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41.
Geotrichum candidum is a ubiquitous yeast and an essential component in the production of many soft cheeses. We developed a multilocus sequence typing (MLST) scheme with five retained loci (NUP116, URA1, URA3, SAPT4 and PLB3) which were sufficiently divergent to distinguish 40 sequence types (STs) among the 67 G. candidum strains tested. Phylogenetic analyses defined five main clades; one clade was restricted to environmental isolates, three other clades included distinct environmental isolates and dairy strains, while the fifth clade comprised 34 strains (13 STs), among which all but two were isolated from milk, cheese or the dairy environment. These findings suggest an adaptation to the dairy ecosystems by a group of specialized European G. candidum strains. In addition, we developed a polymerase chain reaction inter‐long terminal repeat scheme, a fast and reproducible random amplification of polymorphic DNA‐like method for G. candidum, to type the closely related dairy strains, which could not be distinguished by MLST. Overall, our findings distinguished two types of dairy strains, one forming a homogeneous group with little genetic diversity, and the other more closely related to environmental isolates. Neither regional nor cheese specificity was observed in the dairy G. candidum strains analysed. This present study sheds light on the genetic diversity of both dairy and environmental strains of G. candidum and thus extends previous characterizations that have focused on the cheese isolates of this species. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
42.
The effects of soaking of whole, dehulled and ground millet and soybean seeds on phytate degradation and Phy/Fe and Phy/Zn molar ratios 总被引:1,自引:0,他引:1
Isabelle Lestienne Claire Mouquet-Rivier Christèle Icard-Vernière Isabelle Rochette & Serge Trèche 《International Journal of Food Science & Technology》2005,40(4):391-399
The degradation and leaching of phytates, phytase activity and iron and zinc concentrations have been studied after soaking of whole seeds, dehulled seeds and flours of millet and soybean, in order to investigate the efficiency of soaking on reducing Phy/Fe and Phy/Zn molar ratios. When using millet grains, dehulling and milling before soaking facilitated the leaching of phytates and phytases in the aqueous medium and hence phytate degradation. Dehulling of soybean seeds led to a marked increase in phytate content, whereas milling favoured reactions between phytases and phytates. The Phy/Fe and Phy/Zn molar ratios decreased only slightly during soaking. The highest decreases for millet were obtained after soaking of flour for 8 h (Phy/Fe: 10.8–7.7 and Phy/Zn: 20.3–15.1), and after soaking of whole seeds for 24 h for soybean (Phy/Fe: 10.4–9.4 and Phy/Zn: 23.8–19.1). Cooking of flours with water used for soaking did not increase phytate degradation. 相似文献
43.
Brigitte Mouanda Veronique Eyeffa Serge Palacin 《Journal of Applied Electrochemistry》2009,39(3):313-320
An agarose gel was used as an electrochemical cell to graft vinylic polymer layers on conductive surfaces by electro-initiated
radical electrografting of various water-soluble and hydrophobic vinylic monomers in the presence of diazonium ions. The process
was followed by in situ electrochemical measurements and the resulting grafted layer was characterized by infrared (IRRAS)
and photoelectron (XPS) spectroscopy.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
44.
Sustainable Oxidative Cleavage of Vegetable Oils into Diacids by Organo-Modified Molybdenum Oxide Heterogeneous Catalysts
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![点击此处可从《Journal of the American Oil Chemists](/ch/ext_images/free.gif)
Aimé Serge Ello Amir Enferadi-kerenkan Albert Trokourey Trong-On Do 《Journal of the American Oil Chemists' Society》2017,94(12):1451-1461
Exploiting vegetable oils to produce industrially valuable diacids via an eco‐friendly process requires an efficient and recyclable catalyst. In this work, a novel catalytic system based on organo‐modified molybdenum trioxide was synthesized by a green hydrothermal method in one simple step, using Mo powder as precursor, hydrogen peroxide, and amphiphilic surfactants cetyltrimethylammonium bromide (CTAB) and tetramethylammonium bromide (TMAB) as capping agents. The synthesized materials were first characterized by different techniques including XRD, SEM, TGA, and FT‐IR. Interestingly, various morphologies were obtained depending on the nature of the surfactants and synthetic conditions. The synthesized catalysts were employed in oxidative cleavage of oleic acid, the most abundant unsaturated fatty acid, to produce azelaic and pelargonic acids with a benign oxidant, H2O2. Excellent catalytic activities resulting in full conversion of initial oleic acid were obtained, particularly for CTAB‐capped molybdenum oxide (CTAB/Mo molar ratio of 1:3) that gave 83 and 68% yields of production of azelaic and pelargonic acids, respectively. These are the highest yields that have been obtained for this reaction by heterogeneous catalysts up to now. Moreover, the CTAB‐capped catalyst could be conveniently separated from the reaction mixture by simple centrifugation and reused without significant loss of activity up to at least four cycles. 相似文献
45.
