X-Gal在双歧杆菌分离与活菌计数方面的应用研究

利用大多数双歧杆菌具有半乳糖苷酶且活性较高的特性，在NPNL培养基中加入X—Gal(5-溴-4-氯-3-吲哚-8-D-半乳糖苷)作为底物，双歧杆菌水解底物释放出吲哚，产生颜色反应。双歧杆菌菌落呈深蓝色，乳酸菌和其它细菌一般为白色或淡蓝色。将X—Gal应用于不同样品中双歧杆菌分离和活菌计数进行对比。这种方法能比较准确的反映双歧制品和婴儿粪便中双歧杆菌的数量，并且大大减少了分离鉴别双歧杆菌的工作量。     

双歧杆菌的分离鉴定及保藏性能研究

为丰富发酵剂及益生菌菌种资源,从内蒙古阿拉善盟采集7份新生婴儿粪便样品,在传统细菌分离方法的基础上,通过添加莫匹罗星锂盐和X-Gal(5-溴-4-氯-3-吲哚-β-D-半乳糖苷)改良基础培养基,快速有效地分离获得双歧杆菌。结合全自动微生物分析系统和API20A试剂条鉴定菌种。结果共分离获得6株双歧杆菌,其中3株动物双歧杆菌,2株青春双歧杆菌,1株短双歧杆菌。试验验证甘油浓度为70%时冷冻保藏效果最佳。     

新疆维吾尔族肠道中高产胞外多糖双歧杆菌的筛选及其抗氧化活性

使用Wilkins-Chalgren厌氧菌琼脂和BSM培养基作为筛选平板,结合重复基因外回文序列-聚合酶链式反应和16S rRNA序列分析,对新疆维吾尔族婴儿及其母亲粪便中的双歧杆菌(Bifidobacterium)进行分离鉴定,并筛选出高产胞外多糖的双歧杆菌,测定其多糖的抗氧化活性以及菌株的耐受性和黏附性。结果显示,20份粪便样品中共分离出52株双歧杆菌,其中假小链双歧杆菌(B. pseudocatenulatum)14株,假长双歧杆菌(B. pseudolongum)8株,两歧双歧杆菌(B.bifidum)9株,短双歧杆菌(B.breve)7株,长双歧杆菌婴儿亚种(B.longumsubsp.infantis)5株,动物双歧杆菌乳亚种(B. animal subsp. lactis)6株以及长双歧杆菌(B. longum)3株。经过表型初筛和苯酚-硫酸法复筛,共筛选出7株高产胞外多糖的双歧杆菌,37℃发酵36 h后胞外多糖产量均可达400 mg/L以上。抗氧化活性实验结果表明7株双歧杆菌所产的胞外多糖对过氧化氢自由基、超氧阴离子自由基、羟自由基和1,1-二苯基-2-三硝基苯肼自由基均有一定的清除能力。此外,菌株BF66-16相较于其他几株双歧杆菌具有较强的胃肠液耐受性以及黏附性,因此来源于婴儿粪便的BF66-16可以作为潜在的抗氧化菌株应用于制药和食品工业中。     

双歧杆菌和乳酸菌β-半乳糖苷酶转糖基作用的研究进展

双歧杆菌和乳酸菌作为一般认为安全的微生物,是β-半乳糖苷酶（β-galactosidase,β-gal）的较好来源。部分双歧杆菌和乳酸菌菌株能够产生具有转糖基活力的β-gal,以乳糖为底物可合成具有益生作用的低聚半乳糖（galactooligosaccharides,GOS）,而GOS产物的产量和组成受到β-gal的来源以及反应条件的影响。因此,本文总结了能够产生具有转糖基活力的β-gal的双歧杆菌和乳酸菌菌株,比较了两类来源的β-gal的酶学性质,并重点阐述了这两类β-gal在GOS合成中的应用。     

豆渣水溶性膳食纤维对双歧杆菌增殖的影响

对豆渣水溶性膳食纤维（SDF）的功能性进行了研究,分别以人体肠道内典型的长双歧杆菌和婴儿双歧杆菌为实验菌株,从体外观察了SDF促进双歧杆菌增殖的效果,讨论了底物浓度对双歧杆菌增殖效果的影响。结果表明豆渣水溶性膳食纤维对婴儿双歧杆菌和长双歧杆菌的增殖都具有促进作用;并且对混合菌株的增殖效果更为显著。     

