一株降解呕吐毒素蜡样芽孢杆菌的筛选与鉴定

目的:分离筛选能够降解呕吐毒素(deoxynivalenol,DON)的芽孢杆菌,以用于该毒素的生物降解。方法:采集霉变秸秆、土壤和粪便样品,先将样品加热80℃后,取上清液接种到以DON为唯一碳源的分离培养基富集DON降解菌。以LB培养基分离纯化富集菌,然后对分离到的菌株进行DON毒素降解能力检测。对降解能力最强的菌株进行形态学观察、生理生化实验和16S r DNA序列鉴定。结果:从16株分离菌中筛选得到一株对DON降解能力最强的菌株B.JG05,降解率最高可达80.61%,且对含DON饲料的降解率为82.68%。该菌株呈短杆状,能形成芽孢;生理生化特性符合蜡样芽孢杆菌的基本特征;16S r DNA序列进化树分析表明该菌株与蜡样芽孢杆菌的亲缘关系最近。结论:筛选获得了一株高效降解DON的蜡样芽孢杆菌B.JG05,为饲料和食品中DON毒素的生物降解提供了可能。     

降解呕吐毒素微生物的筛选鉴定及其应用

目的 筛选高效降解呕吐毒素（Deoxynivalenol,DON）的微生物并鉴定其种类。方法 分离培养出高效降解DON的微生物,鉴定该微生物种类,分析微生物各组分降解DON的效率,并在DON超标的小麦麸皮中开展应用。结果 筛选到高效降解DON的菌株MB-1,该菌株能降解82.3%的DON。鉴定结果表明菌株MB-1被命名为Bacillus aryabhattai MB-1,中文名为阿氏芽孢杆菌MB-1。各组分降解DON的结果表明菌株MB-1产生至胞外的活性物质主导DON的生物降解。菌株MB-1可降解小麦麸皮中80.4%的DON。结论 本研究筛选到降解DON的阿氏芽孢杆菌MB-1,这是首次报道阿氏芽孢杆菌可高效降解DON,为降解去除小麦等谷物中的DON提供了菌种资源。     

人肠道来源霍氏肠杆菌4-2-1的分离及其对枸杞多糖的发酵作用

为了阐明肠道细菌在枸杞多糖吸收过程中的作用,本论文主要针对1株从人体肠道粪便中分离到的细菌进行研究,并将该菌株用于枸杞多糖发酵,并以发酵中细菌总数、pH、多糖含量、还原糖含量和分子量为指标反映发酵特性,初步阐明了枸杞多糖的消化和吸收。结果表明,通过形态学观察和分子生物学鉴定,该菌株为肠道单菌霍氏肠杆菌4-2-1（Enterobacter Hoechnii）,为革兰氏阴性菌,且该菌在发酵到12 h细菌总数达到最大,发酵后,培养基的pH由7.98变为7.75、多糖含量由682 μg/mL变为205.7 μg/mL、还原糖含量由225 μg/mL变为91.32 μg/mL,分子量由8.02 kDa变为3.44 kDa。结果发现,枸杞多糖在经过霍氏肠杆菌发酵后,多糖含量下降为原来的30.2%左右,还原糖含量下降为40.6%左右,分子量下降为42.9%,说明肠道菌能发酵利用枸杞多糖,研究为进一步研究多糖和肠道菌的相互作用提供依据。     

去除脱氧雪腐镰刀菌烯醇乳酸菌的筛选及其作用条件

为了探讨乳酸菌对脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)的脱毒效果,本文利用腌鱼、泡菜、酸马奶中分离得到的乳酸菌,采用共培养的方式,旨在筛选出一株能够高效去除DON的乳酸菌,并对菌体浓度、反应温度、pH进行了研究,同时测定了该乳酸菌对DON的耐受能力。结果表明,从150多株乳酸菌中筛选得到了一株对DON有较高去除能力的副干酪乳杆菌,当菌体浓度达到1010 CFU/mL以上,反应温度为37℃,pH为7时,去除率为40.4%。且副干酪乳杆菌对DON有一定的耐受能力,中低浓度(0~50 μg/mL)的DON几乎不影响乳酸菌的生长,其为应用于饲料以及谷物中霉菌毒素的脱毒提供了依据。     

降解玉米赤霉烯酮菌株的筛选、降解机制及特性研究

玉米赤霉烯酮（Zearalenone,ZEN）是一种易于污染谷物和饲料的雌激素类真菌毒素,严重危害人类和动物健康。采集霉变饲料、土壤等样品,以ZEN为唯一碳源的培养基进行初筛,采用ELISA法筛选对ZEN的降解能力较强的菌株。采用形态学和分子生物学方法对菌株进行鉴定。对菌株的菌体、上清液、细胞内容物分别进行降解实验,探讨其降解机制。研究不同温度、pH、接种量和时间对菌株降解效率的影响。接种到污染ZEN（1 μg/mL）的原料,评价筛选菌株对原料中ZEN的降解效率。通过小白鼠攻毒试验评价菌株的安全性。结果表明从96个分离菌株中筛选出1株ZEN降解能力较强的菌株G-6,最高达到81.19％。菌株为G+,呈杆状,中等大小,能够形成芽孢。16S rDNA序列分析表明G-6和解淀粉芽孢杆菌的亲缘关系最近。不同成分降解试验表明该菌株主要是通过细胞分泌的胞外酶降解ZEN。菌株G-6最佳降解ZEN的条件为：温度37 ℃,pH5.0,接种量3％,培养时间72 h。样品毒素降解实验证明菌株均能100％降解可溶性淀粉、玉米粉、豆粕粉中的ZEN。小白鼠试验结果表明该菌株不具致病性,是一种安全菌株。获得了1株高效降解ZEN的解淀粉芽孢杆菌,为ZEN污染食品和饲料的生物脱毒提供了可能。     

