复合低聚糖对短双歧杆菌增殖作用的初步研究

以低聚异麦芽糖、低聚木糖及低聚异麦芽糖/低聚木糖(7:3)为碳源,在厌氧条件下增殖短双歧杆菌。研究表明,低聚异麦芽糖、低聚木糖及复合低聚糖对短双歧杆菌有明显的增殖作用,其最佳增殖浓度均为1.0%,且复合低聚糖之间没有协同效应。     

双歧杆菌耐氧菌株的筛选及应用

从婴儿粪便中分离出一株厌氧性无芽孢杆菌，经属和种的鉴定，为长双歧杆菌。经长期耐氧驯化，此菌由厌氧生长驯化成有氧生长良好的菌种，与乳酸菌混合发酵后，可制成口感细腻、气味醇和、酸甜适口，有很好的营养保健功能的双歧杆菌酸奶。     

青春双歧杆菌耐氧驯化及培养条件的响应面法优化

对一株青春双歧杆菌进行耐氧驯化,通过有氧、无氧交替驯化法对出发菌株进行耐氧驯化,得到耐氧能力较强的青春双歧杆菌菌株,在有氧静止培养条件下活菌数可达到4.31×1011cfu/mL。对该耐氧菌株通过响应面法进行培养条件优化,确定培养耐氧青春双歧杆菌的最佳条件:接种量5%,玉米糖化液浓度12.1°Bx,初始pH6.48,培养温度37℃,发酵时间24h。在此条件下菌液最大OD值为1.819,此条件下培养的活菌数为3.05×1012cfu/mL。     

低聚木糖对青春双歧杆菌的增殖

通过体外严格厌氧培养技术,比较葡萄糖、木糖和定向酶解植物半纤维素制备的低聚木糖三种碳源增殖青春双歧杆菌的效果,检测了该低聚木糖的以歧因子作用。研究表明,该低聚木糖对青春双歧杆菌具有良好的增殖效果,青春双歧杆菌在优先利用木二糖和木三糖的同时可能会生成胞外酶,该酶职解聚合度较高木四糖和木五糖使之转变为聚合度理、更易为双歧杆菌的吸收代谢的低聚木糖和木糖。     

动物双歧杆菌乳亚种BZ11的耐氧驯化及降胆固醇性能的研究

为了提高动物双歧杆菌乳亚种BZ11对有氧环境的耐受性,采用逐渐增加培养基中的氧分压和有氧、厌氧条件下交替培养两种方案对其进行了耐氧驯化。通过对驯化前后菌株的生长特性进行分析得出逐渐增加培养基中的氧分压的驯化方案取得了更好的效果。经最优方案驯化后的菌株在有氧条件下培养20 h后,活菌数可达到6.30×10~8CFU/m L,是初始菌株的2.24倍。驯化后菌株的降胆固醇率为27.31%±0.80%,与初始菌株相比没有显著性差异(P0.05)。通过鉴定得出,动物双歧杆菌乳亚种BZ11在耐氧驯化前后保持了相似的形态及生理生化特征。因此,驯化后的菌株有望作为1株潜在益生菌被开发利用。     

双歧杆菌厌氧培养及耐氧驯化的研究

用４种不同驱氧方式的缸内厌氧法培养双歧杆菌，比较其厌氧培养效果。对厌氧的双歧杆菌进行耐氧驯化，耐氧化明显提高，经生理鉴定证明，驯化后的菌株与未经驯化的菌株相比，生理学特性没有发生变化。     

低聚木糖的生理功能和低聚木糖酸奶的研制和检测

功能性低聚糖(益生元)因其独特的生理功能而成为一种重要的功能性食品配料,业已引起全世界的广泛关注.低聚木糖作为功能性低聚糖中对双歧杆菌增殖效果最好的一种产品而得到广泛应用.酸奶制品是一种带有活性的乳酸菌经发酵制成的牛乳产品,它在人体健康、补充营养、疾病疗效上都有其独特的作用.因此,在酸奶制品中添加能使双歧杆菌高效增殖的超强益生元-低聚木糖,使产品既保持了酸奶特有的作用,又提高了肠内有益菌的比例而具有极高的市场开发潜力.本文同时对酸奶中低聚木糖含量的测定方法进行探讨.     

低聚木糖在保健酸奶中的应用

<正>功能性低聚糖因其独特的生理功能而成为一种重要的功能性食品配料,已引起全世界的广泛关注。低聚木糖作为功能性低聚糖中对双歧杆菌增殖效果最好的一种产品而极具开发价值并得到广泛应用。低聚木糖是由2-7个木糖分子以β-1,4糖苷键结合而成的功能性聚合糖,具有独特的功能特性。表现为:高选择性增殖双歧杆菌,功效是其他聚合糖类的10~20倍;不易被消化吸收而直接进入大肠内优先为双歧杆菌所利用,增殖人体有益菌,并抑制其他有害     

