Ear wax

MedlinePlus

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

Mammalian Wax Biosynthesis

PubMed Central

Cheng, Jeffrey B.; Russell, David W.

2009-01-01

Wax monoesters are synthesized by the esterification of fatty alcohols and fatty acids. A mammalian enzyme that catalyzes this reaction has not been isolated. We used expression cloning to identify cDNAs encoding a wax synthase in the mouse preputial gland. The wax synthase gene is located on the X chromosome and encodes a member of the acyltransferase family of enzymes that synthesize neutral lipids. Expression of wax synthase in cultured cells led to the formation of wax monoesters from straight chain saturated, unsaturated, and polyunsaturated fatty alcohols and acids. Polyisoprenols also were incorporated into wax monoesters by the enzyme. The wax synthase had little or no ability to synthesize cholesteryl esters, diacylglycerols, or triacylglycerols, whereas other acyltransferases, including the acyl-CoA:monoacylglycerol acyltransferase 1 and 2 enzymes and the acyl-CoA:diacylglycerol acyltransferase 1 and 2 enzymes, exhibited modest wax monoester synthesis activities. Confocal light microscopy indicated that the wax synthase was localized in membranes of the endoplasmic reticulum. Wax synthase mRNA was abundant in tissues rich in sebaceous glands such as the preputial gland and eyelid and was present at lower levels in other tissues. Coexpression of cDNAs specifying fatty acyl-CoA reductase 1 and wax synthase led to the synthesis of wax monoesters. The data suggest that wax monoester synthesis in mammals involves a two step biosynthetic pathway catalyzed by fatty acyl-CoA reductase and wax synthase enzymes. PMID:15220349

Microencapsulation of Flavors in Carnauba Wax

PubMed Central

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. PMID:22315575

Microencapsulation of flavors in carnauba wax.

PubMed

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.

Morphology and networks of sunflower wax crystals in organogel

USDA-ARS?s Scientific Manuscript database

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...

Possibility of wax control techniques in Indonesian oil fields

NASA Astrophysics Data System (ADS)

Abdurrahman, M.; Ferizal, F. H.; Husna, U. Z.; Pangaribuan, L.

2018-03-01

Wax is one of the common problem which can reduce the oil production, especially for the reservoir with high paraffin content case. When the temperature of crude oil is lower than pour point, wax molecules can begin rapidly precipitated. The impacts of this problem are the clogging of production equipment, sealing off the pores in the reservoir, and decreasing production flow rate. In order to solve the wax problem, several methods have been applied in some oil fields in the world. For example, chemical methods in Jiangsu field (China) and Mumbai High field (India), hot water in Mangala field (India), magnetic method in Daqing field (China), water-dispersible in Bakken basin (US), and microbial in Jidong field (China). In general, the various crude oils present in the Indonesia contain wax content between 10%-39% and pour point of 22°C-49°C. Hot water and chemical method are commonly used to solve wax problems in Indonesian oil fields. However, the primary solution is magnetic method, and the secondary solution is water dispersible.

Process for upgrading wax from Fischer-Tropsch synthesis

DOEpatents

Derr, Jr., W. Rodman; Garwood, William E.; Kuo, James C.; Leib, Tiberiu M.; Nace, Donald M.; Tabak, Samuel A.

1987-01-01

The waxy liquid phase of an oil suspension of Fischer-Tropsch catalyst containing dissolved wax is separated out and the wax is converted by hydrocracking, dewaxing or by catalytic cracking with a low activity catalyst to provide a highly olefinic product which may be further converted to premium quality gasoline and/or distillate fuel.

Process for upgrading wax from Fischer-Tropsch synthesis

DOEpatents

Derr, W.R. Jr.; Garwood, W.E.; Kuo, J.C.; Leib, T.M.; Nace, D.M.; Tabak, S.A.

1987-08-04

The waxy liquid phase of an oil suspension of Fischer-Tropsch catalyst containing dissolved wax is separated out and the wax is converted by hydrocracking, dewaxing or by catalytic cracking with a low activity catalyst to provide a highly olefinic product which may be further converted to premium quality gasoline and/or distillate fuel. 2 figs.

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

PubMed

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

2014-02-15

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

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

USDA-ARS?s Scientific Manuscript database

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...

Shape-tunable wax microparticle synthesis via microfluidics and droplet impact

PubMed Central

Lee, Doojin; Beesabathuni, Shilpa N.; Shen, Amy Q.

2015-01-01

Spherical and non-spherical wax microparticles are generated by employing a facile two-step droplet microfluidic process which consists of the formation of molten wax microdroplets in a flow-focusing microchannel and their subsequent off-chip crystallization and deformation via microdroplet impingement on an immiscible liquid interface. Key parameters on the formation of molten wax microdroplets in a microfluidic channel are the viscosity of the molten wax and the interfacial tension between the dispersed and continuous fluids. A cursory phase diagram of wax morphology transition is depicted depending on the Capillary number and the Stefan number during the impact process. A combination of numerical simulation and analytical modeling is carried out to understand the physics underlying the deformation and crystallization process of the molten wax. The deformation of wax microdroplets is dominated by the viscous and thermal effects rather than the gravitational and buoyancy effects. Non-isothermal crystallization kinetics of the wax illustrates the time dependent thermal effects on the droplet deformation and crystallization. The work presented here will benefit those interested in the design and production criteria of soft non-spherical particles (i.e., alginate gels, wax, and polymer particles) with the aid of time and temperature mediated solidification and off-chip crosslinking. PMID:26697124

Phototransformation of the herbicide sulcotrione on maize cuticular wax.

PubMed

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

2006-05-01

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

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

PubMed

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.

Cloning and Characterization of GLOSSY1, a Maize Gene Involved in Cuticle Membrane and Wax Production1[w

PubMed Central

Sturaro, Monica; Hartings, Hans; Schmelzer, Elmon; Velasco, Riccardo; Salamini, Francesco; Motto, Mario

2005-01-01

The cuticle covering the aerial organs of land plants plays a protective role against several biotic and abiotic stresses and, in addition, participates in a variety of plant-insect interactions. Here, we describe the molecular cloning and characterization of the maize (Zea mays) GLOSSY1 (GL1) gene, a component of the pathway leading to cuticular wax biosynthesis in seedling leaves. The genomic and cDNA sequences we isolated differ significantly in length and in most of the coding region from those previously identified. The predicted GL1 protein includes three histidine-rich domains, the landmark of a family of membrane-bound desaturases/hydroxylases, including fatty acid-modifying enzymes. GL1 expression is not restricted to the juvenile developmental stage of the maize plant, pointing to a broader function of the gene product than anticipated on the basis of the mutant phenotype. Indeed, in addition to affecting cuticular wax biosynthesis, gl1 mutations have a pleiotropic effect on epidermis development, altering trichome size and impairing cutin structure. Of the many wax biosynthetic genes identified so far, only a few from Arabidopsis (Arabidopsis thaliana) were found to be essential for normal cutin formation. Among these is WAX2, which shares 62% identity with GL1 at the protein level. In wax2-defective plants, cutin alterations induce postgenital organ fusion. This trait is not displayed by gl1 mutants, suggesting a different role of the maize and Arabidopsis cuticle in plant development. PMID:15849306

Organogels of vegetable oil with plant wax – trans/saturated fat replacements

USDA-ARS?s Scientific Manuscript database

This featured article reviews recent advances on the development of trans fat-free, low saturated fat food products from organogels formed by a plant wax in a vegetable oil. Plant waxes are of great interest in this research area because they are obtained as by-products during the oil refining proce...

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

PubMed

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

2002-08-01

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

Identification of the Wax Ester Synthase/Acyl-Coenzyme A:Diacylglycerol Acyltransferase WSD1 Required for Stem Wax Ester Biosynthesis in Arabidopsis12[W][OA

PubMed Central

Li, Fengling; Wu, Xuemin; Lam, Patricia; Bird, David; Zheng, Huanquan; Samuels, Lacey; Jetter, Reinhard; Kunst, Ljerka

2008-01-01

Wax esters are neutral lipids composed of aliphatic alcohols and acids, with both moieties usually long-chain (C16 and C18) or very-long-chain (C20 and longer) carbon structures. They have diverse biological functions in bacteria, insects, mammals, and terrestrial plants and are also important substrates for a variety of industrial applications. In plants, wax esters are mostly found in the cuticles coating the primary shoot surfaces, but they also accumulate to high concentrations in the seed oils of a few plant species, including jojoba (Simmondsia chinensis), a desert shrub that is the major commercial source of these compounds. Here, we report the identification and characterization of WSD1, a member of the bifunctional wax ester synthase/diacylglycerol acyltransferase gene family, which plays a key role in wax ester synthesis in Arabidopsis (Arabidopsis thaliana) stems, as first evidenced by severely reduced wax ester levels of in the stem wax of wsd1 mutants. In vitro assays using protein extracts from Escherichia coli expressing WSD1 showed that this enzyme has a high level of wax synthase activity and approximately 10-fold lower level of diacylglycerol acyltransferase activity. Expression of the WSD1 gene in Saccharomyces cerevisiae resulted in the accumulation of wax esters, but not triacylglycerol, indicating that WSD1 predominantly functions as a wax synthase. Analyses of WSD1 expression revealed that this gene is transcribed in flowers, top parts of stems, and leaves. Fully functional yellow fluorescent protein-tagged WSD1 protein was localized to the endoplasmic reticulum, demonstrating that biosynthesis of wax esters, the final products of the alcohol-forming pathway, occurs in this subcellular compartment. PMID:18621978

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

PubMed

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.

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

PubMed

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.

21 CFR 184.1976 - Candelilla wax.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Candelilla wax. 184.1976 Section 184.1976 Food and... Substances Affirmed as GRAS § 184.1976 Candelilla wax. (a) Candelilla wax (CAS Reg. No. 8006-44-8) is obtained from the candelilla plant. It is a hard, yellowish-brown, opaque-to-translucent wax. Candelilla...

21 CFR 184.1976 - Candelilla wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Candelilla wax. 184.1976 Section 184.1976 Food and... Substances Affirmed as GRAS § 184.1976 Candelilla wax. (a) Candelilla wax (CAS Reg. No. 8006-44-8) is obtained from the candelilla plant. It is a hard, yellowish-brown, opaque-to-translucent wax. Candelilla...

Bacterial symbionts and natural products

PubMed Central

Crawford, Jason M.; Clardy, Jon

2011-01-01

The study of bacterial symbionts of eukaryotic hosts has become a powerful discovery engine for chemistry. This highlight looks at four case studies that exemplify the range of chemistry and biology involved in these symbioses: a bacterial symbiont of a fungus and a marine invertebrate that produce compounds with significant anticancer activity, and bacterial symbionts of insects and nematodes that produce compounds that regulate multilateral symbioses. In the last ten years, a series of shocking revelations – the molecular equivalents of a reality TV show’s uncovering the true parents of a well known individual or a deeply hidden family secret – altered the study of genetically encoded small molecules, natural products for short. These revelations all involved natural products produced by bacterial symbionts, and while details differed, two main plot lines emerged: parentage, in which the real producers of well known natural products with medical potential were not the organisms from which they were originally discovered, and hidden relationships, in which bacterially produced small molecules turned out to be the unsuspected regulators of complex interactions. For chemists, these studies led to new molecules, new biosynthetic pathways, and an understanding of the biological functions these molecules fulfill. PMID:21594283

Structural features of reconstituted wheat wax films

PubMed Central

Pambou, Elias; Li, Zongyi; Campana, Mario; Hughes, Arwel; Clifton, Luke; Gutfreund, Philipp; Foundling, Jill

2016-01-01

Cuticular waxes are essential for the well-being of all plants, from controlling the transport of water and nutrients across the plant surface to protecting them against external environmental attacks. Despite their significance, our current understanding regarding the structure and function of the wax film is limited. In this work, we have formed representative reconstituted wax film models of controlled thicknesses that facilitated an ex vivo study of plant cuticular wax film properties by neutron reflection (NR). Triticum aestivum L. (wheat) waxes were extracted from two different wheat straw samples, using two distinct extraction methods. Waxes extracted from harvested field-grown wheat straw using supercritical CO2 are compared with waxes extracted from laboratory-grown wheat straw via wax dissolution by chloroform rinsing. Wax films were produced by spin-coating the two extracts onto silicon substrates. Atomic force microscopy and cryo-scanning electron microscopy imaging revealed that the two reconstituted wax film models are ultrathin and porous with characteristic nanoscale extrusions on the outer surface, mimicking the structure of epicuticular waxes found upon adaxial wheat leaf surfaces. On the basis of solid–liquid and solid–air NR and ellipsometric measurements, these wax films could be modelled into two representative layers, with the diffuse underlying layer fitted with thicknesses ranging from approximately 65 to 70 Å, whereas the surface extrusion region reached heights exceeding 200 Å. Moisture-controlled NR measurements indicated that water penetrated extensively into the wax films measured under saturated humidity and under water, causing them to hydrate and swell significantly. These studies have thus provided a useful structural basis that underlies the function of the epicuticular waxes in controlling the water transport of crops. PMID:27466439

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

PubMed

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

2015-07-01

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

21 CFR 178.3710 - Petroleum wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Petroleum wax. 178.3710 Section 178.3710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants...

21 CFR 178.3710 - Petroleum wax.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Petroleum wax. 178.3710 Section 178.3710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants...

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

PubMed

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

2018-01-01

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

Applications of micro-SAXS/WAXS to study polymer fibers

NASA Astrophysics Data System (ADS)

Riekel, C.

2003-01-01

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

Bacterial Cellulose Production from Industrial Waste and by-Product Streams

PubMed Central

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

2015-01-01

The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients. PMID:26140376

Thermal Cracking to Improve the Qualification of the Waxes

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Policosanol fabrication from insect wax and optimization by response surface methodology

PubMed Central

Ma, Jinju; Zhang, Hong

2018-01-01

Background Insect wax is a famous biological resource for the role in economic production in China. Insect wax is a good source of policosanol, which may is a candidate supplement in foodstuff and pharmaceuticals that has important physiological activities. Therefore, this work aims to investigate a high-yield and rapid method for policosanol fabrication from insect wax. Results The conditions for policosanol fabrication were optimized as follows: an oil bath temperature of 112.7°C and reductant dosage of 0.97 g (used for the reduction of 10.00 g of insect wax). The yield of policosanol reached 83.20%, which was 4 times greater than that of existing methods, such as saponification. The total content of policosanol obtained under the optimal conditions reached 87%. In other words, a high yield of policosanol was obtained from insect wax (723.84 mg/g), that was 55 times higher than that generated from beeswax-brown via saponification. The concentrations of metal residues in policosanol were within the limits of the European Union regulations and EFSA stipulation. The LD50 values for oral doses of insect wax and policosanol were both > 5 g/kg. Conclusion Policosanol was fabricated via solvent-free reduction from insect wax using LiAlH4 at a high yield. The fabrication conditions were optimized. Policosanol and insect wax showed high security, which made them potential candidates as supplements in foods, pharmaceuticals and cosmetics. The rapid and high-yield method has great potential for commercial manufacturing of policosanol. PMID:29763430

21 CFR 872.6890 - Intraoral dental wax.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intraoral dental wax. 872.6890 Section 872.6890...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6890 Intraoral dental wax. (a) Identification. Intraoral dental wax is a device made of wax intended to construct patterns from which custom made metal...

21 CFR 872.6890 - Intraoral dental wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intraoral dental wax. 872.6890 Section 872.6890...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6890 Intraoral dental wax. (a) Identification. Intraoral dental wax is a device made of wax intended to construct patterns from which custom made metal...

21 CFR 872.6890 - Intraoral dental wax.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

21 CFR 872.6890 - Intraoral dental wax.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intraoral dental wax. 872.6890 Section 872.6890...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6890 Intraoral dental wax. (a) Identification. Intraoral dental wax is a device made of wax intended to construct patterns from which custom made metal...

21 CFR 872.6890 - Intraoral dental wax.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intraoral dental wax. 872.6890 Section 872.6890...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6890 Intraoral dental wax. (a) Identification. Intraoral dental wax is a device made of wax intended to construct patterns from which custom made metal...

21 CFR 172.888 - Synthetic petroleum wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

21 CFR 172.888 - Synthetic petroleum wax.

Code of Federal Regulations, 2010 CFR

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...

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

PubMed

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.

Wax Reinforces Honeycomb During Machining

NASA Technical Reports Server (NTRS)

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.

21 CFR 172.890 - Rice bran wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Rice bran wax. 172.890 Section 172.890 Food and... Multipurpose Additives § 172.890 Rice bran wax. Rice bran wax may be safely used in food in accordance with the following conditions: (a) It is the refined wax obtained from rice bran and meets the following...

21 CFR 172.890 - Rice bran wax.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Rice bran wax. 172.890 Section 172.890 Food and... Multipurpose Additives § 172.890 Rice bran wax. Rice bran wax may be safely used in food in accordance with the following conditions: (a) It is the refined wax obtained from rice bran and meets the following...

Occurrence and patterns of waxes in Neisseriaceae.

PubMed

Bryn, K; Jantzen, E; Bovre, K

1977-09-01

Forty-five strains classified in the family Neisseriaceae were analysed for wax esters by gas-liquid chromatography. The amounts and types of waxes varied between the taxa. Waxes were not detected in 16 strains of 'true neisseriae' (genus Neisseria) or in two strains of Kingella, but they were found in all 'false neisseriae', in all species of Moraxella except Moraxella phenylpyrouvica, in five out of 10 strains of Acintobacter, and in all strains of a group of psychrophilic, oxidase-positive organisms. The chain lengths of the wax esters ranged from C24 to C42, with C36 predominating. In all taxa, esters with even numbers of carbon atoms constituted 70 to 100% of the total. Saturated, mono-unsaturated and diunsaturated waxes were found. Acinetobacter strains were characterized by large amounts (30 to 98%) of di-unsaturated wax esters; such waxes did not exceed 8% in the 'false neisseriae' or Moraxella spp. Waxes of strains belonging to the psychrophilic, oxidase-positive group generally resembled those found in Moraxella. Wax esters with odd numbers of carbon atoms were abundant in M. lacunata (29%), M. atlantae (15%) and in the psychorophilic group (19 to 28%); long-chain esters (C40 or above) were characteristic of M. atlantae (30%) and one strain of M. osloensis (26%).

CER4 Encodes an Alcohol-Forming Fatty Acyl-Coenzyme A Reductase Involved in Cuticular Wax Production in Arabidopsis1[W

PubMed Central

Rowland, Owen; Zheng, Huanquan; Hepworth, Shelley R.; Lam, Patricia; Jetter, Reinhard; Kunst, Ljerka

2006-01-01

A waxy cuticle that serves as a protective barrier against uncontrolled water loss and environmental damage coats the aerial surfaces of land plants. It is composed of a cutin polymer matrix and waxes. Cuticular waxes are complex mixtures of very-long-chain fatty acids and their derivatives. We report here the molecular cloning and characterization of CER4, a wax biosynthetic gene from Arabidopsis (Arabidopsis thaliana). Arabidopsis cer4 mutants exhibit major decreases in stem primary alcohols and wax esters, and slightly elevated levels of aldehydes, alkanes, secondary alcohols, and ketones. This phenotype suggested that CER4 encoded an alcohol-forming fatty acyl-coenzyme A reductase (FAR). We identified eight FAR-like genes in Arabidopsis that are highly related to an alcohol-forming FAR expressed in seeds of jojoba (Simmondsia chinensis). Molecular characterization of CER4 alleles and genomic complementation revealed that one of these eight genes, At4g33790, encoded the FAR required for cuticular wax production. Expression of CER4 cDNA in yeast (Saccharomyces cerevisiae) resulted in the accumulation of C24:0 and C26:0 primary alcohols. Fully functional green fluorescent protein-tagged CER4 protein was localized to the endoplasmic reticulum in yeast cells by confocal microscopy. Analysis of gene expression by reverse transcription-PCR indicated that CER4 was expressed in leaves, stems, flowers, siliques, and roots. Expression of a β-glucuronidase reporter gene driven by the CER4 promoter in transgenic plants was detected in epidermal cells of leaves and stems, consistent with a dedicated role for CER4 in cuticular wax biosynthesis. CER4 was also expressed in all cell types in the elongation zone of young roots. These data indicate that CER4 is an alcohol-forming FAR that has specificity for very-long-chain fatty acids and is responsible for the synthesis of primary alcohols in the epidermal cells of aerial tissues and in roots. PMID:16980563

Post waxing folliculitis: a clinicopathological evaluation.

PubMed

Khanna, Neena; Chandramohan, Kudigili; Khaitan, Binod K; Singh, Manoj K

2014-07-01

Epilation by waxing is one of the common methods of removing unwanted body hair, and follicular papules following this cosmetic procedure are not uncommon. However, this not so uncommon problem has not been clinically and histopathologically evaluated. To study the clinicopathological profile of folliculitis temporally developing after epilation by waxing. Clinical and histopathological evaluation was done in 28 patients who developed follicular papules within a period of eight weeks following a history of epilation by waxing over the same area. The demographic profile and the method and frequency of waxing were noted. The symptoms associated with and the morphology and distribution of the follicular lesions were recorded. A punch biopsy was done from a representative follicular lesion to evaluate the pathological changes. All the patients recruited were females (100%) with a mean age of 24.33 + 2.43 years. While all 28 patients had waxed their forearms, 25 had waxed their arms, 18 their legs, and 10 their thighs. The most common sites affected by folliculitis were arms (25; 100%) and forearms (15/28; 53.6%). Thighs, though least frequently waxed, were involved in seven (70%) subjects. Of these, seven (25%) women complained of itching. The lesions in all patients were erythematous to skin colored follicular papules, though two (7.1%) patients also had nodular lesions. A punch biopsy done showed features suggestive of pseudofolliculitis. A granulomatous reaction was seen in nine (32.1%) biopsies. A foreign body identified as a hair shaft was seen in seven (25%) biopsies and keratin in one biopsy. Folliculitis following epilation by waxing is more frequent in proximal parts of the extremities than in distal parts, even though distal parts are more frequently waxed. In one-third of the cases, post-waxing folliculitis is due to foreign body reaction to hair shaft or keratin and resembles pseudofolliculitis. To know exact pathogenesis, additional biopsies with multiple

21 CFR 186.1555 - Japan wax.

Code of Federal Regulations, 2010 CFR

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...

21 CFR 184.1976 - Candelilla wax.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... It is a hard, yellowish-brown, opaque-to-translucent wax. Candelilla wax is prepared by immersing the plants in boiling water containing sulfuric acid and skimming off the wax that rises to the surface. It... this chapter and in hard candy as defined in § 170.3(n)(25) of this chapter. (d) Prior sanctions for...

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

PubMed Central

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

Bacterial cellulose as an example product for sustainable production and consumption.

PubMed

Jang, Woo Dae; Hwang, Ji Hyeon; Kim, Hyun Uk; Ryu, Jae Yong; Lee, Sang Yup

2017-09-01

Life cycle of bacterial cellulose. Sustainable production and consumption of bio-based products are showcased using bacterial cellulose as an example. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Extracellular lipids of Camelina sativa: characterization of chloroform-extractable waxes from aerial and subterranean surfaces.

PubMed

Razeq, Fakhria M; Kosma, Dylan K; Rowland, Owen; Molina, Isabel

2014-10-01

Camelina sativa (L.) Crantz is an emerging low input, stress tolerant crop with seed oil composition suitable for biofuel and bioproduct production. The chemical compositions and ultrastructural features of surface waxes from C. sativa aerial cuticles, seeds, and roots were analyzed using gas chromatography and microscopy. Alkanes, primary fatty alcohols, and free fatty acids were common components of all analyzed organs. A particular feature of leaf waxes was the presence of alkyl esters of long-chain fatty acids and very long-chain fatty alcohols, ranging from C38 to C50 and dominated by C42, C44 and C46 homologues. Stem waxes were mainly composed of non-sterol pentacyclic triterpenes. Flowers accumulated significant amounts of methyl-branched iso-alkanes (C29 and C31 total carbon number) in addition to straight-chain alkanes. Seed waxes were mostly primary fatty alcohols of up to 32 carbons in length and unbranched C29 and C31 alkanes. The total amount of identified wax components extracted by rapid chloroform dipping of roots was 280μgg(-1) (fresh weight), and included alkyl hydroxycinnamates, predominantly alkyl coumarates and alkyl caffeates. This study provides qualitative and quantitative information on the waxes of C. sativa root, shoot, and seed boundary tissues, allowing the relative activities of wax biosynthetic pathways in each respective plant organ to be assessed. This detailed description of the protective surface waxes of C. sativa may provide insights into its drought-tolerant and pathogen-resistant properties, and also identifies C. sativa as a potential source of renewable high-value natural products. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sintering of wax for controlling release from pellets.

PubMed

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

2007-09-14

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

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

NASA Astrophysics Data System (ADS)

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).

Identification of avian wax synthases

PubMed Central

2012-01-01

Background Bird species show a high degree of variation in the composition of their preen gland waxes. For instance, galliform birds like chicken contain fatty acid esters of 2,3-alkanediols, while Anseriformes like goose or Strigiformes like barn owl contain wax monoesters in their preen gland secretions. The final biosynthetic step is catalyzed by wax synthases (WS) which have been identified in pro- and eukaryotic organisms. Results Sequence similarities enabled us to identify six cDNAs encoding putative wax synthesizing proteins in chicken and two from barn owl and goose. Expression studies in yeast under in vivo and in vitro conditions showed that three proteins from chicken performed WS activity while a sequence from chicken, goose and barn owl encoded a bifunctional enzyme catalyzing both wax ester and triacylglycerol synthesis. Mono- and bifunctional WS were found to differ in their substrate specificities especially with regard to branched-chain alcohols and acyl-CoA thioesters. According to the expression patterns of their transcripts and the properties of the enzymes, avian WS proteins might not be confined to preen glands. Conclusions We provide direct evidence that avian preen glands possess both monofunctional and bifunctional WS proteins which have different expression patterns and WS activities with different substrate specificities. PMID:22305293

Natural oils and waxes: studies on stick bases.

PubMed

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.

Emulsions of sunflower wax in pectin aqueous solutions: Physical characterization and stability.

PubMed

Chalapud, Mayra C; Baümler, Erica R; Carelli, Amalia A

2018-06-01

The knowledge of the stability and physical properties of film-forming solutions is necessary for optimizing the process design of films. In order to evaluate their applicability for the production of edible films, the rheological and microstructural properties, particle size and physicochemical stability of aqueous emulsions of low methoxyl pectin and sunflower waxes from normal and high-oleic hybrids were assessed. Emulsions were prepared with different pectin concentrations (1, 2 and 3% w/w) and wax proportions (0.1, 0.2 and 0.3 g/g pectin). The rheological behavior was best described by the power law model. The values of the behavior index (n) were close to 1, exhibiting a behavior close to Newtonian fluids. The addition of waxes caused an increase in viscosity and shear stress. The particle size of the emulsions made with waxes from high-oleic sunflower was smaller than those from the normal hybrid. In most cases, size distributions with greater height and less amplitude were obtained, mainly when the pectin content was higher. Confocal images allowed to observe the presence of waxes and their dispersion in the pectin matrix. Destabilization phenomena such as sedimentation, coalescence and creaming were observed at long test times independent of the wax origin. These results evidence the potential use of these emulsions for the manufacture of edible films. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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.

21 CFR 184.1978 - Carnauba wax.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the Brazilian wax palm Copernicia cerifera Martius. The wax is hard, brittle, sparingly soluble in cold organic solvents and insoluble in water. It is marketed in five grades designated No. 1 through No...

21 CFR 184.1978 - Carnauba wax.

Code of Federal Regulations, 2012 CFR

2012-04-01

... from the leaves and buds of the Brazilian wax palm Copernicia cerifera Martius. The wax is hard, brittle, sparingly soluble in cold organic solvents and insoluble in water. It is marketed in five grades...

21 CFR 184.1978 - Carnauba wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... from the leaves and buds of the Brazilian wax palm Copernicia cerifera Martius. The wax is hard, brittle, sparingly soluble in cold organic solvents and insoluble in water. It is marketed in five grades...

21 CFR 184.1978 - Carnauba wax.

Code of Federal Regulations, 2013 CFR

2013-04-01

... from the leaves and buds of the Brazilian wax palm Copernicia cerifera Martius. The wax is hard, brittle, sparingly soluble in cold organic solvents and insoluble in water. It is marketed in five grades...

RDR1 and SGS3, components of RNA-mediated gene silencing, are required for the regulation of cuticular wax biosynthesis in developing inflorescence stems of Arabidopsis.

PubMed

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

2012-08-01

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).

Self-Replenishable Anti-Waxing Organogel Materials.

PubMed

Yao, Xi; Wu, Shuwang; Chen, Lie; Ju, Jie; Gu, Zhandong; Liu, Mingjie; Wang, Jianjun; Jiang, Lei

2015-07-27

Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self-replenishable organogel material which shows ultra-low adhesion to solidified paraffin wax and crude oil by absorption of low-molar-mass oil from its crude-oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

The effects of light, primary production, and temperature on bacterial production at Station ALOHA

NASA Astrophysics Data System (ADS)

Viviani, D. A.; Church, M. J.

2016-02-01

In the open oceans, bacterial metabolism is responsible for a large fraction of the movement of reduced carbon through these ecosystems. While broad meta-analyses suggest that factors such as temperature or primary production control rates of bacterial production over large geographic scales, to date little is known about how these factors influence variability in bacterial production in the open sea. Here we present two years of measurements of 3H-leucine incorporation, a proxy for bacterial production, at the open ocean field site of the Hawaii Ocean Time-series, Station ALOHA (22° 45'N, 158° 00'W). By examining 3H-leucine incorporation over monthly, daily, and hourly scales, this work provides insight into processes controlling bacterial growth in this persistently oligotrophic habitat. Rates of 3H-leucine incorporation were consistently 60% greater when measured in the light than in the dark, highlighting the importance of sunlight in fueling bacterial metabolism in this ecosystem. Over diel time scales, rates of 3H-leucine incorporation were quasi-sinusoidal, with rates in the light higher near midday, while rates in the dark were greatest after sunset. Depth-integrated (0 -125 m) rates of 3H-leucine incorporation in both light and dark were more variable ( 5- and 4-fold, respectively) than coincident measurements of primary production ( 2-fold). On average, rates of bacterial production averaged 2 and 4% of primary production (in the dark and light, respectively). At near-monthly time scales, rates of 3H-leucine incorporation in both light and dark were significantly related to temperature. Our results suggest that in the subtropical oligotrophic Pacific, bacterial production appears decoupled from primary production as a result of seasonal-scale variations in temperature and light.

Dental wax decreases calculus accumulation in small dogs.

PubMed

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.

Uniform discotic wax particles via electrospray emulsification.

PubMed

Mejia, Andres F; He, Peng; Luo, Dawei; Marquez, Manuel; Cheng, Zhengdong

2009-06-01

We present a novel colloidal discotic system: the formation and self-assembling of wax microdisks with a narrow size distribution. Uniform wax emulsions are first fabricated by electrospraying of melt alpha-eicosene. The size of the emulsions can be flexibly tailored by varying the flow rate of the discontinuous phase, its electric conductivity, and the applied voltage. The process of entrainment of wax droplets, vital for obtaining uniform emulsions, is facilitated by the reduction of air-water surface tension and the density of the continuous phase. Then uniform wax discotic particles are produced via phase transition, during which the formation of a layered structure of the rotator phase of wax converts the droplets, one by one, into oblate particles. The time span for the conversion from spherical emulsions to disk particles is linearly dependent on the size of droplets in the emulsion, indicating the growth of a rotator phase from surface to the center is the limiting step in the shape transition. Using polarized light microscopy, the self-assembling of wax disks is observed by increasing disk concentration and inducing depletion attraction among disks, where several phases, such as isotropic, condensed, columnar stacking, and self-assembly of columnar rods are present sequentially during solvent evaporation of a suspension drop.

Hot Oil Removes Wax

NASA Technical Reports Server (NTRS)

Herzstock, James J.

1991-01-01

Mineral oil heated to temperature of 250 degrees F (121 degrees C) found effective in removing wax from workpieces after fabrication. Depending upon size and shape of part to be cleaned of wax, part immersed in tank of hot oil, and/or interior of part flushed with hot oil. Pump, fittings, and ancillary tooling built easily for this purpose. After cleaning, innocuous oil residue washed off part by alkaline aqueous degreasing process. Serves as relatively safe alternative to carcinogenic and environmentally hazardous solvent perchloroethylene.

pH-sensitive wax emulsion copolymerization with acrylamide hydrogel using gamma irradiation for dye removal

NASA Astrophysics Data System (ADS)

Ghobashy, Mohamed Mohamady; Elhady, Mohamed., A.

2017-05-01

Emulsion polymerization is an efficient method for the production of new wax-hydrogel matrices of cetyl alcohol: stearic acid wax and acrylamide hydrogel using triethylamine (TEA) as an emulsifier. A cross-linking reaction occurred when a mixture of wax-hydrogel solution was irradiated with gamma rays at a dose of 20 kGy. The gelation percentage of the matrices (CtOH-StA/PAAm) was 86%, which indicates that a sufficiently high conversion occurred in these new wax-hydrogel matrices. The ability of PAAm and CtOH-StA/PAAm as an adsorbent for dye removal was investigated. The removal of three reactive dyes, namely Remazol Red (RR), Amido Black (AB), and Toluidine Blue (TB), from aqueous solutions depends on the pH of the dye solution. Removal efficiency was investigated by UV spectrophotometry, and the results showed the affinity of the wax hydrogel to adsorb TB was 98% after 320 min. Fourier transform infrared-attenuated total reflectance spectra confirmed the cross-linking process involved between the chains of wax and hydrogel; furthermore, scanning electron microscopy images showed that the wax and hydrogel were completely miscible to form a single matrix. Swelling measurements showed the high affinity of adsorbed dyes from aqueous solutions at different pH values to the wax-hydrogel network; the highest swelling values of 13.05 and 8.24 (g/g) were observed at pH 10 and 6, respectively

Bone wax in Neurosurgery: A Review.

PubMed

Das, Joe M

2018-05-09

In this occasion of 125 years after the so-called "initial" use of bone wax (BW) by Sir Victor Horsley, a review of this age-old hemostatic agent deemed appropriate. The first use of BW for hemostasis is dated back to the 18 th century when modeling or candle wax was used for hemostasis. Though the pioneers in the usage of BW in craniofacial surgeries were Belloq, Professor Khristian Khristianovich Salomon and François Magendie, its first successful use in neurosurgery was demonstrated by Henri Ferdinand Dolbeau in 1864, following the extirpation of a frontal osteoma. This was further popularized by Sir Victor Alexander Haden Horsley, the father of British neurosurgery, who is often incorrectly mentioned as the inventor of BW. Originally derived from bees' wax, the currently available commercial preparation contains paraffin wax and Isopropyl palmitate in addition. The main action being mechanical tamponade, BW has found several other uses in neurosurgery, other than being a hemostatic agent. Though it is cost-effective, the use of BW is associated with several complications also, including ineffective bone healing and infection. So several other alternatives are coming up, but none has yet been able to fully replace "Horsley's wax" till date. Copyright © 2018 Elsevier Inc. All rights reserved.

Verifying Dissolution Of Wax From Hardware Surfaces

NASA Technical Reports Server (NTRS)

Montoya, Benjamina G.

1995-01-01

Wax removed by cleaning solvent revealed by cooling solution with liquid nitrogen. Such improved procedure and test needed in case of hardware that must be protected by wax during machining or plating but required to be free of wax during subsequent use. Improved cleaning procedure and test take less than 5 minutes. Does not require special skill or equipment and performs at cleaning site. In addition, enables recovery of all cleaning solvent.

Interspecific utilisation of wax in comb building by honeybees

NASA Astrophysics Data System (ADS)

Hepburn, H. Randall; Radloff, Sarah E.; Duangphakdee, Orawan; Phaincharoen, Mananya

2009-06-01

Beeswaxes of honeybee species share some homologous neutral lipids; but species-specific differences remain. We analysed behavioural variation for wax choice in honeybees, calculated the Euclidean distances for different beeswaxes and assessed the relationship of Euclidean distances to wax choice. We tested the beeswaxes of Apis mellifera capensis, Apis florea, Apis cerana and Apis dorsata and the plant and mineral waxes Japan, candelilla, bayberry and ozokerite as sheets placed in colonies of A. m. capensis, A. florea and A. cerana. A. m. capensis accepted the four beeswaxes but removed Japan and bayberry wax and ignored candelilla and ozokerite. A. cerana colonies accepted the wax of A. cerana, A. florea and A. dorsata but rejected or ignored that of A. m. capensis, the plant and mineral waxes. A. florea colonies accepted A. cerana, A. dorsata and A. florea wax but rejected that of A. m. capensis. The Euclidean distances for the beeswaxes are consistent with currently prevailing phylogenies for Apis. Despite post-speciation chemical differences in the beeswaxes, they remain largely acceptable interspecifically while the plant and mineral waxes are not chemically close enough to beeswax for their acceptance.

Properties of cookies made with natural wax-vegetable oil organogels

USDA-ARS?s Scientific Manuscript database

Organogels prepared with a natural wax and a vegetable oil were examined as alternatives to a commercial margarine in cookie. To investigate effects of wax and vegetable oil on properties of cookie dough and cookies, organogels prepared from four different waxes including sunflower wax, rice bran wa...

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

PubMed

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.

Production of bacterial cellulose from alternate feedstocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

D. N. Thompson; M. A. Hamilton

2000-05-07

Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS and HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

Production of Bacterial Cellulose from Alternate Feedstocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, David Neil; Hamilton, Melinda Ann

2000-05-01

Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS & HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

FORMULATION AND EVALUATION OF RICE BRAN WAX AS OINTMENT BASE

PubMed Central

Bhalekar, M; Manish, Lavhale; Krishna, Sini

2004-01-01

Rice Bran wax is obtained from natural sources and is abundantly available in the country. Rice bran wax is suitable for use in chocolate enrobes, as an enteric coating for candy and lozenges, as a plasticizing material in chewing gums etc. Present study attempts to find if rice bran wax is useful as ointment base. The oleaginous type ointment base is prepared by using rice bran wax and evaluated for speardabililty, water number and active ingredient diffusibility. The results obtained in the present study indicate, rice bran wax can be used as a good component in ointment base, comparable with white wax. PMID:22557151

Chemical and physical analyses of wax ester properties

PubMed Central

Patel, Sejal; Nelson, Dennis R.; Gibbs, Allen G.

2001-01-01

Wax esters are major constituents of the surface lipids in many terrestrial arthropods, but their study is complicated by their diversity. We developed a procedure for quantifying isomers in mixtures of straight-chain saturated and unsaturated wax esters having the same molecular weights, using single-ion monitoring of the total ion current data from gas chromatography-mass spectrometry. We examined the biological consequences of structural differences by measuring the melting temperatures, Tm, of >60 synthetic wax esters, containing 26–48 carbon atoms. Compounds containing saturated alcohol and acid moieties melted at 38–73°C. The main factor affecting Tm was the total chain length of the wax ester, but the placement of the ester bond also affected Tm. Insertion of a double bond into either the alcohol or acid moiety decreased Tm by ∼30°C. Simple mixtures of wax esters with n-alkanes melted several °C lower than predicted from the melting points of the component lipids. Our results indicate that the wax esters of primary alcohols that are most typically found on the cuticle of terrestrial arthropods occur in a solid state under physiological conditions, thereby conferring greater waterproofing. Wax esters of secondary alcohols, which occur on melanopline grasshoppers, melted >60°C below primary esters of the same molecular weight and reduced Tm of the total surface lipids to environmental values. PMID:15455064

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

PubMed

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.

Getting in shape: molten wax drop deformation and solidification at an immiscible liquid interface.

PubMed

Beesabathuni, Shilpa N; Lindberg, Seth E; Caggioni, Marco; Wesner, Chris; Shen, Amy Q

2015-05-01

The controlled production of non-spherical shaped particles is important for many applications such as food processing, consumer goods, adsorbents, drug delivery, and optical sensing. In this paper, we investigated the deformation and simultaneous solidification of millimeter size molten wax drops as they impacted an immiscible liquid interface of higher density. By varying initial temperature and viscoelasticity of the molten drop, drop size, impact velocity, viscosity and temperature of the bath fluid, and the interfacial tension between the molten wax and bath fluid, spherical molten wax drops impinged on a cooling water bath and were arrested into non-spherical solidified particles in the form of ellipsoid, mushroom, disc, and flake-like shapes. We constructed cursory phase diagrams for the various particle shapes generated over a range of Weber, Capillary, Reynolds, and Stefan numbers, governed by the interfacial, inertial, viscous, and thermal effects. We solved a simplified heat transfer problem to estimate the time required to initiate the solidification at the interface of a spherical molten wax droplet and cooling aqueous bath after impact. By correlating this time with the molten wax drop deformation history captured from high speed imaging experiments, we elucidate the delicate balance of interfacial, inertial, viscous, and thermal forces that determine the final morphology of wax particles. Copyright © 2015 Elsevier Inc. All rights reserved.

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

PubMed

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.

Precision phenotyping of epicuticular waxes associated with insect resistance

USDA-ARS?s Scientific Manuscript database

Accurate phenotyping is imperative for linkage mapping and association genetics. Amounts and types of epicuticular waxes on the leaf surface are important for plant-insect interactions. In onion, specific wax profiles are associated with resistance to the insect pest Thrips tabaci. Epicuticular wax ...

In vivo evaluation of insect wax for hair growth potential.

PubMed

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.

In vivo evaluation of insect wax for hair growth potential

PubMed Central

Ma, Jinju

2018-01-01

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

Statistical Optimization of Sustained Release Venlafaxine HCI Wax Matrix Tablet.

PubMed

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.

Statistical Optimization of Sustained Release Venlafaxine HCI Wax Matrix Tablet

PubMed Central

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 32 full factorial design was applied to systemically optimize the drug release profile. Amounts of carnauba wax (X1) and bees wax (X2) were selected as independent variables and release after 12 h and time required for 50% (t50) 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 t50 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. PMID:20046773

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

PubMed

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.

