus Montanwachs oder Montanharz. Die neuen dispersen Systeme sind kostenguenstig herstellbar und haben sehr gute Anwendungseigenschaften. (orig.)

  7. 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

  8. Ultraviolet-induced changes in cuticular waxes of American cockroaches, Periplaneta americana (L.)(Dictyoptera: Blattaria: Blattidae)

    International Nuclear Information System (INIS)

    Gingrich, J.B.

    1975-01-01

    Dorsal cuticles of fully tanned American cockroaches irradiated with sublethal ultraviolet radiation (254 nm) were compared with nonirradiated cockroaches for wax composition. Of the six waxes compared, four (C 18 , C 19 , C 25 , and 3-methylpentacosane) showed increases of more than 50% in UV-irradiated cockroaches while C 17 and C 27 (heptacosa-6,9-diene) showed smaller increases of 27 and 11%, respectively. Traces of C 20 , C 22 , C 23 , and C 24 hydrocarbons were indicated but these were not compared since their identification has not been substantiated by other authors. The possible explanations of cellular damage vs. stimulated production are discussed. (author)

  9. Rapid Prototyping of wax foundry models in an incremental process

    Directory of Open Access Journals (Sweden)

    B. Kozik

    2011-04-01

    Full Text Available The paper presents an analysis incremental methods of creating wax founding models. There are two methods of Rapid Prototypingof wax models in an incremental process which are more and more often used in industrial practice and in scientific research.Applying Rapid Prototyping methods in the process of making casts allows for acceleration of work on preparing prototypes. It isespecially important in case of element having complicated shapes. The time of making a wax model depending on the size and the appliedRP method may vary from several to a few dozen hours.

  10. Transesterification of Jojoba Oil-Wax Using Microwave Technique

    OpenAIRE

    Labiba I. Hussein; Maher Z. Elsabee; Eid A. Ismail; Hala F. Naguib; Hilda A. Aziz; Moataz A. Elsawy

    2014-01-01

    Jojoba oil-wax is extracted from the seeds of the jojoba (Simmondsia chinensis Link Schneider), a perennial shrub that grows in semi desert areas in Egypt and in some parts of the world. The main uses of jojoba oil-wax are in the cosmetics and pharmaceutical industry, but new uses could arise related to the search of new energetic crops. This paper summarizes a process to convert the jojoba oil-wax to biodiesel by transesterification with ethanol and a series of aliphatic alcohols using a mor...

  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. 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

  13. 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

  14. Quantitative trait loci controlling amounts and types of epicuticular waxes in onion

    Science.gov (United States)

    Natural variation exists in onion (Allium cepa L.) for amounts and types of epicuticular waxes on leaves. Wild-type waxy onion possesses copious amounts of these waxes, while the foliage of semi-glossy and glossy phenotypes accumulate significantly less wax. Reduced amounts of epicuticular waxes hav...

  15. 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.

  16. 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.

  17. The Effect of Prebiotic and Probiotic Feed Supplementation on the Wax Glands of Worker Bees (Apis Mellifera

    Directory of Open Access Journals (Sweden)

    Silvia Pătruică

    2012-10-01

    Full Text Available This paper presents the effects of acidifying substances (lactic acid or acetic acid, Enterobiotics products(Lactobacillus acidophilus LA-14 and Bifidobacterium lactis BI-04 and Enterolactis Plus (Lactobacillus casei onthe wax glands of worker bees. The research was conducted in Timis County, Romania, between March 25 and April20, 2011, on 110 colonies of bees (Apis mellifera carpatica, allocated to 11 experimental treatment groups. Coloniesin the experimental groups were given three weekly feeds of sugar syrup supplemented with acidifying substances(lactic acid or cider vinegar and/or probiotic products (Enterobiotics or Enterolactis Plus. Three weeks after theadministration of the experimental diets, 10 worker bees from each treatment group were sampled for histologicalexamination of their wax glands. Gland development was shown to be influenced by administration of prebioticand/or probiotic supplements. Wax gland cell sizes ranged from 25.1 microns for the control group to between 27.8and 31.8 microns in the group fed with acidifying substances and between 26.9 and 29.2 microns in bees fed withprobiotic products. Bees supplemented with both lactic acid and probiotic product (group LE9 and LE10 showedmean wax cell sizes of 31.8 microns.

  18. Efficient and selective degradation of polyethylenes into liquid fuels and waxes under mild conditions

    Science.gov (United States)

    Jia, Xiangqing; Qin, Chuan; Friedberger, Tobias; Guan, Zhibin; Huang, Zheng

    2016-01-01

    Polyethylene (PE) is the largest-volume synthetic polymer, and its chemical inertness makes its degradation by low-energy processes a challenging problem. We report a tandem catalytic cross alkane metathesis method for highly efficient degradation of polyethylenes under mild conditions. With the use of widely available, low-value, short alkanes (for example, petroleum ethers) as cross metathesis partners, different types of polyethylenes with various molecular weights undergo complete conversion into useful liquid fuels and waxes. This method shows excellent selectivity for linear alkane formation, and the degradation product distribution (liquid fuels versus waxes) can be controlled by the catalyst structure and reaction time. In addition, the catalysts are compatible with various polyolefin additives; therefore, common plastic wastes, such as postconsumer polyethylene bottles, bags, and films could be converted into valuable chemical feedstocks without any pretreatment. PMID:27386559

  19. 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)

  20. 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.

  1. Bacterial production, primary production, phytoplankton, zooplankton, biological analysis of fish, and massive fish length data from the EVRIKA and other platforms in the Antarctic from 23 February 1980 to 09 December 1988 (NODC Accession 9600039)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bacterial production, primary production, phytoplankton, zooplankton, biological analysis of fish, and massive fish length data were collected from the EVRIKA and...

  2. Cucumis sativus L. WAX2 Plays a Pivotal Role in Wax Biosynthesis, Influencing Pollen Fertility and Plant Biotic and Abiotic Stress Responses.

    Science.gov (United States)

    Wang, Wenjiao; Liu, Xingwang; Gai, Xinshuang; Ren, Jiaojiao; Liu, Xiaofeng; Cai, Yanling; Wang, Qian; Ren, Huazhong

    2015-07-01

    Cuticular waxes play an important part in protecting plant aerial organs from biotic and abiotic stresses. In previous studies, the biosynthetic pathway of cuticular waxes and relative functional genes has been researched and understood; however, little is known in cucumber (Cucumis sativus L.). In this study, we cloned and characterized an AtWAX2 homolog, CsWAX2, in cucumber and found that it is highly expressed in the epidermis, where waxes are synthesized, while subcellular localization showed that CsWAX2 protein is localized to the endoplasmic reticulum (ER). The transcriptional expression of CsWAX2 was found to be induced by low temperature, drought, salt stress and ABA, while the ectopic expression of CsWAX2 in an Arabidopsis wax2 mutant could partially complement the glossy stem phenotype. Abnormal expression of CsWAX2 in transgenic cucumbers specifically affected both very long chain (VLC) alkanes and cutin biosynthesis. Furthermore, transgenic cucumber plants of CsWAX2 showed significant changes in pollen viability and fruit resistance to water loss and pathogens compared with the wild type. Collectively, these results indicated that CsWAX2 plays a pivotal role in wax biosynthesis, influencing pollen fertility and the plant's response to biotic and abiotic stresses. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. 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.

  4. Radiation or waxing effect on shelf life of guava fruit

    International Nuclear Information System (INIS)

    Wahid, M.; Sattar, A.; Khan, M.N.; Hussain, B.

    1993-01-01

    Red and white guavas were treated with wax emulsion or irradiation (0.25-2.0 kGy) and kept for 12 days at room temperature. Rot attack occurred after 3 days which increased significantly during further storage for all guavas. In the waxed guavas rottage, weight loss and vitamin loss were significantly less than controls and irradiated ones. Sensory scores decreased with storage time and they were 3.7-4.5, 2.1-3.9 and 2.3-2.7 in waxed. irradiated and untreated controls respectively, after 12 days storage. Waxing was found to increase the shelf life of guavas for 3-4 d while irradiation exhibited no beneficial effects

  5. Bacterial Production and Contamination Mineralization in Sediments of the Ala Wai Canal, Oahu, Hawaii

    Science.gov (United States)

    2009-09-29

    sediments near the middle of Pearl Harbor (Montgomery and Osburn 2004) but lower than those taken near creosote -treated pilings (Boyd et al. 2008...marine sediments. Bioremediation 12(2):1-13. Montgomery, M.T., S.E. Walker, T.J. Boyd, L.J. Hamdan, and C.L. Osburn. 2008. Bacterial degradation

  6. 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

  7. 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.

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

    Science.gov (United States)

    1994-10-01

    Association of Pulp and Paper Industry TEA Triethanolamine TNT 2,4,6-Trinitrotoluene TNTO A combination of TNT and NTO TPP Triphenylphosphate USP United...Candelilla wax is used in cosmetics. It is extracted from shrubs in Mexico and to a lesser extent in the Big Bend area in Texas. The Mexican government...from the same mine in East Germany. China , USSR and Czech Republic are also known to have deposits of montan waxes. Table 7 shows the estimated

  9. Inhibition of osteoporosis in rats fed with sugar cane wax.

    Science.gov (United States)

    Tamaki, Hajime; Man, Sun Li; Ohta, Yutaka; Katsuyama, Naofumi; Chinen, Isao

    2003-02-01

    Rats fed on a restricted, semi-purified diet containing a 50%-reduced level of carbohydrate and oil, but normal levels of protein, minerals and vitamins, exhibited osteoporosis. However, rats fed on this restricted diet, but containing sugar cane wax, did not exhibit this bone disease. Sugar cane wax, containing a long-chain carbohydrate with an OH radical, prevented the development of osteoporosis via a non-estrogenic mechanism.

  10. 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.

  11. Bacterial community in naturally fermented milk products of Arunachal Pradesh and Sikkim of India analysed by high-throughput amplicon sequencing

    OpenAIRE

    Shangpliang, H. Nakibapher Jones; Rai, Ranjita; Keisam, Santosh; Jeyaram, Kumaraswamy; Tamang, Jyoti Prakash

    2018-01-01

    Naturally fermented milk (NFM) products are popular ethnic fermented foods in Arunachal Pradesh and Sikkim states of India. The present study is the first to have documented the bacterial community in 54 samples of NFM products viz. chhurpi, churkam, dahi and gheu/mar by high-throughput Illumina amplicon sequencing. Metagenomic investigation showed that Firmicutes (Streptococcaceae, Lactobacillaceae) and Proteobacteria (Acetobacteraceae) were the two predominant members of the bacterial commu...

  12. 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.

  13. 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.

  14. 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...

  15. 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

  16. 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.)

  17. 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.

  18. 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.

  19. Extraction and characterization of wax from sugarcane bagasse and the enzymatic hydrolysis of dewaxed sugarcane bagasse.

    Science.gov (United States)

    Qi, Gaoxiang; Peng, Fen; Xiong, Lian; Lin, Xiaoqing; Huang, Chao; Li, Hailong; Chen, Xuefang; Chen, Xinde

    2017-03-16

    Extraction of high-value products from agricultural wastes is an important component for sustainable bioeconomy development. In this study, wax extraction from sugarcane bagasse was performed and the beneficial effect of dewaxing pretreatment on the enzymatic hydrolysis was investigated. About 1.2% (w/w) of crude sugarcane wax was obtained from the sugarcane bagasse using the mixture of petroleum ether and ethanol (mass ratio of 1:1) as the extraction agent. Results of Fourier-transform infrared characterization and gas chromatography-mass spectrometry qualitative analysis showed that the crude sugarcane wax consisted of fatty fractions (fatty acids, fatty aldehydes, hydrocarbons, and esters) and small amount of lignin derivatives. In addition, the effect of dewaxing pretreatment on the enzymatic hydrolysis of sugarcane bagasse was also investigated. The digestibilities of cellulose and xylan in dewaxed sugarcane bagasse were 18.7 and 10.3%, respectively, compared with those of 13.1 and 8.9% obtained from native sugarcane bagasse. The dewaxed sugarcane bagasse became more accessible to enzyme due to the disruption of the outermost layer of the waxy materials.

  20. Physical Properties, Volatiles Compositions and Sensory Descriptions of the Aromatized Hazelnut Oil-Wax Organogels.

    Science.gov (United States)

    Yılmaz, Emin; Öğütcü, Mustafa; Yüceer, Yonca Karagül

    2015-09-01

    The purpose of this study was to determine the physicochemical, thermal and sensorial features of vitamin enriched and aromatized hazelnut oil-beeswax and sunflower wax organogels. Another objective was to monitor the influence of storage on textural and oxidative stability and volatile composition of the organogels. The results show that organogels with beeswax had lower levels of solid fat content, melting point and firmness than sunflower wax counterparts. The microphotographs revealed that beeswax organogels had spherical crystals while sunflower wax organogels continued need-like crystals, but both organogels continued crystallized β' polymorph. All organogels maintained their oxidative stability during storage. Quantitative descriptive analysis results were consistent with these findings that the organogel structure and properties were similar to breakfast margarine. The main volatile components of the organogels with added strawberry aroma were ethyl acetate, ethyl butanoate, ethyl-2-methyl butanoate, D-limonene, ethyl caproate; banana-aroma were isoamyl acetate, isoamyl valerianate, ethyl acetate; and butter-aroma were 2,3-butanedione, 3-hydroxy-2-butanone. These volatile components were not only detected in the fresh samples but also at the end of the storage period. Sensory definition terms were matched with the sensory descriptors of the detected volatiles. In conclusion, the new organogels were shown to be suitable for food product applications. © 2015 Institute of Food Technologists®

  1. The resistance of surfaces treated with oils and waxes to the action of dry heat

    Directory of Open Access Journals (Sweden)

    Jaić Milan

    2009-01-01

    Full Text Available Surface treatment of wood can be done with different coatings, and the choice of the appropriate system of processing depends on several factors, such as technological, aesthetic, economic and ecological. Raising awareness of the need to preserve the living and working environment has had a crucial impact on the increase in the use of natural materials for surface treatment of wood - oil and wax. The application of oils and waxes allows surface treated wood to keep the natural look, while protecting it from different influences, which can cause degradation and deterioration of the final product. The paper presents the results of testing the resistance of beech surface (Fagus silvatica L. processed with linseed oil and beeswax to the action of dry heat. In order to compare the quality of surface treated with oil and/or wax, beech wood treated with 2K-polyurethane coating is taken as a reference of surface treatment of wood. Surfaces treated with beeswax are less resistant to dry heat than those treated with linseed oil, and both showed significantly less resistance than surface treated with 2K-polyurethane coating.

  2. 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.

  3. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    , 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...

  4. Longitudinal changes in protistan bacterivory and bacterial production in two canyon-shaped reservoirs of different trophic status

    Czech Academy of Sciences Publication Activity Database

    Jezbera, Jan; Nedoma, Jiří; Šimek, Karel

    2003-01-01

    Roč. 504, - (2003), s. 115-130 ISSN 0018-8158. [Reservoir Limnology and Water Quality /4./. České Budějovice, 12.08.2002-16.08.2002] R&D Projects: GA ČR GA206/99/0028; GA ČR GA206/02/0003 Institutional research plan: CEZ:AV0Z6017912 Keywords : canyon-shaped reservoirs * bacterial production * protistan bacterivory Subject RIV: EE - Microbiology, Virology Impact factor: 0.720, year: 2003

  5. 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.

  6. Use of Response Surface Methodology to Optimize Culture Conditions for Hydrogen Production by an Anaerobic Bacterial Strain from Soluble Starch

    Science.gov (United States)

    Kieu, Hoa Thi Quynh; Nguyen, Yen Thi; Dang, Yen Thi; Nguyen, Binh Thanh

    2016-05-01

    Biohydrogen is a clean source of energy that produces no harmful byproducts during combustion, being a potential sustainable energy carrier for the future. Therefore, biohydrogen produced by anaerobic bacteria via dark fermentation has attracted attention worldwide as a renewable energy source. However, the hydrogen production capability of these bacteria depends on major factors such as substrate, iron-containing hydrogenase, reduction agent, pH, and temperature. In this study, the response surface methodology (RSM) with central composite design (CCD) was employed to improve the hydrogen production by an anaerobic bacterial strain isolated from animal waste in Phu Linh, Soc Son, Vietnam (PL strain). The hydrogen production process was investigated as a function of three critical factors: soluble starch concentration (8 g L-1 to 12 g L-1), ferrous iron concentration (100 mg L-1 to 200 mg L-1), and l-cysteine concentration (300 mg L-1 to 500 mg L-1). RSM analysis showed that all three factors significantly influenced hydrogen production. Among them, the ferrous iron concentration presented the greatest influence. The optimum hydrogen concentration of 1030 mL L-1 medium was obtained with 10 g L-1 soluble starch, 150 mg L-1 ferrous iron, and 400 mg L-1 l-cysteine after 48 h of anaerobic fermentation. The hydrogen concentration produced by the PL strain was doubled after using RSM. The obtained results indicate that RSM with CCD can be used as a technique to optimize culture conditions for enhancement of hydrogen production by the selected anaerobic bacterial strain. Hydrogen production from low-cost organic substrates such as soluble starch using anaerobic fermentation methods may be one of the most promising approaches.

