MiSeq测序研究散装酱卤鸭肉贮藏期间微生物群落多样性

为研究散装酱卤鸭肉贮藏过程中微生物变化规律,揭示其腐败本质,以期为确定其特定腐败菌(Specific Spoilage Organisms,SSO)提供依据,本文采用Mi Seq测序分析其在4℃和25℃贮藏过程中微生物群落多样性。结果表明,样品在4℃和25℃贮藏过程中细菌和真菌物种多样性在总体上均呈现下降趋势。样品贮藏初期优势细菌是Weissella sp.、Staphylococcus sp.、和未分类的肠杆菌科,优势真菌是Debaryomyces sp.IZ_1257和Lodderomyces elongisporus。4℃贮藏中后期,肺炎嗜冷杆菌(Psychrobacter pulmonis)和Staphylococcus sp.为主要优势细菌;而25℃贮藏中后期的优势细菌则为Weissella sp.、Staphylococcus sp.、溶酪大球菌(Macrococcus caseolyticus)和未分类的肠杆菌科。4℃、25℃贮藏中后期样品中最主要优势真菌均为Debaryomyces sp.IZ_1257。相比较于传统方法,Mi Seq测序提供的微生物多样信息更接近于样品微生态,更能够全面解析各环境样品微生物多样性。     

基于培养鉴定法和高通量测序技术分析郫县豆瓣微生物群落结构演替

结合传统培养鉴定法和Illumina MiSeq测序技术分析郫县豆瓣不同发酵阶段的微生物群落演替。结果表明,辣椒发酵阶段细菌以Gracilibacillus sp.,Bacillus sp.,Staphylococcus sp.,Oceanobacillus sp.为主,真菌以Candidasp.,Zygosaccharomyces sp.,Aspergillus sp.为优势菌属;蚕豆发酵阶段具有较高的微生物菌落总数,混合发酵阶段展现了丰富的微生物多样性,这两个阶段细菌均以Bacillus sp.丰度最高,而真菌以Candidasp.,Zygosaccharomyces sp.为优势菌属。研究结果可为郫县豆瓣的控制发酵和品质提升提供科学支撑。     

冷却牦牛肉贮藏过程中优势菌的 PCR-变性梯度凝胶电泳分析

应用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术,研究托盘保鲜膜包装的冷却牦牛肉在4℃贮藏过程中的微生物多样性及其动态变化.直接从样品中提取细菌总的DNA,采用降落PCR扩增16S rDNA的V3可变区序列,再通过DGGE得到动态变化的指纹图谱,并对主要条带进行测序分析.结果表明:检测到的优势腐败菌为Pseudomonas sp.(假单胞菌)、Lactococcus sp.(乳球菌)、Acinetobacter sp.(不动杆菌)、Brochothrix thermosphacta(热死环丝菌)、Enterobacteriaceae bacterium(肠杆菌科细菌),此外还检测到Uncultured Citrobacter sp.(非培养的柠檬酸杆菌)和Staphylococcus sp.(葡萄球菌)     

利用高通量测序分析云南两个地区豆豉微生物群落的多样性

豆豉是一种具有独特风味的传统发酵食品。研究豆豉的微生物群落多样性,对于提高豆豉质量和食用安全性具有重要意义。本研究分别采取云南西双版纳州的景洪市和勐海县的两个豆豉样品,提取DNA,PCR扩增细菌16S r DNA和真菌ITS区域并进行焦磷酸测序,通过分析测序所得结果比较两个豆豉样品中的细菌和真菌群落多样性。结果表明:景洪样品的最优势细菌是Leuconostoc mesenteroides,其次是Leuconostoc fallax。勐海样品中丰度最高的细菌是Staphylococcus gallinarum,其次是Tetragenococcus halophilus。两个样品中都含有少数序列与能够产细菌素的Weissella confusa和Weissella cibaria具有较高相似性。两个样品的优势真菌都是耐盐的Candida etchellsii和Candida versatilis。总之,西双版纳的豆豉具有较高的微生物群落多样性,以嗜盐菌居多。     

酱块发酵过程中真菌和细菌群落的演替

豆酱是中国传统的发酵豆制品。酱块制作是豆酱发酵的前期阶段,为后期发酵提供丰富的微生物和酶制剂,对豆酱的品质至关重要。为了探究自然发酵豆酱酱块发酵过程中微生物多样性,采用第二代测序Illumina MiSeq方法对采集自开原的4个不同发酵阶段的酱块样品进行微生物多样性分析。结果表明:在属级水平上,共鉴定出21个真菌分类群,其中毛霉菌(Mucor)、青霉菌(Penicillium)、德巴利氏酵母属(Debaryomyces)和根霉菌(Rhizopus)为优势类群;细菌共鉴定出40个细菌分类群,其中乳杆菌(Lactobacillus)、魏斯氏菌(Weissella)和肠球菌(Enterococcus)为优势类群。豆酱酱块中多样性的真菌和丰富的细菌在发酵过程中可能共同发挥特定的作用。本研究阐明了传统发酵豆酱酱块的微生物群落特征,揭示了传统酱块发酵过程中真菌和细菌的群落演替,为豆酱发酵过程控制奠定了理论基础。     

