发酵乳中双岐杆菌种类快速识别

建立发酵乳制品中双歧杆菌快速识别方法。采用酶解前处理法获取样品中菌体细胞,基于PCR-DGGE技术确定发酵乳中双歧杆菌种属。该方法能准确、快速鉴别双歧杆菌,检出限为105cfu/mL。该方法可用于发酵乳中双歧杆菌的准确识别。     

实时荧光定量PCR法测定发酵乳中双歧杆菌

对实时荧光定量聚合酶链式反应(PCR)技术检测发酵乳中双歧杆菌的DNA提取方法、PCR扩增效率、标准曲线绘制进行探讨,通过比较分析碱式提取法、玻璃珠破碎法和酶解法3种提取方法对发酵乳中总DNA提取效率、4种不同参考菌株的PCR扩增效率以及单一菌株标准曲线与混合菌株标准曲线的计数结果,建立实时荧光定量PCR快速测定发酵乳制品中双歧杆菌数量方法。结果表明：酶解法提取发酵乳中总DNA效果最好,OD260/280比值基本接近1.80,且提取的质量浓度含量最高;不同菌株的PCR扩增效率不同,其中参考菌株1.2213的Ct值与其他3菌株的Ct值存在显著性差异;根据单一菌株绘制标准曲线与混合菌株绘制标准曲线计数结果无显著性差异,后者计数结果更客观、准确。采用酶解法获取样品中的菌体细胞,基于混合菌液绘制标准曲线,采用实时荧光定量PCR技术确定发酵乳中双歧杆菌种属数量,可快速、准确地测定发酵乳中双歧杆菌的数量。     

一种发酵乳中双歧杆菌鉴别培养基计数评估

目的:建立发酵乳中双歧杆菌数量计数测定方法。方法:采用果糖为碳源的鉴别培养基,基于乳酸菌同型发酵和异型菌落形态的差异,借助pH指示剂确定样品中双歧杆菌数量。结果:该培养基所计双歧杆菌数量与对照培养基所计数量在同一数量级且差异不显著(P>0.05)。结论:该培养基可用于发酵乳中双歧杆菌的准确计数。     

双歧杆菌发酵乳对人体的肠道调节作用研究

为研究双歧杆菌发酵乳对人体肠道的调节作用,采用8株双歧杆菌为发酵剂,制备了一款纯双歧杆菌益生菌酸乳,并对入组人群进行试服实验,对比试服前后人体的肠道菌群变化情况以及粪便颜色的变化情况.结果表明:双歧杆菌发酵乳在4℃冷藏条件下放置21 d,双歧杆菌总数可维持在1×107 cfu/mL以上;连续服用2d后,肠道中有益菌如双...     

乳双歧杆菌Probio-M8发酵乳缓解便秘的作用

便秘是一种常见的消化道疾病,益生菌可通过维持肠道菌群平衡、产生有益代谢产物、促进肠道蠕动和缓解炎症等方式改善便秘。该文对乳双歧杆菌Probio-M8发酵乳进行动态体外仿生消化系统测试,并利用人群实验探究发酵乳对便秘的有益影响。结果发现：乳双歧杆菌Probio-M8 具有良好的耐胃肠液能力,能够以活菌的状态进入宿主体内发挥益生功效。受试者在饮用乳双歧杆菌Probio-M8发酵乳后,排便频次、排便类型和排便用力程度均得到改善,其中排便类型和排便用力程度的改善效果在40～50 岁的人群中尤为明显。     

乳双歧杆菌Probio-M8和副干酪乳杆菌PC-01对发酵乳微流变学特性及稳定性的影响

为分析添加益生菌乳双歧杆菌Probio-M8和副干酪乳杆菌PC-01对发酵乳微流变特性和稳定性的影响.以基础发酵剂为对照,分别添加乳双歧杆菌Probio-M8和/或副干酪乳杆菌PC-01,与基础发酵剂复配进行发酵,采用多频扩散波谱法(MS-DWS)分析发酵乳发酵过程中的微流变特性,并测定发酵过程和贮藏期间的滴定酸度、p...     

双歧杆菌牛乳发酵的研究

对经耐氧驯化的双歧杆菌用正交实验法研究了不同菌株，接种量，牛乳固形物学浓度，初始ｐＨ值和培养温度与牛乳发酵后菌浓度，发酵酸度的关系，找出最佳的双歧杆菌牛乳发酵条件，并进行牛乳发酵试验。     

动物双歧杆菌乳亚种HCS04-002发酵条件优化

为实现动物双歧杆菌乳亚种（Bifidobacterium animalis subsp. lactis）HCS04-002的高活菌数培养,获得其生长的最适发酵条件,对发酵工艺和发酵培养基分别进行优化。以菌泥收率为考察指标,通过单因素及正交试验对培养温度、接种量和初始pH值等发酵工艺参数进行了优化;以发酵液活菌数为响应值,通过单因素试验和Box-Behnken试验优化发酵培养基。结果表明,动物双歧杆菌乳亚种HCS04-002最佳发酵条件为：培养温度39 ℃、接种量3%、初始pH值为7.2;最佳发酵培养基组分为：酵母蛋白胨24 g/L、酵母浸出物30 g/L、葡萄糖19 g/L、乳糖11 g/L。在此优化条件下,菌株HCS04-002菌悬液活菌数达2.73×109 CFU/mL。     