  7. Evaluating the possibility of using acetone-butanol-ethanol (ABE) fermentation wastewater for bacterial cellulose production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Huang, C; Yang, X-Y; Xiong, L; Guo, H-J; Luo, J; Wang, B; Zhang, H-R; Lin, X-Q; Chen, X-D

    2015-05-01

    To reduce the cost of bacterial cellulose (BC) production, the possibility of using acetone-butanol-ethanol (ABE) fermentation wastewater with high COD value (18 050 mg l(-1) ) for BC production by Gluconacetobacter xylinus was evaluated. After 7 days of fermentation, the highest BC yield (1·34 g l(-1) ) was obtained. The carbon sources including sugars (glucose and xylose), organic acids (acetic acid and butyric acid) and alcohol compounds (ethanol and butanol) were utilized by G. xylinus simultaneously during fermentation. Although the COD decrease ratio (about 14·7%) was low, the highest BC yield on COD consumption (56·2%, g g(-1) ) was relatively high and the remaining wastewater could be used for further BC fermentation. Besides, the environment of ABE fermentation wastewater showed small influence on the BC structure by comparison with the BC products obtained in traditional HS medium using field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Overall, ABE fermentation wastewater is one promising substrate for BC production. The possibility of using acetone-butanol-ethanol (ABE) fermentation wastewater for bacterial cellulose (BC) production by Gluconacetobacter xylinus was evaluated in this study. This is the first time that ABE fermentation wastewater was used as substrate for BC fermentation. The results provide detail information of metabolism of G. xylinus in ABE fermentation wastewater and the influence of wastewater environment on the structure of BC samples. Overall, this bioconversion could reduce the cost of BC production greatly. © 2015 The Society for Applied Microbiology.

  8. 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 prot...... to produce proteins with humanlike glycan structures setting the stage for production of pharmaceutical proteins in bacteria, yeasts and algae....

  9. Leaf waxes and thrips resistance in onion

    Science.gov (United States)

    Onion thrips is an important insect pest of onion that damages leaves and bulbs, reduces yields, and transmits important diseases such as iris yellow spot virus and bacterial rots. Growers would benefit from onions resistant to thrips in order to reduce insecticide applications and provide more sust...

  10. 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.

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

    Science.gov (United States)

    Anyaogu, Diana Chinyere; Mortensen, Uffe Hasbro

    2015-12-01

    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 proteins, they are frequently N-glycosylated. This hampers production in microbes as these hosts glycosylate proteins differently. The resulting products may therefore be immunogenic, unstable and show reduced efficacy. Recently, successful glycoengineering of microbes has demonstrated that it is possible to produce proteins with humanlike glycan structures setting the stage for production of pharmaceutical proteins in bacteria, yeasts and algae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. 9 CFR 113.100 - General requirements for inactivated bacterial products.

    Science.gov (United States)

    2010-01-01

    ... from each serial shall be tested for safety in young adult mice in accordance with the test provided in... in poultry as defined in the specific Standard Requirement or Outline of Production for the product...

  13. Amended final report on the safety assessment of Oryza Sativa (rice) Bran Oil, Oryza Sativa (rice) Germ Oil, Rice Bran Acid,Oryza Sativa (rice) Bran Wax, Hydrogenated Rice Bran Wax, Oryza Sativa (rice)Bran Extract, Oryza Sativa (rice) Extract, Oryza Sativa (rice) Germ Powder, Oryza Sativa (rice) Starch, Oryza Sativa (rice) Bran, Hydrolyzed Rice Bran Extract, Hydrolyzed Rice Bran Protein, Hydrolyzed Rice Extract, and Hydrolyzed Rice Protein.

    Science.gov (United States)

    2006-01-01

    This report addresses the safety of cosmetic ingredients derived from rice, Oryza sativa. Oils, Fatty Acids, and Waxes: Rice Bran Oil functions in cosmetics as a conditioning agent--occlusive in 39 formulations across a wide range of product types. Rice Germ Oil is a skin-conditioning agent--occlusive in six formulations in only four product categories. Rice Bran Acid is described as a surfactant-cleansing agent, but was not in current use. Rice Bran Wax is a skin-conditioning agent--occlusive in eight formulations in five product categories. Industry did not directly report any use of Rice Bran Wax. Hydrogenated Rice Bran Wax is a binder, skin-conditioning agent--occlusive, and viscosity-increasing agent--nonaqueous in 11 formulations in six product categories. Rice Bran Oil had an oral LD50 of > 5 g/kg in white rats and Rice Wax had an oral LD50 of > 24 g/kg in male mice. A three-generation oral dosing study reported no toxic or teratologic effects in albino rats fed 10% Rice Bran Oil compared to a control group fed Peanut Oil. Undiluted Rice Bran Oil, Rice Germ Oil, and Hydrogenated Rice Bran Wax were not irritants in animal skin tests. Rice Bran Oil was not a sensitizer. Rice Bran Oil, Rice Germ Oil, Rice Wax, and Hydrogenated Rice Bran Wax were negative in ocular toxicity assays. A mixture of Rice Bran Oil and Rice Germ Oil had a ultraviolet (UV) absorption maximum at 315 nm, but was not phototoxic in a dermal exposure assay. Rice Bran Oil was negative in an Ames assay, and a component, gamma-oryzanol, was negative in bacterial and mammalian mutagenicity assays. Rice oils, fatty acids, and waxes were, at most, mildly irritating in clinical studies. Extracts: Rice Bran Extract is used in six formulations in four product categories. Rice Extract is a hair-conditioning agent, but was not in current use. Hydrolyzed Rice Extract is used in four formulations and current concentration of use data were provided for other uses. Hydrolyzed Rice Bran Extract, described

  14. Nitrogen control of bacterial signal production in Rhizobium meliloti-alfalfa symbiosis.

    Science.gov (United States)

    Dusha, Ilona

    2002-09-01

    Under nitrogen-depleted conditions nitrogen-fixing soil bacteria of the family Rhizobiaceae are able to induce symbiotic nodules on the roots of leguminous plants where bacteroids convert atmospheric nitrogen to ammonia. The presence of exogenous nitrogen source inhibits the development and the functioning of bacterium-plant symbiosis. Earlier experiments demonstrated that nitrate inhibited all stages of symbiotic interaction, affecting primarily the host functions. The investigation of the possible involvement of the microsymbiont in nitrogen regulation showed that two signalling steps were controlled by ammonium. The synthesis of the first bacterial signal, the Nod factor was repressed by ammonium. The nitrogen signal is conveyed to nodulation (nod) genes by the general nitrogen regulatory (ntr) system and by the nodD3-syrM self-amplifying system. The fine control also involves a negative regulatory factor, ntrR. When ntrR is mutated, more efficient nodule formation and nitrogen fixation is observed in symbiosis with alfalfa even in the presence of ammonium. The biosynthesis of the second bacterial signal succinoglycan is also controlled by ammonium. SyrM, a common regulatory factor for nod and exo gene expression, may contribute to the adjustment of the amount of succinoglycan and the ratio of its biologically active form.

  15. Production and characterization of bacterial cellulose membranes with hyaluronic acid from chicken comb.

    Science.gov (United States)

    de Oliveira, Sabrina Alves; da Silva, Bruno Campos; Riegel-Vidotti, Izabel Cristina; Urbano, Alexandre; de Sousa Faria-Tischer, Paula Cristina; Tischer, Cesar Augusto

    2017-04-01

    The bacterial cellulose (BC), from Gluconacetobacter hansenii, is a biofilm with a high degree of crystallinity that can be used for therapeutic purposes and as a candidate for healing wounds. Hyaluronic acid (HA) is a constitutive polysaccharide found in the extracellular matrix and is a material used in tissue engineering and scaffolding for tissue regeneration. In this study, polymeric composites were produced in presence of hyaluronic acid isolated from chicken comb on different days of fermentation, specifically on the first (BCHA-SABT0) and third day (BCHA-SABT3) of fermentation. The structural characteristics, thermal stability and molar mass of hyaluronic acid from chicken comb were evaluated. Native membrane and polymeric composites were characterized with respect to their morphology and crystallinity. The optimized process of extraction and purification of hyaluronic acid resulted in low molar mass hyaluronic acid with structural characteristics similar to the standard commercial hyaluronic acid. The results demonstrate that the polymeric composites (BC/HA-SAB) can be produced in situ. The membranes produced on the third day presented better incorporation of HA-SAB between cellulose microfiber, resulting in membranes with higher thermal stability, higher roughness and lower crystallinity. The biocompatiblily of bacterial cellulose and the importance of hyaluronic acid as a component of extracellular matrix qualify the polymeric composites as promising biomaterials for tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Genetic control of cuticular wax compounds in Eucalyptus globulus.

    Science.gov (United States)

    Gosney, Benjamin J; Potts, Brad M; O'Reilly-Wapstra, Julianne M; Vaillancourt, René E; Fitzgerald, Hugh; Davies, Noel W; Freeman, Jules S

    2016-01-01

    Plant cuticular wax compounds perform functions that are essential for the survival of terrestrial plants. Despite their importance, the genetic control of these compounds is poorly understood outside of model taxa. Here we investigate the genetic basis of variation in cuticular compounds in Eucalyptus globulus using quantitative genetic and quantitative trait loci (QTL) analyses. Quantitative genetic analysis was conducted using 246 open-pollinated progeny from 13 native sub-races throughout the geographic range. QTL analysis was conducted using 112 clonally replicated progeny from an outcross F2 population. Nine compounds exhibited significant genetic variation among sub-races with three exhibiting signals of diversifying selection. Fifty-two QTL were found with co-location of QTL for related compounds commonly observed. Notable among these was the QTL for five wax esters, which co-located with a gene from the KCS family, previously implicated in the biosynthesis of cuticular waxes in Arabidopsis. In combination, the QTL and quantitative genetic analyses suggest the variation and differentiation in cuticular wax compounds within E. globulus has a complex genetic origin. Sub-races exhibited independent latitudinal and longitudinal differentiation in cuticular wax compounds, likely reflecting processes such as historic gene flow and diversifying selection acting upon genes that have diverse functions in distinct biochemical pathways. © 2015 University of Tasmania New Phytologist © 2015 New Phytologist Trust.

  17. 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.

  18. Optimization of rhamnolipid production by biodegrading bacterial isolates using Plackett-Burman design.

    Science.gov (United States)

    Hassan, Mariam; Essam, Tamer; Yassin, Aymen S; Salama, Aisha

    2016-01-01

    Biosurfactants are biological surfactants produced by microorganisms. Pseudomonas species are well known for the production of the rhamnolipid biosurfactant. In this work, the production of rhamnolipid biosurfactant by Pseudomonas spp. was investigated and further optimized. Two Plackett-Burman designs to study the effect of carbon source, nitrogen source, C/N ratio, iron concentration, magnesium concentration, phenol toxicity, pH, temperature, agitation and sampling time were tested. The first design revealed an optimization that increased biosurfactant productivity by almost two to fivefolds for the tested isolates. However, using the second design showed no remarkable increase in biosurfactant productivity. An additional validation run was adopted using the predicted optimal medium with predicted optimal conditions. The validation run showed remarkable increase in the productivity of the tested isolates. The use of microorganisms with biodegradation ability coupled with optimization of the parameters affecting productivity provides an efficient strategy for biosurfactant production. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Influence of waxing coupled to 1-methylcyclopropene on compositional changes in early harvested ‘gold’ pineapple for export

    Directory of Open Access Journals (Sweden)

    Francisca Ligia de Castro Machado

    2014-04-01

    Full Text Available This work evaluated the changes in quality in early-harvested ‘Gold’ pineapple after coating with wax and exposure to 1-Methylcycloprepene before or after coating. The storage conditions and the experimental period simulated those of shipping and marketing, assuming that Ceará,Brazil, is the production site andEuropeis the marketplace. Evaluation was performed after harvest, upon removal of the fruit from cold storage, and every three days during room storage. Evaluations included visual quality of the fruit, shell yellowing, mass loss, flesh color, soluble solids, titratable acidity, pH, soluble solids to acid ratio, ascorbic acid, total soluble sugars, reducing sugar, phenolic content, and yellow flavonoids. Low temperature was the key variable for maintaining fruit quality during storage and simulated shipping. Waxing had a remarkable effect on visual quality, delaying yellowing and reducing shell dehydration. Those effects were not enhanced by the application of 1-MCP. 1-MCP treatment resulted in the maintenance of total phenolic content and retention of yellow flavonoids. Fruit flesh became lighter, while yellow color became more vivid during storage. Sugars and pH varied little during storage, while the decline in TA was more intense in waxed fruit. 1-MCP and waxing may be combined to preserve external and internal quality.

  20. 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)

  1. 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.

  2. 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.

  3. An Internal Reference Control Duplex Real-Time Polymerase Chain Reaction Assay for Detecting Bacterial Contamination in Blood Products.

    Directory of Open Access Journals (Sweden)

    Jin-Ju Zhang

    Full Text Available Real-time polymerase chain reaction (RT-PCR enables effective and sensitive screening for infectious risk in the field of blood safety. However, when using RT-PCR to detect bacterial contamination, several intractable points must be considered, one of which is the lack of appropriate quality control. In this study, we developed a simplified RT-PCR assay in which the same primer set and two distinct probes were used to detect both, an internal reference control and the target in a reaction. The copy number of the internal reference control represents the positive detection limit of the assay; therefore, when the threshold-cycle value of the target is less than or equal to that of the internal reference control, the result obtained for the target can be considered to be a true positive. When human gDNA was spiked with Escherichia coli gDNA and the detection limit for the internal reference control was set to five copies, the measured detection limit for E. coli gDNA was two copies. The internal reference control duplex RT-PCR assay showed high efficiency (0.91-1.02, high linearity (R2 > 0.99, and good reproducibility in intra- and inter-assay comparisons. Lastly, when human platelet-rich plasma samples were spiked with E. coli or other bacterial species, all species were detected efficiently, and the results of a two-sample pooled t test showed that the limit of detection for E. coli was 1 cfu/mL. Here, we present a synthetic internal reference control molecule and a new statistical method for improving the reliability of RT-PCR assays when screening for bacterial contamination in blood products.

  4. Human β-defensin-2 production upon viral and bacterial co-infection is attenuated in COPD.

    Science.gov (United States)

    Arnason, Jason W; Murphy, James C; Kooi, Cora; Wiehler, Shahina; Traves, Suzanne L; Shelfoon, Christopher; Maciejewski, Barbara; Dumonceaux, Curtis J; Lewenza, W Shawn; Proud, David; Leigh, Richard

    2017-01-01

    Viral-bacterial co-infections are associated with severe exacerbations of COPD. Epithelial antimicrobial peptides, including human β-defensin-2 (HBD-2), are integral to innate host defenses. In this study, we examined how co-infection of airway epithelial cells with rhinovirus and Pseudomonas aeruginosa modulates HBD-2 expression, and whether these responses are attenuated by cigarette smoke and in epithelial cells obtained by bronchial brushings from smokers with normal lung function or from COPD patients. When human airway epithelial cells from normal lungs were infected with rhinovirus, Pseudomonas aeruginosa, or the combination, co-infection with rhinovirus and bacteria resulted in synergistic induction of HBD-2 (p<0.05). The combination of virus and flagellin replicated this synergistic increase (p<0.05), and synergy was not seen using a flagella-deficient mutant Pseudomonas (p<0.05). The effects of Pseudomonas aeruginosa were mediated via interactions of flagellin with TLR5. The effects of HRV-16 depended upon viral replication but did not appear to be mediated via the intracellular RNA helicases, retinoic acid-inducible gene-I or melanoma differentiation-associated gene-5. Cigarette smoke extract significantly decreased HBD-2 production in response to co-infection. Attenuated production was also observed following co-infection of cells obtained from healthy smokers or COPD patients compared to healthy controls (p<0.05). We conclude that co-exposure to HRV-16 and Pseudomonas aeruginosa induces synergistic production of HBD-2 from epithelial cells and that this synergistic induction of HBD-2 is reduced in COPD patients. This may contribute to the more severe exacerbations these patients experience in response to viral-bacterial co-infections.

  5. Human β-defensin-2 production upon viral and bacterial co-infection is attenuated in COPD.

    Directory of Open Access Journals (Sweden)

    Jason W Arnason

    Full Text Available Viral-bacterial co-infections are associated with severe exacerbations of COPD. Epithelial antimicrobial peptides, including human β-defensin-2 (HBD-2, are integral to innate host defenses. In this study, we examined how co-infection of airway epithelial cells with rhinovirus and Pseudomonas aeruginosa modulates HBD-2 expression, and whether these responses are attenuated by cigarette smoke and in epithelial cells obtained by bronchial brushings from smokers with normal lung function or from COPD patients. When human airway epithelial cells from normal lungs were infected with rhinovirus, Pseudomonas aeruginosa, or the combination, co-infection with rhinovirus and bacteria resulted in synergistic induction of HBD-2 (p<0.05. The combination of virus and flagellin replicated this synergistic increase (p<0.05, and synergy was not seen using a flagella-deficient mutant Pseudomonas (p<0.05. The effects of Pseudomonas aeruginosa were mediated via interactions of flagellin with TLR5. The effects of HRV-16 depended upon viral replication but did not appear to be mediated via the intracellular RNA helicases, retinoic acid-inducible gene-I or melanoma differentiation-associated gene-5. Cigarette smoke extract significantly decreased HBD-2 production in response to co-infection. Attenuated production was also observed following co-infection of cells obtained from healthy smokers or COPD patients compared to healthy controls (p<0.05. We conclude that co-exposure to HRV-16 and Pseudomonas aeruginosa induces synergistic production of HBD-2 from epithelial cells and that this synergistic induction of HBD-2 is reduced in COPD patients. This may contribute to the more severe exacerbations these patients experience in response to viral-bacterial co-infections.