基于高通量测序的江西特色发酵豆豉中微生物群落多样性及其特征分析

目的:采用高通量测序技术,研究江西特色发酵豆豉中细菌和真菌等微生物的群落多样性及特征,以了解和提高产品质量和食用安全性。方法:采集江西南昌稻香园调味食品有限公司豆豉样品,经gDNA提取,分别对细菌16S rDNA和真菌ITS区域进行PCR扩增及MiSeq测序,根据统计的测序数据进行物种注释、丰富度聚类及α-多样性分析。结果:高通量测序获得细菌Tag数目36633个,OTU数目114个,经物种注释,主要为蓝细菌门(Cyanobacteria)和厚壁菌门(Firmicutes),以蓝细菌门未分类属(Cyanobacteria Chloroplast Unclassified)、葡萄球菌属(Staphylococcus)、乳杆菌属(Lactobacillus)为主;真菌Tag数目47117个,OTU数目8个,经物种注释,几乎全为接合菌门横梗霉属(Lichtheimia)。结论:江西豆豉细菌具有丰富的微生物群落多样性和特色的菌群组成结构。     

汉中地区浆水发酵过程中微生物群落演替及其功能预测

该研究利用Illumina MiSeq测序技术，对发酵不同阶段的汉中浆水进行细菌与真菌多样性检测分析。结果表明，随着发酵的进行，细菌群落的丰度和多样性较为稳定，真菌群落的丰度和多样性先增加后趋于稳定。3个发酵时期中优势细菌门均为厚壁菌门（Firmicutes），优势细菌属为乳植杆菌属（Lactiplantibacillus）、腐败乳杆菌属（Loigolactobacillus）、魏斯氏菌属（Weissella）、寡碳乳杆菌属（Paucilactobacillus）、明串珠菌属（Leuconostoc）等；优势真菌门为担子菌门（Basidiomycota）和子囊菌门（Ascomycota），优势真菌属主要有双胞菌属（Cystofilobasidium）、白冬孢酵母属（Leucosporidium）、镰刀菌属（Fusarium）、德巴利酵母属（Debaryomyces）、Holtermanniella等。整个发酵过程中优势菌属相对含量有明显波动，参与发酵的真菌种类多于细菌。微生物功能预测结果显示，细菌中涉及代谢、遗传信息处理和环境信息处理的通路比例分别为（74.11±0.11）%、（12....     

酸汤子玉米面团中微生物多样性分析

酸汤子是我国北方地区一种营养丰富、风味独特的民族传统食品,深受满族及东北人民的喜爱。多样的微生物在酸汤子玉米面团的营养品质形成过程中,发挥着极其重要的作用,然而到目前为止,对满族传统发酵食品酸汤子面团中的微生物菌群多样性,仍不明确。以不同地区采集的酸汤子玉米面团为研究对象,利用聚合酶链式反应结合变性梯度凝胶电泳技术探究了酸汤子中微生物菌群多样性。结果表明:在9份酸汤子面团中共鉴定出14种真菌,分别为Saccharomyces castellii、Geotrichun candidum、Simplicillium lanosoniveum、Rhizochaete sulphurosa、Guehomyces pullulans、Debaryomyces hansenii、Fusarium culmorum、Trichoderma brevicompactum、Oryza lonqistaminata、Geotrichun fraqrans、Galactomyces candidum、G.geotrichum、Geotrichum sp.和Galactomyces sp.。鉴于S.castellii在多数样品中被检测,推测其为酸汤样品中真菌的优势发酵菌种。鉴定出4种细菌,分别是Bacillus pumilu、Lactobacillus tucceti、L.plantarum和Weissella paramesenteroides。由于W.paramesenteroides在多数样品中被检测出,推测其为酸汤样品细菌的优势菌群。     

基于高通量测序技术分析豆腐乳中微生物多样性

采用高通量测序技术对4种不同来源发酵豆腐乳中微生物的多样性和丰度进行比对分析。结果表明,纯种发酵与自然发酵豆腐乳样品微生物菌群多样性差异较大,从不同豆腐乳样品中共检测得到3个优势细菌门（平均相对丰度＞1%）、6个优势真菌门、13个优势细菌属和19个优势真菌属;共有优势细菌属为假单胞菌属（Pseudomonas）、乳杆菌属（Lactobacillus）、透明颤菌属（Vitreoscilla）、魏斯氏菌属（Weissella）、不动杆菌属（Acinetobacter）和明串珠菌属（Leuconostoc）,其中,假单胞菌属在自然发酵豆腐乳中平均相对丰度最高（62.05%）;共有优势真菌属为酵母属（Saccharomyces）、曲霉属（Aspergillus）、德巴利氏酵母属（Debaryomyces）、短梗霉属（Aureobasidium）、假丝酵母属（Candida）和有孢圆酵母属（Torulaspora）,其中酵母属在纯种发酵豆腐乳中平均相对丰度最高（44.42%）。     

河南传统面食发酵剂中微生物菌群结构分析

以河南省不同地区传统面食发酵剂作为研究对象，采用Illumina MiSeq 高通量测序技术分析其真菌和细菌菌群结构。测序真菌共检出7 个属，涉及234 个OTU；细菌共检出8 个属，涉及423 个OTU。结果表明：优势真菌属主要是酵母属（Saccharomyces）和威克汉姆酵母属（Wickerhamomyces）；细菌绝大部分是乳酸菌，优势细菌属主要有乳酸杆菌属（Lactobacillus）、明串球菌属（Leuconostoc）、魏斯氏菌属（Weissella）和片球菌属（Pediococcus）等。6 个样品的真菌菌群多样性分析结果表明郑州样本的Shannon 指数最大，Simpson 指数最小，证明其真菌物种多样性最高。细菌群落多样性分析结果表明商丘样本的Shannon 指数最大，Simpson 指数最小，说明其细菌物种多样性最高。在不同地区的样品中优势真菌和细菌菌属的种类和含量差异较大。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

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

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status