双歧杆菌在发酵乳中活性的研究

分别使用两歧双歧杆菌和长双岐杆菌制作酸乳并冷藏21d,应用AMC,RMS培养基检测样品的双歧杆菌活菌数。发酵乳中的双歧杆菌的浓度达到10^8-10^9CFU/mL,在21d的冷藏中二种双歧杆菌的活菌数都超过了最小保健剂量10^6CFU/mL。RMS培养基同样有效地分离两歧双歧双歧杆菌和长双歧杆菌,可以采用涂布法和倾注法进行操作,RMS是对酸乳中双歧杆菌计数的最适宜的选择性培养基,使用AMC培养基由于涂布法造成较低的活菌计数。     

澳新批准一种新来源的β-半乳糖苷酶作为加工助剂

正据澳新食品标准局消息,9月5日澳新食品标准局发布通报,修订《澳新食品标准法典》附表18,批准一种新来源的β-半乳糖苷酶作为加工助剂。据了解,这种β-半乳糖苷酶来自转基因地衣芽孢杆菌(Bacillus licheniformis),该菌株带有分离自两歧双歧杆菌Bifidobacterium bifidum的β-半乳糖苷酶基因。     

双抗夹ELISA法检测双歧杆菌反应条件的优化

研究利用双抗夹心酶联免疫吸附法（Double-antibody Sandwich Enzyme-Linked Immunosorbent Assay,Double-antibody Sand-wich ELISA）快速检测双歧杆菌（Bifidobacterium）的最佳反应条件。使用实验室自制的兔抗两歧双歧杆菌免疫血清和鼠抗两歧双歧杆菌免疫血清,利用方阵法对两种血清抗体的反应浓度进行筛选,之后对包被液、封闭液、封闭时间及底物作用时间进行比较和选择,从而确定运用双夹心ELISA法快速检测双歧杆菌的最佳反应条件。最佳反应条件分别为：兔抗两歧双歧杆菌免疫血清和鼠抗两歧双歧杆菌免疫血清反应浓度分别为1︰1280,1︰320,包被液浓度0.05 mol/L（pH值为9.6）的Na2CO3-NaHCO3,封闭液为质量分数为5%的BSA-PBS,封闭30min,底物作用时间为30 min。优化了双抗夹心ELISA法检测双歧杆菌的反应条件,为双歧杆菌的血清学检测提供了参考。     

以葵花籽油为底物生物转化共轭亚油酸双歧杆菌的筛选

运用快速扫描法,筛选了10株可利用游离态亚油酸为底物高产共轭亚油酸的双歧杆菌菌株;然后以富含非游离态亚油酸的葵花籽油为底物,与初筛得到的高产菌株共培养后检测反应体系中共轭亚油酸的含量。结果表明,部分短双歧杆菌可将葵花籽油转化为共轭亚油酸,其中短双歧杆菌FFJND12M6的转化率最高,可达14.35%。     

食品中双歧杆菌显色培养基的研制

双歧杆菌在肠道中的有益功能已受到人们的高度关注。为建立准确、快捷的双歧杆菌定性定量方法,我们以乳酸杆菌(LBS)琼脂为基础,添加能够抑制或促进双歧杆菌生长的物质,同时添加酶显色底物,通过正交试验,经方差分析,确定最佳配方,形成双歧杆菌显色培养基。研制的双歧杆菌显色培养基具有成本低、快速、特异性高、准确性好等优点,满足目前食品行业检测双歧杆菌的需求,为今后生产和研究提供理论依据。     

Probiotics and prebiotics--perspectives and challenges

Owing to their health benefits, probiotics and prebiotics are nowadays widely used in yogurts and fermented milks, which are leader products of functional foods worldwide. The world market for functional foods has grown rapidly in the last three decades, with an estimated size in 2003 of ca US$ 33 billion, while the European market estimation exceeded US$ 2 billion in the same year. However, the production of probiotics and prebiotics at industrial scale faces several challenges, including the search for economical and abundant raw materials for prebiotic production, the low-cost production of probiotics and the improvement of probiotic viability after storage or during the manufacturing process of the functional food. In this review, functional foods based on probiotics and prebiotics are introduced as a key biotechnological field with tremendous potential for innovation. A concise state of the art addressing the fundamentals and challenges for the development of new probiotic- and prebiotic-based foods is presented, the niches for future research being clearly identified and discussed.     