  6. 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.

  7. 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

  8. 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

  9. A survey of fermentation products and bacterial communities in corn silage produced in a bunker silo in China.

    Science.gov (United States)

    Wang, Chao; Han, Hongyan; Gu, Xueying; Yu, Zhu; Nishino, Naoki

    2014-01-01

    To evaluate the current practice of corn silage management in China, samples of bunker-made silage were collected from 14 farms within a 500-km radius of Beijing for the analysis of fermentation products and bacterial communities. Mean values for dry matter (DM) content were as low as 250 g/kg in both corn stover (St) and whole crop corn (Wc) silages, and pH values averaged 4.48 and 3.73, respectively. Only three of the 14 silages exhibited a lactic-to-acetic acid ratio > 1.0, indicating that the presence of acetic acid was predominant in fermentation. Although 1,2-propanediol content was marginal in most cases ( 25 g/kg DM. In contrast, 3 St silages had large amounts (> 10 g/kg DM) of butyric acid, and two of the three butyrate silages also had high concentrations of 1-propanol. Denaturing gradient gel electrophoresis analysis demonstrated that the bacterial community appeared similar in 10 out of the 14 silage samples. Bands indicating Lactobacillus buchneri, L. acetotolerans and Acetobacter pasteurianus were found in both the St and Wc silages, accounting for the high acetic acid content found across silage samples. © 2013 Japanese Society of Animal Science.

  10. Bacterial biomes and potential human pathogens in irrigation water and leafy greens from different production systems described using pyrosequencing.

    Science.gov (United States)

    Jongman, M; Chidamba, L; Korsten, L

    2017-10-01

    To investigate the influence of irrigation water microbial quality on leafy green vegetables produced in commercial and small-scale farms as well as homestead gardens using pyrosequencing. Next generation sequencing analysis of the V1-V3 hypervariable region of bacterial 16S rDNA was used to compare bacterial diversity in irrigation water sources and on leafy vegetables. In all samples (12) analysed, the phylum Proteobacteria (64·5%), class Gammaproteobacteria (56·6%) and genus Aeromonas (14·4%) were found to be dominant. Of the total Escherichia sequences detected in tested samples, lettuce (16·3%) from the one commercial farm harboured more sequences than cabbage from the small-scale farm (1·3%) or homestead gardens (1·9%). Escherichia sequences were detected in both irrigation water (4·6%) and on cabbage (1·3%) samples from the small-scale farm. The genus Salmonella was absent in borehole water but was detected in the holding dam water (biomes in irrigation water and on leafy greens were described with pyrosequencing and revealed insights into prevalence of potential and opportunistic pathogens across different production systems. © 2017 The Society for Applied Microbiology.

  11. 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.

  12. Biogas production from coumarin-rich plants--inhibition by coumarin and recovery by adaptation of the bacterial community.

    Science.gov (United States)

    Popp, Denny; Schrader, Steffi; Kleinsteuber, Sabine; Harms, Hauke; Sträuber, Heike

    2015-09-01

    Plants like sweet clover (Melilotus spp.) are not suitable as fodder for cattle because of harmful effects of the plant secondary metabolite coumarin. As an alternative usage, the applicability of coumarin-rich plants as substrates for biogas production was investigated. When coumarin was added to continuous fermentation processes codigesting grass silage and cow manure, it caused a strong inhibition noticeable as decrease of biogas production by 19% and increase of metabolite concentrations to an organic acids/alkalinity ratio higher than 0.3(gorganic acids) gCaCO3 (-1). Microbial communities of methanogenic archaea were dominated by the genera Methanosarcina (77%) and Methanoculleus (11%). This community composition was not influenced by coumarin addition. The bacterial community analysis unraveled a divergence caused by coumarin addition correlating with the anaerobic degradation of coumarin and the recovery of the biogas process. As a consequence, biogas production resumed similar to the coumarin-free control with a biogas yield of 0.34 LN g(volatile solids) (-1) and at initial metabolite concentrations (∼ 0.2 g(organic acids) gCaCO3 (-1)). Coumarin acts as inhibitor and as substrate during anaerobic digestion. Hence, coumarin-rich plants might be suitable for biogas production, but should only be used after adaptation of the microbial community to coumarin. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Statistical optimization of medium components and physicochemical parameters to simultaneously enhance bacterial growth and esterase production by Bacillus thuringiensis.

    Science.gov (United States)

    Mazzucotelli, Cintia Anabela; Moreira, María del Rosario; Ansorena, María Roberta

    2016-01-01

    Bacillus thuringiensis is a genus extensively studied because of its high potential for biotechnological application, principally in biocontrol techniques. However, the optimization of esterase production by this strain has been scarcely studied. The aim of this work was to select and optimize the physicochemical and nutritional parameters that significantly influence the growth and esterase production of B. thuringiensis. To this purpose, 6 nutritional factors and 2 physicochemical parameters were evaluated using a Plackett-Burman design. Significant variables were optimized using a Box-Behnken design and through the desirability function to select the levels of the variables that simultaneously maximize microbial growth and esterase production. The optimum conditions resulting from simultaneous optimization of the responses under study were found to be 1 g/L glucose, 15 g/L peptone, and 3.25 g/L NaCl. Under these optimal conditions, it was possible to achieve a 2.5 log CFU/mL increase in bacterial growth and a 113-fold increase in esterase productivity, compared with minimal medium without agitation.

  14. 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; Perera, Varahenage Ranmali; Aguilar, Julieta; Liu, Wei-Ting; Dorrestein, Pieter C.; Pogliano, Joe; Pogliano, Kit

    2016-01-01

    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. PMID:26648120

  15. 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.

  16. 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

  17. Cytotoxicity of Bacterial Metabolic Products, including Listeriolysin O, on Leukocyte Targets

    Directory of Open Access Journals (Sweden)

    R. Stachowiak

    2012-01-01

    Full Text Available Bacterial toxins can exhibit anticancer activities. Here we investigated the anticancer effects of the listeriolysin O toxin produced by Listeria monocytogenes. We found that supernatants of Listeria monocytogenes strains (wild type, 1189, and 1190 were cytotoxic to the Jurkat cell line and human peripheral blood mononuclear cells (PBMC in a concentration-dependent manner. The supernatant of strain 1044, not producing listeriolysin O, was inactive. The supernatants of Listeria strains were also cytotoxic toward B cells of chronic leukemia patients, with no significant differences in activities between strains. We also tested supernatants of Bacillus subtilis strains BR1-90, BR1-S, and BR1-89 producing listeriolysin O. BR1-S and BR1-89 were cytotoxic to PBMC and to Jurkat cells, the latter being more sensitive to the supernatants. BR1-90 was not hemolytic or cytotoxic to PBMC, but was cytotoxic to Jurkat cells in the concentration range of 10–30%, suggesting that listeriolysin O is selectively effective against T cells. Overall, the response of human peripheral blood mononuclear and human leukemia cell lines to bacteria supernatants containing listeriolysin O depended on the bacteria strain, target cell type, and supernatant concentration.

  18. 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.

  19. 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......B) encoding enzymes catalysing the conversion of pyruvate to ethanol. Additionally a number of genes (Idh, pta and adhE) are deleted in order to maximise homo-ethanol production as compared to production of lactate, acetoin and acetate production.......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 liquor......). The invention further relates to genetically modified lactic acid bacterium and its use for homo-ethanol production from lactose in dairy waste. The lactic acid bacterium comprises both genes (lacABCD, LacEF, lacG) encoding enzymes catalysing the lactose catabolism pathway; and transgenes (pdc and adh...

  20. Influence of Thermal and Bacterial Pretreatment of Microalgae on Biogas Production in Mesophilic and Thermophilic Conditions.

    Science.gov (United States)

    Vidmar, Beti; Marinšek Logar, Romana; Panjičko, Mario; Fanedl, Lijana

    2017-01-01

    Microalgae biomass has a great potential in search for new alternative energy sources. They can be used as a substrate for the biogas production in anaerobic digestion. When using microalgae, the efficiency of this process is hampered due to the resistant cell wall. In order to accelerate the hydrolysis of cell wall and increase the efficiency of biogas production we applied two different pretreatments - biological and thermal under mesophilic and thermophilic conditions. During biological pretreatment we incubated microalgae with anaerobic hydrolytic bacteria Pseudobutyrivibrio xylanivorans Mz5T. In thermal pretreatment we incubated microalgae at 90 °C. We also tested a combined thermal and biological pretreatment in which we incubated P. xylanivorans Mz5T with thermally pretreated microalgae. Thermal pretreatment in mesophilic and thermophilic process has increased methane production by 21% and 6%, respectively. Biological pretreatment of microalgae has increased methane production by 13%, but only under thermophilic conditions (pretreatment under mesophilic conditions showed no effect on methane production). Thermal-biological pretreatment increased methane production by 12% under thermophilic conditions and by 6% under mesophilic conditions.

  1. SUPERKILLER Complex Components Are Required for the RNA Exosome-Mediated Control of Cuticular Wax Biosynthesis in Arabidopsis Inflorescence Stems.

    Science.gov (United States)

    Zhao, Lifang; Kunst, Ljerka

    2016-06-01

    ECERIFERUM7 (CER7)/AtRRP45B core subunit of the exosome, the main cellular 3'-to-5' exoribonuclease, is a positive regulator of cuticular wax biosynthesis in Arabidopsis (Arabidopsis thaliana) inflorescence stems. CER7-dependent exosome activity determines stem wax load by controlling transcript levels of the wax-related gene CER3 Characterization of the second-site suppressors of the cer7 mutant revealed that small interfering RNAs (siRNAs) are direct effectors of CER3 expression. To explore the relationship between the exosome and posttranscriptional gene silencing (PTGS) in regulating CER3 transcript levels, we investigated two additional suppressor mutants, wax restorer1 (war1) and war7. We show that WAR1 and WAR7 encode Arabidopsis SUPERKILLER3 (AtSKI3) and AtSKI2, respectively, components of the SKI complex that associates with the exosome during cytoplasmic 3'-to-5' RNA degradation, and that CER7-dependent regulation of wax biosynthesis also requires participation of AtSKI8. Our study further reveals that it is the impairment of the exosome-mediated 3'-5' decay of CER3 transcript in the cer7 mutant that triggers extensive production of siRNAs and efficient PTGS of CER3. This identifies PTGS as a general mechanism for eliminating highly abundant endogenous transcripts that is activated when 3'-to-5' mRNA turnover by the exosome is disrupted. Diminished efficiency of PTGS in ski mutants compared with cer7, as evidenced by lower accumulation of CER3-related siRNAs, suggests that reduced amounts of CER3 transcript are available for siRNA synthesis, possibly because CER3 mRNA that does not interact with SKI is degraded by 5'-to-3' XRN4 exoribonuclease. © 2016 American Society of Plant Biologists. All Rights Reserved.

  2. Variation for epicuticular waxes on onion foliage and impacts on numbers of onion thrips

    Science.gov (United States)

    Natural variation exists in onion for amounts of epicuticular waxes on foliage, and plants with lower amounts of these waxes suffer less damage from the insect pest Thrips tabaci (thrips). Wild-type onion possesses copious amounts of epicuticular waxes and is often referred to as “waxy”. The recessi...

  3. Epicuticular waxes on onion leaves and associated resistance to onion thrips

    Science.gov (United States)

    Natural variation exists for amounts and types of epicuticular waxes on onion foliage. Wild-type onion possesses copious amounts of these waxes and is often referred to as “waxy”. The recessively inherited “glossy” phenotype has significantly less wax relative to waxy types and shows resistance to o...

  4. 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

  5. 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.

  6. Synthetic biology approaches for protein production optimization in bacterial cell factories

    DEFF Research Database (Denmark)

    Rennig, Maja; Andersen, Mikael Rørdam

    such sustainable alternative if converted into so-called microbial cell factories. Instead of crude oil, cell factories use renewable resources or waste products as source material. The challenge is, however, that microbial production needs to be economically feasible to compete with the classical chemical...... devices and their fusion to antibiotic selection markers enables subsequent selection of high-expressing constructs. The approach is a simple and inexpensive alternative to advanced screening techniques. In addition, a second synthetic biology approach provides the means for fast and efficient plasmid......Society’s strong dependence on fossil fuels and petroleum-based products leads not only to a rapid decline of natural oil reserves but contributes massively to global warming and environmental damage. This consequently urges society to look into more sustainable alternatives. Microorganisms present...

  7. [Phenotypic and genotypic characterization of probiotic bacterial strains used in medicinal products].

    Science.gov (United States)

    Wiatrzyk, Aldona; Polak, Maciej; Czajka, Urszula; Krysztopa-Grzybowska, Katarzyna; Lutyńska, Anna

    2013-01-01

    The optimization of quality testing strategy of products containing probiotics might allow to general improvement of its safer use in humans. The goal of the study was the evaluation of quality expressed by identity, colony forming unit (CFU) and antibiotic sensitivity ofprobiotics used in medicinal products available in Poland using the appropriate and validated procedures. The medicinal products containing L. rhamnosus, L. acidophilus, L. delbrueckii subsp. bulgaricus and B. animalis subsp. lactis, L. helveticus, and L. gasseri were tested for species identity performed with validated rep-PCR (BOXA 1R) method. The antimicrobial susceptibility of working seeds and strains isolated to 26 antibiotics were tested by disk diffusion and E-test methods using relevant references as recommended by EUCAST. The numbers of probiotic strains, expressed as cfu count per package, was done using plating plunge method. All strains tested, except B. lactis, were found to be resistant to trimethoprim-sulphamethoxazole, nalidixic acid, metronidazole, and colistin. B. lactis was resistant to aminoglycosides. L. rhamnosus strains were found to be resistant to vancomycin, (MIC > 256 microg/ml) similarly to ATCC strains (L. rhamnosus GG 53103 and 244). The sensitivity to other antibiotics was strain specific. The rep-PCR method was found species and strain specific. All products tested fulfilled declared countent as measured by cfu count/package. Quality of medicinal products containing probiotics was found undoubted and confirmed. The optimized strategy of quality monitoring of probiotics used in medicinal products can be used in dietary supplements and foodstuffs intended for particular nutritional uses.

  8. Bacterial diversity and spoilage-related microbiota associated with freshly prepared chicken products under aerobic conditions at 4°C.

    Science.gov (United States)

    Liang, Rongrong; Yu, Xiaoqiao; Wang, Renhuan; Luo, Xin; Mao, Yanwei; Zhu, Lixian; Zhang, Yimin

    2012-06-01

    This study analyzed the bacterial diversity and spoilage-related microbiota associated with freshly prepared chicken products stored aerobically at 4°C, using "bone and chicken string," a product popular in the People's Republic of China, as the study subject. Samples collected from three different factories were tray packaged with cling film and stored at 4°C. Bacterial diversity and dominant bacteria were analyzed using PCR amplification and denaturing gradient gel electrophoresis. Combined with selective cultivation of the dominant bacteria and correlation analysis, the dominant spoilage microbiota was determined. The results showed that bacterial diversity varied with different manufacturers. Such bacteria as Acinetobacter sp., Carnobacterium sp., Rahnella sp., Pseudomonas sp., Brochothrix sp., and Weissella sp. were detected in freshly prepared chicken products during storage. And Carnobacterium sp., Pseudomonas sp., and Brochothrix sp. bacteria were the common dominant spoilage bacteria groups in most freshly prepared chicken products from different factories. Carnobacterium was, for the first time, shown to be an important contributor to the spoilage-related microflora of freshly prepared chicken products stored aerobically under refrigeration. Our work shows the bacterial diversity and dominant spoilage microbiota of freshly prepared chicken products stored aerobically under refrigeration.

  9. 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.

  10. 75 FR 38121 - Petroleum Wax Candles From China

    Science.gov (United States)

    2010-07-01

    ... paper-cored wicks and containing any amount of petroleum wax, except for candles containing more than 50... investigation. The Commission's designated agency ethics official has advised that a five-year review is not... Office of Government Ethics. Consequently, former employees are not required to seek Commission approval...

  11. Characterization of wax manufactures of historical and artistic interest.

    Science.gov (United States)

    Campanella, Luigi; Chicco, Federica; Colapietro, Marcello; Gatta, Tania; Gregori, Emanuela; Panfili, Manuela; Russo, Mario Vincenzo

    2005-01-01

    Purpose of this scientific research is the physic and chemical characterization of two historical wax manufactures, made at the end of XIX century by Francesco Bianchi, a papal engraver. The chemical and analytical investigation was necessary to complete and to confirm the restorer's work. The IR Spectroscopy, X-Ray and GC-MS, the best technique to characterise wax, allowed us to obtain the following results. The two manufactures were made with commercial beeswax: in fact, the relative chromatograms showed unchanged peaks about esters of palmitic acid with C24 to C32 alcohol molecules; using standard beeswax we determined the same amount of hydrocarbons present in the wax manufactures. We found several hydrocarbons in these beeswax materials so that it is reasonable to think about successive modifications. ZnO (white zinc), a pigment, was added, probably due to its colour and covering capacity. Sb2S3, Anthimoniun vermilion, a red-orange pigment, was added to these manufactures to give them a soft pink-orange colour. By all used techniques we determined some modifications in the original beeswax; surely they were made to get a more malleable, mouldable, and then more able to be modelled wax.