Serge SALAT 《建设科技(建设部)》2006,(24)
一、规划和设计生物气候型建筑■建筑工程项目的每一阶段都要尽量减少能量消耗设计生物气候型建筑的目的,就是要以产生尽可能少的能量消耗并充分考虑环境因素的条件在建筑物内部创造最大程度的舒适度。因此,在建筑工程项目的每一阶段内,都最大程度地减少能量消耗是非常必要的。 相似文献
46.
Fabio R.J. Vieira José F. de Rezende Valmir C. Barbosa Serge Fdida 《Computer Networks》2012,56(5):1584-1598
We consider wireless mesh networks and the problem of scheduling the links of a given set of routes under the assumption of a heavy-traffic pattern. We assume some TDMA protocol provides a background of synchronized time slots and seek to schedule the routes’ links to maximize the number of packets that get delivered to their destinations per time slot. Our approach is to construct an undirected graph G and to heuristically obtain node multicolorings for G that can be turned into efficient link schedules. In G each node represents a link to be scheduled and the edges are set up to represent every possible interference for any given set of interference assumptions. We present two multicoloring-based heuristics and study their performance through extensive simulations. One of the two heuristics is based on relaxing the notion of a node multicoloring by dynamically exploiting the availability of communication opportunities that would otherwise be wasted. We have found that, as a consequence, its performance is significantly superior to the other’s. 相似文献
47.
The Hybrid Finite Element Mixing Cell Method: A New Flexible Method for Modelling Mine Ground Water Problems 总被引:1,自引:0,他引:1
Serge Brouyère Ph. Orban S. Wildemeersch J. Couturier N. Gardin A. Dassargues 《Mine Water and the Environment》2009,28(2):102-114
Dewatering operations often stop at mine closure. The ground water rebound can have undesirable consequences, which numerical
models can help one understand and manage. However, classical modelling techniques are relatively unsuitable to these contexts.
While spatially distributed and physically based models suffer difficulties due to the lack of data and the complexity of
geological and hydrogeological conditions, black-box models are too simple to deal with the problems effectively. A new modelling
method is proposed to simulate ground water environments in which water flows through mined (exploited) and unmined (unexploited)
areas. Exploited zones are simulated using a group of mixing cells possibly interconnected by pipes. Unexploited zones are
simultaneously simulated using classical finite elements. This combined approach allows explicit calculation of ground water
flows around the mine and mean water levels in the exploited zones. Water exchanges between exploited zones and unexploited
zones are simulated in the model using specifically defined internal boundary conditions. The method is tested on synthetic
cases of increasing complexity, and first results from a real case study are presented. 相似文献
48.
Sawsan Abdul-Majid Imad Hasan Qi Zheng Ramón Maldonado-Basilio Serge Bidnyk Trevor Hall 《电信纪事》2013,68(1-2):49-55
Radio-over- fibre (RoF) technology is receiving large attention due to its ability to provide simple antenna front ends, increased capacity and increased wireless access coverage. Coherently detected RoF systems would enable the information to be carried in both the amplitude and phase or in different states of the polarisation of the optical field. Additionally, the selectivity of coherent receiver is very well suited for access networks. We present a 90° optical hybrid built on a silicon-on-insulator planar light-wave circuit, which can be used as the optical front end of the digital coherent receiver in a digitised RoF link and will lead to reduced receiver footprint and cost. The optical hybrid circuit includes 2?×?2 and 4?×?4 multimode interference (MMI) splitters, in a polarisation diversity configuration. The simulation results at vacuum wavelength 1,550 nm show polarisation independence and phase errors between the ports of less than 0.03°. The properties of the prototyped 4?×?4 MMI were measured over a wide range of wavelengths. The 2?×?2 and 4?×?4 MMI showed nearly equal splitting ratios. Measurements of the relative phase relationship between the ports for Transverse Electric mode polarisation are shown to match the simulation results. 相似文献
49.
Pichia sorbitophila grows rapidly in the presence of very high NaCl concentrations. Under these conditions, even when the K(+) concentration is low, P. sorbitophila cells can maintain low Na(+) and high K(+) contents. This remarkable capacity of P. sorbitophila fails when the external pH is not acidic. This indicates that Na(+) efflux is mediated by an electroneutral Na(+)/H(+) antiporter. We have cloned and sequenced two genes designated as PsNHA1 and PsNHA2, which probably encode two antiporters of this type. The genes present high similarity with the corresponding genes from other yeasts. The heterologous expression of PsNHA1 or PsNHA2 in a Saccharomyces cerevisiae mutant lacking the Na(+) efflux systems and sensitive to high concentrations of Na(+) and K(+) rescued the tolerance and the ability to extrude both cations. The Accession Nos of the sequenced DNA fragments are: PsNHA1, AJ496431; PsNHA2, AJ496432. (TC 2.A.36) Copyright 2002 John Wiley & Sons, Ltd. 相似文献
50.
Equations that describe the photobleaching of photochromic layers illuminated by Gaussian laser beams are given. The photochromic samples are made of thionine, triethanolamine, and polyvinyl alcohol and follow simple kinetics law. Spatial absorbance and time-dependent power transmittance are well described by the developed equations. The model is used to calculate the Gaussian dimension of helium-neon laser beams from kinetics data. 相似文献