1 株金黄色葡萄球菌烈性噬菌体的生物学特性及其裂解效果

以耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus，MRSA）为宿主菌从奶牛养殖场污水中分离到1 株烈性噬菌体P65。透射电镜表明，噬菌体P65头部呈多面体结构，属于有尾噬菌体目长尾噬菌体科。噬菌体P65最佳感染复数为0.01，一步生长曲线显示，噬菌体P65潜伏期为10 min，裂解周期为90 min，裂解量为35.46 PFU/cell。在pH 4～10和温度30～45 ℃条件下具有稳定的裂解活性。紫外线照射70 min后，噬菌体P65效价由1.91×108 PFU/mL降至2.65×104 PFU/mL。经噬菌体处理48 h后，菌株MRSA 2和MRSA 24的生物被膜清除率分别为91.3%和92.2%。在25 ℃条件下，噬菌体P65在牛奶和牛肉细菌污染模型中有一定的抑菌效果。本研究表明噬菌体P65具有较宽的宿主谱和稳定的裂解杀菌能力，在清除生物被膜和食品抗菌方面有一定的运用潜能。     

烈性青枯雷尔氏菌噬菌体的分离与生物学特性分析

为采用噬菌体疗法防治烟草青枯病,以烟草青枯菌TB15-15为宿主菌,从土壤中筛选分离得到噬菌体,并采用双层平板法检测了噬菌体的效价、最佳感染复数(MOI)、一步生长曲线以及噬菌体对温度和酸碱度的敏感性。结果表明:从长期植烟田块土壤中分离得到1株青枯雷尔氏菌烈性噬菌体,命名为RS-PⅡ-1。经检测该噬菌体最佳感染复数为1;一步生长曲线显示噬菌体潜伏期为10 min,爆发期持续100 min,裂解量为1 411;该噬菌体40℃活性最高,裂解量也最大,当温度超过40℃时活性逐渐下降,直至在60℃时活性丧失;噬菌体对酸碱均具有一定的耐受能力,pH在4~8范围内噬菌体均有很好裂解活性,当p H小于4或大于8,裂解活性均减小,特别是在p H大于11时,噬菌体裂解活性完全丧失,因此噬菌体RS-PⅡ-1不适合与碱性溶液混合应用。     

一株沙门氏菌噬菌体SalmpYZU27的生理学特性及其在牛奶和鸡肉中的抑菌作用研究

目的 分离鉴定沙门氏菌裂解性噬菌体,并研究其生理学特性及抑菌能力。方法 以沙门氏菌SalmonellaagonaCICC21586为宿主菌,采用点斑法从农贸市场污水中分离沙门氏菌噬菌体,研究其生理学特性,并测定其在牛奶和鸡肉中的抑菌效果。结果 分离到一株沙门氏菌裂解性噬菌体Salmp YZU27,其具有宽裂解谱,可裂解鼠伤寒沙门氏菌CICC 21483、丙型副伤寒沙门氏菌CICC 21512和肠沙门氏菌2011K-1440染色体血清型N16等12株不同血清型沙门氏菌;最佳感染复数为0.001; pH在4～11时保持高活性;潜伏期为20 min,爆发期为100 min,爆发量为89 PFU/cell;在40～70℃可保持较高活性;噬菌体全基因组测序未检出致病因子和抗性基因;不同感染复数下在LB肉汤中均可抑制宿主菌至少8h,且在牛奶和鸡肉片中对宿主菌均有一定的抑制效果。结论 本研究分离鉴定的沙门氏菌噬菌体SalmpYZU27裂解谱广,酸碱耐受性较好,耐热能力强,爆发量适中,为后续噬菌体抑菌剂的研制提供理论基础。     