  12. Leaf wax biomarkers in transit record river catchment composition

    Science.gov (United States)

    Ponton, Camilo; West, A. Joshua; Feakins, Sarah J.; Galy, Valier

    2014-09-01

    Rivers carry organic molecules derived from terrestrial vegetation to sedimentary deposits in lakes and oceans, storing information about past climate and erosion, as well as representing a component of the carbon cycle. It is anticipated that sourcing of organic matter may not be uniform across catchments with substantial environmental variability in topography, vegetation zones, and climate. Here we analyze plant leaf wax biomarkers in transit in the Madre de Dios River (Peru), which drains a forested catchment across 4.5 km of elevation from the tropical montane forests of the Andes down into the rainforests of Amazonia. We find that the hydrogen isotopic composition of leaf wax molecules (specifically the C28 n-alkanoic acid) carried by this tropical mountain river largely records the elevation gradient defined by the isotopic composition of precipitation, and this supports the general interpretation of these biomarkers as proxy recorders of catchment conditions. However, we also find that leaf wax isotopic composition varies with river flow regime over storm and seasonal timescales, which could in some cases be quantitatively significant relative to changes in the isotopic composition of precipitation in the past. Our results inform on the sourcing and transport of material by a major tributary of the Amazon River and contribute to the spatial interpretation of sedimentary records of past climate using the leaf wax proxy.

  13. 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...

  14. Preparation and Characterization of Sugar Cane Wax Microspheres ...

    African Journals Online (AJOL)

    HP

    protect the patients against morning stiffness. [8]. Thus, the development of a controlled release formulation of IM ... initial peak plasma concentrations, protection against morning stiffness, prolonged duration of action, improved ..... sugar cane wax and fatty alcohols on serum and liver lipids in the rats. J Nutr Sci Vitaminol.

  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 * soils Subject RIV: AC - Archeology, Anthropology, Ethnology http://www.soil-journal.net/2/551/2016/soil-2-551-2016.pdf

  16. 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 ...

  17. Synthesis of wax in the honeybee (Apis mellifera L.)

    NARCIS (Netherlands)

    Piek, T.

    Newly emerged honeybee workers were fed during 1 or 2 weeks with sucrose containing either heavy water, sodium acetate with deuterium, sodium acetate-1-14C, or uniformly labelled glucose-14C. The various lipid fractions were isolated in order to investigate the origin of the secreted wax components.

  18. 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

  19. The preservative efficacies of bemul-wax coatings in combination ...

    African Journals Online (AJOL)

    All treatments showed significantly increased (p<0.05) pH and -amylase activities but no effects on total sugar levels, pectin esterase activities, taste and flavor of the juice. In conclusion, the combined and bemul-wax treatments preserved the nutritional, biochemical, and sensory qualities of the stored oranges for the four ...

  20. 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 ...

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

    African Journals Online (AJOL)

    NJD

    2005-12-22

    Dec 22, 2005 ... Young's modulus depends on the interaction between the crystalline and amorphous regions, due to the elongation energy to be transmitted from the amorphous to the crystalline phase. The interaction between the wax (partially crystallized in the amorphous phase of the polymer) and polyethylene chains.

  2. Release Characteristics of Diltiazem Hydrochloride Wax-Matrix ...

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRACT: The aim of this study was to investigate the release characteristics of matrix (non-disintegrating) granules consisting of diltiazem hydrochloride (model drug) and glyceryl behenate (a wax matrix forming polymer) for sustained release application using sintering technique. The granules of diltiazem ...

  3. Variation for epicuticular waxes and thrips resistance in onion

    Science.gov (United States)

    Onion thrips (Thrips tabaci) and thrips-vectored Iris Yellow Spot Virus (IYSV) routinely cause significant losses to the bulb and seed crops of onion. Both pests have become more problematic as global temperatures rise. Natural variation exists in onion for amounts and types of epicuticular waxes on...

  4. Wax Spreading in Paper under Controlled Pressure and Temperature.

    Science.gov (United States)

    Hong, Wei; Zhou, Jing; Kanungo, Mandakini; Jia, Nancy; Dinsmore, Anthony D

    2018-01-09

    This work describes a novel rapid method to fabricate high-resolution paper-based microfluidic devices using wax-ink-based printing. This study demonstrates that both temperature and pressure are important knobs in controlling the device resolution. High-resolution lines and patterns were obtained by heating the paper asymmetrically from one side up to 110 °C while applying pressure up to 49 kPa. Starting with wax lines with an initial width of 130 μm, we achieve a thorough penetration through a 190 μm-thick paper with lateral spreading on the front as narrow as 90 μm. The role of temperature and pressure are systematically studied and compared with the prediction of the Lucas-Washburn equation. We found that the temperature dependence of spreading can be explained by the viscosity change of the wax, according to the Lucas-Washburn equation. The pressure dependence deviates from Lucas-Washburn behavior because of compression of the paper. An optimal condition for achieving full depth penetration of the wax yet minimizing lateral spreading is suggested after exploring various parameters including temperature, pressure, and paper type. These findings could lead to a rapid roll-to-roll fabrication of high-resolution paper-based diagnostic devices.

  5. 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.

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

    African Journals Online (AJOL)

    The influence of three different waxes on the thermal and mechanical properties of linear low-density polyethylene (LLDPE) was investigated. The samples were prepared through melt blending in a Brabender mixer. The thermal properties of the samples were determined using differential scanning calorimetry (DSC) and ...

  7. Characterization of Epoxy Composites Reinforced with Wax Encapsulated Microcrystalline Cellulose

    Directory of Open Access Journals (Sweden)

    Yuanfeng Pan

    2016-11-01

    Full Text Available The effect of paraffin wax encapsulated microcrystalline cellulose (EMC particles on the mechanical and physical properties of EMC/epoxy composites were investigated. It was demonstrated that the compatibility between cellulose and epoxy resin could be maintained due to partial encapsulation resulting in an improvement in epoxy composite mechanical properties. This work was unique because it was possible to improve the physical and mechanical properties of the EMC/epoxy composites while encapsulating the microcrystalline cellulose (MCC for a more homogeneous dispersion. The addition of EMC could increase the stiffness of epoxy composites, especially when the composites were wet. The 1% EMC loading with a 1:2 ratio of wax:MCC demonstrated the best reinforcement for both dry and wet properties. The decomposition temperature of epoxy was preserved up to a 5% EMC loading and for different wax:MCC ratios. An increase in wax encapsulated cellulose loading did increase water absorption but overall this absorption was still low (<1% for all composites.

  8. Probiotics, immunostimulants, plant products and oral vaccines, and their role as feed supplements in the control of bacterial fish diseases.

    Science.gov (United States)

    Newaj-Fyzul, A; Austin, B

    2015-11-01

    There is a rapidly increasing literature pointing to the success of probiotics, immunostimulants, plant products and oral vaccines in immunomodulation, namely stimulation of the innate, cellular and/or humoral immune response, and the control of bacterial fish diseases. Probiotics are regarded as live micro-organisms administered orally and leading to health benefits. However, in contrast with the use in terrestrial animals, a diverse range of micro-organisms have been evaluated in aquaculture with the mode of action often reflecting immunomodulation. Moreover, the need for living cells has been questioned. Also, key subcellular components, including lipopolysaccharides, have been attributed to the beneficial effect in fish. Here, there is a link with immunostimulants, which may also be administered orally. Furthermore, numerous plant products have been reported to have health benefits, namely protection against disease for which stimulation of some immune parameters has been reported. Oral vaccines confer protection against some diseases, although the mode of action is usually linked to humoral rather than the innate and cellular immune responses. This review explores the relationship between probiotics, immunostimulants, plant products and oral vaccines. © 2014 John Wiley & Sons Ltd.

  9. 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.

  10. Bacterial quality of a smoked meat product (“Suya”) | Inyang ...

    African Journals Online (AJOL)

    Isolation of faecal coliforms from all samples in this investigation should be a serious concern to consumers. This calls for urgent improvement on the hygienic handling of the product by suya processors. Keywords: suya, faecal coliforms, contamination, bacteriological quality, hygienic conditions. Nigerian Food Journal Vol.

  11. 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).

  12. 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 ...

  13. 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

  14. 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

    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...

  15. A bicistronic expression system for bacterial production of authentic human interleukin-18.

    Science.gov (United States)

    Kirkpatrick, Robert B; McDevitt, Patrick J; Matico, Rosalie E; Nwagwu, Silas; Trulli, Stephen H; Mao, Joyce; Moore, Dwight D; Yorke, Adam F; McLaughlin, Megan M; Knecht, Kristin A; Elefante, Louis C; Calamari, Amy S; Fornwald, Jim A; Trill, John J; Jonak, Zdenka L; Kane, James; Patel, Pramathesh S; Sathe, Ganesh M; Shatzman, Allan R; Tapley, Peter M; Johanson, Kyung O

    2003-02-01

    Interleukin-18 (IL-18) is activated and released from immune effector cells to stimulate acquired and innate immune responses involving T and natural killer (NK) cells. The release of IL-18 from mammalian cells is linked to its proteolytic activation by caspases including interleukin 1 converting enzyme (ICE). The absence of a signal peptide sequence and the requirement for coupled activation and cellular release have presented challenges for the large-scale recombinant production of IL-18. In this study, we have explored methods for the direct production of authentic human IL-18 toward the development of a large-scale production system. Expression of mature IL-18 directly in Escherichia coli with a methionine initiating codon leads to the production of MetIL-18 that is dramatically less potent in bioassays than IL-18 produced as a pro-peptide and activated in vitro. To produce an authentic IL-18, we have devised a bicistronic expression system for the coupled transcription and translation of ProIL-18 with caspase-1 (ICE) or caspase-4 (ICE-rel II, TX, ICH-2). Mature IL-18 with an authentic N-terminus was produced and has a biological activity and potency comparable to that of in vitro processed mature IL-18. Optimization of this system for the maximal production yields can be accomplished by modulating the temperature, to affect the rate of caspase activation and to favor the accumulation of ProIL-18, prior to its proteolytic processing by activated caspase. The effect of temperature is particularly profound for the caspase-4 co-expression process, enabling optimized production levels of over 150 mg/L in shake flasks at 25 degrees C. An alternative bicistronic expression design utilizing a precise ubiquitin IL-18 fusion, processed by co-expressed ubiquitinase, was also successfully used to generate fully active IL-18, thereby demonstrating that the pro-sequence of IL-18 is not required for recombinant IL-18 production. Copyright 2002 Elsevier Science (USA)

  16. 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.

  17. Hydrogen production and anaerobic decolorization of wastewater containing Reactive Blue 4 by a bacterial consortium of Salmonella subterranea and Paenibacillus polymyxa.

    Science.gov (United States)

    Watanapokasin, Ramida Yuwadee; Boonyakamol, Anantabhathra; Sukseree, Supawadee; Krajarng, Aungkana; Sophonnithiprasert, Thanet; Kanso, Sungwan; Imai, Tsuyoshi

    2009-06-01

    Anaerobic biodegradability of wastewater (3,000 mg CODcr/l) containing 300 mg/l Reactive Blue 4, with different co-substrates, glucose, butyrate and propionate by a bacterial consortium of Salmonella subterranea and Paenibacillus polymyxa, concomitantly with hydrogen production was investigated at 35 degrees C. The accumulative hydrogen production at 3,067 mg CODcr/l was obtained after 7 days of incubation with glucose, sludge, the bacterial consortium. The volatile fatty acids, residual glucose and the total organic carbon were correlated to hydrogen obtained. Interestingly, the bacterial consortium possess decolorization ability showing approximately 24% dye removal after 24 h incubation using glucose as a co-substrate, which was about two and eight times those of butyrate (10%), propionate (12%) and control (3%), respectively. RB4 decolorization occurred through acidogenesis, as high volatile fatty acids but low methane was detected. The bacterial consortium will be the bacterial strains of interest for further decolorization and hydrogen production of industrial waste water.

  18. Cuticular wax coverage and composition differ among organs of Taraxacum officinale.

    Science.gov (United States)

    Guo, Yanjun; Busta, Lucas; Jetter, Reinhard

    2017-06-01

    Primary plant surfaces are coated with hydrophobic cuticular waxes to minimize non-stomatal water loss. Wax compositions differ greatly between plant species and, in the few species studied systematically so far, also between organs, tissues, and developmental stages. However, the wax mixtures of more species in diverse plant families must be investigated to assess overall wax variability, and ultimately to correlate organ-specific composition with local water barrier properties. Here, we present comprehensive analyses of the waxes covering five organs of Taraxacum officinale (dandelion), to help close a gap in our understanding of wax chemistry in the Asteraceae family. First, novel wax constituents of the petal wax were identified as C 25 6,8- and 8,10-ketols as well as C 27 6,8- and 8,10-ketols. Nine other component classes (fatty acids, primary alcohols, esters, aldehydes, alkanes, triterpenols, triterpene acetates, sterols, and tocopherols) were detected in the wax mixtures covering leaves, peduncles, and petals, as well as fruit beaks and pappi. Wax coverages varied from 5 μg/cm 2 on peduncles to 37 μg/cm 2 on petals. Alcohols predominated in leaf wax, while both alcohols and alkanes were found in similar amounts on peduncles and petals, and mainly alkanes on the fruit beaks and pappi. Chain length distributions within the wax compound classes were similar between organs, centered around C 26 for fatty acids, alcohols, and aldehydes, and C 29 for alkanes. However, the quantities of homologs with longer chain lengths varied substantially between organs, reaching well beyond C 30 on all surfaces except leaves, suggesting differences in elongation enzymes determining the alkyl chain structures. The detailed wax profiles presented here will serve as basis for future investigations into wax biosynthesis in the Asteraceae and into wax functions on different dandelion organs. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. 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.

  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. Strategies for production of active eukaryotic proteins in bacterial expression system

    OpenAIRE

    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.

  2. Tear production, intraocular pressure and conjunctival bacterial flora in selected captive wild ruminants.

    Science.gov (United States)

    Kvapil, Pavel; Pirš, Tina; Slavec, Brigita; Luštrik, Roman; Zemljič, Tadej; Bártová, Eva; Stranjac, Bojana; Kastelic, Marjan

    2018-01-01

    Evaluation of tear production (Schirmer's tear test, STT) and measurement of intraocular pressure (IOP) were performed in a population of captive wild ungulates in a Slovenian ZOO during routine annual health check. In total, 10 fallow deer (Dama dama), 25 mouflons (Ovis aries musimon), 20 alpine ibexes (Capra ibex), and three alpine chamois (Rupicapra rupicapra) were included in the study. Tear production was performed by Schirmer's tear test, IOP was measured with an applanation tonometer, and ophthalmological examination was conducted with slit-lamp biomicroscopy and indirect ophthalmoscopy. Conjunctival swabs were taken and submitted for aerobic bacteriology and for detection of Chlamydia spp. and Mycoplasma spp. tested by PCR. Average tear production (in mm/min) was 17.8 ± 3.16 for fallow deer, 17.9 ± 3.87 for mouflons, and 11.7 ± 3.87 for ibexes. Mean intraocular pressure (IOP, in mm Hg) was 14.1 ± 2.48 for fallow deer, 14.9 ± 2.20 for mouflons, and 13.1 ± 2.43 for ibexes. For chamois, average tear production and IOP were 14.5 ± 3.0 and 10.2 ± 2.5, respectively; this is the first record of STT I and IOP in chamois. Bacteriological swabs were positive for bacteria in 100% of the fallow deer, 56% of mouflons, 35% of ibexes, and 100% of chamois. Gram-positive bacteria were predominant. Moraxella spp., Chlamydia spp., and Mycoplasma spp. were not detected. The reported values were obtained in animals under manual restraint only to be applicative in similar conditions. © 2017 American College of Veterinary Ophthalmologists.

  3. Marine Fungal and Bacterial Isolates for Lipase Production: A Comparative Study.

    Science.gov (United States)

    Patnala, H S; Kabilan, U; Gopalakrishnan, L; Rao, R M D; Kumar, D S

    Lipases, belonging to the class of enzymes called hydrolases, can catalyze triglycerides to fatty acids and glycerol. They are produced by microbes of plant and animal origin, and also by marine organisms. As marine microorganisms thrive in extreme conditions, lipases isolated from their origin possess characteristics of extremozymes, retain its activity in extreme conditions and can catalyze few chemical reactions which are impossible otherwise relative to the lipase produced from terrestrial microorganisms. Lipases are useful in many industries like detergent, food, leather, pharmaceutical, diary, etc. Few commercial enzymes have been developed and the use of them in certain industries like dairy, soaps are proved to be beneficial. There are few research papers reporting the production of lipase from marine bacteria and fungi. Lipase production involves two types of fermentation processes-solid-state fermentation (SSF) and submerged fermentation (SmF). Although SmF process is used conventionally, SSF process produces lipase in higher amounts. The production is also influenced by the composition of the medium, physiochemical parameters like temperature, pH, carbon, and nitrogen sources. © 2016 Elsevier Inc. All rights reserved.