你了解低聚木糖吗？

低聚木糖属国际新型低聚糖类产品,是低聚糖中有效用量最少、对双歧杆菌增殖能力最强的产品,通过选择性增殖有益菌、抑制有害菌而被称为“超强双歧因子”,以其功效强、原料简单易得而受到业内人士的关注。日本自1989年实现低聚木糖的工业化生产至今,已经有20多年的历史,其市场仍在不断的扩大,欧洲各国对低聚木糖的开发热情也正不断升温。     

纯双歧杆菌酸奶的研究

将双歧杆菌经过筛选驯化使其岈厌氧驯化成有氧生长良好的菌种，制作纯双歧杆菌酸奶。Ｃ４菌可在牛乳中有氧条件下生长良好，而且品味优良，成本不高，设备简单，不需添加酸奶菌种即可制得纯双杆菌酸奶。     

两歧双歧杆菌耐氧耐酸优良菌株的选育

两歧双歧杆菌通过逐渐增加培养基中氧气分压的方法进行多次耐氧驯化,每次耐氧驯化后进行挑选耐氧的两歧双歧杆菌单菌落,然后将经过耐氧驯化的两歧双歧杆菌菌株再通过降低培养基pH值的方法来进行多次耐酸驯化,每次耐酸驯化后进行挑选两歧双歧杆菌单菌落,以确定所获得的两歧双歧杆菌为纯的耐酸菌株.最终得到了1株对氧和酸的耐受能力有较大提高的两歧双歧杆菌菌株,且耐氧耐酸驯化后的菌株没有发生变异.这有利于两歧双歧杆菌产品的开发和保持两歧双岐杆菌制品有较高的活菌量,具有较好的实际应用价值.     

母乳源长双歧杆菌的筛选鉴定及耐氧驯化

目的：从母乳中筛选双歧杆菌，并提高双歧杆菌在有氧条件下的耐受性。方法：采用稀释涂布法结合16S rDNA鉴定法从母乳中筛选出双歧杆菌，并采用逐渐增加氧分压和有氧厌氧交替的方法进行驯化。结果：筛选得一株MEFZ-2201菌株，通过16S rDNA测序比对，其与长双歧杆菌模式菌（NCBI登录号：ON631733.1）的同源性达到了100%，鉴定为长双歧杆菌（Bifidobacterium longum）。将长双歧杆菌MEFZ-2201进行驯化后，其有氧培养最高的活菌数为8.9×10⁹ CFU/mL，比未经驯化的菌株活菌数提高了一个数量级；此外，驯化前后菌株的生理生化及形态特征并未发生变异；在短链脂肪酸的产生量上，驯化后菌株在厌氧条件下产酸量也显著高于驯化前的菌株。结论：驯化后的长双歧杆菌MEFZ-2201在有氧条件下的活菌数明显提高，有望成为潜在的益生菌菌株进一步开发利用。     

双歧杆菌的分离鉴定与耐氧驯化

本研究从鸡盲肠内容物中分离出单菌落,经菌落菌体形态观察和生理生化鉴定为双歧杆菌.采用逐级增加氧气含量的方法对筛选出的双歧杆菌进行耐氧驯化,以改善双歧杆菌时氧气的耐受力,经过多次驯化,优选出对氧气有一定耐受力、凝乳能力较好,且在贮藏过程中活菌数能够达到保健功能要求的菌株B05.经二次鉴定该菌株保持了双歧杆菌的形态和生理特征.     

长双歧杆菌多因素连续驯化的研究

双歧杆菌因对外界环境的耐受性较差,限制了其规模化生产和实际应用。通过对长双歧杆菌进行连续的耐氧、耐酸以及耐胆盐的驯化,使长双歧杆菌对氧、酸以及胆盐的耐受性有了一定的提高,活菌数和产酸性能都有所提高。耐氧驯化时,通过逐渐增加培养基中的氧分压的方法进行;耐酸驯化时,通过逐渐降低培养基的初始pH的方法进行;耐胆盐驯化时,通过逐渐增加培养基初始胆盐含量的方法进行。实验结果表明,耐氧耐酸驯化后的菌株活菌数能达到9.4×108 cfu/mL,为初始菌的1.92倍;耐胆盐驯化后的菌株在胆盐浓度为0.3%时培养也能保持一定的活菌数,而初始菌株不能存活。     

山药低聚糖对2种双歧杆菌的体外促生长作用

利用体外模型探讨了山药低聚糖对青春双歧杆菌和动物双歧杆菌的生长促进作用。以山药低聚糖取代葡萄糖为碳源添加到双歧杆菌基础培养基中,发现山药低聚糖对青春双歧杆菌和动物双歧杆菌的体外生长具有显著促进作用:随着山药低聚糖的加入,培养液中活菌数增加,p H值降低。当山药低聚糖取代葡萄糖且质量分数为0.5%时,青春双歧杆菌和动物双歧杆菌的最大生长量分别提高了(10.70±4.93)%和(6.02±2.00)%;p H值分别下降(2.64±0.001)%和(3.85±0.65)%。同时,山药低聚糖可提高青春双歧杆菌和动物双歧杆菌的生长速率,使其生长提前进入稳定期。     