21 CFR 184.1976 - Candelilla wax.

Code of Federal Regulations, 2013 CFR

2013-04-01

... obtained from the candelilla plant. It is a hard, yellowish-brown, opaque-to-translucent wax. Candelilla wax is prepared by immersing the plants in boiling water containing sulfuric acid and skimming off the... practice: in chewing gum as defined in § 170.3(n)(6) of this chapter and in hard candy as defined in § 170...

21 CFR 184.1976 - Candelilla wax.

Code of Federal Regulations, 2012 CFR

2012-04-01

... obtained from the candelilla plant. It is a hard, yellowish-brown, opaque-to-translucent wax. Candelilla wax is prepared by immersing the plants in boiling water containing sulfuric acid and skimming off the... practice: in chewing gum as defined in § 170.3(n)(6) of this chapter and in hard candy as defined in § 170...

Waxes: A Forgotten Topic in Lipid Teaching.

ERIC Educational Resources Information Center

Dominguez, Eva; Heredia, Antonio

1998-01-01

Reviews the biological importance of the lipids categorized as waxes and describes some of the organic chemistry of these compounds. Presents a short laboratory exercise on the extraction of plant waxes and their analysis by thin layer chromatography. (Author/CCM)

Stomatal Density Influences Leaf Water and Leaf Wax D/H Values in Arabidopsis

NASA Astrophysics Data System (ADS)

Lee, H.; Feakins, S. J.; Sternberg, L. O.

2014-12-01

The hydrogen isotopic composition (δD) of plant leaf wax is a powerful tool to study the hydrology of past and present environments. The δD value of leaf waxes is known to primarily reflect the δD value of source water, modified by biological fractionations commonly summarized as the 'net or apparent' fractionation. It remains a challenge, however, to quantitatively relate the isotopic composition of the end product (wax) back to that of the precursor (water) because multiple isotope effects contributing to the net fractionation are not yet well understood. Transgenic variants have heretofore unexplored potential to isolate individual isotope effects. Here we report the first hydrogen isotopic measurements from transgenic Arabidopsis thaliana plants with calculations of leaf water enrichment, net and biosynthetic fractionation values from measured δD of plant waters and leaf wax n-alkanes. We employed transgenic Arabidopsis leaves, engineered to have different stomatal density, by differential expression of the stomatal growth hormone stomagen. Comparison of variants and wild types allow us to isolate the effects of stomatal density on leaf water and the net fractionation expressed by leaf wax biomarkers. Results show that transgenic leaves with denser pores have more enriched leaf water and leaf wax δD values than wild type and even more so than transgenic leaves with sparse stomata (difference of 10 ‰). Our findings that stomatal density controls leaf water and leaf wax δD values adds insights into the cause of variations in net fractionations between species, as well as suggesting that geological variations in stomatal density may modulate the sedimentary leaf wax δD record. In nature, stomatal density varies between species and environments, and all other factors being equal, this will contribute to variations in fractionations observed. Over geological history, lower stomatal densities occur at times of elevated pCO2; our findings predict reduced leaf

Migration of mineral hydrocarbons into foods. 2. Polystyrene, ABS, and waxed paperboard containers for dairy products.

PubMed

Castle, L; Kelly, M; Gilbert, J

1993-01-01

Migration of mineral hydrocarbons into dairy products and sunflower oil (fatty food simulant) has been studied using a gas chromatographic procedure. The food contact materials examined were polystyrene and ABS pots and tubs, and waxed paperboard. Levels of mineral oil in the polystyrene and ABS articles ranged from 0.3 to 5.5% w/w (13 to 366 mg/dm2) and as a coating on the paperboard ranged from 1.0 to 7.7% (55 to 565 mg/dm2). Exposure conditions were 7 days at 4 degrees C for the dairy products and 10 days at 40 degrees C for the oil. However, individual serving milk and creams (UHT) were retail samples which were stored at ambient temperature before analysis. Migration into the milk products was less than 3 mg/kg. Transfer to sunflower oil simulant and into individual serving milk products was much higher at levels up to 150 mg/kg (2 mg/dm2) and 90 mg/kg (4 mg/dm2) for the oil and milk respectively.

Release from or through a wax matrix system. I. Basic release properties of the wax matrix system.

PubMed

Yonezawa, Y; Ishida, S; Sunada, H

2001-11-01

Release properties from a wax matrix tablet was examined. To obtain basic release properties, the wax matrix tablet was prepared from a physical mixture of drug and wax powder (hydrogenated caster oil) at a fixed mixing ratio. Properties of release from the single flat-faced surface or curved side surface of the wax matrix tablet were examined. The applicability of the square-root time law and of Higuchi equations was confirmed. The release rate constant obtained as g/min(1/2) changed with the release direction. However, the release rate constant obtained as g/cm2 x min(1/2) was almost the same. Hence it was suggested that the release property was almost the same and the wax matrix structure was uniform independent of release surface or direction at a fixed mixing ratio. However, these equations could not explain the entire release process. The applicability of a semilogarithmic equation was not as good compared with the square-root time law or Higuchi equation. However, it was revealed that the semilogarithmic equation was available to simulate the entire release process, even though the fit was somewhat poor. Hence it was suggested that the semilogarithmic equation was sufficient to describe the release process. The release rate constant was varied with release direction. However, these release rate constants were expressed by a function of the effective surface area and initial amount, independent of the release direction.

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

NASA Astrophysics Data System (ADS)

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.

Transient silencing of the KASII genes is feasible in Nicotiana benthamiana for metabolic engineering of wax ester composition

PubMed Central

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

2015-01-01

The beta-ketoacyl-ACP synthase II (KASII) is an enzyme in fatty acid biosynthesis, catalyzing the elongation of 16:0-acyl carrier protein (ACP) to 18:0-ACP in plastids. Mutations in KASII genes in higher plants can lead to lethality, which makes it difficult to utilize the gene for lipid metabolic engineering. We demonstrated previously that transient expression of plastid-directed fatty acyl reductases and wax ester synthases could result in different compositions of wax esters. We hypothesized that changing the ratio between C16 (palmitoyl-compounds) and C18 (stearoyl-compounds) in the plastidic acyl-ACP pool by inhibition of KASII expression would change the yield and composition of wax esters via substrate preference of the introduced enzymes. Here, we report that transient inhibition of KASII expression by three different RNAi constructs in leaves of N. benthamiana results in almost complete inhibition of KASII expression. The transient RNAi approach led to a shift of carbon flux from a pool of C18 fatty acids to C16, which significantly increased wax ester production in AtFAR6-containing combinations. The results demonstrate that transient inhibition of KASII in vegetative tissues of higher plants enables metabolic studies towards industrial production of lipids such as wax esters with specific quality and composition. PMID:26063537

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

NASA Astrophysics Data System (ADS)

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.

Epicuticular Wax Crystals of Wollemia nobilis: Morphology and Chemical Composition

PubMed Central

Dragota, Simona; Riederer, Markus

2007-01-01

Background and Aims The morphology of the epicuticular leaf waxes of Wollemia nobilis (Araucariaceae) was studied with special emphasis on the relationship between the microstructure of epicuticular wax crystals and their chemical composition. Wollemia nobilis is a unique coniferous tree of the family Araucariaceae and is of very high scientific value as it is the sole living representative of an ancient genus, which until 1994 was known only from fossils. Methods Scanning electron microscopy (SEM), gas chromatography (GC) combined with mass spectrometry (GC–MS) and nuclear magnetic resonance spectroscopy (NMR) were used for characterizing the morphology and the chemical structure of the epicuticular wax layer of W. nobilis needles. Key Results The main component of the leaf epicuticular wax of W. nobilis is nonacosan-10-ol. This secondary alcohol together with nonacosane diols is responsible for the tubular habit of the epicuticular wax crystals. Scanning electron micrographs revealed differences in the fine structure of adaxial and abaxial leaf surfaces that could be explained by gas chromatographic studies after selective mechanical removal of the waxes. Conclusions SEM investigations established the tubular crystalline microstructure of the epicuticular wax of W. nobilis leaves. GC–MS and NMR experiments showed that nonacosan-10-ol is the major constituent of the epicuticular wax of W. nobilis leaves. PMID:17611192

Interior. Apparatus on table by door used for metalplating wax ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Interior. Apparatus on table by door used for metal-plating wax discs in order to make a steel master for use in mass production of phonograph records. Process used primarily from 1915 to 1928. - Thomas A. Edison Laboratories, Building No. 2, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

Preliminary evaluation of an aqueous wax emulsion for controlled-release coating.

PubMed

Walia, P S; Stout, P J; Turton, R

1998-02-01

The purpose of this work was to evaluate the use of an aqueous carnauba wax emulsion (Primafresh HS, Johnson Wax) in a spray-coating process. This involved assessing the effectiveness of the wax in sustaining the release of the drug, theophylline. Second, the process by which the drug was released from the wax-coated pellets was modeled. Finally, a method to determine the optimum blend of pellets with different wax thicknesses, in order to yield a zero-order release profile of the drug, was addressed. Nonpareil pellets were loaded with theophylline using a novel powder coating technique. These drug-loaded pellets were then coated with different levels of carnauba wax in a 6-in. diameter Plexiglas fluid bed with a 3.5-in. diameter Wurster partition. Drug release was measured using a spin-filter dissolution device. The study resulted in continuous carnauba wax coatings which showed sustained drug release profile characteristics typical of a barrier-type, diffusion-controlled system. The effect of varying wax thickness on the release profiles was investigated. It was observed that very high wax loadings would be required to achieve long sustained-release times. The diffusion model, developed to predict the release of the drug, showed good agreement with the experimental data. However, the data exhibited an initial lag-time for drug release which could not be predicted a priori based on the wax coating thickness. A method of mixing pellets with different wax thicknesses was proposed as a way to approximate zero-order release.

Effects of Fe nanoparticles on bacterial growth and biosurfactant production

NASA Astrophysics Data System (ADS)

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.

Plant surface wax affects parasitoid's response to host footprints

NASA Astrophysics Data System (ADS)

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.

Metabolic engineering of plant oils and waxes for use as industrial feedstocks.

PubMed

Vanhercke, Thomas; Wood, Craig C; Stymne, Sten; Singh, Surinder P; Green, Allan G

2013-02-01

Society has come to rely heavily on mineral oil for both energy and petrochemical needs. Plant lipids are uniquely suited to serve as a renewable source of high-value fatty acids for use as chemical feedstocks and as a substitute for current petrochemicals. Despite the broad variety of acyl structures encountered in nature and the cloning of many genes involved in their biosynthesis, attempts at engineering economic levels of specialty industrial fatty acids in major oilseed crops have so far met with only limited success. Much of the progress has been hampered by an incomplete knowledge of the fatty acid biosynthesis and accumulation pathways. This review covers new insights based on metabolic flux and reverse engineering studies that have changed our view of plant oil synthesis from a mostly linear process to instead an intricate network with acyl fluxes differing between plant species. These insights are leading to new strategies for high-level production of industrial fatty acids and waxes. Furthermore, progress in increasing the levels of oil and wax structures in storage and vegetative tissues has the potential to yield novel lipid production platforms. The challenge and opportunity for the next decade will be to marry these technologies when engineering current and new crops for the sustainable production of oil and wax feedstocks. © 2012 CSIRO Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Canned green beans and canned wax beans. 155.120... Vegetables § 155.120 Canned green beans and canned wax beans. (a) Identity—(1) Definition. Canned green beans and canned wax beans are the foods prepared from succulent pods of fresh green bean or wax bean plants...

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

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Canned green beans and canned wax beans. 155.120... Vegetables § 155.120 Canned green beans and canned wax beans. (a) Identity—(1) Definition. Canned green beans and canned wax beans are the foods prepared from succulent pods of fresh green bean or wax bean plants...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Canned green beans and canned wax beans. 155.120... Vegetables § 155.120 Canned green beans and canned wax beans. (a) Identity—(1) Definition. Canned green beans and canned wax beans are the foods prepared from succulent pods of fresh green bean or wax bean plants...

Gluconeogenesis from storage wax in the cotyledons of jojoba seedlings.

PubMed

Moreau, R A; Huang, A H

1977-08-01

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

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

PubMed Central

2013-01-01

Background Wax esters are highly hydrophobic neutral lipids that are major constituents of the cutin and suberin layer. Moreover they have favorable properties as a commodity for industrial applications. Through transgenic expression of wax ester biosynthetic genes in oilseed crops, it is possible to achieve high level accumulation of defined wax ester compositions within the seed oil to provide a sustainable source for such high value lipids. The fatty alcohol moiety of the wax esters is formed from plant-endogenous acyl-CoAs by the action of fatty acyl reductases (FAR). In a second step the fatty alcohol is condensed with acyl-CoA by a wax synthase (WS) to form a wax ester. In order to evaluate the specificity of wax ester biosynthesis, analytical methods are needed that provide detailed wax ester profiles from complex lipid extracts. Results We present a direct infusion ESI-tandem MS method that allows the semi-quantitative determination of wax ester compositions from complex lipid mixtures covering 784 even chain molecular species. The definition of calibration prototype groups that combine wax esters according to their fragmentation behavior enables fast quantitative analysis by applying multiple reaction monitoring. This provides a tool to analyze wax layer composition or determine whether seeds accumulate a desired wax ester profile. Besides the profiling method, we provide general information on wax ester analysis by the systematic definition of wax ester prototypes according to their collision-induced dissociation spectra. We applied the developed method for wax ester profiling of the well characterized jojoba seed oil and compared the profile with wax ester-accumulating Arabidopsis thaliana expressing the wax ester biosynthetic genes MaFAR and ScWS. Conclusions We developed a fast profiling method for wax ester analysis on the molecular species level. This method is suitable to screen large numbers of transgenic plants as well as other wax ester samples

Wax-incorporated emulsion gel beads of calcium pectinate for intragastric floating drug delivery.

PubMed

Sriamornsak, Pornsak; Asavapichayont, Panida; Nunthanid, Jurairat; Luangtana-Anan, Manee; Limmatvapirat, Sontaya; Piriyaprasarth, Suchada

2008-01-01

The purpose of this study was to prepare wax-incorporated pectin-based emulsion gel beads using a modified emulsion-gelation method. The waxes in pectin-olive oil mixtures containing a model drug, metronidazole, were hot-melted, homogenized and then extruded into calcium chloride solution. The beads formed were separated, washed with distilled water and dried for 12 h. The influence of various types and amounts of wax on floating and drug release behavior of emulsion gel beads of calcium pectinate was investigated. The drug-loaded gel beads were found to float on simulated gastric fluid if the sufficient amount of oil was used. Incorporation of wax into the emulsion gel beads affected the drug release. Water-soluble wax (i.e. polyethylene glycol) increased the drug release while other water-insoluble waxes (i.e. glyceryl monostearate, stearyl alcohol, carnauba wax, spermaceti wax and white wax) significantly retarded the drug release. Different waxes had a slight effect on the drug release. However, the increased amount of incorporated wax in the formulations significantly sustained the drug release while the beads remained floating. The results suggest that wax-incorporated emulsion gel beads could be used as a carrier for intragastric floating drug delivery.

Activities in support of the wax-impregnated wallboard concept

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kedl, R.J.; Stovall, T.K.

1989-01-01

The concept of octadecane wax impregnated wallboard for the passive solar application is a major thrust of the Oak Ridge National Laboratory (ORNL) Thermal Energy Storage (TES) program. Thus, ORNL has initiated a number of internal efforts in support of this concept. The results of these efforts are: The immersion process for filling wallboard with wax has been successfully sealed up from small samples to full-size sheets; analysis shows that the immersion process has the potential for achieving higher storage capacity than adding wax filled pellets to wallboard during its manufacture; analysis indicates that 75/degree/F is close to an optimummore » phase change temperature for the non-passive solar application; and the thermal conductivity of wallboard without wax has been measured and will be measured for wax impregnated wallboard. In addition, efforts are underway to confirm an analytical model that handles phase change wallboard for the passive solar application. 4 refs., 10 figs.« less

Self-association of plant wax components: a thermodynamic analysis.

PubMed

Casado, C G; Heredia, A

2001-01-01

Excess specific heat, C(p)()(E), of binary mixtures of selected components of plant cuticular waxes has been determined. This thermodynamic parameter gives an explanation of the special molecular arrangement in crystalline and amorphous zones of plant waxes. C(p)()(E) values indicate that hydrogen bonding between chains results in the formation of amorphous zones. Conclusions on the self-asembly process of plant waxes have been also made.

Preparation of margarines from organogels of sunflower wax and vegetable oils

USDA-ARS?s Scientific Manuscript database

It was previously reported that sunflower wax (SW) had high potential as an organogelator for soybean oil-based margarine and spread products. In this study twelve other vegetable oils were evaluated in a margarine formulation to test feasibility of utilization of SW as an alternative to solid fats ...

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

USDA-ARS?s Scientific Manuscript database

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...

Comparison the Marginal and Internal Fit of Metal Copings Cast from Wax Patterns Fabricated by CAD/CAM and Conventional Wax up Techniques.

PubMed

Vojdani, M; Torabi, K; Farjood, E; Khaledi, Aar

2013-09-01

Metal-ceramic crowns are most commonly used as the complete coverage restorations in clinical daily use. Disadvantages of conventional hand-made wax-patterns introduce some alternative ways by means of CAD/CAM technologies. This study compares the marginal and internal fit of copings cast from CAD/CAM and conventional fabricated wax-patterns. Twenty-four standardized brass dies were prepared and randomly divided into 2 groups according to the wax-patterns fabrication method (CAD/CAM technique and conventional method) (n=12). All the wax-patterns were fabricated in a standard fashion by means of contour, thickness and internal relief (M1-M12: representative of CAD/CAM group, C1-C12: representative of conventional group). CAD/CAM milling machine (Cori TEC 340i; imes-icore GmbH, Eiterfeld, Germany) was used to fabricate the CAD/CAM group wax-patterns. The copings cast from 24 wax-patterns were cemented to the corresponding dies. For all the coping-die assemblies cross-sectional technique was used to evaluate the marginal and internal fit at 15 points. The Student's t- test was used for statistical analysis (α=0.05). The overall mean (SD) for absolute marginal discrepancy (AMD) was 254.46 (25.10) um for CAD/CAM group and 88.08(10.67) um for conventional group (control). The overall mean of internal gap total (IGT) was 110.77(5.92) um for CAD/CAM group and 76.90 (10.17) um for conventional group. The Student's t-test revealed significant differences between 2 groups. Marginal and internal gaps were found to be significantly higher at all measured areas in CAD/CAM group than conventional group (p< 0.001). Within limitations of this study, conventional method of wax-pattern fabrication produced copings with significantly better marginal and internal fit than CAD/CAM (machine-milled) technique. All the factors for 2 groups were standardized except wax pattern fabrication technique, therefore, only the conventional group results in copings with clinically acceptable

75 FR 63200 - Petroleum Wax Candles From China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-14

... 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 from China. SUMMARY... antidumping duty order on petroleum wax candles from China would be likely to lead to continuation or...

Absorption and distribution of orally administered jojoba wax in mice.

PubMed

Yaron, A; Samoiloff, V; Benzioni, A

1982-03-01

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

A comprehensive review of glycosylated bacterial natural products

PubMed Central

Elshahawi, Sherif I.; Shaaban, Khaled A.; Kharel, Madan K.

2015-01-01

A systematic analysis of all naturally-occurring glycosylated bacterial secondary metabolites reported in the scientific literature up through early 2013 is presented. This comprehensive analysis of 15 940 bacterial natural products revealed 3426 glycosides containing 344 distinct appended carbohydrates and highlights a range of unique opportunities for future biosynthetic study and glycodiversification efforts. PMID:25735878

75 FR 38121 - Petroleum Wax Candles From China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-01

... From China AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on petroleum wax candles from China. SUMMARY: The Commission... petroleum wax candles from China would be likely to lead to continuation or recurrence of material injury...

Golgi- and Trans-Golgi Network-Mediated Vesicle Trafficking Is Required for Wax Secretion from Epidermal Cells1[W][OPEN

PubMed Central

McFarlane, Heather E.; Watanabe, Yoichiro; Yang, Weili; Huang, Yan; Ohlrogge, John; Samuels, A. Lacey

2014-01-01

Lipid secretion from epidermal cells to the plant surface is essential to create the protective plant cuticle. Cuticular waxes are unusual secretory products, consisting of a variety of highly hydrophobic compounds including saturated very-long-chain alkanes, ketones, and alcohols. These compounds are synthesized in the endoplasmic reticulum (ER) but must be trafficked to the plasma membrane for export by ATP-binding cassette transporters. To test the hypothesis that wax components are trafficked via the endomembrane system and packaged in Golgi-derived secretory vesicles, Arabidopsis (Arabidopsis thaliana) stem wax secretion was assayed in a series of vesicle-trafficking mutants, including gnom like1-1 (gnl1-1), transport particle protein subunit120-4, and echidna (ech). Wax secretion was dependent upon GNL1 and ECH. Independent of secretion phenotypes, mutants with altered ER morphology also had decreased wax biosynthesis phenotypes, implying that the biosynthetic capacity of the ER is closely related to its structure. These results provide genetic evidence that wax export requires GNL1- and ECH-dependent endomembrane vesicle trafficking to deliver cargo to plasma membrane-localized ATP-binding cassette transporters. PMID:24468625

Gluconeogenesis from Storage Wax in the Cotyledons of Jojoba Seedlings 1

PubMed Central

Moreau, Robert A.; Huang, Anthony H. C.

1977-01-01

The cotyledons of jojoba (Simmondsia chinensis) seeds contained 50 to 60% of their weight as intracellular wax esters. During germination there was a gradual decrease in the wax content with a concomitant rise in soluble carbohydrates, suggesting that the wax played the role of a food reserve. Thin layer chromatography revealed that both the fatty alcohol and fatty acid were metabolized. The disappearance of wax was matched with an increase of catalase, a marker enzyme of the gluconeogenic process in other fatty seedlings. Subcellular organelles were isolated by sucrose gradient centrifugation from the cotyledons at the peak stage of germination. The enzymes of the β oxidation of fatty acid and of the glyoxylate cycle were localized in the glyoxysomes but not in the mitochondria. The glyoxysomes had specific activities of individual enzymes similar to those of the castor bean glyoxysomes. An active alkaline lipase was detected in the wax bodies at the peak stage of germination but not in the ungerminated seeds. No lipase was detected in glyoxysomes or mitochondria. After the wax in the wax bodies had been extracted with diethyl ether, the organelle membrane was isolated and it still retained the alkaline lipase. The gluconeogenesis from wax in the jojoba seedling appears to be similar, but with modification, to that from triglyceride in other fatty seedlings. Images PMID:16660087

Wax layers on Cosmos bipinnatus petals contribute unequally to total petal water resistance.

PubMed

Buschhaus, Christopher; Hager, Dana; Jetter, Reinhard

2015-01-01

Cuticular waxes coat all primary aboveground plant organs as a crucial adaptation to life on land. Accordingly, the properties of waxes have been studied in much detail, albeit with a strong focus on leaf and fruit waxes. Flowers have life histories and functions largely different from those of other organs, and it remains to be seen whether flower waxes have compositions and physiological properties differing from those on other organs. This work provides a detailed characterization of the petal waxes, using Cosmos bipinnatus as a model, and compares them with leaf and stem waxes. The abaxial petal surface is relatively flat, whereas the adaxial side consists of conical epidermis cells, rendering it approximately 3.8 times larger than the projected petal area. The petal wax was found to contain unusually high concentrations of C(22) and C(24) fatty acids and primary alcohols, much shorter than those in leaf and stem waxes. Detailed analyses revealed distinct differences between waxes on the adaxial and abaxial petal sides and between epicuticular and intracuticular waxes. Transpiration resistances equaled 3 × 10(4) and 1.5 × 10(4) s m(-1) for the adaxial and abaxial surfaces, respectively. Petal surfaces of C. bipinnatus thus impose relatively weak water transport barriers compared with typical leaf cuticles. Approximately two-thirds of the abaxial surface water barrier was found to reside in the epicuticular wax layer of the petal and only one-third in the intracuticular wax. Altogether, the flower waxes of this species had properties greatly differing from those on vegetative organs. © 2015 American Society of Plant Biologists. All Rights Reserved.

Thermal behavior of gamma-irradiated low-density polyethylene/paraffin wax blend

NASA Astrophysics Data System (ADS)

Abdou, Saleh M.; Elnahas, H. H.; El-Zahed, H.; Abdeldaym, A.

2016-05-01

The thermal properties of low-density polyethylene (LDPE)/paraffin wax blends were studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and melt flow index (MFI). Blends of LDPE/wax in ratios of 100/0, 98/2, 96/4, 94/6, 92/8, 90/10 and 85/15 (w/w) were prepared by melt-mixing at the temperature of 150°C. It was found that increasing the wax content more than 15% leads to phase separation. DSC results showed that for all blends both the melting temperature (Tm) and the melting enthalpy (ΔHm) decrease linearly with an increase in wax content. TGA analysis showed that the thermal stability of all blends decreases linearly with increasing wax content. No clear correlation was observed between the melting point and thermal stability. Horowitz and Metzger method was used to determine the thermal activation energy (Ea). MFI increased exponentially by increasing the wax content. The effect of gamma irradiation on the thermal behavior of the blends was also investigated at different gamma irradiation doses. Significant correlations were found between the thermal parameters (Tm, ΔHm, T5%, Ea and MFI) and the amount of wax content and gamma irradiation.

Comparison the Marginal and Internal Fit of Metal Copings Cast from Wax Patterns Fabricated by CAD/CAM and Conventional Wax up Techniques

PubMed Central

Vojdani, M; Torabi, K; Farjood, E; Khaledi, AAR

2013-01-01

Statement of Problem: Metal-ceramic crowns are most commonly used as the complete coverage restorations in clinical daily use. Disadvantages of conventional hand-made wax-patterns introduce some alternative ways by means of CAD/CAM technologies. Purpose: This study compares the marginal and internal fit of copings cast from CAD/CAM and conventional fabricated wax-patterns. Materials and Method: Twenty-four standardized brass dies were prepared and randomly divided into 2 groups according to the wax-patterns fabrication method (CAD/CAM technique and conventional method) (n=12). All the wax-patterns were fabricated in a standard fashion by means of contour, thickness and internal relief (M1-M12: representative of CAD/CAM group, C1-C12: representative of conventional group). CAD/CAM milling machine (Cori TEC 340i; imes-icore GmbH, Eiterfeld, Germany) was used to fabricate the CAD/CAM group wax-patterns. The copings cast from 24 wax-patterns were cemented to the corresponding dies. For all the coping-die assemblies cross-sectional technique was used to evaluate the marginal and internal fit at 15 points. The Student’s t- test was used for statistical analysis (α=0.05). Results: The overall mean (SD) for absolute marginal discrepancy (AMD) was 254.46 (25.10) um for CAD/CAM group and 88.08(10.67) um for conventional group (control). The overall mean of internal gap total (IGT) was 110.77(5.92) um for CAD/CAM group and 76.90 (10.17) um for conventional group. The Student’s t-test revealed significant differences between 2 groups. Marginal and internal gaps were found to be significantly higher at all measured areas in CAD/CAM group than conventional group (p< 0.001). Conclusion: Within limitations of this study, conventional method of wax-pattern fabrication produced copings with significantly better marginal and internal fit than CAD/CAM (machine-milled) technique. All the factors for 2 groups were standardized except wax pattern fabrication technique, therefore

Epicuticular waxes on onion leaves and associated resistance to onion thrips

USDA-ARS?s Scientific Manuscript database

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...

Bacterial and primary production in the pelagic zone of the Kara Sea

NASA Astrophysics Data System (ADS)

Sazhin, A. F.; Romanova, N. D.; Mosharov, S. A.

2010-10-01

Data on the bacterial and primary production, which were obtained simultaneously for the same water samples, are presented for three regions of the Kara Sea. The samples were collected for the transect westwards of the Yamal Peninsula, along the St. Anna Trough, and the transect in Ob Bay. Direct counts of the DAPI-stained bacterial cells were performed. The bacterial production and grazing rates were determined using a direct method when metabolic inhibitors vancomycin and penicillin were added. The primary production rates were estimated using the 14C method. The average primary production was 112.6, 58.5, and 28.7 mg C m-2 day-1, and the bacterial production was 12.8, 48.9, and 81.6 mg C m-2 day-1 along the Yamal Peninsula, the St. Anna Trough, and Ob Bay, respectively. The average bacterial carbon demand was 34.6, 134.5, and 220.4 mg C m-2 day-1 for these regions, respectively. The data obtained lead us to conclude that the phytoplankton-synthesized organic matter is generally insufficient to satisfy the bacterial carbon demand and may be completely assimilated via the heterotrophic processes in the marine ecosystems. Therefore, the bacterial activity and, consequently, the amount of the synthesized biomass (i.e., the production) both depend directly on the phytoplankton’s condition and activity. We consider these relationships to be characteristics of the Kara Sea’s biota.

Bacterial and primary production in the Greenland Sea

NASA Astrophysics Data System (ADS)

Børsheim, Knut Yngve

2017-12-01

Bacterial production rates were measured in water profiles collected in the Greenland Sea and adjacent areas. Hydrography and nutrients throughout the water column were measured along 75°N from 12°W to 10°E at 20 km distance intervals. Net primary production rates from satellite sensed data were compared with literature values from 14C incubations and used for regional and seasonal comparisons. Maximum bacterial production rates were associated with the region close to the edge of the East Greenland current, and the rates decreased gradually towards the center of the Greenland Sea central gyre. Integrated over the upper 20 m the maximum bacterial production rate was 17.9 mmol C m- 2 day- 1, and east of the center of the gyre the average integrated rate was 4.6 mmol C m- 2 day- 1. It is hypothesized that high bacterial production rates in the western Greenland Sea were sustained by organic material carried from the Arctic Ocean by the East Greenland Current. The depth profiles of nitrate and phosphate were very similar both sides of the Arctic front, with 2% higher values between 500 m and 2000 m in the Arctic domain, and a N/P ratio of 13.6. The N/Si ratio varied by depth and region, with increasing silicate depletion from 1500 m depth to the surface. The rate of depletion from 1500 m depth to surface in the Atlantic domain was twice as high as in the Arctic domain. Net primary production rates in the area between the edge of the East Greenland current and the center of the Greenland Sea gyre was 96 mmol C m- 2 day- 1 at the time of the expedition in 2006, and 78 mmol C m- 2 day- 1 east of the center including the Atlantic domain. Annual net primary production estimated from satellite data in the Greenland Sea increased substantially in the period between 2003 and 2016, and the rate of increase was lowest close to the East Greenland Current.

Monoacylglycerols are components of root waxes and can be produced in the aerial cuticle by ectopic expression of a suberin-associated acyltransferase.

PubMed

Li, Yonghua; Beisson, Fred; Ohlrogge, John; Pollard, Mike

2007-07-01

The interface between plants and the environment is provided for aerial organs by epicuticular waxes that have been extensively studied. By contrast, little is known about the nature, biosynthesis, and role of waxes at the root-rhizosphere interface. Waxes isolated by rapid immersion of Arabidopsis (Arabidopsis thaliana) roots in organic solvents were rich in saturated C18-C22 alkyl esters of p-hydroxycinnamic acids, but also contained significant amounts of both alpha- and beta-isomers of monoacylglycerols with C22 and C24 saturated acyl groups and the corresponding free fatty acids. Production of these compounds in root waxes was positively correlated to the expression of sn-glycerol-3-P acyltransferase5 (GPAT5), a gene encoding an acyltransferase previously shown to be involved in aliphatic suberin synthesis. This suggests a direct metabolic relationship between suberin and some root waxes. Furthermore, when ectopically expressed in Arabidopsis, GPAT5 produced very-long-chain saturated monoacylglycerols and free fatty acids as novel components of cuticular waxes. The crystal morphology of stem waxes was altered and the load of total stem wax compounds was doubled, although the major components typical of the waxes found on wild-type plants decreased. These results strongly suggest that GPAT5 functions in vivo as an acyltransferase to a glycerol-containing acceptor and has access to the same pool of acyl intermediates and/or may be targeted to the same membrane domain as that of wax synthesis in aerial organs.

WAXS studies of the structural diversity of hemoglobin in solution.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makowski, L.; Bardhan, J.; Gore, D.

2011-01-01

Specific ligation states of hemoglobin are, when crystallized, capable of taking on multiple quaternary structures. The relationship between these structures, captured in crystal lattices, and hemoglobin structure in solution remains uncertain. Wide-angle X-ray solution scattering (WAXS) is a sensitive probe of protein structure in solution that can distinguish among similar structures and has the potential to contribute to these issues. We used WAXS to assess the relationships among the structures of human and bovine hemoglobins in different liganded forms in solution. WAXS data readily distinguished among the various forms of hemoglobins. WAXS patterns confirm some of the relationships among hemoglobinmore » structures that have been defined through crystallography and NMR and extend others. For instance, methemoglobin A in solution is, as expected, nearly indistinguishable from HbCO A. Interestingly, for bovine hemoglobin, the differences between deoxy-Hb, methemoglobin and HbCO are smaller than the corresponding differences in human hemoglobin. WAXS data were also used to assess the spatial extent of structural fluctuations of various hemoglobins in solution. Dynamics has been implicated in allosteric control of hemoglobin, and increased dynamics has been associated with lowered oxygen affinity. Consistent with that notion, WAXS patterns indicate that deoxy-Hb A exhibits substantially larger structural fluctuations than HbCO A. Comparisons between the observed WAXS patterns and those predicted on the basis of atomic coordinate sets suggest that the structures of Hb in different liganded forms exhibit clear differences from known crystal structure.« less

Investigation of liquid wax components of Egyptian jojoba seeds.

PubMed

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

2009-01-01

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

Equisetum species show uniform epicuticular wax structures but diverse composition patterns

PubMed Central

Brune, Thomas; Haas, Klaus

2011-01-01

Background and aims Only few data on the epicuticular waxes (EWs) of horsetails are available. This contribution therefore focuses on the wax micromorphology and chemical composition of Equisetum species of the subgenera Equisetum and Hippochaete. Methodology Distribution patterns and structural details of EW on the shoots were studied by scanning electron microscopy. After extraction with chloroform, the chemical composition of wax isolates was analysed by gas chromatography. Principal results Epicuticular wax crystals were non-oriented platelets or membraneous platelets. They were usually located on subsidiary cells of stomata and adjacent cells. Other parts of the shoots were covered mainly with a smooth wax film or small granules only. The chemical constituents found were alkanes, esters, aldehydes, primary alcohols and free fatty acids in a range of C20–C36 (in esters C36–C56). All species of the subgenus Hippochaete showed a similar pattern of fractions with high percentages of alkanes and aldehydes, whereas the subgenus Equisetum species had distinctly different wax compositions. Extracts from the internodes—surfaces without well-developed EW crystals and only few stomata—showed the lowest contents of aldehydes. Conclusions The covering with EW crystals will provide unhindered gas exchange and, combined with intracuticular wax, may prevent excess water loss during winter in the evergreen shoots of the subgenus Hippochaete. The results indicate that the Equisetum wax micromorphology and biosynthesis are comparable to EW of other pteridophyte classes and mosses. PMID:22476480

Pickering emulsions stabilized by paraffin wax and Laponite clay particles.

PubMed

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

2009-08-01

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

Coating green slash asphalt and wax prevent drying

Treesearch

Harry E. Schimke; Ronald H. Dougherty

1967-01-01

Dry logging slash has been successfully kept dry for later burning by spraying it with asphalt and wax emulsions. The same treatments were tried on green slash. Tests made by applying SS-1 grade asphalt emulsion and a lumber wax on green slash showed that these protective coatings prevented the slash from drying satisfactorily.

Spruce budworm feeding and oviposition are stimulated by monoterpenes in white spruce epicuticular waxes.

PubMed

Ennis, Darragh; Despland, Emma; Chen, Fei; Forgione, Pat; Bauce, Eric

2017-02-01

Monoterpenes, source of the distinctive odor of conifers, are generally considered plant defensive compounds. However, they are also known to act as long-range insect attractants, as they are volatile and permeate forest airspaces. Moreover, they are lipid soluble and can be absorbed into plant epicuticular waxes. We test their role in short-range host plant choice by both adult females and larvae of a folivorous forest pest (Choristoneura fumiferana). We conducted laboratory assays testing the responses of Eastern spruce budworm to an artificial monoterpene mix (α-pinene, β-pinene, limonene, myrcene) and to white spruce (Picea glauca) epicuticular waxes in closed arenas. Ovipositing females preferred filter paper discs treated with P. glauca waxes to controls, and preferred the waxes + monoterpenes treatment to waxes alone. However, females showed no preference between the monoterpene-treated disc and the control when presented without waxes. Feeding larvae prefered wax discs to control discs. They also consumed discs treated with realistic monoterpene concentrations and wax preferentially over wax-only discs, but showed no preference between extremely high monoterpene concentrations and wax-only controls. In an insect-free assay, P. glauca epicuticular wax decreased monoterpene volatilization. These results suggest that P. glauca waxes and realistic concentrations of monoterpenes are stimulatory to both egg-laying females and feeding larvae, and that their effects are synergistic. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Reproduction and subchronic feeding study of carnauba wax in rats.

PubMed

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

1983-02-01

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

Uncovered secret of a Vasseur-Tramond wax model.

PubMed

Pastor, J F; Gutiérrez, B; Montes, J M; Ballestriero, R

2016-01-01

The technique of anatomical wax modelling reached its heyday in Italy during the 18th century, through a fruitful collaboration between sculptors and anatomists. It soon spread to other countries, and prestigious schools were created in England, France, Spain and Austria. Paris subsequently replaced Italy as the major centre of manufacture, and anatomical waxes were created there from the mid-19th century in workshops such as that of Vasseur-Tramond. This workshop began to sell waxes to European Faculties of Medicine and Schools of Surgery around 1880. Little is known of the technique employed in the creation of such artefacts as this was deemed a professional secret. To gain some insight into the methods of construction, we have studied a Vasseur-Tramond wax model in the Valladolid University Anatomy Museum, Spain, by means of multi-slice computerised tomography and X-ray analysis by means of environmental scanning electron microscopy. Scanning electron microscopy was used to examine the hair. These results have revealed some of the methods used to make these anatomical models and the materials employed. © 2015 Anatomical Society.

Wax encapsulation of water-soluble compounds for application in foods.

PubMed

Mellema, M; Van Benthum, W A J; Boer, B; Von Harras, J; Visser, A

2006-11-01

Water-soluble ingredients have been successfully encapsulated in wax using two preparation techniques. The first technique ('solid preparation') leads to relatively large wax particles. The second technique ('liquid preparation') leads to relatively small wax particles immersed in vegetable oil. On the first technique: stable encapsulation of water-soluble colourants (dissolved at low concentration in water) has been achieved making use of beeswax and PGPR. The leakage from the capsules, for instance of size 2 mm, is about 30% after 16 weeks storage in water at room temperature. To form such capsules a minimum wax mass of 40% relative to the total mass is needed. High amounts of salt or acids at the inside water phase causes more leaking, probably because of the osmotic pressure difference. Osmotic matching of inner and outer phase can lead to a dramatic reduction in leakage. Fat capsules are less suitable to incorporate water soluble colourants. The reason for this could be a difference in crystal structure (fat is less ductile and more brittle). On the second technique: stable encapsulation of water-soluble colourants (encapsulated in solid wax particles) has been achieved making use of carnauba wax. The leakage from the capsules, for instance of size 250 mm, is about 40% after 1 weeks storage in water at room temperature.

Engineering microbial hosts for production of bacterial natural products.

PubMed

Zhang, Mingzi M; Wang, Yajie; Ang, Ee Lui; Zhao, Huimin

2016-08-27

Covering up to end 2015Microbial fermentation provides an attractive alternative to chemical synthesis for the production of structurally complex natural products. In most cases, however, production titers are low and need to be improved for compound characterization and/or commercial production. Owing to advances in functional genomics and genetic engineering technologies, microbial hosts can be engineered to overproduce a desired natural product, greatly accelerating the traditionally time-consuming strain improvement process. This review covers recent developments and challenges in the engineering of native and heterologous microbial hosts for the production of bacterial natural products, focusing on the genetic tools and strategies for strain improvement. Special emphasis is placed on bioactive secondary metabolites from actinomycetes. The considerations for the choice of host systems will also be discussed in this review.

Studies on the structure of the plant wax nonacosan-10-ol, the main component of epicuticular wax conifers.

PubMed

Matas, Antonio J; Sanz, María José; Heredia, Antonio

2003-11-01

The main component presents in the epicuticular waxes of needles of Pinus halepensis and the most of conifers, the secondary alcohol nonacosan-10-ol, has been investigated by X-ray diffraction and differential scanning calorimetry. The results obtained from these physical techniques permitted to establish a definitive structural model of the molecular arrangement of this wax, basically in good agreement with the model formulated by other authors from theoretical formulations. Biological implications of the proposed structure have been also formulated.

Crystal morphology of sunflower wax in soybean oil organogel

USDA-ARS?s Scientific Manuscript database

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 ...

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

NASA Astrophysics Data System (ADS)

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.

Novel bone wax based on poly(ethylene glycol)-calcium phosphate cement mixtures.