白菜叶际细菌多样性与毒死蜱降解菌筛选及分离鉴定

研究白菜叶际细菌多样性,并从白菜叶际筛选鉴定毒死蜱降解菌。分别采用LB、PDA、改良高氏一号和毒死蜱(100 mg/L)无机盐培养基对白菜叶际上细菌进行分离筛选,得到其细菌浓度分别为1.24×106、1.03×104、2.07×104和2.64×105 CFU/g,表明白菜叶际细菌在数量上存在多样性,共筛选到51株表型差异较明显的细菌。经16S rDNA分子鉴定表明各培养基上优势菌分别是肠杆菌属(Enterobacter)、肠杆菌属(Enterobacter)、节杆菌属(Anthrobacter)和假单孢菌属(Pseudomonas)分别约占各自培养基所分离鉴定菌株的28%、75%、100%和55%。QuEChERS-气相色谱-质谱联用法检测到毒死蜱降解率较高的细菌有11株,其中降解率最高的菌株是沙雷氏菌(Serratia ureilytica)M1,达到52.44%。研究发现,不同培养基从白菜叶际分离鉴定的细菌多样性差异明显,本研究从白菜叶际筛选鉴定出毒死蜱降解菌率较高的细菌菌株,为毒死蜱降解菌的降解特性、应用和机理研究提供了基础。     

辐射降解脱氧雪腐镰刀菌烯醇(DON)的研究

以60Co-γ射线辐照处理脱氧雪腐镰刀菌烯醇(DON)溶液,并采用高效液相色谱法进行DON含量测定,研究γ射线辐照是否能降解溶液中的DON毒素。研究结果表明:高效液相色谱法可以很好的对DON进行定量,最低检测线为0.01μg/mL。60Co-γ射线辐照对DON降解效果显著,剂量为10 kGy时即可使0.5μg/mL DON溶液的降解率达到90%以上。初始浓度对DON降解率有影响,浓度越高,达到一定降解率所需的辐照剂量越大。     

双酶作用体系下呕吐毒素的高效降解

目的 挖掘呕吐毒素(deoxynivalenol, DON)降解酶,应用双酶体系实现呕吐毒素的高效降解。方法 利用生物信息学技术从国家生物技术信息中心(National Center for Biotechnology Information, NCBI)数据库筛选潜在DON降解酶AKR18A2,在大肠杆菌EscherichiacoliBL21(DE3)中进行重组和异丙基-β-D-硫代半乳糖苷(isopropylβ-D-thiogalactoside,IPTG)诱导表达,经镍亲和层析纯化并鉴定AKR18A2的酶学性质,构建德沃斯氏菌(Devosiasp.)来源的DON降解酶QDDH和AKR18A2双酶作用体系,实现DON的高效降解。结果 来自鞘氨醇单胞菌属(Sphingomonas sp.)的呕吐毒素降解酶(AKR18A2)由343个氨基酸组成。该酶属于醛酮还原酶超家族,45℃和pH7.0为最适反应条件。AKR18A2可在24h内降解15.42%DON,而双酶(QDDH和AKR18A2)协同作用4h后对DON的降解率可提高至98.02%。结论 本研究鉴定了一种新型DON降解酶AKR18...     

酶联免疫法检测芽孢杆菌对小麦中呕吐毒素降解效果的研究

以小麦为样品,利用酶联免疫法对芽孢杆菌降解酶降解小麦中呕吐毒素进行分析。试验结果表明,降解酶浓度、反应温度和反应时间是影响降解酶降解DON的关键因素。在降解酶浓度50μg/mL、反应温度30℃、反应时间18 h、pH 8.5的条件下,降解率为88.1%。     

三江镇腌菜中降解亚硝酸盐乳酸菌的筛选和初步鉴定

为筛选具有较强降解亚硝酸盐能力的乳酸菌,本实验经过初筛和复筛从三江镇雪里蕻腌菜中筛选出降解亚硝酸盐能力相对较强的乳酸菌菌株。筛选结果显示菌株对亚硝酸盐最强降解能力达到68h平均降解量32.66μg/mL。采用十六烷基三甲基溴化铵法(CTAB)法提取降解亚硝酸盐能力最强的乳酸菌11号菌株的基因组,测序后进行Blast同源性比较,其与Lactobacillus fermentum strain PL9005的同源性达到98%,并选取同源性较高的菌株构建系统发育进化树,初步鉴定该菌株为Lactobacillus fermentum。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.