枸杞浸提物对青春双歧杆菌发酵的影响

在严格厌氧培养条件下，研究了枸杞浸提物对青春双歧杆菌发酵的影响。结果表明：对青春双歧杆菌发酵起作用的成分主要是枸杞粗多糖；枸杞浸提物的添加能提高青春双歧杆菌的二周残存率和改良青春双歧杆菌发酵鲜牛奶的风味和感官评价；枸杞浸提物和青春双歧杆茼能作为合生素加以开发；同时，对青春双歧杆菌发酵枸杞粗多糖的过程也进行了初步研究。     

The impact of oxygen availability on stress survival and radical formation of Bacillus cereus

Both the growth and stress survival of two model Bacillus cereus strains, ATCC 14579 and ATCC 10987, were tested in three different conditions varying in oxygen availability, i.e., aerobic, microaerobic and anaerobic conditions. Both B. cereus strains displayed highest growth rates and yields under aerobic conditions, whereas the microaerobic and anaerobic cultures showed similar reduced growth performances. The cells grown and exposed microaerobically and anaerobically were more resistant to heat and acid than cells that were cultured and exposed aerobically. On the other hand, the anaerobically grown cells were more sensitive to hydrogen peroxide compared to the (micro)aerobically grown cells. The increased heat- and acid-induced inactivation in aerobic conditions appeared to be associated with intracellular accumulation of excess hydroxyl and/or peroxynitrite radicals, as determined by flow cytometry in combination with the fluorescent reporter dye 3′-(p-hydroxyphenyl) fluorescein. This suggests that radical formation may contribute to inactivation of bacteria in the presence of oxygen, such as in aerobic and microaerobic conditions. No evidence was found for radical formation upon exposure to salt and hydrogen peroxide. The increased resistance to heat and acid in microaerobic and anaerobic conditions shows that oxygen availability should be taken into account when behavior of bacteria, such as B. cereus, in food industry related conditions is investigated, because oxygen availability may affect the efficiency of food preservation conditions.     

Metabolism of lactic acid in fermented cucumbers by Lactobacillus buchneri and related species,potential spoilage organisms in reduced salt fermentations

Recent evidence suggests that Lactobacillus buchneri may play an important role in spoilage-associated secondary fermentation of cucumbers. Lactic acid degradation during fermented cucumber spoilage is influenced by sodium chloride (NaCl) concentration, pH, and presence of oxygen. Objectives were to evaluate these factors on lactic acid utilization by L. buchneri, and to compare the biochemical changes to those which occur during fermented cucumber spoilage. Effects of NaCl (0, 2, 4, and 6% w/w), pH (3.8 vs 5.0), and aerobic environment were investigated using fermented cucumber media (FC) inoculated with spoilage microorganisms. At pH 3.8, L. buchneri degraded lactic acid in all NaCl concentrations. The highest rate of lactic acid utilization occurred in FC with 2% NaCl (P < 0.05). Lactic acid utilization was nearly identical under aerobic and anaerobic conditions, indicating that oxygen does not influence lactate metabolism by L. buchneri. Lactic acid utilization was accompanied by increases in acetic acid and 1,2-propanediol, and Lactobacillus rapi was able to convert 1,2-propanediol to propionic acid and propanol. L. buchneri initiated spoilage in a wide range of environmental conditions that may be present in commercial cucumber fermentations, and L. rapi may act syntrophically with L. buchneri to produce the commonly observed spoilage metabolites.     

Lactic Acid Concentration and Microbial Spoilage in Anaerobically and Aerobically Stored Ground Beef

Lactic acid concentration of coarsely ground beef, packaged in low oxygen permeability casings, is inversely related to sensory acceptability of the meat following regrinding and aerobic storage for six additional days. Samples, reground and stored aerobically after periods of anaerobic storage, were assayed for total aerobic bacterial counts, percentage of gram-positive microflora, and pH. Lactic acid concentration ranged from 130 to 1055 mg per 100g ground beef and increased with anaerobic storage. During 6 days of aerobic storage, both increases and decreases in concentration were noted and related to changes in microbial flora. A positive correlation was found between the proportion of gram-positive bacteria (lactic acid bacteria) and lactic acid and pH.     

新疆地区自然发酵辣椒酱中耐盐乳酸菌的筛选鉴定

以新疆地区自然发酵的辣椒酱为材料,在厌氧条件下采用富集培养法、溶钙圈法对产酸乳酸菌进行初筛;通过测定菌株的产酸能力和NaCl耐受能力进行复筛;通过形态观察、生理生化试验及分子生物学技术对耐盐乳酸菌进行鉴定。结果表明,筛选得到7株产酸乳酸菌,其中,3株产酸能力强、耐盐性能好,分别为菌株B、SS、T,均可耐受7%NaCl。菌株B、SS及T均被鉴定为植物乳酸杆菌（Lactobacillus plantarum）。耐盐性乳酸菌的筛选对提高自然发酵辣椒酱的品质起着重要作用。