  4. 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.

  5. 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.

  6. The molecular signatures of Taxodiaceae / Cupressaceae / Taxaceae (TCT) leaf waxes in modern and ancient samples

    Science.gov (United States)

    Ho, M.; Zinniker, D.; Green Nylen, N.; Moldowan, J. M.; Denisevich, P.

    2005-12-01

    Members of the Taxodiaceae/Cupressaceae/Taxaceae (TCT) complex of conifers originated sometime before the late Jurassic. Since that time the group has diverged to fill diverse ecological niches in desert, marsh, tundra, alpine, and coastal habitats and a variety of forest types. 175 species from 35 genera are now found across 6 continents. The aims of this research project are 1) to analyze and describe cuticular isoprenoid and acetogenic lipids from a diverse group of living members of the TCT complex and 2) to begin a search for these compounds and their diagenetic products in geological samples with known contributions from ancient TCT members. Hexane extracts of several hundred modern conifer specimens from more than 25 genera were studied in an attempt to find phylogenetic trends in the distribution and abundance of wax components. Diverse skeletal types of bicyclic, tricyclic, and tetracyclic diterpenes were found throughout the TCT complex. These compounds were found to have the highest absolute and relative abundance in several temperate rainforest and marsh endemics and the lowest relative abundance in desert adapted species. Large scale phylogenetic patterns in the distribution of individual diterpenes were not evident. Some species showed little intraspecific variation in diterpenes, while others showed considerable variability in diterpene products from one tree to another. The waxes of many members of the TCT complex are dominated by uniquely long-chain normal alkanes, with peak abundance at 33 and/or 35 carbons. This character is found within a phylogenetically distinct group of TCT -- including the genera Austrocedrus, Callitris, Calocedrus, Chamaecyparis, Cryptomeria, Cupressus, Diselma, Fitzroya, Juniperus, Libocedrus, Platycladus, Taxodium, Tetraclinis, Thuja, and Thujopsis -- and is seen in plants from extremely different habitats. We postulate that this group within the TCT complex shares a conserved very long chain fatty acid (VLCFA) elongase

  7. Wax ester profiling of seed oil by nano-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Iven, Tim; Herrfurth, Cornelia; Hornung, Ellen; Heilmann, Mareike; Hofvander, Per; Stymne, Sten; Zhu, Li-Hua; Feussner, Ivo

    2013-07-06

    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. 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. 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 like cuticular lipid extracts to

  8. 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.

  9. 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.

  10. 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

  11. '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.

  12. Production of bacterial cellulose by Gluconacetobacter hansenii CGMCC 3917 using only waste beer yeast as nutrient source.

    Science.gov (United States)

    Lin, Dehui; Lopez-Sanchez, Patricia; Li, Rui; Li, Zhixi

    2014-01-01

    In order to improve the use of waste beer yeast (WBY) for bacterial cellulose production by Gluconacetobacter hansenii CGMCC 3917, a two-step pre-treatment was designed. First WBY was treated by 4 methods: 0.1M NaOH treatment, high speed homogenizer, ultrasonication and microwave treatment followed by hydrolysis (121°C, 20 min) under mild acid condition (pH 2). The optimal pre-treatment conditions were evaluated by the reducing sugar yield after hydrolysis. 15% WBY treated by ultrasonication for 40 min had the highest reducing sugar yield (29.19%), followed by NaOH treatment (28.98%), high speed homogenizer (13.33%) and microwaves (13.01%). Treated WBY hydrolysates were directly supplied as only nutrient source for BC production. A sugar concentration of 3% WBY hydrolysates treated by ultrasonication gave the highest BC yield (7.02 g/L), almost 6 times as that from untreated WBY (1.21 g/L). Furthermore, the properties of the BC were as good as those obtained from the conventional chemical media. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  13. Harnessing the extracellular bacterial production of nanoscale cobalt ferrite with exploitable magnetic properties.

    Science.gov (United States)

    Coker, Victoria S; Telling, Neil D; van der Laan, Gerrit; Pattrick, Richard A D; Pearce, Carolyn I; Arenholz, Elke; Tuna, Floriana; Winpenny, Richard E P; Lloyd, Jonathan R

    2009-07-28

    Nanoscale ferrimagnetic particles have a diverse range of uses from directed cancer therapy and drug delivery systems to magnetic recording media and transducers. Such applications require the production of monodisperse nanoparticles with well-controlled size, composition, and magnetic properties. To fabricate these materials purely using synthetic methods is costly in both environmental and economical terms. However, metal-reducing microorganisms offer an untapped resource to produce these materials. Here, the Fe(III)-reducing bacterium Geobacter sulfurreducens is used to synthesize magnetic iron oxide nanoparticles. A combination of electron microscopy, soft X-ray spectroscopy, and magnetometry techniques was employed to show that this method of biosynthesis results in high yields of crystalline nanoparticles with a narrow size distribution and magnetic properties equal to the best chemically synthesized materials. In particular, it is demonstrated here that cobalt ferrite (CoFe(2)O(4)) nanoparticles with low temperature coercivity approaching 8 kOe and an effective anisotropy constant of ∼10(6) erg cm(-3) can be manufactured through this biotechnological route. The dramatic enhancement in the magnetic properties of the nanoparticles by the introduction of high quantities of Co into the spinel structure represents a significant advance over previous biomineralization studies in this area using magnetotactic bacteria. The successful production of nanoparticulate ferrites achieved in this study at high yields could open up the way for the scaled-up industrial manufacture of nanoparticles using environmentally benign methodologies.

  14. 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

  15. Bacterial Keratitis

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Bacterial Keratitis Sections What Is Bacterial Keratitis? Bacterial Keratitis Symptoms ... Lens Care Bacterial Keratitis Treatment What Is Bacterial Keratitis? Leer en Español: ¿Qué Es la Queratitis Bacteriana? ...

  16. Staphylococcus aureus Infection of Human Gestational Membranes Induces Bacterial Biofilm Formation and Host Production of Cytokines.

    Science.gov (United States)

    Doster, Ryan S; Kirk, Leslie A; Tetz, Lauren M; Rogers, Lisa M; Aronoff, David M; Gaddy, Jennifer A

    2017-02-15

    Staphylococcus aureus, a metabolically flexible gram-positive pathogen, causes infections in a variety of tissues. Recent evidence implicates S. aureus as an emerging cause of chorioamnionitis and premature rupture of membranes, which are associated with preterm birth and neonatal disease. We demonstrate here that S. aureus infects and forms biofilms on the choriodecidual surface of explanted human gestational membranes. Concomitantly, S. aureus elicits the production of proinflammatory cytokines, which could ultimately perturb maternal-fetal tolerance during pregnancy. Therefore, targeting the immunological response to S. aureus infection during pregnancy could attenuate disease among infected individuals, especially in the context of antibiotic resistance. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  17. 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)

  18. 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

  19. Hydrogen isotope fractionation in leaf waxes in the Alaskan Arctic tundra

    Science.gov (United States)

    Daniels, William C.; Russell, James M.; Giblin, Anne E.; Welker, Jeffrey M.; Klein, Eric S.; Huang, Yongsong

    2017-09-01

    Leaf wax hydrogen isotopes (δDwax) are increasingly utilized in terrestrial paleoclimate research. Applications of this proxy must be grounded by studies of the modern controls on δDwax, including the ecophysiological controls on isotope fractionation at both the plant and landscape scales. Several calibration studies suggest a considerably smaller apparent fractionation between source water and waxes (εapp) at high latitudes relative to temperate or tropical locations, with major implications for paleoclimatic interpretations of sedimentary δDwax. Here we investigate apparent fractionation in the Arctic by tracing the isotopic composition of leaf waxes from production in modern plants to deposition in lake sediments using isotopic observations of precipitation, soil and plant waters, living leaf waxes, and waxes in sediment traps in the Brooks Range foothills of northern Alaska. We also analyze a lake surface sediment transect to compare present-day vegetation assemblages to εapp at the watershed scale. Source water and εapp were determined for live specimens of Eriophorum vaginatum (cottongrass) and Betula nana (dwarf birch), two dominant tundra plants in the Brooks Range foothills. The δD of these plants' xylem water closely tracks that of surface soil water, and reflects a summer-biased precipitation source. Leaf water is enriched by 23 ± 15‰ relative to xylem water for E. vaginatum and by 41 ± 19‰ for B. nana. Evapotranspiration modeling indicates that this leaf water enrichment is consistent with the evaporative enrichment expected under the climate conditions of northern Alaska, and that 24-h photosynthesis does not cause excessive leaf water isotope enrichment. The εapp determined for our study species average -89 ± 14‰ and -106 ± 16‰ for B. nana n-alkanes and n-acids, respectively, and -182 ± 10‰ and -154 ± 26‰ for E. vaginatum n-alkanes and n-acids, which are similar to the εapp of related species in temperate and tropical

  20. 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

  1. 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

  2. Harvesting microalgae using activated sludge can decrease polymer dosing and enhance methane production via co-digestion in a bacterial-microalgal process

    DEFF Research Database (Denmark)

    Wágner, Dorottya Sarolta; Radovici, Maria; Smets, Barth F.

    2016-01-01

    Third generation biofuels, e.g. biofuels production from algal biomass, have gained attention due to increased interest on global renewable energy. However, crop-based biofuels compete with food production and should be avoided. Microalgal cultivation for biofuel production offers an alternative...... to crops and can become economically viable when combined with the use of used water resources. Besides nutrients and water, harvesting microalgal biomass represents one of the major costs related to biofuel production and thus efficient and cheap solutions are needed. In bacterial-algal systems......, there is the potential to produce energy by co-digesting the two types of biomass. We present an innovative approach to recover microalgal biomass via a two-step flocculation using bacterial biomass after the destabilisation of microalgae with conventional cationic polymer. A short solids retention time (SRT) enhanced...

  3. Polyethylene bio-degradation by caterpillars of the wax moth Galleria mellonella.

    Science.gov (United States)

    Bombelli, Paolo; Howe, Christopher J; Bertocchini, Federica

    2017-04-24

    Plastics are synthetic polymers derived from fossil oil and largely resistant to biodegradation. Polyethylene (PE) and polypropylene (PP) represent ∼92% of total plastic production. PE is largely utilized in packaging, representing ∼40% of total demand for plastic products (www.plasticseurope.org) with over a trillion plastic bags used every year [1]. Plastic production has increased exponentially in the past 50 years (Figure S1A in Supplemental Information, published with this article online). In the 27 EU countries plus Norway and Switzerland up to 38% of plastic is discarded in landfills, with the rest utilized for recycling (26%) and energy recovery (36%) via combustion (www.plasticseurope.org), carrying a heavy environmental impact. Therefore, new solutions for plastic degradation are urgently needed. We report the fast bio-degradation of PE by larvae of the wax moth Galleria mellonella, producing ethylene glycol. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. A strategy for bacterial production of a soluble functional human neonatal Fc receptor

    DEFF Research Database (Denmark)

    Andersen, Jan Terje; Justesen, Sune; Berntzen, Gøril

    2008-01-01

    (human) or newborn (rodents), and may translocate IgG over mucosal surfaces. FcRn interacts with the Fc-region of IgG and domain III of albumin with binding at pH 6.0 and release at pH 7.4. Knowledge of these interactions has facilitated design of recombinant proteins with altered serum half-lives and....../or altered biodistribution. To generate further research in this field, there is a great need for large amounts of soluble human FcRn (shFcRn) for in vitro interaction studies. In this report, we describe a novel laboratory scale production of functional shFcRn in Escherichia coli (E. coli) at milligram...... correctly formed as demonstrated by circular dichroism (CD). Furthermore, functional and stringent pH dependent binding to IgG and human serum albumin were demonstrated by ELISA and surface plasmon resonance (SPR). This method may be easily adapted for the expression of large amounts of other FcRn species...

  5. The Unique Role of the ECERIFERUM2-LIKE Clade of the BAHD Acyltransferase Superfamily in Cuticular Wax Metabolism.

    Science.gov (United States)

    Haslam, Tegan M; Gerelle, Wesley K; Graham, Sean W; Kunst, Ljerka

    2017-06-13

    The elongation of very-long-chain fatty acids is a conserved process used for the production of many metabolites, including plant cuticular waxes. The elongation of precursors of the most abundant cuticular wax components of some plants, however, is unique in requiring ECERIFERUM2-LIKE (CER2-LIKE) proteins. CER2-LIKEs are a clade within the BAHD superfamily of acyltransferases. They are known to be required for cuticular wax production in both Arabidopsis and maize based on mutant studies. Heterologous expression of Arabidopsis and rice CER2-LIKEs in Saccharomyces cerevisiae has demonstrated that they modify the chain-length specificity of elongation when paired with particular condensing enzymes. Despite sequence homology, CER2-LIKEs are distinct from the BAHD superfamily in that they do not appear to use acyl transfer activity to fulfill their biological function. Here, we review the discovery and characterization of CER2-LIKEs, propose several models to explain their function, and explore the importance of CER2-LIKE proteins for the evolution of plant cuticles.

  6. The Unique Role of the ECERIFERUM2-LIKE Clade of the BAHD Acyltransferase Superfamily in Cuticular Wax Metabolism

    Directory of Open Access Journals (Sweden)

    Tegan M. Haslam

    2017-06-01

    Full Text Available The elongation of very-long-chain fatty acids is a conserved process used for the production of many metabolites, including plant cuticular waxes. The elongation of precursors of the most abundant cuticular wax components of some plants, however, is unique in requiring ECERIFERUM2-LIKE (CER2-LIKE proteins. CER2-LIKEs are a clade within the BAHD superfamily of acyltransferases. They are known to be required for cuticular wax production in both Arabidopsis and maize based on mutant studies. Heterologous expression of Arabidopsis and rice CER2-LIKEs in Saccharomyces cerevisiae has demonstrated that they modify the chain-length specificity of elongation when paired with particular condensing enzymes. Despite sequence homology, CER2-LIKEs are distinct from the BAHD superfamily in that they do not appear to use acyl transfer activity to fulfill their biological function. Here, we review the discovery and characterization of CER2-LIKEs, propose several models to explain their function, and explore the importance of CER2-LIKE proteins for the evolution of plant cuticles.

  7. Single-step production of a recyclable nanobiocatalyst for organophosphate pesticides biodegradation using functionalized bacterial magnetosomes.

    Directory of Open Access Journals (Sweden)

    Nicolas Ginet

    Full Text Available Enzymes are versatile catalysts in laboratories and on an industrial scale; improving their immobilization would be beneficial to broadening their applicability and ensuring their (reuse. Lipid-coated nano-magnets produced by magnetotactic bacteria are suitable for a universally applicable single-step method of enzyme immobilization. By genetically functionalizing the membrane surrounding these magnetite particles with a phosphohydrolase, we engineered an easy-to-purify, robust and recyclable biocatalyst to degrade ethyl-paraoxon, a commonly used pesticide. For this, we genetically fused the opd gene from Flavobacterium sp. ATCC 27551 encoding a paraoxonase to mamC, an abundant protein of the magnetosome membrane in Magnetospirillum magneticum AMB-1. The MamC protein acts as an anchor for the paraoxonase to the magnetosome surface, thus producing magnetic nanoparticles displaying phosphohydrolase activity. Magnetosomes functionalized with Opd were easily recovered from genetically modified AMB-1 cells: after cellular disruption with a French press, the magnetic nanoparticles are purified using a commercially available magnetic separation system. The catalytic properties of the immobilized Opd were measured on ethyl-paraoxon hydrolysis: they are comparable with the purified enzyme, with K(m (and k(cat values of 58 µM (and 178 s(-1 and 43 µM (and 314 s(-1 for the immobilized and purified enzyme respectively. The Opd, a metalloenzyme requiring a zinc cofactor, is thus properly matured in AMB-1. The recycling of the functionalized magnetosomes was investigated and their catalytic activity proved to be stable over repeated use for pesticide degradation. In this study, we demonstrate the easy production of functionalized magnetic nanoparticles with suitably genetically modified magnetotactic bacteria that are efficient as a reusable nanobiocatalyst for pesticides bioremediation in contaminated effluents.

  8. 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.

  9. 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)

  10. 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

  11. 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

  12. Effect of Single Bacterial Starter Culture on Odour Reduction During Controlled Fermentation of Cassava Tubers for Foofoo Production

    Directory of Open Access Journals (Sweden)

    Henshaw, E. E.

    2010-01-01

    Full Text Available Effects of single bacterial starter culture on odour reduction during controlled fermentation of cassava tubers for foofoo production were investigated. Pure cultures were used to ferment cassava tubers in water for 96 h. The cultures used include Bacillus subtilis, Klebsiela sp., Lactobacillus plantarum and Leuconostoc mesenteroides. L. plantarum exhibited the highest acid producing ability, decreasing the pH of the Cassava tubers from 6.2 to 3.68 with a corresponding increase in total titratable acidity (TTA from 0.082% to 0.290% during the 96 h fermentation period. The effected changes in pH and TTA by other organisms ranged respectively from 4.88 and 0.135% for Klebsiella sp., 4.68 and 0.136% for L. mesenteroides to 4.90 and 0.139% for B. subtilis with in the period. All the cultures were found to contribute in varying degree to odour reduction in fermented cassava; B. subtilis effected the highest odour reduction followed by L. plantarum.