PubMed

Brückner, Theresa; Schamel, Martha; Kübler, Alexander C; Groll, Jürgen; Gbureck, Uwe

2016-03-01

Classic bone wax is associated with drawbacks such as the risk of infection, inflammation and hindered osteogenesis. Here, we developed a novel self-setting bone wax on the basis of hydrophilic poly(ethylene glycol) (PEG) and hydroxyapatite (HA) forming calcium phosphate cement (CPC), to overcome the problems that are linked to the use of conventional beeswax systems. Amounts of up to 10 wt.% of pregelatinized starch were additionally supplemented as hemostatic agent. After exposure to a humid environment, the PEG phase dissolved and was exchanged by penetrating water that interacted with the HA precursor (tetracalcium phosphate (TTCP)/monetite) to form highly porous, nanocrystalline HA via a dissolution/precipitation reaction. Simultaneously, pregelatinized starch could gel and supply the bone wax with liquid sealing features. The novel bone wax formulation was found to be cohesive, malleable and after hardening under aqueous conditions, it had a mechanical performance (∼2.5 MPa compressive strength) that is comparable to that of cancellous bone. It withstood systolic blood pressure conditions for several days and showed antibacterial properties for almost one week, even though 60% of the incorporated drug vancomycin hydrochloride was already released after 8h of deposition by diffusion controlled processes. The study investigated the development of alternative bone waxes on the basis of a hydroxyapatite (HA) forming calcium phosphate cement (CPC) system. Conventional bone waxes are composed of non-biodegradable beeswax/vaseline mixtures that are often linked to infection, inflammation and hindered osteogenesis. We combined the usage of bioresorbable polymers, the supplementation with hemostatic agents and the incorporation of a mineral component to overcome those drawbacks. Self-setting CPC precursors (tetracalcium phosphate (TTCP), monetite) were embedded in a resorbable matrix of poly(ethylene glycol) (PEG) and supplemented with pregelatinized starch. This

Accuracy of Digitally Fabricated Wax Denture Bases and Conventional Completed Complete Dentures.

PubMed

Stawarczyk, Bogna; Lümkemann, Nina; Eichberger, Marlis; Wimmer, Timea

2017-12-19

The purpose of this investigation was to analyze the accuracy of digitally fabricated wax trial dentures and conventionally finalized complete dentures in comparison to a surface tessellation language (STL)-dataset. A generated data set for the denture bases and the tooth sockets was used, converted into STL-format, and saved as reference. Five mandibular and 5 maxillary denture bases were milled from wax blanks and denture teeth were waxed into their tooth sockets. Each complete denture was checked on fit, waxed onto the dental cast, and digitized using an optical laboratory scanning device. The complete dentures were completed conventionally using the injection method, finished, and scanned. The resulting STL-datasets were exported into the three-dimensional (3D) software GOM Inspect. Each of the 5 mandibular and 5 maxillary complete dentures was aligned with the STL- and the wax trial denture dataset. Alignment was performed based on a best-fit algorithm. A three-dimensional analysis of the spatial divergences in x -, y - and z -axes was performed by the 3D software and visualized in a color-coded illustration. The mean positive and negative deviations between the datasets were calculated automatically. In a direct comparison between maxillary wax trial dentures and complete dentures, complete dentures showed higher deviations from the STL-dataset than the wax trial dentures. The deviations occurred in the area of the teeth as well as in the distal area of the denture bases. In contrast, the highest deviations in both the mandibular wax trial dentures and the mandibular complete dentures were observed in the distal area. The complete dentures showed higher deviations on the occlusal surfaces of the teeth compared to the wax dentures. Computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated wax dentures exhibited fewer deviations from the STL-reference than the complete dentures. The deviations were significantly greater in the vicinity of the

Epicuticular wax on cherry laurel (Prunus laurocerasus) leaves does not constitute the cuticular transpiration barrier.

PubMed

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.

Comparative Analyses of Cuticular Waxes on Various Organs of Potato (Solanum tuberosum L.).

PubMed

Guo, Yanjun; Jetter, Reinhard

2017-05-17

Complex mixtures of cuticular waxes coat plant surfaces to seal them against environmental stresses, with compositions greatly varying between species and possibly organs. This paper reports comprehensive analyses of the waxes on both above- and below-ground organs of potato, where total wax coverages varied between petals (2.6 μg/cm 2 ), leaves, stems, and tubers (1.8-1.9 μg/cm 2 ), and rhizomes (1.1 μg/cm 2 ). The wax mixtures on above-ground organs were dominated by alkanes, occurring in homologous series of isomeric C 25 -C 35 n-alkanes, C 25 -C 35 2-methylalkanes, and C 26 -C 34 3-methylalkanes. In contrast, below-ground organs had waxes rich in monoacylglycerols (C 22 -C 28 acyls) and C 18 -C 30 alkyl ferulates, together with fatty acids (rhizomes) or primary alcohols (tubers). The organ-specific wax coverages, compound class distribution, and chain length profiles suggest highly regulated activities of wax biosynthesis enzymes, likely related to organ-specific ecophysiological functions.

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

PubMed

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.

Development and Performance Evaluation of Image-Based Robotic Waxing System for Detailing Automobiles

PubMed Central

Hsu, Bing-Cheng

2018-01-01

Waxing is an important aspect of automobile detailing, aimed at protecting the finish of the car and preventing rust. At present, this delicate work is conducted manually due to the need for iterative adjustments to achieve acceptable quality. This paper presents a robotic waxing system in which surface images are used to evaluate the quality of the finish. An RGB-D camera is used to build a point cloud that details the sheet metal components to enable path planning for a robot manipulator. The robot is equipped with a multi-axis force sensor to measure and control the forces involved in the application and buffing of wax. Images of sheet metal components that were waxed by experienced car detailers were analyzed using image processing algorithms. A Gaussian distribution function and its parameterized values were obtained from the images for use as a performance criterion in evaluating the quality of surfaces prepared by the robotic waxing system. Waxing force and dwell time were optimized using a mathematical model based on the image-based criterion used to measure waxing performance. Experimental results demonstrate the feasibility of the proposed robotic waxing system and image-based performance evaluation scheme. PMID:29757940

Development and Performance Evaluation of Image-Based Robotic Waxing System for Detailing Automobiles.

PubMed

Lin, Chi-Ying; Hsu, Bing-Cheng

2018-05-14

Waxing is an important aspect of automobile detailing, aimed at protecting the finish of the car and preventing rust. At present, this delicate work is conducted manually due to the need for iterative adjustments to achieve acceptable quality. This paper presents a robotic waxing system in which surface images are used to evaluate the quality of the finish. An RGB-D camera is used to build a point cloud that details the sheet metal components to enable path planning for a robot manipulator. The robot is equipped with a multi-axis force sensor to measure and control the forces involved in the application and buffing of wax. Images of sheet metal components that were waxed by experienced car detailers were analyzed using image processing algorithms. A Gaussian distribution function and its parameterized values were obtained from the images for use as a performance criterion in evaluating the quality of surfaces prepared by the robotic waxing system. Waxing force and dwell time were optimized using a mathematical model based on the image-based criterion used to measure waxing performance. Experimental results demonstrate the feasibility of the proposed robotic waxing system and image-based performance evaluation scheme.

Marginal adaptation of four inlay casting waxes on stone, titanium, and zirconia dies.

PubMed

Michalakis, Konstantinos X; Kapsampeli, Vassiliki; Kitsou, Aikaterini; Kirmanidou, Yvone; Fotiou, Anna; Pissiotis, Argirios L; Calvani, Pasquale Lino; Hirayama, Hiroshi; Kudara, Yukio

2014-07-01

Different inlay casting waxes do not produce copings with satisfactory marginal accuracy when used on different die materials. The purpose of this study was to evaluate the marginal accuracy of 4 inlay casting waxes on stone dies and titanium and zirconia abutments and to correlate the findings with the degree of wetting between the die specimens and the inlay casting waxes. The inlay casting waxes tested were Starwax (Dentaurum), Unterziehwachs (Bredent), SU Esthetic wax (Schuler), and Sculpturing wax (Renfert). The marginal opening of the waxes was measured with a stereomicroscope on high-strength stone dies and on titanium and zirconia abutments. Photographic images were obtained, and the mean marginal opening for each specimen was calculated. A total of 1440 measurements were made. Wetting between die materials and waxes was determined after fabricating stone, titanium, and zirconia rectangular specimens. A calibrated pipette was used to place a drop of molten wax onto each specimen. The contact angle was calculated with software after an image of each specimen had been made with a digital camera. Collected data were subjected to a 2-way analysis of variance (α=.05). Any association between marginal accuracy and wetting of different materials was found by using the Pearson correlation. The wax factor had a statistically significant effect both on the marginal discrepancy (F=158.31, P<.001) and contact angle values (F=68.09, P<.001). A statistically significant effect of the die material factor both on the marginal adaptation (F=503.47, P<.001) and contact angle values (F=585.02, P<.001) was detected. A significant correlation between the marginal accuracy and the contact angle values (Pearson=0.881, P=.01) was also found. Stone dies provided wax copings with the best marginal integrity, followed by titanium and zirconia abutments. Unterziehwachs (Bredent), wax produced the best marginal adaptation on different die materials. A significant correlation was found

Production and Status of Bacterial Cellulose in Biomedical Engineering

PubMed Central

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.

High-level accumulation of oleyl oleate in plant seed oil by abundant supply of oleic acid substrates to efficient wax ester synthesis enzymes.

PubMed

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

Effects of cuticular wax on the postharvest quality of blueberry fruit.

PubMed

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.

Composition and morphology of cuticular wax in blueberry (Vaccinium spp.) fruits.

PubMed

Chu, Wenjing; Gao, Haiyan; Cao, Shifeng; Fang, Xiangjun; Chen, Hangjun; Xiao, Shangyue

2017-03-15

The chemical composition and morphology of cuticular wax in mature fruit of nine blueberry cultivars were investigated using gas chromatography-mass spectrometry (GC-MS) and scanning electron microscope (SEM). Triterpenoids and β-diketones were the most prominent compounds, accounting for on average 64.2% and 16.4% of the total wax, respectively. Ursolic or oleanolic acid was identified as the most abundant triterpenoids differing in cultivars. Two β-diketones, hentriacontan-10,12-dione and tritriacontan-12,14-dione, were detected in cuticular wax of blueberry fruits for the first time. Notably, hentriacontan-10,12-dione and tritriacontan-12,14-dione were only detected in highbush (V. corymbosum) and rabbiteye (V. ashei) blueberries, respectively. The results of SEM showed that a large amount of tubular wax deposited on the surface of blueberry fruits. There was no apparent difference in wax morphology among the nine cultivars. Copyright © 2016 Elsevier Ltd. All rights reserved.

Wax Layers on Cosmos bipinnatus Petals Contribute Unequally to Total Petal Water Resistance1[OPEN

PubMed Central

Buschhaus, Christopher; Hager, Dana; Jetter, Reinhard

2015-01-01

Cuticular waxes coat all primary aboveground plant organs as a crucial adaptation to life on land. Accordingly, the properties of waxes have been studied in much detail, albeit with a strong focus on leaf and fruit waxes. Flowers have life histories and functions largely different from those of other organs, and it remains to be seen whether flower waxes have compositions and physiological properties differing from those on other organs. This work provides a detailed characterization of the petal waxes, using Cosmos bipinnatus as a model, and compares them with leaf and stem waxes. The abaxial petal surface is relatively flat, whereas the adaxial side consists of conical epidermis cells, rendering it approximately 3.8 times larger than the projected petal area. The petal wax was found to contain unusually high concentrations of C22 and C24 fatty acids and primary alcohols, much shorter than those in leaf and stem waxes. Detailed analyses revealed distinct differences between waxes on the adaxial and abaxial petal sides and between epicuticular and intracuticular waxes. Transpiration resistances equaled 3 × 104 and 1.5 × 104 s m−1 for the adaxial and abaxial surfaces, respectively. Petal surfaces of C. bipinnatus thus impose relatively weak water transport barriers compared with typical leaf cuticles. Approximately two-thirds of the abaxial surface water barrier was found to reside in the epicuticular wax layer of the petal and only one-third in the intracuticular wax. Altogether, the flower waxes of this species had properties greatly differing from those on vegetative organs. PMID:25413359

Bacterial secondary production on vascular plant detritus: relationships to detritus composition and degradation rate.

PubMed Central

Moran, M A; Hodson, R E

1989-01-01

Bacterial production at the expense of vascular plant detritus was measured for three emergent plant species (Juncus effusus, Panicum hemitomon, and Typha latifolia) degrading in the littoral zone of a thermally impacted lake. Bacterial secondary production, measured as tritiated thymidine incorporation into DNA, ranged from 0.01 to 0.81 microgram of bacterial C mg of detritus-1 day-1. The three plant species differed with respect to the amount of bacterial productivity they supported per milligram of detritus, in accordance with the predicted biodegradability of the plant material based on initial nitrogen content, lignin content, and C/N ratio. Bacterial production also varied throughout the 22 weeks of in situ decomposition and was positively related to the nitrogen content and lignin content of the remaining detritus, as well as to the temperature of the lake water. Over time, production was negatively related to the C/N ratio and cellulose content of the degrading plant material. Bacterial production on degrading plant material was also calculated on the basis of plant surface area and ranged from 0.17 to 1.98 micrograms of bacterial C cm-2 day-1. Surface area-based calculations did not correlate well with either initial plant composition or changing composition of the remaining detritus during decomposition. The rate of bacterial detritus degradation, calculated from measured production of surface-attached bacteria, was much lower than the actual rate of weight loss of plant material. This discrepancy may be attributable to the importance of nonbacterial organisms in the degradation and loss of plant material from litterbags or to the microbially mediated solubilization of particulate material prior to bacterial utilization, or both. PMID:2802603

Comparative Evaluation of Rice Bran Wax as an Ointment Base with Standard Base

PubMed Central

Sabale, Vidya; Sabale, P. M.; Lakhotiya, C. L.

2009-01-01

Waxes have been used in many cosmetic preparations and pharmaceuticals as formulation aids. Rice bran wax is a byproduct of rice bran oil industry. Present investigation has been aimed to explore the possible utility of rice bran wax as ointment base compared to standard base. The rice bran wax obtained, purified and its physicochemical characteristics were determined. Ointment base acts as a carrier for medicaments. The ointment base composition determines not only the extent of penetration but also controls the transfer of medicaments from the base to the body tissues. Rice bran wax base was compared with standard base for appearance, spreadability, water number, wash ability and diffusibility. The results show that rice bran wax acts as an ointment base as far as its pharmaceutical properties are concerned and it could effectively replace comparatively costlier available ointment bases. PMID:20177466

DDT Behavior of Waxed Mixtures of RDX, HMX, and Tetryl

DTIC Science & Technology

1977-10-18

HMX (689*; Class A, 6 ’ 200p), RDX (659; Class E, 6 P 15p), tetryl (812; 6 s 470p), carnauba wax (134; 6 r 125p). The mixing procedure was that used...NSWC/WOL TR 77-96 O DDT BEHAVIOR OF WAXED MIXTURES OF " RDX, HMX, AND TETRYL BY DONNA PRICE and RICHARD R. BERNECKER RESEARCH AND TECHNOLOGY...BEFORE COMPLETING FORM RY PORT NUM ER 2. GOVT ACCESSION No. 3. RECIPIENT’S CATALOG NUMBER S. TYPE OF REPORT & PERIOD COVERED PDT Behavior of Waxed Mixtures

Research on influence of wax deposition on flow state in coiled tubing with cable inside

NASA Astrophysics Data System (ADS)

Ye, Qinyou; Xian, Linyun; Zhang, Fan; Yu, Han; Li, Xiao

2018-04-01

The effect of the morphology of the wax on the flow state in the coiled tubing with concentric cable was studied by numerical simulation. The results show that flow stream lines of crude oil are parallel to each other in the tubing with no waxing. It is disturbed at the two ends of wax deposition, transvers flow is formed at ends of wax and flow oil is speeded up in gap between wax and cable, friction pressure loss is then increased. This kind of influence becomes more serious with the increase of wax deposition proportion and thickness. An equivalent thickness is proposed to incorporate the influence of wax deposition proportion, length and thickness. With this parameter, a model is developed to calculate the pressure loss induced by wax on the base of concentric model, which can be used conveniently in engineering.

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

USDA-ARS?s Scientific Manuscript database

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

Anatomical models and wax Venuses: art masterpieces or scientific craft works?

PubMed Central

Ballestriero, R

2010-01-01

The art of wax modelling has an ancient origin but rose to prominence in 14th century Italy with the cult of votive artefacts. With the advent of Neoclassicism this art, now deemed repulsive, continued to survive in a scientific environment, where it flourished in the study of normal and pathological anatomy, obstetrics, zoology and botany. The achievement of having originated the creation of anatomical models in coloured wax must be ascribed to a joint effort undertaken by the Sicilian wax modeller Gaetano Giulio Zumbo and the French surgeon Guillaume Desnoues in the late 17th century. Interest in anatomical wax models spread throughout Europe during the 18th century, first in Bologna with Ercole Lelli, Giovanni Manzolini and Anna Morandi, and then in Florence with Felice Fontana and Clemente Susini. In England, the art of anatomical ceroplastics was brought to London from Florence by the sculptor Joseph Towne. Throughout the centuries many anatomical artists preferred this material due to the remarkable mimetic likeness obtained, far surpassing any other material. Independent of the material used, whether wood, wax or clay, anatomical models were always considered merely craft works confined to hospitals or faculties of medicine and have survived to this day only because of their scientific interest. Italian and English waxes are stylistically different but the remarkable results obtained by Susini and Towne, and the fact that some contemporary artists are again representing anatomical wax bodies in their works, makes the border that formerly separated art and craft indistinguishable. PMID:20002228

Anatomical models and wax Venuses: art masterpieces or scientific craft works?

PubMed

Ballestriero, R

2010-02-01

The art of wax modelling has an ancient origin but rose to prominence in 14th century Italy with the cult of votive artefacts. With the advent of Neoclassicism this art, now deemed repulsive, continued to survive in a scientific environment, where it flourished in the study of normal and pathological anatomy, obstetrics, zoology and botany. The achievement of having originated the creation of anatomical models in coloured wax must be ascribed to a joint effort undertaken by the Sicilian wax modeller Gaetano Giulio Zumbo and the French surgeon Guillaume Desnoues in the late 17th century. Interest in anatomical wax models spread throughout Europe during the 18th century, first in Bologna with Ercole Lelli, Giovanni Manzolini and Anna Morandi, and then in Florence with Felice Fontana and Clemente Susini. In England, the art of anatomical ceroplastics was brought to London from Florence by the sculptor Joseph Towne. Throughout the centuries many anatomical artists preferred this material due to the remarkable mimetic likeness obtained, far surpassing any other material. Independent of the material used, whether wood, wax or clay, anatomical models were always considered merely craft works confined to hospitals or faculties of medicine and have survived to this day only because of their scientific interest. Italian and English waxes are stylistically different but the remarkable results obtained by Susini and Towne, and the fact that some contemporary artists are again representing anatomical wax bodies in their works, makes the border that formerly separated art and craft indistinguishable.

The Effect of Ambient Ozone on Unsaturated Tear Film Wax Esters.

PubMed

Paananen, Riku O; Rantamäki, Antti H; Parshintsev, Jevgeni; Holopainen, Juha M

2015-12-01

Tear film lipid layer (TFLL) is constantly exposed to reactive ozone in the surrounding air, which may have detrimental effects on ocular health. Behenyl oleate (BO), a representative tear film wax ester, was used to study the reaction with ozone at the air-water interface. Time-dependent changes in mean molecular area of BO monolayers were measured at different ozone concentrations and surface pressures. In addition, the effect of ascorbic acid on the reaction rate was determined. Reaction was followed using thin-layer chromatography and reaction products were identified using liquid chromatography-electrospray ionization mass spectrometry (LC-MS). Tear fluid samples from healthy subjects were analyzed with LC-MS for any ozonolysis reaction products. Behenyl oleate was found to undergo rapid ozonolysis at the air-water interface at normal indoor ozone concentrations. The reaction was observed as an initial expansion followed by a contraction of the film area. Ascorbic acid was found to decrease the rate of ozonolysis. Main reaction products were identified as behenyl 9-oxononanoate and behenyl 8-(5-octyl-1,2,4-trioxolan-3-yl)octanoate. Similar ozonolysis products were not detected in the tear fluid samples. At the air-water interface, unsaturated wax esters react readily with ozone in ambient air. However, no signs of ozonolysis products were found in the tear fluid. This is most likely due to the antioxidant systems present in tear fluid. Last, the results show that ozonolysis needs to be controlled in future surface chemistry studies on tear film lipids.

Feasibility study for wax deposition imaging in oil pipelines by PGNAA technique.

PubMed

Cheng, Can; Jia, Wenbao; Hei, Daqian; Wei, Zhiyong; Wang, Hongtao

2017-10-01

Wax deposition in pipelines is a crucial problem in the oil industry. A method based on the prompt gamma-ray neutron activation analysis technique was applied to reconstruct the image of wax deposition in oil pipelines. The 2.223MeV hydrogen capture gamma rays were used to reconstruct the wax deposition image. To validate the method, both MCNP simulation and experiments were performed for wax deposited with a maximum thickness of 20cm. The performance of the method was simulated using the MCNP code. The experiment was conducted with a 252 Cf neutron source and a LaBr 3 : Ce detector. A good correspondence between the simulations and the experiments was observed. The results obtained indicate that the present approach is efficient for wax deposition imaging in oil pipelines. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-Biofilm Performance of Three Natural Products against Initial Bacterial Attachment

PubMed Central

Salta, Maria; Wharton, Julian A.; Dennington, Simon P.; Stoodley, Paul; Stokes, Keith R.

2013-01-01

Marine bacteria contribute significantly towards the fouling consortium, both directly (modern foul release coatings fail to prevent “slime” attachment) and indirectly (biofilms often excrete chemical cues that attract macrofouling settlement). This study assessed the natural product anti-biofilm performance of an extract of the seaweed, Chondrus crispus, and two isolated compounds from terrestrial sources, (+)-usnic acid and juglone, against two marine biofilm forming bacteria, Cobetia marina and Marinobacter hydrocarbonoclasticus. Bioassays were developed using quantitative imaging and fluorescent labelling to test the natural products over a range of concentrations against initial bacterial attachment. All natural products affected bacterial attachment; however, juglone demonstrated the best anti-biofilm performance against both bacterial species at a concentration range between 5–20 ppm. In addition, for the first time, a dose-dependent inhibition (hormetic) response was observed for natural products against marine biofilm forming bacteria. PMID:24192819

Development of formulations and processes to incorporate wax oleogels in ice cream.

PubMed

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®

Biogenic amine formation and bacterial contribution in Natto products.

PubMed

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

2012-12-01

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

Physico-chemical properties and efficacy of silk fibroin fabric coated with different waxes as wound dressing.

PubMed

Kanokpanont, Sorada; Damrongsakkul, Siriporn; Ratanavaraporn, Juthamas; Aramwit, Pornanong

2013-04-01

Silk fibroin (SF) has been widely used as a wound dressing material due to its suitable physical and biological characteristics. In this study, a non-adhesive wound dressing which applies to cover the wound surface as an absorbent pad that would absorb wound fluid while accelerate wound healing was developed. The modification of SF fabrics by wax coating was purposed to prepare the non-adhesive wound dressing that is required in order to minimize pain and risk of repeated injury. SF woven fabrics were coated with different types of waxes including shellac wax, beeswax, or carnauba wax. Physical and mechanical properties of the wax-coated SF fabrics were characterized. It was clearly observed that all waxes could be successfully coated on the SF fabrics, possibly due to the hydrophobic interactions between hydrophobic domains of SF and waxes. The wax coating improved tensile modulus and percentage of elongation of the SF fabrics due to the denser structure and the thicker fibers coated. The in vitro degradation study demonstrated that all wax-coated SF fabrics remained up to 90% of their original weights after 7 weeks of incubation in lysozyme solution under physiological conditions. The wax coating did not affect the degradation behavior of the SF fabrics. A peel test of the wax-coated SF fabrics was carried out in the partial- and full-thickness wounds of porcine skin in comparison to that of the commercial wound dressing. Any wax-coated SF fabrics were less adhesive than the control, as confirmed by less number of cells attached and less adhesive force. This might be that the wax-coated SF fabrics showed the hydrophobic property, allowing the loosely adherence to the hydrophilic wound surface. In addition, the in vivo biocompatibility test of the wax-coated SF fabrics was performed in Sprague-Dawley rats with subcutaneous model. The irritation scores indicated that the carnauba wax-coated SF fabric was not irritant while the shellac wax or beeswax-coated SF

Method for construction of bacterial strains with increased succinic acid production

DOEpatents

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.

Anaerobic digestion of thermal-alkaline-pretreated cephalosporin bacterial residues for methane production.

PubMed

Li, Guixia; Zhong, Weizhang; Wang, Rui; Chen, Jiaqi; Li, Zaixing

2017-08-01

Optimum anaerobic conditions of cephalosporin bacterial residues after thermal-alkaline pretreatment were determined by orthogonal experiments. And through biochemical methane potential tests (BMPs) for cephalosporin bacterial residues, the ability for bacterial degradation of cephalosporin was also evaluated. The thermal-alkaline pretreatment with the optimum values of 6% NaOH at 105 °C for 15 min significantly improved digestion performance. With the thermal-alkaline pretreatment, the specific methane yield of the pretreated cephalosporin bacterial residue increased by 254.79% compared with that of the un-pretreated cephalosporin bacterial residue. The results showed that anaerobic digestion of thermal-alkaline-pretreated cephalosporin bacterial residues could be one of the options for efficient methane production and waste treatment. This work investigates the thermal-alkaline pretreatment of cephalosporin bacterial residues, which can increase their methane yield by 254.79% compared with no pretreatment. The digestion performance is significantly improved under the condition of 6% NaOH at 105 °C for 15 min. The results show that anaerobic digestion of thermal-alkaline-pretreated cephalosporin bacterial residues could be one of the options for efficient methane production and waste treatment.

Cuticular Waxes of Arabidopsis thaliana Shoots: Cell-Type-Specific Composition and Biosynthesis

PubMed Central

Hegebarth, Daniela; Jetter, Reinhard

2017-01-01

It is generally assumed that all plant epidermis cells are covered with cuticles, and the distinct surface geometries of pavement cells, guard cells, and trichomes imply functional differences and possibly different wax compositions. However, experiments probing cell-type-specific wax compositions and biosynthesis have been lacking until recently. This review summarizes new evidence showing that Arabidopsis trichomes have fewer wax compound classes than pavement cells, and higher amounts of especially long-chain hydrocarbons. The biosynthesis machinery generating this characteristic surface coating is discussed. Interestingly, wax compounds with similar, long hydrocarbon chains had been identified previously in some unrelated species, not all of them bearing trichomes. PMID:28686187

Expression of Arabidopsis SHN1 in Indian Mulberry (Morus indica L.) Increases Leaf Surface Wax Content and Reduces Post-harvest Water Loss

PubMed Central

Sajeevan, R. S.; Nataraja, Karaba N.; Shivashankara, K. S.; Pallavi, N.; Gurumurthy, D. S.; Shivanna, M. B.

2017-01-01

Mulberry (Morus species) leaf is the sole food for monophagous silkworms, Bombyx mori L. Abiotic stresses such as drought, salinity, and high temperature, significantly decrease mulberry productivity and post-harvest water loss from leaves influence silkworm growth and cocoon yield. Leaf surface properties regulate direct water loss through the cuticular layer. Leaf surface waxes, contribute for cuticular resistance and protect mesophyll cells from desiccation. In this study we attempted to overexpress AtSHN1, a transcription factor associated with epicuticular wax biosynthesis to increase leaf surface wax load in mulberry. Agrobacterium mediated in vitro transformation was carried out using hypocotyl and cotyledonary explants of Indian mulberry (cv. M5). Mulberry transgenic plants expressing AtSHN1 displayed dark green shiny appearance with increased leaf surface wax content. Scanning electron microscopy (SEM) and gas chromatograph–mass spectrometry (GC-MS) analysis showed change in pattern of surface wax deposition and significant change in wax composition in AtSHN1 overexpressors. Increased wax content altered leaf surface properties as there was significant difference in water droplet contact angle and diameter between transgenic and wild type plants. The transgenic plants showed significant improvement in leaf moisture retention capacity even 5 h after harvest and there was slow degradation of total buffer soluble protein in detached leaves compared to wild type. Silkworm bioassay did not indicate any undesirable effects on larval growth and cocoon yield. This study demonstrated that expression of AtSHN1, can increase surface wax load and reduce the post-harvest water loss in mulberry. PMID:28421085

Evolutionary conserved function of barley and Arabidopsis 3-KETOACYL-CoA SYNTHASES in providing wax signals for germination of powdery mildew fungi.

PubMed

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

2014-11-01

For plant pathogenic fungi, such as powdery mildews, that survive only on a limited number of host plant species, it is a matter of vital importance that their spores sense that they landed on the right spot to initiate germination as quickly as possible. We investigated a barley (Hordeum vulgare) mutant with reduced epicuticular leaf waxes on which spores of adapted and nonadapted powdery mildew fungi showed reduced germination. The barley gene responsible for the mutant wax phenotype was cloned in a forward genetic screen and identified to encode a 3-KETOACYL-CoA SYNTHASE (HvKCS6), a protein participating in fatty acid elongation and required for synthesis of epicuticular waxes. Gas chromatography-mass spectrometry analysis revealed that the mutant has significantly fewer aliphatic wax constituents with a chain length above C-24. Complementation of the mutant restored wild-type wax and overcame germination penalty, indicating that wax constituents less present on the mutant are a crucial clue for spore germination. Investigation of Arabidopsis (Arabidopsis thaliana) transgenic plants with sense silencing of Arabidopsis REQUIRED FOR CUTICULAR WAX PRODUCTION1, the HvKCS6 ortholog, revealed the same germination phenotype against adapted and nonadapted powdery mildew fungi. Our findings hint to an evolutionary conserved mechanism for sensing of plant surfaces among distantly related powdery mildews that is based on KCS6-derived wax components. Perception of such a signal must have been evolved before the monocot-dicot split took place approximately 150 million years ago. © 2014 American Society of Plant Biologists. All Rights Reserved.

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

PubMed

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

2016-02-01

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

Understanding wax screen-printing: a novel patterning process for microfluidic cloth-based analytical devices.

PubMed

Liu, Min; Zhang, Chunsun; Liu, Feifei

2015-09-03

In this work, we first introduce the fabrication of microfluidic cloth-based analytical devices (μCADs) using a wax screen-printing approach that is suitable for simple, inexpensive, rapid, low-energy-consumption and high-throughput preparation of cloth-based analytical devices. We have carried out a detailed study on the wax screen-printing of μCADs and have obtained some interesting results. Firstly, an analytical model is established for the spreading of molten wax in cloth. Secondly, a new wax screen-printing process has been proposed for fabricating μCADs, where the melting of wax into the cloth is much faster (∼5 s) and the heating temperature is much lower (75 °C). Thirdly, the experimental results show that the patterning effects of the proposed wax screen-printing method depend to a certain extent on types of screens, wax melting temperatures and melting time. Under optimized conditions, the minimum printing width of hydrophobic wax barrier and hydrophilic channel is 100 μm and 1.9 mm, respectively. Importantly, the developed analytical model is also well validated by these experiments. Fourthly, the μCADs fabricated by the presented wax screen-printing method are used to perform a proof-of-concept assay of glucose or protein in artificial urine with rapid high-throughput detection taking place on a 48-chamber cloth-based device and being performed by a visual readout. Overall, the developed cloth-based wax screen-printing and arrayed μCADs should provide a new research direction in the development of advanced sensor arrays for detection of a series of analytes relevant to many diverse applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Wax transfer printing to enable robust barrier definition in devices based on non-standard porous materials

NASA Astrophysics Data System (ADS)

To, Anthony; Downs, Corey; Fu, Elain

2017-05-01

Wax printing has become a common method of fabricating channels in cellulose-based microfluidic devices. However, a limitation of wax printing is that it is restricted to relatively thin, smooth substrates that are compatible with processing by a commercial wax printer. In the current report, we describe a simple patterning method that extends the utility of wax printers for creating hydrophobic barriers on non-standard porous substrates via a process called wax transfer printing. We demonstrate the use of multiple wax transfer cycles to create well-defined, robust, and reproducible barriers in a thick cellulose substrate that is not compatible with feeding through a wax printer. We characterize the method for (i) wax spreading within the substrate as a function of heating time, (ii) the ability to create functional barriers in a substrate, and (iii) reproducibility in line width.

21 CFR 178.3850 - Reinforced wax.

Code of Federal Regulations, 2010 CFR

2010-04-01

... component of articles intended for use in producing, manufacturing, packing, processing, transporting, or... Type II Polyethylene Rosins and rosin derivatives as provided in § 178.3870 Synthetic wax polymer as...

21 CFR 178.3850 - Reinforced wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... component of articles intended for use in producing, manufacturing, packing, processing, transporting, or... Type II Polyethylene Rosins and rosin derivatives as provided in § 178.3870 Synthetic wax polymer as...

Comparative analysis of surface wax in mature fruits between Satsuma mandarin (Citrus unshiu) and 'Newhall' navel orange (Citrus sinensis) from the perspective of crystal morphology, chemical composition and key gene expression.

PubMed

Wang, Jinqiu; Hao, Haohao; Liu, Runsheng; Ma, Qiaoli; Xu, Juan; Chen, Feng; Cheng, Yunjiang; Deng, Xiuxin

2014-06-15

Surface wax of mature Satsuma mandarin (Citrus unshiu) and 'Newhall' navel orange (Citrus sinensis) was analysed by crystal morphology, chemical composition, and gene expression levels. The epicuticular and total waxes of both citrus cultivars were mostly composed of aldehydes, alkanes, fatty acids and primary alcohols. The epicuticular wax accounted for 80% of the total wax in the Newhall fruits and was higher than that in the Satsuma fruits. Scanning electron microscopy showed that larger and more wax platelets were deposited on the surface of Newhall fruits than on the Satsuma fruits. Moreover, the expression levels of genes involved in the wax formation were consistent with the biochemical and crystal morphological analyses. These diversities of fruit wax between the two cultivars may contribute to the differences of fruit postharvest storage properties, which can provide important information for the production of synthetic wax for citrus fruits. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prediction of wax buildup in 24 inch cold, deep sea oil loading line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asperger, R.G.; Sattler, R.E.; Tolonen, W.J.

1981-10-01

When designing pipelines for cold environments, it is important to know how to predict potential problems due to wax deposition on the pipeline's inner surface. The goal of this work was to determine the rate of wax buildup and the maximum, equlibrium wax thickness for a North Sea field loading line. The experimental techniques and results used to evaluate the waxing potential of the crude oil (B) are described. Also, the theoretic model which was used for predicting the maximum wax deposit thickness in the crude oil (B) loading pipeline at controlled temperatures of 40 F (4.4 C) and 100more » F (38 C), is illustrated. Included is a recommendation of a procedure for using hot oil at the end of a tanker loading period in order to dewax the crude oil (B) line. This technique would give maximum heating of the pipeline and should be followed by shutting the hot oil into the pipeline at the end of the loading cycle which will provide a hot oil soaking to help soften existing wax. 14 references.« less

Bacterial cellulose production by Gluconacetobacter sp. PKY5 in a rotary biofilm contactor.

PubMed

Kim, Yong-Jun; Kim, Jin-Nam; Wee, Young-Jung; Park, Don-Hee; Ryu, Hwa-Won

2007-04-01

A rotary biofilm contactor (RBC) inoculated with Gluconacetobacter sp. RKY5 was used as a bioreactor for improved bacterial cellulose production. The optimal number of disk for bacterial cellulose production was found to be eight, at which bacterial cellulose and cell concentrations were 5.52 and 4.98 g/L. When the aeration rate was maintained at 1.25 vvm, bacterial cellulose and cell concentrations were maximized (5.67 and 5.25 g/L, respectively). The optimal rotation speed of impeller in RBC was 15 rpm. When the culture pH in RBC was not controlled during fermentation, the maximal amount of bacterial cellulose (5.53 g/L) and cells (4.91 g/L) was obtained. Under the optimized culture conditions, bacterial cellulose and cell concentrations in RBC reached to 6.17 and 5.58 g/L, respectively.

Bacterial Cellulose Production by Gluconacetobacter sp. RKY5 in a Rotary Biofilm Contactor

NASA Astrophysics Data System (ADS)

Kim, Yong-Jun; Kim, Jin-Nam; Wee, Young-Jung; Park, Don-Hee; Ryu, Hwa-Won

A rotary biofilm contactor (RBC) inoculated with Gluconacetobacter sp. RKY5 was used as a bioreactor for improved bacterial cellulose production. The optimal number of disk for bacterial cellulose production was found to be eight, at which bacterial cellulose and cell concentrations were 5.52 and 4.98 g/L. When the aeration rate was maintained at 1.25 vvm, bacterial cellulose and cell concentrations were maximized (5.67 and 5.25 g/L, respectively). The optimal rotation speed of impeller in RBC was 15 rpm. When the culture pH in RBC was not controlled during fermentation, the maximal amount of bacterial cellulose (5.53 g/L) and cells (4.91 g/L) was obtained. Under the optimized culture conditions, bacterial cellulose and cell concentrations in RBC reached to 6.17 and 5.58 g/L, respectively.

21 CFR 186.1555 - Japan wax.

Code of Federal Regulations, 2013 CFR

2013-04-01

... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan), and R. trichocarpa (China, Indo-China, India, and Japan). Japan wax is soluble in hot alcohol, benzene...

21 CFR 186.1555 - Japan wax.

Code of Federal Regulations, 2012 CFR

2012-04-01

... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan), and R. trichocarpa (China, Indo-China, India, and Japan). Japan wax is soluble in hot alcohol, benzene...

21 CFR 186.1555 - Japan wax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan), and R. trichocarpa (China, Indo-China, India, and Japan). Japan wax is soluble in hot alcohol, benzene...

Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent.

PubMed

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.

Subchronic feeding study of carnauba wax in beagle dogs.

PubMed

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

1983-02-01

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

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

PubMed

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

2016-06-01

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.

Electrochemical behaviors of wax-coated Li powder/Li 4Ti 5O 12 cells

NASA Astrophysics Data System (ADS)

Park, Han Eol; Seong, Il Won; Yoon, Woo Young

The wax-coated Li powder specimen was effectively synthesized using the drop emulsion technique (DET). The wax layer on the powder was verified by SEM, Focused Ion Beam (FIB), EDX and XPS. The porosity of a sintered wax-coated Li electrode was measured by linear sweep voltammetry (LSV) and compared with that of a bare, i.e., un-coated Li electrode. The electrochemical behavior of the wax-coated Li powder anode cell was examined by the impedance analysis and cyclic testing methods. The cyclic behavior of the wax-coated Li powder anode with the Li 4Ti 5O 12 (LTO) cathode cell was examined at a constant current density of 0.35 mA cm -2 with the cut-off voltages of 1.2-2.0 V at 25 °C. Over 90% of the initial capacity of the cell remained even after the 300th cycle. The wax-coated Li powder was confirmed to be a stable anode material.

A Novel Pathway for Triacylglycerol Biosynthesis Is Responsible for the Accumulation of Massive Quantities of Glycerolipids in the Surface Wax of Bayberry (Myrica pensylvanica) Fruit[OPEN

PubMed Central

Ohlrogge, John B.

2016-01-01

Bayberry (Myrica pensylvanica) fruits synthesize an extremely thick and unusual layer of crystalline surface wax that accumulates to 32% of fruit dry weight, the highest reported surface lipid accumulation in plants. The composition is also striking, consisting of completely saturated triacylglycerol, diacylglycerol, and monoacylglycerol with palmitate and myristate acyl chains. To gain insight into the unique properties of Bayberry wax synthesis, we examined the chemical and morphological development of the wax layer, monitored wax biosynthesis through [14C]-radiolabeling, and sequenced the transcriptome. Radiolabeling identified sn-2 monoacylglycerol as an initial glycerolipid intermediate. The kinetics of [14C]-DAG and [14C]-TAG accumulation and the regiospecificity of their [14C]-acyl chains indicated distinct pools of acyl donors and that final TAG assembly occurs outside of cells. The most highly expressed lipid-related genes were associated with production of cutin, whereas transcripts for conventional TAG synthesis were >50-fold less abundant. The biochemical and expression data together indicate that Bayberry surface glycerolipids are synthesized by a pathway for TAG synthesis that is related to cutin biosynthesis. The combination of a unique surface wax and massive accumulation may aid understanding of how plants produce and secrete non-membrane glycerolipids and also how to engineer alternative pathways for lipid production in non-seeds. PMID:26744217

RAPA: a novel in vitro method to evaluate anti-bacterial skin cleansing products.

PubMed

Ansari, S A; Gafur, R B; Jones, K; Espada, L A; Polefka, T G

2010-04-01

Development of efficacious anti-bacterial skin cleansing products has been limited by the availability of a pre-clinical (in vitro) method to predict clinical efficacy adequately. We report a simple and rapid method, designated as rapid agar plate assay (RAPA), that uses the bacteriological agar surface as a surrogate substrate for skin and combines elements of two widely used in vivo (clinical) methods (Agar Patch and Cup Scrub). To simulate the washing of the human hand or forearm skin with the test product, trypticase soy agar plates were directly washed with the test product and rinsed under running tap water. After air-drying the washed plates, test bacteria (Staphylococcus aureus or Escherichia coli) were applied and the plates were incubated at 37 degrees C for 18-24 h. Using S. aureus as the test organism, anti-bacterial bar soap containing triclocarbanilide showed a strong linear relationship (R(2) = 0.97) between bacterial dose and their per cent reduction. A similar dose-response relationship (R(2) = 0.96) was observed for anti-bacterial liquid hand soap against E. coli. RAPA was able to distinguish between anti-bacterial products based on the nature and level of actives in them. In limited comparative tests, results obtained by RAPA were comparable with the results obtained by clinical agar patch and clinical cup scrub methods. In conclusion, RAPA provides a simple, rugged and reproducible in vitro method for testing the relative efficacy of anti-bacterial skin cleansing products with a likelihood of comparable clinical efficacy. Further testing is warranted to improve the clinical predictability of this method.

Water vapor barrier and sorption properties of edible films from pullulan and rice wax.

USDA-ARS?s Scientific Manuscript database

Edible films were prepared by using various ratios of pullulan and rice wax. Freestanding composite films were obtained with up to 46.4% rice wax. Water vapor barrier properties of the film were improved with increased addition of rice wax. Moisture sorption isotherms were also studied to examine...

Gelling ability and crystal morphology of sunflower wax in soybean oil

USDA-ARS?s Scientific Manuscript database

Plant waxes can effectively form organogels with vegetable oils and these organogels have drawn considerable interests as alternatives to solid fats containing trans fats and saturated fats in margarines and spreads. Among them sunflower wax showed the most pronounced gelling ability. In an attempt ...