含活性多糖发酵乳的研制

探讨了以燕麦和脱脂粉为主要原料，燕麦经双酶水解所得的糖化配以脱脂奶粉，经杀菌冷却，以鼠李糖乳杆菌和两歧双歧杆菌为发酵剂，接种发酵而成的含有活性分且具有保健功能的生物乳，结果表明，该乳的活菌数高达10^11mL^-1。     

Viability During Storage of Selected Probiotic Lactobacilli and Bifidobacteria in a Yogurt-like Product

ABSTRACT: Multiple species cultures, including 2 strains of Streptococcus thermophilus and Lactobacillus acidophilus NCFM plus 1 strain each of Bifidobacterium longum and Lactobacillus casei , were used to make yogurt-like products. The lactobacilli and bifidobacteria were tested for growth in the products and subsequent viability during refrigerated storage. During fermentation, L. casei Com-5 actually declined in numbers, while L. casei E5 and E10 increased about 2 fold. Numbers of B. longum S9 increased about 3 fold while B. longum Com-4 did not increase. During storage, L. acidophilus NCFM appeared stable in all mixtures and both strains of bifidobacteria decreased. Lactobacillus casei E5 and E10 were more stable than was L. casei Com-5.     

酪蛋白糖巨肽对小鼠肠道双歧杆菌增殖水平的影响

采用实时荧光定量聚合酶链式反应（real-time polymerase chain reaction,real-time PCR）分析不同剂量酪蛋白糖巨肽（casein glycomacropeptide,CGMP）对小鼠肠道双歧杆菌增殖水平的影响,揭示乳源CGMP是否有增殖肠道关键益生菌的功能。选用50 只健康BALB/c小鼠,随机分为对照组,安慰组（灌胃生理盐水0.2 mL）,乳源CGMP低、中、高剂量组（灌胃等体积不同质量浓度的乳源CGMP）,灌胃周期为2 周。于灌胃后第0、3、5、7、9、11、15天及停止灌胃后1 周（第21天）采集的小鼠新鲜粪便,并进行粪便菌体基因组DNA抽提。依据双歧杆菌的16S rRNA基因序列设计5 对种属特异性引物,以两歧双歧杆菌（Bifidobacterium bifidum）CICC6071的基因组DNA作为标准品,进行梯度稀释制作标准曲线;分析样品PCR扩增产物的熔解曲线,评价反应的特异性。结果表明：Real-time PCR可准确定量小鼠肠道内双歧杆菌数量;且灌胃中剂量乳源CGMP可以促进小鼠肠道内双歧杆菌的增殖,在灌胃第11天时小鼠肠道内双歧杆菌数量达到最高值,即乳源CGMP对小鼠肠道双歧杆菌的增殖作用存在剂量选择性。     

一种基于荧光PCR法检测虹鳟鱼源性成分方法的建立

目的:建立一种基于荧光聚合酶链式反应技术鉴别虹鳟鱼的检测方法.方法:以细胞色素C氧化酶I为目的基因,设计特异性引物和探针,通过测试引物特异性和模拟检测虹鳟鱼与三文鱼鱼肉混合物验证该体系的检测效果.结果:该虹鳟鱼荧光聚合酶链式反应检测体系具有很好的特异性及灵敏性,可特异性地检测出含1％(w/w)虹鳟鱼的DNA存在.说明该...     

健康成人粪便中双歧杆菌的分离鉴定及其发酵乳体内特性研究

为筛选具有潜在益生功能的双歧杆菌,采用MRS培养基,结合菌落形态观察和16S rDNA基因序列同源性分析,从上海地区健康的成人粪便中分离鉴定双歧杆菌,通过7 L发酵罐发酵试验筛选优良菌株,并利用其制备发酵乳,对发酵乳的体内特性进行研究。结果表明,分离并鉴定到3株长双歧杆菌（Bifidobacterium longum）（编号为P-1、P-2和P-3）,其中菌株P-2制备的发酵乳在稳定期活菌数最高,遗传稳定性好,被确定为优良菌株,并被命名为DD98。菌株DD98制备的发酵乳能显著增加小鼠胃肠道内有益菌、减少有害菌的表达（P＜0.05）,具有调节肠道菌群的作用。此外,能维持小鼠正常的体质量、血常规指数,有利于小鼠脏器的生长。     

Bacterial Community Dynamics of Salted and Fermented Shrimp based on Denaturing Gradient Gel Electrophoresis

