新疆传统酸奶中乳酸菌的筛选鉴定及菌相分析

酸奶是新疆各少数民族经常食用的一种乳制品。从新疆采集的22个酸奶样品中共分离出56株乳酸菌,通过形态特征观察、生理生化实验、糖发酵实验等传统鉴定方法,结合16S r DNA序列分析对其进行鉴定。结果表明,新疆传统酸奶中菌相构成为德氏乳杆菌(Lactobacillus.delbrueckii subsp.)46株(占总分离株的82%);发酵乳杆菌(Lactobacillus.fermentum)2株(4%);瑞士乳杆菌(Lactobacillus.helveticus)2株(4%);嗜酸乳杆菌(Lactobacillus acidophilus)1株(2%);鸡乳杆菌(Lactobacillus.gallinarum)2株(4%);屎肠球菌(Enterococcus faecalis)1株(2%);耐久肠球菌(Enterococcus canis)2株(4%)。说明新疆传统酸奶中德氏乳杆菌为优势菌。      

新疆传统酸奶中乳酸菌的筛选鉴定及菌相分析

酸奶是新疆各少数民族经常食用的一种乳制品。从新疆采集的22个酸奶样品中共分离出56株乳酸菌,通过形态特征观察、生理生化实验、糖发酵实验等传统鉴定方法,结合16S r DNA序列分析对其进行鉴定。结果表明,新疆传统酸奶中菌相构成为德氏乳杆菌(Lactobacillus.delbrueckii subsp.)46株(占总分离株的82%);发酵乳杆菌(Lactobacillus.fermentum)2株(4%);瑞士乳杆菌(Lactobacillus.helveticus)2株(4%);嗜酸乳杆菌(Lactobacillus acidophilus)1株(2%);鸡乳杆菌(Lactobacillus.gallinarum)2株(4%);屎肠球菌(Enterococcus faecalis)1株(2%);耐久肠球菌(Enterococcus canis)2株(4%)。说明新疆传统酸奶中德氏乳杆菌为优势菌。     

不同品牌酸乳中德氏乳杆菌的分离鉴定及RAPD分析

从不同品牌的10 种酸乳中分离得到10 株德氏乳杆菌(Lactobacillus delbrueckii),经生理生化实验及特异性PCR 鉴定,L.d3、L.d4、L.d5、L.d6、L.d8、L.d10 为德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp.bulgaricus),L.d1、L.d2、L.d7、L.d9 为德氏乳杆菌乳酸亚种(Lactobacillus delbrueckii subsp. lactis)。利用24 个随机引物对上述10 株德氏乳杆菌进行随机扩增DNA 多态性分析,并使用NTSYSpc-2.10e 软件对扩增图谱数据进行处理,得出10 个菌株之间的遗传相似系数矩阵及聚类分析图。结果表明,10 个菌株相互间的遗传相似系数在0.4167～0.8833 之间,不同菌株间存在一定的亲缘关系及遗传异质性。     

基于高通量测序技术鉴定酸浆水中的微生物

利用高通量测序技术和传统的分离纯化相结合的方法,以及API 50CHL乳杆菌鉴定试剂盒对酸浆水中的微生物群落组成进行分析,结果表明:酸浆水中的优势菌群为乳酸杆菌;从酸浆水中分离出66株乳酸菌,其中好氧菌36株,厌氧或兼性厌氧菌30株;经试剂盒生化鉴定,得到3种乳酸杆菌L1、L2、L3,其中L1为乳明串珠菌(Leuconostoc lactis),有27株;L2为德氏乳杆菌(Lactobacillus delbrueckii subsp.lactis),有13株;L3为植物乳杆菌(Lactobacillus plantarum),有26株。     

高加索酸奶中乳酸菌的分离与鉴定

从自然发酵的5份酸奶样品中,通过平板划线等方法分离筛选乳酸菌。经形态特征,生理生化特性及糖发酵试验等,筛选到12株乳酸菌,分别为:乳杆菌7株,其中:3株德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp.bulgaricus),3株瑞士乳杆菌(Lactobacillus hel-veticus),1株罗伊氏乳杆菌(Lactobacillus reuteri);乳酸球菌5株,包括3株嗜热链球菌(Streptococcus thermophilus),2株乳酸乳球菌乳脂亚种(Lactococcus lactis subsp.Cremoris)。     