[Comparative adaptation of crowns of selective laser melting and wax-lost-casting method].

PubMed

Li, Guo-qiang; Shen, Qing-yi; Gao, Jian-hua; Wu, Xue-ying; Chen, Li; Dai, Wen-an

2012-07-01

To investigate the marginal adaptation of crowns fabricated by selective laser melting (SLM) and wax-lost-casting method, so as to provide an experimental basis for clinic. Co-Cr alloy full crown were fabricated by SLM and wax-lost-casting for 24 samples in each group. All crowns were cemented with zinc phosphate cement and cut along longitudinal axis by line cutting machine. The gap between crown tissue surface and die was measured by 6-point measuring method with scanning electron microscope (SEM). The marginal adaptation of crowns fabricated by SLM and wax-lost-casting were compared statistically. The gap between SLM crowns were (36.51 ± 2.94), (49.36 ± 3.31), (56.48 ± 3.35), (42.20 ± 3.60) µm, and wax-lost-casting crowns were (68.86 ± 5.41), (58.86 ± 6.10), (70.62 ± 5.79), (69.90 ± 6.00) µm. There were significant difference between two groups (P < 0.05). Co-Cr alloy full crown fabricated by wax-lost-casting method and SLM method provide acceptable marginal adaptation in clinic, and the marginal adaptation of SLM is better than that of wax-lost-casting method.

Accuracy of ringless casting and accelerated wax-elimination technique: a comparative in vitro study.

PubMed

Prasad, Rahul; Al-Keraif, Abdulaziz Abdullah; Kathuria, Nidhi; Gandhi, P V; Bhide, S V

2014-02-01

The purpose of this study was to determine whether the ringless casting and accelerated wax-elimination techniques can be combined to offer a cost-effective, clinically acceptable, and time-saving alternative for fabricating single unit castings in fixed prosthodontics. Sixty standardized wax copings were fabricated on a type IV stone replica of a stainless steel die. The wax patterns were divided into four groups. The first group was cast using the ringless investment technique and conventional wax-elimination method; the second group was cast using the ringless investment technique and accelerated wax-elimination method; the third group was cast using the conventional metal ring investment technique and conventional wax-elimination method; the fourth group was cast using the metal ring investment technique and accelerated wax-elimination method. The vertical marginal gap was measured at four sites per specimen, using a digital optical microscope at 100× magnification. The results were analyzed using two-way ANOVA to determine statistical significance. The vertical marginal gaps of castings fabricated using the ringless technique (76.98 ± 7.59 μm) were significantly less (p < 0.05) than those castings fabricated using the conventional metal ring technique (138.44 ± 28.59 μm); however, the vertical marginal gaps of the conventional (102.63 ± 36.12 μm) and accelerated wax-elimination (112.79 ± 38.34 μm) castings were not statistically significant (p > 0.05). The ringless investment technique can produce castings with higher accuracy and can be favorably combined with the accelerated wax-elimination method as a vital alternative to the time-consuming conventional technique of casting restorations in fixed prosthodontics. © 2013 by the American College of Prosthodontists.

Seasonal Bacterial Production in a Dimictic Lake as Measured by Increases in Cell Numbers and Thymidine Incorporation

PubMed Central

Lovell, Charles R.; Konopka, Allan

1985-01-01

Rates of primary and bacterial production in Little Crooked Lake were calculated from the rates of incorporation of H14CO3− and [methyl-3H]thymidine, respectively. Growth rates of bacteria in diluted natural samples were determined for epilimnetic and metalimnetic bacterial populations during the summers of 1982 and 1983. Exponential growth was observed in these diluted samples, with increases in cell numbers of 30 to 250%. No lag was observed in bacterial growth in 14 of 16 experiments. Correlation of bacterial growth rates to corresponding rates of thymidine incorporation by natural samples produced a conversion factor of 2.2 × 1018 cells produced per mole of thymidine incorporated. The mass of the average bacterial cell in the lake was 1.40 × 10−14 ± 0.05 × 10−14 g of C cell−1. Doubling times of natural bacteria calculated from thymidine incorporation rates and in situ cell numbers ranged from 0.35 to 12.00 days (median, 1.50 days). Bacterial production amounted to 66.7 g of C m−2 from April through September, accounting for 29.4% of total (primary plus bacterial) production during this period. The vertical and seasonal distribution of bacterial production in Little Crooked Lake was strongly influenced by the distribution of primary production. From April through September 1983, the depth of maximum bacterial production rates in the water column was related to the depth of high rates of primary production. On a seasonal basis, primary production increased steadily from May through September, and bacterial production increased from May through August and then decreased in September. PMID:16346743

Bacterial Populations Associated with Smokeless Tobacco Products

PubMed Central

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

2016-01-01

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

Changes in Cuticular Wax Composition of Two Blueberry Cultivars during Fruit Ripening and Postharvest Cold Storage.

PubMed

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.

Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery.

PubMed

Attard, Thomas M; McElroy, Con Robert; Hunt, Andrew J

2015-07-31

To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be € 88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of € 10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM.

Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

PubMed Central

Attard, Thomas M.; McElroy, Con Robert; Hunt, Andrew J.

2015-01-01

To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of €10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM. PMID:26263976

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

PubMed Central

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

2014-01-01

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

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

PubMed

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 < 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.

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

PubMed

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

2018-03-13

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

Anatomically realistic ultrasound phantoms using gel wax with 3D printed moulds

NASA Astrophysics Data System (ADS)

Maneas, Efthymios; Xia, Wenfeng; Nikitichev, Daniil I.; Daher, Batol; Manimaran, Maniragav; Wong, Rui Yen J.; Chang, Chia-Wei; Rahmani, Benyamin; Capelli, Claudio; Schievano, Silvia; Burriesci, Gaetano; Ourselin, Sebastien; David, Anna L.; Finlay, Malcolm C.; West, Simeon J.; Vercauteren, Tom; Desjardins, Adrien E.

2018-01-01

Here we describe methods for creating tissue-mimicking ultrasound phantoms based on patient anatomy using a soft material called gel wax. To recreate acoustically realistic tissue properties, two additives to gel wax were considered: paraffin wax to increase acoustic attenuation, and solid glass spheres to increase backscattering. The frequency dependence of ultrasound attenuation was well described with a power law over the measured range of 3-10 MHz. With the addition of paraffin wax in concentrations of 0 to 8 w/w%, attenuation varied from 0.72 to 2.91 dB cm-1 at 3 MHz and from 6.84 to 26.63 dB cm-1 at 10 MHz. With solid glass sphere concentrations in the range of 0.025-0.9 w/w%, acoustic backscattering consistent with a wide range of ultrasonic appearances was achieved. Native gel wax maintained its integrity during compressive deformations up to 60%; its Young’s modulus was 17.4  ±  1.4 kPa. The gel wax with additives was shaped by melting and pouring it into 3D printed moulds. Three different phantoms were constructed: a nerve and vessel phantom for peripheral nerve blocks, a heart atrium phantom, and a placental phantom for minimally-invasive fetal interventions. In the first, nerves and vessels were represented as hyperechoic and hypoechoic tubular structures, respectively, in a homogeneous background. The second phantom comprised atria derived from an MRI scan of a patient with an intervening septum and adjoining vena cavae. The third comprised the chorionic surface of a placenta with superficial fetal vessels derived from an image of a post-partum human placenta. Gel wax is a material with widely tuneable ultrasound properties and mechanical characteristics that are well suited for creating patient-specific ultrasound phantoms in several clinical disciplines.

Discrimination Training and Formative Evaluation for Remediation in Basic Waxing Skills.

ERIC Educational Resources Information Center

Knight, G. William; Guenzel, Pamela

1990-01-01

An experimental group (n=6) of student dentists received discrimination training and self-evaluation exercises on 4 waxing projects and 4 handpiece projects over 13 hours. An equivalent "conventional" group (n=7) received verbal feedback with models on 7 waxing projects over 13 hours. The experimental group outperformed the conventional…

Major Evolutionary Trends in Hydrogen Isotope Fractionation of Vascular Plant Leaf Waxes

PubMed Central

Gao, Li; Edwards, Erika J.; Zeng, Yongbo; Huang, Yongsong

2014-01-01

Hydrogen isotopic ratios of terrestrial plant leaf waxes (δD) have been widely used for paleoclimate reconstructions. However, underlying controls for the observed large variations in leaf wax δD values in different terrestrial vascular plants are still poorly understood, hampering quantitative paleoclimate interpretation. Here we report plant leaf wax and source water δD values from 102 plant species grown in a common environment (New York Botanic Garden), chosen to represent all the major lineages of terrestrial vascular plants and multiple origins of common plant growth forms. We found that leaf wax hydrogen isotope fractionation relative to plant source water is best explained by membership in particular lineages, rather than by growth forms as previously suggested. Monocots, and in particular one clade of grasses, display consistently greater hydrogen isotopic fractionation than all other vascular plants, whereas lycopods, representing the earlier-diverging vascular plant lineage, display the smallest fractionation. Data from greenhouse experiments and field samples suggest that the changing leaf wax hydrogen isotopic fractionation in different terrestrial vascular plants may be related to different strategies in allocating photosynthetic substrates for metabolic and biosynthetic functions, and potential leaf water isotopic differences. PMID:25402476

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

PubMed Central

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

A comparative evaluation of the marginal adaptation of a thermoplastic resin, a light cured wax and an inlay casting wax on stone dies: An in vitro study.

PubMed

Gopalan, Reji P; Nair, Vivek V; Harshakumar, K; Ravichandran, R; Lylajam, S; Viswambaran, Prasanth

2018-01-01

Different pattern materials do not produce copings with satisfactory, marginal accuracy when used on stone dies at varying time intervals. The purpose of this study was to evaluate and compare the vertical marginal accuracy of patterns formed from three materials, namely, thermoplastic resin, light cured wax and inlay casting wax at three-time intervals of 1, 12, and 24 h. A master die (zirconia abutment mimicking a prepared permanent maxillary central incisor) and metal sleeve (direct metal laser sintering crown #11) were fabricated. A total of 30 stone dies were obtained from the master die. Ten patterns were made each from the three materials and stored off the die at room temperature. The vertical marginal gaps were measured using digital microscope at 1, 12, and 24 h after reseating with gentle finger pressure. The results revealed a significant statistical difference in the marginal adaptation of three materials at all the three-time intervals. Light cured wax was found to be most accurate at all time intervals, followed by thermoplastic resin and inlay casting wax. Furthermore, there was a significant difference between all pairs of materials. The change in vertical marginal gap from 1 to 24 h between thermoplastic resin and light cured wax was not statistically significant. The marginal adaptation of all the three materials used, was well within the acceptable range of 25-70 μm. The resin pattern materials studied revealed significantly less dimensional change than inlay casting wax on storage at 1, 12, and 24 h time intervals. They may be employed in situations where high precision and delayed investing is expected.

Three-dimensional wax patterning of paper fluidic devices.

PubMed

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

2014-06-17

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

Bacterial production of the biodegradable plastics polyhydroxyalkanoates.

PubMed

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

2014-09-01

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

The development of a method of producing etch resistant wax patterns on solar cells

NASA Technical Reports Server (NTRS)

Pastirik, E.

1980-01-01

A potentially attractive technique for wax masking of solar cells prior to etching processes was studied. This technique made use of a reuseable wax composition which was applied to the solar cell in patterned form by means of a letterpress printing method. After standard wet etching was performed, wax removal by means of hot water was investigated. Application of the letterpress wax printing process to silicon was met with a number of difficulties. The most serious shortcoming of the process was its inability to produce consistently well-defined printed patterns on the hard silicon cell surface.

OsWS1 involved in cuticular wax biosynthesis is regulated by osa-miR1848.

PubMed

Xia, Kuaifei; Ou, Xiaojin; Gao, Chunzhi; Tang, Huadan; Jia, Yongxia; Deng, Rufang; Xu, Xinlan; Zhang, Mingyong

2015-12-01

Cuticular wax forms a hydrophobic layer covering aerial plant organs and acting as a protective barrier against biotic and abiotic stresses. Compared with well-known wax biosynthetic pathway, molecular regulation of wax biosynthesis is less known. Here, we show that rice OsWS1, a member of the membrane-bound O-acyl transferase gene family, involved in wax biosynthesis and was regulated by an osa-miR1848. OsWS1-tagged green fluorescent protein localized to the endoplasmic reticulum (ER). Compared with wild-type rice, OsWS1 overexpression plants displayed a 3% increase in total wax, especially a 35% increase in very long-chain fatty acids, denser wax papillae around the stoma, more cuticular wax crystals formed on leaf and stem surfaces, pollen coats were thicker and more seedlings survived after water-deficit treatment. In contrast, OsWS1-RNAi and osa-miR1848 overexpression plants exhibited opposing changes. Gene expression analysis showed that overexpression of osa-miR1848 down-regulated OsWS1 transcripts; furthermore, expression profiles of OsWS1 and osa-miR1848 were inversely correlated in the leaf, panicle and stem, and upon water-deficit treatment. These results suggest that OsWS1 is regulated by osa-miR1848 and participates in cuticular wax formation. © 2015 John Wiley & Sons Ltd.

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

NASA Astrophysics Data System (ADS)

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

1999-11-01

Heterotrophic bacterial biomass, production, and respiration rates were measured during winter, spring, and summer in the subarctic NE Pacific from September 1995 to June 1997. Sampling took place on six cruises at five hydrographic stations along the east/west line-P transect from slope waters at P4 (1200 m depth) to the open-ocean waters at Ocean Station Papa (OSP) (4250 m depth). Interannual variability was small relative to seasonal and spatial variability. Biomass, derived from cell counts (assuming 20 fg C cell -1), was ca. 12 μg C l -1 in the winter and increased to 20-35 μg C l -1 in the spring and summer all along line-P. Bacterial production from [ 3H]-thymidine and [ 14C]-leucine incorporation rates was lowest in the winter (ca. 0.5 μg C l -1 d -1) with little spatial variability. Production increased 10-fold in spring at P4 (to ca. 4.5 μg C l -1 d -1). In contrast, only a 2-fold increase in bacterial production was observed over this period at the more oceanic stations. Rates of production in late summer were highest over the annual cycle at all stations ranging from ca. 6 at P4 to ca. 2 μg C l -1 d -1 at OSP. Bacterial (<1 μm size fraction) respiration, measured from dark-bottle O 2 consumption over 24 or 48 h, was <10 μg C l -1 d -1 during the winter and spring. Respiration rates increased >10-fold to ca. 100 μg C l -1 d -1 at P4 in the summer, but, interestingly, did not increase from spring to summer at the more oceanic stations. Thus bacterial growth efficiency, defined as production/(production+respiration), decreased in the spring westwards from the slope waters (P4) to the open-ocean (OSP), but increased westwards in the summer. Bacterial production was highly correlated with temperature at OSP ( r2=0.88) and less so at P4 ( r2=0.50). The observed temporal and spatial trends presented in this study suggest that seasonal changes in bacterial biomass were greatly affected by changes in loss processes, that bacterial biomass is regulated by

Optical Properties and Crystallization of Natural Waxes at Several Annealing Temperatures: a Terahertz Time-Domain Spectroscopy Study

NASA Astrophysics Data System (ADS)

Tian, Lu; Xu, Xinlong

2018-03-01

The thermal analysis and optical properties of paraffin wax, beeswax, and liquid paraffin annealed at variable temperatures have been conducted using terahertz time-domain spectroscopy (THz-TDS) coupled with SEM methods. The characteristic optical properties of natural waxes can be used to analyze natural wax adulteration. The lamellar structure of paraffin wax and beeswax grew by a sheet of chain expansion. Furthermore, the crystallization process of paraffin wax can be assigned: rotator-solid transition and liquid-solid ones. According to the temperature-dependent refractive index curves, the refractive index of paraffin wax varies from large to small followed by rotator-liquid transition, untreated one, and liquid-solid one, respectively. The results indicated that THz-TDS has been proved to be of great potential in identification the crystallization of waxes.

Hydrogen isotope fractionation in leaf waxes in the Alaskan Arctic tundra

NASA Astrophysics Data System (ADS)

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

Cuticular waxes in alpine meadow plants: climate effect inferred from latitude gradient in Qinghai-Tibetan Plateau.

PubMed

Guo, Yanjun; Guo, Na; He, Yuji; Gao, Jianhua

2015-09-01

Alpine meadow ecosystems are susceptible to climate changes. Still, climate impact on cuticular wax in alpine meadow plants is poorly understood. Assessing the variations of cuticular wax in alpine meadow plants across different latitudes might be useful for predicting how they may respond to climate change. We studied nine alpine meadows in a climate gradient in the east side of Qinghai-Tibetan Plateau, with mean annual temperature ranging from -7.7 to 3.2°C. In total, 42 plant species were analyzed for cuticular wax, averaged 16 plant species in each meadow. Only four plant species could be observed in all sampling meadows, including Kobresia humilis,Potentilla nivea,Anaphalis lacteal, and Leontopodium nanum. The amounts of wax compositions and total cuticular wax in the four plant species varied among sampling meadows, but no significant correlation could be observed between them and temperature, precipitation, and aridity index based on plant species level. To analyze the variations of cuticular wax on community level, we averaged the amounts of n-alkanes, aliphatic acids, primary alcohols, and total cuticular wax across all investigated plant species in each sampling site. The mean annual temperature, mean temperature in July, and aridity index were significantly correlated with the averaged amounts of wax compositions and total cuticular wax. The average chain length of n-alkanes in both plant and soil linearly increased with increased temperature, whereas reduced with increased aridity index. No significant correlation could be observed between mean annual precipitation and mean precipitation from June to August and the cuticular wax amounts and average chain length. Our results suggest that the survival of some alpine plants in specific environments might be depended on their abilities in adjusting wax deposition on plant leaves, and the alpine meadow plants as a whole respond to climate change, benefiting the stability of alpine meadow ecosystem.

Bacterial community changes in an industrial algae production system.

PubMed

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

2018-04-01

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

Methods of studying aging and stabilization of spray-congealed solid dispersions with carnauba wax. 1. Microcalorimetric investigation.

PubMed

Emås, M; Nyqvist, H

2000-03-20

Rapidly cooled materials are often unstable as a result of changes in their physical properties due to imperfect crystallization. In the process of spray-congealing, melted material is atomized into droplets which very quickly solidify. This increases the possibility of the material crystallizing in different metastable forms. In this study it is shown that isothermal microcalorimetry can be used to observe the change in the thermodynamic state of spray-congealed carnauba wax during storage. In order to accelerate the thermodynamic change in the spray-congealed wax, three annealing procedures have been developed and compared using isothermal microcalorimetry. By means of annealing, a spray-congealed product closer to a thermodynamically stable state has been achieved.

A core subunit of the RNA-processing/degrading exosome specifically influences cuticular wax biosynthesis in Arabidopsis.

PubMed

Hooker, Tanya S; Lam, Patricia; Zheng, Huanquan; Kunst, Ljerka

2007-03-01

The cuticle is an extracellular matrix composed of cutin polyester and waxes that covers aerial organs of land plants and protects them from environmental stresses. The Arabidopsis thaliana cer7 mutant exhibits reduced cuticular wax accumulation and contains considerably lower transcript levels of ECERIFERUM3/WAX2/YORE-YORE (CER3/WAX2/YRE), a key wax biosynthetic gene. We show here that CER7 protein is a putative 3'-5' exoribonuclease homologous to yeast Ribonuclease PH45 (RRP45p), a core subunit of the RNA processing and degrading exosome that controls the expression of CER3/WAX2/YRE. We propose that CER7 acts by degrading a specific mRNA species encoding a negative regulator of CER3/WAX2/YRE transcription. A second RRP45p homolog found in Arabidopsis, designated At RRP45a, is partially functionally redundant with CER7, and complete loss of RRP45 function in Arabidopsis is lethal. To our knowledge, CER7 is currently the only example of a core exosomal subunit specifically influencing a cellular process.

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

PubMed Central

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

Chemical composition of preen wax reflects major histocompatibility complex similarity in songbirds.

PubMed

Slade, J W G; Watson, M J; Kelly, T R; Gloor, G B; Bernards, M A; MacDougall-Shackleton, E A

2016-11-16

In jawed vertebrates, genes of the major histocompatibility complex (MHC) play a key role in immunity by encoding cell-surface proteins that recognize and bind non-self antigens. High variability at MHC suggests that these loci may also function in social signalling such as mate choice and kin recognition. This requires that MHC genotype covaries with some perceptible phenotypic trait. In mammals and fish, MHC is signalled chemically through volatile and non-volatile peptide odour cues, facilitating MHC-dependent mate choice and other behaviours. In birds, despite evidence for MHC-dependent mating, candidate mechanisms for MHC signalling remain largely unexplored. However, feather preen wax has recently been implicated as a potential source of odour cues. We examined whether the chemical composition of preen wax correlates with MHC class IIβ genotypes of wild song sparrows (Melospiza melodia). Pairwise chemical distance reflected amino acid distance at MHC for male-female dyads, although not for same-sex dyads. Chemical diversity did not reflect MHC diversity. We used gas chromatography-mass spectrometry (GC-MS) to characterize preen wax compounds, and identified four wax esters that best reflect MHC similarity. Provided songbirds can detect variation in preen wax composition, this cue may allow individuals to assess MHC compatibility of potential mates. © 2016 The Author(s).

Vacuum/compression valving (VCV) using parrafin-wax on a centrifugal microfluidic CD platform.

PubMed

Al-Faqheri, Wisam; Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Moebius, Jacob; Joseph, Karunan; Arof, Hamzah; Madou, Marc

2013-01-01

This paper introduces novel vacuum/compression valves (VCVs) utilizing paraffin wax. A VCV is implemented by sealing the venting channel/hole with wax plugs (for normally-closed valve), or to be sealed by wax (for normally-open valve), and is activated by localized heating on the CD surface. We demonstrate that the VCV provides the advantages of avoiding unnecessary heating of the sample/reagents in the diagnostic process, allowing for vacuum sealing of the CD, and clear separation of the paraffin wax from the sample/reagents in the microfluidic process. As a proof of concept, the microfluidic processes of liquid flow switching and liquid metering is demonstrated with the VCV. Results show that the VCV lowers the required spinning frequency to perform the microfluidic processes with high accuracy and ease of control.

Vacuum/Compression Valving (VCV) Using Parrafin-Wax on a Centrifugal Microfluidic CD Platform

PubMed Central

Al-Faqheri, Wisam; Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Moebius, Jacob; Joseph, Karunan; Arof, Hamzah; Madou, Marc

2013-01-01

This paper introduces novel vacuum/compression valves (VCVs) utilizing paraffin wax. A VCV is implemented by sealing the venting channel/hole with wax plugs (for normally-closed valve), or to be sealed by wax (for normally-open valve), and is activated by localized heating on the CD surface. We demonstrate that the VCV provides the advantages of avoiding unnecessary heating of the sample/reagents in the diagnostic process, allowing for vacuum sealing of the CD, and clear separation of the paraffin wax from the sample/reagents in the microfluidic process. As a proof of concept, the microfluidic processes of liquid flow switching and liquid metering is demonstrated with the VCV. Results show that the VCV lowers the required spinning frequency to perform the microfluidic processes with high accuracy and ease of control. PMID:23505528

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

PubMed

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 < .05) inhibited the 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 < .05) inhibitory effect on E. coli and E. faecalis, and at 12 hours also on P. mirabilis. For PHMB and thymol the results varied. At 6 hours, the ammonia concentration in the references (pH 6.0) was 200 to 300 ppm and it was 1500 to 1600 ppm at 8 hours. At pH 4.5, no or little ammonia production was measured at 6 and 8 hours. At pH 4.9, there was a significant reduction (P < .01). Chlorhexidine and PHMB exerted a significant (P < .01 or P < .001) inhibitory effect on ammonia production at both concentrations and at 6 and 8 hours. Thymol 0.003% and 0.03% showed inhibitory effect at both 6 hours (P < .01 or P < .001) and at 8 hours (P < .05 or P < .001). The method described in this study can be used to compare the ability of various disposable absorbent products to inhibit bacterial growth and ammonia

Physical characterization of crystalline networks formed by binary blends of waxes in soybean oil.

PubMed

Jana, Sarbojeet; Martini, Silvana

2016-11-01

The objective of this study is to analyze the physical properties of 2.5% (wt. basis) binary wax in soybean oil (SBO) system. Differential scanning calorimetry, pulsed nuclear magnetic resonance, rheology, and polarized light microscopy were used to measure melting profiles, solid fat content, viscoelastic parameters, and crystal morphology, respectively. Binary blends were prepared using beeswax (BW), rice bran wax (RBW), and sunflower wax (SFW) in 0, 20, 50, 80 and 100% proportions. Melting behavior of binary waxes was significantly affected by the type and proportion of wax used. Melting T on and T p for RBW/SFW and RBW/BW blends were significantly higher than those observed for SFW/BW. Enthalpy values suggest that different molecules present in the wax affect intermolecular interactions in the binary blends by either inducing (SFW/BW) or delaying (RBW/BW) crystallization. Iso-solid diagrams show that there is certainly a softening effect when different proportions of RBW/BW and SFW/BW are used, while a solid solution is formed in RBW/SFW systems. Viscoelastic parameters (G', G″) results show that RBW has the highest G' value (3.1×10 4 ±1×10 3 Pa) followed by SFW (2.7×10 4 ±0.2×10 4 Pa) and BW having the lowest (90.7±74.4Pa). Higher G' values in all proportions of RBW/SFW binary system in SBO indicate significantly more solid-like behavior than any other combinations. However, blending of two different waxes does not necessary result in a linear increase in elastic properties and in some cases no changes in elasticity is observed as the amount of the high melting wax is added to the low melting one. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

Chin-Leo, G; Kirchman, D L

1988-08-01

We examined the simultaneous incorporation of [H]thymidine and [C]leucine to obtain two independent indices of bacterial production (DNA and protein syntheses) in a single incubation. Incorporation rates of leucine estimated by the dual-label method were generally higher than those obtained by the single-label method, but the differences were small (dual/single = 1.1 +/- 0.2 [mean +/- standard deviation]) and were probably due to the presence of labeled leucyl-tRNA in the cold trichloroacetic acid-insoluble fraction. There were no significant differences in thymidine incorporation between dual- and single-label incubations (dual/ single = 1.03 +/- 0.13). Addition of the two substrates in relatively large amounts (25 nM) did not apparently increase bacterial activity during short incubations (<5 h). With the dual-label method we found that thymidine and leucine incorporation rates covaried over depth profiles of the Chesapeake Bay. Estimates of bacterial production based on thymidine and leucine differed by less than 25%. Although the need for appropriate conversion factors has not been eliminated, the dual-label approach can be used to examine the variation in bacterial production while ensuring that the observed variation in incorporation rates is due to real changes in bacterial production rather than changes in conversion factors or introduction of other artifacts.

Rapid Characterization of Bacterial Electrogenicity Using a Single-Sheet Paper-Based Electrofluidic Array

PubMed Central

Gao, Yang; Hassett, Daniel J.; Choi, Seokheun

2017-01-01

Electrogenicity, or bacterial electron transfer capacity, is an important application which offers environmentally sustainable advances in the fields of biofuels, wastewater treatment, bioremediation, desalination, and biosensing. Significant boosts in this technology can be achieved with the growth of synthetic biology that manipulates microbial electron transfer pathways, thereby potentially significantly improving their electrogenic potential. There is currently a need for a high-throughput, rapid, and highly sensitive test array to evaluate the electrogenic properties of newly discovered and/or genetically engineered bacterial species. In this work, we report a single-sheet, paper-based electrofluidic (incorporating both electronic and fluidic structure) screening platform for rapid, sensitive, and potentially high-throughput characterization of bacterial electrogenicity. This novel screening array uses (i) a commercially available wax printer for hydrophobic wax patterning on a single sheet of paper and (ii) water-dispersed electrically conducting polymer mixture, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, for full integration of electronic and fluidic components into the paper substrate. The engineered 3-D, microporous, hydrophilic, and conductive paper structure provides a large surface area for efficient electron transfer. This results in rapid and sensitive power assessment of electrogenic bacteria from a microliter sample volume. We validated the effectiveness of the sensor array using hypothesis-driven genetically modified Pseudomonas aeruginosa mutant strains. Within 20 min, we observed that the sensor platform successfully measured the electricity-generating capacities of five isogenic mutants of P. aeruginosa while distinguishing their differences from genetically unmodified bacteria. PMID:28798914

Bacterial symbionts and natural products.

PubMed

Crawford, Jason M; Clardy, Jon

2011-07-21

The study of bacterial symbionts of eukaryotic hosts has become a powerful discovery engine for chemistry. This highlight looks at four case studies that exemplify the range of chemistry and biology involved in these symbioses: a bacterial symbiont of a fungus and a marine invertebrate that produce compounds with significant anticancer activity, and bacterial symbionts of insects and nematodes that produce compounds that regulate multilateral symbioses.

Bacterial and fungal composition profiling of microbial based cleaning products.

PubMed

Subasinghe, R M; Samarajeewa, A D; Meier, M; Coleman, G; Clouthier, H; Crosthwait, J; Tayabali, A F; Scroggins, R; Shwed, P S; Beaudette, L A

2018-06-01

Microbial based cleaning products (MBCPs) are a new generation of cleaning products that are gaining greater use in household, institutional, and industrial settings. Little is known about the exact microbial composition of these products because they are not identified in detail on product labels and formulations are often proprietary. To gain a better understanding of their microbial and fungal composition towards risk assessment, the cultivable microorganisms and rDNA was surveyed for microbial content in five different MBCPs manufactured and sold in North America. Individual bacterial and fungal colonies were identified by ribosequencing and fatty acid methyl ester (FAME) gas chromatography. Metagenomic DNA (mDNA) corresponding to each of the products was subjected to amplification and short read sequencing of seven of the variable regions of the bacterial 16S ribosomal DNA. Taken together, the cultivable microorganism and rDNA survey analyses showed that three of the products were simple mixtures of Bacillus species. The two other products featured a mixture of cultivable fungi with Bacilli, and by rDNA survey analysis, they featured greater microbial complexity. This study improves our understanding of the microbial composition of several MBCPs towards a more comprehensive risk assessment. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Wax removal for accelerated cotton scouring with alkaline pectinase.

PubMed

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.

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

PubMed

Servais, P

1995-03-01

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

Chemical Composition and Crystal Morphology of Epicuticular Wax in Mature Fruits of 35 Pear (Pyrus spp.) Cultivars

PubMed Central

Wu, Xiao; Yin, Hao; Shi, Zebin; Chen, Yangyang; Qi, Kaijie; Qiao, Xin; Wang, Guoming; Cao, Peng; Zhang, Shaoling

2018-01-01

An evaluation of fruit wax components will provide us with valuable information for pear breeding and enhancing fruit quality. Here, we dissected the epicuticular wax concentration, composition and structure of mature fruits from 35 pear cultivars belonging to five different species and hybrid interspecies. A total of 146 epicuticular wax compounds were detected, and the wax composition and concentration varied dramatically among species, with the highest level of 1.53 mg/cm2 in Pyrus communis and the lowest level of 0.62 mg/cm2 in Pyrus pyrifolia. Field emission scanning electron microscopy (FESEM) analysis showed amorphous structures of the epicuticular wax crystals of different pear cultivars. Cluster analysis revealed that the Pyrus bretschneideri cultivars were grouped much closer to Pyrus pyrifolia and Pyrus ussuriensis, and the Pyrus sinkiangensis cultivars were clustered into a distant group. Based on the principal component analysis (PCA), the cultivars could be divided into three groups and five groups according to seven main classes of epicuticular wax compounds and 146 wax compounds, respectively. PMID:29875784

Effect of spatial distribution of wax and PEG-isocyanate on the morphology and hydrophobicity of starch films.

PubMed

Muscat, Delina; Adhikari, Raju; Tobin, Mark J; McKnight, Stafford; Wakeling, Lara; Adhikari, Benu

2014-10-13

This study proposes a novel method for improving surface hydrophobicity of glycerol plasticized high amylose (HAG) films. We used polyethylene glycol isocyanate (PEG-iso) crosslinker to link HAG and three natural waxes (beeswax, candelilla wax and carnauba wax) to produce HAG+wax+PEG-iso films. The spatial distributions of wax and PEG-iso across the thickness of these films were determined using Synchrotron-based Fourier transform infrared spectroscopy. The hydrophobicity and surface morphology of the films were determined using contact angle (CA) and scanning electron microscopic measurements, respectively. The distribution patterns of wax and the PEG-iso across the thickness of the film, and the nature of crystalline patterns formed on the surface of these films were found to be the key factors affecting surface hydrophobicity. The highest hydrophobicity (CA >90°) was created when the PEG-iso was primarily distributed in the interior of the films and a hierarchical circular pinnacle structure of solidified wax was formed on the surface. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed Central

Chin-Leo, Gerardo; Kirchman, David L.

1988-01-01

We examined the simultaneous incorporation of [3H]thymidine and [14C]leucine to obtain two independent indices of bacterial production (DNA and protein syntheses) in a single incubation. Incorporation rates of leucine estimated by the dual-label method were generally higher than those obtained by the single-label method, but the differences were small (dual/single = 1.1 ± 0.2 [mean ± standard deviation]) and were probably due to the presence of labeled leucyl-tRNA in the cold trichloroacetic acid-insoluble fraction. There were no significant differences in thymidine incorporation between dual- and single-label incubations (dual/ single = 1.03 ± 0.13). Addition of the two substrates in relatively large amounts (25 nM) did not apparently increase bacterial activity during short incubations (<5 h). With the dual-label method we found that thymidine and leucine incorporation rates covaried over depth profiles of the Chesapeake Bay. Estimates of bacterial production based on thymidine and leucine differed by less than 25%. Although the need for appropriate conversion factors has not been eliminated, the dual-label approach can be used to examine the variation in bacterial production while ensuring that the observed variation in incorporation rates is due to real changes in bacterial production rather than changes in conversion factors or introduction of other artifacts. PMID:16347706

Major constituents of the foliar epicuticular waxes of species from the Caatinga and Cerrado.

PubMed

Oliveira, A F; Salatino, A

2000-01-01

The epicuticular waxes of leaves of four species (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro) from the Caatinga, (a semi-arid ecosystem of Northeast Brazil) and four species (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa) from the Cerrado, (a savanna ecosystem covering one third of the Brazilian territory), were analyzed. Six species contained a high content (above 60 microg x cm(-2)) of wax, four of them from the Caatinga. Triterpenoids and n-alkanes were the most frequent and abundant constituents found in the species from both habitats. The distribution of n-alkanes predominated by homologues with 27, 29, 31 and 33 carbon atoms, displayed no consistent differences between species from the two habitats. Lupeol, beta-amyrin, epifriedelinol and ursolic acid were the triterpenoids found. Triterpenoids clearly predominate over alkanes in the waxes from the Cerrado species. The waxes of two evergreen species from the Caatinga yielded n-alkanes as predominant constituents. A comparison of foliar epicuticular waxes of native plants from ecosystems with different hydric constraints is discussed.

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

PubMed

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

2007-10-01

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

21 CFR 186.1555 - Japan wax.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ingredient is used as a constituent of cotton and cotton fabrics used for dry food packaging. (2) The... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Japan wax. 186.1555 Section 186.1555 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD...

21 CFR 172.886 - Petroleum wax.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

Formulation of wax oxybenzone microparticles using a factorial approach.

PubMed

Gomaa, Y A; Darwish, I A; Boraei, N A; El-Khordagui, L K

2010-01-01

Oxybenzone wax microparticles (MPs) were prepared by the hydrophobic congealable disperse phase method. The formulation of oxybenzone-loaded MPs was optimized using a 2⁴ experimental design. Factorial analysis indicated that the main MP characteristics were influenced by initial drug loading, emulsification speed, emulsifier concentration and hydrophilic-lipophilic balance. MPs were spherical with 50.5–88.1 μm size range, 17.8–38.9 drug content in mg/100 mg MPs and 33.1–87.2% oxybenzone release in 1 h. A wide range of sunscreen delivery systems suitable for different formulation purposes were generated which may contribute to the advanced formulation of sunscreen products with improved performance.

Viral lysis, flagellate grazing potential, and bacterial production in Lake Pavin.

PubMed

Bettarel, Y; Amblard, C; Sime-Ngando, T; Carrias, J-F; Sargos, D; Garabétian, F; Lavandier, P

2003-02-01

Abundances of different compartments of the microbial loop (i.e., viruses, heterotrophic bacteria, nonpigmented nanoflagellates, and pigmented nanoflagellates), bacterial heterotrophic production (BHP), viral lysis, and potential flagellate grazing impacts on the bacterial assemblages were estimated during a short-term study (24 h) conducted in June 1998 in the epilimnion (5 m) and metalimnion (10 m) of a moderate-altitude oligomesotrophic lake (Lake Pavin, France). Viral and bacterial abundances were higher in the metalimnion than in the epilimnion, whereas pigmented and nonpigmented nanoflagellates were more numerous in the epilimnion. The control of the BHP due to viral lysis (determined by examination of viral-containing bacteria using a transmission electron microscope) was significantly higher in the meta- (range = 6.0-33.7%, mean = 15.6%) than in the epilimnion (3.5-10.3%, 6.4%). The same was for the losses of BHP from the potential predation by nanoflagellates which ranged from 0.5 to 115.4% (mean = 38.7%) in the epilimnion, and from 0.7 to 97.5% (mean = 66.7%) in the metalimnion. Finally, estimated viral mediated mortality rates from the percentage of visibly infected cells and potential nanoflagellate grazing rates based on assumed clearance rates suggest that flagellates consumed a larger proportion of bacterial production than was lost to viral lysis.

Comparable hydrogen isotopic fractionation of plant leaf wax n-alkanoic acids in arid and humid subtropical ecosystems

NASA Astrophysics Data System (ADS)

Gao, Li; Zheng, Mei; Fraser, Matthew; Huang, Yongsong

2014-02-01

Leaf wax hydrogen isotope proxies have been widely used to reconstruct past hydrological changes. However, published reconstructions have given little consideration for the potentially variable hydrogen isotopic fractionation relative to precipitation (ɛwax-p) under different climate and environmental settings. Chief among various potential factors controlling fractionation is relative humidity, which is known to strongly affect oxygen isotopic ratios of plant cellulose, but its effect on hydrogen isotopic fractionation of leaf waxes is still ambiguous. Analyses of lake surface sediments and individual modern plants have provided valuable information on the variability of ɛwax-p, but both approaches have significant limitations. Here, we present an alternative method to obtain the integrated, time-resolved ecosystem-level ɛwax-p values, by analyzing modern aerosol samples collected weekly from arid (Arizona lowlands) and humid subtropical (Atlanta, Georgia) environments during the main growth season. Because aerosol samples mainly reflect regional leaf wax resources, the extreme contrast in the hydroclimate and associated vegetation assemblages between our study sites allows us to rigorously assess the impact of relative humidity and associated vegetation assemblages on leaf wax hydrogen isotopic fractionation. We show there is only minor difference (mostly <10‰) in the mean ɛwax-p values in the two end-member environments. One possible explanation is that the positive isotopic effects of low relative humidity are offset by progressive replacement of trees with grasses that have a more negative apparent fractionation. Our results represent an important step toward quantitative interpretation of leaf wax hydrogen isotopic records.

Temperature-enhanced alumina HPLC method for the analysis of wax esters, sterol esters, and methyl esters.

PubMed

Moreau, Robert A; Kohout, Karen; Singh, Vijay

2002-12-01

Previous attempts at separating nonpolar lipid esters (including wax esters, sterol esters, and methyl esters) have achieved only limited success. Among the several normal-phase methods tested, a single recent report of a method employing an alumina column at 30 degrees C with a binary gradient system was the most promising. In the current study, modification of the alumina method by increasing the column temperature to 75 degrees C improved the separation of standards of wax esters and sterol esters. Elevated column temperature also enhanced the separation of FAME with differing degrees of unsaturation. Evidence was also presented to indicate that the method similarly separated phytosterol esters, based on their levels of unsaturation. With the increased interest in phytosterol- and phytostanol-ester enriched functional foods, this method should provide a technique to characterize and compare these products.

Hydrogen isotope composition of leaf wax n-alkanes in glaucous and non-glaucous varieties of wheat (Triticum spp.)

NASA Astrophysics Data System (ADS)

Pedentchouk, Nikolai; Eley, Yvette; Frizell-Armitage, Amelia; Uauy, Cristobal

2015-04-01

The use of the 2H/1H composition of terrestrial plants in climate and ecology studies depends on fundamental understanding of the processes within the plant that control fractionation of these two isotopes. Little is currently known about the extent of 2H/1H fractionation at different steps of biosynthesis, after the initial H uptake following leaf water photolysis. Knowing this effect is particularly important when seeking to interpret the 2H/1H composition of leaf wax biomarkers from plants that differ in the amount and type of individual compound classes in their leaf waxes. The purpose of this study was to investigate the link between the quantity and distribution of n-alkyl lipids in leaf waxes and their isotopic composition. We used a genetic approach to suppress glaucousness in 2 varieties of wheat (Alchemy and Malacca), which resulted in glaucous and non-glaucous phenotypes of both varieties. Both phenotypes were then grown outdoors under identical environmental conditions in central Norfolk, UK. At the end of the growing season, the plants were sampled for soil water, leaf water, and leaf wax isotopic measurements. Comparison of the leaf wax composition of the non-glaucous and glaucous phenotypes revealed that the non-glaucous varieties were characterised by the absence of diketones and a greater concentration of n-alkanes and primary alcohols.. Our results showed very small differences between glaucous and non-glaucous varieties with regard to soil (mean values, <2 per mil) and leaf (<1 per mil) water 2H/1H. Conversely, there was 15-20 and 10-15 per mil 2H-depletion in the C29 and C31 n-alkanes, respectively, from the non-glaucous phenotype. This 2H-depletion in the non-glaucous phenotype demonstrated that the suppression of diketone production and the increase in n-alkane and primary alcohol concentrations are linked with a shift in the 2H/1H composition of n-alkanes. The initial results of this work suggest that plants using the same environmental water

Combined hydrogen and carbon isotopes of plant waxes as an indicator of drought impacts on ancient Maya agriculture

NASA Astrophysics Data System (ADS)

Douglas, P. M.; Pagani, M.; Eglinton, T. I.; Brenner, M.; Hodell, D. A.; Curtis, J. H.