常用消毒灭菌法及其机理与应用

介绍了采用消毒灭菌方法,有加热消毒法,紫外线辐射法和化学药剂消毒法。常用化学药剂有醛类、含氯消毒剂、醇类消毒剂以及高锰酸钾、生石灰等,阐释了消毒与灭菌两个概念的区别。     

European citizen and consumer attitudes and preferences regarding beef and pork

This paper presents the combined mid-term findings of the consumer research components of two EU Sixth Framework Programme integrated projects concerning meat, ProSafeBeef and Q-PorkChains. The consumer pillar of ProSafeBeef carried out eight focus group discussions in May 2008, in France, Germany, Spain and the UK. Q-PorkChains conducted a large-scale, web-based, consumer survey in January 2008 in Belgium, Denmark, Germany, Greece and Poland. The first project provides a set of qualitative data from a small cohort of focus groups and the second a set of quantitative data from a larger consumer sample. This paper draws together the main findings of both projects and provides a comprehensive overview of European citizens’ and consumers’ attitudes towards and preferences regarding beef and pork. In general, consumers consider meat to be a healthy and important component of the diet. Consumers support the development of technologies that can improve the health attributes of meat products and guarantee eating quality, but they have a negative view of what they see to be excessive manipulation and lack of naturalness in the production and processing of beef products. In the Q-PorkChains study consumer and citizen segments are identified and profiled. Consumer segments were built upon the frequency and variety of pork consumption. The citizen segments were built upon their attitudes towards pig production systems. Overall, the relationship between individuals’ views as citizens and their behaviour as consumers was found to be quite weak and did not appear to greatly or systematically influence meat-buying habits. Future studies in both projects will concentrate on consumers’ acceptance of innovative meat product concepts and products, with the aim of boosting consumer trust and invigorating the European beef and pork industries.     

毛霉型低盐速成豆豉工业化生产工艺与设备

本文介绍了毛霉型低盐速成豆豉的工业化生产工艺及生产线的关键设备。     

原花色素及其开发应用

对原花色素的结构、化学特性、制备、分析方法、应用前景作一综述,并重点讨论其生理功能,为在功能性食品、药物、化妆品等领域的深入研究和开发提供参考。     

组学技术与果蔬采后质量和安全控制

果蔬可以提供营养, 有利于人类健康, 而果蔬的后熟及其与环境的相互作用会影响果蔬采后的质量和安全。对果蔬生物学过程的了解和掌握是减少果蔬采后损失和保障果蔬采后质量和安全的关键。在过去的10多年, 基于组学技术的系统生物学在了解果蔬后熟及其与环境相互作用的分子机制方面得到了越来越多的应用。本文对此做了细致的总结, 指出了存在的不足, 并提出了未来的发展方向。     

天然香精香料与生物技术

天然香精香料是高价值的精细化工产品和食品添加剂,但原料来源有限且提取成本高。利用生物技术生产这类产品具有广阔的前景。简述了发酵工程、酶工程、细胞工程和基因工程在香精香料中的应用,并探讨了生物技术在香精香料中的应用前景。     

益生素、益生菌与结肠癌

介绍了益生素和益生菌及其作用机理。在动物模型中，有大量的数据证实益生素和益生菌能够预防癌症．而在人体内还没有直接实验证据。它们抑制癌症的确切机理目前尚不清楚，其抑制机理可能是：肠道菌群代谢活动的改变，肠道理化环境的改变，潜在的致癌物质的黏附和降解，肠道菌群的改变、抗癌或抗诱变物质的形成、提高宿主的免疫应答、影响宿主的生理活动以及发酵不能被消化的食物并形成有益代谢产物。     

节能节水型印染助剂和设备的现状

从节能、节水、缩短工艺流程和环保的角度出发,介绍了国内外研制开发的一系列新型节能、节水型印染助剂和染整设备。     

Heritability and correlations for body condition score and dairy form within and across lactation and age

The objectives of the current study were to investigate the relationship between body condition score (BCS) and dairy form and changes in genetic parameters for BCS and dairy form within and across lactations and age. Body condition score and dairy form were obtained from the Holstein Association USA, Inc. Records were edited to include those cows classified between 24 and 60 mo of age and between 0 and 335 d in milk (DIM). A minimum of 20 daughters per sire and 15 cows per herd-classification visit were required. The dataset consisted of 135,178 records from 119,215 cows. Repeatability, multiple trait, and random regression models were used to analyze the data. All models included fixed effects for herd-classification visit, age within lactations 1, 2, and 3 or higher, and 5th-order polynomials for DIM. Random effects included sire and permanent environment for all models. Random regression models included age at classification nested within sire or DIM and lactation number nested within sire. Genetic variance for both BCS and dairy form was lowest in early lactation and highest in midlactation. Genetic correlations within and across lactations were high. The genetic correlation between DIM 0 in lactation 1 and DIM 305 in lactation 3 was estimated to be 0.77 for BCS and 0.60 for dairy form. The genetic correlation estimate between 30 mo of age at classification and 50 mo of age at classification was 0.94 for both dairy form and BCS. The repeatability models appeared to generate accurate evaluations for BCS or dairy form at all ages and stages of lactation.