  13. Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications

    Science.gov (United States)

    Biresaw, Girma; Gordon, Sherald

    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. PMID:29484216

  14. The effect of wax coating, aluminum and ammonium perchlorate on impact sensitivity of HMX

    Directory of Open Access Journals (Sweden)

    Yu-bin LI

    2017-12-01

    Full Text Available Interaction of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX/ammonium perchlorate (AP and its effect on mechanical sensitivity may result in some restrictions for the application of AP/HMX system in high energetic weapon system. In this work, impact sensitivity test is used to study the effects of wax coating of HMX, AP and aluminum (Al powder on sensitivity properties of HMX/AP/Al mixtures. Thermogravimetry-differential scanning calorimetry (TG-DSC analysis has been developed to investigate the mechanism of interaction between HMX and AP during the course of thermal decomposition of HMX/AP/Al mixtures. The results show that severe interaction effect exists between AP and HMX, which causes the impact sensitivity (H50 to become smaller. The impact energy (E50 of mixture can be improved under the circumstances of effective separating HMX from AP by surface coating with Wax. AP may firstly engender low-temperature decomposition under the circumstance of external heat or mechanical impact, which causes the exothermic peak of HMX forward shift about 28 °C. The gaseous product releasing from thermal decomposition of HMX accelerates further decomposition of AP. For HMX/AP composite system, the interactive catalysis effect between AP and HMX can be eliminated mostly by adding a great deal of Al powder (i.e. above 30%.

  15. 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.

  16. The texture, sensory properties and stability of cookies prepared with wax oleogels.

    Science.gov (United States)

    Yılmaz, Emin; Öğütcü, Mustafa

    2015-04-01

    Shortening is the essential component of high quality baked foods. Its effects on dough structure formation and the desired final product attributes depend mostly on its solid fat content and β' crystalline polymorphs. Saturated and trans fatty acids present in shortening pose some important negative health considerations. Hence, alternative plastic fats with lower or zero quantity of saturated and trans fatty acids are in high demand. Oleogels are gel networks of liquid edible oils with no trans and very low saturated fatty acids. In this study, sunflower wax (SW) and beeswax (BW) oleogels of hazelnut oil were used in cookie preparation against commercial bakery shortening (CBS) as the control, to compare the textural, sensory and stability properties of the cookies. The basic chemical composition, textural properties, and some physical attributes of the cookies were compared. Sensory texture/flavor profile analysis (T/FPA) and consumer hedonic tests were also accomplished. Furthermore, the changes in cookie texture and stability were monitored during 30 day storage at room temperature. It was found out that in almost all properties, the oleogel cookies resembled CBS cookies. T/FPA results present detailed data for literature. Consumer hedonic scores indicated that oleogel cookies were better than CBS cookies and were also well accepted by consumers. Wax oleogels can be used as cookie shortening successfully.

  17. 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.

  18. 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

  19. Ultrasound assisted manufacturing of paraffin wax nanoemulsions: process optimization.

    Science.gov (United States)

    Jadhav, A J; Holkar, C R; Karekar, S E; Pinjari, D V; Pandit, A B

    2015-03-01

    This work reports on the process optimization of ultrasound-assisted, paraffin wax in water nanoemulsions, stabilized by modified sodium dodecyl sulfate (SDS). This work focuses on the optimization of major emulsification process variables including sonication time, applied power and surfactant concentration. The effects of these variables were investigated on the basis of mean droplet diameter and stability of the prepared emulsion. It was found that the stable emulsion with droplet diameters about 160.9 nm could be formed with the surfactant concentration of 10 mg/ml and treated at 40% of applied power (power density: 0.61 W/ml) for 15 min. Scanning electron microscopy (SEM) was used to study the morphology of the emulsion droplets. The droplets were solid at room temperature, showing bright spots under polarized light and a spherical shape under SEM. The electrophoretic properties of emulsion droplets showed a negative zeta potential due to the adsorption of head sulfate groups of the SDS surfactant. For the sake of comparison, paraffin wax emulsion was prepared via emulsion inversion point method and was checked its intrinsic stability. Visually, it was found that the emulsion get separated/creamed within 30 min. while the emulsion prepared via ultrasonically is stable for more than 3 months. From this study, it was found that the ultrasound-assisted emulsification process could be successfully used for the preparation of stable paraffin wax nanoemulsions.

  20. Wax removal for accelerated cotton scouring with alkaline pectinase.

    Science.gov (United States)

    Agrawal, Pramod B; Nierstrasz, Vincent A; Klug-Santner, Barbara G; Gübitz, Georg M; Lenting, Herman B M; Warmoeskerken, Marijn M C G

    2007-03-01

    A rational approach has been applied to design a new environmentally acceptable and industrially viable enzymatic scouring process. Owing to the substrate specificity, the selection of enzymes depends on the structure and composition of the substrate, i.e. cotton fibre. The structure and composition of the outer layers of cotton fibre has been established on the basis of thorough literature study, which identifies wax and pectin removal to be the key steps for successful scouring process. Three main issues are discussed here, i.e. benchmarking of the existing alkaline scouring process, an evaluation of several selected acidic and alkaline pectinases for scouring, and the effect of wax removal treatment on pectinase performance. It has been found that the pectinolytic capability of alkaline pectinases on cotton pectin is nearly 75% higher than that of acidic pectinases. It is concluded that an efficient wax removal prior to pectinase treatment indeed results in improved performance in terms of hydrophilicity and pectin removal. To evaluate the hydrophilicity, the structural contact angle (theta) was measured using an auto-porosimeter.

  1. 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.

  2. 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

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

    Science.gov (United States)

    Belila, A; El-Chakhtoura, J; Otaibi, N; Muyzer, G; Gonzalez-Gil, G; Saikaly, P E; van Loosdrecht, M C M; Vrouwenvelder, J S

    2016-05-01

    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 m(3)/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

  4. Significant alteration of soil bacterial communities and organic carbon decomposition by different long-term fertilization management conditions of extremely low-productivity arable soil in South China.

    Science.gov (United States)

    Xun, Weibing; Zhao, Jun; Xue, Chao; Zhang, Guishan; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-06-01

    Different fertilization managements of red soil, a kind of Ferralic Cambisol, strongly affected the soil properties and associated microbial communities. The association of the soil microbial community and functionality with long-term fertilization management in the unique low-productivity red soil ecosystem is important for both soil microbial ecology and agricultural production. Here, 454 pyrosequencing analysis of 16S recombinant ribonucleic acid genes and GeoChip4-NimbleGen-based functional gene analysis were used to study the soil bacterial community composition and functional genes involved in soil organic carbon degradation. Long-term nitrogen-containing chemical fertilization-induced soil acidification and fertility decline and significantly altered the soil bacterial community, whereas long-term organic fertilization and fallow management improved the soil quality and maintained the bacterial diversity. Short-term quicklime remediation of the acidified soils did not change the bacterial communities. Organic fertilization and fallow management supported eutrophic ecosystems, in which copiotrophic taxa increased in relative abundance and have a higher intensity of labile-C-degrading genes. However, long-term nitrogen-containing chemical fertilization treatments supported oligotrophic ecosystems, in which oligotrophic taxa increased in relative abundance and have a higher intensity of recalcitrant-C-degrading genes but a lower intensity of labile-C-degrading genes. Quicklime application increased the relative abundance of copiotrophic taxa and crop production, although these effects were utterly inadequate. This study provides insights into the interaction of soil bacterial communities, soil functionality and long-term fertilization management in the red soil ecosystem; these insights are important for improving the fertility of unique low-productivity red soil. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  5. Adhesion force measurements on the two wax layers of the waxy zone in Nepenthes alata pitchers.

    Science.gov (United States)

    Gorb, Elena V; Purtov, Julia; Gorb, Stanislav N

    2014-06-03

    The wax coverage of the waxy zone in Nepenthes alata pitchers consists of two clearly distinguishable layers, designated the upper and lower wax layers. Since these layers were reported to reduce insect attachment, they were considered to have anti-adhesive properties. However, no reliable adhesion tests have been performed with these wax layers. In this study, pull-off force measurements were carried out on both wax layers of the N. alata pitcher and on two reference polymer surfaces using deformable polydimethylsiloxane half-spheres as probes. To explain the results obtained, roughness measurements were performed on test surfaces. Micro-morphology of both surface samples and probes tested was examined before and after experiments. Pull-off forces measured on the upper wax layer were the lowest among surfaces tested. Here, contamination of probes by wax crystals detached from the pitcher surface was found. This suggests that low insect attachment on the upper wax layer is caused primarily by the breaking off of wax crystals from the upper wax layer, which acts as a separation layer between the insect pad and the pitcher surface. High adhesion forces obtained on the lower wax layer are explained by the high deformability of probes and the particular roughness of the substrate.

  6. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

    Science.gov (United States)

    Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

    2017-04-01

    Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion.

  7. 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.

  8. 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

  9. 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, Pdie material factor both on the marginal adaptation (F=503.47, Pdies 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 between the marginal accuracy and the contact angle values. As the contact angle value became smaller, the marginal accuracy improved. All combinations of waxes and stone and titanium dies presented a high wettability. Copyright © 2014 Editorial Council for the Journal of Prosthetic

  10. 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.

  11. 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)

    Hao, Suxiao; Ma, Yiyi; Zhao, Shuang; Ji, Qianlong; Zhang, Kezhong; Yang, Mingfeng; Yao, Yuncong

    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.

  12. McWRI1, a transcription factor of the AP2/SHEN family, regulates the biosynthesis of the cuticular waxes on the apple fruit surface under low temperature.

    Directory of Open Access Journals (Sweden)

    Suxiao Hao

    Full Text Available 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.

  13. Use of AmpliWax to optimize amplicon sterilization by isopsoralen.

    Science.gov (United States)

    De la Viuda, M; Fille, M; Ruiz, J; Aslanzadeh, J

    1996-12-01

    The photochemical inactivation of amplicons by isopsoralen (IP-10) has been suggested as a possible means to prevent PCR carryover contamination. To evaluate the technique, serial dilutions of amplicons (10(11) to 10(3)) from the Borrelia burgdorferi OSP A gene were amplified in the presence of 0, 25, 50, and 100 micrograms of IP-10 per ml for 45 cycles. The PCR products were exposed to UV light for 15 min to activate IP-10 and sterilize the amplicons. One microliter of each sterilized sample was reamplified for an additional 45 cycles. The PCR products were then resolved in an agarose gel, blotted onto a nylon membrane, and probed with an alkaline phosphatase-conjugated chemiluminescent probe. Although IP-10 at concentrations of 50 and 100 micrograms/ml effectively sterilized up to 10(11) amplicons, the compound was inhibitory to PCR. IP-10 at a concentration of 25 micrograms/ml had slight inhibitory effect on PCR and did not completely sterilized all of the amplicons. Therefore, in subsequent experiments AmpliWax was substituted for mineral oil, and PCR was performed on 10(9) to 10(3) amplicons as described above. Following the amplification, the PCR tubes were cooled to solidify the AmpliWax and inoculated with various concentrations of IP-10. With this technique, PCR products produced from as many as 10(9) target amplicons were effectively sterilized with 200 micrograms of IP-10 per ml. Similarly, the addition of IP-10 (50 micrograms/ml) before and after PCR was evaluated for the detection of B. burgdorferi in 62 ticks from a region of Southern Connecticut where the organism is highly endemic. PCR performed in the presence of 50 micrograms of IP-10 per ml detected B. burgdorferi-specific DNA in 17 of 62 ticks (27%) following gel electrophoresis and in 34 of 62 ticks (55%) following Southern blot hybridization of the PCR products. In contrast, post-PCR addition of IP-10 detected borrelia-specific DNA in 31 of 62 ticks (50%) following gel electrophoresis and in

  14. 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

  15. Real-Time PCR Detection ofBurkholderia cepaciain Pharmaceutical Products Contaminated with Low Levels of Bacterial Contamination.

    Science.gov (United States)

    Jimenez, Luis; Jashari, Theranda; Vasquez, Jenifer; Zapata, Stephanie; Bochis, Joy; Kulko, Margarita; Ellman, Victoria; Gardner, Matthew; Choe, Tina

    2018-01-01

    A real-time polymerase chain reaction (RT-PCR) assay was developed to detect Burkholderia cepacia in pharmaceutical products contaminated with low levels of bacteria. Different pharmaceutical suspensions were artificially contaminated with B. cepacia , Escherichia coli , Staphylococcus aureus , and Bacillus megaterium After a 24 h incubation in trypticase soy broth with Tween 20, samples were streaked on mannitol salt, phenyl ethyl alcohol, eosin methylene blue, MacConkey, and pseudomonas isolation agar. Microbial DNA was extracted from each sample by using a Tris-EDTA, proteinase K, Tween 20 buffer. Regular PCR targeting the 1.5 kilobases 16S rRNA eubacterial gene and cloning showed the predominant DNA in the extracted mix belonged to E. coli Selective media isolation of bacterial contamination showed B. cepacia only detected on pseudomonas isolation while eosin methylene blue and MacConkey detected only E. coli RT-PCR using primers PSL1 and PSR1 amplified a 209 bp 16S rRNA fragment using a Roche LightCycler 96 ® system with SYBR green I, a common double-stranded binding dye. The cycle at which fluorescence from amplification exceeds the background fluorescence was referred to as quantification cycle. All samples were found to be positive by standard microbiological testing and RT-PCR. B. cepacia was detected within 30 h in all contaminated samples using RT-PCR. Based upon standard curve analysis of B. cepacia DNA, the minimum DNA concentration that could be detected was 10 fg/uL with a correlation value of 0.98. RT-PCR detection of B. cepacia allowed faster quality control analysis, corrective actions, and process optimization. LAY ABSTRACT: A real-time polymerase chain reaction (RT-PCR) assay was developed to detect Burkholderia cepacia in pharmaceutical products contaminated with low levels of bacteria. B. cepacia is the number one reason for microbial contamination recalls of non-sterile drug products in the USA. RT-PCR using primers PSL1 and PSR1 amplified a

  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. 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.

  18. 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.

  19. Development of non-destructive methods for the determination of airborne pollutants in pine needles: identification of trace constituents in radiata pine epicuticular wax

    Energy Technology Data Exchange (ETDEWEB)

    Franich, R.A. (Wood Products Div., New Zealand Forest Research Inst. Ltd., Rotorua (New Zealand)); Jakobsson, E. (Environmental Chemistry, Wallenberg Lab., Stockholm Univ. (Sweden)); Jensen, S. (Environmental Chemistry, Wallenberg Lab., Stockholm Univ. (Sweden)); Kroese, H.W. (Wood Products Div., New Zealand Forest Research Inst. Ltd., Rotorua (New Zealand)); Kylin, H. (Environmental Chemistry, Wallenberg Lab., Stockholm Univ. (Sweden) Dept. of Analytical Chemistry, Arrhenius Lab., Stockholm Univ. (Sweden))

    1993-01-01

    In an attempt to develop non-destructive work-up procedures for monitoring lipophilic pollutants in the air by analysis of pine needle epicuticular wax, a project was undertaken to identify substances that interfere with the normal gas-chromatographic quantitations. Epicuticular wax was extracted from needles of radiata pine and processed to remove the bulk estolides and resin and fatty acids. Fractionation of the residue on a silica gel column gave three fractions, representing less than 0.2% of the wax. The fractions contained a mixture of natural products and anthropogenic chemicals. Among the natural products were sesquiterpenes, comprising mainly amorphene, cadinenes, germacrene and cadalene; bisnor-, nor- and diterpene hydrocarbons; methyl esters of resin acids; and 9,10-secodehydroabietanes of unknown ring-A structure. Some of these compounds have not been reported from pine needle epicuticular wax previously. Anthropogenic chemicals identified include polycyclic aromatic hydrocarbons. The organochlorine compounds of environmental importance were hexachlorocyclohexanes (including lindane), hexachlorobenzene, pentachloroanisole, chlordanes, dieldrin, p,p'-DDE, p,p'-DDT, and penta-, hexa- and heptachlorobiphenyls. (orig./BBR)

  20. The use of paraffin wax in a new solar cooker with inner and outer reflectors

    OpenAIRE

    Arabacigil Bihter; Yuksel Numan; Avci Atakan

    2015-01-01

    In this paper, the potential use and effectiveness of paraffin wax in a new solar cooker was experimentally investigated during daylight and late evening hours. For these experiments, a cooker having an inner reflecting surface was designed, constructed by filling paraffin wax and metal shavings. The side- and sub-surface temperatures of the paraffin wax in the cooker are measured in the summer months of June and July. The thermal efficiency of the cooker w...

  1. 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)

  2. Biosynthesis of lead epicuticular waxes as influenced by herbicides in two semiarid shrubs

    International Nuclear Information System (INIS)

    Rao, J.V.S.; Reddy, K.R.; Devi, M.S.

    1986-01-01

    The influence of paraquat and 2,4,5-T at 100 and 2000 mg 1 -1 on the levels of leaf surface wax, cuticle, cuticular transpiration and wax biosynthesis was studied in two semiarid shrubs. The herbicides significantly decreased the leaf surface wax, and resulted in increased cuticular transpiration which was associated with increased synthesis of fatty acids and decrease in aldehyde, alcohol and hydrocarbon fractions as evidenced from acetate-1- 14 C studies. (author)

  3. 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.

  4. 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.