2012-12-01

There is increasing evidence suggesting that a series of droughts in the Yucatan Peninsula coincided with the Terminal Classic decline of the Classic Maya civilization (ca. 1250 to 1000 years BP). However, there is little evidence directly linking climatic change and changes in human activities in this region. In this study we combine plant-wax δD, δ13C, and Δ14C analyses in two lake sediment cores from southeastern Mexico and northern Guatemala to develop coupled records of hydroclimate variability and human-driven vegetation change. Plant-wax specific Δ14C ages indicate a large input of pre-aged plant waxes into lake sediment. Comparison of plant-wax δD records with other regional hydroclimate proxy records suggest that plant-wax ages are evenly distributed around plant-wax radiocarbon ages, and that applying an age model based on plant-wax radiocarbon ages is appropriate for these lake sediments. We evaluate how differences in plant-wax age distributions influence stable isotope records to assess the age uncertainty associated with records of climate and vegetation change derived from plant-wax stable isotopes. In this low-elevation tropical environment plant-wax δ13C is largely controlled by the relative abundance of C3 and C4 plants. The ancient Maya practiced widespread maize (C4) agriculture and strongly influenced regional C3-C4 vegetation dynamics. Under natural conditions C4 plant coverage and plant-wax δ13C would tend to co-vary positively since C4 plants are well adapted for dry conditions. Under ancient Maya land-use, however, this relationship is likely to be decoupled, since drought would have disrupted C4 agriculture. Combined analysis of plant-wax δD and δ13C from both lakes indicates increasingly divergent trends following ca. 3500 years BP, around the onset of widespread ancient Maya agriculture. After this time high plant-wax δD values tend to correspond with low plant-wax δ13C values and vice versa. This pattern is consistent with

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

PubMed

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.

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

PubMed

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.

Production of Phloroglucinol, a Platform Chemical, in Arabidopsis using a Bacterial Gene.

PubMed

Abdel-Ghany, Salah E; Day, Irene; Heuberger, Adam L; Broeckling, Corey D; Reddy, Anireddy S N

2016-12-07

Phloroglucinol (1,3,5-trihydroxybenzene; PG) and its derivatives are phenolic compounds that are used for various industrial applications. Current methods to synthesize PG are not sustainable due to the requirement for carbon-based precursors and co-production of toxic byproducts. Here, we describe a more sustainable production of PG using plants expressing a native bacterial or a codon-optimized synthetic PhlD targeted to either the cytosol or chloroplasts. Transgenic lines were analyzed for the production of PG using gas and liquid chromatography coupled to mass spectroscopy. Phloroglucinol was produced in all transgenic lines and the line with the highest PhlD transcript level showed the most accumulation of PG. Over 80% of the produced PG was glycosylated to phlorin. Arabidopsis leaves have the machinery to glycosylate PG to form phlorin, which can be hydrolyzed enzymatically to produce PG. Furthermore, the metabolic profile of plants with PhlD in either the cytosol or chloroplasts was altered. Our results provide evidence that plants can be engineered to produce PG using a bacterial gene. Phytoproduction of PG using a bacterial gene paves the way for further genetic manipulations to enhance the level of PG with implications for the commercial production of this important platform chemical in plants.

Development and properties of a wax ester hydrolase in the cotyledons of jojoba seedlings.

PubMed

Huang, A H; Moreau, R A; Liu, K D

1978-03-01

The activity of a wax ester hydrolase in the cotyledons of jojoba (Simmondsia chinensis) seedlings increased drastically during germination, parallel to the development of the gluconeogenic process. The enzyme at its peak of development was obtained in association with the wax body membrane, and its properties were studied. It had an optimal activity at alkaline pH (8.5-9). The apparent K(m) value for N-methylindoxylmyristate was 93 muM. It was stable at 40 C for 30 min but was inactivated at higher temperature. Various divalent cations and ethylenediaminetetraacetate had little effect on the activity. p-Chloromercuribenzoate was a strong inhibitor of the enzyme activity, and its effect was reversed by subsequent addition of dithiothreitol. It had a broad substrate specificity with highest activities on monoglycerides, wax esters, and the native substrate (jojoba wax).

76 FR 773 - Petroleum Wax Candles From the People's Republic of China: Continuation of Antidumping Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-06

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-504] Petroleum Wax Candles From... Trade Commission (``ITC'') that revocation of the antidumping duty order on petroleum wax candles from... order on petroleum wax candles from the PRC pursuant to section 751(c)(2) of the Tariff Act of 1930, as...

The in situ bacterial production of fluorescent organic matter; an investigation at a species level.

PubMed

Fox, B G; Thorn, R M S; Anesio, A M; Reynolds, D M

2017-11-15

Aquatic dissolved organic matter (DOM) plays an essential role in biogeochemical cycling and transport of organic matter throughout the hydrological continuum. To characterise microbially-derived organic matter (OM) from common environmental microorganisms (Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa), excitation-emission matrix (EEM) fluorescence spectroscopy was employed. This work shows that bacterial organisms can produce fluorescent organic matter (FOM) in situ and, furthermore, that the production of FOM differs at a bacterial species level. This production can be attributed to structural biological compounds, specific functional proteins (e.g. pyoverdine production by P. aeruginosa), and/or metabolic by-products. Bacterial growth curve data demonstrates that the production of FOM is fundamentally related to microbial metabolism. For example, the majority of Peak T fluorescence (> 75%) is shown to be intracellular in origin, as a result of the building of proteins for growth and metabolism. This underpins the use of Peak T as a measure of microbial activity, as opposed to bacterial enumeration as has been previously suggested. This study shows that different bacterial species produce a range of FOM that has historically been attributed to high molecular weight allochthonous material or the degradation of terrestrial FOM. We provide definitive evidence that, in fact, it can be produced by microbes within a model system (autochthonous), providing new insights into the possible origin of allochthonous and autochthonous organic material present in aquatic systems. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Development of lamellar structures in natural waxes - an electron diffraction investigation

NASA Astrophysics Data System (ADS)

Dorset, Douglas L.

1999-06-01

When they are recrystallized from the melt, natural plant or insect waxes tend to form solid phases with a nematic-like structure (i.e. a parallel array of polymethylene chains with little or no aggregation of the molecules into distinct layers). An electron diffraction study of carnauba wax and two types of beeswax has shown that the degree of molecular organization into lamellar structures can be enhanced by annealing in the presence of benzoic acid, which also acts as an epitaxial substrate. Nevertheless, the resultant layer structure in the annealed solid is not the same as that found for paraffin wax fractions refined from petroleum. Probably because of a small but significant fraction of a very long chain ingredient, the lamellar separation is incomplete, incorporating a number of `bridging molecules' that span the nascent lamellar interface.The same phenomenon has been described recently for a low molecular weight polyethylene.

MIXTA-Like Transcription Factors and WAX INDUCER1/SHINE1 Coordinately Regulate Cuticle Development in Arabidopsis and Torenia fournieri[C][W

PubMed Central

Oshima, Yoshimi; Shikata, Masahito; Koyama, Tomotsugu; Ohtsubo, Norihiro; Mitsuda, Nobutaka; Ohme-Takagi, Masaru

2013-01-01

The waxy plant cuticle protects cells from dehydration, repels pathogen attack, and prevents organ fusion during development. The transcription factor WAX INDUCER1/SHINE1 (WIN1/SHN1) regulates the biosynthesis of waxy substances in Arabidopsis thaliana. Here, we show that the MIXTA-like MYB transcription factors MYB106 and MYB16, which regulate epidermal cell morphology, also regulate cuticle development coordinately with WIN1/SHN1 in Arabidopsis and Torenia fournieri. Expression of a MYB106 chimeric repressor fusion (35S:MYB106-SRDX) and knockout/down of MYB106 and MYB16 induced cuticle deficiencies characterized by organ adhesion and reduction of epicuticular wax crystals and cutin nanoridges. A similar organ fusion phenotype was produced by expression of a WIN1/SHN1 chimeric repressor. Conversely, the dominant active form of MYB106 (35S:MYB106-VP16) induced ectopic production of cutin nanoridges and increased expression of WIN1/SHN1 and wax biosynthetic genes. Microarray experiments revealed that MYB106 and WIN1/SHN1 regulate similar sets of genes, predominantly those involved in wax and cutin biosynthesis. Furthermore, WIN1/SHN1 expression was induced by MYB106-VP16 and repressed by MYB106-SRDX. These results indicate that the regulatory cascade of MIXTA-like proteins and WIN1/SHN1 coordinately regulate cutin biosynthesis and wax accumulation. This study reveals an additional key aspect of MIXTA-like protein function and suggests a unique relationship between cuticle development and epidermal cell differentiation. PMID:23709630

Impact of changing wax type during storage on mandarin flavor and quality attributes

USDA-ARS?s Scientific Manuscript database

Mandarin (Citrus reticulata Blanco) packers sometimes apply a storage wax (SW) designed to limit water loss during the initial part of storage and then replace it with a higher shine pack wax (PW) prior to shipment of the fruit. Mandarins are prone to the development of off-flavors as a result of lo...

Compound-Specific Radiocarbon Dating Reveals the Age Distribution of Plant-Wax Biomarkers Exported to the Bengal Fan

NASA Astrophysics Data System (ADS)

Galy, V.; French, K. L.; Hein, C. J.; Haghipour, N.; Wacker, L.; Kudrass, H.; Eglinton, T. I.

2017-12-01

The stable isotope composition of leaf-wax compounds preserved in lacustrine and marine sediments has been widely used to reconstruct terrestrial paleo-environments. However, the timescales of plant-wax storage in continental reservoirs before riverine export are not well known, representing a key uncertainty in paleo-environment studies. We couple numerical models with bulk and leaf-wax fatty acid organic 13C and 14C signatures hosted in a high-deposition-rate sediment core from the Bengal shelf canyon in order to estimate storage timescales within the Ganges-Brahmaputra catchment area. The fatty acid 14C record reveals a muted nuclear weapons bomb spike, requiring that the Ganges-Brahmaputra river system exports a mixture of young and old (pre-aged) leaf-wax compounds. According to numerical simulations, 79-83% of the leaf-wax fatty acids in this core are sourced from continental reservoirs that store organic carbon on an average of 1000-1200 calendar years, while the remainder has an average age of 15 years. These results demonstrate that a majority of the leaf-wax compounds produced in the Ganges-Brahmaputra river basin was stored in soils, floodplains, and wetlands prior to its export to the Bengal Fan. We will discuss the implications of these findings for plant-wax based paleoenvironmental records.

Isotopomers as a method for differentiating between bacterial and fungal production of nitrous oxide

NASA Astrophysics Data System (ADS)

Sutka, R. L.; Adams, G.; Ostrom, N.; Ostrom, P.

2007-12-01

In order to study the importance of fungi to nitrous oxide (N2O) production in the environment it is critical to have a non-intrusive method for differentiating between fungal and bacterial N2O production. Site preference (SP), the difference in d15N between the central and outer N atoms in N2O, has been used to differentiate between bacterial nitrification and denitrification. In this study we compare the SP, d15N and d18O of N2O produced by the two best-studied fungal denitrifiers, Fusarium oxysporum and Cylindrocarpon tonkinense, to data from our previous bacterial studies. Both d18O and SP values remained fairly constant during the course of nitrite reduction which likely reflects isotopic exchange with water in the case of d18O and conservative behavior in SP that has been observed previously (Sutka et al., 2006). We observed a wide range of fractionation factors for fungal denitrification, -74.7 to -6.6 ‰, and non-linear behavior indicating that fractionation was controlled by more than one step. We interpret the small degree of fractionation as reflecting fractionation during diffusion and the more negative values as being controlled by enzymatic fractionation. Data from this and our previous study of bacterial production (Sutka et al., 2006) reveals that N2O produced via nitrification by fungi can be differentiated from N2O produced by bacterial denitrification primarily on the basis of d18O. The site preference of N2O produced by F. oxysporum and C. tonkinense was 37.1 ± 2.5 ‰ and 36.9 ± 2.8 ‰, respectively. These results indicate that isotopomers can be used as a basis for differentiating bacterial and fungal denitrification. Our work further reveals the role that fungal and bacterial nitric oxide reductases have in determining site preference during N2O production.

Temperature controls on aquatic bacterial production and community dynamics in arctic lakes and streams.

PubMed

Adams, Heather E; Crump, Byron C; Kling, George W

2010-05-01

The impact of temperature on bacterial activity and community composition was investigated in arctic lakes and streams in northern Alaska. Aquatic bacterial communities incubated at different temperatures had different rates of production, as measured by (14)C-leucine uptake, indicating that populations within the communities had different temperature optima. Samples from Toolik Lake inlet and outlet were collected at water temperatures of 14.2 degrees C and 15.9 degrees C, respectively, and subsamples incubated at temperatures ranging from 6 degrees C to 20 degrees C. After 5 days, productivity rates varied from 0.5 to approximately 13.7 microg C l(-1) day(-1) and two distinct activity optima appeared at 12 degrees C and 20 degrees C. At these optima, activity was 2- to 11-fold higher than at other incubation temperatures. The presence of two temperature optima indicates psychrophilic and psychrotolerant bacteria dominate under different conditions. Community fingerprinting via denaturant gradient gel electrophoresis (DGGE) of 16S rRNA genes showed strong shifts in the composition of communities driven more by temperature than by differences in dissolved organic matter source; e.g. four and seven unique operational taxonomic units (OTUs) were found only at 2 degrees C and 25 degrees C, respectively, and not found at other incubation temperatures after 5 days. The impact of temperature on bacteria is complex, influencing both bacterial productivity and community composition. Path analysis of measurements of 24 streams and lakes sampled across a catchment 12 times in 4 years indicates variable timing and strength of correlation between temperature and bacterial production, possibly due to bacterial community differences between sites. As indicated by both field and laboratory experiments, shifts in dominant community members can occur on ecologically relevant time scales (days), and have important implications for understanding the relationship of bacterial

Geometrical effects of conventional and digital prosthodontic planning wax-ups on lateral occlusal contact number, contact area, and steepness.

PubMed

Abduo, Jaafar

2017-01-01

This study evaluated and compared the effect of conventional and digital wax-ups on three lateral occlusion variables: contact number, contact area, and steepness. Dental casts of 10 patients with Angle Class I relationship were included in the study. All patients required fixed prosthodontic treatment that would affect lateral occlusion. The casts of all patients received conventional and digital wax-ups. For pretreatment, conventional wax-up, and digital wax-up casts, contact number, contact area, and occlusion steepness were measured at four lateral positions, that is, at excursions of 0.5, 1.0, 2.0, and 3.0 mm from maximal intercuspation. Lateral occlusion scheme variables were affected by use of diagnostic wax-ups. For all types of casts, contact number decreased as excursion increased. The two types of wax-ups had similar contact number patterns, and contact number was significantly greater for these casts than for pretreatment casts in the earlier stages of excursion. Similarly, contact area gradually decreased with increasing excursion in the pretreatment and conventional and digital wax-up casts. There was only a minimal decrease in occlusion steepness as excursion increased. However, lateral occlusion was generally steeper for digital wax-up casts.

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

PubMed

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.

Th2 Allergic Immune Response to Inhaled Fungal Antigens is Modulated By TLR-4-Independent Bacterial Products

PubMed Central

Allard, Jenna B.; Rinaldi, Lisa; Wargo, Matt; Allen, Gilman; Akira, Shizuo; Uematsu, Satoshi; Poynter, Matthew E.; Hogan, Deborah A.; Rincon, Mercedes; Whittaker, Laurie A.

2009-01-01

SUMMARY Allergic airway disease is characterized by eosinophilic inflammation, mucus hypersecretion and increased airway resistance. Fungal antigens are ubiquitous within the environment and are well know triggers of allergic disease. Bacterial products are also frequently encountered within the environment and may alter the immune response to certain antigens. The consequence of simultaneous exposure to bacterial and fungal products on the lung adaptive immune response has not been explored. Here we show that oropharyngeal aspiration of fungal lysates (Candida albicans, Aspergillus fumigatus) promotes airway eosinophilia, secretion of Th2 cytokines and mucus cell metaplasia. In contrast, oropharyngeal exposure to bacterial lysates (Pseudomonas aeruginosa) promotes airway inflammation characterized by neutrophils, Th1 cytokine secretion and no mucus production. More importantly, administration of bacterial lysates together with fungal lysates deviates the adaptive immune response to a Th1 type associated with neutrophilia and diminished mucus production. The immunomodulatory effect that bacterial lysates have on the response to fungi is TLR4-independent but MyD88 dependent. Thus, different types of microbial products within the airway can alter the host's adaptive immune response, and potentially impact the development of allergic airway disease to environmental fungal antigens. PMID:19224641

A review of the performance and structural considerations of paraffin wax hybrid rocket fuels with additives

NASA Astrophysics Data System (ADS)

Veale, Kirsty; Adali, Sarp; Pitot, Jean; Brooks, Michael

2017-12-01

Paraffin wax as a hybrid rocket fuel has not been comprehensively characterised, especially regarding the structural feasibility of the material in launch applications. Preliminary structural testing has shown paraffin wax to be a brittle, low strength material, and at risk of failure under launch loading conditions. Structural enhancing additives have been identified, but their effect on motor performance has not always been considered, nor has any standard method of testing been identified between research institutes. A review of existing regression rate measurement techniques on paraffin wax based fuels and the results obtained with various additives are collated and discussed in this paper. The review includes 2D slab motors that enable visualisation of liquefying fuel droplet entrainment and the effect of an increased viscosity on the droplet entrainment mechanism, which can occur with the addition of structural enhancing polymers. An increased viscosity has been shown to reduce the regression rate of liquefying fuels. Viscosity increasing additives that have been tested include EVA and LDPE. Both these additives increase the structural properties of paraffin wax, where the elongation and UTS are improved. Other additives, such as metal hydrides, aluminium and boron generally offer improvements on the regression rate. However, very little consideration has been given to the structural effects these additives have on the wax grain. A 40% aluminised grain, for example, offers a slight increase in the UTS but reduces the elongation of paraffin wax. Geometrically accurate lab-scale motors have also been used to determine the regression rate properties of various additives in paraffin wax. A concise review of all available regression rate testing techniques and results on paraffin wax based hybrid propellants, as well as existing structural testing data, is presented in this paper.

Wax-tear and meibum protein, wax–β-carotene interactions in vitro using infrared spectroscopy

PubMed Central

Faheem, Samad; Kim, Sung-Hye; Nguyen, Jonathan; Neravetla, Shantanu; Ball, Matthew; Foulks, Gary N; Yappert, Marta C; Borchman, Douglas

2012-01-01

Protein–meibum and terpenoids–meibum lipid interactions could be important in the etiology of meibomian gland dysfunction (MGD) and dry eye symptoms. In the current model studies, attenuated total reflectance (ATR) infrared (IR) spectroscopy was used to determine if the terpenoid β-carotene and the major proteins in tears and meibum affect the hydrocarbon chain conformation and carbonyl environment of wax, an abundant component of meibum. The main finding of these studies is that mucin binding to wax disordered slightly the conformation of the hydrocarbon chains of wax and caused the wax carbonyls to become hydrogen bonded or experience a more hydrophilic environment. Lysozyme and lactoglobulin, two proteins shown to bind to monolayers of meibum, did not have such an effect. Keratin and β-carotene did not affect the fluidity (viscosity) or environment of the carbonyl moieties of wax. Based on these results, tetraterpenoids are not likely to influence the structure of meibum in the meibomian glands. In addition, these findings suggest that it is unlikely that keratin blocks meibomian glands by causing the meibum to become more viscous. Among the tear fluid proteins studied, mucin is the most likely to influence the conformation and carbonyl environment of meibum at the tear film surface. PMID:22564968

Sustaining pattern of phenformin hydrochloride using various polymers and waxes.

PubMed

Pandey, V P; Kannappan, N; Manavalan, R; Subburaj, T

2002-01-01

The present study was carried out to formulate matrix tablets of phenformin hydrochloride. Granules of phenformin HCl were prepared by using ethyl cellulose, eudragit RS 100, gum acacia, carnauba wax, stearyl alcohol, glyceryl monostearate and triethanol amine. Thus the granules were compressed and fourteen tablets formulations were prepared. All the physical parameters of granules and matrix tablets were studied including compatibility study. One commercial timed disintegration capsule was also included for study and comparison. The results of in vitro studies showed that sustained release matrix tablet might be prepared using carnauba wax, stearyl alcohol, triethanol amine and magnesium stearate.

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

PubMed

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

2005-01-01

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

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

PubMed

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

Dynamic bacterial and fungal microbiomes during sweet sorghum ensiling impact bioethanol production.

PubMed

Gallagher, Daniella; Parker, David; Allen, Damian J; Tsesmetzis, Nicolas

2018-05-23

Significant low-cost biofuel production volumes could be achieved from commercial-scale silage by redirecting lactic acid fermentation to ethanol production. A temporal metagenomic analysis on ensiled sweet sorghum inoculated with an ethanologenic yeast has been conducted to understand the underlying microbial processes during bioethanol production. Individual silage buckets approximating silage piles were prepared with freshly harvested material and supplemented with ethanologenic yeast, sulfuric acid or both. The ensiling progress was assessed using high performance liquid chromatography, microbial taxonomic identification and abundance. The combined treatment with Saccharomyces and acid led to a steady reduction of bacterial abundance and microbial diversity with Lactobacillus becoming the dominant genus during the late timepoints. Furthermore, the addition of acid to inhibit bacterial growth hindered Saccharomyces ability to compete with native yeasts like Candida. Knowledge of the response of the in-situ microbial community to the various treatments during ensiling will help improve current methodologies for bioethanol production. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

The effect of varieties on cotton wax as it relates to cotton quality parameters

USDA-ARS?s Scientific Manuscript database

Cotton wax is one of the non-cellulosic components found on the surfaces of cotton. It is important in dyeing and processing quality. This investigation was carried out to study the yield of wax on the surface of cottons by performing two methods: Soxhlet extractions and accelerated solvent extracti...

Antibiotics and Bacterial Resistance in the 21st Century

PubMed Central

Fair, Richard J; Tor, Yitzhak

2014-01-01

Dangerous, antibiotic resistant bacteria have been observed with increasing frequency over the past several decades. In this review the factors that have been linked to this phenomenon are addressed. Profiles of bacterial species that are deemed to be particularly concerning at the present time are illustrated. Factors including economic impact, intrinsic and acquired drug resistance, morbidity and mortality rates, and means of infection are taken into account. Synchronously with the waxing of bacterial resistance there has been waning antibiotic development. The approaches that scientists are employing in the pursuit of new antibacterial agents are briefly described. The standings of established antibiotic classes as well as potentially emerging classes are assessed with an emphasis on molecules that have been clinically approved or are in advanced stages of development. Historical perspectives, mechanisms of action and resistance, spectrum of activity, and preeminent members of each class are discussed. PMID:25232278

Development and Properties of a Wax Ester Hydrolase in the Cotyledons of Jojoba Seedlings 1

PubMed Central

Huang, Anthony H. C.; Moreau, Robert A.; Liu, Kitty D. F.

1978-01-01

The activity of a wax ester hydrolase in the cotyledons of jojoba (Simmondsia chinensis) seedlings increased drastically during germination, parallel to the development of the gluconeogenic process. The enzyme at its peak of development was obtained in association with the wax body membrane, and its properties were studied. It had an optimal activity at alkaline pH (8.5-9). The apparent Km value for N-methylindoxylmyristate was 93 μM. It was stable at 40 C for 30 min but was inactivated at higher temperature. Various divalent cations and ethylenediaminetetraacetate had little effect on the activity. p-Chloromercuribenzoate was a strong inhibitor of the enzyme activity, and its effect was reversed by subsequent addition of dithiothreitol. It had a broad substrate specificity with highest activities on monoglycerides, wax esters, and the native substrate (jojoba wax). PMID:16660288

BraLTP1, a Lipid Transfer Protein Gene Involved in Epicuticular Wax Deposition, Cell Proliferation and Flower Development in Brassica napus

PubMed Central

Liu, Fang; Xiong, Xiaojuan; Wu, Lei; Fu, Donghui; Hayward, Alice; Zeng, Xinhua; Cao, Yinglong; Wu, Yuhua; Li, Yunjing; Wu, Gang

2014-01-01

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. PMID:25314222

Wax Modeling and Image Analysis for Classroom-Scale Lava Flow Simulations.

NASA Astrophysics Data System (ADS)

Rader, E. L.; Clarke, A. B.; Vanderkluysen, L.

2016-12-01

The use of polyethylene glycol wax (PEG 600) as an analog for lava allows for a visual representation of the complex physical process occurring in natural lava flows, including cooling, breakouts, and crust and lobe formation. We used a series of cameras positioned around a tank filled with chilled water as a lab bench to observe and quantify lava flow morphology and motion. A peristaltic pump connected to a vent at the base of the tank delivered dyed wax simulating effusive eruptions similar to those of Kilauea in Hawai`i. By varying the eruptive conditions such as wax temperature and eruption rate, students can observe how the crust forms on wax flows, how different textures result, and how a flow field evolves with time. Recorded footage of the same `eruption' can then be quantitatively analyzed using free software like ImageJ and Tracker to quantify time-series of spreading rate, change in height, and appearance of different surface morphologies. Additional dye colors can be added periodically to further illustrate how lava is transported from the vent to the periphery of a flow field (e.g., through a tube system). Data collected from this activity can be compared to active lava flow footage from Hawai`i and with numerical models of lava flow propagation, followed by discussions of the application of these data and concepts to predicting the behavior of lava in hazard management situations and interpreting paleomagnetic, petrologic, and mapping of older eruptions.

Particulate pollutants are capable to 'degrade' epicuticular waxes and to decrease the drought tolerance of Scots pine (Pinus sylvestris L.).

PubMed

Burkhardt, Juergen; Pariyar, Shyam

2014-01-01

Air pollution causes the amorphous appearance of epicuticular waxes in conifers, usually called wax 'degradation' or 'erosion', which is often correlated with tree damage symptoms, e.g., winter desiccation. Previous investigations concentrated on wax chemistry, with little success. Here, we address the hypothesis that both 'wax degradation' and decreasing drought tolerance of trees may result from physical factors following the deposition of salt particles onto the needles. Pine seedlings were sprayed with dry aerosols or 50 mM solutions of different salts. The needles underwent humidity changes within an environmental scanning electron microscope, causing salt expansion on the surface and into the epistomatal chambers. The development of amorphous wax appearance by deliquescent salts covering tubular wax fibrils was demonstrated. The minimum epidermal conductance of the sprayed pine seedlings increased. Aerosol deposition potentially 'degrades' waxes and decreases tree drought tolerance. These effects have not been adequately considered thus far in air pollution research. Copyright © 2013 Elsevier Ltd. All rights reserved.

Overexpression of the Transcription Factors GmSHN1 and GmSHN9 Differentially Regulates Wax and Cutin Biosynthesis, Alters Cuticle Properties, and Changes Leaf Phenotypes in Arabidopsis.

PubMed

Xu, Yangyang; Wu, Hanying; Zhao, Mingming; Wu, Wang; Xu, Yinong; Gu, Dan

2016-04-21

SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely characterized. In this study, 10 homologs of Arabidopsis SHN genes were identified from soybean. These homologs were different in gene structures and organ expression patterns. Constitutive expression of each of the soybean SHN genes in Arabidopsis led to different leaf phenotypes, as well as different levels of glossiness on leaf surfaces. Overexpression of GmSHN1 and GmSHN9 in Arabidopsis exhibited 7.8-fold and 9.9-fold up-regulation of leaf cuticle wax productions, respectively. C31 and C29 alkanes contributed most to the increased wax contents. Total cutin contents of leaves were increased 11.4-fold in GmSHN1 overexpressors and 5.7-fold in GmSHN9 overexpressors, mainly through increasing C16:0 di-OH and dioic acids. GmSHN1 and GmSHN9 also altered leaf cuticle membrane ultrastructure and increased water loss rate in transgenic Arabidopsis plants. Transcript levels of many wax and cutin biosynthesis and leaf development related genes were altered in GmSHN1 and GmSHN9 overexpressors. Overall, these results suggest that GmSHN1 and GmSHN9 may differentially regulate the leaf development process as well as wax and cutin biosynthesis.

The Polyketide Components of Waxes and the Cer-cqu Gene Cluster Encoding a Novel Polyketide Synthase, the β-Diketone Synthase, DKS

PubMed Central

von Wettstein-Knowles, Penny

2017-01-01

The primary function of the outermost, lipophilic layer of plant aerial surfaces, called the cuticle, is preventing non-stomatal water loss. Its exterior surface is often decorated with wax crystals, imparting a blue–grey color. Identification of the barley Cer-c, -q and -u genes forming the 101 kb Cer-cqu gene cluster encoding a novel polyketide synthase—the β-diketone synthase (DKS), a lipase/carboxyl transferase, and a P450 hydroxylase, respectively, establishes a new, major pathway for the synthesis of plant waxes. The major product is a β-diketone (14,16-hentriacontane) aliphatic that forms long, thin crystalline tubes. A pathway branch leads to the formation of esterified alkan-2-ols. PMID:28698520

The Polyketide Components of Waxes and the Cer-cqu Gene Cluster Encoding a Novel Polyketide Synthase, the β-Diketone Synthase, DKS.

PubMed

von Wettstein-Knowles, Penny

2017-07-10

The primary function of the outermost, lipophilic layer of plant aerial surfaces, called the cuticle, is preventing non-stomatal water loss. Its exterior surface is often decorated with wax crystals, imparting a blue-grey color. Identification of the barley Cer-c , -q and -u genes forming the 101 kb Cer-cqu gene cluster encoding a novel polyketide synthase-the β-diketone synthase (DKS), a lipase/carboxyl transferase, and a P450 hydroxylase, respectively, establishes a new, major pathway for the synthesis of plant waxes. The major product is a β-diketone (14,16-hentriacontane) aliphatic that forms long, thin crystalline tubes. A pathway branch leads to the formation of esterified alkan-2-ols.

Death Becomes Them: Bacterial Community Dynamics and Stilbene Antibiotic Production in Cadavers of Galleria mellonella Killed by Heterorhabditis and Photorhabdus spp.

PubMed Central

Wollenberg, Amanda C.; Slough, Greg; Hoinville, Megan E.

2016-01-01

ABSTRACT Insect larvae killed by entomopathogenic nematodes are thought to contain bacterial communities dominated by a single bacterial genus, that of the nematode's bacterial symbiont. In this study, we used next-generation sequencing to profile bacterial community dynamics in greater wax moth (Galleria mellonella) larvae cadavers killed by Heterorhabditis nematodes and their Photorhabdus symbionts. We found that, although Photorhabdus strains did initially displace an Enterococcus-dominated community present in uninfected G. mellonella insect larvae, the cadaver community was not static. Twelve days postinfection, Photorhabdus shared the cadaver with Stenotrophomonas species. Consistent with this result, Stenotrophomonas strains isolated from infected cadavers were resistant to Photorhabdus-mediated toxicity in solid coculture assays. We isolated and characterized a Photorhabdus-produced antibiotic from G. mellonella cadavers, produced it synthetically, and demonstrated that both the natural and synthetic compounds decreased G. mellonella-associated Enterococcus growth, but not Stenotrophomonas growth, in vitro. Finally, we showed that the Stenotrophomonas strains described here negatively affected Photorhabdus growth in vitro. Our results add an important dimension to a broader understanding of Heterorhabditis-Photorhabdus biology and also demonstrate that interspecific bacterial competition likely characterizes even a theoretically monoxenic environment, such as a Heterorhabditis-Photorhabdus-parasitized insect cadaver. IMPORTANCE Understanding, and eventually manipulating, both human and environmental health depends on a complete accounting of the forces that act on and shape microbial communities. One of these underlying forces is hypothesized to be resource competition. A resource that has received little attention in the general microbiological literature, but likely has ecological and evolutionary importance, is dead/decaying multicellular organisms

Lubricant base oil and wax processing. [Glossary included

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sequeira, A. Jr.

1994-01-01

This book provides state-of-the-art information on all processes currently used to manufacture lubricant base oils and waxes. It furnishes helpful lists of conversion factors, construction cost data, and process licensors, as well as a glossary of essential petroleum processing terms.

Production and Reutilization of Fluorescent Dissolved Organic Matter by a Marine Bacterial Strain, Alteromonas macleodii

PubMed Central

Goto, Shuji; Tada, Yuya; Suzuki, Koji; Yamashita, Youhei

2017-01-01

The recalcitrant fraction of marine dissolved organic matter (DOM) plays an important role in carbon storage on the earth’s surface. Bacterial production of recalcitrant DOM (RDOM) has been proposed as a carbon sequestration process. It is still unclear whether bacterial physiology can affect RDOM production. In this study, we conducted a batch culture using the marine bacterial isolate Alteromonas macleodii, a ubiquitous gammaproteobacterium, to evaluate the linkage between bacterial growth and DOM production. Glucose (1 mmol C L-1) was used as the sole carbon source, and the bacterial number, the DOM concentration in terms of carbon, and the excitation–emission matrices (EEMs) of DOM were monitored during the 168-h incubation. The incubation period was partitioned into the exponential growth (0–24 h) and stationary phases (24–168 h) based on the growth curve. Although the DOM concentration decreased during the exponential growth phase due to glucose consumption, it remained stable during the stationary phase, corresponding to approximately 4% of the initial glucose in terms of carbon. Distinct fluorophores were not evident in the EEMs at the beginning of the incubation, but DOM produced by the strain exhibited five fluorescent peaks during exponential growth. Two fluorescent peaks were similar to protein-like fluorophores, while the others could be categorized as humic-like fluorophores. All fluorophores increased during the exponential growth phase. The tryptophan-like fluorophore decreased during the stationary phase, suggesting that the strain reused the large exopolymer. The tyrosine-like fluorophore seemed to be stable during the stationary phase, implying that the production of tyrosine-containing small peptides through the degradation of exopolymers was correlated with the reutilization of the tyrosine-like fluorophore. Two humic-like fluorophores that showed emission maxima at the longer wavelength (525 nm) increased during the stationary phase

Characterization of Bacterial Communities in Selected Smokeless Tobacco Products Using 16S rDNA Analysis

PubMed Central

Tyx, Robert E.; Stanfill, Stephen B.; Keong, Lisa M.; Rivera, Angel J.; Satten, Glen A.; Watson, Clifford H.

2016-01-01

The bacterial communities present in smokeless tobacco (ST) products have not previously reported. In this study, we used Next Generation Sequencing to study the bacteria present in U.S.-made dry snuff, moist snuff and Sudanese toombak. Sample diversity and taxonomic abundances were investigated in these products. A total of 33 bacterial families from four phyla, Actinobacteria, Firmicutes, Proteobacteria and Bacteroidetes, were identified. U.S.-produced dry snuff products contained a diverse distribution of all four phyla. Moist snuff products were dominated by Firmicutes. Toombak samples contained mainly Actinobacteria and Firmicutes (Aerococcaceae, Enterococcaceae, and Staphylococcaceae). The program PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) was used to impute the prevalence of genes encoding selected bacterial toxins, antibiotic resistance genes and other pro-inflammatory molecules. PICRUSt also predicted the presence of specific nitrate reductase genes, whose products can contribute to the formation of carcinogenic nitrosamines. Characterization of microbial community abundances and their associated genomes gives us an indication of the presence or absence of pathways of interest and can be used as a foundation for further investigation into the unique microbiological and chemical environments of smokeless tobacco products. PMID:26784944

The Extended Community-Level Effects of Genetic Variation in Foliar Wax Chemistry in the Forest Tree Eucalyptus globulus.

PubMed

Gosney, Benjamin; O'Reilly-Wapstra, Julianne; Forster, Lynne; Whiteley, Carmen; Potts, Brad

2017-05-01

Genetic variation in foundation trees can influence dependent communities, but little is known about the mechanisms driving these extended genetic effects. We studied the potential chemical drivers of genetic variation in the dependent foliar community of the focal tree Eucalyptus globulus. We focus on the role of cuticular waxes and compare the effects to that of the terpenes, a well-studied group of secondary compounds known to be bioactive in eucalypts. The canopy community was quantified based on the abundance of thirty-nine distinctive arthropod and fungal symptoms on foliar samples collected from canopies of 246 progeny from 13 E. globulus sub-races grown in a common garden trial. Cuticular waxes and foliar terpenes were quantified using gas chromatography - mass spectrometry (GC-MC). A total of 4 of the 13 quantified waxes and 7 of the 16 quantified terpenes were significantly associated with the dependent foliar community. Variation in waxes explained 22.9% of the community variation among sub-races, which was equivalent to that explained by terpenes. In combination, waxes and terpenes explained 35% of the genetic variation among sub-races. Only a small proportion of wax and terpene compounds showing statistically significant differences among sub-races were implicated in community level effects. The few significant waxes have previously shown evidence of divergent selection in E. globulus, which signals that adaptive variation in phenotypic traits may have extended effects. While highlighting the role of the understudied cuticular waxes, this study demonstrates the complexity of factors likely to lead to community genetic effects in foundation trees.

Influence of putrescine and carnauba wax on functional and sensory quality of pomegranate (Punica granatum L.) fruits during storage.

PubMed

Barman, Kalyan; Asrey, Ram; Pal, R K; Kaur, Charanjit; Jha, S K

2014-01-01

Functional properties (anthocyanins, antioxidant, ascorbic acid and tannin) and sensory score were determined in pomegranate fruits at two storage temperatures (3 and 5 °C) after treatment with 2 mM putrescine and 1 : 10 carnauba wax (carnauba wax : water). The treatments (putrescine and carnauba wax) were given by immersion method followed by storage up to 60 days. Both treatments retained significantly higher anthocyanins, antioxidant, ascorbic acid, tannin and sensory qualities as compared with control fruits under both the storage conditions. Combined application of putrescine + carnauba wax showed better response in retaining functional properties than putrescine treated or nontreated fruits. The impacts of putrescine and carnauba wax treatments were found more pronounced after 30 days at 3-5 °C storage temperature in retaining functional and sensory qualities. After 60 days of storage, putrescine + carnauba wax retained about 25% higher antioxidant activity both at 3 and 5 °C storage temperatures.

Molecular Characterization of TaFAR1 Involved in Primary Alcohol Biosynthesis of Cuticular Wax in Hexaploid Wheat.

PubMed

Wang, Yong; Wang, Meiling; Sun, Yulin; Hegebarth, Daniela; Li, Tingting; Jetter, Reinhard; Wang, Zhonghua

2015-10-01

Cuticular waxes are complex mixtures of very long chain (VLC) fatty acids and their derivatives in which primary alcohols are the most abundant components in the leaf surface of common wheat (Triticum aestivum L.). However, the genes involved in primary alcohol biosynthesis in wheat are still largely unknown. Here we identified, via a homology-based approach, the TaFAR1 gene belonging to the fatty acyl-CoA reductases (FARs) from wheat. Heterologous expression of TaFAR1 in yeast (Saccharomyces cerevisiae) and in the Arabidopsis (Arabidopsis thaliana) cer4-3 mutant afforded production of C22 primary alcohol and C22-C24 primary alcohols, respectively, and transgenic expression of TaFAR1 in tomato (Solanum lycopersicum) cv MicroTom leaves and fruits resulted in the accumulation of C26-C30 primary alcohols and C30-C34 primary alcohols, respectively. The TaFAR1 protein was localized to the endoplasmic reticulum (ER) in rice (Oryza sativa L.) leaf protoplasts. Moreover, the TaFAR1 expression pattern across various organs correlated with the levels of primary alcohols accumulating in corresponding waxes, and with the presence of platelet-shaped epicuticular wax crystals formed by primary alcohols. A nullisomic-tetrasomic wheat line lacking TaFAR1 had significantly reduced levels of primary alcohols in its leaf blade and anther wax. TaFAR1 was located on chromosome 4AL and appeared to be highly conserved, with only one haplotype among 32 wheat cultivars. Finally, TaFAR1 expression was induced by drought and cold stress in an ABA-dependent manner. Taken together, our results show that TaFAR1 is an active enzyme forming primary alcohols destined for the wheat cuticle. © 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.

["Norwegian scabies" in a wax model at the Pathology Museum of the University of Florence].

PubMed

Nesi, Gabriella; Santi, Raffaella; Sestini, Serena; De Giorgi, Vincenzo; Taddei, Gian Luigi

2008-01-01

The reproduction in wax of anatomic specimens is considered a glorious Italian tradition, particularly in Florence. Indeed, the work of wax masters which was cultivated for ex-votos and statuary models, together with the development of anatomic studies under the guidance of Paolo Mascagni at the end of the eighteenth century, gave origin to several collections of waxes, among which the collection of the Museum of Anatomic Pathology holds undoubted interest. The so-called "leper", a full-scale reproduction by Luigi Calamai of a man affected with Norwegian scabies, a rare skin disease, is considered the symbol of the Museum.

Production of bacterial cellulose and enzyme from waste fiber sludge

PubMed Central

2013-01-01

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

Development of hydrophilic dental wax without surfactant using a non-thermal air atmospheric pressure plasma jet

NASA Astrophysics Data System (ADS)

Lee, Jung-Hwan; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

2014-06-01

Dental wax (DW), a low-melting and high-molecular-weight organic mixture, is widely used in dentistry for forming moulds of teeth. Hydrophilicity is an important property for DW, as a wet dental investment is used to surround the wax before wax burnout is performed. However, recent attempts to improve the hydrophilicity of DW using a surfactant have resulted in the reduced mechanical properties of the dental investment, leading to the failure of the dental restoration. This study applied a non-thermal air atmospheric pressure plasma jet (AAPPJ) for DW surface treatment and investigated its effect on both DW hydrophilicity and the dental investment's mechanical properties. The results showed that the application of the AAPPJ significantly improved the hydrophilicity of the DW, and that the results were similar to that of cleaner-treated DW using commercially available products with surfactant. A surface chemical analysis indicated that the improvement of hydrophilicity was related to an increase in the number of oxygen-related bonds on the DW surface following the removal of carbon hydrate in both AAPPJ and cleaner-treated DW. However, cleaner treatment compromised the mechanical property of the dental investment when the dental investment was in contact with the treated DW, while the AAPPJ treatment did not. Therefore, the use of AAPPJ to treat DW is a promising method for accurate dental restoration, as it induces an improvement in hydrophilicity without harming the dental investment.