沙门氏菌裂解性噬菌体的分离鉴定及其生物学特性

从家禽屠宰场污水中,以肠炎沙门氏菌ATCC13076和禽沙门氏菌CVCC2184为宿主菌,分离到两株裂解性沙门氏菌噬菌体,分别命名为vB_SenM-PA13076（简称PA13076）和vB_SenM-PC2184（简称PC2184）。同时对这两株噬菌体进行了噬菌斑、噬菌谱系（含耐药菌）、形态学（透射电镜）、遗传物质、酸碱及热稳定性、最佳感染复数、一步生长曲线等生物学特性研究。结果表明：两株噬菌体的裂解空斑均透亮清晰;除对本身宿主菌产生强裂解作用,还裂解其他沙门氏菌,为宽噬菌谱,其中PA13076能强裂解一株耐氨苄青霉素ATCC13076转化菌株（A+13076）,PC2184则能裂解另一株耐氨苄青霉素CVCC2184转化菌株（A+2184）;电镜观察这两株噬菌体均为肌尾病毒科;遗传物质为dsDNA;pH值和温度耐受能力较好;PA13076、PC2184最佳感染复数分别为0.01、10,潜伏期分别为20、30 min,爆发期分别为70、60 min,平均爆发量分别为21、23。     

荧光假单胞菌噬菌体KS461-2的分离及其生物学特性研究

从2-酮基-D-葡萄糖酸产生菌荧光假单胞菌A46异常发酵液中分离得到1种噬菌体,将其命名为KS461-2。电镜观察表明,噬菌体KS461-2呈蝌蚪状。根据ICTV对病毒的分类标准,噬菌体KS461-2属长尾噬菌体科,为烈性噬菌体。噬菌体KS461-2对宿主菌的最佳感染复数为0．01,温度和pH对其稳定性具有显著的影响。一步生长曲线显示,噬菌体KS461-2的潜伏期约30min,裂解期约135min,裂解量为24。SDS-PAGE显示,噬菌体KS461-2有5种主要的结构蛋白,其分子量分别为66．0、61．0、42．5、34．7和14．4kDa。     

溶藻弧菌噬菌体Va2001的分离鉴定及其应用

为了开发水产品中溶藻弧菌的生物清除剂,以溶藻弧菌为宿主菌,从锦州市水产品市场、农贸市场、笔架山海域、超市及葫芦岛市某水产养殖场、鞍山市某养殖场等地方采集了约60份海产品及其养殖环境污水,应用双层平板法从中分离纯化获得1株烈性噬菌体,命名为Va2001。对Va2001的裂解谱、最佳感染复数（optimal multiplicity of infection）、一步生长曲线、温度和pH的稳定性等生物学特征进行了研究,并在牡蛎感染模型中测定了噬菌体对溶藻弧菌的清除效果。结果表明,该噬菌体Va2001属于有尾噬菌体目(Caudovirales),短尾噬菌体科（Podoviridae）,Va2001的裂解谱较窄,裂解率为32%,最佳感染复数为0.0001,潜伏期约为20 min,裂解期为100 min,平均裂解量为274 PFU/cell;在4~60 ℃、pH4~9范围内活性稳定。以牡蛎为感染模型的净化实验结果显示,噬菌体Va2001能够抑制养殖环境中溶藻弧菌的增长,降低牡蛎体内溶藻弧菌的含量;当养殖时间延长至72 h时,实验组中溶藻弧菌的数量降低约2个数量级。本研究的结果表明噬菌体Va2001具有良好的应用前景,可以作为海产品中溶藻弧菌的新型生物清除剂。     

一株广域pH耐受性微小噬菌体αα的分离、纯化及生理学特性分析

本研究采用双层平板法从污水中分离纯化出一株烈性沙门氏菌噬菌体αα。利用电镜观察其形态特征,通过琼脂糖凝胶电泳分析其核酸组成,并对其生理学特性进行分析,包括一步生长曲线、温度耐受性、pH耐受性、裂解谱、最佳离子浓度和最佳感染复数。结果表明,该烈性噬菌体αα有一个直径为20 nm的头部,无尾部结构,其核酸类型为单链DNA。由此推断,噬菌体αα属于微小噬菌体科。该噬菌体无明显潜伏期,裂解期为60 min,在pH2.10~11.45内和温度40~50 ℃内效价分别保持在106~108和108 pfu/mL左右,最佳感染复数值为10-4,钙镁离子均能促进该噬菌体的液体增殖,其中培养基中含10 mmol/L MgCl₂时促进效果最佳,与未添加离子的对照组相比提高了1.5个log。研究结果为噬菌体的多样性及其应用等方面的研究奠定了基础。     

