不同木素降解成分对纤维素降解的影响

用经过驯化的瘤胃菌厌氧降解加入不同木素降解成分的纤维素，结果表明，木素中的香兰素对瘤胃微生物降解纤维素降解的启动有明显影响，但不影响其最终降解程度，香兰素对乙酸、丁酸的产生有促进作用，但对丙酸的产生有抑制作用；乙酰基愈创木酚和愈创木酚对纤维素的降解影响不大，对降解启动略有影响，愈创木酚对丙酸的产生也有抑制作用，但不如香兰素的抑制作用强，而乙酰基愈创木酚对丙酸的产生无影响。混合态的酸淅木素对纤维素降解有明显的抑制作用。     

瘤胃微生物体外驯化降解纤维素研究

实验先按照正交表L18(3^7）的设计对瘤胃微生物降解滤纸的营养和环境条件进行研究，发现在C/N为14.2/1、葡萄糖浓度低、乙酸浓度为800mg/L、无丙酸存在，温度为45℃、pH值为6.5的环境条件下，纤维素的降解校为彻底。在以上优化条件的基础上，进行了纤维降解及产酸情况的研究，发现纤维素降解的直接产物葡萄糖不会产生积累而很快就转化为挥发酸，而挥发酸会产生积累。挥发酸主要是乙酸、丙酸和丁酸三种，其中乙酸产量占到86%-93%。在纤维素降解产酸过程中，产气量并不大。     

外源酶对湖羊瘤胃微生物区系的影响

研究添加不同水平的外源酶(木聚糖酶和纤维素酶)对湖羊瘤胃液体外培养及瘤胃微生物体外培养区系的影响,旨在为外源酶作为湖羊饲料添加剂开发提供理论依据。结果表明:添加不同水平外源酶均能改善瘤胃微生物体外培养特性,其中以添加量为10mg/kg处理组效果最佳,外源酶(10mg/kg)可以有效提高培养液中细菌浓度(P0.01),产甲烷菌浓度极显著降低(P0.01),促进纤维素降解菌生长繁殖。     

冬小麦扩展蛋白TaEXPA8黑曲霉工程菌的构建及纤维素水解作用分析

农作物秸秆中大量存在的纤维素是可再生的清洁能源之一,纤维素的充分利用对于自然资源的可持续发展及环境保护有重要意义。然而,秸秆中纤维素的复杂结构使其降解工作较难开展。扩展蛋白是存在于植物及部分微生物中的一类细胞壁松弛蛋白,且来自于微生物中的扩展蛋白被证实能够提高纤维素酶的水解效率。为探究植物中扩展蛋白协同纤维素酶提高降解纤维素的能力,该研究以冬小麦扩展蛋白TaEXPA8为基础构建了黑曲霉表达载体,并以黑曲霉CICC2462为受体获得了黑曲霉工程菌pSZHGS-TaEXPA8,同时对该工程菌发酵液的纤维素水解促进作用进行了分析。结果显示,TaEXPA8基因能够在工程菌中进行正常的转录,并在发酵上清液中检测到TaEXPA8蛋白的表达,但表达量较低;工程菌的发酵液能够显著促进滤纸的崩解,水解作用产生葡萄糖的含量相比于单一纤维素酶处理提高了21.2%。该研究为植物扩展蛋白在纤维素降解中的应用提供新的思路和方法。     

纤维素的微生物降解研究进展

纤维素是自然界储量最丰富的可再生生物质原料,具有解决能源危机的巨大潜力,但结构复杂,难以降解,导致综合利用率较低.利用微生物处理技术降解纤维素,是实现其循环利用的一项重要策略.本文从单一菌株、天然复合菌群、优化组合纯培养菌株三个方面对纤维素的微生物降解进行了综述,总结归纳了每种筛选策略的优势特点和应用价值,并阐述了纤维...     

木质素的生物降解及其应用

综述了具有降解木质素能力的微生物和酶的种类及其降解特性,阐述了木质素生物降解在生物化学制浆、纸浆生物漂白、造纸废水生物处理、饲料工业、生物肥料等领域的应用现状,展望了木质素生物降解技术研究的发展趋势.     

羧甲基纤维素的制备研究及应用现状

羧甲基纤维素是一种水溶性纤维素醚,具有多种重要生物活性,广泛应用于食品、化工等领域。本文综述了羧甲基纤维素及其交联聚合物的制备工艺研究进展,阐述了羧甲基纤维素在各食品领域的应用现状,并对其发展前景进行了展望,拟为羧甲基纤维素的进一步研究奠定基础。     

苹果酸对山羊瘤胃纤维降解率及发酵类型的影响

以4头装有永久性瘤胃瘘管的本地山羊为试验动物,采用4×4拉丁方设计,研究苹果酸(0、5、10和15 g/d)对山羊瘤胃纤维降解率及瘤胃发酵类型的影响。结果表明,日粮中添加苹果酸能够显著提高瘤胃内中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的降解率(P<0.05);瘤胃液中乙酸与丙酸比值显著降低(P<0.05),改变了瘤胃发酵类型;氨态氮浓度显著降低(P<0.05),促进了瘤胃微生物对氨、氮的利用。     

基于纤维素的食品包装材料的研究进展

纤维素多数来源于植物和微生物,具有优良的生物降解性和力学性能,可在绿色食品包装材料中广泛应用.本文综述了来自于植物和微生物的木质纤维素、微纤维纤维素及细菌纤维素的提取、改性方法以及其在食品包装材料中的力学性能、阻隔性、抗菌性、降解性能等方面的相关研究.纤维素作为食品包装材料不仅拓展了纤维素的应用领域,而且为食品安全和环...     

纳米纤维素/二维材料纳米复合材料在水处理领域的应用进展

近年来,纳米纤维素在水处理领域受到广泛关注。纳米纤维素的羟基对带有离子结构的污染物表现出一定的吸引力,通过表面改性还可进一步提高其捕获能力。将纳米纤维素和石墨烯等二维材料复合能够制备高性能纳米复合材料,提高材料对污染物的选择性。本文介绍了纳米纤维素和常见的几种二维材料,综述了纳米纤维素/二维材料复合材料在水处理领域的应用,包括过滤、吸附、光催化降解3种处理方法,并对不同二维材料与纳米纤维素复合后在水处理领域应用中的差异进行了比较。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press