  5. Development and regeneration ability of the wax coverage in Nepenthes alata pitchers: a cryo-SEM approach.

    Science.gov (United States)

    Gorb, Elena V; Baum, Martina J; Gorb, Stanislav N

    2013-10-29

    The morphogenesis of the composite epicuticular wax coverage and regeneration ability of the upper wax layer in Nepenthes alata pitchers were studied using a cryo-scanning electron microscopy. Examination of pitchers of different ages revealed six stages in the wax coverage development. In the first stage, wax crystals resemble those found recently in mature pitches of N. dicksoniana and N. ventricosa. Platelets of the upper wax layer originate from broadened tips of stalks during the last developmental stage. Contrary to previous hypotheses, we found that wax crystals of both layers as well as the stalks connecting them are oriented perpendicularly to the pitcher wall. No changes in the height of the wax coverage were detected in 4-8 weeks after mechanical removal of the upper wax layer from mature pitchers on plants. This indicates that the wax coverage in N. alata pitchers is unable to regenerate.

  6. 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.

  7. The evolution of anatomical illustration and wax modelling in Italy from the 16th to early 19th centuries

    Science.gov (United States)

    Riva, Alessandro; Conti, Gabriele; Solinas, Paola; Loy, Francesco

    2010-01-01

    Although the contribution to anatomical illustration by Vesalius and his followers has received much attention, less credit has been given to Veslingius and particularly Fabricius. By 1600, Fabricius had amassed more than 300 paintings that together made the Tabulae Pictae, a great atlas of anatomy that was highly admired by his contemporaries. Many of his new observations were incorporated into subsequent books, including those by Casserius, Spighelius, Harvey and Veslingius. Also of importance were the Tabulae by Eustachius (1552), which, although only published in 1714, greatly influenced anatomical wax modelling. In 1742, Pope Benedict XIV established a Museum of Anatomy in Bologna, entrusting to Ercole Lelli the creation of several anatomical preparations in wax. Felice Fontana realised that the production of a large number of models by the casting method would make cadaveric specimens superfluous for anatomical teaching and in 1771 he asked the Grand Duke to fund a wax-modelling workshop in Florence as part of the Natural History Museum, later known as La Specola. Fontana engaged Giuseppe Ferrini as his first modeller and then the 19-year-old Clemente Susini who, by his death in 1814, had superintended the production of, or personally made, more than 2000 models. In 1780, the Austrian Emperor Joseph II visited La Specola and ordered a great number of models for his Josephinum museum; these were made by Fontana with the help of Clemente Susini and supervised by the anatomist Paolo Mascagni. It is, however, in Cagliari that some of Susini’s greatest waxes are to be found. These were made when he was free of Fontana’s influence and were based on dissections made by Francesco Antonio Boi (University of Cagliari). Their distinctive anatomical features include the emphasis given to nerves and the absence of lymphatics in the brain, a mistake made on earlier waxes. The refined technical perfection of the anatomical details demonstrates the closeness of the

  8. THE RÔLE OF THE "WAX" OF THE TUBERCLE BACILLUS IN ESTABLISHING DELAYED HYPERSENSITIVITY

    Science.gov (United States)

    Raffel, Sidney; Arnaud, Louis E.; Dukes, C. Dean; Huang, Jwo S.

    1949-01-01

    Guinea pigs sensitized with egg albumin along with the purified wax fraction of the human tubercle bacillus respond with delayed hypersensitive reactivity to the protein antigen. Previous publications have reported a similar activity of the wax with respect to tuberculoprotein and picryl chloride. The effect is not referable to an ordinary adjuvant activity of the bacillary wax, since antibody titers are not increased in animals which receive it, and since a known adjuvant, water-in-oil emulsion, has no effect with respect to the induction of delayed hypersensitivity. This report further extends the rôle of the tubercle bacillary wax in the induction of delayed hypersensitive states. PMID:18152339

  9. 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.

  10. Bacterial biodiversity in deep-sea sediments from two regions of contrasting surface water productivity near the Crozet Islands, Southern Ocean

    Science.gov (United States)

    Jamieson, R. E.; Heywood, J. L.; Rogers, A. D.; Billett, D. S. M.; Pearce, D. A.

    2013-05-01

    The relationship between surface-derived particulate organic matter (POM) and deep-sea sediment bacterial abundance, community structure and composition was investigated in two different sediment layers from two zones of contrasting surface water productivity in the southern Indian Ocean. Bacterial sediment communities from high chlorophyll (HC) and low chlorophyll (LC) sites were characterized and compared using direct counts, clone library construction, denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH). Of the 1566 bacterial clones generated from the sediment communities, 1010 matched published 16S rDNA sequences at ≥97% identity. A comparison of surface sediment clone libraries showed that at least one third of all identified operational taxonomic units (OTUs) were common to both HC and LC sites. DGGE community profiles were consistent (82% similar) and evenness of the major phylogenetic groups was 96% similar between surface sediment communities, where gamma- and alpha-Proteobacteria were dominant. Sediment communities shared similarly high biodiversity, while species richness was marginally higher at the LC site. Intra-site shifts in bacterial abundance and composition were observed with increasing sediment depth. Despite the differences in organic matter input between sites, the consistency observed between HC and LC sediment communities pointed to (1) the extent of remineralisation by mega and meio-fauna as a potential factor affecting the quantity and quality of POM available to sediment bacteria, (2) sampling during the early 'nutrient assimilation phase' of the bacterial response to freshly deposited POM or (3) that the action of bacteria in the water column could affect the quantity and quality of POM available to sediment bacteria. Although factors other than these may explain the observed similarities, this first comparison of such deep-sea sediment communities in relation to surface-derived productivity may

  11. 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

  12. 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

  13. Retrospective observational study to investigate Sinerga, a multifactorial nutritional product, and bacterial extracts in the prevention of recurrent respiratory infections in children.

    Science.gov (United States)

    Nigro, A; Nicastro, A; Trodella, R

    2014-01-01

    In this retrospective observational clinical study, 167 children, aged 3 to 7 years, of both sexes, with a clinical history of recurrent respiratory infections, administered with bacterial extracts of first and second generation or Sinerga a nutritional product containing palmitoylethanolamide, bovine colostrum, phenylethylamine and the new generation of probiotic kluyveromyces FM B0399, were observed. The goal of the study was to compare the supplementation with Sinerga with the supplementation with bacterial extracts, for the effect on the frequency of episodes of respiratory infection that had resulted in a prescription for antibiotics. The study focused retrospectively on the months from March 2013 to November 2012. The results showed a greater reduction in the frequency of respiratory infections with antibiotic therapy in the group of children supplemented with Sinerga than in the group treated with bacterial extracts. In particular, it was observed that 49.3% of the children supplemented with Sinerga, against 5% of those supplemented with extracts, had no infectious episodes requiring the administration of an antibiotic. 100% of subjects supplemented with Sinerga have had no more than two episodes of respiratory infection, while this condition, in the cohort treated with bacterial extracts, was observed in only 51% of cases.

  14. RDX/Polyethylene Wax Compositions as Pressed Explosive,

    Science.gov (United States)

    1978-09-01

    method may be described generally as cream coloured , free—flowing granular powders. How- ever the powders vary somewhat in appearance with the amount...granules, and are more yellow in colour . Various RDX/polyethylene wax compositions and, for comparison , RDX Grade 1A were examined using a binocular...Report KAR89. Confidential. 5. Dixon, W.J. and Mood , A.M. (1948) . J. Am. statis. Ass., 43, 109 . 6. Cachia, G.P. and Whitbread, E.G. (1958). Proc. R

  15. 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.

  16. 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.

  17. 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.

  18. Properties of Cookies Made with Natural Wax-Vegetable Oil Organogels.

    Science.gov (United States)

    Hwang, Hong-Sik; Singh, Mukti; Lee, Suyong

    2016-05-01

    The aim of this study was to examine the feasibility of cookies in which the conventional margarine is replaced with an organogel of vegetable oil (VO) and natural wax. New cookies from VO organogels contain no trans fats and much less saturated fats than cookies made with a conventional margarine. To understand the effects of different kinds of waxes, organogels were prepared from 4 different waxes including sunflower wax (SW), rice bran wax (RBW), beeswax, and candelilla wax and properties of cookie dough and cookie were evaluated. To investigate the effects of different VOs on the properties of cookies, 3 VOs including olive oil, soybean oil and flaxseed oil representing oils rich in oleic acid (18:1), linoleic acid (18:2), and linolenic acid (18:3), respectively, were used. Both the wax and VO significantly affected properties of organogel such as firmness and melting behavior shown in differential scanning calorimetry. The highest firmness of organogel was observed with SW and flaxseed oil. Properties of dough such as hardness and melting behavior were also significantly affected by wax and VO while trends were somewhat different from those for organogels. SW and RBW provided greatest hardnesses to cookie dough. However, hardness, spread factor, and fracturability of cookie containing the wax-VO organogel were not significantly affected by different waxes and VOs. Several cookies made with wax-VO organogels showed similar properties to cookies made with a commercial margarine. Therefore, this study shows the high feasibility of utilization of the organogel technology in real foods such as cookies rich in unsaturated fats. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  19. 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

  20. Raised Proinflammatory Cytokine Production Within Cerebrospinal Fluid Precedes Fever Onset in Patients With Neurosurgery-Associated Bacterial Meningitis.

    Science.gov (United States)

    Liu, Zhuo-Hao; Tu, Po-Hsun; Chen, Nan-Yu; Yip, Ping K; Bowes, Amy L; Lee, Cheng-Chi; Chan, She-Hung; Kung, Chua-Chi; Wang, Alvin Yi-Chou; Wu, Chieh-Tsai; Lee, Shih-Tseng

    2015-11-01

    The objective of the present study was to determine whether selective inflammatory cytokine concentrations within cerebrospinal fluid are useful markers for the differential diagnosis of aseptic and bacterial meningitis within neurosurgical patients. Prospective, open-label, observational, cohort study. Neurosurgical ICU, Chang Gung Memorial Hospital. Thirty-two consecutive neurosurgical patients who had postoperative fever following external ventricular drain insertion for the treatment of brain injury underwent serial cerebrospinal fluid cytokine analysis pre and post fever to determine the value of such markers in ascertaining the differential diagnosis of meningitis. Cerebrospinal fluid samples were collected on the day of fever onset, as well as on day 2 and 4 pre and post fever development. Tumor necrosis factor-α, interleukin-1β, interleukin-6, interleukin-8, transforming growth factor-β, and procalcitonin were subsequently analyzed using enzyme-linked immunosorbent assay analysis techniques. Inflammatory marker levels were compared among febrile aseptic, bacterial, and nonmeningitis patients to determine cerebrospinal fluid inflammatory changes over time. Significant increases in cerebrospinal fluid tumor necrosis factor -α, interleukin-1β, interleukin-6, and interleukin-8 levels were observed within patients with bacterial meningitis at fever onset, which was not evident in aseptic or nonmeningitis patients. Furthermore, significant increases in cerebrospinal fluid tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-8 levels were detected as early as 4 days prior to fever onset within patients with bacterial meningitis when compared with both aseptic and nonmeningitis groups. Interestingly, procalcitonin was only significantly increased in patients with bacterial meningitis on the fourth day post fever. The present study suggests that raised cerebrospinal fluid tumor necrosis factor -α, interleukin-1β, and interleukin-8 in a

  1. 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...

  2. Statistical optimization of medium composition for bacterial cellulose production by Gluconacetobacter hansenii UAC09 using coffee cherry husk extract--an agro-industry waste.

    Science.gov (United States)

    Rani, Mahadevaswamy Usha; Rastogi, Navin K; Appaiah, K A Anu

    2011-07-01

    During the production of grape wine, the formation of thick leathery pellicle/bacterial cellulose (BC) at the airliquid interface was due to the bacterium, which was isolated and identified as Gluconacetobacter hansenii UAC09. Cultural conditions for bacterial cellulose production from G. hansenii UAC09 were optimized by central composite rotatable experimental design. To economize the BC production, coffee cherry husk (CCH) extract and corn steep liquor (CSL) were used as less expensive sources of carbon and nitrogen, respectively. CCH and CSL are byproducts from the coffee processing and starch processing industry, respectively. The interactions between pH (4.5- 8.5), CSL (2-10%), alcohol (0.5-2%), acetic acid (0.5- 2%), and water dilution rate to CCH ratio (1:1 to 1:5) were studied using response surface methodology. The optimum conditions for maximum BC production were pH (6.64), CSL (10%), alcohol (0.5%), acetic acid (1.13%), and water to CCH ratio (1:1). After 2 weeks of fermentation, the amount of BC produced was 6.24 g/l. This yield was comparable to the predicted value of 6.09 g/l. This is the first report on the optimization of the fermentation medium by RSM using CCH extract as the carbon source for BC production by G. hansenii UAC09.

  3. Use of primer selection and restriction enzymes to assess bacterial community diversity in an agricultural soil used for potato production via terminal restriction fragment length polymorphism.

    Science.gov (United States)

    Fortuna, Ann-Marie; Marsh, Terence L; Honeycutt, C Wayne; Halteman, William A

    2011-08-01

    Terminal restriction fragment length polymorphism (T-RFLP) can be used to assess how land use management changes the dominant members of bacterial communities. We compared T-RFLP profiles obtained via amplification with forward primers (27, 63F) each coupled with the fluorescently labeled reverse primer (1392R) and multiple restriction enzymes to determine the best combination for interrogating soil bacterial populations in an agricultural soil used for potato production. Both primer pairs provide nearly universal recognition of a 1,400-bp sequence of the bacterial domain in the V(1)-V(3) region of the 16S ribosomal RNA (rRNA) gene relative to known sequences. Labeling the reverse primer allowed for direct comparison of each forward primer and the terminal restriction fragments' relative migration units obtained with each primer pair and restriction enzyme. Redundancy analysis (RDA) and nested multivariate analysis of variance (MANOVA) were used to assess the effects of primer pair and choice of restriction enzyme on the measured relative migration units. Our research indicates that the 63F-1392R amplimer pair provides a more complete description with respect to the bacterial communities present in this potato (Solanum tuberosum L.)-barley (Hordeum vulgare L.) rotation over seeded to crimson clover (Trifolium praense L.). Domain-specific 16S rRNA gene primers are rigorously tested to determine their ability to amplify across a target region of the gene. Yet, variability within or between T-RFLP profiles can result from factors independent of the primer pair. Therefore, researchers should use RDA and MANOVA analyses to evaluate the effects that additional laboratory and environmental variables have on bacterial diversity.

  4. Impact of the freeze-drying process on product appearance, residual moisture content, viability, and batch uniformity of freeze-dried bacterial cultures safeguarded at culture collections.

    Science.gov (United States)

    Peiren, Jindrich; Hellemans, Ann; De Vos, Paul

    2016-07-01

    In this study, causes of collapsed bacterial cultures in glass ampoules observed after freeze-drying were investigated as well as the influence of collapse on residual moisture content (RMC) and viability. Also, the effect of heat radiation and post freeze-drying treatments on the RMC was studied. Cake morphologies of 21 bacterial strains obtained after freeze-drying with one standard protocol could be classified visually into four major types: no collapse, porous, partial collapse, and collapse. The more pronounced the collapse, the higher residual moisture content of the freeze-dried product, ranging from 1.53 % for non-collapsed products to 3.62 % for collapsed products. The most important cause of collapse was the mass of the inserted cotton plug in the ampoule. Default cotton plugs with a mass between 21 and 30 mg inside the ampoule did not affect the viability of freeze-dried Aliivibrio fischeri LMG 4414(T) compared to ampoules without cotton plugs. Cotton plugs with a mass higher than 65 mg inside the ampoule induced a full collapsed product with rubbery look (melt-back) and decreasing viability during storage. Heat radiation effects in the freeze-drying chamber and post freeze-drying treatments such as exposure time to air after freeze-drying and manifold drying time prior to heat sealing of ampoules influenced the RMC of freeze-dried products. To produce uniform batches of freeze-dried bacterial strains with intact cake structures and highest viabilities, inserted cotton plugs should not exceed 21 mg per ampoule. Furthermore, heat radiation effects should be calculated in the design of the primary drying phase and manifold drying time before heat sealing should be determined as a function of exposure time to air.

  5. 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

  6. Composition of epicuticular wax on Prosopis glandulosa leaves

    Energy Technology Data Exchange (ETDEWEB)

    Mayeux, H.S. Jr.; Wilkinson, R.E. (USDA-ARS, Temple, TX (USA) Univ. of Georgia Agricultural Experiment Station, Experiment (USA))

    1990-06-01

    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{sub n}) of alkanes ranged from 25 to 31, with a maximum (57%) at 29. Esters consisted of fatty acids with C{sub n} of 16, 18, and 20, with most (70%) at 18 and fatty alcohols with C{sub n} of 24-32. The C{sub 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 {sup 14}CO{sub 2} for 4 h, 60% of the recovered {sup 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 {sup 14}C in free fatty alcohols increased from ca. 12% immediately after exposure to {sup 14}CO{sub 2} to 55% at 8 h. Little {sup 14}C was associated with other wax components over the 24-h period; 3% or less was incorporated into alkanes.

  7. 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.

  8. Studies on the factors modulating indole-3-acetic acid production in endophytic bacterial isolates from Piper nigrum and molecular analysis of ipdc gene.