Pseudomonas helleri噬菌体PrH-181的分离及生物特性分析

Pseudomonas helleri为水产品冷藏过程中的优势腐败菌。为筛选得到能裂解Pseudomonas helleri的烈性噬菌体,采用双层平板法,从采集自不同省份的70个污水和土壤样品中,分离纯化得到了1株裂解活性较强的噬菌体PrH-181。形态学和生化特征实验结果显示,该噬菌体壳体为无尾二十面体结构,对氯仿不敏感,且核酸类型鉴定为RNA。根据ICTV对病毒的分类标准,PrH-181可鉴定为光滑病毒科噬菌体。该噬菌体最佳感染复数(MOI)为0.01,一步生长曲线显示其潜伏期为20 min,爆发期为180 min,裂解量为584。该噬菌体的耐热性良好;最佳生长pH为6.0~7.0,在pH6.0~9.0时其存活率可高达94.1%~98.8%,耐碱力较耐酸力强。     

一株短乳杆菌烈性噬菌体的分离鉴定与生化特性研究

短乳杆菌是应用于食品发酵中的重要菌株，噬菌体污染是导致发酵失败的主要因素之一，对食品发酵生产有着巨大的危害。从发酵泡菜水中分离纯化短乳杆菌烈性噬菌体，研究其生物学性质。利用双层平板法分离和纯化噬菌体，通过负染色电镜形态和核酸类型鉴定。采用核酸内切酶处理后电泳鉴定核酸类型、基因组大小和包装机制。通过双层平板法测定噬菌体效价，实验测定最佳感染复数、一步生长曲线、温度和pH等物理化学因素及常见消毒剂对其存活的影响。分离纯化到1株烈性噬菌体，命名为φB23。其由多面体结构的头部和弯曲的长尾构成，φB23基因组为双链DNA,大小约为52.4 kb,包装机制为黏末端连接。最佳感染复数为0.001,潜伏期为30 min,裂解期为90 min,裂解量为(103.2±9.0) pfu/cell。常用的巴氏灭菌温度为63℃和72℃,分别处理10 min和5 min能较好地灭活；在pH 3.0～8.0保持稳定，75%乙醇处理10 min能使其丧失活性，500 mg/L次氯酸钠处理5 min能完全灭活。φB23鉴定为尾噬菌体目(Caudovirales)长尾噬菌体科(Siphoviridae)的噬菌体，表征并...     

一株耐甲氧西林金黄色葡萄球菌噬菌体qdsa002的分离鉴定及其生理学性质研究

为探究耐甲氧西林金黄色葡萄球菌的生物防治方法,从青岛市团岛污水处理厂采集到的污水中分离得到了一株噬菌体qdsa002。借助噬菌斑形态、酶切、电镜等技术对其进行了分类鉴定。研究了其最佳感染复数、一步生长曲线、p H稳定性和热稳定性等生理学特征。结果表明,qdsa002核酸属于线型双链DNA,具有正多面体的头部及较长的尾部,qdsa002头部直径约47 nm,尾长约120 nm,属肌尾噬菌体科。生理学特征研究结果表明,qdsa002在双层平板上能形成清晰透亮的噬菌斑。最佳感染复数为0.001,潜伏期40 min,爆发期180 min。在p H为5~9范围内能够保持良好的生理活性。在温度不高于50℃条件下裂解性能良好。该噬菌体可用于防治MRSA感染的生物制剂。     

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