The Korean traditional seafood jeotgal is consumed directly or as an additive in other foods to improve flavor or fermentation efficiency. Saeujot, made from salted and fermented tiny shrimp (SFS; Acetes japonicus), is the best‐selling jeotgal in Korea. In this study, we reveal the microbial diversity and dynamics in naturally fermented shrimp by denaturing gradient gel electrophoresis (DGGE). The population fingerprints of the predominant microbiota and its succession were generated by DGGE analysis of universal V3 16S rDNA polymerase chain reaction (PCR) amplicons. Overall, 17 strains were identified from sequencing of 30 DGGE bands. The DGGE profiles showed diverse bacterial populations in the sample, throughout the fermentation of SFS. Staphylococcus equorum, Halanaerobium saccharolyticum, Salimicrobium luteum, and Halomonas jeotgali were the dominant bacteria, and their levels steadily increased during the fermentation process. Certain other bacteria, such as Psychrobacter jeotgali and Halomonas alimentaria appeared during the early‐fermentation process, while Alkalibacterium putridalgicola, Tetragenococcus muriaticus, and Salinicoccus jeotgali appeared during the late‐fermentation process. The members of the order Bacillales were found to be predominant during the fermentation of SFS. Furthermore, S. equorum was identified as the dominant bacterial isolate by the traditional method of culturing under aerobic and facultative anaerobic conditions. We expect that this information will facilitate the design of autochthonous starter cultures for the production of SFS with desired characteristic sensory profiles and shorter ripening times.     

食品中鸡源性成分实时荧光PCR检测方法的建立

目的：建立基于实时荧光聚合酶链式反应技术的食品中鸡源性成分快速检测方法。方法：以鸡线粒体细胞 色素b为目的基因,设计特异性引物和探针,通过特异性、灵敏性实验及模拟混合肉样和市售肉制品检测,对该体 系进行验证。结果：该鸡源荧光聚合酶链式反应检测体系具有很好的特异性及灵敏性,可检测3.5 pg/μL鸡源DNA 的存在;经含鸡源成分的模拟混合肉样检测,证实体系抗干扰能力强;并且通过市售食品检测表明体系可用于定性 加工食品中的鸡源成分。结论：所建立的鸡源引物探针体系具有特异性好、灵敏度高、快速高效等优点,可用于对 食品中鸡源性成分的掺假鉴别。     

Innovative Methods for Removal of PCR Inhibitors for Quantitative Detection of Plesiomonas shigelloides in Oysters by Real-Time PCR

A quantitative assay for Plesiomonas shigelloides in pure culture and oysters based on the real-time polymerase chain reaction (Rti-PCR) was developed. The methodology involved the treatment of oyster tissue homogenates with formaldehyde, differential centrifugation, and treatment of samples with activated charcoal coated with Pseudomonas fluorescens. With seeded oyster tissue homogenates, without formaldehyde or coated charcoal treatments, the lowest level of detection for P. shigelloides was 1?×?10⁷ genomic targets per gram of tissue, equivalent to 2.5?×?10⁵ genomic targets per Rti-PCR. The addition of 4% formaldehyde to tissue homogenates reduced the minimum level of detection of P. shigelloides to 1?×?10⁵ genomic targets per gram of tissue, equivalent to 2.5?×?10³ genomic targets per real-time PCR. The treatment of tissue homogenates with only activated charcoal coated with P. fluorescens reduced the minimum level of detection of P. shigelloides to 1?×?10⁴ genomic targets per gram, equivalent to 2.5?×?10² genomic targets per real-time PCR, without DNA purification or enrichment. The combination of adding 4.0% formaldehyde to oyster tissue homogenates and treating with coated charcoal reduced the level of detection of P. shigelloides to 1?×?10³ genomic targets per gram, equivalent to 25 genomic targets per real-time PCR. The linear range of detection was from 1?×?10³ to 1?×?10⁶ genomic targets per gram without enrichment.     

Innovative Methods for Removal of PCR Inhibitors for Quantitative Detection of Plesiomonas shigelloides in Oysters by Real-Time PCR

A quantitative assay for Plesiomonas shigelloides in pure culture and oysters based on the real-time polymerase chain reaction (Rti-PCR) was developed. The methodology involved the treatment of oyster tissue homogenates with formaldehyde, differential centrifugation, and treatment of samples with activated charcoal coated with Pseudomonas fluorescens. With seeded oyster tissue homogenates, without formaldehyde or coated charcoal treatments, the lowest level of detection for P. shigelloides was 1 × 10⁷ genomic targets per gram of tissue, equivalent to 2.5 × 10⁵ genomic targets per Rti-PCR. The addition of 4% formaldehyde to tissue homogenates reduced the minimum level of detection of P. shigelloides to 1 × 10⁵ genomic targets per gram of tissue, equivalent to 2.5 × 10³ genomic targets per real-time PCR. The treatment of tissue homogenates with only activated charcoal coated with P. fluorescens reduced the minimum level of detection of P. shigelloides to 1 × 10⁴ genomic targets per gram, equivalent to 2.5 × 10² genomic targets per real-time PCR, without DNA purification or enrichment. The combination of adding 4.0% formaldehyde to oyster tissue homogenates and treating with coated charcoal reduced the level of detection of P. shigelloides to 1 × 10³ genomic targets per gram, equivalent to 25 genomic targets per real-time PCR. The linear range of detection was from 1 × 10³ to 1 × 10⁶ genomic targets per gram without enrichment.