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

PubMed

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

2018-04-10

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

Pre-aged plant waxes in tropical lake sediments and their influence on the chronology of molecular paleoclimate proxy records

NASA Astrophysics Data System (ADS)

Douglas, Peter M. J.; Pagani, Mark; Eglinton, Timothy I.; Brenner, Mark; Hodell, David A.; Curtis, Jason H.; Ma, Keith F.; Breckenridge, Andy

2014-09-01

Sedimentary records of plant-wax hydrogen (δDwax) and carbon (δ13Cwax) stable isotopes are increasingly applied to infer past climate change. Compound-specific radiocarbon analyses, however, indicate that long time lags can occur between the synthesis of plant waxes and their subsequent deposition in marginal marine sediments. The influence of these time lags on interpretations of plant-wax stable isotope records is presently unconstrained, and it is unclear whether such time lags also affect lacustrine sediments. We present compound-specific radiocarbon (14Cwax) data for n-alkanoic acid plant waxes (n-C26 to n-C32) from: (1) a sediment core from Lake Chichancanab, Yucatan Peninsula, Mexico, (2) soils in the Lake Chichancanab catchment, and (3) surface sediments from three other lakes in southeastern Mexico and northern Guatemala. 14Cwax ages in the surface sediments are consistently older than modern, and may be negatively correlated with mean annual precipitation and positively correlated with lake catchment area. 14Cwax ages in soils surrounding Lake Chichancanab increase with soil depth, consistent with deep, subsoil horizons being the primary source of lacustrine aged plant waxes, which are likely delivered to lake sediments through subsurface transport. Plant waxes in the Lake Chichancanab core are 350-1200 years older than corresponding ages of bulk sediment deposition, determined by 14C dates on terrestrial plant macrofossils in the core. A δDwax time series is in closer agreement with other regional proxy hydroclimate records when a plant-wax 14C age model is applied, as opposed to the macrofossil-based core chronology. Inverse modeling of plant-wax age distribution parameters suggests that plant waxes in the Lake Chichancanab sediment core derive predominantly from millennial-age soil carbon pools that exhibit relatively little age variance (<200 years). Our findings demonstrate that high-temporal-resolution climate records inferred from stable isotope

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

PubMed

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

2016-11-01

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 (policosanols and long-chain aldehydes), volatile aroma profiles, and antioxidant activity of traditional NCS in granular form made from four different cane cultivars of Thailand. The total soluble solid, pH, color, and mineral content varied among the sugarcane cultivars, whereas there was no significant difference in the total sugar, phenolic and flavonoid content. The total policosanol, a cholesterol-lowering nutraceutical wax component, and long-chain aldehyde contents were similar in the NCS products amongst three cultivars, and ranged from 2.63 to 3.69 mg/100 g. The granulated NCS products, in which acetaldehyde and dimethyl sulfide were the main volatile compounds, gave less aroma components than traditional NCS. The use of different sugarcane cultivars thus influenced the quality attributes of granulated non-centrifugal sugar products.

Gourds: Bitter, Bottle, Wax, Snake, Sponge and Ridge

USDA-ARS?s Scientific Manuscript database

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 ...

Overexpression of the Transcription Factors GmSHN1 and GmSHN9 Differentially Regulates Wax and Cutin Biosynthesis, Alters Cuticle Properties, and Changes Leaf Phenotypes in Arabidopsis

PubMed Central

Xu, Yangyang; Wu, Hanying; Zhao, Mingming; Wu, Wang; Xu, Yinong; Gu, Dan

2016-01-01

SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely characterized. In this study, 10 homologs of Arabidopsis SHN genes were identified from soybean. These homologs were different in gene structures and organ expression patterns. Constitutive expression of each of the soybean SHN genes in Arabidopsis led to different leaf phenotypes, as well as different levels of glossiness on leaf surfaces. Overexpression of GmSHN1 and GmSHN9 in Arabidopsis exhibited 7.8-fold and 9.9-fold up-regulation of leaf cuticle wax productions, respectively. C31 and C29 alkanes contributed most to the increased wax contents. Total cutin contents of leaves were increased 11.4-fold in GmSHN1 overexpressors and 5.7-fold in GmSHN9 overexpressors, mainly through increasing C16:0 di-OH and dioic acids. GmSHN1 and GmSHN9 also altered leaf cuticle membrane ultrastructure and increased water loss rate in transgenic Arabidopsis plants. Transcript levels of many wax and cutin biosynthesis and leaf development related genes were altered in GmSHN1 and GmSHN9 overexpressors. Overall, these results suggest that GmSHN1 and GmSHN9 may differentially regulate the leaf development process as well as wax and cutin biosynthesis. PMID:27110768

Morphology and accumulation of epicuticular wax on needles of Douglas-fir (Pseudotsuga menziesii var. menziesii)

Treesearch

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...

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

PubMed Central

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

2015-01-01

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. PMID:26110895

75 FR 80843 - Petroleum Wax Candles From China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-23

... From China Determination On the basis of the record \\1\\ developed in the subject five-year review, the... candles from China would be likely to lead to continuation or recurrence of material injury to an industry... contained in USITC Publication 4207 (December 2010), entitled Petroleum Wax Candles from China...

Experimental investigations of thermophysical properties of some paraffin waxes industrially manufactured in Poland

NASA Astrophysics Data System (ADS)

Zbińkowski, Piotr; Zmywaczyk, Janusz; Koniorczyk, Piotr

2017-07-01

Phase-change materials (PCM) can be applied as a heat absorbing/releasing medium in passive cooling systems. Such systems can be used in cooling and temperature stabilization of electronic components, i.e., Li-ion batteries, photovoltaic modules or light emitting diodes (LED). In order to optimize heat transfer in passive cooling systems experimental studies of PCM thermophysical properties are necessary. A good PCM candidate for passive cooling systems may be paraffin waxes due to their relatively high latent heat of fusion (L 200 J.g-1), suitable for working of electronic devices range of melting temperatures (22 °C - 68 °C) and a reasonable price. However, their main drawback is a relatively low thermal conductivity k ranging from 0.148 W.m-1.K-1 to 0.358 W.m-1.K-1. In this paper were presented results of experimentally determined temperature characteristics of thermophysical parameters of four paraffin waxes industrially manufactured in Jasło/Poland by POLWAX. The density ρ of the test paraffin waxes determined at room temperature (20 °C) using a laboratory balance RADWAG X/60/220 comprised from 0.82 g.cm-3 to 0.94 g.cm-3. The thermal diffusivity κ of paraffin waxes was tested within temperature range from -50 °C to 30 °C every 20 °C interval using the NETZSCH LFA 467 HyperFlash. The test specimens having form of cylinder were 12.7 mm in diameter and 2.15 - 2.20 mm in height. Prior to the experiment the face and the back surface of each specimen were coated with a thin layer of graphite 33 having a thickness of several micrometers in accordance with the recommendation given by NETZSCH. The thermal diffusivity of the test paraffin waxes within temperature interval -40 °C - 20 °C was determined to be 0.083 mm2.s-1 to 0.216 mm2.s-1. Thermal effects and the apparent heat capacity cp of the tested materials were measured in the temperature range from -10 °C to 100 °C using the NETZSCH DSC 404 F1 Pegasus at 10 K.min-1 heating/cooling rates in an

Phage bacteriolysis, protistan bacterivory potential, and bacterial production in a freshwater reservoir: coupling with temperature.

PubMed

Pradeep Ram, A S; Boucher, D; Sime-Ngando, T; Debroas, D; Romagoux, J C

2005-07-01

Phage abundance and infection of bacterioplankton were studied from March to November 2003 in the Sep Reservoir (Massif Central, France), together with temperature, chlorophyll, bacteria (abundance and production), and heterotrophic nanoflagellates (abundance and potential bacterivory). Virus abundance (VA) ranged from 0.6 to 13 x 10(10) viruses l(-1), exceeding bacterial abundance (BA) approximately sixfold on average. In terms of carbon, viruses corresponded to up to 25% of bacterial biomass. A multiple regression model indicated that BA was the best predictor for VA (R(2) = 0.75). The frequency of infected bacteria (estimated from the percentage of visibly infected cells) varied from 1% to 32% and was best explained by a combination of temperature (R(2) = 0.20) and bacterial production (R(2) = 0.25). Viruses and flagellates contributed about equally to bacterial mortality. Both factors destroyed 55% of bacterial production, with a shift from phage bacteriolysis in early spring to protistan bacterivory in late summer. The vertical differences in most of the biological variables were not significant, contrasting with the seasonal differences (i.e., spring vs. summer-autumn). All biological variables under study were indeed significantly coupled to temperature. We regarded this to be the consequence of the enhanced discharge of the reservoir in 2003 (compared to previous years). This substantially weakened the stability and the thermal inertia of the water column, thereby establishing temperature as a stronger forcing factor in setting the conditions for optimal metabolic activity of microbial communities.

Rapid analysis of 13C in plant-wax n-alkanes for reconstruction of terrestrial vegetation signals from aquatic sediments

NASA Astrophysics Data System (ADS)

McDuffee, Kelsey E.; Eglinton, Timothy I.; Sessions, Alex L.; Sylva, Sean; Wagner, Thomas; Hayes, John M.

2004-10-01

Long-chain, odd-carbon-numbered C25 to C35 n-alkanes are characteristic components of epicuticular waxes produced by terrestrial higher plants. They are delivered to aquatic systems via eolian and fluvial transport and are preserved in underlying sediments. The isotopic compositions of these products can serve as records of past vegetation. We have developed a rapid method for stable carbon isotopic analyses of total plant-wax n-alkanes using a novel, moving-wire system coupled to an isotope-ratio mass spectrometer (MW-irMS). The n-alkane fractions are prepared from sediment samples by (1) saponification and extraction with organic solvents, (2) chromatographic separation using silica gel, (3) isolation of straight-chain carbon skeletons using a zeolite molecular sieve, and (4) oxidation and removal of unsaturated hydrocarbons with RuO4. Short-chain n-alkanes of nonvascular plant origin (wax n-alkanes. The amplitude of the variations was smaller, indicating contributions from non-plant-wax hydrocarbons, but the measurements revealed variations in carbon isotopic composition that are consistent with vegetation zones on the adjacent continent.

Rapid analysis of 13C in plant-wax n-alkanes for reconstruction of terrestrial vegetation signals from aquatic sediments

NASA Astrophysics Data System (ADS)

McDuffee, Kelsey E.; Eglinton, Timothy I.; Sessions, Alex L.; Sylva, Sean; Wagner, Thomas; Hayes, John M.

2004-10-01

Long-chain, odd-carbon-numbered C25 to C35n-alkanes are characteristic components of epicuticular waxes produced by terrestrial higher plants. They are delivered to aquatic systems via eolian and fluvial transport and are preserved in underlying sediments. The isotopic compositions of these products can serve as records of past vegetation. We have developed a rapid method for stable carbon isotopic analyses of total plant-wax n-alkanes using a novel, moving-wire system coupled to an isotope-ratio mass spectrometer (MW-irMS). The n-alkane fractions are prepared from sediment samples by (1) saponification and extraction with organic solvents, (2) chromatographic separation using silica gel, (3) isolation of straight-chain carbon skeletons using a zeolite molecular sieve, and (4) oxidation and removal of unsaturated hydrocarbons with RuO4. Short-chain n-alkanes of nonvascular plant origin (wax n-alkanes. The amplitude of the variations was smaller, indicating contributions from non-plant-wax hydrocarbons, but the measurements revealed variations in carbon isotopic composition that are consistent with vegetation zones on the adjacent continent.

Instant freezing of impacting wax drops

NASA Astrophysics Data System (ADS)

Ponomarenko, Alexandre; Virot, Emmanuel; Rubinstein, Shmuel

2015-11-01

We present the impact of hot liquid drops of wax on surfaces whose temperature is below the solidifying temperature of the drops. During the fall the drops remain mostly liquid, but upon impact, their temperature quickly decreases resulting in the solidification of the drop. Depending on the impact energy, drops size and the temperature difference between the drop and the surface this results in plethora of solid shapes: simple lenses, triangular drops, spherical caps and popped popcorn shapes.

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

PubMed

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.

Variations of Leaf Cuticular Waxes Among C3 and C4 Gramineae Herbs.

PubMed

He, Yuji; Gao, Jianhua; Guo, Na; Guo, Yanjun

2016-11-01

Modern C4 plants are commonly distributed in hot and dry environments whereas C3 plants predominate in cool and shade areas. At the outmost of plant surface, the deposition and chemical composition of cuticular waxes vary under different environmental conditions. However, whether such variation of cuticular wax is related to the distribution of C3 and C4 under different environmental conditions is still not clear. In this study, leaves of six C3 Gramineae herbs distributed in spring, Roegneria kamoji, Polypogon fugax, Poa annua, Avena fatua, Alopecurus aequalis, and Oplismenus undulatifolius, and four C4 and one C3 Gramineae herbs distributed in summer, Digitaria sanguinalis, Eleusine indica, Setaria viridis, S. plicata, and O. undulatifolius, were sampled and analyzed for cuticular wax. Plates were the main epicuticular wax morphology in both C3 and C4 plants except S. plicata. The plates melted in C4 plants but not in C3 plants. The total cuticular wax amounts in C4 plants were significantly lower than those in C3 plants, except for O. undulatifolius. Primary alcohols were the most abundant compounds in C3 plants, whereas n-alkanes were relatively the most abundant compounds in C4 plants. C 29 was the most abundant n-alkane in C3 plants except for O. undulatifolius, whereas the most abundant n-alkane was C 31 or C 33 in C4 plants. The average chain length (ACL) of n-alkanes was higher in C4 than in C3 plants, whereas the ACL of n-alkanoic acids was higher in C3 than C4 plants. The cluster analysis based on the distribution of n-alkanes clearly distinguished C3 and C4 plants into two groups, except for O. undulatifolius which was grouped with C4 plants. These results suggest that the variations of cuticular waxes among C3 and C4 Gramineae herbs are related to the distribution of C3 and C4 plants under different environmental conditions. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

The usage, occurrence and dietary intakes of white mineral oils and waxes in Europe.

PubMed

Tennant, D R

2004-03-01

Dietary exposures to mineral hydrocarbons were estimated from information about patterns of usage, concentrations in foods and quantities of foods consumed. An industry survey showed that the largest usage of food-grade white mineral oils was in plastics manufacture although the majority are used in non-food applications. The largest volumes of wax usage were in packaging. Conservative estimates indicated that daily intakes of white mineral oils ranged from 0.39 to 0.91 mg/kg bw/day for adults and from 0.75 to 1.77 mg/kg bw/day for children (mean and 97.5th percentiles). Total wax intakes ranged from 0.08 to 0.19 mg/kg bw/day for adults and 0.23 to 0.64 mg/kg bw/day for pre-school children. When usage factors were applied, estimates of chronic intakes of white oils were reduced to 0.09-0.20 mg/kg bw/day for adults and to 0.17-0.39 mg/kg bw/day for children. Total wax intakes were reduced to 0.01-0.02 mg/kg bw/day for adults and to 0.02-0.06 mg/kg bw/day for children. For white mineral oils the principal source of exposure for most consumers was imported de-dusted grain. The principal source of potential wax exposure was from glazing agents on confectionery. There was no evidence of intakes exceeding SCF ADIs for microcrystalline waxes or certain white mineral oils and levels of exposure were similar to those of naturally-occurring mineral hydrocarbons in foods.

Quantitative Determination of Wax Contamination in Polystyrene HIPE Foam Using Solid-State NMR

DOE PAGES

Cluff, Kyle James; Goodwin, Lynne Alese; Hamilton, Christopher Eric; ...

2017-11-29

Differences in molecular mobility between polystyrene foam and Brij-78 wax results in vast differences in the 1H nuclear magnetic resonance (NMR) linewidth. This allows for the convenient determination of wax content in the polystyrene foam components of inertial confinement fusion targets via solid-state NMR. Lastly, contamination levels as low as 0.1% are easily recognized and quantified, and the detection limit is calculated to be 0.02% even when only 32 transients are recorded.

Quantitative Determination of Wax Contamination in Polystyrene HIPE Foam Using Solid-State NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cluff, Kyle James; Goodwin, Lynne Alese; Hamilton, Christopher Eric

Differences in molecular mobility between polystyrene foam and Brij-78 wax results in vast differences in the 1H nuclear magnetic resonance (NMR) linewidth. This allows for the convenient determination of wax content in the polystyrene foam components of inertial confinement fusion targets via solid-state NMR. Lastly, contamination levels as low as 0.1% are easily recognized and quantified, and the detection limit is calculated to be 0.02% even when only 32 transients are recorded.

Pyrosequencing analysis for characterization of bacterial diversity in a soil as affected by integrated livestock-cotton production systems

USDA-ARS?s Scientific Manuscript database

Impacts of integrated livestock-crop production systems compared to specialized systems on soil bacterial diversity have not been well documented. We used a bacterial tag encoded FLX amplicon pyrosequencing (bTEFAP) method to evaluate bacterial diversity of a clay loam soil (Fine, mixed, thermic To...

Diversity of the dominant bacterial species on sliced cooked pork products at expiration date in the Belgian retail.

PubMed

Geeraerts, Wim; Pothakos, Vasileios; De Vuyst, Luc; Leroy, Frédéric

2017-08-01

Pork-based cooked products, such as cooked hams, are economically valuable foods that are vulnerable to bacterial spoilage, even when applying cooling and modified atmosphere packaging (MAP). Besides a common presence of Brochothrix thermosphacta, their microbiota are usually dominated by lactic acid bacteria (LAB). Yet, the exact LAB species diversity can differ considerably among products. In this study, 42 sliced cooked pork samples were acquired from three different Belgian supermarkets to map their bacterial heterogeneity. The community compositions of the dominant bacterial species were established by analysing a total of 702 isolates from selective agar media by (GTG) 5 -PCR fingerprinting followed by gene sequencing. Most of the isolates belonged to the genera Carnobacterium, Lactobacillus, and Leuconostoc, with Leuconostoc carnosum and Leuconostoc gelidum subsp. gelidum being the most dominant members. The diversity of the dominant bacterial species varied when comparing samples from different production facilities and, in some cases, even within the same product types. Although LAB consistently dominated the microbiota of sliced cooked pork products in the Belgian market, results indicated that bacterial diversity needs to be addressed on the level of product composition and batch variation. Dedicated studies will be needed to substantiate potential links between such variability and microbial composition. For instance, the fact that higher levels of lactobacilli were associated with the presence of potassium lactate (E326) may be suggestive of selective pressure but needs to be validated, as this finding referred to a single product only. Copyright © 2017 Elsevier Ltd. All rights reserved.

Soil water stress affects both cuticular wax content and cuticle-related gene expression in young saplings of maritime pine (Pinus pinaster Ait).

PubMed

Le Provost, Grégoire; Domergue, Frédéric; Lalanne, Céline; Ramos Campos, Patricio; Grosbois, Antoine; Bert, Didier; Meredieu, Céline; Danjon, Frédéric; Plomion, Christophe; Gion, Jean-Marc

2013-07-01

The cuticle is a hydrophobic barrier located at the aerial surface of all terrestrial plants. Recent studies performed on model plants, such as Arabidopsis thaliana, have suggested that the cuticle may be involved in drought stress adaptation, preventing non-stomatal water loss. Although forest trees will face more intense drought stresses (in duration and intensity) with global warming, very few studies on the role of the cuticle in drought stress adaptation in these long-lived organisms have been so far reported. This aspect was investigated in a conifer, maritime pine (Pinus pinaster Ait.), in a factorial design with two genetic units (two half-sib families with different growth rates) and two treatments (irrigated vs non-irrigated), in field conditions. Saplings were grown in an open-sided greenhouse and half were irrigated three times per week for two growing seasons. Needles were sampled three times per year for cuticular wax (composition and content) and transcriptome (of 11 genes involved in cuticle biosynthesis) analysis. Non-irrigated saplings (i) had a higher cuticular wax content than irrigated saplings and (ii) overexpressed most of the genes studied. Both these trends were more marked in the faster growing family. The higher cuticular wax content observed in the non-irrigated treatment associated with strong modifications in products from the decarbonylation pathway suggest that cuticular wax may be involved in drought stress adaptation in maritime pine. This study provides also a set of promising candidate genes for future forward genetic studies in conifers.

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

PubMed

Basta, A H; El-Saied, H

2009-12-01

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

Antiprotozoal activity of extracts and isolated triterpenoids of 'carnauba' (Copernicia prunifera) wax from Brazil.

PubMed

de Almeida, Buana C; Araújo, Bruno Q; Carvalho, Adonias A; Freitas, Sâmya Danielle L; Maciel, Dayany da S Alves; Ferreira, Ari José S; Tempone, Andre G; Martins, Ligia F; Alexandre, Tatiana R; Chaves, Mariana H; Lago, João Henrique G

2016-12-01

'Carnauba' wax is a natural product obtained from the processing of the powder exuded from Copernicia prunifera (Miller) H. E. Moore (Arecaceae). This material is widely used in the Brazilian folk medicine, including the treatment of rheumatism and syphilis. To investigate the antiprotozoal activity of hexane and EtOH extracts from the 'carnauba' wax as well as from the isolated compounds from the bioactive extracts. Two different samples of 'carnauba' (C. prunifera) waxes - types 1 and 4 - were individually extracted using hexane (EH) and EtOH (EE). Aliquots of hexane (type 1 - EH-1 and EH-4) and EtOH (type 4 - EE-1 and EE-4) extracts were tested against promastigote (2-200 μg/mL in DMSO during 48 h at 24 °C) and amastigote (3-150 μg/mL in DMSO during 120 h at 37 °C) forms of Leishmania infantum as well as against trypomastigote (3-150 μg/mL in DMSO during 24 h at 37 °C) forms of Trypanosoma cruzi. Bioactive extracts EH-1 and EE-4 were subjected to a bioactivity-guided fractionation to afford three dammarane-type triterpenoids (1-3). The in vitro antiprotozoal activities of the obtained compounds were evaluated as described above. Additionally, the cytotoxicity activity of compounds 1-3 against mammalian conjunctive cells (NCTC - 2-200 μg/mL in DMSO during 48 h at 37 °C) was determined. From the bioactive hexane and EtOH extracts from the 'carnauba' (C. prunifera) wax, were isolated three dammarane-type triterpenoids: (24R*)-methyldammar-25-ene-3β,20-diol (carnaubadiol, 1), (24R*)-methyldammara-20,25-dien-3-one (2) and (24R*)-methyldammara-20,25-dien-3α-ol (3). These compounds were identified based on the analysis of NMR and MS spectroscopic data. Compounds 1-3 were effective against the intracellular amastigotes of L. infantum, with IC 50 values ranging from 8 to 52 μM, while compounds 1 and 3 displayed activity against trypomastigote forms of T. cruzi with IC 50 values of 15 and 35 μM, respectively. The mammalian

Two bifunctional enzymes from the marine protist Thraustochytrium roseum: biochemical characterization of wax ester synthase/acyl-CoA:diacylglycerol acyltransferase activity catalyzing wax ester and triacylglycerol synthesis.

PubMed

Zhang, Nannan; Mao, Zejing; Luo, Ling; Wan, Xia; Huang, Fenghong; Gong, Yangmin

2017-01-01

Triacylglycerols (TAGs) and wax esters (WEs) are important neutral lipids which serve as energy reservoir in some plants and microorganisms. In recent years, these biologically produced neutral lipids have been regarded as potential alternative energy sources for biofuel production because of the increased interest on developing renewable and environmentally benign alternatives for fossil fuels. In bacteria, the final step in TAG and WE biosynthetic pathway is catalyzed by wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT). This bifunctional WS/DGAT enzyme is also a key enzyme in biotechnological production of liquid WE via engineering of plants and microorganisms. To date, knowledge about this class of biologically and biotechnologically important enzymes is mainly from biochemical characterization of WS/DGATs from Arabidopsis, jojoba and some bacteria that can synthesize both TAGs and WEs intracellularly, whereas little is known about WS/DGATs from eukaryotic microorganisms. Here, we report the identification and characterization of two bifunctional WS/DGAT enzymes (designated TrWSD4 and TrWSD5) from the marine protist Thraustochytrium roseum . Both TrWSD4 and TrWSD5 comprise a WS-like acyl-CoA acyltransferase domain and the recombinant proteins purified from Escherichia coli Rosetta (DE3) have substantial WS and lower DGAT activity. They exhibit WS activity towards various-chain-length saturated and polyunsaturated acyl-CoAs and fatty alcohols ranging from C 10 to C 18 . TrWSD4 displays WS activity with the lowest K m value of 0.14 μM and the highest k cat / K m value of 1.46 × 10 5  M -1  s -1 for lauroyl-CoA (C 12:0 ) in the presence of 100 μM hexadecanol, while TrWSD5 exhibits WS activity with the lowest K m value of 0.96 μM and the highest k cat / K m value of 9.83 × 10 4  M -1  s -1 for decanoyl-CoA (C 10:0 ) under the same reaction condition. Both WS/DGAT enzymes have the highest WS activity at 37 and 47�

The moss Funaria hygrometrica has cuticular wax similar to vascular plants, with distinct composition on leafy gametophyte, calyptra and sporophyte capsule surfaces.

PubMed

Busta, Lucas; Budke, Jessica M; Jetter, Reinhard

2016-09-01

Aerial surfaces of land plants are covered with a waxy cuticle to protect against water loss. The amount and composition of cuticular waxes on moss surfaces had rarely been investigated. Accordingly, the degree of similarity between moss and vascular plant waxes, and between maternal and offspring moss structure waxes is unknown. To resolve these issues, this study aimed at providing a comprehensive analysis of the waxes on the leafy gametophyte, gametophyte calyptra and sporophyte capsule of the moss Funaria hygrometrica Waxes were extracted from the surfaces of leafy gametophytes, gametophyte calyptrae and sporophyte capsules, separated by gas chromatography, identified qualitatively with mass spectrometry, and quantified with flame ionization detection. Diagnostic mass spectral peaks were used to determine the isomer composition of wax esters. The surfaces of the leafy gametophyte, calyptra and sporophyte capsule of F. hygrometrica were covered with 0·94, 2·0 and 0·44 μg cm(-2) wax, respectively. While each wax mixture was composed of mainly fatty acid alkyl esters, the waxes from maternal and offspring structures had unique compositional markers. β-Hydroxy fatty acid alkyl esters were limited to the leafy gametophyte and calyptra, while alkanes, aldehydes and diol esters were restricted to the sporophyte capsule. Ubiquitous fatty acids, alcohols, fatty acid alkyl esters, aldehydes and alkanes were all found on at least one surface. This is the first study to determine wax coverage (μg cm(-2)) on a moss surface, enabling direct comparisons with vascular plants, which were shown to have an equal amount or more wax than F. hygrometrica Wax ester biosynthesis is of particular importance in this species, and the ester-forming enzyme(s) in different parts of the moss may have different substrate preferences. Furthermore, the alkane-forming wax biosynthesis pathway, found widely in vascular plants, is active in the sporophyte capsule, but not in the leafy

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

PubMed

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.

Bacterial avirulence genes.

PubMed

Leach, J E; White, F F

1996-01-01

Although more than 30 bacterial avirulence genes have been cloned and characterized, the function of the gene products in the elictitation of resistance is unknown in all cases but one. The product of avrD from Pseudomonas syringae pv. glycinea likely functions indirectly to elicit resistance in soybean, that is, evidence suggests the gene product is an enzyme involved in elicitor production. In most if not all cases, bacterial avirulence gene function is dependent on interactions with the hypersensitive response and pathogenicity (hrp) genes. Many hrp genes are similar to genes involved in delivery of pathogenicity factors in mammalian bacterial pathogens. Thus, analogies between mammalian and plant pathogens may provide needed clues to elucidate how virulence gene products control induction of resistance.

Integrating Science in Your Classroom: Wax On, Wane Off

ERIC Educational Resources Information Center

Cowens, John

2006-01-01

The changing figures of the waxing and waning moon are among the most conspicuous of celestial phenomena and were some of the first to be understood. This paper describes a classroom activity designed to teach children about the phases of the moon.

Bacterial production and their role in the removal of dissolved organic matter from tributaries of drinking water reservoirs.

PubMed

Kamjunke, Norbert; Oosterwoud, Marieke R; Herzsprung, Peter; Tittel, Jörg

2016-04-01

Enhanced concentrations of dissolved organic matter (DOM) in freshwaters are an increasing problem in drinking water reservoirs. In this study we investigated bacterial DOM degradation rates in the tributaries of the reservoirs and tested the hypotheses that (1) DOM degradation is high enough to decrease DOM loads to reservoirs considerably, (2) DOM degradation is affected by stream hydrology, and (3) phosphorus addition may stimulate bacterial DOM degradation. Bacterial biomass production, which was used as a measure of DOM degradation, was highest in summer, and was usually lower at upstream than at downstream sites. An important proportion of bacterial production was realized in epilithic biofilms. Production of planktonic and biofilm bacteria was related to water temperature. Planktonic production weakly correlated to DOM quality and to total phosphorus concentration. Addition of soluble reactive phosphorus did not stimulate bacterial DOM degradation. Overall, DOM was considerably degraded in summer at low discharge levels, whereas degradation was negligible during flood events (when DOM load in reservoirs was high). The ratio of DOM degradation to total DOM release was negatively related to discharge. On annual average, only 0.6-12% of total DOM released by the catchments was degraded within the tributaries. Copyright © 2016 Elsevier B.V. All rights reserved.

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

PubMed

Grossmann, S; Dieckmann, G S

1994-08-01

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

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

PubMed

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

2017-12-01

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

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

PubMed

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

2018-02-20

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

Comparison of various extraction methods for policosanol from rice bran wax and establishment of chromatographic fingerprint of policosanol.

PubMed

Wang, Mei-Fei; Lian, Hong-Zhen; Mao, Li; Zhou, Jing-Ping; Gong, Hui-Juan; Qian, Bao-Yong; Fang, Yan; Li, Jie

2007-07-11

A capillary gas chromatographic (GC) method has been developed for the separation and determination of policosanol components extracted from rice bran wax. A Varian CP-sil 8 CB column was employed, and an oven temperature was programmed. Gas chromatography-mass spectrometry (GC-MS) was used to identify the composition of policosanol. Quantitative analysis was carried out by means of hydrogen flame ionization detector (FID) with dinonyl phthalate (DNP) as internal standard. The results indicated that the extract obtained by dry saponification has the highest contents of octacosanol and triacontanol among extracts by all used extraction methods including dry saponification, saponification in alcohol, saponification in water (neutralized and non-neutralized), and transesterification. Meanwhile, the GC-MS fingerprint of policosanol extracted by dry saponification has been established. Euclidean distance similarity calculation showed remarkable consistency of compositions and contents among 12 batches of policosanol from a rice bran wax variety. This protocol provided a rapid and feasible method for quality control of policosanol products.

The effects of magnetic fields on carnauba wax electret formation

NASA Astrophysics Data System (ADS)

Clator, Irvin G.

1987-08-01

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

ATP citrate lyase activity is post-translationally regulated by sink strength and impacts the wax, cutin and rubber biosynthetic pathways.

PubMed

Xing, Shufan; van Deenen, Nicole; Magliano, Pasqualina; Frahm, Lea; Forestier, Edith; Nawrath, Christiane; Schaller, Hubert; Gronover, Christian S; Prüfer, Dirk; Poirier, Yves

2014-07-01

Cytosolic acetyl-CoA is involved in the synthesis of a variety of compounds, including waxes, sterols and rubber, and is generated by the ATP citrate lyase (ACL). Plants over-expressing ACL were generated in an effort to understand the contribution of ACL activity to the carbon flux of acetyl-CoA to metabolic pathways occurring in the cytosol. Transgenic Arabidopsis plants synthesizing the polyester polyhydroxybutyrate (PHB) from cytosolic acetyl-CoA have reduced growth and wax content, consistent with a reduction in the availability of cytosolic acetyl-CoA to endogenous pathways. Increasing the ACL activity via the over-expression of the ACLA and ACLB subunits reversed the phenotypes associated with PHB synthesis while maintaining polymer synthesis. PHB production by itself was associated with an increase in ACL activity that occurred in the absence of changes in steady-state mRNA or protein level, indicating a post-translational regulation of ACL activity in response to sink strength. Over-expression of ACL in Arabidopsis was associated with a 30% increase in wax on stems, while over-expression of a chimeric homomeric ACL in the laticifer of roots of dandelion led to a four- and two-fold increase in rubber and triterpene content, respectively. Synthesis of PHB and over-expression of ACL also changed the amount of the cutin monomer octadecadien-1,18-dioic acid, revealing an unsuspected link between cytosolic acetyl-CoA and cutin biosynthesis. Together, these results reveal the complexity of ACL regulation and its central role in influencing the carbon flux to metabolic pathways using cytosolic acetyl-CoA, including wax and polyisoprenoids. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

The acyl desaturase CER17 is involved in producing wax unsaturated primary alcohols and cutin monomers

USDA-ARS?s Scientific Manuscript database

We report here n-6 mono-unsaturated primary alcohols (the C26:1, C28:1, and C30:1 homologues) in the cuticular waxes of Arabidopsis inflorescence stem, a class of wax compound not previously reported in Arabidopsis. Further, we used mutation and transgenic complementation analyses to demonstrate tha...

Luffa sponge offsets the negative effects of aeration on bacterial cellulose production.

PubMed

Krusong, W; Kerdpiboon, S; Pornpukdeewattana, S; Jindaprasert, A

2016-12-01

To offset the negative effects of aeration on bacterial cellulose (BC) production by acetic acid bacteria using enmeshed cellulose microfibrils (CM) on luffa sponge matrices (LSM). The CM were enmeshed on LSM (LSM-CM). The optimal amount of LSM-CM was determined for BC production under aerated conditions. Without LSM-CM, no BC was produced in seven out of nine production cycles at the highest aeration rate (9 l min -1 ). However, with 0·5% LSM-CM and an aeration rate of 3 l min -1 , a satisfactory oxygen transfer coefficient was achieved, and also a good yield of BC (5·24 g l -1 ). Moreover, the LSM-CM was able to be recycled through nine consecutive BC production cycles. The highest BC yields (from 5·8 ± 0·4 to 6·6 ± 0·4 g l -1 ) were associated with high bacterial biomass and this was confirmed by scanning electron microscopy. We confirm that LSM-CM works well as a starter. Microenvironments low in dissolved oxygen within the matrices of LSM-CM are important for BC production under aeration conditions. The LSM-CM provides a microenvironment which offsets the negative effects of aeration on BC production. A sustainable, economic process for mass BC production is described using recycled LSM-CM with aeration. © 2016 The Society for Applied Microbiology.

Hot Wax Sweeps Debris From Narrow Passages

NASA Technical Reports Server (NTRS)

Ricklefs, Steven K.

1990-01-01

Safe and effective technique for removal of debris and contaminants from narrow passages involves entrainment of undesired material in thermoplastic casting material. Semisolid wax slightly below melting temperature pushed along passage by pressurized nitrogen to remove debris. Devised to clean out fuel passages in main combustion chamber of Space Shuttle main engine. Also applied to narrow, intricate passages in internal-combustion-engine blocks, carburetors, injection molds, and other complicated parts.

Synchrotron WAXS and XANES studies of silica (SiO2) powders synthesized from Indonesian natural sands

NASA Astrophysics Data System (ADS)

Muchlis, Khairanissa; Aini Fauziyah, Nur; Soontaranon, Siriwat; Limpirat, Wanwisa; Pratapa, Suminar

2017-01-01

In this study, we have investigated polymorphic silica (SiO2) powders using, Wide Angle X-ray Scattering (WAXS) and X-Ray Absorption Near Edge Spectroscopy (XANES), laboratory X-Ray Diffraction (XRD) instruments. The WAXS and XANES spectra were collected using synchrotron radiation at Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. The silica powders were obtained by processing silica sand from Tanah Laut, South Kalimantan, Indonesia. Purification process of silica sand was done by magnetic separation and immersion with HCl. The purification step was needed to reduce impurity or undesirable non Si elements. Three polymorphs of silica were produced, i.e. amorphous phase (A), quartz (B), and cristobalite (C). WAXS profile for each phase was presented in terms of intensity vs. 2θ prior to analyses. Both XRD (λCuKα=1.54056 Å) and WAXS (λ=1.09 Å) patttern show that (1) A sample contains no crystallites, (2) B sample is monophasic, contains only quartz, and (3) C sample contains cristobalite and trydimite. XRD quantitative analysis using Rietica gave 98,8 wt% cristobalite, while the associated WAXS data provided 98.7 wt% cristobalite. Si K-edge XANES spectra were measured at energy range 1840 to 1920 eV. Qualitatively, the pre-edge and edge features for all phases are similar, but their main peaks in the post-edge region are different.

Quantitative, nondestructive assessment of beech scale (Hemiptera: Cryptococcidae) density using digital image analysis of wax masses.

PubMed

Teale, Stephen A; Letkowski, Steven; Matusick, George; Stehman, Stephen V; Castello, John D

2009-08-01

Beech scale, Cryptococcus fagisuga Lindinger, is a non-native invasive insect associated with beech bark disease. A quantitative method of measuring viable scale density at the levels of the individual tree and localized bark patches was developed. Bark patches (10 cm(2)) were removed at 0, 1, and 2 m above the ground and at the four cardinal directions from 13 trees in northern New York and 12 trees in northern Michigan. Digital photographs of each patch were made, and the wax mass area was measured from two random 1-cm(2) subsamples on each bark patch using image analysis software. Viable scale insects were counted after removing the wax under a dissecting microscope. Separate regression analyses at the whole tree level for the New York and Michigan sites each showed a strong positive relationship of wax mass area with the number of underlying viable scale insects. The relationships for the New York and Michigan data were not significantly different from each other, and when pooling data from the two sites, there was still a significant positive relationship between wax mass area and the number of scale insects. The relationships between viable scale insects and wax mass area were different at the 0-, 1-, and 2-m sampling heights but do not seem to affect the relationship. This method does not disrupt the insect or its interactions with the host tree.

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

PubMed Central

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

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

PubMed

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.

Variation for epicuticular waxes and thrips resistance in onion

USDA-ARS?s Scientific Manuscript database

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...

Effect of emulsifier type and concentration, aqueous phase volume and wax ratio on physical, material and mechanical properties of water in oil lipsticks.

PubMed

Beri, A; Norton, J E; Norton, I T

2013-12-01

Water-in-oil emulsions in lipsticks could have the potential to improve moisturizing properties and deliver hydrophilic molecules to the lips. The aims of this work were (i) to investigate the effect of emulsifier type (polymer vs. monomer, and saturated vs. unsaturated chain) and concentration on droplet size and (ii) to investigate the effect of wax ratio (carnauba wax, microcrystalline wax, paraffin wax and performalene) and aqueous phase volume on material properties (Young's modulus, point of fracture, elastic modulus and viscous modulus). Emulsion formation was achieved using a high shear mixer. Results showed that the saturated nature of the emulsifier had very little effect on droplet size, neither did the use of an emulsifier with a larger head group (droplet size ~18-25 μm). Polyglycerol polyricinoleate (PGPR) resulted in emulsions with the smallest droplets (~3-5 μm), as expected from previous studies that show that it produces a thick elastic interface. The results also showed that both Young's modulus and point of fracture increase with increasing percentage of carnauba wax (following a power law dependency of 3), but decrease with increasing percentage of microcrystalline wax, suggesting that the carnauba wax is included in the overall wax network formed by the saturated components, whereas the microcrystalline wax forms irregular crystals that disrupt the overall wax crystal network. Young's modulus, elastic modulus and viscous modulus all decrease with increasing aqueous phase volume in the emulsions, although the slope of the decrease in elastic and viscous moduli is dependent on the addition of solid wax, as a result of strengthening the network. This work suggests the potential use for emulsions in lipstick applications, particularly when PGPR is used as an emulsifier, and with the addition of solid wax, as it increases network strength. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Comparative fine mapping of the Wax 1 (W1) locus in hexaploid wheat.

PubMed

Lu, Ping; Qin, Jinxia; Wang, Guoxin; Wang, Lili; Wang, Zhenzhong; Wu, Qiuhong; Xie, Jingzhong; Liang, Yong; Wang, Yong; Zhang, Deyun; Sun, Qixin; Liu, Zhiyong

2015-08-01

By applying comparative genomics analyses, a high-density genetic linkage map of the Wax 1 ( W1 ) locus was constructed as a framework for map-based cloning. Glaucousness is described as the scattering effect of visible light from wax deposited on the cuticle of plant aerial organs. In wheat, the wax on leaves and stems is mainly controlled by two sets of genes: glaucousness loci (W1 and W2) and non-glaucousness loci (Iw1 and Iw2). Bulked segregant analysis (BSA) and simple sequence repeat (SSR) mapping showed that Wax1 (W1) is located on chromosome arm 2BS between markers Xgwm210 and Xbarc35. By applying comparative genomics analyses, colinearity genomic regions of the W1 locus on wheat 2BS were identified in Brachypodium distachyon chromosome 5, rice chromosome 4 and sorghum chromosome 6, respectively. Four STS markers were developed using the Triticum aestivum cv. Chinese Spring 454 contig sequences and the International Wheat Genome Sequencing Consortium (IWGSC) survey sequences. W1 was mapped into a 0.93 cM genetic interval flanked by markers XWGGC3197 and XWGGC2484, which has synteny with genomic regions of 56.5 kb in Brachypodium, 390 kb in rice and 31.8 kb in sorghum. The fine genetic map can serve as a framework for chromosome landing, physical mapping and map-based cloning of the W1 in wheat.

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

NASA Astrophysics Data System (ADS)

Van Wambeke, F.; Pfreundt, U.; Barani, A.; Berthelot, H.; Moutin, T.; Rodier, M.; Hess, W. R.; Bonnet, S.