新疆阿勒泰地区传统酸乳中乳酸菌的分离鉴定及菌相分析

采用传统纯培养方法对采集自新疆阿勒泰地区的15份传统酸乳样品中的乳酸菌进行分离纯化,运用16S rDNA序列分析方法进行属种鉴定。结果表明,分离的36株乳酸菌属于乳杆菌属(Lactobacillus)的5个种或亚种。其中发酵乳杆菌(Lactobacillus fermentum)8株,植物乳杆菌(Lactobacillus plantarum)6株,开菲尔乳杆菌(Lactobacillus kefiri)6株,干酪乳杆菌(Lactobacillus casei)3株,鼠李糖乳杆菌(Lactobacillus rhamnosus)6株,德氏乳杆菌保加利亚亚种(Lactobacillus bulgaricus)3株,瑞士乳杆菌(Lactobacillus helveticus)4株。其中发酵乳杆菌为新疆阿勒泰地区传统酸乳中的优势菌种,占总分离株的22%。     

新疆伊犁地区乳品中发酵菌种的筛选及产酸性能研究

通过传统分离方法从新疆伊犁州乳品中初步分离纯化出71株乳酸菌,其中具有明显产酸凝乳特性的乳酸菌8株,经生理生化鉴定以及16S rRNA序列比对分析,确定8株乳酸菌的种属分别为德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp.bulgaricus)、开菲尔乳杆菌(Lactobacillus kefiranofaciens)、发酵乳杆菌(Lactobacillus fermentum)、植物乳杆菌(Lactobacillus plantarum)、乳酸明串球菌(Leuconostoc lactis)和粪肠球菌(Enterococcus faecalis)。对8株乳酸菌的生长性能、产酸性能、后酸化性能、感官特性等多个指标进行分析得出,德氏乳杆菌BSTS6-1、BSTS6-3、BSTS6-4生长速度快、产酸速率高,发酵乳风味纯正、组织形态良好且菌株后酸化能力弱,符合酸乳发酵菌种的基本特征。     

传统分离培养结合PCR-DGGE技术分析传统乳制品中的乳酸菌

采用传统培养分离方法结合聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术对传统乳制品中乳酸菌种群结构进行研究。结果表明:用传统分离与分子鉴定方法得到5种乳酸菌,其中,乳酸片球菌(Pediococcus acidilactici)为优势菌群,对通过PCR-DGGE方法得到的9条16S rDNA条带序列进行了比对,结果表明瑞士乳杆菌(Lactobacillus helveticus)的丰度最高,是酸奶样品中主要的优势菌群,乳酸片球菌(Pediococcus acidilactici)为次优势菌群。传统分离法与PCR-DGGE技术结合能够更有效、更全面地分析传统乳制品中微生物的群落结构及优势菌群。     

新疆蒙古族和哈萨克族传统乳制品中乳酸菌多样性的比较

传统发酵乳制品是新疆少数民族不可或缺的一类食品,为了研究同一地区不同民族传统乳制品中乳酸菌种类的差异性,从新疆和布克赛尔县采集了17份哈萨克族酸奶和8份蒙古族酸奶,通过传统培养和16S rDNA基因序列分析方法共分离得到42株乳酸菌,有30株分离自哈萨克族样品,12株分离自蒙古族样品,其中优势菌群均为Pediococcus acidilactici(乳酸片球菌)。除了优势菌群,两种样品中都分离出了Lactobacillus plantarum(植物乳杆菌)和Enterococcus durans(耐久肠球菌)。哈萨克族样品中还分离出了Lactobacillus fermentum(发酵乳杆菌)、Lactobacillus paracasei(类干酪乳杆菌)、Lactobacillus crustorum(面包乳杆菌),而蒙古族样品中分离出了Weissella cibaria(食窦魏斯氏菌)。      

鄂尔多斯地区酸粥细菌多样性分析及乳酸菌的分离鉴定

以采集自内蒙古鄂尔多斯地区的8个酸粥样品为研究对象,利用Illumina MiSeq高通量测序技术,对样品进行细菌菌群结构及多样性研究,分离鉴定其优势菌株。结果表明:8个样品中的细菌主要来自厚壁菌门(Firmicutes)和变形菌门(Proteobacteria),乳酸杆菌属(Lactobacillus)和醋酸杆菌属(Acetobacter)为优势菌属。乳酸杆菌属在各样品中占比最高,为42.63%～97.49%。SZ1、SZ2样品与其他样品的菌群结构差异较大,可能与不同采集时间有关。对上述样品中的乳酸菌进行分离纯化,通过生理生化试验结合分子生物学方法,鉴定获得1株干酪乳杆菌(Lactobacillus casei),1株发酵乳杆菌(Lactobacillus fermentum),2株植物乳杆菌(Lactobacillus plantarum)和4株副干酪乳杆菌(Lactobacillus paracasei)。上述研究结果为酸粥工业化生产提供菌种资源和理论依据。     

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