    Science.gov (United States)

    Jasim, B; Jimtha John, C; Shimil, V; Jyothis, M; Radhakrishnan, E K

    2014-09-01

    The study mainly aimed quantitative analysis of IAA produced by endophytic bacteria under various conditions including the presence of extract from Piper nigrum. Analysis of genetic basis of IAA production was also conducted by studying the presence and diversity of the ipdc gene among the selected isolates. Five endophytic bacteria isolated previously from P. nigrum were used for the study. The effect of temperature, pH, agitation, tryptophan concentration and plant extract on modulating IAA production of selected isolates was analysed by colorimetric method. Comparative and quantitative analysis of IAA production by colorimetric isolates under optimal culture condition was analysed by HPTLC method. Presence of ipdc gene and thereby biosynthetic basis of IAA production among the selected isolates were studied by PCR-based amplification and subsequent insilico analysis of sequence obtained. Among the selected bacterial isolates from P. nigrum, isolate PnB 8 (Klebsiella pneumoniae) was found to have the maximum yield of IAA under various conditions optimized and was confirmed by colorimetric, HPLC and HPTLC analysis. Very interestingly, the study showed stimulating effect of phytochemicals from P. nigrum on IAA production by endophytic bacteria isolated from same plant. This study is unique because of the selection of endophytes from same source for comparative and quantitative analysis of IAA production under various conditions. Study on stimulatory effect of phytochemicals on bacterial IAA production as explained in the study is a novel approach. Studies on molecular basis of IAA production which was confirmed by sequence analysis of ipdc gene make the study scientifically attractive. Even though microbial production of IAA is well known, current report on detailed optimization, effect of plant extract and molecular confirmation of IAA biosynthesis is comparatively novel in its approach. © 2014 The Society for Applied Microbiology.

  9. 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)

  10. 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

  11. Bacterial canker of plum caused by Pseudomonas syringae pathovars, as a serious threat for plum production in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Janse, J.D.; Bruine, de A.; Vink, P.; Pham, K.T.K.

    2012-01-01

    In the Netherlands, bacterial canker of plum trees (Prunus domestica) caused by Pseudomonas syringae pathovars syringae and morsprunorum is a recent and serious problem. The trunks of the affected plum trees are girdled by cankers resulting in relatively sudden death of the trees 1 to 4 years after

  12. 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, ...

  13. 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.

  14. Skimmiwallinin, an additional skimmiwallinol derivative from the cuticular wax of Cocos nucifera.

    Science.gov (United States)

    Escalante-Erosa, Fabiola; Fernández-Concha, Germán Carnevali; Peña-Rodríguez, Luis M

    2009-01-01

    AgNO3-impregnated prep-TLC purification of the wax extract of Cocos nucifera allowed the isolation and identification of skimmiwallinin as an additional skimmiwallinol derivative from the cuticular wax of coconut palms. Identification was based on the comparison of its spectroscopic data with those reported in the literature.

  15. Growth, yield and quality responses to gibberellic acid (GA3)of Wax ...

    African Journals Online (AJOL)

    Administrator

    2011-09-26

    Sep 26, 2011 ... quality of jambu madu fruits under field conditions. Key words: Gibberellin, growth, quality, wax apple, yield. INTRODUCTION. The wax apple or jambu var. jambu air madu is a tropical .... according to Miller and Rice-Evans (1997). Total anthocyanin contents of the hydrophilic extracts were measured by the ...

  16. 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...

  17. Investigations of Properties of Wax Mixtures Used in the Investment Casting Technology – New Investigation Methods

    Directory of Open Access Journals (Sweden)

    J. Zych

    2012-09-01

    Full Text Available The results of testing of the selected group of wax mixtures used in the investment casting technology, are presented in the paper. Themeasurements of the kinetics of the mixtures shrinkage and changes of viscous-plastic properties as a temperature function wereperformed. The temperature influence on bending strength of wax mixtures was determined.

  18. 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.

  19. Influence of the cycle length on the production of PHA and polyglucose from glycerol by bacterial enrichments in sequencing batch reactors.

    Science.gov (United States)

    Moralejo-Gárate, Helena; Palmeiro-Sánchez, Tania; Kleerebezem, Robbert; Mosquera-Corral, Anuska; Campos, José Luis; van Loosdrecht, Mark C M

    2013-12-01

    PHA, a naturally occurring biopolymer produced by a wide range of microorganisms, is known for its applications as bioplastic. In recent years the use of agro-industrial wastewater as substrate for PHA production by bacterial enrichments has attracted considerable research attention. Crude glycerol as generated during biodiesel production is a waste stream that due to its high organic matter content and low price could be an interesting substrate for PHA production. Previously we have demonstrated that when glycerol is used as substrate in a feast-famine regime, PHA and polyglucose are simultaneously produced as storage polymers. The work described in this paper aimed at understanding the effect of the cycle length on the bacterial enrichment process with emphasis on the distribution of glycerol towards PHA and polyglucose. Two sequencing batch reactors where operated with the same hydraulic and biomass retention time. A short cycle length (6 h) favored polyglucose production over PHA, whereas at long cycle length (24 h) PHA was more favored. In both communities the same microorganism appeared dominating, suggesting a metabolic rather than a microbial competition response. Moreover, the presence of ammonium during polymer accumulation did not influence the maximum amount of PHA that was attained. © 2013 Wiley Periodicals, Inc.

  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. SUPERKILLER Complex Components Are Required for the RNA Exosome-Mediated Control of Cuticular Wax Biosynthesis in Arabidopsis Inflorescence Stems1[OPEN

    Science.gov (United States)

    Zhao, Lifang; Kunst, Ljerka

    2016-01-01

    ECERIFERUM7 (CER7)/AtRRP45B core subunit of the exosome, the main cellular 3′-to-5′ exoribonuclease, is a positive regulator of cuticular wax biosynthesis in Arabidopsis (Arabidopsis thaliana) inflorescence stems. CER7-dependent exosome activity determines stem wax load by controlling transcript levels of the wax-related gene CER3. Characterization of the second-site suppressors of the cer7 mutant revealed that small interfering RNAs (siRNAs) are direct effectors of CER3 expression. To explore the relationship between the exosome and posttranscriptional gene silencing (PTGS) in regulating CER3 transcript levels, we investigated two additional suppressor mutants, wax restorer1 (war1) and war7. We show that WAR1 and WAR7 encode Arabidopsis SUPERKILLER3 (AtSKI3) and AtSKI2, respectively, components of the SKI complex that associates with the exosome during cytoplasmic 3′-to-5′ RNA degradation, and that CER7-dependent regulation of wax biosynthesis also requires participation of AtSKI8. Our study further reveals that it is the impairment of the exosome-mediated 3′-5′ decay of CER3 transcript in the cer7 mutant that triggers extensive production of siRNAs and efficient PTGS of CER3. This identifies PTGS as a general mechanism for eliminating highly abundant endogenous transcripts that is activated when 3′-to-5′ mRNA turnover by the exosome is disrupted. Diminished efficiency of PTGS in ski mutants compared with cer7, as evidenced by lower accumulation of CER3-related siRNAs, suggests that reduced amounts of CER3 transcript are available for siRNA synthesis, possibly because CER3 mRNA that does not interact with SKI is degraded by 5′-to-3′ XRN4 exoribonuclease. PMID:27208312

  2. Development and evaluation of an emulsified paraffin wax dispenser for season-long mating disruption of Grapholita molesta in commercial peach orchards.

    Science.gov (United States)

    De Lame, Frédérique M; Miller, James R; Attrerholt, Cynthia A; Gut, Larry J

    2007-08-01

    The University of California at Davis patented the use of emulsified wax to release pheromones for mating disruption. Advantages of these dispensers include low cost, self-adhesion, and biodegradation. We compared the efficacy and practicality of Confuse-OFM, a commercial emulsified wax formulation of oriental fruit moth, Grapiholita molesta (Busck), pheromone with those of Check-Mate OFM-F sprayable pheromone and Isomate-M 100 polyethylene tube dispensers in commercial peach (Prunus spp.) orchards. Efficacy was measured with male captures in pheromone-, virgin female-, and liquid attractant-baited bucket traps as well as by noting injury to shoots and fruit. Two applications of Confuse-OFM were as effective as two applications of CheckMate OFM-F and one application of Isomate-M 100. However, Confuse-OFM was tedious to apply and wasted pheromone with an initially high release rate. We developed a new emulsified wax formulation (Wax Dollops) that maintained release rates above a 5 mg/ha/h threshold twice as long as Confuse-OFM in the laboratory. Field trials confirmed that one application of 3-ml dollops (590 dollops per ha) provided season-long (approximately 15 wk) control equivalent to that of Isomate-M 100 and Confuse-OFM applied as described above. Several applicators were developed for Wax Dollops, including a pneumatic gun that shot dollops >2 m. However, the most efficient method for application was wiping dollops onto tree branches by using a flat-bladed spatula. This research was the basis for a new line of commercial pheromone pest control products equally effective to current commercial formulations but with advantages in cost and flexibility.

  3. 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

    ... International Trade Administration Petroleum Wax Candles From the People's Republic of China: Continuation of... the antidumping duty order on petroleum wax candles from the People's Republic of China (``PRC... of initiation of the sunset review of the antidumping duty order on petroleum wax candles from the...

  4. A method to isolate bacterial communities and characterize ecosystems from food products: Validation and utilization in as a reproducible chicken meat model.

    Science.gov (United States)

    Rouger, Amélie; Remenant, Benoit; Prévost, Hervé; Zagorec, Monique

    2017-04-17

    Influenced by production and storage processes and by seasonal changes the diversity of meat products microbiota can be very variable. Because microbiotas influence meat quality and safety, characterizing and understanding their dynamics during processing and storage is important for proposing innovative and efficient storage conditions. Challenge tests are usually performed using meat from the same batch, inoculated at high levels with one or few strains. Such experiments do not reflect the true microbial situation, and the global ecosystem is not taken into account. Our purpose was to constitute live stocks of chicken meat microbiotas to create standard and reproducible ecosystems. We searched for the best method to collect contaminating bacterial communities from chicken cuts to store as frozen aliquots. We tested several methods to extract DNA of these stored communities for subsequent PCR amplification. We determined the best moment to collect bacteria in sufficient amounts during the product shelf life. Results showed that the rinsing method associated to the use of Mobio DNA extraction kit was the most reliable method to collect bacteria and obtain DNA for subsequent PCR amplification. Then, 23 different chicken meat microbiotas were collected using this procedure. Microbiota aliquots were stored at -80°C without important loss of viability. Their characterization by cultural methods confirmed the large variability (richness and abundance) of bacterial communities present on chicken cuts. Four of these bacterial communities were used to estimate their ability to regrow on meat matrices. Challenge tests performed on sterile matrices showed that these microbiotas were successfully inoculated and could overgrow the natural microbiota of chicken meat. They can therefore be used for performing reproducible challenge tests mimicking a true meat ecosystem and enabling the possibility to test the influence of various processing or storage conditions on complex meat

  5. 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.

  6. Bacterial Proteasomes.

    Science.gov (United States)

    Jastrab, Jordan B; Darwin, K Heran

    2015-01-01

    Interest in bacterial proteasomes was sparked by the discovery that proteasomal degradation is required for the pathogenesis of Mycobacterium tuberculosis, one of the world's deadliest pathogens. Although bacterial proteasomes are structurally similar to their eukaryotic and archaeal homologs, there are key differences in their mechanisms of assembly, activation, and substrate targeting for degradation. In this article, we compare and contrast bacterial proteasomes with their archaeal and eukaryotic counterparts, and we discuss recent advances in our understanding of how bacterial proteasomes function to influence microbial physiology.

  7. Physico-chemical properties, wax composition, aroma profiles, and antioxidant activity of granulated non-centrifugal sugars from sugarcane cultivars of Thailand

    OpenAIRE

    Weerawatanakorn, Monthana; Asikin, Yonathan; Takahashi, Makoto; Tamaki, Hajime; Wada, Koji; Ho, Chi-Tang; Chuekittisak, Raweewan

    2016-01-01

    Non-centrifugal cane sugar (NCS) is globally consumed and has various health benefits. It is mostly produced in hardened block form, which is less convenient than in granulated form for food applications. In terms of the traditional processing of NCS, preparation of granulated products is difficult due to the impurities found in the cane juice extracted from the whole stalk. Therefore, the aim of this study was to characterize and determine the physico-chemical properties, wax composition (po...

  8. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to policosanols from sugar cane wax and maintenance of normal blood LDL-cholesterol concentrations (ID 1747, 1748, 1864, 1951, 1954, 4693) and maintenance of normal, blood HDL-cholesterol concentrations (ID 1747, 1748, 1864, 1951, 1954, 4693) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    claims in relation to policosanols from sugar cane wax and maintenance of normal blood LDL-cholesterol concentrations and maintenance of normal blood HDL-cholesterol concentrations. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article...

  9. 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

  10. 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®

  11. Removal of wax and stickies from OCC by flotation. Progress report No. 2, April 1--June 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Doshi, M.R.; Dyer, J. [Doshi and Associates, Inc., Appleton, WI (United States); Heise, O. [Voith Sulzer Papertechnology, Appleton, WI (United States)

    1998-08-01

    During the second quarter of the study the authors examined the conditions necessary for repulping a mixture of wax-coated boards that would be conducive to the flotation of detached wax. Also important for the economic viability of a waxed-board repulping process is adequate defibering of the recovered paper. Several methods for the dewaxing of pulped waxed-boards were investigated. The authors have continued to survey the literature to determine what other efforts are being made to ameliorate the impact of waxed boards during the recycling of OCC.

  12. 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.

  13. 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)

  14. Effects of photoperiod on nutrient removal, biomass production, and algal-bacterial population dynamics in lab-scale photobioreactors treating municipal wastewater.

    Science.gov (United States)

    Lee, Chang Soo; Lee, Sang-Ah; Ko, So-Ra; Oh, Hee-Mock; Ahn, Chi-Yong

    2015-01-01

    Effects of photoperiod were investigated in lab-scale photobioreactors containing algal-bacterial consortia to reduce organic nutrients from municipal wastewater. Under three photoperiod conditions (12 h:12 h, 36 h:12 h, and 60 h:12 h dark–light cycles), nutrient removals and biomass productions were measured along with monitoring microbial population dynamics. After a batch operation for 12 days, 59–80% carbon, 35–88% nitrogen, and 43–89% phosphorus were removed from influents, respectively. In this study, carbon removal was related positively to the length of dark cycles, while nitrogen and phosphorus removals inversely. On the contrast, the highest microbial biomass in terms of chlorophyll a, dry cell weight, and algal/bacterial rRNA gene markers was produced under the 12 h:12 h dark–light cycle among the three photoperiods. The results showed 1) simultaneous growths between algae and bacteria in the microbial consortia and 2) efficient nitrogen and phosphorus removals along with high microbial biomass production under prolonged light conditions. Statistical analyses indicated that carbon removal was significantly related to the ratio of bacteria to algae in the microbial consortia along with prolonged dark conditions (p < 0.05). In addition, the ratio of nitrogen removal to phosphorus removal decreased significantly under prolonged dark conditions (p < 0.001). These results indicated that the photoperiod condition has remarkable impacts on adjusting nutrient removal, producing microbial biomass, and altering algal-bacterial population dynamics. Therefore, the control of photoperiod was suggested as an important operating parameter in the algal wastewater treatment.

  15. Advanced glycation end products dietary restriction effects on bacterial gut microbiota in peritoneal dialysis patients; a randomized open label controlled trial.

    Directory of Open Access Journals (Sweden)

    Rabi Yacoub

    Full Text Available The modern Western diet is rich in advanced glycation end products (AGEs. We have previously shown an association between dietary AGEs and markers of inflammation and oxidative stress in a population of end stage renal disease (ESRD patients undergoing peritoneal dialysis (PD. In the current pilot study we explored the effects of dietary AGEs on the gut bacterial microbiota composition in similar patients. AGEs play an important role in the development and progression of cardiovascular (CVD disease. Plasma concentrations of different bacterial products have been shown to predict the risk of incident major adverse CVD events independently of traditional CVD risk factors, and experimental animal models indicates a possible role AGEs might have on the gut microbiota population. In this pilot randomized open label controlled trial, twenty PD patients habitually consuming a high AGE diet were recruited and randomized into either continuing the same diet (HAGE, n = 10 or a one-month dietary AGE restriction (LAGE, n = 10. Blood and stool samples were collected at baseline and after intervention. Variable regions V3-V4 of 16s rDNA were sequenced and taxa was identified on the phyla, genus, and species levels. Dietary AGE restriction resulted in a significant decrease in serum Nε-(carboxymethyl lysine (CML and methylglyoxal-derivatives (MG. At baseline, our total cohort exhibited a lower relative abundance of Bacteroides and Alistipes genus and a higher abundance of Prevotella genus when compared to the published data of healthy population. Dietary AGE restriction altered the bacterial gut microbiota with a significant reduction in Prevotella copri and Bifidobacterium animalis relative abundance and increased Alistipes indistinctus, Clostridium citroniae, Clostridium hathewayi, and Ruminococcus gauvreauii relative abundance. We show in this pilot study significant microbiota differences in peritoneal dialysis patients' population, as well as the effects

  16. Advanced glycation end products dietary restriction effects on bacterial gut microbiota in peritoneal di