2015-12-01

N2 fixation fuels ~ 50 % of new primary production in the oligotrophic South Pacific Ocean. The VAHINE mesocosm experiment designed to track the fate of diazotroph derived nitrogen (DDN) in the New Caledonia lagoon. Here, we examined the temporal dynamics of heterotrophic bacterial production during this experiment. Three replicate large-volume (~ 50 m3) mesocosms were deployed and were intentionally fertilized with dissolved inorganic phosphorus (DIP) to stimulate N2 fixation. We specifically examined relationships between N2 fixation rates and primary production, determined bacterial growth efficiency and established carbon budgets of the system from the DIP fertilization to the end of the experiment (days 5-23). Heterotrophic bacterioplankton production (BP) and alkaline phosphatase activity (APA) were 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). 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 was notably higher than generally cited for oligotrophic environments (27-43 %), possibly due to a high representation of proteorhodopsin-containing organisms within the picoplanctonic community. The carbon budget showed that the main fate of gross primary production (particulate + dissolved) was 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 slightly correlated, and only during P2 phase, with N2 fixation rates. Our results suggest that most of the DDN reached the heterotrophic bacterial community through indirect processes, like mortality, lysis and grazing.

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

PubMed

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.

Valorization of lubricant-based wastewater for bacterial neutral lipids production: Growth-linked biosynthesis.

PubMed

Da Silva, Pedro D M P; Lima, Filipa; Alves, Maria Madalena; Bijmans, Martijn F M; Pereira, Maria Alcina

2016-09-15

Lipids produced by microorganisms are currently of great interest as raw material for either biofuels or oleochemicals production. Significant biosynthesis of neutral lipids, such as triacylglycerol (TAG) and wax esters (WE) are thought to be limited to a few strains. Hydrocarbonoclastic bacteria (HCB), key players in bioremediation of hydrocarbon contaminated ecosystems, are among this group of strains. Hydrocarbon rich wastewaters have been overlooked concerning their potential as raw material for microbial lipids production. In this study, lubricant-based wastewater was fed, as sole carbon source, to two HCB representative wild strains: Alcanivorax borkumensis SK2, and Rhodococcus opacus PD630. Neutral lipid production was observed with both strains cultivated under uncontrolled conditions of pH and dissolved oxygen. A. borkumensis SK2 was further investigated in a pH- and OD-controlled fermenter. Different phases were assessed separately in terms of lipids production and alkanes removal. The maximum TAG production rate occurred during stationary phase (4 mg-TAG/L h). The maximum production rate of WE-like compounds was 15 mg/L h, and was observed during exponential growth phase. Hydrocarbons removal was 97% of the gas chromatography (GC) resolved straight-chain alkanes. The maximum removal rate was observed during exponential growth phase (6 mg-alkanes/L h). This investigation proposes a novel approach for the management of lubricant waste oil, aiming at its conversion into valuable lipids. The feasibility of the concept is demonstrated under low salt (0.3%) and saline (3.3%) conditions, and presents clues for its technological development, since growth associated oil production opens the possibility for establishing continuous fermentation processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Long-chain (C19-C29) 1-chloro-n-alkanes in leaf waxes of halophytes of the Chenopodiaceae.

PubMed

Grossi, Vincent; Raphel, Danielle

2003-07-01

The hydrocarbon fraction of leaf waxes of three halophytes of the Chenopodiaceae common to Mediterranean salt marshes (Suaeda vera, Sarcocornia fruticosa and Halimione portulacoides) revealed the presence of a minor series of odd and even chains 1-chloro-n-alkanes ranging from C(19) to C(29). The identification of these new chlorinated plant constituents was based on a combination of mass spectrometry data with selective chlorine detection (CPG-AED) and was confirmed by comparison with authentic standards. The qualitative and quantitative distributions of these 1-chloro-n-alkanes varied inter-specifically. Homologues with an odd carbon-chain were predominant in all species but maximised at C(25) and C(27) in S. vera and S. fruticosa, and at C(27) and C(29) in H. portulacoides. Remarkably, 1-chloro-nonacosane was an abundant homologue only in this latter species. Leaves of S. vera contained 4 to 7 times more of total chloroalkanes than leaves of the other two species. These compounds accounted for 10, 4 and 1% of the hydrocarbon fraction of leaf waxes of S. vera, S. fruticosa and H. portulacoides, respectively. Attempts to link the occurrence of these chloroalkanes with other classes of leaf waxes (n-alkenes, n-aldehydes and n-alcohols) did not allowed a clear precursor-product relationship to be established. The biological functions as well as the mode of synthesis of alkylchlorides in (halophyte) plants remain unknown but undoubtedly deserve further attention.

Identification of bacterial contaminants from calcium carbonate filler production lines and an evaluation of biocide based decontamination procedures.

PubMed

Odić, Duško; Prah, Jana; Avguštin, Gorazd

2017-04-01

The aim of this study was to analyze the bacterial community in the production line of a calcium carbonate filler production company and to investigate possible causes for bacterial presence. Throughout 2012, 24 carbonate slurry and six groundwater samples were analyzed. Pseudomonas and Microbacterium were the most frequent contaminants in the slurry, whereas Pseudomonas and Brevundimonas dominated the groundwater samples. Of the 43 different bacterial strains isolated, only five were found both in the slurry and the groundwater, indicating that the latter was not a major source of contamination. The efficacy of 54 commercial biocidal formulations was tested against an artificial bacterial consortium composed of selected slurry isolates. A formulation containing 7.5-15% (v v -1 ) bronopol and 1.0-2.5% (v v -1 ) [chloroisothiazolinone (CIT) + methylisothiazolinone (MIT)] exhibited the highest efficacy. Of the possible causes for bacterial presence, sporogenesis and biocide adsorption to carbonate particles were found to be less probable compared to bacterial adsorption to particles, and the acquisition of resistance to biocides.

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed Central

Ji, Qianlong; Zhang, Kezhong; Yang, Mingfeng

2017-01-01

Cuticular waxes of plant and organ surfaces play an important role in protecting plants from biotic and abiotic stress and extending the freshness, storage time and shelf life in the post-harvest agricultural products. WRI1, a transcription factor of AP2/SHEN families, had been found to trigger the related genes taking part in the biosynthesis of seed oil in many plants. But whether WRI1 is involved in the biosynthesis of the cuticular waxes on the Malus fruits surface has been unclear. We investigated the changes of wax composition and structure, the related genes and WRI1 expression on Malus asiatica Nakai and sieversii fruits with the low temperature treatments, found that low temperature induced the up-regulated expression of McWRI1, which promoted gene expression of McKCS, McLACs and McWAX in very-long-chain fatty acid biosynthesis pathway, resulting in the accumulation of alkanes component and alteration of wax structure on the fruit surface. Corresponding results were verified in McWRI1 silenced by VIGS, and WRI1 silenced down-regulated the related genes on two kinds of fruits, it caused the diversity alteration in content of some alkanes, fatty acid and ester component in two kinds of fruits. We further conducted Y1H assay to find that McWRI1 transcription factor activated the promoter of McKCS, McLAC and McWAX to regulate their expression. These results demonstrated that McWRI1 is involved in regulating the genes related synthesis of very long chain fatty acid on surface of apple fruits in storage process, providing a highlight for improvement of the modified atmosphere storage of apple fruits. PMID:29073205

Mechanism for Tuning the Hydrophobicity of Microfibrillated Cellulose Films by Controlled Thermal Release of Encapsulated Wax

PubMed Central

Rastogi, Vibhore Kumar; Stanssens, Dirk; Samyn, Pieter

2014-01-01

Although films of microfibrillated cellulose (MFC) have good oxygen barrier properties due to its fine network structure, properties strongly deteriorate after absorption of water. In this work, a new approach has been followed for actively tuning the water resistance of a MFC fiber network by the inclusion of dispersed organic nanoparticles with encapsulated plant wax. The modified pulp suspensions have been casted into films and were subsequently cured at 40 to 220 °C. As such, static water contact angles can be specifically tuned from 120 to 150° by selection of the curing temperature in relation with the intrinsic transition temperatures of the modified pulp, as determined by thermal analysis. The appearance of encapsulated wax after curing was followed by a combination of morphological analysis, infrared spectroscopy and Raman mapping, showing balanced mechanisms of progressive release and migration of wax into the fiber network controlling the surface properties and water contact angles. Finally, the appearance of nanoparticles covered with a thin wax layer after complete thermal release provides highest hydrophobicity. PMID:28788241

A theoretical approach to evaluate the release rate of acetaminophen from erosive wax matrix dosage forms.

PubMed

Agata, Yasuyoshi; Iwao, Yasunori; Shiino, Kai; Miyagishima, Atsuo; Itai, Shigeru

2011-07-29

To predict drug dissolution and understand the mechanisms of drug release from wax matrix dosage forms containing glyceryl monostearate (GM; a wax base), aminoalkyl methacrylate copolymer E (AMCE; a pH-dependent functional polymer), and acetaminophen (APAP; a model drug), we tried to derive a novel mathematical model with respect to erosion and diffusion theory. Our model exhibited good agreement with the whole set of experimentally obtained values pertaining to APAP release at pH 4.0 and pH 6.5. In addition, this model revealed that the eroding speed of wax matrices was strongly influenced by the loading content of AMCE, but not that of APAP, and that the diffusion coefficient increased as APAP loading decreased and AMCE loading increased, thus directly defining the physicochemical properties of erosion and diffusion. Therefore, this model might prove a useful equation for the precise prediction of dissolution and for understanding the mechanisms of drug release from wax matrix dosage forms. Copyright © 2011 Elsevier B.V. All rights reserved.

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

PubMed

Park, Doo Hyun

2018-04-24

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

Carnauba wax p-methoxycinnamic diesters: Characterisation, antioxidant activity and simulated gastrointestinal digestion followed by in vitro bioaccessibility.

PubMed

Freitas, Claisa Andréa Silva; Vieira, Ícaro Gusmão Pinto; Sousa, Paulo Henrique Machado; Muniz, Celli Rodrigues; Gonzaga, Maria Leônia da Costa; Guedes, Maria Izabel Florindo

2016-04-01

The beneficial biological effects of cinnamic acid derivatives and the lack of studies on the antioxidant activity and bioavailability of cinnamic esters from carnauba wax, diesters were extracted from carnauba wax powder. Their structural, physical and morphological characteristics, antioxidant activity and in vitro bioaccessibility were measured. p-Methoxycinnamic diester (PCO-C) was identified, which has a crystalline, apolar structure and exhibited significant antioxidant activity (107.27 ± 3.92 μM Trolox/g of dry weight) before and after simulated in vitro gastrointestinal digestion and 32.46% bioaccessibility. In human cells, PCO-C (250 μg/mL) inhibited the production of intracellular reactive oxygen species, with an effect similar to that of Trolox (80 μM). Thermogravimetric analysis showed that PCO-C had high thermal stability and high UV absorption between 250 and 350 nm. These results indicate that this compound is promising as an antioxidant for pharmaceutical and food industry applications, such as the development of active packaging and functional foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Altitude effect on leaf wax carbon isotopic composition in humid tropical forests

NASA Astrophysics Data System (ADS)

Wu, Mong Sin; Feakins, Sarah J.; Martin, Roberta E.; Shenkin, Alexander; Bentley, Lisa Patrick; Blonder, Benjamin; Salinas, Norma; Asner, Gregory P.; Malhi, Yadvinder

2017-06-01

The carbon isotopic composition of plant leaf wax biomarkers is commonly used to reconstruct paleoenvironmental conditions. Adding to the limited calibration information available for modern tropical forests, we analyzed plant leaf and leaf wax carbon isotopic compositions in forest canopy trees across a highly biodiverse, 3.3 km elevation gradient on the eastern flank of the Andes Mountains. We sampled the dominant tree species and assessed their relative abundance in each tree community. In total, 405 sunlit canopy leaves were sampled across 129 species and nine forest plots along the elevation profile for bulk leaf and leaf wax n-alkane (C27-C33) concentration and carbon isotopic analyses (δ13C); a subset (76 individuals, 29 species, five forest plots) were additionally analyzed for n-alkanoic acid (C22-C32) concentrations and δ13C. δ13C values display trends of +0.87 ± 0.16‰ km-1 (95% CI, r2 = 0.96, p < 0.01) for bulk leaves and +1.45 ± 0.33‰ km-1 (95% CI, r2 = 0.94, p < 0.01) for C29n-alkane, the dominant chain length. These carbon isotopic gradients are defined in multi-species sample sets and corroborated in a widespread genus and several families, suggesting the biochemical response to environment is robust to taxonomic turnover. We calculate fractionations and compare to adiabatic gradients, environmental variables, leaf wax n-alkane concentrations, and sun/shade position to assess factors influencing foliar chemical response. For the 4 km forested elevation range of the Andes, 4-6‰ higher δ13C values are expected for upland versus lowland C3 plant bulk leaves and their n-alkyl lipids, and we expect this pattern to be a systematic feature of very wet tropical montane environments. This elevation dependency of δ13C values should inform interpretations of sedimentary archives, as 13C-enriched values may derive from C4 grasses, petrogenic inputs or upland C3 plants. Finally, we outline the potential for leaf wax carbon isotopes to trace biomarker

Soil water stress affects both cuticular wax content and cuticle-related gene expression in young saplings of maritime pine (Pinus pinaster Ait)

PubMed Central

2013-01-01

Background The cuticle is a hydrophobic barrier located at the aerial surface of all terrestrial plants. Recent studies performed on model plants, such as Arabidopsis thaliana, have suggested that the cuticle may be involved in drought stress adaptation, preventing non-stomatal water loss. Although forest trees will face more intense drought stresses (in duration and intensity) with global warming, very few studies on the role of the cuticle in drought stress adaptation in these long-lived organisms have been so far reported. Results This aspect was investigated in a conifer, maritime pine (Pinus pinaster Ait.), in a factorial design with two genetic units (two half-sib families with different growth rates) and two treatments (irrigated vs non-irrigated), in field conditions. Saplings were grown in an open-sided greenhouse and half were irrigated three times per week for two growing seasons. Needles were sampled three times per year for cuticular wax (composition and content) and transcriptome (of 11 genes involved in cuticle biosynthesis) analysis. Non-irrigated saplings (i) had a higher cuticular wax content than irrigated saplings and (ii) overexpressed most of the genes studied. Both these trends were more marked in the faster growing family. Conclusions The higher cuticular wax content observed in the non-irrigated treatment associated with strong modifications in products from the decarbonylation pathway suggest that cuticular wax may be involved in drought stress adaptation in maritime pine. This study provides also a set of promising candidate genes for future forward genetic studies in conifers. PMID:23815794

A Consistent and Predictable Commercial Broiler Chicken Bacterial Microbiota in Antibiotic-Free Production Displays Strong Correlations with Performance.

PubMed

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

2018-06-15

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

Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating

PubMed Central

Said, Asmaa; Salah, Abeer; Abdel Fattah, Gamal

2017-01-01

Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin’s rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications. PMID:28772884

Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating.

PubMed

Said, Asmaa; Salah, Abeer; Fattah, Gamal Abdel

2017-05-12

Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin's rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications.

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

PubMed

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

2012-11-07

To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests. This transversal study included 85 children residing in a slum and 43 children from a private school, all aged between 6 and 10 years, in Osasco, Brazil. For characterization of the groups, data regarding the socioeconomic status and basic housing sanitary conditions were collected. Anthropometric data was obtained in children from both groups. All children completed the hydrogen (H(2)) and methane (CH(4)) breath test in order to assess small intestinal bacterial overgrowth (SIBO). SIBO was diagnosed when there was an increase in H(2) ≥ 20 ppm or CH(4) ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion. Children from the slum group had worse living conditions and lower nutritional indices than children from the private school. SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P = 0.0007). Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P = 0.007). A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO. Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001). Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum. Colonic production of hydrogen was lower in methane-producing children (P = 0.017). Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production. Hydrogen is a substrate for methane production in the colon.

Role of water-soluble polysaccharides in bacterial cellulose production.

PubMed

Ishida, Takehiko; Mitarai, Makoto; Sugano, Yasushi; Shoda, Makoto

2003-08-20

Acetobacter xylinum BPR2001 produces water-insoluble bacterial cellulose (BC) and a water-soluble polysaccharide called acetan in corn steep liquor-fructose medium. Acetobacter xylinum EP1, which is incapable of acetan production was derived by disrupting the aceA gene of BPR2001. The BC production by EP1 (2.88 g/L) was lower than that by BPR2001 (4.6 g/L) in baffled-flask culture. When purified acetan or agar was added to the medium from the start of cultivation, the BC production by EP1 was enhanced and the final BC yield of EP1 was almost the same as that of BPR2001. A similar improvement of BC production by EP1 by the addition of agar was also confirmed by cultivation in a 50-L airlift reactor. From these results, the role of acetan in BC production is associated with the increase in the viscosity of the culture medium which may hinder coagulation of BC and cells in the culture, thereby accelerating the growth of BPR2001 and BC production by BPR2001. Copyright 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 474-478, 2003.

Organogel as a replacement of saturated fat in food products

USDA-ARS?s Scientific Manuscript database

Organogels of edible oil have drawn a great interest as promising alternatives to saturated fats and trans fats. Plant waxes are recognized as promising organogelators, which can provide organogels from healthful vegetable oils at low concentrations. Plant waxes are obtained as by-products during th...

Cuticular permeance in relation to wax and cutin development along the growing barley (Hordeum vulgare) leaf.

PubMed

Richardson, Andrew; Wojciechowski, Tobias; Franke, Rochus; Schreiber, Lukas; Kerstiens, Gerhard; Jarvis, Mike; Fricke, Wieland

2007-05-01

The developing leaf three of barley provides an excellent model system for the direct determination of relationships between amounts of waxes and cutin and cuticular permeance. Permeance of the cuticle was assessed via the time-course of uptake of either toluidine blue or (14)C-labelled benzoic acid ([(14)C] BA) along the length of the developing leaf. Toluidine blue uptake only occurred within the region 0-25 mm from the point of leaf insertion (POLI). Resistance--the inverse of permeance--to uptake of [(14)C] BA was determined for four leaf regions and was lowest in the region 10-20 mm above POLI. At 20-30 and 50-60 mm above POLI, it increased by factors of 6 and a further 32, respectively. Above the point of emergence of leaf three from the sheath of leaf two, which was 76-80 mm above POLI, resistance was as high as at 50-60 mm above POLI. GC-FID/MS analyses of wax and cutin showed that: (1) the initial seven fold increase in cuticular resistance coincided with increase in cutin coverage and appearance of waxes; (2) the second, larger and final increase in cuticle resistance was accompanied by an increase in wax coverage, whereas cutin coverage remained unchanged; (3) cutin deposition in barley leaf epidermis occurred in parallel with cell elongation, whereas deposition of significant amounts of wax commenced as cells ceased to elongate.

Impact of bacterial DMS production on [DMS/P] under ocean acidification (KOSMOS_2.0): insights from the subtropics.

NASA Astrophysics Data System (ADS)

Suffrian, K.; Posman, K.; Matrai, P.; Countway, P. D.; Archer, S. D.

2016-02-01

Marine dimethyl sulfide (DMS), a ubiquitous atmospheric trace gas, comprises the largest source of sulphur to the atmosphere. So far, temperate and high-latitude ocean acidification (OA) mesocosm experiments point to a decrease of this precursor for cloud condensation nuclei, leading to fewer clouds, and resulting in an increased radiative force. To our knowledge no experiments have yet been carried out which address multiple forcings (temperature and pCO2) in the subtropics. We thus joined the 55-day KOSMOS large mesocosm experiment on Gran Canaria to investigate if the observed decrease could be global. As subtropical and tropical oceans comprise a large proportion of the world's oceans, we were i.a. interested if 1) increasing ocean acidification in a subtropical environment would also decrease [DMS], and if 2) bacterial DMS production could explain a large part of potential decreases. Here we focus on the first phase (day 1-23), showing the impact of OA on [DMS] and [DMSP] (dimethylsulfoniopropionate). Bacteria are thought to be the main DMS producers, so we used 35S-DMSP as a tracer to investigate the impact of bacterial DMS production on observed [DMS] decreases correlated with increasing OA. [DMS] showed a strong inverse correlation with [H+] (-50% vs. ambient control). [DMSPp] (-37%) and [DMSPd] (-20%) also decreased with increasing [H+]. Our results support findings from higher latitude mesocosm experiments, thus suggesting the effect might be global. Bacterial DMS production rates, their rate constants, and yields during the peak in [DMS] were negatively correlated with [H+] on single days, while gross DMS-production was high enough to support observed [DMS] increases. Bacterial DMSP uptake rates and DMS production rates were not correlated with [H+] on any other day. Bacterial effects alone are thus not enough to explain observed changes in standing stocks. We will further explore the results by normalizing to bacterial protein production, cell abundance

Studies on Batch Production of Bacterial Concentrates from Mixed Species Lactic Starters

PubMed Central

Pettersson, H. E.

1975-01-01

Optimum growth conditions for mixed species starter FDs 0172 at constant pH in skim milk, whey, and tryptone medium were investigated. Growth rate and maximum population were optimal at 30 C. pH values between 5.5 and 7.0 did not influence the growth rate and maximum population obtainable. Lactic acid-producing activity declined rapidly after reaching the end of the exponential growth phase. The bacterial balance was found to be influenced by the growth parameters: media, pH, temperature, and neutralizer. Skim milk or whey medium at 25 C, pH 6.5, and neutralized with 20% (vol/vol) NH4OH kept the bacterial balance almost constant throughout the cultivation. Grown in tryptone medium at constant pH, the changes in bacterial balance and other metabolic activities were striking compared to the other two media tested. The effect of lactate as an inhibitor was found to be complex, changing with the growth conditions. Concentrates made from mixed species starters FDs 0172, FD 0570, CH 0170, CHs 0170, and T 27 were comparable to controls when cultivated at the optimum conditions found and thereafter centrifuged. Aroma production, proteolytic activity, and CO2 production did not change significantly compared to controls when cultivated at optimum conditions in skim milk or whey medium. PMID:16350009

Galleria mellonella (greater wax moth) larvae as a model for antibiotic susceptibility testing and acute toxicity trials.

PubMed

Ignasiak, Katarzyna; Maxwell, Anthony

2017-08-29

Infectivity trials and toxicity testing in rodents are important prerequisites to the use of compounds in man. However, trials in rats and mice are expensive and there are ethical considerations. Galleria mellonella (greater wax moth) larvae are a potential alternative. We have assessed the use of these insects in infectivity trials and toxicity testing. Using four bacterial species (two Gram-negative and two Gram-positive) we have assessed the efficacy of four antibiotics against infections in Galleria and compared the antibiotic susceptibility with that in humans. In general, we find a good correlation. Similarly, we have assessed 11 compounds (initially tested blind) for their toxicity in Galleria and compared this with toxicity trials in mice and rats. Again we found a good correlation between toxicity in Galleria and that in rodents. We have found, in our hands, that G. mellonella larvae can be used in infectivity trials and toxicity testing, and that these assays represent an inexpensive and readily executable alternative to testing in rodents.

Bacterial antisense RNAs are mainly the product of transcriptional noise.

PubMed

Lloréns-Rico, Verónica; Cano, Jaime; Kamminga, Tjerko; Gil, Rosario; Latorre, Amparo; Chen, Wei-Hua; Bork, Peer; Glass, John I; Serrano, Luis; Lluch-Senar, Maria

2016-03-01

cis-Encoded antisense RNAs (asRNAs) are widespread along bacterial transcriptomes. However, the role of most of these RNAs remains unknown, and there is an ongoing discussion as to what extent these transcripts are the result of transcriptional noise. We show, by comparative transcriptomics of 20 bacterial species and one chloroplast, that the number of asRNAs is exponentially dependent on the genomic AT content and that expression of asRNA at low levels exerts little impact in terms of energy consumption. A transcription model simulating mRNA and asRNA production indicates that the asRNA regulatory effect is only observed above certain expression thresholds, substantially higher than physiological transcript levels. These predictions were verified experimentally by overexpressing nine different asRNAs in Mycoplasma pneumoniae. Our results suggest that most of the antisense transcripts found in bacteria are the consequence of transcriptional noise, arising at spurious promoters throughout the genome.

Bioaugmentation of Hydrogenispora ethanolica LX-B affects hydrogen production through altering indigenous bacterial community structure.

PubMed

Yang, Zhiman; Guo, Rongbo; Shi, Xiaoshuang; He, Shuai; Wang, Lin; Dai, Meng; Qiu, Yanling; Dang, Xiaoxiao

2016-07-01

Bioaugmentation can facilitate hydrogen production from complex organic substrates, but it still is unknown how indigenous microbial communities respond to the added bacteria. Here, using a Hydrogenispora ethanolica LX-B (named as LX-B) bioaugmentation experiments, the distribution of metabolites and the responses of indigenous bacterial communities were investigated via batch cultivation (BC) and repeated batch cultivation (RBC). In BC the LX-B/sludge ratio of 0.12 achieved substantial high hydrogen yield, which was over twice that of control. In RBC one-time bioaugmentation and repeated batch bioaugmentation of LX-B resulted in the hydrogen yield that was average 1.2-fold and 0.8-fold higher than that in control, respectively. This improved hydrogen production performance mainly benefited from a shift in composition of the indigenous bacterial community caused by LX-B bioaugmentation. The findings represented an important step in understanding the relationship between bioaugmentation, a shift in bacterial communities, and altered bioreactor performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Two Predicted Transmembrane Domains Exclude Very Long Chain Fatty acyl-CoAs from the Active Site of Mouse Wax Synthase

PubMed Central

Kawelke, Steffen; Feussner, Ivo

2015-01-01

Wax esters are used as coatings or storage lipids in all kingdoms of life. They are synthesized from a fatty alcohol and an acyl-CoA by wax synthases. In order to get insights into the structure-function relationships of a wax synthase from Mus musculus, a domain swap experiment between the mouse acyl-CoA:wax alcohol acyltransferase (AWAT2) and the homologous mouse acyl-CoA:diacylglycerol O-acyltransferase 2 (DGAT2) was performed. This showed that the substrate specificity of AWAT2 is partially determined by two predicted transmembrane domains near the amino terminus of AWAT2. Upon exchange of the two domains for the respective part of DGAT2, the resulting chimeric enzyme was capable of incorporating up to 20% of very long acyl chains in the wax esters upon expression in S. cerevisiae strain H1246. The amount of very long acyl chains in wax esters synthesized by wild type AWAT2 was negligible. The effect was narrowed down to a single amino acid position within one of the predicted membrane domains, the AWAT2 N36R variant. Taken together, we provide first evidence that two predicted transmembrane domains in AWAT2 are involved in determining its acyl chain length specificity. PMID:26714272

Three Dimensional Morphodynamic and Vegetation Modeling of Wax Lake Delta

NASA Astrophysics Data System (ADS)

Khadka, A. K.; Meselhe, E. A.; Sadid, K. M.

2013-12-01

The Wax Lake Delta (WLD) is located at the downstream end of the Wax Lake outlet, approximately 13 miles upstream from Morgan City, Louisiana. In 1942 the United States Army Corps of Engineer (USACE) dredged Wax Lake Outlet channel from lower Atchafalaya River to reduce flood stages at Morgan City. The channel diverts 50% of Atchafalaya River water and sediment to WLD. Since 1942, the WLD has been building seaward due to the deposition of sediment at the channel mouth. Growth of this delta supports the concept of land building via river diversions. A process based morphodynamic model (Delft3D) with the ability to predict evolution of river-dominated deltas is used in this study to further our understanding of land-building and delta growth processes. Initial model bathymetry is prepared based on USACE hydrographic survey of 1998 along with LIDAR survey data for over bank areas. Two continuous gauges at Wax Lake outlet near Calumet and Atchafalaya Bay near Eugene Island are used to assign upstream inflow and outflow boundary conditions, respectively. The model is calibrated and validated for Hydrodynamics and Sediment transport through two sets of field observations for flooded and average conditions. Vertical velocity and suspended sediment profiles made in the channels of the WLD in 2000 and 2001 are used for the model calibration and validation. More comprehensive field observations are being gathered as part of an ongoing study funded by the National Science Foundation (FESD-Delta Dynamics Collaboratory). Data include mutli-beam bathymetric data, velocities, sediment, and nutrient concentrations in the channels as well as on top of the islands. The Delft3D morphodynamic model for WLD provides quantitative information regarding water and sediment distribution among the inter-connected channel bifurcations, the exchange of sediment and nutrients between the channels and islands. The model is being used to investigate the rate of land building and delta growth from

Bacterial overgrowth and methane production in children with encopresis.

PubMed

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

2010-05-01

To assess the prevalence of small intestinal bacterial overgrowth (SIBO) and methane production in children with encopresis. Radiographic fecal impaction (FI) scores were assessed in children with secondary, retentive encopresis and compared with the breath test results. Breath tests with hypoosmotic lactulose solution were performed in both the study patients (n = 50) and gastrointestinal control subjects (n = 39) groups. The FI scores were significantly higher in the patients with encopresis who were methane producers (P < .01). SIBO was diagnosed in 21 of 50 (42%) patients with encopresis and 9 of 39 (23%) of control subjects (P = .06). Methane was produced in 56% of the patients with encopresis versus 23.1% of the control subjects in the gastrointestinal group (P < .01). Fasting methane level was elevated in 48% versus 10.3 %, respectively (P < .01). Children with FI and encopresis had a higher prevalence of SIBO, elevated basal methane levels, and higher methane production. Methane production was associated with more severe colonic impaction. Further study is needed to determine whether methane production is a primary or secondary factor in the pathogenesis of SIBO and encopresis.

Conversion of post consumer polyethylene to the biodegradable polymer polyhydroxyalkanoate.

PubMed

Guzik, Maciej W; Kenny, Shane T; Duane, Gearoid F; Casey, Eoin; Woods, Trevor; Babu, Ramesh P; Nikodinovic-Runic, Jasmina; Murray, Michael; O'Connor, Kevin E

2014-05-01

A process for the conversion of post consumer (agricultural) polyethylene (PE) waste to the biodegradable polymer medium chain length polyhydroxyalkanoate (mcl-PHA) is reported here. The thermal treatment of PE in the absence of air (pyrolysis) generated a complex mixture of low molecular weight paraffins with carbon chain lengths from C8 to C32 (PE pyrolysis wax). Several bacterial strains were able to grow and produce PHA from this PE pyrolysis wax. The addition of biosurfactant (rhamnolipids) allowed for greater bacterial growth and PHA accumulation of the tested strains. Some strains were only capable of growth and PHA accumulation in the presence of the biosurfactant. Pseudomonas aeruginosa PAO-1 accumulated the highest level of PHA with almost 25 % of the cell dry weight as PHA when supplied with the PE pyrolysis wax in the presence of rhamnolipids. The change of nitrogen source from ammonium chloride to ammonium nitrate resulted in faster bacterial growth and the earlier onset of PHA accumulation. To our knowledge, this is the first report where PE is used as a starting material for production of a biodegradable polymer.

Heritability of the structures and 13C fractionation in tomato leaf wax alkanes: a genetic model system to inform paleoenvironmental reconstructions

NASA Astrophysics Data System (ADS)

Bender, Amanda L. D.; Chitwood, Daniel H.; Bradley, Alexander S.

2017-06-01

Leaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of n-alkanes as a paleoenvironmental proxy may be modulated by the extent to which biological as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is usually an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2H of waxes via rainwater and the δ13C of leaf waxes by changing plant communities. We measured the degree of genetic control over δ13C variation in leaf waxes within closely related species with an experimental greenhouse growth study. We measured the proportion of variability in structural and isotopic leaf wax traits that is attributable to genetic variation using a set of 76 introgression lines (ILs) between two interfertile Solanum (tomato) species: S. lycopersicum cv M82 (hereafter cv M82) and S. pennellii. Leaves of S. pennellii, a wild desert tomato relative, produced significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions. We report a methylation index to summarize the ratio of branched (iso- and anteiso-) to total alkanes. Between S. pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2-1.4‰ over n-alkanes. The broad-sense heritability values (H2) of leaf wax traits describe the degree to which genetic variation contributes to variation of these traits. Variation of individual carbon isotopic compositions of alkanes were of low heritability (H2 = 0.13-0.19), suggesting that most variation in δ13C of leaf waxes in this study can be attributed to environmental variance. This supports the interpretation that variation in the δ13C of wax compounds recorded in sediments reflects

Establishing very long-chain fatty alcohol and wax ester biosynthesis in Saccharomyces cerevisiae.

PubMed

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.

Statistical analysis of the photodegradation of imazethapyr on the surface of extracted soybean (Glycine max) and corn (Zea mays) epicuticular waxes.

PubMed

Anderson, Scott C; Christiansen, Amy; Peterson, Alexa; Beukelman, Logan; Nienow, Amanda M

2016-10-12

The photodegradation rate of the herbicide imazethapyr on epicuticular waxes of soybean and corn plants was investigated. Plant age, relative humidity, temperature, and number of light banks were varied during plant growth, analyzed statistically, and examined to determine if these factors had an effect on the photodegradation of imazethapyr. Through ultraviolet/visible (UV-Vis) and fluorescence spectroscopy, epicuticular wax characteristics of soybean and corn plants were explored, were used to confirm observations determined statistically, and explain correlations between the rate constants and the composition of the epicuticular waxes. Plant age, the interaction between plant age and light, and the quadratic dependence on temperature were all determined to have a significant impact on the photodegradation rate of imazethapyr on the epicuticular waxes of soybean plants. As for the photodegradation rate on the epicuticular waxes of corn plants, the number of light banks used during growing and temperature were significant factors.

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

PubMed

Fischer, H; Pusch, M

1999-10-01

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

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

PubMed Central

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

Cooling of High-Power LED Lamp Using a Commercial Paraffin Wax

NASA Astrophysics Data System (ADS)

Zmywaczyk, J.; Zbińkowski, P.; Smogór, H.; Olejnik, A.; Koniorczyk, P.

2017-03-01

Commercial paraffin wax used by Bolsius Nederland B.V. for manufacturing various kinds of candles was applied as a phase-change material (PCM) for cooling a 28 W high-power light emitting diode (LED) panel during its operation. The main problem arising during operation of an LED is thermal management. According to the manufacturer's datasheet specifications (BioSolution Ltd. www.biosolution.pl, the operating temperature range for the LED street lamp UL28W is (-30 {°}C) to (+40 {°}C). The object of the present study was an LED panel containing 28 pieces of high-power 1W LEDs connected in series (4 LEDs in each of the 7 rows) mounted on an aluminum plate of dimensions 80 mm by 135 mm. The tested aluminum plate was placed in a block made of aluminum with a hollow compartment containing Bolsius paraffin wax of density 914 kg\\cdot m^{-3} at room temperature. Temperatures were recorded using K-type thermocouples at selected locations of the tested LED panel for several values of the power supplied to it, while utilizing PCM and without it. As the manufacturer of Bolsius wax candles does not provide any data on the thermal properties of the material used, it was necessary to carry out micro-calorimetric research. Thermophysical properties of the paraffin wax such as the apparent specific heat, enthalpy of phase transition and temperature of phase change transition during heating and cooling were determined using the Netzsch DSC 214 Polyma. The Netzsch TG 209F3 Tarsus was used for TG/DTG measurements. DSC investigations revealed the following thermal transitions taking place during the first heating: solid-solid transition (onset 30.4 {°}C, peak at 40.9 {°}C), solid-liquid transition (onset 47.7 {°}C, peak at 54.9 {°}C, end at 58.3 {°}C), latent heat of energy storage 201 J\\cdot g^{-1}, apparent specific heat corresponding to peak at 41.5 {°}C (5.498 J\\cdot g^{-1}\\cdot K^{-1}). DTG investigations revealed that the decomposition of paraffin wax is a two

Overexpression of the Novel Arabidopsis Gene At5g02890 Alters Inflorescence Stem Wax Composition and Affects Phytohormone Homeostasis

PubMed Central

Xu, Liping; Zeisler, Viktoria; Schreiber, Lukas; Gao, Jie; Hu, Kaining; Wen, Jing; Yi, Bin; Shen, Jinxiong; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong

2017-01-01

The cuticle is composed of cutin and cuticular wax. It covers the surfaces of land plants and protects them against environmental damage. At5g02890 encodes a novel protein in Arabidopsis thaliana. In the current study, protein sequence analysis showed that At5g02890 is highly conserved in the Brassicaceae. Arabidopsis lines overexpressing At5g02890 (OE-At5g02890 lines) and an At5g02890 orthologous gene from Brassica napus (OE-Bn1 lines) exhibited glossy stems. Chemical analysis revealed that overexpression of At5g02890 caused significant reductions in the levels of wax components longer than 28 carbons (C28) in inflorescence stems, whereas the levels of wax molecules of chain length C28 or shorter were significantly increased. Transcriptome analysis indicated that nine of 11 cuticular wax synthesis-related genes with different expression levels in OE-At5g02890 plants are involved in very-long-chain fatty acid (VLCFA) elongation. At5g02890 is localized to the endoplasmic reticulum (ER), which is consistent with its function in cuticular wax biosynthesis. These results demonstrate that the overexpression of At5g02890 alters cuticular wax composition by partially blocking VLCFA elongation of C28 and higher. In addition, detailed analysis of differentially expressed genes associated with plant hormones and endogenous phytohormone levels in wild-type and OE-At5g02890 plants indicated that abscisic acid (ABA), jasmonic acid (JA), and jasmonoyl-isoleucine (JA-Ile) biosynthesis, as well as polar auxin transport, were also affected by overexpression of At5g02890. Taken together, these findings indicate that overexpression of At5g02890 affects both cuticular wax biosynthesis and phytohormone homeostasis in Arabidopsis. PMID:28184233

Multiple plant-wax compounds record differential sources and ecosystem structure in large river catchments

NASA Astrophysics Data System (ADS)

Hemingway, Jordon D.; Schefuß, Enno; Dinga, Bienvenu Jean; Pryer, Helena; Galy, Valier V.

2016-07-01

The concentrations, distributions, and stable carbon isotopes (δ13C) of plant waxes carried by fluvial suspended sediments contain valuable information about terrestrial ecosystem characteristics. To properly interpret past changes recorded in sedimentary archives it is crucial to understand the sources and variability of exported plant waxes in modern systems on seasonal to inter-annual timescales. To determine such variability, we present concentrations and δ13C compositions of three compound classes (n-alkanes, n-alcohols, n-alkanoic acids) in a 34-month time series of suspended sediments from the outflow of the Congo River. We show that exported plant-dominated n-alkanes (C25-C35) represent a mixture of C3 and C4 end members, each with distinct molecular distributions, as evidenced by an 8.1 ± 0.7‰ (±1σ standard deviation) spread in δ13C values across chain-lengths, and weak correlations between individual homologue concentrations (r = 0.52-0.94). In contrast, plant-dominated n-alcohols (C26-C36) and n-alkanoic acids (C26-C36) exhibit stronger positive correlations (r = 0.70-0.99) between homologue concentrations and depleted δ13C values (individual homologues average ⩽-31.3‰ and -30.8‰, respectively), with lower δ13C variability across chain-lengths (2.6 ± 0.6‰ and 2.0 ± 1.1‰, respectively). All individual plant-wax lipids show little temporal δ13C variability throughout the time-series (1σ ⩽ 0.9‰), indicating that their stable carbon isotopes are not a sensitive tracer for temporal changes in plant-wax source in the Congo basin on seasonal to inter-annual timescales. Carbon-normalized concentrations and relative abundances of n-alcohols (19-58% of total plant-wax lipids) and n-alkanoic acids (26-76%) respond rapidly to seasonal changes in runoff, indicating that they are mostly derived from a recently entrained local source. In contrast, a lack of correlation with discharge and low, stable relative abundances (5-16%) indicate that

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

PubMed

Wu, Jyh-Ming; Liu, Ren-Han

2012-09-01

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

Water Activated Graphene Oxide Transfer Using Wax Printed Membranes for Fast Patterning of a Touch Sensitive Device.

PubMed

Baptista-Pires, Luis; Mayorga-Martínez, Carmen C; Medina-Sánchez, Mariana; Montón, Helena; Merkoçi, Arben

2016-01-26

We demonstrate a graphene oxide printing technology using wax printed membranes for the fast patterning and water activation transfer using pressure based mechanisms. The wax printed membranes have 50 μm resolution, longtime stability and infinite shaping capability. The use of these membranes complemented with the vacuum filtration of graphene oxide provides the control over the thickness. Our demonstration provides a solvent free methodology for printing graphene oxide devices in all shapes and all substrates using the roll-to-roll automatized mechanism present in the wax printing machine. Graphene oxide was transferred over a wide variety of substrates as textile or PET in between others. Finally, we developed a touch switch sensing device integrated in a LED electronic circuit.

Bacterial antisense RNAs are mainly the product of transcriptional noise

PubMed Central

Lloréns-Rico, Verónica; Cano, Jaime; Kamminga, Tjerko; Gil, Rosario; Latorre, Amparo; Chen, Wei-Hua; Bork, Peer; Glass, John I.; Serrano, Luis; Lluch-Senar, Maria

2016-01-01

cis-Encoded antisense RNAs (asRNAs) are widespread along bacterial transcriptomes. However, the role of most of these RNAs remains unknown, and there is an ongoing discussion as to what extent these transcripts are the result of transcriptional noise. We show, by comparative transcriptomics of 20 bacterial species and one chloroplast, that the number of asRNAs is exponentially dependent on the genomic AT content and that expression of asRNA at low levels exerts little impact in terms of energy consumption. A transcription model simulating mRNA and asRNA production indicates that the asRNA regulatory effect is only observed above certain expression thresholds, substantially higher than physiological transcript levels. These predictions were verified experimentally by overexpressing nine different asRNAs in Mycoplasma pneumoniae. Our results suggest that most of the antisense transcripts found in bacteria are the consequence of transcriptional noise, arising at spurious promoters throughout the genome. PMID:26973873

In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax-decyl oleate nanoparticles.

