一种肠膜明串珠菌Leuco4发酵乳的特性

制备出一种含肠膜明串珠菌Leuco4的无任何添加剂的发酵乳,采用肠膜明串珠菌Leuco4发酵乳与常规发酵乳按质量比1∶4混合,并对所得发酵乳产品进行黏度、脱水收缩敏感性、质构及感官测试.结果表明:21d保质期内,与对照组相比,含肠膜明串珠菌Leuco4的发酵乳,持水性佳,黏度、口感、稳定性均能达到理想状态,且不含任何添加剂,符合清洁标签产品的要求.     

肠膜明串珠菌对奶牛产奶量和乳品质的影响

肠膜明串珠菌是美国食品药物管理局认为安全的40种益生菌菌种之一,它有改善机体肠道环境,增强机体免疫力等功能。试验将肠膜明串珠菌发酵液应用于奶牛饲料中,作为奶牛饲料的一种益生菌添加剂,观察肠膜明串珠菌发酵液对奶牛奶产量及其品质的影响。结果表明,试验期实验组奶牛平均日产奶量比实验前期提高了12.03%(P0.01),奶中乳蛋白质量分数、乳糖质量分数及干物质质量分数显著提高(P0.01),分别提高了1.76%、1.23%和0.76%,而乳脂率没有明显变化(P0.05)。     

植物乳杆菌和肠膜明串珠菌共培养时的选择性计数法

基于植物乳杆菌ST-Ⅲ和肠膜明串珠菌BD1710在添加不同碳源的MRS固体培养基上的菌落形态差异,建立2株菌共培养时的2种选择性计数方法,分别为差值法和色差法。结果表明:2种方法均能够满足选择性计数的要求,且差值法中植物乳杆菌ST-Ⅲ和肠膜明串珠菌BD1710的平均检出率(97.2％和96.4％)均略高于色差法(95.4％和94.0％),因此差值法更适用于对精确度要求较高时数据的采集,而色差法具有操作简便和成本较低的优势,更适用于工厂进行快捷的活菌数量检测。     

肠膜明串珠菌乳糖及半乳糖代谢差异性研究

在不同碳源的化学限定培养基（chemically defined medium,CDM）和脱脂乳中对8 株肠膜明串珠菌（Leuconstoc mesenteroides）进行培养,测定其生长、产酸及活菌数变化情况。结果表明：各菌株在以乳糖、半乳糖为单一碳源的CDM培养基中的生长情况存在明显差异,菌株LM1、LM2、LM4和LM8在以乳糖为单一碳源的CDM培养基中生长情况良好,菌株LM2、LM3、LM5和LM8在以半乳糖为单一碳源的CDM培养基中活力较强,但生长情况弱于乳糖环境;在脱脂乳环境下,实验菌株的活菌数于发酵初期明显增长,培养8 h后进入稳定期,发酵终点pH值在6.0以上;初步对比各菌株与乳糖、半乳糖代谢相关基因的差异性,基因与表现型的相关性还需结合乳糖水解酶活性及乳糖、半乳糖残留量进一步分析。     

肠膜明串珠菌发酵液对奶牛乳房炎及生产性能的影响

肠膜明串珠菌是乳酸菌中明串珠菌属的重要菌种,也是常见的益生菌菌种之一。它既能改善机体肠道环境,提高饲料的吸收利用率,又能拮抗致病菌,提高机体免疫力。实验将肠膜明串珠菌发酵液添加到奶牛日粮中,观察其对奶牛隐性乳房炎及奶牛生产性能的影响。结果表明：每头奶牛每天日粮中添加200mL发酵液（肠膜明串珠菌菌数约为10^9个／mL）,连续使用7d,试验期间,在隐性乳房炎奶牛中,隐性乳房炎的治愈率为70％;在健康奶牛中,与试验前比较,奶产量提高了11．26％（P〈0．05）,奶中的乳蛋白率、乳糖质量分数和乳脂率分别提高了2．06％（P〈0．05）、1．45％（P〈0．05）、1．63％（P〈0．05）。实验表明,日粮中添加肠膜明串珠菌发酵液既能提高奶牛的免疫力,在一定程度上治疗隐性乳房炎,又能提高奶牛的生产性能。     

一种通过肠膜明串珠菌发酵的花样奶布丁的研制

目前市售布丁主要是调制型奶布丁,是根据口味差异调制所需配料,加入明胶等凝固而成,虽有一些"半发酵型"的布丁产品,主要是以酸奶为原料进行调制而成,但其凝固成型过程主要依赖于添加的各种稳定剂,无法兼顾到美味、营养和健康.为此,本文研究了一种以脱脂乳和番茄汁为介质、基于肠膜明串珠菌发酵的花样奶布丁,其保留了牛乳中的各种营养物...     