PubMed

Villalobos-Hernández, J R; Müller-Goymann, C C

2007-01-01

This paper describes the in vitro photoprotection in the UV-A range, i.e. 320-400 nm obtained by the use of carnauba wax-decyl oleate nanoparticles either as encapsulation systems or as accompanying vehicles for inorganic sunscreens such as barium sulfate, strontium carbonate and titanium dioxide. Lipid-free inorganic sunscreen nanosuspensions, inorganic sunscreen-free wax-oil nanoparticle suspensions and wax-oil nanoparticle suspensions containing inorganic sunscreens dispersed either in their oil phase or their aqueous phase were prepared by high pressure homogenization. The in vitro erythemal UV-A protection factors (EUV-A PFs) of the nanosuspensions were calculated by means of a sun protection analyzer. EUV-A PFs being no higher than 4 were obtained by the encapsulation of barium sulfate and strontium carbonate, meanwhile by the distribution of titanium dioxide in presence of wax-oil nanoparticles, the EUV-A PFs varied between 2 and 19. The increase in the EUV-A PFs of the titanium dioxide obtained by the use of wax-oil nanoparticles demonstrated a better performance of the sun protection properties of this pigment in the UV-A region.

Late Quaternary environmental change in the interior South American tropics: new insight from leaf wax stable isotopes

NASA Astrophysics Data System (ADS)

Fornace, Kyrstin L.; Whitney, Bronwen S.; Galy, Valier; Hughen, Konrad A.; Mayle, Francis E.

2016-03-01

Stable isotope analysis of leaf waxes in a sediment core from Laguna La Gaiba, a shallow lake located at the Bolivian margin of the Pantanal wetlands, provides new perspective on vegetation and climate change in the lowland interior tropics of South America over the past 40,000 years. The carbon isotopic compositions (δ13C) of long-chain n-alkanes reveal large shifts between C3- and C4-dominated vegetation communities since the last glacial period, consistent with landscape reconstructions generated with pollen data from the same sediment core. Leaf wax δ13C values during the last glacial period reflect an open landscape composed of C4 grasses and C3 herbs from 41-20 ka. A peak in C4 abundance during the Last Glacial Maximum (LGM, ∼21 ka) suggests drier or more seasonal conditions relative to the earlier glacial period, while the development of a C3-dominated forest community after 20 ka points to increased humidity during the last deglaciation. Within the Holocene, large changes in the abundance of C4 vegetation indicate a transition from drier or more seasonal conditions during the early/mid-Holocene to wetter conditions in the late Holocene coincident with increasing austral summer insolation. Strong negative correlations between leaf wax δ13C and δD values over the entire record indicate that the majority of variability in leaf wax δD at this site can be explained by variability in the magnitude of biosynthetic fractionation by different vegetation types rather than changes in meteoric water δD signatures. However, positive δD deviations from the observed δ13C- δD trends are consistent with more enriched source water and drier or more seasonal conditions during the early/mid-Holocene and LGM. Overall, our record adds to evidence of varying influence of glacial boundary conditions and orbital forcing on South American Summer Monsoon precipitation in different regions of the South American tropics. Moreover, the relationships between leaf wax stable

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

NASA Astrophysics Data System (ADS)

Sherr, Barry F.; Sherr, Evelyn B.

2003-04-01

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

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

PubMed

Römling, Ute; Galperin, Michael Y

2015-09-01

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 (i) the expression of the biosynthesis apparatus, (ii) the export of the nascent β-D-glucan polymer to the cell surface, and (iii) the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of resulting biofilms, which is particularly important for the interactions of bacteria with higher organisms - leading to rhizosphere colonization and modulating the virulence of cellulose-producing bacterial pathogens inside and outside of host cells. We review the organization of four principal types of cellulose synthase operon found in various bacterial genomes, identify additional bcs genes that encode 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 and in the choice between acute infection and persistence in the host. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

Waxing Gibbous

NASA Image and Video Library

2017-12-08

Waxing gibbous. Visible to the southeast in early evening, up for most of the night. This marks the first time that accurate shadows at this level of detail are possible in such a computer simulation. The shadows are based on the global elevation map being developed from measurements by the Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO). LOLA has already taken more than 10 times as many elevation measurements as all previous missions combined. The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 12 seconds, as it is in this animation, our changing view of the Moon makes it look like it's wobbling. This wobble is called libration. The word comes from the Latin for "balance scale" (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon's disk and the location on the Moon where the Earth is directly overhead. The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon's north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by more than 10%. The most noticed monthly variation in the Moon's appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and

Waxing crescent

NASA Image and Video Library

2017-12-08

Waxing crescent. Visible toward the southwest in early evening. This marks the first time that accurate shadows at this level of detail are possible in such a computer simulation. The shadows are based on the global elevation map being developed from measurements by the Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO). LOLA has already taken more than 10 times as many elevation measurements as all previous missions combined. The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 12 seconds, as it is in this animation, our changing view of the Moon makes it look like it's wobbling. This wobble is called libration. The word comes from the Latin for "balance scale" (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon's disk and the location on the Moon where the Earth is directly overhead. The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon's north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by more than 10%. The most noticed monthly variation in the Moon's appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and is high in the sky at

Surfactant-free carnauba wax dispersion and its use for layer-by-layer assembled protective surface coatings on wood

NASA Astrophysics Data System (ADS)

Lozhechnikova, Alina; Bellanger, Hervé; Michen, Benjamin; Burgert, Ingo; Österberg, Monika

2017-02-01

Protection from liquid water and UV radiation are equally important, and a sophisticated approach is needed when developing surface coatings that preserve the natural and well-appreciated aesthetic appearance of wood. In order to prevent degradation and prolong the service life of timber, a protective coating was assembled using carnauba wax particles and zinc oxide nanoparticles via layer-by-layer deposition in water. For this purpose, a facile sonication route was developed to produce aqueous wax dispersion without any surfactants or stabilizers. The suspension was stable above pH 4 due to the electrostatic repulsion between the negatively charged wax particles. The particle size could be controlled by the initial wax concentration with average particle sizes ranging from 260 to 360 nm for 1 and 10 g/L, respectively. The deposition of wax particles onto the surface of spruce wood introduced additional roughness to the wood surface at micron level, while zinc oxide provided nano roughness and UV-absorbing properties. In addition to making wood superhydrophobic, this novel multilayer coating enhanced the natural moisture buffering capability of spruce. Moreover, wood surfaces prepared in this fashion showed a significant reduction in color change after exposure to UV light. A degradation of the wax through photocatalytic activity of the ZnO particles was measured by FTIR, indicating that further studies are required to achieve long-term stability. Nevertheless, the developed coating showed a unique combination of superhydrophobicity and excellent moisture buffering ability and some UV protection, all achieved using an environmentally friendly coating process, which is beneficial to retain the natural appearance of wood and improve indoor air quality and comfort.

Wax and cutin mutants of Arabidopsis: Quantitative characterization of the cuticular transport barrier in relation to chemical composition.

PubMed

Sadler, Christina; Schroll, Bettina; Zeisler, Viktoria; Waßmann, Friedrich; Franke, Rochus; Schreiber, Lukas

2016-09-01

Using (14)C-labeled epoxiconazole as a tracer, cuticular permeability of Arabidopsis thaliana leaves was quantitatively measured in order to compare different wax and cutin mutants (wax2, cut1, cer5, att1, bdg, shn3 and shn1) to the corresponding wild types (Col-0 and Ws). Mutants were characterized by decreases or increases in wax and/or cutin amounts. Permeances [ms(-1)] of Arabidopsis cuticles either increased in the mutants compared to wild type or were not affected. Thus, genetic changes in wax and cutin biosynthesis in some of the investigated Arabidopsis mutants obviously impaired the coordinated cutin and wax deposition at the outer leaf epidermal cell wall. As a consequence, barrier properties of cuticles were significantly decreased. However, increasing cutin and wax amounts by genetic modifications, did not automatically lead to improved cuticular barrier properties. As an alternative approach to the radioactive transport assay, changes in chlorophyll fluorescence were monitored after foliar application of metribuzine, an herbicide inhibiting electron transport in chloroplasts. Since both, half-times of photosynthesis inhibition as well as times of complete inhibition, in fact correlated with (14)C-epoxiconazole permeances, different rates of decline of photosynthetic yield between mutants and wild type must be a function of foliar uptake of the herbicide across the cuticle. Thus, monitoring changes in chlorophyll fluorescence, instead of conducting radioactive transport assays, represents an easy-to-handle and fast alternative evaluating cuticular barrier properties of different genotypes. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. Copyright © 2016 Elsevier B.V. All rights reserved.

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

PubMed

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

2017-09-01

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

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

NASA Astrophysics Data System (ADS)

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

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

PubMed Central

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

2012-01-01

AIM: To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests. METHODS: This transversal study included 85 children residing in a slum and 43 children from a private school, all aged between 6 and 10 years, in Osasco, Brazil. For characterization of the groups, data regarding the socioeconomic status and basic housing sanitary conditions were collected. Anthropometric data was obtained in children from both groups. All children completed the hydrogen (H2) and methane (CH4) breath test in order to assess small intestinal bacterial overgrowth (SIBO). SIBO was diagnosed when there was an increase in H2 ≥ 20 ppm or CH4 ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion. RESULTS: Children from the slum group had worse living conditions and lower nutritional indices than children from the private school. SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P = 0.0007). Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P = 0.007). A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO. Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001). Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum. Colonic production of hydrogen was lower in methane-producing children (P = 0.017). CONCLUSION: Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production. Hydrogen is a substrate for

In vitro effects of anthocyanidins on sinonasal epithelial nitric oxide production and bacterial physiology

PubMed Central

Hariri, Benjamin M.; Payne, Sakeena J.; Chen, Bei; Mansfield, Corrine; Doghramji, Laurel J.; Adappa, Nithin D.; Palmer, James N.; Kennedy, David W.; Niv, Masha Y.

2016-01-01

Background: T2R bitter taste receptors play a crucial role in sinonasal innate immunity by upregulating mucociliary clearance and nitric oxide (NO) production in response to bitter gram-negative quorum-sensing molecules in the airway surface liquid. Previous studies showed that phytochemical flavonoid metabolites, known as anthocyanidins, taste bitter and have antibacterial effects. Our objectives were to examine the effects of anthocyanidins on NO production by human sinonasal epithelial cells and ciliary beat frequency, and their impact on common sinonasal pathogens Pseudomonas aeruginosa and Staphylococcus aureus. Methods: Ciliary beat frequency and NO production were measured by using digital imaging of differentiated air-liquid interface cultures prepared from primary human cells isolated from residual surgical material. Plate-based assays were used to determine the effects of anthocyanidins on bacterial swimming and swarming motility. Biofilm formation and planktonic growth were also assessed. Results: Anthocyanidin compounds triggered epithelial cells to produce NO but not through T2R receptors. However, anthocyanidins did not impact ciliary beat frequency. Furthermore, they did not reduce biofilm formation or planktonic growth of P. aeruginosa. In S. aureus, they did not reduce planktonic growth, and only one compound had minimal antibiofilm effects. The anthocyanidin delphinidin and anthocyanin keracyanin were found to promote bacterial swimming, whereas anthocyanidin cyanidin and flavonoid myricetin did not. No compounds that were tested inhibited bacterial swarming. Conclusion: Results of this study indicated that, although anthocyanidins may elicited an innate immune NO response from human cells, they do not cause an increase in ciliary beating and they may also cause a pathogenicity-enhancing effect in P. aeruginosa. Additional studies are necessary to understand how this would affect the use of anthocyanidins as therapeutics. This study emphasized the

Investigating alternative strategies for managing bacterial angular leaf spot in strawberry nursery production

USDA-ARS?s Scientific Manuscript database

The focus of this article is to discuss some of the approaches we have tested for managing the bacterial pathogen Xanthomonas fragariae in infected strawberry nursery stock. X. fragariae causes angular leaf spot (ALS) in strawberry. The pathogen is transmitted to production fields almost exclusively...

SoftWAXS: a computational tool for modeling wide-angle X-ray solution scattering from biomolecules.

PubMed

Bardhan, Jaydeep; Park, Sanghyun; Makowski, Lee

2009-10-01

This paper describes a computational approach to estimating wide-angle X-ray solution scattering (WAXS) from proteins, which has been implemented in a computer program called SoftWAXS. The accuracy and efficiency of SoftWAXS are analyzed for analytically solvable model problems as well as for proteins. Key features of the approach include a numerical procedure for performing the required spherical averaging and explicit representation of the solute-solvent boundary and the surface of the hydration layer. These features allow the Fourier transform of the excluded volume and hydration layer to be computed directly and with high accuracy. This approach will allow future investigation of different treatments of the electron density in the hydration shell. Numerical results illustrate the differences between this approach to modeling the excluded volume and a widely used model that treats the excluded-volume function as a sum of Gaussians representing the individual atomic excluded volumes. Comparison of the results obtained here with those from explicit-solvent molecular dynamics clarifies shortcomings inherent to the representation of solvent as a time-averaged electron-density profile. In addition, an assessment is made of how the calculated scattering patterns depend on input parameters such as the solute-atom radii, the width of the hydration shell and the hydration-layer contrast. These results suggest that obtaining predictive calculations of high-resolution WAXS patterns may require sophisticated treatments of solvent.

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

PubMed

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

2008-11-01

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

Allelopathic Monoterpenes Interfere with Arabidopsis thaliana Cuticular Waxes and Enhance Transpiration

PubMed Central

Kussmann, Petra; Knop, Mona; Kriegs, Bettina; Gresens, Frank; Eichert, Thomas; Ulbrich, Andreas; Marx, Friedhelm; Fabricius, Heinz; Goldbach, Heiner; Noga, Georg

2007-01-01

Exposure to the allelopathic monoterpenes camphor (100 mg/10 L) and menthol (50 mg/10 L) for 24 h enhanced transpiration of Arabidopsis thaliana fully developed rosette leaves similar to de-waxing. As ascertained by ESEM analyses the leaf surfaces were spotted with platelet like structures which seem to be partly mixed with the lipophilic epicuticular layers. The structures are supposed to contain the condensed monoterpenes, which could be identified by GC. Long term exposure (more than 48 h) to 100 mg/50 mg killed the plants by desiccation, a 24 h exposure caused necrotic spots that became visible one to two days after the treatment. Examinations of the stomatal apertures indicated that monoterpenes induced stomatal opening followed by extreme swelling and a final break down of the protoplasts. Exposure of Arabidopsis thaliana to volatiles of Mentha piperita, Lavandula latifolia and Artemisia camphorata resulted in a dramatic increase of the stomata aperture but swelling of the protoplasts was less exhibited. In contrast to de-waxing, expression of the fatty acid condensing enzyme encoding CER6 gene and de novo synthesis of CER6 protein was not induced after 24 h of exposure to the monoterpenes. The aim of the study was to demonstrate that the lipophilic layers of the leaf surface and the stomata are primary targets of monoterpene allelopathic attack. Enhanced transpiration results from a combination of affected lipophilic wax layers and a disturbed stomata function. PMID:19516993

Reduction of bacterial volatile sulfur compound production by licoricidin and licorisoflavan A from licorice.

PubMed

Tanabe, Shin-ichi; Desjardins, Jacynthe; Bergeron, Chantal; Gafner, Stefan; Villinski, Jacquelyn R; Grenier, Daniel

2012-03-01

Halitosis affects a large proportion of the population and is, in most cases, caused by the production of volatile sulfur compounds (VSCs), particularly methyl mercaptan and hydrogen sulfide, by specific bacterial species colonizing the oral cavity. In this study, a supercritical extract of Chinese licorice (Glycyrrhiza uralensis), and its major isoflavans, licoricidin and licorisoflavan A, were investigated for their effect on growth, VSC production and protease activity of Porphyromonas gingivalis, Prevotella intermedia and Solobacterium moorei, which have been associated with halitosis. The effects of licorice extract, licoricidin, and licorisoflavan A on VSC production in a saliva model were also tested. We first showed that licoricidin and licorisoflavan A, and to a lesser extent the licorice extract, were effective in inhibiting the growth of all three bacterial species, with minimal inhibitory concentrations in the range of 2-80 µg ml(-1). The licorice extract and the two isolates licoricidin and licorisoflavan A, were able to dose-dependently reduce VSC production by P. gingivalis, Prev. intermedia, and S. moorei as well as by a human saliva model. Although the extract and isolates did not inhibit the proteolytic activity of bacteria, they blocked the conversion of cysteine into hydrogen sulfide by Prev. intermedia. Lastly, the deodorizing effects of the licorice extract, licoricidin, and licorisoflavan A were demonstrated, as they can neutralize P. gingivalis-derived VSCs. Licorisoflavan A (10 µg ml(-1)) was found to be the most effective by reducing VSC levels by 50%. Within the limitations of this study, it can be concluded that a licorice supercritical extract and its major isoflavans (licoricidin and licorisoflavan A) represent natural ingredients with a potential for reducing bacterial VSC production and therefore for controlling halitosis.

Spatial and Temporal Patterns in the Carbon Isotopic Signal of Leaf Wax Aerosols in Continental Air Masses: Linkages with Ecosystem Discrimination

NASA Astrophysics Data System (ADS)

Weber, J.; Conte, M. H.

2006-12-01

Temporal and spatial variations in the concentration and isotopic composition of atmospheric carbon dioxide can be used to estimate the relative magnitudes of the terrestrial and oceanic carbon sinks. An important model parameter is the terrestrial photosynthetic carbon isotopic fractionation of CO2 (Δ), yet estimating Δ over the large spatial scales required by models remains problematic. Epiculticular leaf waxes appear to closely reflect the plant's carbon isotopic discrimination; therefore, the ablated wax aerosols present in well-mixed continental air masses may be used as a proxy to estimate the magnitude of Δ integrated over large (subcontinental) spatial scales. Over the last several years, we have been conducting time-series studies of wax aerosol molecular and isotopic composition at strategically located sites (Maine, northern Alaska, Florida, Bermuda, Barbados) which receive continental air masses passing over major terrestrial biomes (northern temperate/ecotonal boreal forests, tundra, southern US pine/hardwood forests, North American and north African). In this presentation, we describe and contrast patterns of wax aerosol-derived estimates of Δ at these sites. In North American air masses, estimates of Δ range from 14.5-20.5 using the concentration-weighted average δ13C of wax n-acids and from 13.5-19.5 for the wax n-alcohols. Seasonal trends observed in the Florida (southern US) and Bermuda samples (mixed North American air masses) indicate maximum discrimination in early spring and minimum discrimination during the summer dry season. In northern US and high latitude air masses, seasonal trends are less pronounced but in general temporally offset with highest discrimination occurring during late summer. At Barbados, which is dominated by north African air masses passing over regions largely comprised of arid C4 grasslands, estimated Δ for the wax n-acids is significantly lower (14.0-15.5 per mil), consistent with a higher predominance of C4

Production of nano bacterial cellulose from waste water of candied jujube-processing industry using Acetobacter xylinum.

PubMed

Li, Zheng; Wang, Lifen; Hua, Jiachuan; Jia, Shiru; Zhang, Jianfei; Liu, Hao

2015-04-20

The work is aimed to investigate the suitability of waste water of candied jujube-processing industry for the production of bacterial cellulose (BC) by Gluconacetobacter xylinum CGMCC No.2955 and to study the structure properties of bacterial cellulose membranes. After acid pretreatment, the glucose of hydrolysate was higher than that of waste water of candied jujube. The volumetric yield of bacterial cellulose in hydrolysate was 2.25 g/L, which was 1.5-folds of that in waste water of candied jujube. The structures indicated that the fiber size distribution was 3-14 nm in those media with an average diameter being around 5.9 nm. The crystallinity index of BC from pretreatment medium was lower than that of without pretreatment medium and BCs from various media had similar chemical binding. Ammonium citrate was a key factor for improving production yield and the crystallinity index of BC. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 (/sup 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 ofmore » 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.« less

Monitoring agrochemical diffusion through cuticle wax with coherent Raman scattering

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

Accelerated Thermal Cycling Test of Microencapsulated Paraffin Wax/Polyaniline Made by Simple Preparation Method for Solar Thermal Energy Storage.

PubMed

Silakhori, Mahyar; Naghavi, Mohammad Sajad; Metselaar, Hendrik Simon Cornelis; Mahlia, Teuku Meurah Indra; Fauzi, Hadi; Mehrali, Mohammad

2013-04-29

Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA). The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC). Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR), and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM). It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems.

Studies on the compressibility of wax matrix granules of acetaminophen and their admixtures with various tableting bases.

PubMed

Uhumwangho, M U; Okor, R S

2006-04-01

Matrix granules of acetaminophen have been formed by a melt granulation process whereby the acetaminophen powder was triturated with the melted wax--goat wax, glyceryl monostearate or carnuba wax. The compressibility of the matrix granules and their admixture, with diluent granules (lactose, alpha-cellulose or microcrystalline cellulose) was investigated. The granules were compressed to tablets at a constant load (30 arbitrary units on the load scale) of a manesty single punch machine. Resulting tablets were evaluated for tensile strength (T) and disintegration times (DT). Granule flow was determined by measuring their angle of repose when allowed to fall freely on a level surface. Matrix granules prepared by melt granulation with goat wax or glyceryl monostearate were too sticky and therefore did not flow at all. They were also poorly compressible (T values = 0.20MN/m2). Inclusion of the diluent remarkably improved granule flow property and compressibility. The T values of the tablets (measure of compressibility) increased from about 0.24 to 0.65 MN/m2 during increase in diluent (lactose) content from 20 to 80 %w/w. Microcrystalline cellulose and alpha-cellulose were more effective than lactose in promoting compressibility of the granules. By contrast the matrix granules formed with carnuba wax were free flowing (angle of repose, 18.60). Addition of the diluent further improved flowability slightly. The matrix granules (without a diluent) were readily compressible (T value, 1.79MN/m2). Addition of the diluent (80%w/w) reduced T values (MN/m2) slightly to 1.32 (lactose), 1.48 (alpha-cellulose) and 1.74 (microcrystalline cellulose). Tablets of the matrix granules only, disintegrated rapidly within 3 minutes. DT was further reduced to <30 s by addition of any of the diluents. The indication is that the inclusion of the diluents studied can be used to improve the compressibility of the otherwise poorly compressible matrix granules. Based on the flowability

Magnetic field tunable ac electrical transport of LaFeO3-wax nanocomposites

NASA Astrophysics Data System (ADS)

Roy, Supratim; Mandal, S. K.; Debnath, Rajesh; Nath, Debajyoti; Dey, P.

2018-04-01

Single phase perovskite LaFeO3 nanoparticles have been prepared through chemical pyrophoric reaction process. It is further grinded with paraffin wax of quantity 0.5 wt% of total composition to obtain an organic composite 99.5%LaFeO3-0.5%Wax. Studies of ac electrical properties viz. complex impedance, dielectric response, loss coefficient have been done in presence of external dc magnetic field, which reveals a good magnetoimpedance (˜221%) and a negative magnetodielectric (˜ 64%). The value of impedance, its real and imaginary part is observed to increase with dc field. The composite exhibits high dielectric constant (˜4760). The ac conductivity is found to decrease with applied field and increase with ac frequency.

Variability of Plant Wax Concentrations and Carbon Isotope Values in Surface Lake Sediments Provide Clues into Their Transport and Deposition

NASA Astrophysics Data System (ADS)

Bates, B.; Lowell, T. V.; Diefendorf, A. F.; Freimuth, E. J.; Stewart, A. K.

2017-12-01

Plant wax compounds preserved in lake sediments are used as proxies for paleohydrologic reconstructions. Despite their presence in lake sediments, little is known about their transport from plants to their deposition in lake sediments. By drawing on the leaf and pollen taphonomy literature combined with sediment focusing models, it is possible to develop several working hypotheses for the transport and deposition of plant waxes in lake sediments. An improved understanding of plant wax transport and deposition into lake sediments is necessary to increase the accuracy of paleohydrologic reconstructions. To better understand the controls on plant wax transport and deposition in lake sediment, we analyzed the sedimentary plant waxes from 3 lakes in the Adirondack Mountains of New York. These lakes were chosen to capture a range of basin-specific properties to evaluate their influences on the transport and deposition of plant wax compounds in surface sediments. We spatially characterized sediment properties with surface sediment samples and high-resolution underwater imaging, acoustically profiled the sub-bottom, and measured temperature profiles. From each site, we measured n-alkanes, bulk organic content (loss-on-ignition), bulk carbon and nitrogen concentrations, C:N ratios, and bulk carbon isotopes. Preliminary n-alkane concentrations and chain length distributions, as well as bulk carbon isotopes, are variable within each lake basin suggesting a mix of aquatic and terrestrial sources. The bulk carbon isotope values for two of the three lakes show a similar range of -2‰ compared to a range of -6.3‰ at the third lake. Likewise, the range of total n-alkane concentrations is much higher in the third lake suggesting that the controls on the distribution of n-alkanes and organic carbon are different between lakes. For terrestrial plant waxes, we find low n-alkane concentrations in sandy nearshore sediments relative to higher n-alkane concentrations in deeper fine

A comparison of the accuracy of patterns processed from an inlay casting wax, an auto-polymerized resin and a light-cured resin pattern material.

PubMed

Rajagopal, Praveen; Chitre, Vidya; Aras, Meena A

2012-01-01

Traditionally, inlay casting waxes have been used to fabricate patterns for castings. Newer resin pattern materials offer greater rigidity and strength, allowing easier laboratory and intraoral adjustment without the fear of pattern damage. They also claim to possess a greater dimensional stability when compared to inlay wax. This study attempted to determine and compare the marginal accuracy of patterns fabricated from an inlay casting wax, an autopolymerized pattern resin and a light polymerized pattern resin on storage off the die for varying time intervals. Ten patterns each were fabricated from an inlay casting wax (GC Corp., Tokyo, Japan), an autopolymerized resin pattern material (Pattern resin, GC Corp, Tokyo, Japan) and a light-cured resin pattern material (Palavit GLC, Hereaus Kulzer GmbH, Germany). The completed patterns were stored off the die at room temperature. Marginal gaps were evaluated by reseating the patterns on their respective dies and observing it under a stereomicroscope at 1, 12, and 24 h intervals after pattern fabrication. The results revealed that the inlay wax showed a significantly greater marginal discrepancy at the 12 and 24 h intervals. The autopolymerized resin showed an initial (at 1 h) marginal discrepancy slightly greater than inlay wax, but showed a significantly less marginal gap (as compared to inlay wax) at the other two time intervals. The light-cured resin proved to be significantly more dimensionally stable, and showed minimal change during the storage period. The resin pattern materials studied, undergo a significantly less dimensional change than the inlay waxes on prolonged storage. They would possibly be a better alternative to inlay wax in situations requiring high precision or when delayed investment (more than 1 h) of patterns can be expected.

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

PubMed

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.

RNA-Seq reveals leaf cuticular wax-related genes in Welsh onion.

PubMed

Liu, Qianchun; Wen, Changlong; Zhao, Hong; Zhang, Liying; Wang, Jian; Wang, Yongqin

2014-01-01

The waxy cuticle plays a very important role in plant resistance to various biotic and abiotic stresses and is an important characteristic of Welsh onions. Two different types of biangan Welsh onions (BG) were selected for this study: BG, a wild-type covered by wax, which forms a continuous lipid membrane on its epidermal cells, and GLBG, a glossy mutant of BG whose epidermal cells are not covered by wax. To elucidate the waxy cuticle-related gene expression changes, we used RNA-Seq to compare these two Welsh onion varieties with distinct differences in cuticular wax. The de novo assembly yielded 42,881 putative unigenes, 25.41% of which are longer than 1,000 bp. Among the high-quality unique sequences, 22,289 (52.0%) had at least one significant match to an existing gene model. A total of 798 genes, representing 1.86% of the total putative unigenes, were differentially expressed between these two Welsh onion varieties. The expression patterns of four important unigenes that are related to waxy cuticle biosynthesis were confirmed by RT-qPCR and COG class annotation, which demonstrated that these genes play an important role in defense mechanisms and lipid transport and metabolism. To our knowledge, this study is the first exploration of the Welsh onion waxy cuticle. These results may help to reveal the molecular mechanisms underlying the waxy cuticle and will be useful for waxy gene cloning, genetics and breeding as well as phylogenetic and evolutionary studies of the Welsh onion.

RNA-Seq Reveals Leaf Cuticular Wax-Related Genes in Welsh Onion

PubMed Central

Zhao, Hong; Zhang, Liying; Wang, Jian; Wang, Yongqin

2014-01-01

The waxy cuticle plays a very important role in plant resistance to various biotic and abiotic stresses and is an important characteristic of Welsh onions. Two different types of biangan Welsh onions (BG) were selected for this study: BG, a wild-type covered by wax, which forms a continuous lipid membrane on its epidermal cells, and GLBG, a glossy mutant of BG whose epidermal cells are not covered by wax. To elucidate the waxy cuticle-related gene expression changes, we used RNA-Seq to compare these two Welsh onion varieties with distinct differences in cuticular wax. The de novo assembly yielded 42,881 putative unigenes, 25.41% of which are longer than 1,000 bp. Among the high-quality unique sequences, 22,289 (52.0%) had at least one significant match to an existing gene model. A total of 798 genes, representing 1.86% of the total putative unigenes, were differentially expressed between these two Welsh onion varieties. The expression patterns of four important unigenes that are related to waxy cuticle biosynthesis were confirmed by RT-qPCR and COG class annotation, which demonstrated that these genes play an important role in defense mechanisms and lipid transport and metabolism. To our knowledge, this study is the first exploration of the Welsh onion waxy cuticle. These results may help to reveal the molecular mechanisms underlying the waxy cuticle and will be useful for waxy gene cloning, genetics and breeding as well as phylogenetic and evolutionary studies of the Welsh onion. PMID:25415343

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

PubMed

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

2007-10-01

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

Composition of the epicuticular waxes coating the adaxial side of Phyllostachys aurea leaves: Identification of very-long-chain primary amides.

PubMed

Racovita, Radu C; Jetter, Reinhard

2016-10-01

The present study presents comprehensive chemical analyses of cuticular wax mixtures of the bamboo Phyllostachys aurea. The epicuticular and intracuticular waxes were sampled selectively from the adaxial side of leaves on young and old plants and investigated by gas chromatography-mass spectrometry and flame ionization detection. The epi- and intracuticular layers on young and old leaves had wax loads ranging from 1.7 μg/cm(2) to 1.9 μg/cm(2). Typical very-long-chain aliphatic wax constituents were found with characteristic chain length patterns, including alkyl esters (primarily C48), alkanes (primarily C29), fatty acids (primarily C28 and C16), primary alcohols (primarily C28) and aldehydes (primarily C30). Alicyclic wax components were identified as tocopherols and triterpenoids, including substantial amounts of triterpenoid esters. Alkyl esters, alkanes, fatty acids and aldehydes were found in greater amounts in the epicuticular layer, while primary alcohols and most terpenoids accumulated more in the intracuticular wax. Alkyl esters occurred as mixtures of metamers, combining C20 alcohol with various acids into shorter ester homologs (C36C40), and a wide range of alcohols with C22 and C24 acids into longer esters (C42C52). Primary amides were identified, with a characteristic chain length profile peaking at C30. The amides were present exclusively in the epicuticular layer and thus at or near the surface, where they may affect plant-herbivore or plant-pathogen interactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrastructure of Wax-Producing Structures on the Integument of the Melaleuca Psyllid Boreioglycaspis melaleucae (Hemiptera: Psyllidae), with Honeydew Excretion Behavior in Males and Females

PubMed Central

Ammar, El-Desouky; Hentz, Matthew; Hall, David G.; Shatters, Robert G.

2015-01-01

The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae), was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of ‘naturally waxed’ and ‘dewaxed’ nymphs (cleaned from wax) revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s) of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed. PMID:25793934

Polyester Wax: A New Embedding Medium for the Histopathologic Study of Human Temporal Bones

PubMed Central

Merchant, Saumil N.; Burgess, Barbara; O'Malley, Jennifer; Jones, Diane; Adams, Joe C.

2007-01-01

Background Celloidin and paraffin are the two common embedding mediums used for histopathologic study of the human temporal bone by light microscopy. Although celloidin embedding permits excellent morphologic assessment, celloidin is difficult to remove, and there are significant restrictions on success with immunostaining. Embedding in paraffin allows immunostaining to be performed, but preservation of cellular detail within the membranous labyrinth is relatively poor. Objectives/Hypothesis Polyester wax is an embedding medium that has a low melting point (37°C), is soluble in most organic solvents, is water tolerant, and sections easily. We hypothesized that embedding in polyester wax would permit good preservation of the morphology of the membranous labyrinth and, at the same time, allow the study of proteins by immunostaining. Methods Nine temporal bones from individuals aged 1 to 94 years removed 2 to 31 hours postmortem, from subjects who had no history of otologic disease, were used. The bones were fixed using 10% formalin, decal-cified using EDTA, embedded in polyester wax, and serially sectioned at a thickness of 8 to 12 μm on a rotary microtome. The block and knife were cooled with frozen CO2 (dry ice) held in a funnel above the block. Sections were placed on glass slides coated with a solution of 1% fish gelatin and 1% bovine albumin, followed by staining of selected sections with hematoxylin and eosin (H&E). Immunostaining was also performed on selected sections using antibodies to 200 kD neurofilament and Na-K-ATPase. Results Polyester wax–embedded sections demonstrated good preservation of cellular detail of the organ of Corti and other structures of the membranous labyrinth, as well as the surrounding otic capsule. The protocol described in this paper was reliable and consistently yielded sections of good quality. Immuno-staining was successful with both antibodies. Conclusion The use of polyester wax as an embedding medium for human temporal

Silencing of the potato StNAC103 gene enhances the accumulation of suberin polyester and associated wax in tuber skin

PubMed Central

Verdaguer, Roger; Soler, Marçal; Serra, Olga; Garrote, Aïda; Fernández, Sandra; Company-Arumí, Dolors; Anticó, Enriqueta; Molinas, Marisa; Figueras, Mercè

2016-01-01

Suberin and wax deposited in the cork (phellem) layer of the periderm form the lipophilic barrier that protects mature plant organs. Periderm lipids have been widely studied for their protective function with regards to dehydration and for how they respond to environmental stresses and wounding. However, despite advances in the biosynthetic pathways of suberin and associated wax, little is known about the regulation of their deposition. Here, we report on a potato NAC transcription factor gene, StNAC103, induced in the tuber phellem (skin). The StNAC103 promoter is active in cells undergoing suberization such as in the basal layer of the phellem, but also in the root apical meristem. Gene silencing in potato periderm correlates with an increase in the suberin and wax load, and specifically in alkanes, ω-hydroxyacids, diacids, ferulic acid, and primary alcohols. Concomitantly, silenced lines also showed up-regulation of key genes related to the biosynthesis and transport of suberin and wax in the tuber periderm. Taken together, our results suggest that StNAC103 has a role in the tight regulation of the formation of apoplastic barriers and is, to the best of our knowledge, the first candidate gene to be identified as being involved in the repression of suberin and wax deposition. PMID:27520790

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

PubMed

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.

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.

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 totalmore » 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 microbial lipid production. We also find that the utility of some of these

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production.

PubMed

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

2017-05-23

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 in Rhodobacter sphaeroides By screening an R. sphaeroides Tn 5 mutant 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. IMPORTANCE This 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 microbial lipid production. We also find that the utility of some of these alterations can be

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

DOE PAGES

Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.; ...

2017-05-23

ABSTRACT Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation inRhodobacter sphaeroides. By screening anR. sphaeroidesTn5mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their totalmore » 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 microbial lipid production. We also find that the utility of some of these

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

PubMed

Rohde, Christine; Resch, Grégory; Pirnay, Jean-Paul; Blasdel, Bob G; Debarbieux, Laurent; Gelman, Daniel; Górski, Andrzej; Hazan, Ronen; Huys, Isabelle; Kakabadze, Elene; Łobocka, Małgorzata; Maestri, Alice; Almeida, Gabriel Magno de Freitas; Makalatia, Khatuna; Malik, Danish J; Mašlaňová, Ivana; Merabishvili, Maia; Pantucek, Roman; Rose, Thomas; Štveráková, Dana; Van Raemdonck, Hilde; Verbeken, Gilbert; Chanishvili, Nina

2018-04-05

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

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

PubMed Central

Rohde, Christine; Resch, Grégory; Blasdel, Bob G.; Gelman, Daniel; Górski, Andrzej; Hazan, Ronen; Huys, Isabelle; Kakabadze, Elene; Łobocka, Małgorzata; Maestri, Alice; Makalatia, Khatuna; Malik, Danish J.; Mašlaňová, Ivana; Merabishvili, Maia; Rose, Thomas; Štveráková, Dana; Van Raemdonck, Hilde; Verbeken, Gilbert; Chanishvili, Nina

2018-01-01

Phage therapy is increasingly put forward as a “new” potential tool in the fight against antibiotic resistant infections. During the “Centennial Celebration of Bacteriophage Research” conference in Tbilisi, Georgia on 26–29 June 2017, an international group of phage researchers committed to elaborate an expert opinion on three contentious phage therapy related issues that are hampering clinical progress in the field of phage therapy. This paper explores and discusses bacterial phage resistance, phage training and the presence of prophages in bacterial production strains while reviewing relevant research findings and experiences. Our purpose is to inform phage therapy stakeholders such as policy makers, officials of the competent authorities for medicines, phage researchers and phage producers, and members of the pharmaceutical industry. This brief also points out potential avenues for future phage therapy research and development as it specifically addresses those overarching questions that currently call for attention whenever phages go into purification processes for application. PMID:29621199

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

PubMed Central

van Agtmaal, Maaike; van Os, Gera J.; Hol, W.H. Gera; Hundscheid, Maria P.J.; Runia, Willemien T.; Hordijk, Cornelis A.; de Boer, Wietse

2015-01-01

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

Alkanes in flower surface waxes of Momordica cochinchinensis influence attraction to Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae).

PubMed

Mukherjee, A; Sarkar, N; Barik, A

2013-08-01

Extraction, thin-layer chromatography, and gas chromatography-mass spectrophotometry analyses revealed 15 alkanes representing 97.14% of the total alkanes in the surface waxes of Momordica cochinchinensis Spreng flowers. Nonacosane was the prevailing alkane followed by hexatriacontane, nonadecane, heptacosane, and hentriacontane, accounting for 39.08%, 24.24%, 13.52%, 6.32%, and 5.12%, respectively. The alkanes from flower surface waxes followed by a synthetic mixture of alkanes mimicking alkanes of flower surface waxes elicited attraction of the female insect, Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) between 2 and 10-μg/mL concentrations in a Y-shaped glass tube olfactometer bioassay under laboratory conditions. Synthetic nonadecane from 178.28-891.37 ng, heptacosane from 118.14-590.72 ng, and nonacosane at 784.73 ng showed attraction of the insect. A synthetic mixture of 534.82 ng nonadecane, 354.43 ng heptacosane, and 2,354.18 ng nonacosane elicited highest attraction of A. foveicollis.

Low-pressure hydrocracking of coal-derived Fischer-Tropsch waxes to diesel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dieter Leckel

2007-06-15

Coal-derived low-temperature Fischer-Tropsch (LTFT) wax was hydrocracked at pressures of 3.5-7.0 MPa using silica-alumina-supported sulfided NiW/NiMo and an unsulfided noble metal catalyst, modified with MoO{sub 3}. A low-pressure operation at 3.5 MPa produced a highly isomerized diesel, having low cloud points (from -12 to -28{sup o}C) combined with high cetane numbers (69-73). These properties together with the extremely low sulfur ({lt}5 ppm) and aromatic ({lt}0.5%) contents place coal/liquid (CTL) derived distillates as highly valuable blending components to achieve Eurograde diesel specifications. The upgrading of coal-based LTFT waxes through hydrocracking to high-quality diesel fuel blend components in combination with commercial-feasible coal-integratedmore » gasification combined cycle (coal-IGCC) CO{sub 2} capture and storage schemes should make CTL technology more attractive. 28 refs., 7 figs., 8 tabs.« less

Accelerated Thermal Cycling Test of Microencapsulated Paraffin Wax/Polyaniline Made by Simple Preparation Method for Solar Thermal Energy Storage

PubMed Central

Silakhori, Mahyar; Naghavi, Mohammad Sajad; Metselaar, Hendrik Simon Cornelis; Mahlia, Teuku Meurah Indra; Fauzi, Hadi; Mehrali, Mohammad

2013-01-01

Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA). The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC). Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR), and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM). It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems. PMID:28809232

Light-Stimulated Bacterial Production and Amino Acid Assimilation by Cyanobacteria and Other Microbes in the North Atlantic Ocean▿

PubMed Central

Michelou, Vanessa K.; Cottrell, Matthew T.; Kirchman, David L.

2007-01-01

We examined the contribution of photoheterotrophic microbes—those capable of light-mediated assimilation of organic compounds—to bacterial production and amino acid assimilation along a transect from Florida to Iceland from 28 May to 9 July 2005. Bacterial production (leucine incorporation at a 20 nM final concentration) was on average 30% higher in light than in dark-incubated samples, but the effect varied greatly (3% to 60%). To further characterize this light effect, we examined the abundance of potential photoheterotrophs and measured their contribution to bacterial production and amino acid assimilation (0.5 nM addition) using flow cytometry. Prochlorococcus and Synechococcus were abundant in surface waters where light-dependent leucine incorporation was observed, whereas aerobic anoxygenic phototrophic bacteria were abundant but did not correlate with the light effect. The per-cell assimilation rates of Prochlorococcus and Synechococcus were comparable to or higher than those of other prokaryotes, especially in the light. Picoeukaryotes also took up leucine (20 nM) and other amino acids (0.5 nM), but rates normalized to biovolume were much lower than those of prokaryotes. Prochlorococcus was responsible for 80% of light-stimulated bacterial production and amino acid assimilation in surface waters south of the Azores, while Synechococcus accounted for on average 12% of total assimilation. However, nearly 40% of the light-stimulated leucine assimilation was not accounted for by these groups, suggesting that assimilation by other microbes is also affected by light. Our results clarify the contribution of cyanobacteria to photoheterotrophy and highlight the potential role of other photoheterotrophs in biomass production and dissolved-organic-matter assimilation. PMID:17630296