明串珠菌应用研究进展

明串珠菌是一类进行异型发酵的革兰氏阳性兼性厌氧乳酸菌,是众多传统发酵制品中的优势菌群,可应用于食品、化工、医疗等领域。本文从目前国内外研究现状出发,概述明串珠菌的分离筛选及特性,介绍了有关明串珠菌基因组学、蛋白质组学、代谢组学的研究进展,进而对其应用情况进行概括,旨在为今后明串珠菌能够更有效地应用于工业化生产和生活提供理论依据。     

肠膜明串珠菌胞外多糖的研究进展及其在饲料业中的应用前景

综述了肠膜明串珠菌胞外多糖的存在形式、组成成分、酶促合成过程、生成影响因素及提高产量的技术,介绍了肠膜明串珠菌胞外多糖的功能及用途,探讨了专供发酵饲料使用的肠膜明串珠菌的菌株选育问题、饲用肠膜明串珠菌微生态制剂的生产问题及低聚糖益生元饲料添加剂开发问题。     

乳与乳制品中明串珠菌的分离鉴定

从内蒙古通辽市科左后旗和扎鲁特旗牧民家庭乳样中分离到61株乳酸菌,并进行乳酸菌的分离鉴定。结果显示,其中有肠膜明串珠菌葡聚糖亚种2株,假肠膜明串珠菌1株,明串珠菌分离率为4．9％。     

柠檬明串珠菌BD1707的胞外多糖合成酶特性

柠檬明串珠菌是一类从发酵谷物和蔬菜中分离出的革兰氏阳性乳酸菌,该类菌株能表达多种胞外多糖合成酶来合成不同类型的胞外多糖.对柠檬明串珠菌BD1707在番茄汁中培养24、72?h的发酵液进行硫酸铵沉淀和非变性聚丙烯酰胺凝胶电泳原位活性测试.结果表明:柠檬明串珠菌BD1707可以分泌分子质量约为150、90、80?kDa?3...     

Production of bacteriocin by Leuconostoc mesenteroides 406 isolated from Mongolian fermented mare's milk,airag

The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral‐pH cell‐free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat‐stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α‐chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24–36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut‐off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin‐producing Leuconostoc strain from airag. An application to fermented milks would be desired.     

Production of a bacteriocin‐like inhibitory substance by Leuconostoc mesenteroides subsp. dextranicum 213M0 isolated from Mongolian fermented mare milk,airag

Strain 213M0 was selected with productivity of a bacteriocin‐like inhibitory substance (BLIS) among 235 strains of lactic acid bacteria (LAB) isolated from Mongolian fermented milk ‘airag’. Strain 213M0 was species‐identified as Leuconostoc mesenteroides subsp. dextranicum by morphological observation, carbohydrate fermentation profiling and sequencing the 16S rRNA gene. Incubation temperature proper to produce the BLIS was 25°C rather than 30 and 37°C, and the production actively proceeded during the exponential growth phase of the producer cells. Antibacterial effect of BLIS 213M0 was limited to all nine strains of Listeria sp. bacteria and seven strains of LAB cocci among 53 tested strains, which corresponds to a typical feature of the class IIa pediocin‐like bacteriocins. BLIS 213M0 was not inactivated in every broad pH range solution (pH 2.0‐11.0), and was stable against storage at 25°C for 1 week and heating at 121°C for 15 min under pH 4.5. Peptide frame of BLIS 213M0 was confirmed by inactivation with some peptidases, and then its molecular weight was estimated to be 2.6‐3.0 kDa using an in situ activity assay following sodium dodecyl sulfate polyacrylamide gel electrophoresis. The estimated size was different from the other Leuconostoc bacteriocins already reported. These results suggest that BLIS 213M0 would be a novel listericidal bacteriocin.